Coastal Fluxes in the Anthropocene: Chapter 5 - Synthesis of main findings and conclusions

Chapter 5Synthesis of Main Findings and Conclusions

Peter Burbridge, Robert W. Buddemeier, Martin Le Tissier and Robert CostanzaContributor: Laurie Ledoux

2 For the purposes here, a definition of human dimensions is“the effects of human activity on large physical and biologi-cal systems, the impacts of environmental change on peopleand societies, the responses of social systems to actual or an-ticipated environmental change, and the interactions amongall these processes” (US NRC Committee on the Human Di-mensions of Global Change).

cerning the rate and scale of change in human pressuresamong the different bio-climatic regions.

Integration of natural and social science dimensionsin the LOICZ programme has clarified the principal prob-lems and issues associated with global environmentalchange and consequent sustainability of human uses ofcoastal systems, including:

� eutrophication;� pollution;� changing erosion/sedimentation equilibrium;� mounting impoverishment in the biodiversity of es-

tuarine waters and coastal seas through a reductionin river-borne nutrients and organic matter;

� loss of ecosystem goods and services that help to sus-tain food security, economic development and im-provements in social welfare; and

� increasing vulnerability of human societies to natu-ral coastal hazards affecting settlements, public andprivate investment, property and lives.

Given the pivotal role that coastal areas and resourcesplay in sustaining the social and economic welfare of upto 50% of Earth’s population, the major challenge thathumans face today is to recognise and manage the con-sequences of adverse impacts from both natural and hu-man-induced changes to coastal systems. History hasshown how difficult it is to motivate nations to work to-gether in addressing these issues at a global scale. How-ever, much can be achieved at regional, nation-state andlocal levels to sustain human use of coastal systems. Thiscan be done through initiating improvements in themanagement of human activities within catchments aswell as within the marine and terrestrial components ofthe “coastal zone.” LOICZ methodologies have allowedup-scaling of local information to a global scale that can

5.1 Global Change and Sustainable Use ofEarth’s Coastal Zones

It is clear that global change to the environment is hav-ing a major influence on the functioning of coastal sys-tems and their ability to sustain human development. Akey outcome of the first 10 years of LOICZ is that, al-though major river systems have a profound influenceon coastal and nearshore marine systems at a regionallevel, the mounting pressures from human developmentand their effects on coastal systems are felt most acutelyat small to medium individual catchment scales. Further-more, it is becoming increasingly evident from the LOICZstudies that the cumulative effects of human-inducedchanges in small- to medium-scale river systems may wellbe greater than those attributed to major river systems.

The LOICZ research described in the preceding chap-ters has demonstrated the importance of biogeochemi-cal fluxes, nutrients and sediments from river catchmentsin the coastal zone for the availability of living and non-living resources for human society. The outcomes fromLOICZ research have demonstrated that investigation ofchanges to coastal systems cannot be confined withinadministrative boundaries. Instead, studies need to beoriented towards watershed- and catchment-based per-spectives to study coastal dynamics and to integrate theresults with management of human activities. This rein-forces the emerging concepts of integrated coastal man-agement where the “coastal zone” is treated as part of adynamic continuum linking terrestrial and marine com-ponents, rather than as an isolated “zone” that can bemanaged without reference to natural and human-in-duced changes to hydrology, or fluxes of materials inupland and oceanic systems.

The river basins or catchments (LOICZ-Basins) stud-ies have helped to integrate the human dimensions2 toglobal environmental change by identifying the majorsocial and economic drivers that lead to pressures with adirect or indirect influence on the state of ecosystemsand corresponding impacts on biological, chemical, geo-physical, social and economic conditions. These studiesdemonstrated common as well as unique features con-

202 CHAPTER 5 · Synthesis of Main Findings and Conclusions

then be down-scaled and applied to other local areaswhere there is a paucity of information. A major benefitfrom the LOICZ thematic studies is the provision of sci-entific evidence that could strengthen information avail-able for policy, planning and management initiatives atsmall to medium to large scales. At the same time, LOICZstudies have greatly enhanced our understanding of theresponses of coastal systems at a global scale.

5.2 Progress in Meeting IGBP-LOICZ Goals

During the past 10 years, the scientific effort of the LOICZproject has been directed towards answering the genericquestion:

How will changes in land use, sea level and climate altercoastal ecosystems, and what are the wider consequences?

The broad goals of LOICZ in addressing this questionhave been:

1. Determination at global and regional scales:a fluxes of materials between land, sea and atmos-

phere through the coastal zone;b capacity of coastal systems to transform and store

particulate and dissolved matter;c effect of changes in external forcing conditions on

the structure and functioning of coastal ecosystems.2. Determination of how changes in land use, climate,

sea level and human activities alter the fluxes and re-tention of particulate matter in the coastal zone andaffect coastal morphodynamics.

3. Determination of how changes in coastal systems, in-cluding responses to varying terrestrial and oceanicinputs of organic matter and nutrients, will affect theglobal carbon cycle and the trace gas composition ofthe atmosphere.

4. Assessment of how responses of coastal systems toglobal change will affect the habitation and usage byhumans of coastal environments, and to develop fur-ther the scientific and socio-economic bases for theintegrated management of coastal environments.

These goals and objectives have been addressed by aglobal network of scientists in which the active and col-laborative participation of scientists from developed anddeveloping countries has been vital to the successful con-duct of the research and dissemination of results of theLOICZ programme. This network has compiled manylocal case studies, which form the data and informationbase that has been up-scaled for construction of the glo-bal synthesis.

Progress has been made in generating a comprehen-sive overview of the changes in Earth system processesaffecting the coastal zone, the role of coastal systems inglobal change and the current state of coastal metabo-

lism. This includes identifying simple proxies in the formof demographic and hydrological parameters, that cansupport the prediction of the state of coastal systems.Typology approaches supported by analytical and visu-alisation software have been developed to assist in theinterpolation of these results for remote areas where pri-mary information is lacking, thus enabling a first orderup-scaling to a global synthesis.

Important scientific questions have been answered.For example, estimates of carbon fluxes and their modi-fication by natural systems and human activities incoastal regions have been developed through the up-scal-ing of local nutrient budget data collated and analysedby LOICZ. Another success is the identification andanalyses of nutrient loads transmitted to coast systemsand an evaluation of the global increase in nutrients overrecent decades. The LOICZ research has also providednew insights into the influence of global climate changeon the dynamics of coastal systems with respect to sedi-ments, groundwater and sea-level and how these mayinfluence the long-term habitation of coastal areas andsustainable use of natural resources.

The main findings from the thematic studies producednew information of value in broadening our understand-ing of global systems and addressing management chal-lenges at various scales, centring upon three areas of in-vestigation:

1. The Material Fluxes effort relied more heavily on scien-tific evaluation of fluxes, measurements and models.Although most of the results stemmed from paper stud-ies and scientific workshops, new data were assembledthrough the publication of compilations of informationand model results and a series of field measurementsand experiments. The latter activity was a joint LOICZ/SCOR working group on submarine groundwater dis-charge. The results of the overall effort consist prima-rily of an enhanced understanding of the issues involvedin coastal zone fluxes, of the variety of forcing functionscontrolling them, and in the development of an inven-tory of relevant tools and the understanding of whereand how they may best be applied.

2. The Biogeochemical Budget effort pursued a coursethat was in many ways intermediate between, and con-ceptually linking, the other two – using local exper-tise to assess the nature and status of biogeochemicalfluxes in coastal waters in a quantitative, inter-com-parable fashion. The systematic classification of budg-ets and associated flux data, and the terrestrial andmarine systems they represent, provided a basis foridentifying potential functional similarities amongmeasured and similar unstudied systems – the typo-logical up-scaling approach.

3. The River Basins effort used a standardised approachto identify and assemble regional “expert judgment”

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assessments of the characteristics and conditions ofdrainage basins and their known or perceived rela-tionship to the conditions of the associated estuarineor coastal waters. These assessments, based on a mix-ture of quantitative measures and qualitative judg-ments, were codified in terms of ranked variables thathave the potential to be formulated in at least semi-quantitative fashion, and related to typological defi-nitions and known mechanisms of change.

