Growth model of the reared sea urchin Paracentrotus ... - SciViews

General introduction
GENERAL INTRODUCTION
This work was initiated in the context of the global overexploitation of
the natural resources of sea urchin fisheries (Allain, 1972a, 1972b; Le
Gall, 1987, 1990; Ledireac'h, 1987; Conand & Sloan, 1989; Hagen,
1996a). Recently this issue raised considerable interest in sea urchin
aquaculture (echiniculture) (Le Gall, 1990; Cellario & Fenaux, 1990; de
Jong-Westman, 1995a, 1995b; Fernandez, 1996; Hagen, 1996a; Blin,
1997; Kelly et al, 1998; Spirlet et al, 2000, 2001). As a consequence of
their differences [sea urchins are radically different than most marine
species usually farmed (finfishes, molluscs or crustaceans)], specific
rearing methods had to be developed. Our knowledge about the biology of
these animals was too fragmentary and several national or international
programs were established to lead ecophysiological studies of fished
echinoid populations and of the echinoids in culture. In this context, we
worked on two successive European contracts: FAR AQ2.530 BFE "Sea
urchins cultivation" and FAIR CT96-1623 BFN "Biology of sea urchins
under intensive cultivation (closed cycle echiniculture)".
This project presented an opportunity to build an experimental rearing
facility in the Marine Station of Luc-sur-mer, Normandy, France ("Centre
de Recherche et d'Etude Côtière"), where it was possible to grow
thousands of echinoids in strictly controlled food and environmental
conditions. If experiments conducted in this facility shed light on critical
aspects of echiniculture, they are also beneficial to fundamental research
because of the opportunity to experiment at a larger scale than in the
laboratory. This project allowed us to collect exhaustive data on sea urchin
grow when age and genetic origin (artificial fertilizations) are known.
These results revive the "organic growth" (sensu von Bertalanffy, 1938)
models in echinoids.
This introduction is organized in four parts. First, we provide a
summary of the sea urchin fishery, aquaculture potentials, and markets for
Paracentrotus lividus (Lamarck), in the economical context that motivated
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