Conservation Evidence strives to be as useful to conservationists as possible. Please take our survey to help the team improve our resource.

Providing evidence to improve practice

Individual study: Effects of anti-trawling artificial reefs on ecological indicators of inner shelf fish and invertebrate communities in the Cantabrian Sea (southern Bay of Biscay)

Published source details

Serrano A., Rodríguez-Cabello C., Sánchez F., Velasco F., Olaso I. & Punzón A. (2011) Effects of anti-trawling artificial reefs on ecological indicators of inner shelf fish and invertebrate communities in the Cantabrian Sea (southern Bay of Biscay). Journal of the Marine Biological Association of the United Kingdom, 91, 623-633


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

Install physical barriers to prevent trawling Subtidal Benthic Invertebrate Conservation

A before-and-after study in 1998–2007 in one area of soft seabed in the Cantabrian Sea, southern Bay of Biscay, Spain (Serrano et al. 2011) found that one to four years after installing barriers to prevent illegal trawling the biomass of invertebrates increased, and species community composition changed. Total invertebrate biomass was higher after one (3 kg/ha) and four years (7 kg/ha), compared to before installation (0–1 kg/ha). There were increases in the biomass of sea urchins (before: 12; after: 3,150 g/ha), common octopus Octopus vulgaris (before: 222; after: 920 g/ha), starfish (before: 9; after: 78 g/ha), gastropods (before: 18; after: 50 g/ha), cuttlefish Sepia spp. (before: 56; after: 131 g/ha), and curled octopus Eledone cirrhosa (before: 9; after: 18 g/ha). Invertebrate community composition was different before and after deployment (results presented as graphical analyses). Bottom trawling in the area was prohibited at depths <100 m by local legislation, but illegal trawling was common. To prevent it, artificial reefs (groups of concrete blocks 2 km apart; numbers not specified) were deployed in 2003 at 80–85 m depth. One sampling station near each group of blocks (sandy seabed without blocks) was surveyed annually in October in 1998–2007 (survey methods not specified).

(Summarised by Anaëlle Lemasson)