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ReportofOfficialVisittoBIOT,
April-May2014
ChiefScienceAdvisor,BIOT
Government
Dr Mark Spalding
Chief Scientific Advisor to the
British Indian Ocean Territory Administration
Department of Zoology,
University of Cambridge,
Downing Street, CB2 3EJ,
UK
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2
Contents
Trip itinerary
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3
Introduction
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4
Key Action Points
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4
Public works
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9
Freshwater
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9
Wastewater treatment
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10
Waste and recycling
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11
Pollution in the lagoon
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13
Energy supply and generation
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13
Coastal engineering
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13
Imported aggregates for coastal engineering
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15
Marine and Fishing
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16
Monitoring of legal fishing
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16
Boat-based fishing from DG
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16
Shore fisheries
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16
Yacht fisheries
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16
Surveillance and
capture...................................................................................................................
17
Shark human interactions
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18
Biodiversity Conservation
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20
Habitat Restoration
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20
Invasives
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21
Rat Eradication
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21
Public engagement
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21
Boats in northern atolls
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22
Waste
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22
Anchors
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23
Science and
observations......................................................................................................................
25
Facilities
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25
Coastal
erosion..................................................................................................................................
25
Fishing impact
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26
Mangroves
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26
Reefs..................................................................................................................................................
28
Coral condition and disease
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28
Citizen science and conservation
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30
Expanding the baseline
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30
Closing comments
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31
Acknowledgements
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32
References cited
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32
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Trip itinerary
29 April
Travel. Flight with XO
30 April
BritRep meetings
Swim test and mission briefing for trip to outer
islands
US Commanding Officer
PWD Public Works Department staff.
Visits:
Water treatment facility
Coastal revetment work
Quarantine area for coastal revetment stone
Fuel loading bay
Nuclear submarine dock
Fuel pipelines
Drive along E and N shore of W DG new
pipeline
1 May
Visit with BritRep
Dive store
Waste disposal unit
Turtle Cove
Firing Range (British) and adjacent coast
(turtle nesting monitoring site)
Native tree restoration sites
Plantation and Graveyard
Sharks Cove
Metal recycling
Sewage ponds
Plant Nursery
Fishing marina
2 May
W Great Chagos Bank
Eagle Island old settlement, mangrove and
W shore
Dive off W shore
Dive off N Brother
Middle Brother circumnav
3 May
Peros Banhos
Dive of W end Ile de Coin
Ile Vache Marine brief snorkel and circumnav
Ile de Coin settlement
Moresby Island mangroves
4 May
Salomon and N Great Chagos Bank
Dive of S Ile Anglaise
Dive in anchoring area nr Boddam
Ile Boddam settlement
Snorkel N coast Nelson
Nelson circumnavigate
5 May
Visits with XO to E arm of Diego Garcia
Turtle Cove
Restoration site Minni Minni
Barton Point
Snorkel lagoon mouth Barton Point
Beach visits on lagoon and ocean side
Evening dinner and debrief with XO, and BritRep
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Introduction
The following detailed account covers my first visit as Chief
Science Advisor to the Government of
the British Indian Ocean Territory in April-May, 2014. The
overall aim of this visit was in some ways
focused on familiarisation with the Territory, including Diego
Garcia and the northern atolls. In the
process of this visit I was able to meet key personnel and to
visit much of the infrastructure around
DG, as well as to visit a number of islands and reefs across the
Great Chagos Bank, Peros Banhos and
Salomon Atolls.
Clearly it is not possible for one person to be expert in all
aspects of environmental issues ranging
from biodiversity protection to restoration to waste treatment
and munitions disposal. To this end
my remit was rather to observe and absorb. During this process I
took extensive notes (and
photographs). I was able to undertake some further research into
key questions during and after the
trip, and have also benefitted from some feedback from key
personnel, which has helped to cut
down the number of questions raised.
The structure of the report breaks into four broad sections,
which are somewhat pragmatic and
overlapping, but help to draw the information together in a more
meaningful flow:
Public Works focuses on aspects of infrastructure and utilities
on Diego Garcia activities
associated with the human habitation which have the potential to
have a significant impact
on the natural environment
Marine and fishing focuses entirely on the range of ongoing
fishing activities both around
Diego Garcia and the entire territory and on the efforts to
manage these.
Biodiversity conservation focuses on efforts to restore
biodiversity, or reduce impacts
through targeted management interventions.
Science includes the broad scope of ongoing research and
research needs in Chagos,
including research needed for support of management areas above,
but also critical baseline
work to describe Chagos and better understand its importance,
role and settings.
Throughout the body of this report I highlight a number of
issues which would merit further thought,
discussion or action. These same comments have been more briefly
summarised in the Key Action
Points below.
Key Action Points
PUBLIC WORKS
Freshwater
We should take stock of operations and look at future plans for
the new water treatment plant
including the deepwater waste disposal, any further plans for
tree-felling around wells, estimates of
waste, chemical constituency of that waste, and volumes of
waste.
Wastewater treatment
The treated effluent released onto the reef could be having an
impact, it may be minimal, however it
evidence is needed. On future visits it would perhaps be useful
to visit the adjacent beach area and
even (at low tide) walk out to the actual outfall, but such
observations are insufficient to understand
any impacts on the adjacent reef.
There should be some water quality sampling at surface and
across a depth profile around the
outfalls and adjacent reef areas so the imprint of this treated
waste water discharge can be more
accurately described. It would further be valuable to assess
ecological impacts through diving or
video surveys.
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Waste and recycling
It may be valuable to investigate the best methods for disposal
of large volumes of illegally caught
fish. Are there concerns about this waste, either in terms of
volume, leachate or indeed human
health?
Pollution in the lagoon
The findings of the recent water quality assessment studies are
eagerly anticipated, but it would also
be valuable to get an understanding of the regular, ongoing
water quality testing work and its
findings.
It would be of interest to know if the water quality studies
would be sufficient to detect any
influence of leachates from the old (unlined) waste disposal
site.
The recent observation of an algal bloom in Diego Garcia points
to a potential human health hazard
as well as a threat to marine life. It would be valuable to know
more about any other such events
and to develop a reporting mechanism.
Energy supply and generation
Fuel pumping from supply vessels to the land (or other such
transfer of toxic or polluting materials in
the lagoon) should continue to be prohibited during high winds
or waves. Suppliers are under
contract and clearly under pressure to transfer to tight
time-schedules, so it would be advisable to
formalise current best practise.
The large trees/branches overgrowing the fuel pipelines from the
POL Pier to the POL Farm should
cut back to avoid risk of damage to pipelines
Coastal engineering
It would be useful to establish how the sedimentation threat
from ongoing coastal engineering was
assessed, how effectively the simple measures (working at low
tide and stopping work if large
sediment plumes are seen) are being applied and what reasoning
was used in assuming further
measures such as sediment skirts were not considered
necessary.
There may be value in requesting an independent expert review of
the Moffatt and Nichols
proposals for coastal engineering.
It would further be useful to know if there have been any impact
studies of sedimentation from
dredging to maintain deepwater harbours and channels, and to
find out about what use is made of
siltation avoidance measures such as siltation skirts.
Advisory documentation should be developed for staff and customs
responsible for inspecting
aggregates being imported into Diego Garcia for coastal
engineering. These should explain the very
high costs of any potential plant or animal invasion and
describe the process for conducting
thorough customs inspection prior to and during offloading.
MARINE AND FISHERIES
Fishing
Better reporting of the full recreational fishery around DG is
clearly needed, particularly of the
shore-based fishery, but there could also be value in
investigating any whether fishing from large
vessels at anchor is taking place, which has been suggested by
some observers.
