MARINE AND COASTAL LITTER ON THE LIZARD PENINSULA, CORNWALL - AN ASSESSMENT OF THE PROBLEM AND EVALUATION OF A POTENTIAL LONG-TERM MONITORING APPROACH

1

MARINE AND COASTAL LITTER ON THE LIZARD

PENINSULA, CORNWALL

– AN ASSESSMENT OF THE PROBLEM AND

EVALUATION OF A POTENTIAL LONG-TERM

MONITORING APPROACH

by

Colin Richard Pringle

Thesis presented in part-fulfilment of the degree of Master of Science in accordance

with the regulations of the University of East Anglia

School of Environmental Sciences

University of East Anglia

University Plain Norwich

NR4 7TJ July 2005

© This copy of the dissertation has been supplied on condition that anyone who consults it is understood to recognise that its copyright rests with the author and that no quotation from the dissertation, nor any information derived therefrom, may be published without the author’s prior written consent. This copy of the dissertation is supplied on the understanding that it represents an internal University document and that neither the University nor the author are responsible for the factual or interpretative correctness of the dissertation.

2

Contents Contents.................................................................................................................................... 2 Abstract……………………………………………………………………………………….3 Acknowledgements.................................................................................................................. 4 1. Introduction ......................................................................................................................... 5

1.1 Defining beach litter .........................................................................................................................5 1.2 Sources and amounts of beach litter.................................................................................................5 1.3 Impacts of marine litter.....................................................................................................................6 1.4 Costs of beach litter ..........................................................................................................................6 1.5 Legislation relating to beach litter....................................................................................................6 1.6 Need for beach litter monitoring ......................................................................................................7 1.7 Extent of the beach litter problem ....................................................................................................7 1.8 Beach litter-related aspects of the Lizard Peninsula ........................................................................8 1.9 Methodologies of identifying and sourcing beach litter ..................................................................8 1.10 MCS/BeachWatch survey protocols ..............................................................................................9 1.11 Desirable characteristics of a monitoring approach.......................................................................9 2.1 Intensive beach survey events ........................................................................................................11 2.2 Beach surveys .................................................................................................................................12

3. Results................................................................................................................................. 14 3.1 Summary of full data set results .....................................................................................................14 3.2 Validation of results........................................................................................................................16 3.3 Comparison of beaches surveyed by MCS 2004 and current investigation..................................16 3.4 Impact of litter survey on litter density ..........................................................................................17 3.4.1 Repeatedly surveyed beaches within the current investigation ..................................................18 3.4.2 Impact of surveying on data from beaches surveyed by both the current survey and MCS 2004...............................................................................................................................................................20 3.5 Final data set results........................................................................................................................21 3.5.1 North coast beaches compared with South coast beaches ..........................................................22

4. Discussion of Results ......................................................................................................... 24 4.1 Limitations of collected data ..........................................................................................................24 4.2 Validation of methodology.............................................................................................................25 4.3 Impact of survey on litter density...................................................................................................25 4.4 Characteristics of beach litter in the study area .............................................................................26 4.5 The North and South coasts around the Lizard Peninsula .............................................................27

5. Conclusions ........................................................................................................................ 30 5.1 Data analysis ...................................................................................................................................30 5.2 monitoring approach .......................................................................................................................30 5.3 beach users and SRD ......................................................................................................................30 5.4 Fishing industry debris ...................................................................................................................31 5.5 shipping sourced litter.....................................................................................................................31 5.6 non-sourced litter ............................................................................................................................31 5.7 Survey depletion of litter levels......................................................................................................32

References .............................................................................................................................. 33 Appendix 1: Beach Survey volunteer newsletter .................................................................... 36 Appendix 2: Marine Conservation Society recording and sourcing forms for beach litter surveys..................................................................................................................................... 37 Appendix 3: Map of approximate locations of beaches surveyed ........................................... 38 Appendix 4: Final data set of beach surveys excluding those with preceding surveys carried out within 2 months ................................................................................................................. 39

3

Abstract

Marine and beach litter is a significant issue in the UK, and a relatively greater

problem in the South West region of England. However the extent and composition of

beach litter around the Lizard Peninsula and mid-North Cornwall coast is little known

and poorly monitored at present.

The paper describes an intensive survey of beach litter around the mid-Cornwall

beaches by self-financing volunteer groups, completing 37 beach litter surveys on 18

different beaches during October and November 2004, using the established Marine

Conservation Society survey and litter identification protocols.

The survey results indicate that fishing activity is the major source of beach litter on

the mid-North Cornwall coast, and that efforts in reduction of litter at source should

be focussed on the fishing industry. Non-sourced litter was a major proportion of the

overall litter burden on both the mid-North Cornwall coast and the Lizard peninsula.

More research and effort into identifying the source of litter in this category should be

conducted. Beach users contributed relatively little to the litter burden on both coastal

areas.

A sustainable method of conducting intensive and rigorous monitoring of beach litter

levels is described where paying volunteers, grant funding, training, planning and

survey management can be maintained and repeated on an annual basis. Such an

approach will develop an increasingly valuable body of data that will inform coastal

management activities, litter reduction efforts, and monitor compliance with existing

and imminent legislation.

4

Acknowledgements

Thanks for assistance provided to enable this investigation to succeed are due to (in

alphabetical order):

British Trust for Conservation Volunteers (esp. BTCV Cornwall Director, Ash

Pearson; BTCV Leaders Jason Appleby, Richard Ballantyne, Frances Keeton, Charlie

Kilgour, Andy Middleton, Ian O’Dare and Harvey Skelcher; and the 30 BTCV

volunteers who participated in the 2004 BeachSweeps)

County Environmental Trust Ltd.

English Nature, Cornwall

Environment Agency, Cornwall (esp. Martin Rule)

Gweek National Seal Sanctuary

InteREAM, University of East Anglia (esp. Dr. Alan Bond, Dr. Dick Cobb, Alan

Ovenden)

Kerrier District Council

Marine Conservation Society

Silver Dolphin Marine Conservation Society

5

1. Introduction

1.1 Defining beach litter

Marine or coastal litter is any item appearing on beaches or at sea as a result of human

activity (MCS, 2004). Marine litter originates from many different sources, circulates

through pathways, and accumulates in litter sinks. (NRA, 1994; MaLiTT, 2002).