Each of these thematic areas was underpinned by theuse of the Driver-Pressure-State-Impact-Response (DPSIR)framework in socio-economic evaluations (Turner et al.1998) and was enhanced through model developmentsand application in regional sites (e.g., Southeast Asia)where terrestrial socio-economic models were linkedwith coastal ecosystem (biogeochemical) models (Talaue-McManus et al. 2001). Awareness of this method of as-sessing local and regional global changes and manage-ment was transferred to other parts of the world throughcollaborative involvement of LOICZ scientists with in-ternational capacity building initiatives by Intergovern-mental Organisations (IGOs). Companion work (Wilsonet al.2004) revised and extended the values for the world’secosystem goods and services, earlier estimated by Cos-tanza et al. (1997).

These efforts were not only individually productive,but complementary and convergent in both methods andresults. A final, more rigorously integrative evaluation ofcoastal zone functions in the global context remains themajor challenge for the second phase of LOICZ (http://www.loicz.org). The results and relationships summa-rized in this chapter lay out the new framework and start-ing point.

5.3 Key Findings

LOICZ research has substantiated, and enhanced ourunderstanding of, the critical importance of four princi-pal issues concerning the sustainable human use ofcoastal areas and their ecological systems.

1. The coastal domain is the most dynamic part of theglobal ecosystem and the realm most subject to natu-ral and anthropogenically-induced global change. Theobvious trends over the last century, of increasinghuman population in the coastal lands and the alliedpressures on coastal systems, will undoubtedly serveas a powerful catalyst for direct changes in the coastalzone and more broadly for Earth’s systems.

2. At a global scale, coastal systems play a significantrole in regulating global change. The concentrationof population and inadequate planning and manage-ment of economic activities in coastal areas have a

major influence on the health and productivity of allEarth’s coastal systems. At a regional and local scale,there are specific actions that can be taken within thecoastal realm to ameliorate anthropogenic influenceson atmospheric, marine and terrestrial systems. How-ever, there are limits to what can be achieved at a glo-bal scale through adjustments to policy, investmentand management of human activities within coastalzones.

3. Coastal change cannot be studied or managed in iso-lation from river systems. Anthropogenic impacts onhydrological systems, sediment and materials fluxesand energy transfers within river basins have a fargreater influence on coastal areas and on the resilienceand stability of coastal systems than is commonlyunderstood. It is therefore critically important to cou-ple the management of human activities within riverbasin systems and management of human activitieswithin coastal areas in order to:a avoid irreversible loss of the dynamic equilibrium

that allows coastal systems to function and con-tinue to help regulate global carbon cycles, mate-rial fluxes and energy budgets;

b maintain the flows of renewable resources and en-vironmental services that help to sustain humansocieties;

c meet international standards of environmentalconduct, such as control of marine pollution andconservation of biological diversity; and

d reduce the rate of increase in vulnerability of hu-man societies located within coastal regions tonatural and human-induced hazards.

4. Although large river systems such as the Amazon andthe Mississippi generate the major input of freshwa-ter, energy and materials into the coastal and marineenvironment, it is the small- to medium-sized riverbasin systems that are more sensitive to human-in-duced and climatic influences on hydrology and ma-terial fluxes. For instance, the same town on a largeriver system/catchment has far less impact than on asmall river system because of temporal and spatialscales as well as buffering capacity. The buffering ca-pacity of large versus small systems is reflected inthe time between change and when a response isfound/observed, and in the magnitude of the re-sponse. A large system will show a slow response toland clearing, with a small increase in turbidity,whereas a small catchment will show a fast responseand much higher increases in turbidity becausedownstream impacts of changing land use andchanges in hydrology are much greater. In compari-son to the large river systems, much less is knownabout these smaller rivers – how they are changing,the response of associated coastal systems and theirrole in global change.

5.3 · Key Findings


5.3.1 The Coastal Domain

The Earth’s coastal regions form the interface betweenthe marine and terrestrial realms and are the focus ofhuman-induced and natural global change. Physical, bio-logical and chemical processes drive land–ocean inter-actions that result in a series of unique coastal habitatsadapted to strong terrestrial and/or marine forcings.Human societies have developed a strong dependenceon the natural resources and products available fromthese ecosystems.

Coastal processes and natural ecosystems are subjectto changes which vary greatly in geographic scale, tim-ing and duration and lead to very dynamic and biologi-cally productive coastal systems that are vulnerable toadditional pressures resulting from human activities. Thesustainability of human economic and social develop-ment is vulnerable to natural and human-induced haz-ards as a result of our poor understanding of the dynam-ics of land-ocean interactions, coastal processes and theinfluence of poorly planned and managed human inter-ventions.

There is mounting concern about the sustainabilityof human use of the coastal zone from degradation inecosystems and habitats reducing the availability of re-sources and amenities. The LOICZ project developed newinsights into how human dimensions and natural sys-tems interact and are intimately combined in the vari-ous pressures on, and resultant state of, the coastal do-main. However, it is apparent that existing tools and con-cepts for measurement and analyses are inadequate tomeet the needs for understanding human–nature inter-actions. There is heterogeneity in the expression of pres-sures, changes and state of coastal systems and that lim-ited comprehensive data and information are readilyavailable and/or accessible at all scales of measurement.In particular, societal demands on the scientific commu-nity for information and knowledge to resolve manage-ment issues are increasing despite the relatively poor his-tory of communication between science and users (Bie-secker 1996, Kremer and Pirrone 2000). In such cases,participatory approaches in programme design, imple-mentation and assessment can prove fruitful (Crossland2000). Frequently asked questions relate to sustainabil-ity issues (e.g., How do we identify wise-use options?),planning and management approaches (e.g., How can wemeasure and predict impacts and changes?) and policy-related developments (e.g., What are the risks and vul-nerability to change?). Answers to such questions arecritical to the sustainable improvement of human eco-nomic and social conditions. Over the past decade, therehave been major advances in our scientific understand-ing of the chemical, physical and biological processes thatmaintain the health, productivity and functions of coastal

ecosystems that are vital in providing socio-economicgoods and services for humankind. Methods and con-cepts for integrating information across disciplines alsocontinue to be developed.

While our scientific knowledge of coastal zone proc-esses has improved, there remain major challenges forassessing the impact of regional and global change acrossmultiple temporal and spatial scales on the functioningof coastal ecosystems. At the local level these interactingchallenges are fourfold:

� Identify, model and analyse global changes that affecta local coastal system, such as natural variability, cli-mate change and associated changes in the hydrologi-cal cycle, and those due to changes in global economy/trade and policy.

� Identify, model and analyse regional (trans-boundaryand supra-national) changes that are primarily the re-sult of regional and national drivers and pressures inthe coastal zone,

� Model and assess regional changes at the level of rivercatchments (e.g., damming, land use change) that af-fect the downstream coastal zone.

� Map existing stakeholders interests and differences inthe perception of coastal values at regional scales –differences that need adaptation of management op-tions to local social conditions, beliefs and attitudes.

Sustainable management and its supporting researchhave to take these interacting changes into account andthis requires a holistic approach. In this holistic approachthe coastal region is part of the catchment–coast con-tinuum and part of a regional socio-economic frame-work, which is embedded in a global setting. Many stud-ies have dealt with isolated aspects of this continuum andframework, while a few integrated studies have dealt witheither coastal zone management or river catchment man-agement. The various studies show significant differencesin spatial and temporal scales.

The hydrological system that links atmospheric, ter-restrial and ocean processes forms the fundamental or-ganising framework for developing our understandingof such complex relationships and changes. The LOICZprogramme has therefore given major emphasis to theuse of river basins as a functional unit for examining bothnatural and human-induced changes and their effects onterrestrial, coastal and ocean systems.

5.3.2 River Basins: Assessment of Human-inducedLand-based Drivers and Pressures

LOICZ adapted and used the Driver-Pressure-State-Im-pact-Response (DPSIR) framework to illustrate the domi-nant pressures and effects on the global coastal realm.

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The drivers and pressures on coastal systems that weobserve and measure are now predominantly the resultof societal function and human behaviour and may beamenable to management and policy decisions (response)in specific situations. In the first instance, small to medium-sized and relatively undeveloped catchments may offer agreater opportunity to modify policies, infrastructure in-vestment and land-use and resources management asintervention will probably be less constrained by cross-boundary issues than would highly developed catchmentsof major river systems. Further, it is increasingly apparentthat the forcing on coastal ecosystems by most naturaldrivers and pressures is being greatly modified in both ex-tent and intensity by human activities. The characteris-tics of the LOICZ-Basins studies can be summarised as:

1. Predominantly founded on qualitative data and infor-mation gathered through a series of regional work-shops, which developed “expert” typologies whereinquantitative thresholds associated with Driver-Pres-sure-Response parameters have been estimated.

