PLANNING FOR SUSTAINABLE GROWTH IN THE ENGLISH AQUACULTURE
INDUSTRY
Response on behalf of the Atlantic Salmon Trust, the Wild Trout Trust, the
Angling Trust etc
We are responding jointly to this consultation paper.
We welcome the statement in the Foreword by the Parliamentary Under-Secretary
for Natural Environment and Fisheries that the Government, while encouraging the
development of the aquaculture industry, wishes to protect the health status and
conservation of UK farmed, wild migratory and freshwater fish, and shellfish. In view
of this, we are surprised that no organisations concerned with the conservation of
migratory and freshwater fish, or with angling, were involved in, or consulted by, the
Consultation Group, or were even sent the consultation document. We are even
more surprised that the Environment Agency is not shown as a member of the
Consultation Group, given the Agency’s regulatory role in connection with the
protection of the freshwater environment, its duties as Competent Authority for the
implementation of the Water Framework Directive and its statutory duty to maintain,
improve and develop salmon and freshwater fisheries.
This response does not attempt to address the questions in the consultation
document, as these are not relevant to our principal concerns; indeed, the only
questions on environmental protection (Qs 4 and 5) treat this solely as a potential
barrier.
We agree that a sustainable aquaculture industry could play a useful part in
supplying UK consumers with fish and shellfish. However, the consultation paper
makes no attempt to define what the criteria for a sustainable aquaculture industry
should be. It simply asserts that aquaculture’s need for good quality water gives the
industry a stewardship role in assisting to protect England’s aquatic environments. It
says virtually nothing about the effect that aquaculture sites themselves can have on
water quantity and quality and on the wider environment through effluent, water
usage, escapes and the transmission of disease and parasites. Although it admits
that aquaculture does have environmental impacts, it claims that these ‘are
minimised by undertaking impact studies when the farms are established, and
ensuring that the farms do not create long-term damage to the environment’. This is
very far from being the case.
Open–cage salmon aquaculture provides a clear illustration of the environmental
impacts of fish farming. There is compelling scientific evidence that sea lice
emanating from salmon farms can pose a very serious and dangerous risk to wild
migratory salmonid populations. In some areas, escapes from salmon farms also
pose a significant risk to the genetic integrity of salmon populations.
In England, most fin-fish aquaculture involves freshwater flow-through systems, but
these also have environmental impacts. There has been surprisingly little research
into the impact of fish farm effluent on the aquatic environment, but where studies
have been carried out in other countries, effluents from fish farms have
been implicated in changes to the abundance and survival of juvenile salmonids. For
example, rainbow trout farms in Brittany were found to have had significant effects
on wild juvenile Atlantic salmon, with a significant reduction in salmon parr
abundance evident for several kilometres downstream of the farms1. Fish farm
effluents have also been found to have an impact on other pollution sensitive fish
species and on macro-invertebrates. One study, for example, found that macroinvertebrate richness and abundance of sensitive taxa (mayflies, stoneflies, and
caddis flies) were reduced downstream of a fish farm and pollution-tolerant noninsect taxa (isopods and gastropods) increased2.
Flow-through systems divert water from water courses, leaving depleted reaches;
lower than mean flows will alter the morphology of the stretch, so impacting the
species living there, and can create barriers to fish and invertebrate migration.
We therefore disagree with the consultation’s scene-setting descriptor of the
“minimal freshwater requirement” of sustainable aquaculture, certainly in the case of
flow-through systems – there are many examples around England of fish farms using
very large amounts of water. Even though such water is eventually returned to the
river, the environmental impact can be considerable. One example, on a southern
English SAC river, has a consented abstraction of 130 million m 3 per annum, taking
66% of the Q95 of the river and leaving, according to the Environment Agency, a
depleted reach 1.9km long.
Flow-through fish farms additionally pose risks to the migration of fish in rivers.
Juvenile fish, such as downstream migrating salmon and sea trout smolts are at
significant risk from entrainment into fish farm inlets – once in the fish farm ponds or
tanks, their onward migration will be practically impossible and risk of predation from
the farmed fish high. Further, upstream migrating juvenile and adult fish may well
find significant barriers to their migration in the form of weirs and sluice gates on
main channels, designed to direct water into the fish farm. An Environment Agency
Science Report3 eloquently describes the current and ongoing issues with flowthrough fish farms.
These effects of fish farm effluent on water bodies and fish populations will be made
worse by low flows and drought conditions, an important consideration bearing in
mind the current drought and Defra’s recently published Climate Change Risk
Assessment for the Water Sector, which predicts substantial reductions in summer
river flows in many parts of England. In these circumstances, it seems unlikely that
the existing number of flow-through fish farms in England is sustainable.
Flow–through fish farms also pose risks to native fish populations from escapes and
the transmission of diseases and parasites. Escapes have long been a problem with
rainbow trout and signal crayfish were introduced into the wild in England via farm
escapes. The Environment Agency recognises a number of fish parasites with a
significant disease potential that were first identified on fish farms and which have
subsequently spread into the wild e.g. the tapeworm Bothriocephalus acheilognathi.
Examples from neighbouring countries highlight the risks of parasite introduction
from fish farms to wild populations. In Scandinavia, infected hatcheries were
1
Prévost (1999)
Selong and Helfrich (1998)
3 SC030231, Screening for Intake and Outfalls: a best practice guide
2
implicated in the spread to wild salmon of the highly pathogenic parasite,
Gyrodactylus salaris.
Again, climate change may aggravate these risks by creating conditions favourable
to novel diseases and parasites. It could also increase the possibility that novel fish
species, farmed for food or to supply the ornamental fish trade, could survive in the
wild. The ornamental fish trade poses a particular risk, and in our view the current
level of regulation is not adequate. . A recent study4 showed that three species of
exotic sturgeon can now be found in recreational fisheries in England; these same
three species are imported for the pet trade and are now being farmed in a site in
Sussex. Anyone can buy a sturgeon to keep in a garden pond; in Germany this is
only permitted if the fish is microtagged, and when it dies the authorities must be
shown the carcase.
Given the risks to the aquatic environment posed by fish farming in its present form,
both in the sea and in freshwater, we are firmly of the view that any expansion of the
fin-fish aquaculture industry in England will only be sustainable if all new units are
fully contained, with freshwater ones relying on recirculation to minimise water use
and with no outflow to natural watercourses. Those at sea should be designed to
eliminate the dispersal of waste matter, disease and parasites. In particular, no open
cage salmonid units should be authorised in English coastal and off-shore waters. In
the long term, we would like to see all aquaculture units put on this basis, with the
phasing out of flow-through fish farms.
On the question of future research efforts, we would like to see these focused on
developing the technical efficiency and economic viability of closed containment
recirculation aquaculture systems.
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