The importance of benchmarking habitat structure and composition for understanding the extent of fishing impacts in soft sediment ecosystems

Published source details Handley S.J., Willis T.J., Cole R.G., Bradley A., Cairney D.J., Brown S.N. & Carter M.E. (2014) The importance of benchmarking habitat structure and composition for understanding the extent of fishing impacts in soft sediment ecosystems. Journal of Sea Research, 86, 58-68.
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This study is summarised as evidence for the following.

	Action	Category
	Cease or prohibit commercial fishing Action Link

Cease or prohibit commercial fishing

A site comparison study in spring 2008 of 48 sites in a soft seabed area in the Tasman Sea, New Zealand (Handley et al. 2014) found that sites within an area closed to commercial trawling and dredging for 28 years had different invertebrate communities, and higher invertebrate abundance, biomass and productivity than sites subject to intense fishing. Community data were presented as graphical analyses. Sites closed to fishing had greater invertebrate abundance (particularly large and small sizes, but not medium-size), and higher biomass and biological productivity, compared to fished sites (data presented as effect sizes). The larger, rarer individuals contributed the most to the biomass and productivity estimates within the closed sites. Separation Point exclusion zone was legally closed to commercial fishing and shellfish dredging in 1980. In 2008, sediments were collected from the western and southern edges of the exclusion zone, each with 12 samples on each side (24 samples inside and 24 outside the closed area in total) using a grab (0.07 m²) at 20–30 m depth. Invertebrates (>0.5 mm) were extracted, identified and counted. Biomass and productivity were estimated using size-based conversion factors.

(Summarised by: Anaëlle Lemasson & Laura Pettit)