Aquaculture America 2020

February 9 - 12, 2020

Honolulu, Hawaii

EFFLUENT BIOREMEDIATION BY THE POLYCHAETE WORM Alitta brandti IN A MARINE RECIRCULATING SYSTEM

Michelle Loftus, Rafael Cuevas-Uribe
 
Department of Fisheries Biology
Humboldt State University
Arcata, CA 95521
mll19@humboldt.edu
 

Marine aquaculture plays an important role in providing seafood for the world.  One of the biggest challenges in marine recirculating aquaculture systems is the handling of wastewater. Finding organisms that have the potential to feed on these organic wastes such as  sea cucumbers could be beneficial for waste bioremedi ation.  One limitation for using this effluent is the low concentration of protein (2.3%) and fat (0.5%) with notably low omega-3 fatty acids (EPA 1.9, DHA 0.9, and linolenic 0.8 W/W% grams per 100 grams of wet effluent) . The goal of this project is to provide compelling evidence that the California Sea Cucumber, Parastichopus californicus , can assimilate and growth by feeding enriched effluent from a Sablefish, Anoplopoma fimbria recirculating system.

A 25-day feeding trial was being conducted in a recirculating aquaculture system where individual polychaete worms were fed  effluent with  different concentrations of  soybean meal. The treatment diets includde: a)72% soybean meal + 20% effluent (control) , b) 46% soybean meal + 46 % effluent, c) 20% soybean meal + 72% effluent ,  and d) 10% soybean meal + 82% effluent. The diets with soybean meal were enriched with 2% of the microalgae Schizochytrium sp. and  6%  canola oil to supplement the fatty acids, especially the omega-3.  Ammonia, nitrite,  nitrate, temperature, and alkalinity are measured once per week.This is an on-going project, and the results from this study will be presented at the conference.