Beaches are frequently litter sinks, when litter will build up. A beach may be a

pathway, when litter will be moved on by the action of the sea. Only long term

monitoring can establish the true situation for a specific beach. Clearing beach litter

when a beach is either a sink or a pathway is only a temporary solution, as litter will

be continually deposited (see MaLiTT, 2002)

1.2 Sources and amounts of beach litter

Beach litter may be from a local source or brought by sea currents from distant areas

(Velander and Mocogni, 1998) and comes from four main sources: recreational and

tourism related litter; fishing debris; sewage related debris (SRD), and shipping waste

(see MCS, 2005). Globally nearly 80% of the world's marine debris originates from

land sources (Faris & Hart, 1994). However, the shipping traffic and sea currents of

the UK, and of the South West peninsula in particular means that more waste is

derived from marine activities (Jones et al., 2003). Since 1999, the Marine

Conservation Society (MCS) has produced an annual UK Beachwatch report, which

sources beach litter collected by volunteers. Tourism, fishing and sewage related

debris (SRD) have consistently been identified as contributing the greatest proportion

of litter. The SW has more marine-originated waste than the rest of the UK, although

the greater proportion of litter in the region derives from beach users – in densities

higher then elsewhere in England (MCS, 2005). It must be noted that in all major

studies, it has not been possible to attribute the majority of beach litter to a specific

source (see Storrier, 2004).

The vast amount of coast and marine litter already in the environment and being

released daily means that simple cleaning of beaches is ineffective in the long-term

and is best dealt with by stopping it at source (OSPAR, 1995, 2004; MCS, 2005;

6

Donohue, 2003; US Commission on Ocean Policy, 2003). A litter-free beach can

become heavily littered within three months (Garitty & Levings, 1993).

1.3 Impacts of marine litter

Impacts of marine litter on wildlife have been documented around the world e.g. by

tangling, ingestion and smothering (see Pringle, 2005; Storrier, 2004). Floating litter

also provides routes for colonisation by alien species; and the mechanical effects of

beach cleaning can seriously disrupt ecological communities. Marine litter can result

in chemical hazards and human health risks, and can impact fishing and aquaculture

or affect tourism and recreational use (see Pringle, 2005 for a review). Although many

impacts of marine litter are identified, there is very little quantification of these

impacts.

1.4 Costs of beach litter

Extrapolated annual UK costs associated with marine litter have been estimated at

almost £200,000,000 (MaLiTT, 2002) in impacts on tourism, aquaculture, agriculture,

flood defence, seawater abstraction, power generation and navigation but

EXCLUDING ecological impacts & aesthetic intangible costs. Cornwall local

authorities spend approximately £230 000 per annum on cleaning beaches (Karen

Hall, Environmental & Transport Department, Shetland Islands Council, Presentation

at Beach Litter Management Conference, Newquay, Cornwall, 27th March 1998)

1.5 Legislation relating to beach litter

Despite limited quantification of impact, growing concern over marine pollution has

led to national and international legislation to prohibit disposal of litter at sea or on

land where it can reach the marine environment. The International Convention for the

Prevention of Pollution from Ships (1973) (known as MARPOL 73/78) prohibits the

disposal of plastics and other pollutants at sea (see IMO, 2001). In the UK MARPOL

is implemented as requiring all ports, terminals, harbours and marinas to provide

reception facilities for waste. At the end of 2002 the EU Directive on Port Reception

facilities for Ship-generated Waste and Cargo residues (EC2000/59) was

implemented, eliminating illegal dumping of waste at sea. The EC Bathing Water

Directive (76/160/EEC) establishes bathing water standards, and the EU Urban Waste

Water Treatment Directive (97/27/EEC) requires sewage treatment before marine

7

discharge (ENDS, 2002). The Environmental Protection Act (1990) controls littering

from land-based sources; and the Water Framework Directive establishes integrated

improvement of coastal water quality. The proposed EU Marine Conservation

Strategy calls for eliminating illegal marine litter by 2010 (ENDS, 2002). It is

generally accepted that there is inadequate monitoring of coastal waters to measure

compliance with the legislation (see Storrier, 2004).

1.6 Need for beach litter monitoring

It can be seen from the above that marine litter can be presumed to have an adverse

impact (although inadequately understood) and that monitoring of beach litter is

necessary in order to establish the sources of litter for control at source, and for

measuring compliance with relevant requirements.

The following statement of knowledge gaps in marine litter from the UK Marine

Litter Task Team sums up the present situation:

What we do not know about beach litter (from MaLiTT, 2002)

1. We do not know how marine litter affects populations or indeed whole ecosystems.

2. It is difficult to assess the economic damages associated with the impact of litter on

ecological functions.

3. Not enough is known about the long-term effects of persistent breakdown particles.

4. We do not have enough monitoring data to source litter items accurately.

5. We do not know how effective MARPOL is, since there is no monitoring system to

measure any effects of the legislation.

1.7 Extent of the beach litter problem

Litter is one of the most serious issues currently affecting global coastlines (Tudor et

al., 2003). Beach litter in the UK is a significant and growing problem, with litter

density rising by 81.5% since recording began in 1994 (MCS, 2005). The Marine

Conservation Society has consistently recorded the SW peninsula as the region with

the highest beach litter density in England (MCS, 2003, 2004, 2005). Marine litter has

also been noted as problematic in neighbouring sea areas to the Lizard (DEFRA,

2002; Covey & Laffoley, 2002). Other neighbouring sea areas with litter problems

include the Irish Sea (Davenport & Rees, 1993). On the Lizard Peninsula, there is

8

very limited monitoring of beach litter – e.g. with only three of the 50 SW beaches

surveyed in 2004 being on the Lizard coastline (MCS, 2005). Consequently little is

known about the scale or nature of the beach litter problem on the Lizard, although it

is generally perceived as significant, with many community and council initiatives to

clean beaches (Kerrier District Council, Beach Cleaning Section, pers. comm. 9th

September 2004; ASH, 1995)

1.8 Beach litter-related aspects of the Lizard Peninsula

The coastline of the South West has long been recognised as being of outstanding

importance for nature conservation. This is reflected in the number of coastal SSSIs

and the high degree of protection afforded to coastal areas in the planning system

(Jones et al., 2003).

