Indicators of the Ecological Impact of Bottom-Trawl Disturbance on Seabed Communities |
| |
Authors: | J G Hiddink S Jennings M J Kaiser |
| |
Institution: | (1) School of Ocean Sciences, University of Wales, Bangor, Menai Bridge, Anglesey, LL59 5AB, United Kingdom;(2) Centre for Environment, Fisheries and Aquaculture Science (CEFAS), Lowestoft Laboratory, Pakefield Road, Lowestoft, Suffolk, NR33 OHT, United Kingdom |
| |
Abstract: | The Ecosystem Approach to Fisheries requires that managers take account of the environmental impacts of fishing. We develop
linked state and pressure indicators that show the impact of bottom-trawling on benthic communities. The state indicator measures
the proportion of an area where benthic invertebrate biomass (B) or production (P) is more than 90% of pristine benthic biomass
(B 0.9) or production (P0.9). The pressure indicator measures the proportion of the area where trawling frequency is sufficiently high to prevent reaching
predicted B0.9 or P0.9. Time to recovery to B0.9 and P0.9 after trawling, depending on the habitat, was estimated using a validated size-based model of the benthic community. Based
on trawling intensity in 2003, 53.5% of the southern North Sea was trawled too frequently for biomass to reach B0.9, and 27.1% was trawled too frequently for production to reach P0.9. As a result of bottom-trawling in 2003, in 56% of the southern North Sea benthic biomass was below B0.9, whereas in 27% of the southern North Sea benthic production was below P0.9. Modeled recovery times were comparable to literature estimates (2.5 to more than 6 years). The advantages of using the area
with an ecological impact of trawling as a pressure indicator are that it is conceptually easy to understand, it responds
quickly to changes in management action, it can be implemented at a relevant scale for fisheries management, and the necessary
effort distribution data are centrally collected. One of this approach’s greatest utilities, therefore, will be to communicate
to policy makers and fishing enterprises the expected medium- to long-term ecological benefits that will accrue if the frequency
of trawling in particular parts of fishing grounds is reduced. |
| |
Keywords: | production biomass size-based model fisheries management indicator recovery benthic invertebrates |
本文献已被 SpringerLink 等数据库收录! |
|