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A detailed description and summary of the information from the
DG and yacht based fisheries return
forms should be obtained. We need to consider how to improve
returns on the shore (and possibly
yacht) fisheries.
There would be great value in commissioning a new creel survey
to assess these fisheries.
There may be some value in providing improved information to
reduce risks of shark-human
interactions, and amendments to management, including, for
example, possibly separating of
swimming areas from fish-landing areas.
Surveillance and capture
The Fisheries Patrol Vessel (FPV) may already be having a
valuable impact on the illegal demersal
fishing, although it is difficult to quantify this success in
terms of the proportion of IUU vessels that
are captured, or the deterrent value. There is a far greater
challenge to impact possible IUU tuna
catch. For both fisheries there is a need to try and ascertain
the levels of illegal fisheries irrespective
of capture.
There could be value in encouraging greater dialogue and
collaboration between the various parts of
the BIOT Administration specifically MRAG and the BritRep/BIOT
team on-island to enable further
co-ordination of surveillance.
For the longer term it would be valuable to have a rational
discussion with all players on vessel and
surveillance needs, science support and possible options. There
are clearly different opinions, but
also challenging budgetary constraints. An initial workshop
could help to kick-start this process
BIODIVERSITY CONSERVATION
Habitat Restoration
There is a need to review existing information on the native
vegetation restoration efforts, to
understand overall policy, species planted, area covered,
techniques and proposals for follow-up.
This should be used to develop advice on future efforts.
There is a possibility of engaging existing ground-staff and/or
volunteers to extend this work.
Current grounds management in this area is somewhat ad hoc, so
such guidelines could yield
significant benefits at little to no additional costs.
There may also be a need for a field based review of these
projects, which would enable a more
detailed understanding of progress, including successes and
failures, and the costs and benefits of
the different techniques and approaches that have been attempted
to date.
Invasives
There would be value in developing a list of pest species for
Chagos and DG, which might provide a
target for managers in developing pest control beyond that of
ironwood, rats, cats and chickens.
Public engagement
Increasing public interest in the natural environment around
Chagos could lead to greater respect
for the natural environment, but also to other benefits in terms
of human health and reduced waste
and energy consumption. There is a need for more direct
communication and education, including
more signage, but more especially more active communications
through the radio/TV. Visiting
scientists should be encouraged to give presentations.
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Boats in northern atolls
Some messaging would be of considerable benefit in the northern
islands. Clearer and more forceful
signage regarding regulations are needed to encourage correct
behaviour, but by making this
educational and informative it might help engender
responsibility. Signage should be seen as an
infrequent but ongoing cost as signs will fade, become outdated
or simply look old and be ignored.
The immigration and customs visit could also be used to remind
yachts of the rules, encourage them
to return the fisheries forms and of course to keep an eye out
for any evidence of rule breaking.
Concerns remain about the impact of anchors on the seabed in
Salomon Lagoon. It would be
valuable to obtain a more detailed understanding of the
distribution of important benthic habitats,
and perhaps to undertake a (necessarily more sparse) survey of
seabed features in Peros Banhos in
order to ascertain the relative importance of anchorage sites.
The observations from Salomon also
underscore the importance of fixed moorings.
There would also be some value in detailing the exact GPS
locations for the current set of sites used
for anchoring by the FPV to be passed on to future vessels and
further to restrict anchoring to these
or a similar restricted set of locations to avoid wide
damage.
SCIENCE AND OBSERVATIONS
Coastal erosion
There is an urgent need to develop a robust picture of natural
coastal dynamics both around Diego
Garcia and the northern atolls. This should include reliable
long-term studies, led by experts in
coastal geomorphology, and setting baselines for an ongoing
assessment, which will be of value both
for coastal planning in Diego Garcia and in ongoing discussions
about resettlement.
Fishing impact
Although subsistence fishing from the FPV is permitted during
operations, there would be some
benefit in providing guidance and limiting the spatial extent of
fishing from the FPV. The primary aim
of such an approach would be to curtail any future expansion,
but also to signal the importance of
no-take in Chagos and to ensure that some locations are truly
without any fishing impact. Closing all
fishing from FPV would probably be counterproductive.
Mangroves
It is not clear that any urgent management intervention is
needed for the mangroves, but ongoing
scientific observation and perhaps more detailed mapping and
description would be valuable.
Corals and disease
Detailed reports on disease are expected shortly from the most
recent science expedition and
should be given close attention.
Citizen science and conservation
A summary of the contribution of Diego Garcia based personnel to
conservation and science, would
provide a powerful message, and could be enhanced with a review
of the range and potential for
future citizen science and conservation work, which might serve
to encourage ongoing and new
efforts and would aid the transfer of skills and knowledge to
new personnel.
Scientific baselines
There remains is a need to understand environmental settings
around Chagos more broadly in terms
of geography and discipline (ecology, oceanography,
geomorphology), through continued expansion
of basic descriptive science, particularly in areas where there
has been little or no observation to
date (both in terms of geographic location and key
disciplines).
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A science plan already exists and work is underway to develop a
conservation and management
plan. While there is overlap between these, it is appropriate
that they should be maintained as
distinct outputs. Critical to such planning tools is a vision of
need and prioritisation, particularly to
guide the necessarily limited budgets of the BIOT
Administration, but also to help in the assessment
of proposals for other visiting scientists and the potential
engagement of new partners in
conservation work.
There is also a strong need for a centralised data store for
environmental information on Chagos,
including findings from the science, from the fisheries patrol,
and from non-sensitive environmental
studies around DG by military and contractual visitors. As much
as possible should be made open
access, with data-sharing protocols to be determined and agreed
to as an a priori requirement for all
those working in Chagos.
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Public works
Freshwater
Freshwater has been extracted from the freshwater lens in two
locations. Visit to N site, where
water is pumped from around 100 wells distributed through
adjacent forest areas. They have a
number of test wells where they check levels and if there are
signs of falling levels nearby wells are
closed off with extraction redistributed across the remainder.
Current supply is easily sufficient for
resident population, but need to have readiness for
visiting.
The southern area of water supply, near to the airport is now
being connected with a new pipeline
to a new treatment plant under construction. The S site was
closed due to its proximity to two major
oil spill sites although not directly adjacent, there was a fear
that water abstraction might lead to
lateral flow of polluted water into this area. Apparently there
is some slight risk of hydrocarbon
contamination of this water, so this is being tested. Prior to
the spills this water was considered
better quality than the northern site, with lower organic
content and conductivity. This has been
attributed to the grass cover over the S wells, rather than
forest over the N wells.
Raw water from these lenses is generally high in organic content
and so is treated with chlorine, but
this leads to high levels of trihalomethanes, making it
non-potable. Potable water is currently
purified with nanofiltration.
An effort is underway to improve water quality with a
requirement to make all water potable
throughout base. This centres around a $27 million project
underway to bring in nanofiltration, and
to upgrade supply tanks and pipe as necessary. The re-activated
southern lens will also be connected
to the new water treatment facility.
Building work on the new water processing plant (left), and the
pipeline connecting to the southern water supply (right)
Two prior reports from the previous CSA have discussed these
issues. There were concerns that
water abstraction was high and potentially threatening to
vegetation, some wells had had to be
abandoned. There were concerns over plans for removing large
numbers of trees, apparently to
reduce evapotranspiration, but there may be some confusion here.
The only trees being felled were
for the building work around the new water purification plant.
Further concerns were raised about
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the inefficiency of nanofiltration or reverse osmosis this is
not only linked to the increased demand
of water needed to cover that waste, but also the disposal of
waste. The wastewater is still fresh, but
with relatively high concentrations of the undesirable organic
and mineral compounds. I was told the
current plan for this wastewater is pumping to deep storage at
180ft, rather than pumping into
wastewater treatment. It is not clear where this storage will
take place.