2. Confirming the importance of human-induced changesto land cover, hydrology and material fluxes comparedwith the effects of cyclic climatic and tectonic events.

3. Creating a mechanism for an overview of human-in-duced changes in river catchments and their effect oncoastal systems.

4. Showing that scale issues related to institutional andbiogeochemical parameters are highly variable at bothlocal and regional levels.

5. Having current management practices which are strong-ly focussed on only water resources issues that hinderthe adoption of more integrated management ap-proaches based on consideration of water in a widergoods and services context. Such a strategy would in-tegrate hydrological and material fluxes into policy,investment and resources management strategies andplans, and institutional structures.

6. In a data-rich situation, it is possible to demonstratethat participatory approaches to the integration ofscience and management can enrich problem defini-tion and the development of pragmatic and effectivemanagement of coastal systems use based on the con-tinuum from catchment through to coastal ocean sys-tems. Scenario development is a primary tool to fos-ter such integration.

7. Having identifiable trends and factors that influenceprogressive change. One example is the periodic flush-ing of agricultural chemicals into an estuary result-ing from major storms. This creates a change in thenutrient fluxes over time and will influence biologi-cal production in the estuary and adjacent coastalwaters. While such events can be monitored in a dis-crete time frame, the period over which land man-agement practices or agricultural policies will change

to mitigate such events will extend over a far longertime-scale.

An example of the relevance of these findings to thepolicy arena can be seen in consideration of the Euro-pean Union’s Water Framework Directive (Text Box 5.1).

Where change impacts coastal systems that do not havean inherent inertia to the change imposed upon them fromchanges in the catchment basin, change cannot be studiedor managed in isolation, because it is caused by humanactivities that are predominantly land-based. Examplesinclude damming that reduces the supply of sediment re-sulting in major changes in the stability of coastal systems,such as a coastline shifting from an accretionary to an ero-sional state. Changing land use, for example deforestation,can increase erosion and sediment delivery as agriculturalsoils are more prone to erosion compared with forestedones. Changing land use can also increase the supply ofnutrients, with some time-delay due to the buffering effectof soils after the land-use change occurs. The nature of land-based activities and their impact on the coastal zone maygo through a cycle that reflects the industrial landscapeand regulatory efforts (Fig. 5.1).

The DPSIR framework adopted by LOICZ has beensuccessfully used in scoping and ranking pressures anddrivers within river basins across continents. The over-all trend of the drivers affecting coastal seas indicates anaccelerated catchment-based influence on coastal zonesand their functioning within the Earth’s system. Althoughpressures and drivers are similar between basins, nota-ble differences exist at the large-scale regional level withregard to ranking as well as future trends. Damming isconsidered an over-riding issue on the African continent;it is also an important issue in other countries, but lessso than eutrophication. The main causes of increased

Fig. 5.1. Linkages between governance, economic development andglobal change in the coastal zone (from Salomons et al. 1995)

5.3 · Key Findings


inputs of nutrients are urbanisation and agriculture inSouth America and Asia. However, in Europe where ef-fective sewage treatment is widespread, agriculture is the

main cause of coastal eutrophication. In certain areas ofEurope, regulatory efforts have decreased phosphorusrelease and this decrease has caused, or is expected to

Given the generally large fluxes of nutrients and contaminantsfrom catchments, any policy response seeking to improve coastalwater quality should target activities at the catchment scale. Oneexample of such integrated catchment-coastal zone managementpolicy is the recent European Union Water Framework Directive(WFD), adopted in June 2000. The new directive integrates pre-viously existing water legislation, updates existing directives ac-cording to new scientific knowledge and strengthens existing le-gal obligations to ensure better compliance (Kaika and Page 2002).Earlier legislation on water had gone through two distinct phases(Kallis and Butler 2001, Kaika and Page 2002). The first one(1975–1987) was primarily concerned with public health and set-ting standards for water quality for different uses (drinking, fish-ing, shellfish and bathing). In the second phase (1988–1996), pri-orities shifted towards pollution control, in particular for urbanwastewater and agricultural runoff, with an effort to set emis-sion limit values for different pollutants in water bodies. The thirdphase, which saw the birth of the WFD, came after a state of theenvironment report showed that these policies had been effec-tive in terms of reducing point-source pollution, but that diffusepollution remained a major problem (EEA 1998, Kaika and Page2002). The new Directive is an attempt at more integrated andsustainable water management, expanding the scope of water pro-tection for the first time to all waters, from surface water togroundwater, and from freshwater ecosystems to estuaries andcoastal waters. It encapsulates the new directions in Europeanenvironmental policy institutionalised in the Maastricht Treatyin 1992 and further reinforced by the Amsterdam Treaty in 1997.The Member States agreed to the objective of sustainable devel-opment as a Community policy, to the Community responsibil-ity for environmental policy within the limits of subsidiarity, andto the integration of environmental policy into other commu-nity policies. More specifically the precautionary principle, theprinciple of prevention of pollution at source and the polluter-pays principle were all adopted (Barth and Fawell 2001).

Kallis and Butler (2001) point out that the directive intro-duces both new goals and new means of achieving them (i.e.,new organisational framework and new measures). The overallgoal is a “good” and non-deteriorating “status” for all waters(surface, underground and coastal). This includes a “good” eco-logical and chemical quality status for surface water. Ecologi-cal status involves criteria for assessment divided into biologi-cal, hydro-morphological and supporting physico-elements forrivers, lakes, transitional and “heavily modified” water bodies.For groundwater, the goal is a “good status” defined in terms ofchemical and quantitative properties. A principle of “no directdischarges” to groundwater is also established, with some ex-emptions (e.g., mining). In addition, “protected zones”, includ-ing areas currently protected by European legislation such asthe Habitats Directive, should also be established, with higherquality objectives.

Organisationally, measures to achieve the new goals will beco-ordinated at the level of river basin districts, i.e., hydrologicalunits and not political boundaries. Authorities should set up RiverBasin Management Plans, to be reviewed every six years, basedon identifying river basin characteristics, assessing pressures andimpacts on water bodies and drawing on an economic analysisof water uses within the catchment. Monitoring is also an essen-tial component, determining the necessity for additional meas-ures. Finally, an important innovation of the Directive is to widenparticipation in water policy-making: river basin managementplans should involve extensive consultation and public access toinformation.

Text Box 5.1. An example of policy response at catchment scale: the European Union Water Framework Directive

Laure Ledoux

Following the DPSIR terminology, the main “response” elementof the WFD is the program of measures (Fig. TB5.1.1). “Basic” meas-ures should be incorporated in every river basin management plan,at a minimum including those required to implement other EUlegislation for the protection of water. If this doesn’t suffice toachieve good water status additional measures should be intro-duced following a “combined approach”, which brings togetherthe two existing strategies of Environmental Quality Standards(EQS – the legal upper limits of pollutant concentrations in waterbodies) and Emission Limit Values (ELV – the upper limits of pol-lutant emissions into the environment). ELVs are applied first,through the introduction of best available technology for pointsource pollution, or best environmental practice for diffuse pollu-tion. If this is not enough to reach EQSs, more stringent ELVs mustthen be applied in an iterative process. Furthermore, Member Statesshould follow the principle of full cost recovery of water services,ensuring that water pricing policies are in place to “provide ad-equate incentives” for efficient use of water.

Although some aspects of the WFD are specifically adapted tothe European situation, some key principles could usefully beconsidered as a template for other areas of the world. In particu-lar, the principles of ecosystem-based water policy, cost-recov-ery, administrative management at the scale of river basins andstakeholder participation are all elements of integrated watermanagement that could usefully be considered elsewhere. How-ever, the information and scientific knowledge required withinthe Directive are very significant, already posing major challengesto scientists in the European Union (Ledoux and Burgess 2002,Murray et al. 2002). Furthermore, administrative and institutionalreforms needed for successful implementation of the Directivewill involve significant costs in many European countries (Kallisand Butler 2001). This might be a significant barrier towardsimplementation in less-developed countries where administra-tive, institutional and information-gathering costs could be evenhigher. Humphrey et al. (2000) also note that although the newdirective provides an integrated approach to river basins associ-ated to coastal waters, any sustainable coastal management policywould need to take a wider geographical perspective, as physi-cal, ecological and socio-economic influences of and on the costgo further than the narrow strip considered. The new EU com-munication on Integrated Coastal Zone Management: a Strategyfor Europe (COM/00/547 of 17 Sept. 2000) is a step towards amore comprehensive coastal zone management policy.