The economy of the Lizard is dominated by tourism (Cornwall County Council, 2003;

Jones et al., 2003). People tend to avoid littered beaches (Rees & Pond, 1995). The

negative impacts of beach litter on tourism and marine recreational activities are

potentially significant, and anecdotal evidence suggests this to be the case (Kerrier

District Council, Beach Cleaning Section, pers. comm. 9th September 2004).

The long relative length of coastline, the proximity of shipping lanes, prevailing ocean

currents and large numbers of beach users all suggest large potential sources of

marine litter around the Lizard. There is a high density of beaches on the Lizard,

which act as sinks and pathways for much of this litter. Therefore the beach litter has

a potentially significant affect on the economy and environment of the Lizard area,

with minimal monitoring in place. The existing MCS limited monitoring depends on

local volunteer groups that do not provide any guarantees of consistent data collection

over a long time period.

1.9 Methodologies of identifying and sourcing beach litter

Although marine litter is recognised as one of the major problems facing world

coastlines (Goldberg, 1995), most methodologies tabulate the material composition of

the litter without addressing the origin of the litter (Tudor & Williams, 2004; Tudor et

al., 2003). Such data is of limited value in evaluating impacts and formulating

management plans. Beach surveys are the most widely used method of monitoring

9

marine litter (Storrier, 2004). Such surveys allow large amounts of data to be

collected at low cost (Rees & Pond, 1995). The use of volunteers in surveys is

commonplace, and provides impartial data with no statistical difference between that

gathered by experience and inexperienced surveyors (Tudor & Williams, 2001). The

numerous methods of survey used make comparison of studies difficult.

1.10 MCS/BeachWatch survey protocols

The Marine Conservation Society (MCS) works through effecting change based on

sound factual evidence, in particular lobbying to reduce production of marine litter at

source. Since 1983, the Society has become a recognised authority on marine and

coastal litter and is regularly consulted by UK Government on a range of marine litter

issues (MCS, 2003, 2004, 2005).

The MCS Beachwatch campaign was launched in 1993 to raise public awareness

about marine pollution and establish an effective database on marine debris on

Britain's beaches (MCS, 2005)

The MCS beach litter survey protocols are well tested (used since 1994) and the data

is used in various monitoring programmes. The Fifth North Sea Conference of

Ministers (2002) endorsed the campaign. The data was used in drawing up the UK

Government Merchant Shipping and Maritime Security Bill 1997, and is used as the

National Benchmark for assessing quantities and sources of UK coastal litter (MCS,

2005). The Environment Agency ‘State of the Environment of England and Wales’

used the MCS data as a baseline average (EA, 1999). The survey protocol is closely

related to EA/NALG protocol (Environment Agency/ National Aquatic Litter Group)

monitoring of aesthetic quality of beaches (EA/NALG, 2000). The survey protocol

has also been used on intensive studies of specific areas e.g. Severn Estuary, Firth of

Forth, South Australian harbours (Tudor & Williams, 2001; Storrier, 2004; Australian

EPA, undated), particularly because the data collected can be related to national

and/or regional existing baseline data.

1.11 Desirable characteristics of a monitoring approach

A good monitoring programme should be reproducible, as simple as is compatible

with valid data collection; and be sustainable in terms of long-term collection of

10

compatible data (WHO, 2000). The MCS beach survey protocol meets these criteria

(MCS, 2005); and in addition has the desirable aspects of producing public-friendly

data (Storrier, 2004); promotes awareness-raising among volunteers (Australia EPC,

undated), and can both contribute to and draw from nationally and regionally relevant

data.

11

2. Description of Methods

2.1 Intensive beach survey events

The British Trust for Conservation Volunteers (BTCV) have run week-long beach-

cleaning events on the Lizard peninsula on an ad hoc basis since 1999 (Ash Pearson,

Director BTCV Cornwall, planning meeting, personal communication, 12th September

2004). These events comprise 10 paying volunteers, with two volunteer BTCV

leaders. Beaches would be visited without a schedule, and litter would be collected

and then removed by the local District Council.

The author arranged with BTCV that these beach-cleaning events should in addition

survey marine litter through a systematic approach as a contribution to developing

coastal environment management planning. In 2004, a series of four such week-long

volunteer surveys were conducted, with training provided by the author for

volunteers, supporting materials supplied by MCS, and complementary workshops on

identification and impacts of marine litter. Each week-long event was referred to as a

Beachsweep, with Beachsweep 1, Beachsweep 2, Beachsweep 3 and Beachsweep 4

being conducted in October and November 2004 (see Table 1 for dates).

The events as organised were financially self-supporting and are hence sustainable as

a long-term monitoring and assessment approach. The volunteers paid for

accommodation and attendance, and a Landfill Tax grant was obtained. A newsletter

was produced for the benefit of the 30 volunteers and as a means of attracting

volunteers for future survey events (see Appendix 1).

All beaches on the Lizard peninsula and adjacent north Cornwall coast were visited

and risk assessments conducted according to BTCV protocols. Beaches identified as

suitable for volunteer access were then submitted for approval by County

Environmental Trust and Kerrier District Council, and the list finalised.

12

2.2 Beach surveys

Beach surveys were conducted according to the well-established protocols of the

MCS, as used on their national BeachWatch and Adopt-a-Beach programmes, where

volunteers use the approach to gather national and regional data (see 1.10 above).

A minimum of 100m of full-width beach is surveyed at low tide (up to high-tide

mark). Volunteers work in pairs, using litter-pickers to place litter in binbags. The

litter is recorded on the established MCS survey form as to its composition and/or

specific identification (See Appendix 2 for example of sourcing and recording form).

Each piece of litter on a measured area of beach is removed and recorded on prepared

data sheets, categorising items according to material type (plastic, rubber, polystyrene,

metal, ceramic, wood, faeces, glass, paper), and usually to exact identity (over 80

categories). Any items that could be directly traced to a country or company were

recorded. Observations of dead, entangled or stranded animals were noted and

relevant authorities informed. Natural debris was not removed.