We should take stock of operations and look at future plans for
the new water treatment plant
including the deepwater waste disposal, any further plans for
tree-felling around wells, estimates
of waste, chemical constituency of that waste, and volumes of
waste.
Wastewater treatment
Wastewater receives secondary treatment in two treatment plants.
The key treatment is in lined,
open, ponds with mechanical aeration, and benefitting from UV
irradiation from sunlight. Treated
wastewater is monitored to ensure compliance to DGFGS discharge
standards. Chlorine is added
prior to release. Wastewater is then pumped via pipelines to be
released at the reef crest in two
locations. There appears to be no ongoing monitoring of the
impact of these releases and no
ongoing water quality testing.
Sludge is removed during major repairs of liners (approximately
once every 10-15 years). Sludge
can be dried using a sludge drying bed or in the sewage lagoon
once the wastewater is removed.
Sample from dried sludge is collected and sent off-island for
hazardous waste characterization. If
found hazardous, sludge is shipped off-island for treatment and
disposal. If found non-hazardous,
sludge is buried in the landfill or use as compost materials
with green waste (e.g. tree trimmings and
grass cuttings). (Diego Garcia Environmental Officer pers comm,
1 June, 2014).
One of the sewage treatment ponds
I am concerned at the assumption that these treated waste water
discharges are okay. I have been
told by the previous CSA that his inspections were fairly
cursory. The literature on the impact of
sewage pollution of coral reefs is mixed. There is some evidence
that in open ocean areas secondary
treated sewage, rapidly diluted, has relatively little impact.
By contrast there is a growing body of
evidence that sewage pollution can be contributing to reduced
reef condition (Reopanichkul et al.,
2009), harmful algal blooms (Lapointe et al., 2005) and indeed
to coral disease (Sutherland et al.,
2011; Voss and Richardson, 2006). There will be a local impact,
and it would be useful to
characterise that impact and to consider if there are simple
interventions which might reduce this.
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It is not possible, without evidence, to say that all is fine.
On future visits it would perhaps be
useful to visit the adjacent beach area and even (at low tide)
walk out to the actual outfall, but
such observations are insufficient to understand any impacts on
the adjacent reef. There should
be some water quality sampling at surface and across a depth
profile around the outfalls and
adjacent reef areas so the imprint of this pollution can be more
accurately described. It would
further be valuable to assess ecological impacts though diving
or video surveys.
Waste and recycling
Broadly speaking
Metal waste is stored to be taken for recycling. This is
collected every 2-3 years by a
commercial company who buy this waste. This process includes
entire vehicles.
Toxic waste is dealt with by HazWaste site, and aim is to shift
off-island
Green waste from tree-cutting etc is held in green waste
dump
Glass is pulverised, mixed with aggregate or soil and used as
landfill cover material
All other waste is taken to incinerator and landfill
At the disposal plant all incoming waste around 10 tonnes per
day is sorted by hand to remove
glass, metals and toxic matter (batteries, paints, aerosol cans,
adhesives). There are two
incinerators, with one running and one in reserve.
Hand-sorting of waste (left) followed by twin chamber
incineration
The output ash represents an 80-85% reduction by mass this ash
is tested (twice a year) for toxicity
(e.g. presence of heavy metals). If toxins were detected above
predetermined maximum levels the
ash would have to be treated as hazardous waste, to be shipped
to the US for proper disposal (it is
not clear this has ever happened).
The ash is then taken to landfill pits, where it is covered,
typically daily before the close of business.
The cover material consists of a mixture of soil, aggregate,
sandblasting grit and pulverised glass or
mulched tree limbs. These landfill pits are lined and leachate
collects along a channel along the W
margin. This leachate is tested on a monthly basis. It is pumped
to deep storage at 180 ft depth
below the atoll below the landfill (and thus far from any
freshwater wells). It is not clear to any of us
whether this means of disposal is better or worse than adding
this waste to ongoing sewage
treatment, which is more typical.
Current waste pits were planned to last 30 years. But last year
there was a complete failure of both
incinerators for 8 months. A decision was taken to dump the
waste, without open burning, in same
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pits (CSA was consulted and was ambivalent about possible
advantage of burning, while open pit
burning was actually not permitted under Final Governing
Standards). 8 months unburned waste
(which was still sorted for metal and toxics) used up 5 years
equivalent of landfill with ash. There are
no plans to re-treat this waste.
Fish catch from illegal vessels this can amount to several
tonnes. This is buried, unburned, at the
north end of the old (unlined) landfill site. It would be
interesting to know if there are concerns
about this waste, either in terms of volume or leachate, and
whether there might be alternatives.
Until 2007 waste was burned in open and unlined pits. This
material was covered over by a 4ft cover
of the sand dug from the new pits. From 2007-2011 some open pit
burning continued for the
removal of wooden materials (pallets and construction debris)
with BritRep approval all such
burning is now prohibited under the Diego Garcia Final Governing
Standards 2011. Clearly there will
be ongoing leaching from these old landfills for decades. This
is NOT being monitored (see pollution
in the lagoon, below).
All toxic waste is processed with HazWaste, indoor facility
where it is held prior to removal from
island. A large amount of asbestos remains on-island. Some has
been buried, some was taken off-
island, the rest is not stored with HazWaste, but there is no
clear plan for what to do with this.
The small arms firing ranges are also a source of toxic waste
(primarily lead and other metals). The
waste (spent bullets) are removed from these sites through a
process of sifting the sand bank behind
the range on a regular basis. I believe this waste is treated as
hazardous and taken off-island.
The southern firing range
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Pollution in the lagoon
There are ongoing water quality studies across the lagoon, and
these are being used in a new review
which is also modelling water flows studies and investigating
the condition of lagoon corals. While
these findings are eagerly anticipated it would also be valuable
to get an understanding of the
wider, ongoing water quality testing work and its findings.
We need to assess if there is any sign of leaching from the old
(unlined) waste disposal site
influencing the recent and/or the ongoing water quality
assessments in the lagoon and to follow
up with a consideration of the value of any further review of
this hazard.
An environmental officer on Diego Garcia mentioned a red tide
event (a bloom of planktonic algae,
typically dinoflagellates) in the lagoon ~8 months ago. He
bought this up as an example of the sort of
thing that could be linked to the draining of leachate into the
lagoon. Whatever the cause (and
these can be natural) they are a potential human health hazard
as well as a threat to marine life. It
would be valuable to know more about any previous such events
and to develop a reporting
mechanism.
Energy supply and generation
There are two diesel power stations on island. Storage
facilities are replenished as necessary.
Fuel is pumped from a special port (POL Pier) via fixed
pipelines and a twin pollution boom is
deployed when fuel is pumped (high winds and heavy waves during
a recent pumping exercise led to
an order from BritRep for pumping to be halted as waves were
breaking over the booms. Initially
there was some objection to this by the suppliers.
The POL Pier with pipelines and pollution boom
The fuel pipelines for different fuels are currently slightly
over-hung by some large trees. There is a
requirement that overhanging branches be cut to reduce risk of
damage to pipelines but the
responsibility for this is under dispute. Although unlikely, a
tree or branch-fall on these pipelines
while fuel is being pumped would be most unfortunate. The
problem of large trees/branches
overgrowing the fuel pipelines should be resolved.
On renewable energy, there are also plans for a major new
photovoltaics installation near Fuel
depot. (This area is currently grass and scrubby ironwood
forest.) It is somewhat surprising that
there is no heat capture from the incineration plant as this
could also be used to generate energy.
