Setting preliminary biometric baselines for new target sea cucumbers species of the NE Atlantic and Mediterranean fisheries

Commercial interest on sea cucumber species from the NE Atlantic and the Mediterranean is increasing.Holothuria polii, Holothuria tubulosa, Holothuria mammata and Holothuria arguinensis are the new targetspecies. The scarce biological and ecological knowledge on these species along their geographical distri-bution, is a major problem for their fisheries management. To address it, we carried out a morphometricstudy to describe the baseline population size structure, focused on the length–weight relationship andsize–weight distribution.In the NE Atlantic, the largest mean size and heaviest mean weight of H. mammata and H. arguinensiswere found in localities with upwelling, but another factors could be influencing on these results. In theMediterranean, Girona and Mallorca showed the heaviest specimens of H. polii, H. tubulosa and H. mam-mata, and the smallest were registered in Crete and Kusadasi. Significant differences in length and weightbetween populations were found for each species. These results could be linked with local environmentalconditions. Size frequency distribution was multimodal for all species except for H. mammata; the weightfrequency distribution was only unimodal for H. polii and H. mammata.This study provides novel data, helpful for stock and population assessment which could support theimplementation of effective management for the European sea cucumber target species.