Fig. TB5.1.1. DPSIR framework and WFD tasks

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cause, a change in the ecosystem, affecting fisheries yieldsnegatively. Thus, the success of regulatory efforts hascaused environmental changes that were not anticipatedby the general public or the fisheries sector.

In terms of major pressures on the coast, contami-nants and industrialisation received in most cases a lowranking, with the exception of the Russian Arctic wherelarge-scale nuclear industries have caused an input ofradionuclides into rivers and the Arctic seas.

The global inventory of pressures on the coastal sys-tem has clearly shown that many of the drivers are out-side the influence/jurisdiction of the local coastal man-ager; in particular, the economic activities within catch-ments that have a pronounced influence on the coast. Theregulatory frameworks the coastal manager has to im-plement are rarely related to the regulatory frameworksthat exist at the catchment level. The “airshed” also needsto be taken into account as atmospheric deposition is amore important input of nutrients and pollutants thanin the past and crosses different boundaries than doesthe watershed. There is clearly a mismatch between theseregulations and the scientific approach, which considersthe catchment and the coast as a continuum.

Other examples of pressures outside the realm of thecoastal manager’s responsibility include those related totransport (shipping), for example, the introduction ofexotic species and the use of toxic chemicals for anti-fouling on ships. Regulatory measures in these cases haveto be taken at the global level.

Clearly outside the sphere of influence of the localmanager are the effects of global change, such as sea-level rise and increased frequency of storm events. Inaddition, global change affects the catchments throughalteration of the hydrological regime, migration of popu-lation and changing patterns in global trade, which inturn affect the nature of economic activities in the coastalzone and in the catchment.

5.3.3 Material Fluxes

The dynamic processes acting on coastal zones are im-pacted by human influences acting on upland water re-sources and changing the timing, flux, and dispersal ofwater, sediments and nutrients. These influences include:

� Changes in the timing of when water is transportedto the coast by reservoirs constructed for electricalpower generation and flood mitigation, or entire wa-ter diversion schemes.

� Changes in the amount of water transported to thecoast due to water use for urban development, indus-try and agriculture.

� Regional decreases in the delivery of sediment to somecoasts resulting from trapping within reservoirs, bar-rages and other water and erosion control structures.

� Regional increases in the delivery of sediment to somecoasts resulting from increased soil erosion associ-ated with agriculture, construction (urban develop-ment, roadways), mining and forestry operations.

� Changes to the flux rates and loading of nutrients tothe coast (e.g., from storing of carbon in sediments ofreservoirs, elevated nitrogen fluxes from agriculturalactivities).

The consequences of these human impacts on theEarth’s coastal zones are:

� loss of ecosystem health and diversity;� reduced vitality of coastal wetlands, mangroves, sea-

grass beds and reefs;� reduced production of renewable resources, includ-

ing environmental services;� impacts on coastal stability, biostability and shoreline

modification;� changed residence time of contaminants and changed

sediment grain size; and� changes to the dispersal area and plume intensity of

particulate loads from rivers.

5.3.3.1 Impacts of Local, Regional and GlobalSea-level Fluctuations

The last decade has seen an increase in the accuracy ofglobal sea-level measurement with new techniques (e.g.,satellite altimetry and geodetic levelling). The historicrecord of sea-level change interpreted from tide-gaugedata shows that the average rate of sea-level rise wasgreater in the 20th century than in the 19th century. Theraw tide gauge data need to be corrected for local andregional influences either with modelling calculations ordirectly by geological investigations near tide-gauge sites.The estimated mean sea-level rise based on tide-gaugerecords for the 20th century have been in the range of1–2 mm yr–1 with a central median value of 1.5 mm yr–1.

Current scientific projections of sea-level rise arewithin a range of 0.09 to 0.88 m for the period 1990 to2100 with a central value of 0.48 m. The projections couldvary by as much as –0.21 to +0.11 m if current rates ofterrestrial storage of sediments continue. Irrespective ofthe local variability resulting from the interaction of sedi-ment supply and coastal erosion processes, achievementof an average sea-level rise of 0.48 m by 2100 would re-quire a greatly accelerated rate (2.2 to 4.4 times) in sea-level rise compared to that of the 20th century.

There is still a need for better information on localand regional sea-level change and more accurate predic-tion of their impacts. An important element of sea-levelchange research is the need to improve prediction ofimpacts on different types of coast, such as rocky coasts,sandy coasts, deltaic coasts, tropical coasts and low lati-

5.3 · Key Findings


tude coasts. Many of these are already eroding (e.g., sandycoasts), but new threats are appearing in areas such asthe Arctic coast, where changes in the extent of sea-icehave in places produced a different wave climate and con-sequent coastal impacts.

It is equally important to place present and predictedsea-level changes into their geological context in orderto provide a perspective on the cyclical nature of sea leveland the extent to which present and predicted changesare perturbations from natural cycles, particularly the100 000 year glacial/interglacial cycles. The geologicalrecord also shows that there has been a globally variablebut predictable coastal response to the sea-level rise fol-lowing the last glacial maximum. In addition, recent geo-logical research shows prospects of linking geologicallyrecent records of the last 2 000 years with sea-surfacetemperatures and regional climate change.

Our ability to assess the scale and rate of change tocoastal systems associated with relative sea-level rise islimited, and there is a need to refine and upscale regionalvulnerability assessments. Improvement to our ability toconduct such assessments will enhance decision-mak-ing concerning an appropriate combination of the threeoptions for intervention: retreat, accommodate or protect.

5.3.3.2 Sediment Flux to the Coast

The sediment load delivered by the Earth’s rivers has amajor influence on the dynamics of coastal change. Oceanenergy (tides, waves, currents) reworks river-suppliedcoastal sediment to form and maintain our varied coast-lines: estuaries, beaches and deltas. If the sediment sup-ply from the land is reduced, then ocean energy will be-gin to relentlessly attack and erode shores, driving thecoastline inland.

Climatic shifts are often the major factor driving sedi-ment flux. Large continents are influenced by a numberof climatic phenomena operating over different timeperiods. Individual regions may respond quite differentlyto climate forcing, which will depend on the duration ofthe climate fluctuation and the variability in spatial prop-erties of such parameters as relief, geology and hydro-logical processes. As one example, an increase in the fre-quency and intensity of El Niño events will increase thesupply of sediment to local coastal areas at a sub-globalscale – in different hemispheres and different continents.

Human activities have substantially increased the con-tinental flux of sediment during the last two millenniafrom changes in:

� land-use practices that have increased soil erosion (e.g.,agriculture, deforestation, industrialisation, mining),

� practices that have decreased soil erosion, includingengineering of waterways, and

� the trapping and retention of sediment by reservoirsand rivers.

Most of the sediment eroded off the land remains storedbetween the uplands and the sea. Retention of sediment inlarge reservoirs constructed during the last 50 years hasdecreased the global flux of sediment to the coastal zoneby 30%. This is likely to be exacerbated by the increaseddevelopment of small impoundments at the farm scale,as management responses for erosion control and mat-ter storage (Smith et al. 2001). Because lower sedimentloads are reaching the coast, shoreline erosion is acceler-ated and coastal ecosystems deteriorate with a corre-sponding change (including reduction) in local fisheriesyields. The coupling of increased nutrient inputs anddecreased sediment loads (e.g., the Nile which is now nu-trient-enriched due to fertilisers and wastewater althoughsediment loads are reduced because of the Aswam dam)may promote coastal-zone eutrophication and hypoxia.

5.3.3.3 Dynamics at the Estuarine Interface

The amount of sediment in motion and the length of timeit is retained in coastal systems such as estuaries and del-tas is unknown. Geomorphic processes are the most impor-tant single factor controlling the residence time for sedi-ments in the coastal zone. The interactions between geo-morphology and advective processes are non-linear, mak-ing the prediction of the fate of sediment input into coastalareas difficult, across both short and long time-periods.

In many countries in the wet tropics intense rainfall,coupled with deforestation, land clearing, overgrazingand other poor farming practices, has considerably in-creased soil erosion and sediment flux. For tropical estu-aries and coastal seas, environmental degradation dueto increased sedimentation and reduced water clarity isa serious problem.

In contrast, developed countries in mid-latitudes haveestuaries that are generally suffering from sediment star-vation due to extensive damming and river-flow regula-tion. Sediment retention by dams leads to acceleratedcoastal recession (e.g., deltas of the Colorado, Nile, Ebro,Mississippi and Volta rivers; Text Box 4.10), as will soonbe the case for the Yangtze River in China. Water diver-sion schemes also accelerate coastal erosion.