Coastal engineering
Coastal erosion is a major problem in several parts of the
island as identified in the Moffat and
Nichol report (Moffatt and Nichol, 2013). Prior efforts at
coastal defence have involved ad hoc
armouring or dumping of concrete and other materials, but major
efforts are now underway for
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well-engineered revetments. Some of these were built in 2011/2
and work is now continuing to in
front of CPO Club
There is a potential impact during building of sediments being
re-suspended and moving to
surrounding areas. Given the high sensitivity of corals to
sediment damage, it is fairly common to
adapt coastal engineering practices to minimise these impacts,
for example using sediment skirts to
surround areas of work (PIANC, 2010). I was told that work is
undertaken at low tide and it was
suggested (though not clear) that work may be halted if large
sediment plumes were being
generated. It is not clear whether this is really being put into
practise or how effective it might be.
There were no reefs visible in the immediate vicinity of these
works, and it is possible that most of
the sediments are quite heavy sands which might rapidly
resettle. Even so, it would be valuable to
know if this threat was properly appraised, how effectively the
simple measures are being applied
and what reasoning was used in assuming further measures such as
sediment skirts were not
considered necessary.
Edge of existing revetments (2012) in front of BOQ7 and adjacent
beach with material in place for building revetments from here to
CPO Club
Understanding of the impacts of coastal engineering is never
simple, and even the most rigorously
researched and planned interventions can lead to unexpected
consequences elsewhere. The
proposals for engineering work recommended by Moffatt and
Nichols appear to be thorough,
however there would be some value in getting an independent
expert to review these. Even if they
are well-planned, it might still be expected that such
interventions could lead to changing patterns
of coastal erosion and deposition elsewhere
A substantial revetment has been built beneath the lighthouse at
Mini Mini. There have also been
two very minor coastal defence efforts in southern DG (ocean
side) and western DG (lagoon side)
using large rock armouring, where the road is been threatened by
erosion. These were opportunistic
dumps, without any effort at design, and are unlikely to be
highly effective, but equally not likely to
be having any negative impact.
The other fairly regular form of coastal engineering is dredging
to maintain deepwater ports and
channels. The previous CSA expressed concerns about the storage
of dredge spoil and a storage area
was set aside. It would be useful to know if there are any
impact studies of sedimentation from
these activities and to know more about the use of siltation
avoidance measures such as siltation
skirts (PIANC, 2010)
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Imported aggregates for coastal engineering
Aggregates are shipped in from Mauritius (with an earlier load
of granite from Malaysia). Clearly
there is a risk of shipment of soil or living plant or animal
matter. Current policy is that for any new
load a 25lb sample should be submitted and held in quarantine
for 45 days. This is placed outdoors
on a concrete pad by the Pest Control Shop. After this bulk
transport is offloaded at the open area by
the Port Ops. An authorized representative of the Contractor
and/or quality control representative is
required to visually inspect each load of the material in the
presence BIOT customs or British
Representative. Materials are then held in quarantine for 14
days to observe if any foreign plants
are present. 14 days is insufficient for germination and growth
of many seeds, and the most
important part of this task is the inspection of materials, and
indeed the inspection of the materials
prior to loading in the port of origin by the contractor, which
is also a requirement under US
regulations on this issue.
A brief visit to the newly arrived and quarantined rocks showed
the vast scale of operation with
aggregates from gravel to very large rocks. I walked around and
up on to some of these piles and did
not see any sign of soil or vegetation. Both PWD and Britrep
were at pains to assure me of the
lengths they go through to avoid contamination and this is now
doubtless the case, although
originally concern was raised based on an opportunistic
observation of contamination by soil, seen
by the previous CSA.
Some of the substantial stockpile of imported aggregates for
coastal engineering
Overall it seems likely that reasonable measures are being taken
here but the risks are very high and
the costs of just one aggressive alien introduction could be
enormous. Vigilance remains key
clearly the contractors have prime responsibility, however the
US and the British Authorities as
independent verifiers at the port of arrival should take their
roles seriously. Advisory
documentation should be developed building on the experience of
current customs staff, clearly
stating these risks and explaining in simple terms the process
for conducting thorough customs
inspection prior to and during offloading.
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16
Marine and Fishing
Monitoring of legal fishing
Boat-based fishing from DG
Personnel on DG are able to fish from a number of boats, notably
3 Makos and 3 Boston Whalers
which are booked prior to use.They mostly used at weekends. The
Boston Whalers can fish outside
the lagoon (this has been recently re-allowed, following a
period of closure linked to an accident in
2011). There is also an LCM (Landing Craft Marine) which goes
out on weekends this can
theoretically take ~50 but will typically take up to 15 people
trolling outside the lagoon.
With the lagoon a large area is open to fishing, but this this
area is zoned, with fishing rotated
around zones through the year. Prior to this visit a member of
the recent science expedition had
expressed concern that fishing in the lagoon was having a clear
impact on grouper populations. They
also suggested that there might be some fishing from the large
vessels at anchor. An impact on the
grouper population is quite likely, but it is more likely this a
result of the small boat and coastal
fisheries. The vessels at anchor have only a small crew, they
are very high out of the water, and they
have relatively small spatial footprint over non-reef (or former
reef) areas. There still remains a
need to ask US commanders to confirm activity from large vessels
at anchor, and regulate
accordingly.
All boats must report catches numbers of lines, area visited and
fish caught, including weight (not
number of fishers, or numbers of hooks sometimes fishers will
have multiple lines and several
hooks on each). These forms are managed by MWR and entered into
a spreadsheet forms and
spreadsheet are sent direct to MRAG for analysis (SFPO is
copied). John Pearce at MRAG is
responsible for this data.
Generally big game fish (marlin/sailfish) are not targeted and
are considered quite rare.
Shore fisheries
This takes place 7 days a week on both inside and outside of DG,
including much is evening and night
fishing with lights. Reports from shore-based fishing are
voluntary so are likely to be a large under-
estimate of catch. There is no real incentive to report catches,
while the perceived risk of infringing
poorly known regulations is probably a strong disincentive.
Further many of the fishers have poor
English and most would not be aware of the fish names in
English.
Better reporting of the full recreational fishery around DG is
clearly needed. SFPO suggested that
anonymous reporting, with forms in native tongues, might improve
returns. A system of rod
licensing could further help as owners of rods would be asked
why not returning fisheries forms.
Another creel survey for all fisheries would be very valuable,
but would need a thorough and
systematic approach. (The best creel study to date by MRAG
apparently also suffered from
considerable under-reporting.)
Yacht fisheries
Yachts are permitted to fish for personal consumption and on
application for permit to visit are also
given digital form for reporting their catch this would be
reported direct to MRAG. There is also a
folder and pile of blank forms in Salomon, but this was
gathering damp and dust and had no
completed forms.
On visiting yachts UK Customs generally do not search boats, but
would look for signs of illegal
activity (spearguns, coconut crabs, dive gear) which could then
lead to more complete search. They
do sometimes ask them about fishing but not in any detail.
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17
A detailed description and summary of the information from the
DG and yacht based fisheries
return forms should be obtained. We need to consider how to
improve returns on the shore (and
possibly yacht) fisheries. There would be great value in
commissioning a new creel survey to
assess these fisheries.
Surveillance and capture
Operational details of the fishery surveillance and capture
activities and capabilities have been noted
by the CSA, but, due to the sensitive nature of such
information, they are not presented in full here.
Earlier public reports detail the only Sri Lankan vessel
captured in 2013 (BIOT Government, 2014a)
and suggest that this single capture may be part sign of a
decrease in IUU fishing resulting from both
UK patrols and Sri Lankan measures to control flagged vessels.
There have, however been 2 arrests
already in 2014 which are still sub judice.