As much beach was surveyed as was consistent with weather, access, and volunteer

ability. Litter collected was weighed (where feasible), and the number of full bags

counted, in accordance with MCS procedure.

Volunteers received initial training in survey techniques from the author; litter

identification material from MCS, and undertook three workshops during each week-

long Beachsweep on identifying marine litter and its significance.

The beaches visited were selected according to appropriate times for low tide during

daylight hours; suitable weather conditions on the north or south Cornwall coast and

according to the relative ability of the volunteers. Approximately one beach was fully

cleaned and surveyed during a day, with two beaches sometimes being surveyed in

the day. All selected beaches were visited during the course of the four week-long

survey events.

13

The raw data was collated and processed by the author to give measures of number of

litter items per km of beach. Items were categorised according to six likely litter

sources, or as un-sourced according to MCS procedure (see Appendix 2). The source

categories used are:

• Beach visitor litter

• Fishing

• Sewage Related debris

• Shipping

• Fly-tipped

• Medical

• Non-sourced

14

3. Results

3.1 Summary of full data set results

During the period of beach litter collection and survey for this investigation between

8th October and 19th November 2004, a total of 37 beach litter surveys were conducted

on 18 different beaches on the Lizard peninsula and north mid-Cornwall coast (see

Table1). This data was collected from 10.776 km of beach, resulting in 28,222 items

of litter being collected, identified and recorded.

Total items of litter

collected Litter items per

km

No. beach surveys

undertaken Dates of surveys

Beachsweep 1 7184 898 8 8th-15th October 2004

Beachsweep 2 9028 1003 9

15th-22nd October 2004

Beachsweep 3 6952 772.4 9 29th Oct- 5th November 2004 Beachsweep 4 5058 459.8 11 12th-19th November 2004 Totals

28222

37

Table 1: Summary of beach litter survey data collected by four separate volunteer groups on the Lizard Peninsula 2004

Individual beaches, with length of beach surveyed and number of litter items collected

can be seen in Table 2.

15

Total litter items collected (length of beach surveyed in

m) Beachsweep

1 Beachsweep

2 Beachsweep

3 Beachsweep

4 Porthoustock 1306 (150) 484 (150)

Mullion Cove 159 (30) 90 (30)

Poldhu 1273 (140) 1211 (178) 583 (100)

Trevaunance 369 (208) 45 (100) 301 (100)

Chapel Porth 1817 (100) 268 (200) 645 (100)

Coverack 668 (260) 869 (100) 720 (170)

Loe Bar 1215 (640) 631 (894) 447 (890)

Holywell bay 2074 (650) 683 (150) 796 (1120)

Penryn 448 (1140)

Swanpool 1213 (181) 514 (360)

Prisk Cove 462 (430)

Church Cove 340 (185) 980 (230)

Gunwalloe Fishing Cove 1220 (500) 24 (100)

Porthallow 1603 (188) 1575 (188)

Sunny Cove 529 (180) 155 (114) Perranporth 1508 (120) Flushing 251 (100) Penhale 746 (300) Table 2: Beach litter survey data by individual beaches on the Lizard peninsula and North Cornwall Coast 2004

A map indicating the approximate location of the beaches surveyed can be found in

Appendix 3.

16

3.2 Validation of results

The national MCS BeachWatch 2004 surveyed a total of 269 beaches, comprising

145.2 km of beach, with 275, 594 items collected (MCS, 2005).

In the South West region of England, MCS Beachwatch 2004 surveyed 50 beaches,

comprising14.62 km, with 62, 525 items collected

Therefore the number of items collected in the present study represent 10.2% of the

national 2004 survey; and 45% of the survey in SW England. This represents a

proportionately large data set.

Direct comparison of the total data set is not possible as only three beaches were

surveyed by both the current investigation and BeachWatch 2004 (Church Cove,

Gunwalloe Fishing Cove, and Poldhu Cove)

3.3 Comparison of beaches surveyed by MCS 2004 and current investigation

Litter data for beaches surveyed by both MCS and the current investigation in 2004

are summarised in Table 3. Spearman Rank correlation applied to the ranking of the

percentage contribution of litter sources for the total litter collected for the paired data

on each beach gives significant positive correlation for all three beaches (Church

Cove Corr.= 0.896; Gunwalloe Fishing Cove Corr. = 0.883; Poldhu Cove Corr. = 0.92

[using MINITAB where p value is not applicable])

17

Origin of data Current survey MCS 2004

Current survey MCS 2004

Current survey MCS 2004

Beach name Church Cove Gunwalloe Fishing Cove Poldhu Cove Date surveyed 09/10/2004 19/09/2004 16/10/2004 19/09/2004 09/10/2004 19/09/2004 Length surveyed (m) 185 100 500 125 140 100 Source of litter: % beach visitors 14.5 29.4 33.5 39.2 20.3 34.2 % fishing 46 46.9 12.2 28.3 44.7 45.6 % SRD 0.6 0.8 0.16 0.2 0.24 0.5 % shipping 0.01 2.3 2.6 2.1 3.07 2.8 % fly tipped 0 0 0.82 0.5 0.63 0.2 % medical 0 0.2 0.08 0 0 0.2 % non-sourced 37.5 20.5 50.7 29.7 31.1 16.5 total No. litteritems 340 1045 1220 2138 1273 1303 mean No.items/m

1.84

10.45

2.44

17.1

9.09

13

Table 3: Comparison of beach litter data collected by current survey and MCS 2004 on commonly surveyed beaches on the Lizard Peninsula

3.4 Impact of litter survey on litter density

The data set was investigated to identify whether the act of surveying and removing

litter from beaches affected the results of subsequent survey results from a specific

beach.

18

3.4.1 Repeatedly surveyed beaches within the current investigation

Within the total 37 beach surveys, 7 beaches were surveyed twice, and 6 surveyed

three times. Table 4 shows the number of litter items collected per metre of beach for

each beach with multiple surveys during this investigation.