5.3.3.4 Groundwater Inputs

Subterranean and sub-seafloor fluid flows in the coastalzone have a significant influence on sediment and nutri-ent fluxes, and can be a source of biogeochemically im-portant constituents including nitrogen, carbon andradionuclides. If derived from land, such fluids provide

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a pathway for new material fluxes to the coastal zone andmay result in diffuse pollution in regions where ground-water is contaminated.

5.3.3.5 Management Implications

Greater attention should be given to the contribution ofhuman activities and natural processes acting on catch-ments and the resulting fluxes of energy, water and sedi-ment reaching coasts. Reduction of sediment inputs tocoastal systems combined with relative sea-level rise willincrease the vulnerability of coastal areas, together withassociated human activities and corresponding privateand public investment, to natural hazards such as flood-ing, storm over-wash, erosion and salinisation of surfaceand ground waters. In many humid regions, increasedintensity and periodicity of surface water flows and ratesof soil erosion can lead to accelerating risks of riverineflooding, rapid accretion of coastlines and degradationof coastal systems through siltation. Human-inducedchanges to material and energy fluxes will also have anadverse influence on primary and secondary biologicalproduction and the ability of coastal ecosystems to sus-tain demands for renewable natural resources.

Given the high rates of sediment retention associatedwith the damming of rivers and flood control structuresand the corresponding negative effects on coastal systems,thought should be given to the managed release of trappedsediments to help achieve a better balance between ero-sion and accretion processes within estuarine-nearshorecoastal systems. Conversely, increased soil conservation andreduction of sediment loads in humid regions may help toreduce the negative effects of increased siltation rates.

A distinction should be made between natural coastalvulnerability and vulnerability of human lives and prop-erty that may be at risk from the effects of climate change,changes in the sedimentary budgets of coastal systemsand sea-level rise. In many cases, poor coastal planningresults in the need for rapid and expensive adjustmentto the consequences of sea-level change. However, thereis a need for a better understanding of local sea-levelchange, in addition to adopting a precautionary ap-proach, in planning for the consequences of the predictedglobal sea-level rise.

Greater attention should also focus on groundwaterinputs to coastal systems. Groundwaters typically havehigher concentrations of dissolved solids than most ter-restrial surface waters. Submarine groundwater discharge(SGD) often makes a disproportionately large contribu-tion to the flux of dissolved constituents, including nu-trients and pollutants. In addition, discharging ground-water interacts with and influences the recirculation ofseawater, which can affect coastal water quality and nu-trient supplies to nearshore benthic habitats, coastal

wetlands and breeding and nesting grounds. One of themore important implications for coastal zone managersis nutrient (or other solute) loading to nearshore waters.Amelioration of impacts in the coastal zone from theseinputs could be the basis for improved land-use plan-ning and may place limits on development.

Managers should have increased awareness of the rela-tive relationships and priorities of SGD among the mul-tiple factors considered in coastal management activi-ties. This requires modifications in the current ap-proaches for studying groundwater discharge so that:

� The scale of emphasis becomes that of managementareas – probably tens to hundreds of kilometres. Cur-rently, scientists are typically performing investiga-tions at the lower end of this scale (although sometracer investigations work at scales of 10–100 km).

� Scientists may study one area for years, often reflect-ing the typical 2–3 year grant cycle. Managers, on theother hand, will have need for relatively simple andrapid diagnostic and assessment tools to evaluate lo-cal importance and management issues related to SGDin specific settings. The concerns could be either natu-ral processes or human activities.

5.3.4 Biogeochemical Budgets

The LOICZ biogeochemical budgeting effort updated theestimates of dissolved inorganic nutrient (N, P) loadingto the ocean, including revised estimates for geographicdistribution of that loading and the load response to hu-man population and runoff. These estimates are substan-tially higher than those of Meybeck (1982) and some-what elevated above the estimates by Meybeck and Ragu(1997), as shown in Chap. 3. Also, the new estimates con-tain values for inorganic nutrient load to the ocean un-der “pristine” or pre-human impact conditions. Whiledirect updates of dissolved organic nutrients or particu-late nutrients are not provided, the following generalobservations can be made:

� globally, inorganic nutrient loads seem likely to havechanged the most; this is consistent with earlier esti-mates by Meybeck and others; and

� although it might be expected that greatly elevatederosion would have increased particulate nutrient de-livery to the ocean (based on analyses of the USA;Smith et al. 2001), this seems not to be the case forparticulate material in general. Apparently most par-ticulate erosion products have been retained in riverchannels and impoundments.

It can be argued that the changed inorganic nutrientloading has little impact at a continental shelf scale.

5.3 · Key Findings


respectively, indicates that the coastal ocean is substan-tially more heterotrophic (production/respiration ra-tio = 0.97) than the open ocean (p/r = 0.998). In the sec-ond place, the apparently slight net heterotrophy of theglobal ocean (p/r = 0.994; [p – r] = –23 × 1012 mol yr–1) isan important part of understanding oceanic function andlinkage to the slightly autotrophic land. However, this netheterotrophy is quantitatively insignificant in the oce-anic role as a sink for anthropogenically generated CO2.That sink strength is about 10 times the source strength ofnet oceanic heterotrophy and is (globally, on the 150-yeartime scale over which humans have significantly perturbedthis flux) dominated by atmospheric partial pressure andthe physical chemistry of seawater. Clearly, on longertime-scales the so-called biological pump and continen-tal shelf pump are influenced by biogeochemical proc-esses in both the open ocean and the coastal ocean.

5.4 Now and into the Future

The inter-relationships among the thematic studies de-scribed above can be simplified as follows:

� Material fluxes of water and sediment are the vectorsfor the nutrients and carbon, and the controls on theexchange times determine the nature and productsof the biogeochemical “reactors” formed by estuariesand coastal systems.

� These fluxes are controlled by the natural features oflandscape and climate, but are substantially modifiedby human activities – the focus of the LOICZ-Basinseffort.

� Ultimately, more accurate quantification and up-scal-ing of coastal biogeochemical processes, as well asprediction or management of possible changes bothregionally and globally, will involve merging the dis-parate understandings of the fluxes and their naturaland socio-economic controls.

� The coastal budget systems are the natural commonfocus of these efforts, as shown by initial successes indescribing nutrient loads to the coastal zone as func-tions of runoff and population and by the difficultyof predicting the effects of these loads on coastal sys-tems, both in specific regions and globally.

An illustrative example of integrative linkages betweencomponents of LOICZ research is the coupling of land-ocean interactions between specific types of terrestrialbasins and coastal configurations. An observation emerg-ing from the biogeochemical budget studies, supportedby findings from the material flux studies, is that thereare qualitative differences between the functioning oflarge and small coastal systems and, similarly, betweenthe large and small drainage basins that discharge their

This is based on the loading for the ocean as a whole,where cycling between the deep ocean and surface ocean(for both N and P) and between the surface ocean andthe atmosphere (for N) are far larger than can be ac-counted for by the nutrient load from land. This suggeststhat, apart from some small but significant fraction ofthese internal cycling exchanges between the continen-tal margin and the open shelves, the terrestrial load gen-erally is probably not significant at the scale of the conti-nental shelves, excepting some specific examples, suchas Mississippi River and adjacent continental shelf.

This does not imply that the terrestrial load is notimportant or that shelf cycling is not important in theglobal ocean nutrient cycles. Rather, the argument is thatthe importance of the shelf is largely felt at a local scale,especially in bays, estuaries and inner shelves. Thesesmall-scale features are the “first line of defence” againstthe delivery of products to the ocean – under both pris-tine and Anthropocene conditions. Particulate materialstend to sediment near the sites of their delivery to theocean, and reactive dissolved inorganic materials tendto react there. Some dissolved nutrients, however, maybe taken up and regenerated several times close to thesource or at much greater distances following dispersalby currents. The strong negative log-log relationshipsseen between the absolute rates of the non-conservativefluxes and either system size or system exchange timeargue that the most rapid rates of net material process-ing occur inshore. Integration of either the “raw” non-conservative fluxes of ∆DIP and ∆DIN or the derivedfluxes of [p – r] and [nfix – denit] suggests that theserapid, small-system inshore fluxes dominate global shelffluxes i.e., size matters. Internal cycling exchanges withinestuaries and nearshore marine areas are thus very im-portant with respect to river basin and coastal zone man-agement.

