Details are limited to information relevant to
the UK marine habitats and species listed in the
Habitats Directive and the Birds Directive.
[pr] indicates that the paper is from a peer reviewed
journal or report
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Natura 2000 Habitats &
Species
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Fishing Technique
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Effects
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Locations
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Reference
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REF: 11
Shallow inlets and bays
Sandbanks
(Area of coarse sand, gravel
and broken shell)
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Beam trawling
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Experimental 4m commercial pattern beam trawl
fitted with chain matrix and 8cm diamond mesh
cod-end. Towing speed 2m s-1. Initially
trawl lines fished 3-4x in succession repeated
after 2 hours.
Species and community effects - Gurnards
and whiting aggregate over beam tracks to
feed on animals damaged by the beam trawl
or on other scavengers that are attracted
to the trawled area. There was a particularly
clear increase in the proportion of the amphipod
Ampelisca spinipes in their diets and
some mobile invertebrate scavengers such as
Pandalus spp. only occurred in diets
after the area was fished. Number of prey
items eaten by gurnards and whiting increased
after trawling. Dogfish did not increase their
intake after trawling but did take Pandalus
spp. and Crangon spp. only after the
area had been trawled.
Results suggest that fish rapidly migrate
into the area to feed. Additional resources
such as those made available by trawling,
may favour certain species that exhibit opportunistic
feeding patterns such as gurnards and whiting.
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Off east coast of Anglesey
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Kaiser M.J. & Spenser B.E. (1994). Fish
scavenging behaviour in recently trawled areas.
Marine Ecology Progress Series. 112: 41-49
[PR]
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REF: 12
Reefs
Shallow inlets and bays
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Scallop dredging
Oyster dredging
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Pilot survey of reefs subject to bottom trawling/dredging
on a variety of seabed types; flint shards;
sand, broken shell and dead maerl; sand, gravel,
broken shell and dead maerl overlain with
cobbles and small rocks; reef of mudstone
ledges.
Clear differences in epifaunal communities
between areas considered to be worked by mobile
fishing gear and those not, however different
sediment types in these areas is another influence.
Reefs highly vulnerable to removal of epifauna
and erosion caused by the action of the gear.
Reefs with large boulders or severe topography
which prohibits the use of fishing gear considered
to be self protecting. Complex areas of sandy
pockets, cobbles and boulders the size of
which do not prohibit the use of rock hopper
or spring loaded dredges, which support slow
growing and numerous hydroids, anemones and
corals, bryozoans, tunicates and echinoderms
particularly vulnerable to highly mobile fishing
gear. Recolonisation and recovery likely to
be slow. Potential loss of productivity, habitat,
and food caused by highly mobile fishing gear,
may lead to the direct mortality of commerciality
exploitable reef dwelling species.
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Lyme Bay
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Devon Wildlife Trust (1993). Lyme Bay: A
report on the nature conservation importance
of the inshore reefs and the effects of mobile
fishing gear. Survey report carried out by
the Devon Wildlife Trust.
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REF: 13
Estuaries
Mudflats and sandflats
Inlets and bays
Sandbanks
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Trawling
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Changes in the balance of the benthos, particularly
the loss of Sabellaria reefs and oyster
beds attributed to over-fishing and trawl
damage. Comparable shifts in dominance with
certain polychaete species commonly favoured
over more vulnerable groups such as echinoderms
anticipated at regularly fished sites, and
is, in principal, reversible. Recent trend
towards the deployment of larger, heavier
demersal fishing gear enhances the possibility
of benthic changes in intensively fished areas.
Shrimp fishery in Wadden Sea observed a long
term decline in the number of by-catch species
notably Carcinus and Pomatoschistus
spp. Biomass of by-catch remained constant
with compensating increase in dab, sprat and
cod.
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North Sea
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Rees H.L. and Eleftheriou A. (1989). North
Sea benthos: A review of field investigations
into the biological effects of man’s activities.
J. Cons. Int. Explor. Mer. 54(3): 284-305
[PR]
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REF: 14
Reefs
Shallow inlets and bays
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Potting
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Experimental study on the effects of Nephrops
creels and lobster and crab pots on benthic
habitats and communities in a number of locations/habitats.
Quantitative effects of one month’s fishing
using crab and lobster pots.
Species and community effects - Sites
in Scotland - Descending creels build up a
small pressure wave which caused the sea pens
Pennatula phosphorea, Virgularia mirabilis
and Funiculina quadrangularis to bend
before the creel made contact. This removed
the tip of the sea pen from damage through
impact. After smothering or uprooting all
three species reinserted and uprighted themselves
when in contact with muddy substrate. No lasting
effects on muddy substrates. Devon/Wales -
Rocky substrate habitats and communities at
a depth no deeper than 23m below chart datum
subjected to lobster and crab potting relatively
unaffected by fishing activity. Experimental
and control plots 30mx12m in Devon and 50mx20m
in Wales. Pentapora foliacea found
broken after hauling although unclear whether
this was due to fishing. Eunicella verucosa
bend under the weight of pots and then return
to an upright position afterwards. Slow growing
and long lived Eunicella verucosa previously
considered highly vulnerable to damage. One
month’s active fishing using crab and lobster
pots caused no difference in abundance of
species between control and experimental study
plots. Abundance of some species increased
after potting in comparison with their abundance
before potting. Potting did not have a detrimental
effect on the abundance of species studied.
Experimental simulation of 12 lost parlour
pots revealed that they may actively fish
for up to 270 days and remain baited for between
8 and 27 days. Catch rates highest during
first month. Brown crab catches showed slight
temporary decrease after bait depleted and
subsequently fairly constant. Spider crab
catch declined steadily. In time condition
of the catch deteriorate, wrasse showed skin
damage and limb loss increased markedly the
longer crustaceans remained in the pot. Incidental
observations in the vicinity of the pots shows
several had moved over and broken Pentapora
colonies. Pots moved down the gently sloping
seabed until constrained by mainline tightening.
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Loch Broom, Bardentarbot Bay, Lyme Bay, Skomer,
Pembrokeshire coast.
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Eno N.C., MacDonald D.S. & Amos S.C.
(1996). A study on the effects of fish (crustacea/mollusc)
traps on benthic habitats and species. Report
to the European Commission.
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REF: 15
Estuary
Mudflats and sandflats
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Mechanical cockle dredging
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Experimental investigation on the effects
of cockle dredging on spat settlement using
a 71cm mechanical dredge with revolving riddle.
Species and community effects - A
single pass of the dredge reduced both fishable
and juvenile stocks of cockles substantially.
Adult cockles more damaged by dredge than
juveniles. No subsequent difference in cockle
mortality between dredged and undredged plots.
New spat settlement not affected.
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Burry Inlet
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Walker P. Cotter A.J.R & Bannister R.C.A.
(1995) A preliminary account of the effects
of tractor dredging on cockles in Burry Inlet,
South Wales.
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