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

to as roe) as either a fine and delicate seafood or as absolutely inedible.
However, its economic value is well established given the price consumers
are willing to pay. The wholesale price of live sea urchins in France ranges
from 30 to 120 FF/kg (price range in the 1990s at Rungis, Paris), and fresh
roe in Japan from 6,000 to 14,000 ¥/kg (price in Japan in the 1990s, see
Hagen 1996a). Both market prices are roughly equivalent in terms of fresh
roe, making sea urchin roe one of the most valuable seafoods in the world.
In both markets, the lowest prices are those of imported sea urchins, which
are considered to be of poorer quality.
The most important market, Japan, imports approximately five
thousand tons of sea urchin gonads per year, the equivalent of 40 to 50
thousand tons of live sea urchins (Hagen, 1996a). According to the same
author, the Japanese consumes approximately 60,000 tons of whole sea
urchins per year. The second largest consumer is France, with an annual
consumption of approximately 1,000 tons of whole sea urchins (Le Gall,
1990).
Increasing demand for sea urchin roe and a steady rise in price have led
to worldwide intensification of sea urchin fisheries (Conand and Sloan,
1989; Le Gall, 1990; Saito, 1992) which has now (1998) probably reached
its maximum. This production cannot be sustained at current levels
because the declining productivity of overexploited existing stocks can no
longer be compensated by harvest of new stocks, as was possible over the
last three decades (most exploitable natural populations have already been
fished today). In Japan, this decline occurred despite the development and
implementation of extensive domestic fishery enhancement techniques
which include the annual release of 60 million juvenile sea urchins into the
wild (Saito, 1992; Hagen, 1996a). Consequently, the worldwide supply of
high quality sea urchin roe will be unable to meet market demand unless
commercial sea urchin aquaculture develops to partially replace the steady
decrease in natural captures.
Part I: Set up of an experimental rearing procedure for echinoids
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