The scale of analysis used in the LOICZ biogeochemi-cal approach confirms our previous understanding of thecoastal zone as a source or sink of CO2 (see Smith andHollibaugh 1993). More organic matter is delivered to theocean than is buried there. About half of the organicmatter delivered to the ocean is particulate, and most ofthat apparently sediments near the point of delivery.Some dissolved organic matter apparently reacts withparticles and probably also settles in the nearshore re-gion. Other dissolved organic matter does not have thisfate; it is apparently decomposed via a combination ofphoto-oxidation and microbial processes. More than halfof the organic matter delivery is oxidized somewhere inthe ocean, with about 7 × 1012 mol yr–1 of net oxidationin the coastal zone and 16 × 1012 mol yr–1 in the open ocean.

There are, however, two aspects of this analysis of car-bon flux that bear elaboration. In the first place, compari-son of estimated coastal and open ocean net primary pro-duction estimates of 500 × 1012 and 3 000× 1012 mol yr–1,

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fluxes to the reactive inner-shelf zone of the coast. Large-basin fluxes, although quantitatively dominant on a cu-mulative global scale, directly influence only a minor partof the length of the world coastline.

In addition, there is a similar socio-economic/humandimension dichotomy between the large and small ba-sins. Coastlines that have catchments that are compactenough for social and economic interaction between thenearshore and the more inland inhabitants (so that theentire unit is likely to be contained within the same na-tional or sub-national political or administrative juris-diction), present qualitatively different needs and oppor-tunities for coastal zone management compared to thosewhere the coast and the hinterland are socio-economi-cally or politically decoupled. Since the former arguablyaccount for more of the coastline, it is important that thevisibility of the larger basins is not allowed to divert at-tention from the quantitative coastal importance of thedistinctive smaller catchments.

Another conceptually integrative factor is the issue ofcoastal exposure and complexity. In Fig. 5.2, red boxesindicate some of the regions where river basins (large orsmall) discharge into waters that are protected from di-rect or rapid exchange with the open ocean by barrierislands or deep, complex estuaries and embayments.These environments strongly condition the fluxes ofwater and sediment in the marine environment that arereflected in the exchange, or residence, time – shownabove to be one of the important characteristics of thecoastal biogeochemical “reactor” system.

5.4.1 River Basin Factors

New institutional arrangements will be required for thecoastal zone to foster inter-sectoral cooperation, coordi-nation and eventual integration of policy, investment,plans and management arrangements to make full useof the results of the emerging scientific knowledge. Thesecan help to improve the sustainability of use of coastalareas and resources while avoiding increased vulnerabil-ity in such uses to natural hazards. Development of par-ticipatory partnerships between the natural and socialsciences and the users of scientific knowledge will becritical to future progress from both a scientific and amanagement standpoint. Consideration of drivers andpressures requires exploration of the differences in per-ceptions held by various groups of stakeholders. Oftencultural differences lead to separate perceptions of coastalvalues and hence the “acceptable” or “consensus” man-agement options will require a regional-historical per-spective.

The impact of local civil strife and warfare on thecoastal system is often insufficiently addressed or un-known. Examples where impacts have been observed are

in the Arabian Gulf (after the first Gulf war) and in Ni-geria, both cases involving major oil pollution. Delaytimes between changes and the impact of drivers andpressures, and the potential for a non-linear response ofthe coastal system (e.g., geomorphologic change, ecosys-tem change) are recognised, but quantitative informa-tion to allow predictive modelling is lacking.

5.4.2 Material Fluxes

A major finding of the LOICZ research is that the influ-ence of humans and/or climate affects smaller river ba-sins more dramatically than larger river basins, due tothe modulating capacity of large rivers. Therefore, newtechniques must be developed to address the coastal re-sponse in these sensitive smaller systems. Scaling tech-niques must also be employed to address the quality andusefulness of our global databases, since:

1. most of the observational data was determined acrossonly a few years (and intra-annual variability can ex-ceed inter-annual variability by an order-of-magni-tude), and

2. observational data sets are already a few decades oldduring a time of rapid change resulting from humanimpact. Information on groundwater is a case in point.

Additional data collection describing groundwaterdynamics is required in many areas, especially in SouthAmerica, Africa and southern Asia, where, to our knowl-edge, no assessments are currently available in the lit-erature. We recommend an approach that targets repre-sentative types of coastal aquifers based on geology (e.g.,karst, coastal plains, deltaic) and environmental param-eters (e.g., precipitation, temperature). The productionof a SGD database and globalisation efforts are neces-sary to understand controls and changes in SGD on broadsub-regional and continental scales.

Improvements must also be made to techniques usedfor measurements of SGD, including: the developmentof new non-invasive methods, measuring and samplingstrategies in permeable sea beds, modelling of the dif-ferent transport processes and their effects on biogeo-chemical cycles and the development of new dynamicmodels to explain the porewater flow observed in natu-ral environments.

Management of SGD in coastal areas requires greatlyimproved knowledge about the importance of hydrologi-cal flows. Since SGD is essentially “invisible,” the prob-lem that arises from both a management and scientificstandpoint is determining how to avoid the error of ig-noring an important process or wasting valuable re-sources on an unimportant issue. Where SGD is a sig-nificant factor in maintaining or altering coastal ecosys-

5.4 · Now and into the Future


tems (terrestrial, estuarine or marine), coastal zone man-agers will need to consider management of water levelsand fluxes through controls on withdrawal or alterationsin recharge patterns, as well as groundwater quality man-agement (e.g., through controls on land use and wastedisposal). Such major interventions require a sound sci-entific justification and technical understanding thatdoes not currently exist.

5.4.3 Biogeochemical Budgets

A major challenge in enhancing scientific knowledge andits use for informing management is the issue of spatialheterogeneity and the choice of appropriate scales to usein analysing biogeochemical processes and budgets. It isobvious that with decreasing system size comes increas-

Fig. 5.2. River basins from the coasts of the US and Central America. The transparent grey is a 100 km buffer around the coastline, indicat-ing the approximate extent of the coastal zone. Yellow basins represent those less than 10 000 km2 in area – the approximate dividing linebetween “small” and “large” basins. In (a), small coastal basins appear numerous, but far from continuous. A close-up view in (b) bringsthe smallest coastal basins into view, and shows how much of the coastline is without the large basin discharges indicated by arrows (e.g.,three in all of peninsular Florida). Similarly, in (c), it can be seen that the isthmus of Central America contains only small basins – a featurecommon to many islands and peninsulas. (d) shows part of the west coast of Mexico and the US; there are only two large basin dischargepoints between the tip of Baja California (not shown) and southern Oregon. Many extensive reaches of coastline are dominated com-pletely by inputs from the functionally distinctive smaller basins

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ing heterogeneity among systems. The ocean as a wholeis a large system in which most metabolism is accom-plished by plankton with relatively rapid biotic turnoverrates. Smaller systems in the coastal zone are locallydominated by plankton, benthic micro- and macroalgae,seagrasses, coral reefs and mangroves. These systemsdiffer greatly between one another, and they respond verydifferently to perturbations. Generalising globally there-fore demands that each system type be adequately rep-resented at an appropriate scale for data analysis.

Several other challenges are associated with methodo-logical issues. The first issue involves scaling. Becauselarge systems tend to have longer water exchange times,this can be considered a scaling issue in both space andtime. Any budget or inventory approach to assessing thefunction of aquatic ecosystems needs to deal with twobroad classes of material transfer: physical transfer andbiotic cycling. As a generality, the physical transfers havea wide dynamic range at small scales. For example, waterflow can vary from near stagnant to meters per second(a range of orders of magnitude). As scales get larger, theaccumulated physical transfers are smaller – large trans-fers in one direction tend to be balanced by transfers inthe other direction. This balance is required to conservemass. At small scales, biotic transfers tend to have a muchlower dynamic range and these processes also tend tobalance at larger scales. However, with an increase in scale,the ability to see small effects of biotic processes grows.More information is needed for small, active systems withshort water exchange times while recognising that thesesystems tend not to yield robust estimates of fluxes.

A second methodological issue concerns the use of∆DIP as a proxy for organic carbon metabolism. Thisclearly works in some – but not all – systems. In particu-lar, other reaction pathways, notably sorption and de-sorption of DIP with respect to sediment particles, in-terfere with the proxy. This is a particular problem forsystems with high mineral turbidity. Yet reliable data sim-ply do not exist to develop a large number of budgets orinventories based on carbon. Either an alternative ap-proach must be found or methods must be developed tomodify the DIP budgets.