Table 4: Repeated beach surveys - No. litter items per metre of beach surveyed Beach name 1st survey 2nd survey 3rd survey Loe Bar 1.89 0.71 0.5 Holywell bay 3.2 4.55 0.7 Chapel Porth 1.8 1.34 6.45 Coverack 2.57 8.7 5.1 Trevaunance 1.77 0.45 3 Poldhu Cove 21.5 6.8 5.8 Porthallow 8.5 8.4 Sunny Cove 2.94 1.36 Porthoustock 8.7 3.2 Mullion Cove 5.3 3 Swanpool 6.7 1.43 Church Cove 1.84 4.26 Gunwalloe Fishing Cove

2.44

0.13

Trend analysis is difficult given the nature of the data (see discussion of results,

below). However graphing the number of litter items collected per metre of beach

surveyed in consecutive litter surveys gives a ‘by eye’ impression of a decline in the

amount of litter (Fig. 1)

Of 19 surveys that have a subsequent survey in the same beach during the course of

this investigation, 14 or 73.68% show less litter collected in the subsequent survey.

19

Fig. 1 Repeated Beach surveys - impact of survey frequency on litter density

0

5

10

15

20

25

1st survey 2nd survey 3rd survey

Subsequent litter surveys

No.

item

s fo

und

per m

etre

Loe Bar

Holywell bay

Chapel Porth

Coverack

Trevaunance

Poldhu Cove

Porthallow

Sunny Cove

Porthoustock

Mullion Cove

Swanpool

Church Cove

GunwalloeFishing Cove

The dates of surveys conducted on a given beach more than once during the current

investigation are presented in Table 5

Beach Name 1st survey 2nd survey 3rd survey Loe Bar 14/10/2004 16/10/2004 01/11/2004 Holywell bay 13/10/2004 30/10/2004 15/11/2004 Poldhu Cove 09/10/2004 20/10/2004 14/11/2004 Chapel Porth 18/10/2004 30/10/2004 13/11/2004 Coverack 21/10/2004 03/11/2004 14/11/2004 Trevaunance 18/10/2004 30/10/2004 13/11/2004 Porthoustock 03/11/2004 14/11/2004 Sunny Cove 17/10/2004 17/11/2004

Gunwalloe Fishing Cove 16/10/2004 15/11/2004 Church Cove 09/10/2004 20/10/2004 Swanpool 11/10/2004 17/11/2004 Mullion Cove 09/10/2004 18/11/2004 Porthallow 21/10/2004 03/11/2004 Table 5: dates of survey for beaches undergoing repeated surveys within the current investigation

20

3.4.2 Impact of surveying on data from beaches surveyed by both the current

survey and MCS 2004

Three beaches surveyed in the current investigation were also surveyed as part of the

MCS BeachWatch annual beach litter survey. The MCS survey took place on 19th

September 2004, prior to the current investigation. The shared data set is summarised

in Table 3, and data for the number of litter items collected per metre of beach is

summarised in Table 6.

Total data Current survey

MCS 2004

Current survey MCS 2004

Current survey MCS 2004

Beach name Church Cove Gunwalloe Fishing Cove Poldhu Cove Date surveyed 09/10/2004 19/09/2004 16/10/2004 19/09/2004 09/10/2004 10/09/2004 Length surveyed 185 100 500 125 140 100 No. items per metre of beach surveyed: No. beach visitor items/m 0.26 3.1 0.51 6.7 1.8 4.5 No. fishing items/m 0.84 4.9 0.3 4.8 4.06 5.9 No. SRD items/m 0.01 0.1 0.004 0 0.02 0.1 No. shipping items/m 1.4 0.2 0.06 0.4 0.28 0.4 No. fly-tipped items/m 0 0 0.02 0.1 0.06 0 No. medical items/m 0 0 0.002 0 0 0 No. non-sourced items/m 0.69 2.5 1.23 5.1 2.83 2.2 total No.items 340 1045 1220 2138 1273 1303 mean No. items/m

1.84

10.45

2.44

17.1

9.09

13

Table 6: beach litter survey data on beaches surveyed by both MCS and current investigation in 2004

Of the 21 paired data points of litter items per metre of beach surveyed, grouped by

source of litter, 13 data pairs (61.9%) show greater densities of litter found in the

21

earlier MCS 2004 survey. When considering the total number of litter items collected,

all three beaches show higher litter densities found in the earlier MCS 2004 survey.

3.5 Final data set results

Excluding any subsequent repeated surveys, and removing the three beaches

previously surveyed by MCS 2004 leaves 15 beach litter surveys, representing 4.68

km of beach, and 14, 368 litter items collected, recorded and sourced. This final data

set is presented in Appendix 4 and is summarised in Tables 7 and 8.

Source of beach litter

Lizard Peninsula (Current Survey)

SW England data (MCS 2004)

National data (MCS 2004)

Beach visitors 20.4 37.7 38.6 shipping 2.26 1.8 2.2 non-sourced 44.1 39.5 34.8 Fishing 31.2 16.4 14.1 Fly-tipped 1 0.6 0.8 medical 0.04 0.09 0.1 SRD

0.95

2.6

9.3

Table 7: Summary of percentage contribution of sources of beach litter found in the Lizard Peninsula, SW England, and UK in 2004 comparing current survey data and MCS 2004 data

22

Source of beach litter

Lizard Peninsula (Current Survey) SW England (MCS 2004)

National UK (MCS 2004)

Beach visitors 0.63 1.65 0.73 Shipping 0.07 0.07 0.04 Non-sourced 1.35 1.69 0.66 Fishing 0.96 0.72 0.27 Fly-tipped 0.03 0.02 0.02 Medical 0 0.004 0 SRD 0.03 0.1 0.18 Total

3.07

4.28

1.9

Table 8: Summary of number of litter items found per metre of beach in the Lizard Peninsula, SW England, and UK in 2004 comparing current survey data and MCS 2004 data

3.5.1 North coast beaches compared with South coast beaches

Of the final data set, 5 beaches are situated on the North coast of the study region, and

13 beaches on the South coast (see map, Appendix 3). The data was processed

separately to identify differences in sources of litter on each coast (see Table 9).

