2001–2002 - California Sea Grant - UC San Diego

Innovation Benefiting Sturgeon Aquaculture Industry
12
In recent years, Stolt Sea Farm
California, LLC and other
sturgeon farms stopped the once
widespread practice of replenishing
brood adults with wild-caught
sturgeon. To look at whether the
farm—and the industry as a whole—
might be headed toward a genetic
bottleneck, California Sea Grant
supported a study led by Dr. Bernie
May of the University of California
at Davis.
May and his Sea Grant trainee
examined the genetic diversity of
progeny from the farm’s brood
adults. The research showed, among
other things, that there were large
genetic differences within each of
the four year classes of sturgeon
studied,
meaning
that inbreeding
is
not an
immediate
concern.
A farmed white sturgeon on ice. Photo: Stolt
Sea Farm California, LLC
To prevent inbreeding at white sturgeon farms, Sea Grant researchers, led
by Dr. Bernie May of the University of California at Davis, have mapped
the pedigree structure of a commercial sturgeon brood stock. The geneticists’
work, which was completed in 2001, opens up the possibility of selectively
breeding sturgeon for superior caviar quality, larger size, better feed-conversion
rates and disease resistance.
Such selective breeding strategies would greatly benefit California’s commercial
sturgeon farms, already among the most productive in the nation, by allowing
them to further capitalize on a confluence of international factors now favoring
the expansion of the domestic farmed-caviar industry.
The primary driving force behind this expansion has been the dramatic
collapse of wild sturgeon stocks in the Caspian Sea region—the cradle of the
world’s specialty beluga and osetra caviars. All the region’s sturgeon stocks are
now listed as in danger of extinction. With caviar shortages and efforts to ban the
exportation of some Russian caviars, farmed caviar has emerged as a competitively
priced—and tasty—alternative to wild-caught varieties. Even gourmets,
who compare farmed white sturgeon caviar to osetra, have been won over.
California Sea Grant can take partial credit for establishing the scientific base
on which the rapidly expanding sturgeon industry has been built. Our involvement
began in 1978 when Drs. Wallis Clark and Serge Doroshov of UC Davis were
funded to develop a prototype sturgeon hatchery for white sturgeon. Their
research involved what now seems routine: they collected wild sturgeon
from the San Francisco Bay area, figured out how to transport them in
aerated tanks, then how to acclimatize them to freshwater tanks, and finally
how to induce gamete production. A series of projects led by Doroshov and
others at UC Davis focused on understanding and then manipulating female
sturgeon reproduction. From a commercial standpoint, this work was of
paramount importance for the obvious reason that caviar is roe, and only
females produce it. Consider too that it takes wild white sturgeon 14 to 30
years to reach full sexual maturity, and it becomes readily apparent that
manipulating female reproduction has been key to creating the sturgeon
industry.