A third methodological issue involves extrapolationfrom a relatively small number of budget sites to the glo-bal coastal zone. We have used a powerful geo-statisticalclustering tool (LOICZView) and data available at a gridscale of 0.5 degrees (areas > 2 000 km2 for much of theglobe). This grid scale is largely dictated by the availablespatial data. On land, because most features are both spa-tially fixed and readily visible, global resolution to 1 kmis available for many variables. In the ocean, resolutionof geo-spatial data is hampered by the more rapid dy-namics of water movement, the limited ability to see andthus describe subsurface features, and the importance oflargely invisible chemical characteristics of the water.Most available spatially distributed information is at

scales well in excess of 1 degree and interpolated to smallerscales. It is therefore impossible to use such coarsely de-fined data to extrapolate the characteristics of small coastalfeatures. Some alternative approach must be found.

Successful extrapolation from the LOICZ biogeo-chemical budget data to the global coastal zone requiresthree classes of globally available data:

� data for that portion of the land delivering materialsto a particular location (system or biogeochemicalbudget site) in the coastal zone,

� oceanic data adjacent to the system, and� oceanic data for that system.

For land, data can be obtained from highly resolvedremote sensing data. These data can be re-sampled at thescale of the budget system watershed, or catchment, i.e.,at a more natural or functional scale than the 0.5 degreegrid. Process-based regression models of material fluxescould then be developed for the budget catchments andthen extrapolated to the generally coarser and more ar-tificial catchments defined by the 0.5 degree grid. Boththe lack of an objective oceanic functional unit equiva-lent to catchment basins and the crudeness of the oce-anic data have so far precluded an equivalent analysisfor either the budget systems themselves or the oceanregion exchanging with any particular system.

It is clear that there are subject areas that deserve fur-ther research and assessment based on collective expe-rience gained by LOICZ. The first area concerns themesand methodological issues, which represent possible re-visions or expansions of the LOICZ fundamentals. Addi-tional issues concern the refinement of LOICZ softwaretools and support. Other possible gaps are (1) lack of largeriver budgets, treatments and actual determination ofproportional influence, and (2) geographic coverage gaps,such as the North American continent including Arctic,the European Arctic and Central America.

5.5 The LOICZ Contribution

Drawing the outcomes of the LOICZ themes together, andconsidering the questions they raise, highlights somebroad key outcomes from the first phase of LOICZ re-garding impacts along the catchment–coast continuum:

1. Land use and cover change, directly or in adaptationto global forcing and related changing societal de-mands for space, food and water, are driving changesof material fluxes through river catchments to the coastalseas and cause state changes and system impacts.

2. Priorities of drivers and trends that can be expectedto generate key coastal issues are urbanisation andincreasing demand for water (river regulation) andfood (agriculture/fertilizer use).

5.5 · The LOICZ Contribution


3. Advancement in mitigating riverine nutrient and con-taminant loads to the coastal zone is being accom-plished in certain areas such as Europe in time-scalesof two decades following policy implementation thattargets specific goals for point-source treatment.

4. Costs of “no-response” scenarios that exceed criticalthresholds of system function and lead to habitat im-pact are evident in some sites and are likely to increase.

5. Most of the global coastal zones affected by river in-put from small and medium-sized catchments arelacking the scientific understanding of catchmentcoast interaction dynamics and scales as well as theinstitutional underpinning to cope with increasingpressures.

6. Small and medium-sized catchments and in particu-lar small and low lying island-dominated areas fre-quently feature the extreme end of DPSI scenarios(e.g., population-density driven water demand andpollution), and there is little evidence for operationalmechanisms to take scientifically based managementaction.

7. Tools and mechanisms to utilize the scientific under-standing are available in some areas and are lackingin others. In particular the institutional dimensionsof either scientific and management response haveproven to be rather ineffective in many regional as-sessments. However, the key prerequisite to improv-ing this situation is to apply a broad, full-catchmentscale to the scientific, assessment and managementaspects to adequately address the temporal and spa-tial complexity of the issues.

8. The overall trend expectation of the driver develop-ment affecting coastal seas indicates an acceleratedcatchment based influence on coastal zones and theirfunctioning.

The key issues identified from the LOICZ work andthe scientific framework that has been developed sup-port evolving concepts of integrated management forterrestrial, coastal and marine systems. For example, theUN sponsored Global Environment Facility (GEF) Op-erational Programme No. 2 gives priority to “the sustain-able use of the biological resources in coastal, marineand freshwater ecosystems.” The European Union devel-oped the Water Framework Directive that required inte-grated management strategies to be developed for riverbasin systems. This has been followed by a Recommen-dation to all Member States to develop integrated poli-cies, management strategies and plans for the implemen-tation of integrated coastal zone management. Theseexamples illustrate the movement towards more inte-grated development planning and resources managementand the corresponding need for enhanced scientificknowledge and frameworks of the kind LOICZ has beendeveloping to help inform policy, management strategiesand planning decisions.

The LOICZ programme also provides an ongoing,adaptive global synthesis that represents an evolving newapproach to linking science and management. It has seve-ral features that allow it to function in this way, including:

� an adaptive approach to science and management,� evolving questions,� long term (ongoing) projects,� a unique global network of participating scientists and

others who have adopted the LOICZ methodologies,and

� ongoing, participatory synthesis to help prioritise fu-ture research needs and goals.

5.6 Implications for Management

The first phase of the LOICZ programme provided a valu-able scientific framework for studying and integrating abroad range of factors that influence the dynamics ofcoastal systems and the human use of the resources de-rived from the functions of those systems. The individualthematic studies presented in the previous chapters haveexpanded our understanding of the transformation andfate of materials discharged into different coastal envi-ronments. While there are constraints imposed by lim-ited understanding of natural variability in climatic con-ditions and the full impact of human-induced changeson water and material fluxes, there is now sufficient un-derstanding of these factors to develop new and more ho-listic frameworks for understanding how coastal ecosys-tems are responding to human pressures and how we canimprove coastal management to respond to these changes.

The key findings of the thematic studies and theirimplications for management are:

� Coastal systems are important to the functioning ofthe Earth system.

Although the coastal zone is only 12% of the surfacearea of the Earth, coastal systems have been shown tobe disproportionately important in the global cycles ofnitrogen, phosphorus, and carbon. At local to regionalscales, waste and load estimates have been derived, sys-tem metabolism has been estimated and tools and a database of more than 200 coastal sites have been developedand made accessible through a dedicated public website(http://data.ecology.su.se/MNODE). Estimates of humanpressures on material fluxes and changes in river catch-ments affecting the coastal seas have been derived atthe continental scale for Africa and South America, atthe sub-continental scale for Europe and Asia, and forsmall-island areas of the Caribbean and Oceania. Dataand the resulting information and synthesis have beenmade publicly available (http://w3g.gkss.de/projects/loicz_basins). The improved management of humanactivities affecting material fluxes to and within coastal

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systems could therefore play a significant role in man-aging global material cycles and moderating the influ-ence of climate change.

� Investing in science and management of the coastalzone is highly worthwhile.

Coastal ecosystems are complex, productive andcritical to human society, and are impacted differen-tially by human activities. LOICZ identified and quan-tified the vulnerability of coastal systems to globalchange impacts. Differences between un-impactedand impacted coastal ecosystems can be significantand can dramatically affect the provision of ecosys-tem services that support human welfare. The valueof ecosystem services derived from the coastal zoneis estimated to be large (US$ 17.5 trillion yr–1) and un-der significant threat. A more certain scientific un-derstanding of coastal processes can help to improvethe management of coastal systems, reduce the vul-nerability of human activities and enhance the sus-tainability of public and private investments. There-fore, investing in science and management of thecoastal zone makes good economic sense.

� A broad systems approach is necessary to effectivelymanage human activities in the coastal zone.

The coastal zone is dynamic at multiple time andspace scales, but it is possible (at least to some de-gree) to separate the background “natural” dynamicsfrom changes due to human activities. Resilience andadaptability to change at various rates in the biologi-cal and social components of the system are criticalto their sustainability. To understand these impactsand to manage effectively the human activities in thesesystems, we need to adopt a broader “systems” per-spective that integrates the interacting biophysical andsocial dynamics and the multiple temporal and spa-tial scales involved. To meet some of these needs, atypology system of the coastal zone was developed.Application of this approach also allowed us to un-derstand the previously under-estimated influence ofgroundwater discharge on coastal systems.

