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Providing evidence to improve practice

Individual study: Trade-offs in marine protection: multispecies interactions within a community-led temperate marine reserve

Published source details

Howarth L.M., Dubois P., Gratton P., Judge M., Christie B., Waggitt J.J., Hawkins J.P., Roberts C.M. & Stewart B.D. (2017) Trade-offs in marine protection: multispecies interactions within a community-led temperate marine reserve. ICES Journal of Marine Science, 74, 263-276

This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Designate a Marine Protected Area and prohibit all types of fishing Subtidal Benthic Invertebrate Conservation

A site comparison study in 2012–2015 in eight rocky seabed areas in the Firth of Clyde, west coast of Scotland, UK (Howarth et al. 2017) found that the effects of prohibiting all fishing in a marine reserve on the abundances and sizes of European lobsters Homarus gammarus, brown crabs Cancer pagurus and velvet swimming crabs Necora puber, compared to fished areas, varied between the species. After seven years (in 2015) inside the closed area, there were more European lobsters (1 lobster/pot) and velvet swimming crabs (1.3 crab/pot), compared to fished areas (lobsters: 0.4–0.9/pot; crabs: 0.6–0.7/pot), but fewer brown crabs (closed: 0.8/pot; fished: 1.1–1.3/pot). Over the four-year study, the closed area had on average larger lobsters (closed: 100 vs fished: 82–89 mm) and velvet swimming crabs (71 vs 69 mm) compared to the fished area, but smaller brown crabs (125 vs 147 mm). In addition, over the study period, lobster sex ratios (male:female) were similar across all areas, but the closed area had more females with eggs (8/10 females) than fished areas (1/17). Lamlash Bay marine reserve (2.67 km2) was established in 2008.  In 2012–2015, crustaceans were sampled in summer inside the reserve, in three nearby (<2.5 km away) and four distant (10–20 km away; in 2013–2015 only) fished areas outside the reserve, using baited commercial shellfish pots deployed for 48–72 h (three rows of five pots/area) at 0–10 m depth. Organisms caught in pots were identified and counted. Abundance was derived from catch/unit effort. All lobsters, brown crabs, and velvet crabs were measured (carapace length), sexed, and fecundity recorded.

(Summarised by Anaëlle Lemasson & Laura Pettit)