Identifier

etd-11042015-124404

Degree

Master of Science in Civil Engineering (MSCE)

Department

Civil and Environmental Engineering

Document Type

Thesis

Abstract

Aquaculture has grown to meet the gap created by a growing demand from population growth and a stagnating wild catch. Recirculating aquaculture system (RAS) is a facet of aquaculture developed to allow the culture of fish in closed systems. The fish are able to survive as the various water parameters are kept within safe ranges by engineered systems and rules of operation. Engineers and operators have attempted to improve the efficiencies of these systems to increase their production. These improvements must guarantee the stability of the system for the entire culture cycle of the fish being raised in an RAS. One strategy that accomplishes this is load leveling. This increases the efficiency of the system by using lightly loaded portions of the system to take the load of portions that are under a heavier load. In crossflow, water is moved from tanks that are heavily stocked with fish to those with a light load of fish. Load leveling is also accomplished by cohort management, in which different fish of different sizes are stocked together. In order to estimate how much the production of a system would increase in these strategies, a computer model was created that modeled a RAS over a series of stocking and harvesting events. The stability of the system was evaluated by the monitoring of water parameters including ammonia, oxygen and carbon dioxide. A baseline study was created and used to evaluate the efficiency of the two load leveling strategies. Each strategy was found to increase the production of the system by upwards of 40% alone and 60% when combined, though this comes at high recirculation rates and high number of stocking groups. A more likely production increase of 30 to 40% is expected when these strategies are used in combination.

Date

2015

Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Malone, Ronald

DOI

10.31390/gradschool_theses.2210

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