Date of Award

2025

Degree Type

Thesis

Degree Name

Master of Science in Biological and Environmental Sciences (MSBES)

Department

Fisheries, Animal and Veterinary Science

First Advisor

Coleen Suckling

Abstract

Biofouling on shellfish and aquaculture gear is a persistent problem for the oyster aquaculture industry, requiring significant resources to clean and prevent. Previous studies have investigated naturally controlling biofouling by using grazing sea urchins integrated with shellfish with successful results. In Rhode Island (USA), the native unexploited purple sea urchin (Arbacia punctulata) has yet to be tested for biofouling control and co-culture with shellfish. The aim of this study was to determine whether the commercially unexploited native purple sea urchin A. punctulata can be integrated with eastern oysters, (Crassostrea virginica), in Rhode Island using an oyster farm as a case study. It is hypothesized that gear and oyster shell biofouling will be reduced and that oyster growth will increase when integrated with A. punctulata. This study examined integrating A. punctulata at different densities (0, 1, and 3 urchins per bag) with oysters (n=25 per bag) for 2 months (Sept.-Nov. 2023) and measured biofouling levels on gear and shell surfaces, and organismal survival, growth, and quality relative to the market. Results showed that when A. punctulata reduced gear biofouling by 50% to 90% and 60% to 90% from shellfish surfaces for low (1 urchin per bag) and medium (3 urchins per bag) urchin stocking densities respectively, without compromising the growth or survival of oysters. The inclusion of 3 sea urchins per bag, fully prevented the shell burrowing worm, Polydora sp and produced oysters at a similar market standard of cleanliness as the farm baselines. These results demonstrate strong potential for the sea urchin species A. punctulata to be used as a biofouling control agent and support the growing demand for future trials at production level.

Available for download on Saturday, January 23, 2027

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