With Sri Lankan vessel arrests the vessels are taken into DG
where the catch details are documented,
prior to burial (see waste). Recently a new approach has been
developed vessels charged and are
taken to DG where the catch is offloaded, but they are then
allowed to return to Sri Lanka while the
owners are prosecuted in absentia and fines are pursued through
bilateral and multilateral
agreements (BIOT Government, 2014a).
MRAG have also provided a report of an IUU incursion by a
Taiwanese longliner in 2013 which was
observed, but refused to co-operate, abandoning lines in BIOT
waters. There has been some
cooperation from the Taiwanese government, within their own
legal parameters, and the vessel was
tried in absentia and subject to a 195,000 fine plus 5000 fees
it offered 30,000 in settlement
but this has not been accepted and the case continues (BIOT
Government, 2014b).
It must be remembered that with such IUU fisheries, observance
and capture can be highly
influenced by both the skill of the patrol crew, the avoidance
skills of the IUU vessels, but chance
also has an influence on the total numbers of captures. The Sri
Lankan vessels are small, but are also
slow and have no radar, making interception and capture more
likely. By contrast the tuna vessels
are a considerable challenge, as witnessed by the evasion of the
Taiwanese vessel in 2013. The main
tuna season is Oct-Feb, and there are regular patrols, but the
large radar horizon and the speed of
these vessels makes capture a challenge.
The FPV may already be having a valuable impact on the illegal
demersal fishing, although it is
difficult to quantify this success in terms of the proportion of
IUU vessels that are captured, or the
deterrent value. There is a far greater challenge to impact
possible IUU tuna catch. For both
fisheries there is a need to try and ascertain the levels of
illegal fisheries irrespective of capture.
Following discussions with BritRep, XO and SFPO, there appears
to be some possibility for more
engagement with DG in surveillance.
BritRep has established protocols to encourage reporting on the
presence of possible IUU vessels in
BIOT waters by incoming and transiting military and civilian
vessels and planes. In some cases
BritRep and/or SFPO could advise them on course to maximise
coverage or complement existing
surveillance. Not all observations could be acted on, but
proportion of illegal vessels of those acted
on would be indicative of pressure. Is there also possibility of
using past satellite imagery to look at
vessel traffic in Chagos waters to ascertain use in different
sectors.
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18
The current SFPO was widely praised for his abilities in
patrolling and interception, with an
observation that such skills are not always expected, and yet
are clearly more important than the
now redundant abilities of fisheries management.
It might be possible to improve policing with a more
co-ordinated approach and some sharing of
surveillance data between BIOT officials and their contractor
(MRAG) in real time. A previous MRAG
SFPO had shared six-hourly position and activity reports from
the FPV for 4 months 2013-14. Plotted
these show areas of patrolling and linked observations of FADs
and ship interceptions. The sharing of
such information is currently not in the job description of the
SFPO and there may be concerns of
interference or even conflict of interest as SFPO is employed by
MRAG. On the other hand such
information is clearly valuable and MRAG also holds presumably
very large volumes of such
surveillance information over many years and these should be
made available to BIOTA for future
use in a broader review of surveillance approaches and for
possible sharing with other/future parties
being engaged in this work.
In the short-term there could be value in encouraging dialogue
and collaboration between MRAG
and the BritRep/BIOT team on-island to encourage some further
data-sharing around surveillance.
There were also discussions about other novel surveillance
approaches:
Placing web-cams on the islands for surveillance
Aerial surveillance with drones
Marine surveillance with Remote Operated Vehicles
There could be security concerns with deployment of these
active, but unmanned approaches,
however these would be surmountable if BIOT authorities were
linked to surveillance and able to
develop the policy. UK and US military could remain fully
informed and could perhaps influence such
work to avoid sensitive operations.
The above came from a real interest in a more formal engagement
of Royal Navy in surveillance.
They are expert at it!
The BIOT patrol vessel is performing an excellent task for the
resources available to it, however
there are significant limitations in its capacity. This is due
to its size and speed, but also to the
multiple requirements of its mission, which include patrolling,
science expeditions, customs and
immigration, Chagossian cultural visits, the resettlement
feasibility work as well as official visits from
CSA and other government representatives.
In making plans for ongoing and future surveillance it would be
valuable to have a rational
discussion with all players on vessel and surveillance needs,
science support and possible options.
There are clearly different opinions, but also challenging
budgetary constraints.
Shark human interactions
A recent fatality at the popular beach and marina has led to a
number of regulations on swimming
(in pairs and during daylight hours). I would be interested to
know if there has been a more
thorough review of this. One attack of this nature in 40 years
is not a high rate, and there probably a
risk of excessive caution, rather than a need for tighter
regulation. The impact of reducing access to
the water would perhaps be more on morale and welfare, however I
do feel that maximising safe
access to nature by island residents is an important means of
raising environmental appreciation and
awareness. It is perhaps worth pointing out that reef sharks are
a major draw for tourism in many
coral atolls, including many popular beaches where small reef
sharks are abundant (Anderson and
Waheed, 2001; Gallagher and Hammerschlag, 2011; Vianna et al.,
2012).
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19
Even so, there may be a place for some improved information and
management amendments to
reduce risks of shark-human interactions, while maintaining or
even enhancing overall access to
the lagoon and these should be further investigated. For
example it would make sense to separate swimming from areas
where coastal fishing is popular and from the dock where
fish
are landed. Measures might be put in place for greater
separation between boat-based fishing areas and areas used
for in-water recreation. It would also be valuable to
develop
some posters to explain the risks (for example reef sharks
are
non-aggressive and generally safe but: non-fatal bites have
been associated with presence of food in the water, typically
the
threat is greater if water is murky and in shallow water
where
sharks may be feeding, and where only part of a body is
visible
to them (typically ankles)). Actions on this front should be
undertaken with the participation, and funding, of US MWR.
Similar consideration needs to be given to Salomon anchorage
area. Reef sharks are permanently present under the yachts.
Better information might help to reduce the residual risk of
accidental attacks.
Two small lemon sharks feeding in knee-deep water in the eastern
lagoon area near Barton Point.
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20
Biodiversity Conservation
Habitat Restoration
PWD have a formal policy of replacing every tree cut down with
two planted. They apparently
greatly exceed this ratio at the present time. Previous CSA made
the point that these hardwoods are
far more water efficient than coconut forest so there could be
significant water recharge benefits in
such activities.
From a habitat restoration perspective, three small sites have
been a focus of restoration, largely led
and encouraged by Major Peter Carr, former XO. I visited the
southernmost two of these briefly and
made a more thorough tour of the furthest site beyond Minni
Minni, (Barton Point Hardwood
Restoration Site). In all sites the original donkey fencing is
somewhat dilapidated. There is quite a lot
of hardwood growth, including a good variety of native trees:
Intsia bijuga, Barringtonia asiatica,
Guettarda speciosa and Morinda citrifolia were among those
identified
Damaged fencing in the Minni Minni Plantation
Left to right: Guettarda speciosa, Intsia bijuga and Morinda
citrifolia
There is a need to track down any reports covering overall
policy, species planted, area covered
(maps?), techniques deployed; follow-up or proposals for
follow-up. These should be used to
provide advice on future efforts.
There is a possibility of engaging existing ground-staff and/or
volunteers to extend this work.
Current grounds management in this area is poorly planned and ad
hoc, so such guidelines could
yield significant benefits at no cost.
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21
There may also be a need for a field based review of these
projects. It would be valuable to know,
for example, about the relative success of different native
species, the importance of nursery
saplings versus natural regeneration, the threat of donkey
grazing, the effectiveness of different
measures, including fencing, or coconut cordons. Equally
understanding the relative costs and
benefits of different approaches would be helpful if natural
regeneration is only slightly slower, but
comes at a fraction of the cost of nursery rearing, planting and
fencing large plots it might be
possible to progress restoration over much wider areas for
similar costs in terms of funds or labour.
