Stock Evaluation of Three Littoral Echinoid Species on the Catalan Coast North-Western Mediterranean |
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Authors: | Cruz Palacín Xavier Turon Manuel Ballesteros Gonzalo Giribet Salvador López |
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Institution: | Department of Animal Biology Invertebrates. Faculty of Biology, University of Barcelona, 645 Diagonal Ave, E-08028 Barcelona, Spain. E-mail: |
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Abstract: | Abstract. We estimated the abundances of the three common littoral echinoid species Paracentrotus lividus, Arbacia lixula and Sphaerechinus granularis in a littoral zone between 0 and 10m depth on the Catalan shores NE Spain. Densities of each species were estimated from a total number of 11 571× 1 m2 sampling units deployed at 152 sites along the 13 zones into which the coast was divided. The surface area available in each of these zones was estimated at the scale of the sampling unit 1 m2 taking into account the fractal dimension of the shore. The stocks individuals > 2cm test diameter of these species for the whole Catalan shore ? 300 km, straight-line distance were estimated to be about 279.1 × 106 individuals for P. lividus , 28.9 × 106 individuals for A. lixula and 10.9 × 106 individuals for S. granularis. These sea-urchins are key species in the regulation of algal communities and some of them P. lividus. S. granularis are of commercial interest. This information will provide a tool for the future monitoring and management of this resource, which now faces diverse pressures of human origin. |
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Keywords: | Echinoids management stock assessment fractal dimension NW Mediterranean |
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