Aquaculture 2022

February 28 - March 4, 2022

San Diego, California

THE EVOLUTION OF PRODUCTION PRACTICES AT A HIGH PROFILE CONSERVATION HATCHERY FOR WHITE SEABASS IN SOUTHERN CALIFORNIA

Lauren Mazzola*, Michael Shane, Alex Primus and Mark Drawbridge.

 

Hubbs-SeaWorld Research Institute

2595 Ingraham St, San Diego, CA 92109

lmazzola@hswri.org

 



Hubbs-SeaWorld Research Institute (HSWRI) has operated a dedicated marine finfish hatchery in Carlsbad, California since 1995 and it remains the only such facility on the west coast of the contiguous United States to this day.  The primary mission of this facility and its team of dedicated staff has been to support regional conservation efforts for depleted marine fishes, with a focus on white seabass Atractoscion nobilis.

During this multi-decadal period, production and general operating practices have expectedly evolved and undoubtedly will continue to do so.  The evolution has occurred primarily with advances in science and technology, but also with changing environmental conditions.  Among the biggest changes during this period has been the shift from mostly flow through systems to recirculating aquaculture systems (RAS) for early life stages in order to maximize environmental control and biosecurity.  The use of RAS has also evolved as various components and combinations of components have been tested to their limits in a saltwater environment.  An improved understanding of group spawning dynamics has moved production plans towards more batches of smaller numbers of fish than the hatchery was originally designed for – a source of inefficiency that is currently being addressed.  A sophisticated quality assessment and control program has been developed over time as emphasis has shifted from quantity to quality after achieving survival rates consistently greater than 20% (as high as 60%) from egg to fingerling.  A clear demonstration that acclimation cages improve post-release survival by two-fold has eliminated releases directly from the hatchery and shifted practices to a minimum two-week cage acclimation period.  Warming water conditions have shifted the prime 6-7 month growout season to fall and spring months.  Previously, winter would be avoided for small seabass that were not otherwise physiologically adapted for cold water conditions.  Now the summer is avoided to help avoid gas bubble disease, which is exacerbated in warm, shallow water.  Growing fish to a larger size has also been demonstrated successful and this is driving the need for larger acclimation cages that require more resources to effectively operate; especially in relation to managing biofouling.

There are exciting opportunities for continued evolution of the Program, including applying our knowledge to new species like California halibut.  The biggest challenge to the extent and pace of this evolution is the funding required to implement.  Perhaps the greatest opportunity in this evolution is to adapt what has been learned and apply it to traditional farming as another means to take pressure off wild fisheries.  The biggest challenge thwarting this opportunity is regulatory and not technical.