Summaries of reviewed publications references 86 90.

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

 

Natura 2000 Habitats & Species

Fishing Technique

Effects

Locations

Reference

REF: 86

Shallow inlets and bays

Sandbanks

Scallop dredging

Review of study investigating disturbance by scallop dredging from large (fishing grounds) to small-scale (experimental plots) around the Isle of Man. Dredging disturbs and may be a factor in structuring benthic communities on gravelly sea bed. Community composition is related to the intensity of commercial dredging effort and effects may differ from that of bottom fishing on other soft sediments due to extreme patchiness of animal distribution, greater abundance of epifauna and to the combined effect of the heavy, toothed scallop gear and the stones caught in the dredges.

[Details from abstract only - full paper in press]

Isle of Man

Bradshaw, C. et al., (in press) Effects of scallop dredging on gravelly seabed communities. In:Kaiser, M.J. & de Groot, S.J. (eds). Effects of fishing on non-target species and habitats: biological, conservation and socio-economic issues. Fishing News Books

REF: 86

Shallow inlets and bays

Sandbanks

Scallop dredging

Review of study investigating disturbance by scallop dredging from large (fishing grounds) to small-scale (experimental plots) around the Isle of Man. Dredging disturbs and may be a factor in structuring benthic communities on gravelly sea bed. Community composition is related to the intensity of commercial dredging effort and effects may differ from that of bottom fishing on other soft sediments due to extreme patchiness of animal distribution, greater abundance of epifauna and to the combined effect of the heavy, toothed scallop gear and the stones caught in the dredges.

[Details from abstract only - full paper in press]

Isle of Man

Bradshaw, C. et al., (in press) Effects of scallop dredging on gravelly seabed communities. In:Kaiser, M.J. & de Groot, S.J. (eds). Effects of fishing on non-target species and habitats: biological, conservation and socio-economic issues. Fishing News Books

REF: 88

Shallow inlets and bays

Sandbanks

Scallop dredging

Experimental dredging at two subtidal sandflats (depth around 24m) to identify short-term impacts on macrobenthic communities. Comparison with adjacent reference plots.

Habitat effects Natural surface features broken down (eg.emergent tubes, sediment ripples) and teeth on dredge created grooves 2-3cm deep.

Species and Community effects. Density of common macrofauna decreased at dredged sites and some significant differences still apparent after 3 months. At both sites more than 50% of the common taxa showed significant effects. Differences in recovery process likely to relate to differences in initial community composition and to differences in environmental characteristics. Authors consider the effects recorded were conservative as commercial fishermen work over much larger areas and repeatedly dredge the same area in any one fishing trip.

Mercury Bay, New Zealand

Thrush S.F. et al., (1995) The impact of habitat disturbance by scallop dredging on marine benthic communities; what can be predicted from the results of experiments? Mar.Ecol.Prog.

Ser. 129:141-150.

[PR]

REF: 89

Estuaries

Mudflats and sandflats

Shallow inlets and bays

Aquaculture

Changes in sediment composition and benthic community structure under cultures studied over 3 years in a narrow sound, 13-15m deep with generally weak currents..

Habitat effects. Faecal material and mussels drop to the seabed. As a consequence a layer of sediment was found to increase at a rate of 10cm/yr. This resulted in the production of H2S in the uppermost layers. Small grain size, high organic content and a negative Redox potential recorded under the cultures and changed with distance from the culture.

Species and community effects. Benthic fauna initially dominated by Nucula nitiosa (numerically), Echinocardium cordatum and Ophiura spp (biomass). After 6-15 months these disappeared and were replaced by opportunistic polychaetes (Capitella capitata, Scolelepis fuliginosa and Microphthalmus sczelkowii).

Anaerobic sediments and mass occurrence of opportunistic polychaetes localised 5-20m around the cultures. After harvesting only limited recovery was observed after 6 months.

Sweden

Mattson, J. & Linden, O. (1983) Benthic macrofauna succession under mussels, Mytilus edulis, cultured on hanging long-lines. Sarsia 68:97-102.

[PR]

REF: 90

Sandbanks

Shrimp trawling

Review paper on by-catch associated with shrimp fisheries.

Shrimps tend to live in areas with a great diversity and abundance of other invertebrates and fishes. Many of these caught in trawls. Paper reviews estimates of by-catch, associated mortality of species caught and impacts on ecosystems also discussed. Authors note that there is limited detailed information currently available on this issue.

 

Andrew, N.L. & Pepperell, J.G. (1992) The by-catch of shrimp trawl fisheries. Oceanogr.Mar.Biol.Annu.Rev. 30:527-565. [PR]

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