In the absence of more information I would suggest that the most
effective and rapid gains around
restoration would be to encourage natural regeneration in areas
of mixed coconut and other native
forest areas where there are already saplings. Here efforts
could focus on removing coconut palms
and using trunks, coconuts and debris to build cordons around
priority native saplings as protection
against donkey grazing
The previous CSA also spoke of wetland restoration I did not
follow up on this, but did note that
one of the artificial ponds adjacent to the airport had been
drained for clearance and re-filling. It
would be useful to know more about this, and its conservation
relevance
Invasives
Currently on DG the regular invasive controls are on rats, cats
and chickens. Chickens are perhaps
gone. An environmental officer on DG estimated 8 individual cats
have been seen and extrapolated
from this to perhaps 20 in total on the island. Rats remain
abundant, though less so downtown due
to ongoing poisoning. Brown and black widow spiders are spotted
on occasion inside buildings,
when this happens a team is sent out to remove them with
insecticides. I am also aware that some
training is run twice a year on the brown tree snake risk for
staff likely to be handling cargo from off-
island. There is an ongoing study of rat eradication, with
possible idea of DG eradication programme,
it would be useful to know more about this.
Invasive plants are not being actively managed except as part of
other ongoing site work which can
include quite thorough removal of Ironwood and Mimosa.
No other invasives are actively pursued. Britrep suggested it
would be helpful to have an official list
of pest species to guide removal policy.
Rat Eradication
A brief circumnavigation was made of Ile Vache Marine (scheduled
for eradication in July). Some
cross-island transects have already been cut and locations for
others are prepared. This looks a
highly manageable island for the work in terms of island size
and vegetation.
Public engagement
One of the most important tools in effective and ongoing
environmental protection is the
engagement of local people, in this case island personnel. If
people are able to enjoy their
environment it is much easier to engage them in caring for
it.
Many island personnel are already highly active in the natural
environment, through activities such
as cycling, snorkelling, sailing and fishing. It is also highly
positive to note a number of activities that
do encourage or foster such engagement, including:
the biannual tip to tip bike race,
the viewing platforms at Turtle Cove,
18 miles of jogging/walking and off-road biking trails
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22
Earth Day (April) and Sea Turtle month (November)
Fun runs
Weekend bus-trips to the Settlement,
ongoing turtle monitoring work,
beach cleaning exercises (which, one might argue are a product
of good public engagement)
there is also a proposal from MWR (Morale Welfare and
Recreation) to develop a forest trail
for access by solar charged Segways,
To further benefit from this kind of outreach there is a need
for more direct communication and
education and there could be considerable advantage in
development of more signage or other
more active communications. The materials (postcards, booklets
and information sheets) produced
by CCT are certainly a positive contribution, but are probably
somewhat hidden from most people. It
would be valuable to encourage direct communications through the
radio/TV, and to strongly
encourage visiting scientists to give presentations. (I did
offer and there was enthusiasm, but no
time to organise as BritRep was off island during latter part of
my stay).
Signage like this at Turtle Cove presents an important
opportunity to reach out to island residents and engender greater
support for environmental issues on Diego Garcia.
Boats in northern atolls
While I only joined a customs visit to one yacht, in general the
customs visit consists of a brief
passport and permissions check. It might be valuable to use this
visit to remind yachts of the rules,
encourage them to return the fisheries forms and of course to
keep an eye out for any evidence of
rule breaking.
Waste
Yacht waste is collected from Boddam and Ile de Coin. On the
former the bins were overflowing and
one bag was on open ground (and had been ripped open by crabs).
In all cases the trash appeared to
be uncrushed and could have occupied half the volume.
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23
Waste on Salomon (left) and on Boddam (right) bins were full,
but much of content was uncrushed plastic bottles and cans, with
excess dumped on the ground in breach of regulations
Current signage for waste disposal on Salomon unreadable, and
not encouraging
It would be valuable to create some clearer and more forceful
(and explanatory) signage to
encourage correct behaviour. This is probably a task that needs
repeating on occasion as signs will
fade, become outdated or simply look old and be ignored. Where
there is evidence or reporting
of particular culprits these should be followed up, at lease
with an expression of concern.
Anchors
Over the years, concern has regularly raised about anchor damage
to the sea bed in the northern
atolls. More recently boats were restricted to five mooring
sites where they can moor or anchor.
We dived under two yachts but unfortunately in both cases the
yachts were attached to fixed
moorings so anchor damage was minimal. I am not clear whether
these moorings were installed by
BIOT, or with BIOT approval (historically there were demands for
such moorings, but concerns were
also raised over insurance implications if BIOT put these
in).
Undamaged coral gardens at 5-7m depth in Salomon Lagoon, showing
the high diversity and complexity of reef structure (rugosity).
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24
This area really is an extraordinary coral garden with a high
species diversity and very high rugosity
(structurally complex), making it highly vulnerable to anchor
damage. There were certainly quite a
number of small patches that had been smashed, possibly by small
anchors from dinghies coming to
Boddam from yachts further offshore. Under the second mooring
there was a more extensive plain
of flattened substrate, but this appeared to be associated with
a shipwreck.
The unusual and highly diverse nature of the Salomon Lagoon
gives it a very high conservation value,
already much commented on. I am, however, unaware of whether
this importance is contiguous
across the lagoon, or hence of the relative importance of this
anchorage site in relation to the lagoon
overall.
It would be valuable to obtain a more detailed understanding
(either from data already gathered
from the ongoing science expeditions, or from a new survey) of
the distribution of important
benthic habitats across the wider Salomon lagoon, and perhaps to
undertake a (necessarily more
sparse) survey of seabed features in Peros Banhos in order to
ascertain the relative importance of
anchorage sites.
The observations from Salomon also underscore the importance of
fixed moorings.
Patches of damaged coral in Salomon linked in the vicinity of
the fixed moorings. Damage like this could be created by a single
anchor and chains in a matter of days.
The FPV anchors with large chains across the archipelago. It was
noted that the ship has a number of
fixed locations marked on its charts where it always anchors and
this is doubtless important these
are effectively sacrificial sites needed to support the work of
the FPV.
There would be some value in detailing the exact GPS locations
of these anchorages for any
change of personnel or for use by other licensed vessels to
ensure that damage remains
contained.
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25
Science and observations
Facilities
At present a large amount of science kit (mostly Darwin Project)
is being held in small air-
conditioned store near the marina and funds have been made
available to convert a larger space in
part of the vehicle maintenance area of UK forces. This looks
like an excellent space. There is also
already plumbing and I suggested that they consider using the
end wall as a small lab-space which
could be immensely valuable to future expeditions. This was felt
to be an easy adaptation.
Coastal erosion
Aside from the Moffatt and Nichol report, which deals with the
inhabited area of DG I am unaware
of other studies on erosion across the rest of DG, other than
the recent debate between Sheppard
and Hamylton on DG (Hamylton and East, 2014; Sheppard, 2014).
While I did make personal notes of
erosion/deposition, it is important to note that such
observations have little value in ascertaining
overall processes around the islands.
Clockwise from top left: Erosion on E Eagle island, showing
collapse of former settlement buildings in to the sea; erosion on
the protected lagoon shore of Middle Brother; erosion of lagoon
shore in Diego Garcia with eroding dune scarp; recent colonisation
of newly deposited sand on Ile du Coin, Peros Banhos (note that
these are very young plants could be less than one year old and
this may not represent any permanent new ground on the island.