� Complex scientific information can be synthesized toinform and improve the management of coastal systems.

Synthesising the large and complex amount of dataavailable about the coastal zone to address manage-ment issues is a daunting task that often hinders ef-fective management. The DPSIR approach is a usefulframework for enhancing stakeholder participationand organizing and synthesising knowledge aboutland-based fluxes and other information importantto management of the coastal zone at regional andlocal scales. Regional/continental scale assessmentsare a useful complement to the DPSIR approach. Theregional river-basin studies have identified a commonlist of drivers for river basins and have identified keydifferences in the relative importance of these driversamong regions. For example, the major influence

(driver) in temperate climatic zones characterized byindustrial development and urbanisation is eutrophi-cation of estuarine and nearshore marine waters. Fortropical river basins the main driver for coastal changeis change in sediment budgets. For polar climatic zones,the main driver of change is change in climatic con-ditions. Therefore, the focus of management in eacharea needs to correspond to what are found to be themajor drivers and influences. The DPSIR approach isalso iterative, so that as the relative importance of spe-cific drivers changes with time, these “new” conditionscan be fed back into the cycle for re-analysis.

Although there are major river systems discharg-ing into the coastal zone, most of Earth’s coastline ischaracterized by small heterogeneous systems thatcontribute disproportionately to carbon and nutrientbudgets and have high potential to be influenced byhuman activities. Therefore, management to mitigatethe impacts of human activities on small, semi-en-closed systems, as well as on large catchment systems,is an important objective.

5.7 The Future of LOICZ

The science of LOICZ has focussed on the measurementof biogeochemical fluxes into and within the coastal zoneand shown these fluxes to be important and relevant toglobal environmental change (GEC) science because:

� biogeochemical fluxes of CO2 and trace gases are thekey variables for scaling up to global climate change,

� biogeochemical variables are the key constituents forconnections across coastal boundaries i.e. from catch-ment to coast, from coast to ocean and from coast toatmosphere,

� biogeochemical fluxes include primary production,which underpins ecosystems and renewable resources,

� water and sediment quality determine distribution ofkey habitats and affect human amenity and use, and

� biogeochemical processes and cycles include key posi-tive and negative feedbacks in coupled coastal systems,which determine thresholds and boundaries for sys-tem resilience.

5.7.1 The Future Challenges for LOICZ

From an initial investigation of process and of specificmarine and terrestrial systems, LOICZ has arrived at apoint of improved systematic understanding of the con-trols and influences on coastal fluxes. We can now lookforward to the next steps to inter-calibrate and combinethe results of the converging threads of understandingdeveloped during the first phase of LOICZ. The recom-mendations below reflect the need and opportunities for

5.7 · The Future of LOICZ


advancing the process, recognising the multiplicity ofprocesses, changes and forces (natural and human-driven) across the dynamic and heterogeneous globalcoastal zone.

1. Integrated and multidisciplinary team approaches.While often stated, there is imperative for genuine re-search collaboration among natural, social and eco-nomic disciplines. Existing global examples show clearknowledge benefits from such team interactions. Newapproaches are needed to assist team actions, such asthe DPSIR framework, and “wiring diagrams” used inIGBP for the development of cross-cutting projects.

2. Targeted research. Thematic and programmatic re-search approaches as practised in “post-Normal” sci-ence (Funtowicz and Ravetz 1992, 1993, Ravetz andFuntowicz 1999) address the management of complexscience-related issues by focusing on aspects of prob-lem-solving that tend to be neglected in traditionalaccounts of scientific practice: uncertainty, value-load-ing and a plurality of legitimate perspectives. It pro-vides a coherent explanation of the need for greaterparticipation in science-policy processes, based on thenew tasks of quality assurance in these problem-ar-eas, and is an alternative approach to coastal zone re-search compared with the traditional, fragmentedapproach of task-based, disciplinary or sectoral ef-forts. Questions of different temporal and spatialscales need urgent consideration along with new toolsfor assessment and measurement across scales andwithin socio-economic research. A focus should beplaced on understanding whole ecosystem function-ing and forcing, vulnerability and risk, changing pres-sures, feedbacks and integration of forcings. Improvedmodels (conceptual, numeric, deterministic, probabi-listic) for top-down and bottom-up approaches arerequired. Efforts on socio-economic research need tobe greatly increased.

3. Synthesis and integration of information. New scien-tific enterprise is always welcome but better use needsto be made of existing data, information and knowl-edge; bodies funding research need to shift policiesin this regard. New tools, approaches and effortsshould be exerted for the synthesis of scientific datainto information and knowledge, and outcomes needto be made accessible to users and the community.Along with further concerted effort to engage withusers, science programmes should include a clearstrategy for communication and delivery of informa-tion.

4. Regionality. Thematic projects, synthesis and integra-tion should be directed to assessment at regional scalesto more fully understand the tapestry of the coastalzone and to resolve response and management op-tions that address the vital transboundary elements.

The application of common methodologies will increaseregional integration of information and options.

5. Non-linearity of processes (feedbacks and thresholds).The non-linear relationships of forcing and functionare apparent in the coastal zone. New concepts, toolsand approaches are required, to encompass non-lin-earity in modelling and predictions, scenario-build-ing and vulnerability-risk assessments.

6. Monitoring and indicators of functions and changes.Proxies for measurement of processes and variability,and indicators of system function and response, arerequired to better understand and measure changeand the effectiveness of management and policy ap-plications.

7. Improved databases and access. There is need for con-certed efforts to develop stronger datasets, to fill criti-cal data gaps and to improve cross-referencing of data-sets so that stronger integration can be achieved. Im-proved access to existing data and wider accessible todatasets would reduce duplication in coastal assess-ments.

8. Capacity building. Underpinning future research enter-prise is the need for continuing and enhanced capac-ity-building in both science and management trainingand awareness.

Therefore, the challenges for future GEC research onthe coastal zone are to develop understanding and toolsfor the derivation, differentiation and quantification ofanthropogenic drivers and global environmental pres-sures. This distinction is essential to determine appro-priate management options for land-ocean interactionsin the coastal zone. Consequently, future research goals forLOICZ are aimed to overcome traditional disciplinaryfragmentation, in particular between natural and human-dimension sciences, in order to focus on the primary is-sues of sustainable human use of coastal systems in re-spect to vulnerability of coasts and risks for human uses.

5.7.2 The Potential for LOICZ to Contribute toFuture Coastal Management Challenges

The coastal regions of the globe will form the focus offuture growth of population, development of settlements,and expansion and diversification of economic activi-ties. Coastal regions already provide a significant pro-portion of the goods and services that support the liveli-hoods of coastal communities and national economies.These development pressures will bring major changesto coastal ecosystems and the role they play in globalenvironmental change. There will also be increased risksto human societies from natural and man-induced natu-ral hazards. These risks can be minimised through soundplanning and management of development processes.

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The LOICZ programme has provided a wealth of in-formation that could be used to strengthen the concep-tual basis for integrated coastal management and asso-ciated development and spatial planning. For example,the work on material fluxes and river basins has demon-strated strong linkages between the management of smallto medium sized catchments and impacts on coastal andnearshore marine systems, the supply of natural re-sources they sustain, and functions such as buffering ofstorm surges. The DPSIR framework has demonstratedhow such complex information from the natural and so-cial sciences can be integrated to identify the core driv-ers that influence the management of river systems andthe response of coastal systems. This work could be usedto expand the conceptual basis of existing policy instru-ments, for instance, the EU Water Framework Directive,to encompass material fluxes, surface and ground waterflows, and energy and other factors that will influencesustainable human use of coastal areas. This wouldstrengthen such policy and management instruments bysupporting the development of integrated river basinmanagement and their effectiveness in supporting themanagement of coastal and marine areas.

The challenge is to make available the results of theLOICZ science in a format and constitution that providesa means and route to contribute to the formulation andimplementation of policies, management strategies andimplementation arrangements that are appropriate to thedifferent regions of the world. Although further researchis needed to refine the results of the thematic studies andto strengthen their utility, there is sufficient understand-ing of the role of coastal systems in global environmen-tal change to develop a constructive dialogue with policyma-kers, planners and managers. That is a question ofeffective communication of science and one that the nextphase of the LOICZ programme will address with greatvigour.

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Coastal Fluxes in the Anthropocene: Chapter 5 - Synthesis of main findings and conclusions

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