23

South Coast North Coast

Source of litter No. items

per m. of beach % No. items

per m. of beach % Beach visitors 0.64 24.38 0.695 14.7 Non-sourced 1.18 44.7 1.84 38.96 Shipping 0.078 2.96 0.087 1.84 Fishing 0.62 24.39 2.0 42.45 Fly-tipped 0.025 0.009 0.04 0.9 Medical 0 0 0.003 0.08 SRD 0.018 0.007 0.05 1.09 Total

2.64

4.72

Table 9: Summary of beach litter sources on the north and south coast of the Lizard Peninsula

24

4. Discussion of Results

4.1 Limitations of collected data

A number of researchers have noted the difficulties of statistical analysis of beach

litter data (e.g. Tudor et al., 2002, 2003; Tudor & Williams, 2004; and see WHO,

2000 and Milton, 1999). These studies show that there is no broadly accepted

methods of statistical analysis of beach litter data. Although using various

multivariate analyses, e.g. Principal Component Analysis to identify spatial, temporal

and sourcing patterns in litter, suitable and rigorous techniques do not yet exist.

Difficulties include:

1. The litter surveys conducted are not a sampling of the beach litter, but

essentially a total collection of litter present on a given day. The data will not

necessarily represent a normal distribution that is a predicate for most

statistical methods (Milton, 1999)

2. Each beach has a unique dynamic system represented by factors including

ocean currents; human activity; weather conditions; shipping lanes; sewage

outlets; road access. These factors vary considerably over time, and are little

documented for the beaches in the study. Therefore there need be no

predictable relationship between the distribution of litter between different

beaches, and statistical comparison is invalid. There may be relationships

between different surveys on the same beach over long time periods, but the

majority of beaches in this study were surveyed for the first time

3. The act of surveying may affect the results of later surveys through the

removal of litter. This has been little studied by researchers, but evidence

presented here suggests such an impact, making subsequent survey data from

the same beach of questionable value.

4. The environmental impacts of different litter types are little known. The data

of presence/absence of litter items is practical in collection terms for the

volunteer participants, but relative data such as size, location and impact of

litter items cannot be practically collected in a widely accepted format.

Therefore where items are equated, e.g. a cigarette butt and a car engine would

25

receive equal status in the survey as representing a single litter item, any

analysis will be necessarily ignorant of overall impact.

Given the combined limitations of knowledge, data quality, and appropriate statistical

tools, data analysis must necessarily be qualitative to a degree. MCS recognise these

limitations (MCS, pers. comm. 15th September 2004) and consequently focus on trend

analysis of beaches surveyed over a period of time – the data becoming more valuable

with subsequent surveys. The data set presented here largely represents an initial

survey, with any subsequent data collected in later years capable of analysis relative

to these findings.

4.2 Validation of methodology

The MCS survey methodology is widely accepted even given the limitations

discussed above. The data set presented here can be confidently accepted given:

1. The relatively large proportion of beaches surveyed relative to the national

survey

2. The broad agreement of contributions from litter sources of the current data set

and SW regional data from the MCS survey

3. The quality of training given to volunteers in collection methodology and litter

identification

4.3 Impact of survey on litter density

The data presented clearly indicate a depletion of litter present following removal of

beach litter by a survey. This is apparent both within the current investigation and

following surveys as part of the national MCS survey. Surveys presented here are

separated by up to one month, with some re-surveys being carried out within days.

The appropriate time period after which subsequent survey data is valid cannot be

decided from this data set. However the observed effect of litter depletion by survey

means that future surveys should exercise caution, and that more research is needed.

26

4.4 Characteristics of beach litter in the study area

After removing data that may be affected by potential litter depletion by survey, the

beach litter findings for the study area of the Lizard peninsula south and north coasts

is presented in summary below. The data is summarised in comparison to MCS

findings for the SW region and the whole of the UK in 2004 in Table 10, and

presented graphically in Fig. 2.

Beach locations

Current study area

South West England

UK

Source of litter Number items/ metre % Number of items/m % Number items/metre % Beach visitors 0.63 20.4 1.65 37.7 0.73 38.6shipping 0.07 2.26 0.07 1.8 0.04 2.2non-sourced 1.35 44.1 1.69 39.5 0.66 34.8fishing 0.96 31.2 0.72 16.4 0.27 14.1fly-tipped 0.03 1 0.02 0.6 0.02 0.8medical 0 0.04 0.04 0.09 0 0.1SRD 0.03 0.95 0.1 2.6 0.18 9.3Total 3.07 4.28 1.9

Table 10: Summary of beach litter survey results by source

Fig. 2: Summary comparison of 2004 beach survey data by litter source

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

Current Survey SW England UK

Beach data set

Num

ber o

f litt

er it

ems

per m

etre

of

beac

h

Beach visitorsshippingnon-sourcedfishingfly-tippedmedicalSRD

27

It can be seen that the relative contributions of sources of beach litter in the north and

south Lizard Peninsula beaches have the following notable aspects:

• Total density of beach litter lying between the relatively high SW density and

the lower UK average

• High incidence of litter originating from fishing activities

• Low contribution of litter from beach users

• Low incidence of sewage-related debris (SRD)

Further notable aspects of these findings are:

Fishing – beach litter originating from fishing industry sources is already noted be

MCS as the highest in the South West region compared to anywhere else in the UK.

This study found fishing – related debris to be in even higher densities than in this

already high regional level.

Beach users – MCS found that the density of debris from beach users in the South

West region to be the highest anywhere in the UK. The current study area around the

Lizard Peninsula shows much lower levels of beach user litter, even lower than the

national levels.

SRD – sewage related debris was found by MCS to be a relatively smaller source of

litter than in the UK in general. This study finds that SRD is an even smaller part of

the beach litter burden in the study area than in the rest of the SW.

4.5 The North and South coasts around the Lizard Peninsula

The north and south coasts of the study area can be expected to be subject to different

sea-based sources of litter. Different currents and sea conditions, different adjacent

shipping routes; and possibly different use of beaches by recreational and fishing

communities are all factors that are likely to result in different sources and amounts of

litter appearing on the beaches on the coastal areas in question.

28

The data presented in section 3.5.1 show that the north and south coasts of the study

area show very similar densities of beach litter, with the notable difference of very

high levels of fishing sourced litter on the north coast beaches. The higher level of

overall litter density in the north coast (4.72 litter items per metre of beach, compared

to 2.64 items/m in southern beaches) is largely attributable to the high levels of

fishing debris. This figure is also impacted by the higher density of non-sourced litter

in northern beaches.

