Experimental Aquarium at the Southwest Fisheries Science Center
The aquarium at the Southwest Fisheries Science Center facilitates research across many species, including the endangered black and white abalone.
The Southwest Fisheries Science Center aquarium is an established, 4,500 ft2, 300 - 380 LPM (liters per minute) seawater flow-through facility located in La Jolla, California. Unfiltered seawater is pumped from the Scripps Institution of Oceanography pier and passes through a series of sand filters before it arrives at the Southwest Fisheries Science Center.
When the water arrives at the Southwest Fisheries Science Center, the water immediately runs through a large degassing tower, which uses a venturi to inject air into the water. The venturi creates bubbles that help remove proteins and amino acids from the water by carrying them to the surface while water is pumped from the lower section of the water column to the aquarium filtration systems. The water is then passed through twin #6-20 silica sand filters that remove suspended solids down to 30 microns. Next, the water passes through an ozone system. Ozone is the triatomic form of oxygen in which air is energized and injected into the seawater. Ozone is unstable and as it breaks down, the free oxygen molecule oxidizes inorganic and organic matter, including bacteria and viruses.
Following the ozone system, the water is further cleansed through UV sterilizers, the UV light denatures the DNA of potential bacteria, viruses, and other microorganisms. The ozone and UV sterilization processes both can have negative effects on the health or behavior of species in the aquarium, so prior to entering the aquarium the water is run through activated carbon filters to remove excess radicals. The water is then diverted to an ambient line and two heat exchangers that supply the lab with heated seawater, chilled seawater, in addition to ambient seawater. It is then delivered to the aquarium facility and distributed amongst 12 sets of temperature mixing stations.
The mixing stations are associated with a set of tanks of varying system volumes and sizes (24 tanks from 200 to 11,000 liters volume). Temperature is controlled at each mixing station by a centralized computer and remotely monitored by two redundant systems. Temperatures can be manipulated in each of the mixing stations at ranges from 5 to 30 °C. The final step before the water makes contact with the animals is a degassing unit. The ozone process creates oxygen as a byproduct, so the water must be agitated over media to “degas” and offset the supersaturation.
In 2015, a 170 LPM Recirculating Aquaculture System and 20 tanks (180 – 1500 liters volume) were installed to increase research capacity. All water pumped through this system is recaptured in a sump with a 10% addition of fresh makeup water, relieving pressure on the aquarium main seawater systems. This mounted skid contains independent bead filtration in which mechanical and biological filtration takes place. The biological filtration is completed as the bead media is coated with a film of heterotrophic and nitrifying bacteria that co-exist in the filter and remove dissolved organics and convert toxic ammonia and nitrite to nitrate, respectively. The system also contains a UV sterilizing unit, 50-micron bubba filtration, a heat pump/chiller and degassing unit to prepare water for return to tanks.
The aquarium facility supports many aspects of fisheries and aquaculture research across various departments and disciplines at the Southwest Fisheries Science Center (FRD, CPS, HMS, abalone, etc.). The species currently under culture for research include, but are not limited to several species of rockfish; Pacific Sardine, Pacific Mackerel, Northern Anchovy, California Yellowtail; and five species of abalone, including the endangered white and black abalone.