Angel, D. L. Israel Oceanographic and Limnological Research Inst., angel@agri.huji.ac.il
Post, A. L. Hebrew University of Jerusalem,
Brenner, S. Israel Oceanographic and Limnological Research Inst.,

 
DISSOLVED EFFLUENTS RELEASED FROM MARICULTURE IN THE RED SEA ARE EPHEMERAL, POSSIBLY DUE TO ASSOCIATED BIOTA
 
Marine fish farms release large quantities of dissolved and particulate compounds to the surrounding waters during the fish rearing process. For example, a fish farm producing 1000 tons of seabream would release approximately 115 tons of dissolved nitrogen to the marine environment. In the oligotrophic Gulf of Aqaba we expected to find an increase in dissolved organic matter and nutrient levels in the waters surrounding the fish cages (relative to control stations), despite chemical transformations and biological incorporation of the released material, but this was not the case. Increase in planktonic chlorophyll a levels, above background, in the proximity of the fish farm was as high as 4-fold, but this cannot account for all of the N and P released. Although this aspect has largely been ignored in the past, we propose that the biological community associated with the fish farm plays a fundamental role in absorbing a large part of the dissolved and particulate material that is released, and this is at least partially why the dissolved effluents are ephemeral. The practical implications of the dynamic biofouling and free-living biota associated with the fish farm will be discussed.
 
Day: Monday, Feb. 1
Time: 03:45 - 04:00pm
Location: Hilton of Santa Fe
 
Code: SS06MO0345H