The study area of the current investigation can meaningfully be separated into beaches

of the Lizard Peninsula proper, on the south coast of Cornwall; and of beaches of the

northern mid-Cornwall coast, in the north of the study area. The beach litter survey

2004 data for these areas is summarised and presented alongside MCS 2004 data in

Table 11 and is presented graphically in Fig. 3.

Beach survey

location Lizard Peninsula Mid-north cornwall

coast SW peninsula United Kingdom Source of litter No. items/m % No. items/m % No. items/m % No. items/m %

Beach users 0.64 24.38 0.695 14.7 1.65 37.7 0.73 38.6non-sourced 1.18 44.7 1.84 38.96 1.69 39.5 0.66 34.8Shipping 0.078 2.96 0.087 1.84 0.07 1.8 0.04 2.2Fishing 0.62 24.39 2 42.45 0.72 16.4 0.27 14.1Fly-tipping 0.025 0.009 0.04 0.9 0.02 0.6 0.02 0.8Medical 0 0 0.003 0.08 0.004 0.09 0 0.1SRD 0.018 0.007 0.05 1.09 0.1 2.6 0.18 9.3Total 2.64 4.72 4.28 1.9

Table 11: summary of beach litter survey data for 2004 by source comparing north and south coasts of the study area

29

Fig. 3: Comparison of beach litter densities by source considering north and south coasts

0

0.5

1

1.5

2

2.5

Lizard North coast SW UK

Area of survey

Num

ber o

f litt

er it

ems

per m

etre

of

beac

h

Beach usersnon-sourcedShippingFishingFly-tippingMedicalSRD

As noted above, the data identifies exceptionally high levels of litter sourced from

fishing in northern mid-Cornwall beaches relative to the Lizard coast, to the SW

region, and to the UK as a whole. Similarly, non-sourced litter is high on northern

beaches, and is a higher proportion of the total litter burden in both northern and

Lizard beaches. Beach users contribute similar amounts of litter to the total as found

in the UK average in both northern and Lizard beaches – contrary to the trend of high

beach user litter in the SW.

30

5. Conclusions

5.1 Data analysis

Beach litter survey data is inherently limited in terms of quantitative analysis. Various

approaches to analysis have been tried, including relatively complicated techniques

such as multivariate analysis and Principal Components Analysis (PCA) but there is

considerable dispute as to the interpretation of results (see 4.1 above).

The value of the Lizard peninsula/north mid-Cornwall coast data set presented here

will become of greater value as surveys in subsequent years allow the analysis of

trends in beach litter deposition in terms of individual beaches and the study area in

total.

5.2 monitoring approach

The current investigation shows that the relatively simple MCS beach litter protocol

can be successfully applied to an intensive survey of beach litter in a specific study

area – in this case the Lizard Peninsula. Large amounts of data were collected with a

good level of confidence in the quality of that data. The intensive surveying of a

specific area is sustainable in being able to attract motivated volunteers, and in

obtaining adequate funding through grants and volunteer contributions. The relatively

high level of training, preparation and management of the volunteers is similarly

sustainable. This sustainability is demonstrated in that BTCV plan to continue the

beach surveys in the study area in 2005, and have plans to continue the Lizard surveys

into the future, and to carry out further intensive volunteer surveys in Devon (Ash

Pearson, Director, BTCV Cornwall, pers. comm. 7th January 2005)

5.3 beach users and SRD

Initial indications from this preliminary data set are that beach users and sewage

outfalls are a lower cause of beach litter than in the rest of the UK. This is interesting

in relation to MCS findings that beach users provide the highest source of beach litter

31

in the SW of England, in levels higher than elsewhere in the country. This indicates

that beach users and sewage outfalls need not be specifically targeted to reduce

marine litter in the Lizard peninsula/ north mid-Cornwall area.

5.4 Fishing industry debris

The high levels of fishing-related debris over the whole area and particularly on the

north coast indicate that councils and environmental groups should concentrate on

reducing marine debris from this source. As noted above, there is little available data

on the environmental impacts of marine litter, but 15% of seals in Cornwall display

injuries caused by discarded fish netting (Gweek National Seal Sanctuary pers. comm.

12th September 2004), which is the highest incidence of netting injury amongst seals

recorded in the world. Therefore fishing debris is indicated as a high impact source, as

well as being in unusually high density in the Lizard. This further implies that efforts

at litter reduction should be focussed on this source.

5.5 shipping sourced litter

The high proportions of shipping-related beach litter on the south coast of the study

area is not surprising given the many nearby shipping lanes using the English

Channel. However the actual densities related to shipping are in accordance with

MCS findings of high levels of shipping litter in the SW peninsula, and similar to the

findings of this study for the north mid-Cornwall coast. There is little available data as

to the impact of shipping debris on the environment, and the findings suggest that

further research should be carried out to ascertain the scale of the problem.

5.6 non-sourced litter

Levels of non-sourced litter on the Lizard peninsula are intermediate with the MCS

findings of very high levels in the SW region, and lower densities in the UK as a

whole. However, as a proportion of the whole, non-sourced litter is by far the highest

contributor of litter. Therefore more research is needed into what comprises this

portion of the litter, and attempts made to identify sources. If a particular source e.g.

32

shipping or fishing is the main contributor of un-sourced litter, this would represent a

major source against which reduction efforts should be focussed.

The north mid-Cornwall cost has a level density of litter due to non-sourced litter that

is higher than that MCS found for the SW region – already much higher than the UK

norm. As with the Lizard coast, this indicates the need for further research into the

source of these litter items I order to focus management effort and resources on

effective reduction.

5.7 Survey depletion of litter levels

The study clearly indicates that the act of surveying beach litter affects the results of

subsequent surveys. However the length of time over which this impact occurs canot

be derived from the available data.

This finding indicates that beach clearance does have a noticeable impact – at least in

the short term – and therefore that beach litter clearances is an effective approach to

improving the local environment in the short term. This may be relevant to the timing

of beach litter clearances designed to improve the environment for tourists over a

short summer season.