Overall erosion is widespread on many islands including: W
Eagle, large parts of Middle Brother,
parts of N Ile de Coin (lagoon side), N shore of Moresby (ocean
side), and outer margins of S and E
shores of DG. In all or most of these cases the erosion is
undermining mature trees, suggesting that
this is novel. By contrast deposition is rarer quite a number of
islands on Perhos Banhos showed
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26
sand banks extending to north and south or on most sides of Ile
Vache Marine, however the lack of
any substantial colonisation suggests that such extensions are
probably seasonal (confirmed by
SFPO). There is some new colonisation by coconuts and Scaevola
on the W end of Ile de Coin.
On DG, Eagle, Moresby and Ile du Coin there is clear evidence of
over-topping of some island
margins, visible in terms of debris transported inland.
Over-topping is a natural process on atolls and
indeed is a necessary part of island formation and so it would
not be advisable to use this evidence
as proof of a growing threat of sea level rise or of risk of
island loss. At the same time, inundation
and erosion will be the mechanisms by which sea level rise
begins to impact islands, along with the
salinization of freshwater lenses.
The most important message from these observations is that there
is an urgent need to get
observations like this onto a solid science footing. Atoll
islands are naturally highly dynamic. Sea
level rise is a clear and important threat, but will not need to
loss of territory in all places. A
reliable long-term study, using air photos for recent history
and setting baselines for even more
detailed annual assessment could be critical for long-term
planning, both for conservation and for
current and future human use of the islands. Such a study should
be led by those with an expertise
in tropical geomorphology as suggested in Hamylton and East
(2014).
Fishing impact
There is legal fishing in DG, from the yachts, and from the
fisheries patrol vessel. The yachts are
probably having a localised impact in the lagoon (no large
groupers were seen in the lagoon dive
there). In DG there is no information regarding the large
shore-based fishery. The FPV is not a large
ship and is patrolling a very large ocean, however concerns have
regularly been raised by scientists,
both that there may be some impact, and that this is not sending
out a good signal in what is
regularly described as a no-take MPA. Currently fishing from the
FPV, even in the strict nature
reserves, is legal. While there would be only weak ecological
justification for closing all fishing
from the FPV, there would be some value in establishing some
additional limits, with the closure
of some areas. The primary aim of such an approach would be to
curtail any future expansion, but
also to signal the importance of no-take in Chagos and to ensure
that some locations are truly
without any fishing impact. Closing all fishing from the FPV
would probably be counterproductive.
Mangroves
There are two known areas of mangrove in the Chagos Eagle and
Moresby Islands. Both have been
described by scientists in the past as threatened with loss
through overgrowth by coconut, parasitic
plants or drying out and there have been calls for management
intervention.
The two communities are very different:
on Moresby the mangroves we visited were growing around two,
interconnected,
mangrove-fringed lagoons that have no direct connection to the
sea. These give way to
mixed forest on one side and to Pemphis acidula a rocky berm and
then the N coast.
Although they are only a few metres from the sea in places, this
higher island margin, with
quite a lot of rocky debris, is a permanent barrier which would
only be overtopped by storm
waves. Subsequent to this visit SFPO has returned to these
mangroves and confirmed that
the mangroves are intertidal, drying at low tide, and with water
bubbling up through the
substrate as the tide turned. During our earlier visit the water
in this lagoon was brackish
rather than full salinity, showing that is it fed both by the
sea and the freshwater lens. Trees
were large (some reaching 4m), but none were observed in flower
and there was apparently
no recruitment. A few trees were dead or dying, but the majority
appeared healthy.
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27
Although this is a (heavily!) ratted island the mangrove was a
rich nesting ground for red-
footed boobies even on branches at low elevations over the
water. Presumably they are
benefitting from the waterlogged substrate which might prevent
rat predation.
Top: Mangrove lagoon, Moresby Island, Peros Banhos Bottom:
Mangrove community on Eagle Island, growing amongst grasses and
some coconut trees (left) with occasional patches of denser
mangrove cover (right)
On Eagle the mangroves are more clearly inland and while the
site is usually (SFPO pers
comm) waterlogged we visited at low tide and it was largely dry.
The mangroves are quite
extensive but mostly in a number of mixed associations with
coconut, grass, fern and some
hardwoods. Towards the central more open area many larger (4m
plus) trees were dead or
dying, but the cause of death was unclear, it was not
overcrowding, and there were a
number of dead or dying coconuts. In one area apparently healthy
low-stature bushes (2m)
were in a solid formation, but nearby similar trees were being
strongly overgrown by the
parasitic dodder (Cassathya). The latter is a native species,
however and this is presumably a
natural phenomenon. Unlike Moresby, quite a number of the
mangroves were flowering and
there was recruitment.
From the observations of the mangrove forests it is not clear
that any urgent management
intervention is needed, but ongoing scientific observation and
perhaps more detailed mapping
and description would be valuable
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28
Reefs
Dives and snorkels were undertaken at eight locations. There is
enormous variation in the reef
communities with depth and location, and much of the highest
diversity, coral cover and fish
abundance is located in waters 5-10 depth (beyond easy
snorkelling range). Given that coral reefs
are among the most important habitats in BIOT it would be
difficult for the CSA to fully assess
ongoing science or raise key issues without at least some recent
experience of these habitats and so
it took some organising to be able to dive, it was important for
the CSA to be able to see these.
The CSA kept basic site descriptions and these have been used to
develop the following comments:
Coral condition and disease
Initial observations from the leader of the recent science
expedition warned of a widespread loss of
Acropora plate corals and some disease. Coral disease appeared
to be widespread although was very
largely associated with plate Acropora corals. These corals are,
or were, dominant in many reefs,
perhaps more so than they were prior to the 1998 coral death
event. They are generally rapidly
growing species that filled large areas of reef tract.
Disease and recent coral death was mostly confined to plate
Acropora, but this partially bleached, partially dead massive coral
was photographed in the lagoon near Barton Point
There was variation in die-back, and of course it cannot be
assumed that all dead corals have
resulted from disease, but in some areas, notably off the west
coast of Eagle Island a majority of
coral was dead and new recruitment was relatively low.
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Detailed reports on disease are expected shortly from the most
recent science expedition and
should be given close attention.
Fish and shark populations
Fish stocks appeared healthy, with large numbers of groupers and
snappers in most sites. There was
possibly some evidence of fishing pressure in Salomon Lagoon and
a slight indication that large
grouper numbers may have also been a little reduced on the outer
slopes of S Ile Anglaise which is
likely to be a popular fishing location for yacht-based
fishers.
Sharks were abundant on most dives. Clearly the sample was too
small for any scrutiny, but these
included 5 common reef shark species (whitetip reef, blacktip,
silvertip, grey and nurse sharks, with
2 lemon sharks observed feeding in DG Lagoon).
Lagoon reefs
Lagoon reefs were visited in 3 very different settings. Ile
Vache Marine (very brief snorkel), which is a
somewhat exposed lagoon/fringing reef had very high cover of
live plate Acropora with little disease
observed. Salomon lagoon has remarkably high coral cover, with
considerable diversity (at least of
coral morphologies, experts are needed to comment on species
diversity). Anchor damage was
present, but not widespread in the area visited (about 300x25m).
Finally a snorkel over the back reef
areas towards the mouth of DG Lagoon (Barton Point) showed an
extensive area of shallow reef
dominated by bare rock with algal turf) and some larger, stable
areas of rubble, but with numerous
massive Porites-like corals, forming fields of micro-atolls in
shallower areas, and some robust
branching colonies (Pocillopora-like). This DG reef was probably
impacted by bleaching some time
ago (1998) explaining the branching coral rubble, and also the
recovering growth forms of some
massive corals.
