Project LOBSTAQ : investigations on lobster (Homarus americanus) aquaculture, ecology and tertiary sewage treatment in controlled environmental systems

Research was based on different aspects of incorporating Homarus Americanus cultural into the multi-trophic level marine aquaculture-wastewater treatment system of the Environmental Systems laboratory at Woods Hole. Experiments were directed .toward optimizing food sources available within the system, developing designs to facilitate high density lobster growth, and elucidating the ecology of Homarus. The aquaculture-wastewater treatment system uses secondary sewage effluent or its equivalent as a nutrient source for marine phytoplankton ponds which in turn are fed into raceways containing racks of bivalves. The bivalves produce soluble nutrients used to raise macroalgae, and solid material (biodeposits) used to raise various deposit feeders. Almost all the N and over 50% of the P is removed from the wastewater by the artificial food chain.Prepared under NSF Grant GY-1154

Counterillumination and the upper depth limits of midwater animals

The maximum counterillumination intensities of three species of mesopelagic squids and one species of mesopelagic fish were determined in a shipboard laboratory. The values were compared with the intensity of downwelling irradiance in the ocean measured off Oahu, Hawaii. The upper depth limits of the mesopelagic fauna were determined by mid-day and moonlit-night trawling. The data support the hypothesis that limits on concealment from predation through counterillumination determine the upper depth limits of this fauna during the day. At night near full moon, however, animals may be found at light levels higher than those at which counterillumination seems to be an effective strategy