Executive Summary of Meeting:
This study group is now past the half-way point, and our data collection is largely complete. We have trawl footprint data for over a dozen regions that we used to calculate the proportion of the habitat that is trawled 0, 1, 2 and 3+ times per year. We have access to a global data base on seabed habitats and have begun to download data for our study regions. We have identified 37,000 potential papers that evaluate trawl impacts on biota. Of these, 850 papers whose abstracts and titles suggested they might contain useful data were read thoroughly and 108 of them had data that we were able to use in our analysis. We use these data to estimate the impact of one pass of gear on specific taxa of the benthic biota. Analysis is broken down by taxon, bottom habitat type, and gear type. The literature review also identifies the recovery rate of different taxa in different benthic habitats. The risk analysis that will calculate the cumulative impact of trawl effort on biota is developed and awaits the data inputs from the trawl footprint, benthic habitat, impacts of trawling, and recovery rates. We have largely completed a manuscript reviewing the impacts of trawling on target species and we have identified a broad range of possible best practices and will be evaluating the consequence of implementing these in the next 8 months.
The schematic above was produced as part of Phase IV, and represents the effects of trawling on different components of the ecosystem. Solid arrows are the known links between trawling and components of the ecosystem that could affect fish production. The dotted arrows indicate those effects of trawling for which there is some qualitative support in the published literature.