The healthiest plate Acropora colonies were observed near Ile
Vache Marine, but even here there was disease and some areas of
substantial die-back
Turtles
Green and hawksbill turtles were observed in multiple locations
in the Northern Atolls and are of
course still abundant in Turtle Cove. Nesting tracks were
observed in multiple locations around DG,
Nelson and Ile Vache Marine. It is now over 40 years since
turtles were harvested and 18 years since
Jeanne Mortimers extensive island-by-island assessment of
nesting (Mortimer and Day, 1999). It
would be valuable to know if the science is delivering any
information on change in nesting rates.
Island erosion and beach litter are both likely obstacles to
nesting in a few places, with the steep or
vertical sand or root margins of eroding shores being perhaps
the greatest obstacle, but it seems
unlikely that these would be limiting nesting capacity. In 1996
Mortimer and Day estimated length of
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suitable nesting beaches for most islands in Chagos (Mortimer
and Day, 1999): it would be
valuable to know whether this extent is being reduced by changes
in island morphology.
There is a strong commitment from the current XO to supporting
turtle monitoring which is being
linked directly to the academic research community (see
below).
Citizen science and conservation
It is clear that engagement of DG personnel in conservation work
is providing science and
environmental benefits notably beach cleaning and turtle
monitoring, but also past efforts at
habitat restoration. I would include in this the important work
undertaken by UK personnel on the
northern atolls such as beach clearance and rat eradication. As
mentioned this sort of engagement
produces benefits to the environment in other ways, notably
raising awareness and increasing
concern for protecting the environment, but also in terms of
morale and welfare. There is clear
enthusiasm on the part of senior personnel on the island, and
indeed a long history of such
enthusiasm and engagement both at levels of senior officers and
in terms of volunteers from across
the military and civilian personnel from all nationalities. A
significant limitation on this work is the
capacity of key senior personnel, who have to fit such work
around what are already highly
demanding schedules.
It would be useful to develop a summary of the contribution of
this work to date, and to review
and describe the range and potential for future citizen science
work. This might serve to
encourage ongoing and new efforts, and aid the transfer of
skills and knowledge to new
personnel. This might include species monitoring (plants, birds,
turtles, coconut crabs, invasive
species); beach clearance and reporting; invasive plant removal,
tree-planting and even marine
science, from snorkel, fishing-based sampling or even diver
surveys. Diving by personnel on Diego
Garcia has been allowed in recent years, however it is not
strictly permitted as diving is meant to be
for science or maintenance/infrastructure work only.
Establishing a simple programme of citizen-
science diving would help legitimise any restoration of diving
activity and could be very valuable.
This would need careful discussion and thought, but there are
many programmes available which
allow for training and delivery of simple survey data by
non-scientists on coral reefs.
There has been some discussion about the use of a 6-month
volunteer/low paid intern to run basic
science around DG this could include supporting citizen science,
but also some basic ongoing
science observation, conservation work including restoration,
and community outreach. It would
need to be funded, but it could be a valuable opportunity to
increase some science reporting to the
CSA and the FCO, to other scientists and NGOs. They may also
further enable the ongoing citizen
science work that continues to be supported by BIOT personnel.
BritRep expressed concern about a
permanent presence of professional civilian scientists due to
costs/logistics of running this with
current personnel.
Expanding the baseline
In so many settings there is a need to understand environmental
settings around Chagos more
broadly in terms of geography and discipline (ecology,
oceanography, geomorphology),
particularly in areas where there has been little or no
observation to date (both in terms of
geographic location and key disciplines). This detailing of
baselines is not necessarily the top priority
for academic research which favours detail, novelty and change,
but is critical for providing the
comprehensive baseline on which change can be more certainly
understood. Mention has already
been made of the need for detailed historical to present day
geomorphological studies, and in
establishing baselines against which to measure future patterns
of island dynamics.
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31
As ecological examples, the reefs encircling DG are unstudied
beyond a handful of point locations at
the northern tip. Likewise I believe the extraordinary diversity
on the seabed of Salomon Lagoon is
only really described from the southern end, the area most
impacted by anchors and (presumably)
pollution. In both cases we have no idea of the
representativeness of these known areas, we are
unable to judge if the protection (DG) or sacrifice (Salomon
anchorages) are well placed. Further we
would be unable to recognise any major changes to these systems
resulting from human or natural
perturbations.
Some of this science, is of particular relevance for human
needs. On DG the long-term stability will
undoubtedly benefit from thriving reef communities generating
new sediments and providing critical
natural breakwaters (Ferrario et al., 2014). There are also
implications for any considerations of
resettlement beyond Diego Garcia.
A science plan already exists and work is underway to develop a
conservation and management
plan. While there is overlap, it is appropriate that these
should be maintained as distinct outputs.
Critical to such planning tools is a vision of need and
prioritisation, particularly to guide the
necessarily limited budgets of the BIOT Administration, but also
to help in the assessment of
proposals for other visiting scientists and the potential
engagement of new partners in
conservation work.
In developing management plans and science plans there is also a
strong need for a centralised
data store for environmental information on Chagos, including
findings from the science, from the
fisheries patrol, and from non-sensitive environmental studies
around DG by military and
contractual visitors. As much as possible should be made open
access, with data-sharing protocols
to be determined and agreed to as an a priori requirement for
all those working in Chagos. This
may be something the CCT and science leaders have already been
pushing for.
Science and conservation work are both growing in quantity and
scope throughout the Chagos.
Funding for such work is also growing and diversifying, from
academic, philanthropic, NGO,
government and other sources. This is to be welcomed, but with
this is an ever growing need for a
broader vision.
Closing comments
At the end of this first formal visit as CSA to Diego Garcia and
the northern atolls it is important to
stress the positive impression given by all those I met and
worked with. Diego Garcia is a very large
military facility in a remote and fragile environment and the
efforts that are being undertaken to
preserve and indeed enhance this environment are impressive. The
only counter to this is that they
should be. The BIOT is almost unique in the world now, in terms
of its large area of healthy coral
reefs and undisturbed coral islands. Its importance will likely
only increase relative to the ongoing
declines in many other tropical reef environments world-wide.
There is thus what might be seen a
need or a duty to look after this environment above and beyond
the normal best practises. An
alternative wording might talk about an honour and a privilege
to be able to undertake this
stewardship in one of the worlds most pristine environments. In
no place was I given the impression
that efforts are slacking, or that weaknesses are being
deliberately ignored. I was given full access
and encouraged to ask questions and to inspect wherever I
wanted. This open-ness is most
impressive and welcome.
I have of course raised quite a number of issues, listed at the
start of this document, and in bold-
typeface throughout. Key among these are the need to better
understand the possible impacts of
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32
treated wastewater disposal directly onto the reef; the impacts
of recreational fishing around DG
but also from the yachts in the northern atolls; the
possibilities of improving surveillance and
capture through co-ordination with BIOT personnel and over the
longer term through new
approaches. There is a need for new baseline science research,
and for much greater sharing and
access to data describing the environment around BIOT; there
could also be considerable benefits
from better environmental communications and efforts to engage
and educate both personnel in DG
and visitors to the northern atolls.
These and the full list of comments need to be understood in
terms of the positive impression
overall. They are intended to help to push, steer and guide
towards greater improvements and to
avoid present and future risks.
Acknowledgements
I am most grateful to the BritRep and XO for their support and
enthusiasm to help me understand
the islands and all the issues which might impact the
environment. Thanks also to the US
Commanding Officer and to the staff of PWD for the invaluable
discussions and the access and
guidance around several key facilities.
For the visit to the northern atolls I am grateful to the
Captain and crew of the Pacific Marlin and of
to the SFPO for his guidance around islands and for sharing his
broad ecological and fisheries
knowledge. Many thanks to my two dive buddies from the Royal
Marines. Thanks are also owed to
the science expeditions for allowing us to use dive tanks and a
compressor to enable this to take
place, and to the BIOT Dive Club for the loan of equipment.
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