First implementation of the Large Fish Index (LFI) in the eastern Mediterranean
Dor Edelist, Daniel Golani, Ehud Spanier

The composition and structure of fish assemblages caught by trawl in the Levantine Sea (eastern Mediterranean) were summarized using a fishing-sensitive univariate indicator. This metric, called the ‘Large Fish Index’ (LFI), has been developed in the North Sea since 2000 and is applied and adapted here for the first time in the eastern Mediterranean. It was defined as the fish biomass fraction above a pre-determined length threshold, expressed as proportion of the total fish biomass. Trawl-caught assemblages in the warm, oligotrophic, highly invaded Levant were found to be characterized by small fishes. ‘Large fish’ were thus delineated as 20-30 cm (total length) for this region, as opposed to 40 cm set in the North Sea. Desired minimum LFI proportions were set as 0.5 for fishes longer than 20 cm and 0.3 for fishes longer than 30 cm and the actual values found in Israeli bottom trawl surveys from 2008 to 2012 were 0.3 and 0.155 respectively. These low LFI values for the small fishes caught by trawlers attest to the ecological unsustainability and economic inefficiency of bottom trawling in Israel and provide a tool for managers with which to assess the state of the fishery and the general health of the ecosystem.

Keywords: fish; overfishing; indicator; trawl; Mediterranean; Large Fish Index
Contents of this volume Sci. Mar. 78(2) : 185-192 Back PDF
 
 
Please, send comments to
ICM (CSIC) - Passeig Marítim de la Barceloneta, 37-49. E-08003 Barcelona (Spain)