UPDATE ON THE 2001 ARTEMIA CYST HARVEST FROM THE
GREAT SALT LAKE (Utah, USA)
From: "Patrick Sorgeloos" <Patrick.Sorgeloos@rug.ac.be>
To: <aqua-l@killick.ifmt.nf.ca>
Date: 3 Apr 2002
Although the 2001 cyst harvest on the Great Salt Lake was a record high in
terms of amount of product (over 9,000 metric tons of wet product, Utah
Division of Wildlife Resources, http://www.wildlife.utah.gov/harvest.html)
several observations reported by the GSL Technical Advisory Group
and the local Artemia companies reveal some particular characteristics,
different from earlier years' harvests.
Whereas in "classical" years, cysts only break diapauze at the end
of the winter, cysts in breaking stage were already observed during the
second half of October, eventually compromising the quality of the end
product.
More surprising was the fact that recently we were able to document that
even after a 3-month cold storage period a significant fraction of the cysts
appear to remain in dormancy at the end of March 2002.
This abnormal behaviour of the cysts does have a negative effect on the
hatching quality of the 2001 cyst harvest as the product is mixed up
with a significant percentage of non-hatching cysts: the ones that are still
dormant + the cysts in early breaking stage (which furthermore will pollute
the hatching medium during cyst incubation).
As a result the major cyst harvesting companies (incl. Western Brine Shrimp
Company, Salt Creek, Utah Strategic Alliance, Ocean Star International)
confirm that quantity wise there is plenty of product in their warehouses,
but from a quality point of view, cysts with a high hatching yield of
80 % and higher will be in very limited supply this year.
We wonder if this "product" difference needs to be related to the
abnormal ecological conditions of the lake (record low salinity), or to
changing population characteristics.
Using the 2001 cysts we are in the process of studying the life history
characteristics in comparison to earlier GSL harvests
Prof. Dr. Patrick Sorgeloos
Laboratory of Aquaculture & Artemia Reference Center, Ghent University
Rozier 44, B-9000 Gent, Belgium
tel +32-9-2643754; fax +32-9-2644193
e-mail (internet) patrick.sorgeloos@rug.ac.be
www homepage: http://www.rug.ac.be/aquaculture
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