The depletion of litter by surveying indicates that future intensive survey efforts

should take care when gathering data from repeated surveys of individual beaches in

case results are affected. However, the amount of time that should be left between

surveys is not clear. Very few studies have addressed the depletion effect of litter

surveying. For example Storrier (2004) conducted monthly surveys on beaches in

Scotland but did not consider depletion effects.

Further research would provide data by which the cost-effectiveness of beach clearing

could be evaluated; and appropriate time-intervals between surveys calculated. Future

intensive surveys of the current study area will provide appropriate data to calculate

the duration of a beach clearance effort, and future BTCV beach surveys should

deliberately design the interval between repeated beach surveys in order to address

this issue.

33

References ASH (1995) Beach Litter Management in Scotland. An Assessment of current procedures and recommendations for best practice. ASH Consulting Group, London, UK. Australian Environmental Protection Agency (undated). Monitoring the presence/extent of litter in estuarine, coastal and marine systems. [Online] available from: http://www.nrm.gov.au/monitoring/indicators/estuarine/pubs/presence-of-litter.pdf [Last accessed 5th July 2004] CCC (2003) State of the Cornish Environment 2002 Baseline edition. Cornwall County Council, Truro, UK. Covey, R., and Laffoley, D.d’A. (2002) Maritime State of Nature Report for England: getting onto an even keel. English Nature, Peterborough, UK. Davenport, J. & Rees, E.I.S. (1993). Observations on neuston and floating weed patches in the Irish Sea. Estuarine, Coastal and Shelf Science, 36, 395-411. DEFRA (2002) Safeguarding our seas: A strategy for the Conservation and Sustainable Development of our Marine Environment. Department of Food and Rural Affairs, London, UK. Donohue, M.J. (2003) How multiagency partnerships can successfully address large-scale pollution problems: a Hawaii case study. Marine Pollution Bulletin 46 (6) pp. 700-702 EA/NALG (2000). Assessment of aesthetic quality of coastal and bathing beaches. Environment Agency and the National Aquatic Litter Group, London ENDS (2002) Commission kicks off work on marine conservation strategy. ENDS Report 333, October 2002, pp 50-51 Faris, J. & Hart, K. (1994). Seas of Debris: A Summary of the Third International Conference on Marine Debris. Alaska Fisheries Science Center, Seattle. Garitty S.D. and Levings S.C. (1993) Marine debris along the Caribbean coast of Panama. Marine Pollution Bulletin 26: 317-324 Goldberg E.D. (1995). Emerging problems in the coastal zone for the twenty-first century. Marine Pollution Bulletin 31: 152-158 IMO (2001) Promotion of Implementation and Enforcement of MARPOL 73/78 and Related Codes. MARPOL Annex V and Marine Debris. London, England: International Maritime Organization, 2001

34

Jones, L.A., Irving, R., Cork, M., Coyle, M.D., Evans, D, Gilliland, P.M., & Murray, A.R. (2003) South Western Peninsula Marine Natural Area Profile: A contribution to regional planning and management of the seas around England. Peterborough: English Nature. MaLiTT (2002) The impacts of marine litter. Report of the Marine Litter Task Team. Marine Pollution Monitoring Management Group, Department of the Environment, UK MCS (2005). Beachwatch 2003 – Nationwide Beach-Clean & Survey Report. Marine Conservation Society, Bristol, UK MCS (2004). Beachwatch 2003 – Nationwide Beach-Clean & Survey Report. Marine Conservation Society, Bristol, UK MCS(2003). Beachwatch 2002 – Nationwide Beach-Clean & Survey Report. Marine Conservation Society, Bristol, UK Milton J.S. (1999) Statistical methods in the biological and health sciences 3rd Edition. WCB/McGraw-Hill, London, UK. NRA (1994) Sources, pathways and sinks of litter within riverine and marine environments. National Rivers Authority, UK OSPAR Commission (1995). OSPAR IMPACT Working Group Summary Report. October 1995. OSPAR Commission, London OSPAR Commission (2004) Dumping of wastes at sea in 2001 and 2002. Biodiversity series, OSPAR Commission, London Pringle C.R. Research Proposal – Marine and coastal litter on the Lizard Peninsula Cornwall. MSc. Research Proposal, InteREAM, University of East Anglia, U.K. Rees, G. & Pond, K. (1995). Marine Litter Monitoring Programmes - A review of methods with special reference to national surveys. Marine Pollution Bulletin, 30:103-108. Storrier K.L. (2004) The Forth Coastal Litter Campaign: Working towards a litter-free Forth. Forth Estuary Forum, Rosyth, Scotland. 72pp Tudor D.T., Williams A. (2004). Development of a ‘Matrix Scoring Technique’ to determine litter sources at a Bristol Channel beach. Journal of Coastal Conservation. 10: 119-127 Tudor D.T., Williams A. (2001). Investigation of litter problems in the Severn Estuary/ Bristol Channel area. R&D Technical Summary E1-082/TS. Environment Agency, Bristol U.K.

35

Tudor D.T., Williams A.T., Phillips M.R. and Thomas M.C. (2002) Qualitative and quantitative comparisons of some indices suitable for litter analysis. Littoral 2002, The Changing Coast. EUROCOAST/EUCC, Portugal 325 pp. Tudor D.T., Williams A.T., Randerson P., Ergin A., and R.E. Earll (2003). The use of multivariate statistical techniques to establish beach debris pollution sources. Journal of Coastal Research SO 36: 716-725 US Commission on Ocean Policy (2003) Reducing Marine debris- a preliminary report. National Oceanic and Atmospheric Administration, Washington D.C.

Velander K.A. and Mocogni M. (1998) Maritime litter and sewage contamination at Cramond Beach, Edinburgh – a comparative study. Marine Pollution Bulletin 36: 61-65 WHO (2000). Monitoring Bathing Waters: A Practical guide to the design and implementation of assessments and monitoring programmes. World Health Organisation. Geneva, Switzerland

36

Appendix 1: Beach Survey volunteer newsletter

37

Appendix 2: Marine Conservation Society recording and sourcing forms for beach litter surveys

38

Appendix 3: Map of approximate locations of beaches surveyed

39

Appendix 4: Final data set of beach surveys excluding those with preceding surveys carried out within 2 months