Annex I
DEFRA REVIEW OF NON-NATIVE SPECIES—MARINE
ISSUES MARINE CONSERVATION SOCIETY RESPONSE—MARCH 2004
The Marine Conservation Society welcomes the
working group report, and any advance of policies related to non-native
species invasions into the UK.
1.6 Geographic area of consultation
Transfer of non-native marine species between
UK and Eire is more likely to be rapid and serious in the marine
environment than in the terrestrial environment because of the
fluidity of gamete transfer in the aqueous environment. MCS recommends
that an overarching group be convened to address issues related
to marine invasions of non-native species that incorporate the
British Isles, Northern Ireland and Ireland, and not just the
area of the British Isles (as recommended by the working group).
1.5 Spread of disease
Exotic animal diseases are a concern for the
marine aquaculture industry. Importation of farmed stock to the
UK (be it fish or shellfish) can also introduce unwanted disease
and parasite infection, which can be rapidly transferred to the
captive farmed stock, and possibly to wild individuals near to
the cages, which may not be resistant to non-native strains of
particular diseases. MCS recommends that introduction of stock
from overseas is limited or eradicated in order to prevent potential
contamination of indigenous populations.
2.0 Organisational structure
If an overarching body were to be established
to mitigate against non-native species invasions, MCS recommends
that a separate specialist sub-group be formed to work specifically
on marine invasions. Marine non-native species invasions require
a completely different set of control systems, are ecologically
separate, have separate introductory pathways, and have separate
legislation associated with them compared to terrestrial species
invasions.
2.3.3 An audit of gaps in monitoring of non-native
species
MCS supports the need for an independent audit
of the gaps in capacity to monitor non-native species. An audit
of gaps in monitoring marine non-native species would likely identify
the need for considerable investment of resources to support the
following:
— The screening of thousands of tonnes
of ballast water (and ballast water sediment) from the commercial
shipping industry (see new IMO convention). Ballast water screening
would need to be carried out by specialists in marine taxonomy—a
costly prospect in terms of use of the current number of UK taxonomic
specialists, and the number that would need to be trained in order
to carry out any form of assessment on a UK (and Ireland)-wide
basis.
— There would be a need to monitor
the aquaculture sector, and the aquarium industry for disease,
parasites, and "escapes" of farmed stock into the wild
marine environment.
— Benthic non-native species monitoring
should also be instigated near ports where exotic species may
be able to gain an ecological foothold if discharged by accident
or intent from ballast tanks. This would require considerable
investment in subtidal SCUBA-based surveys. These surveys could
be incorporated into SAC monitoring wherever appropriate, and
in any publicly funded survey programme (for example as part of
an EIA for a harbour development). Without this integrated approach,
practical application of this work could be expensive, and would
be particularly time-consuming. MarLIN (www.marlin.ac.uk) and
Seasearch (www.seasearch.org.uk) have already introduced a "selected
underwater species" guide for volunteer recorders, which
asks members of the general public to record three marine invasive
species. This scheme could be promoted to a wider UK audience
if additional funding was made available, and the list of non-native
species should be expanded.
7.0 Control measures of established populations
Prevention in the marine environment is also
of considerable importance—factors that need to be incorporated
into management decisions for established non-native species are:
— Life history of the species—for
example, is the species a broadcast spawner which can release
spat/gametes to a wide area of coast? If this is the case, the
distribution of animals around any surveyed population could be
considerable.
— Level of fecundity—are the
species particularly fecund and able to release a large volume
of eggs/spat?
— Spawning season—what is the
season of spawning? If eradication can be carried out prior to
spawning season for the species, there is a greater chance of
permanently eliminating the population.
— Habitat of the invasive species—does
the species colonise reef, sand, or mud areas, and if so, what
are the consequences for indigenous species.
— Ecological damage—are they
outcompeting another indigenous species and/or habitat? If so,
what are the knock-on consequences of this dominance to native
species? Does this lead to changes in food web structure? For
example, the Caribbean Caulerpa taxifola invasion of the
south of France, California and South Australia has led to considerable
loss of seagrass habitat. The Chinese mitten crab (Eriocheir
sinensis) has eroded considerable areas of estuarine river
bank through its burrowing activities.
— Economic damage—will the species
conflict with various different economic sectors of the maritime
environment? Caulerpa taxifolia has affected the transport,
commercial and recreational fishing industries (but not in the
UK as yet). The Chinese mitten crab has affected the fishing industry
and water companies in the south east of the UK.
MCS supports the idea of "rapid response"
eradication or control mechanisms being put into place in areas
of either high biodiversity, or in areas that could potentially
be damaged if a non-native species were to become established.
An Environmental Sensitivity Map (ESM) could be established for
this purpose based on a number of ecological criteria combining
elements of rarity of species, biodiversity, and likelihood of
invasive species becoming established. This map could be used
as a reference for future invasive species management.
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