LE3 .A278 2014

2014

Stokesbury, Michael

Acadia University

Bachelor of Science

Honours

Biology

Biology

As a long-lived and late maturing species, Atlantic sturgeon are susceptible to overharvest, which makes knowledge of their age and growth essential to sustainable management. The Saint John River, New Brunswick, supports one of the two remaining fisheries for Atlantic sturgeon in Canada along with the St. Lawrence River, Quebec, however the relationship between age and growth has not previously been modeled for the Saint John River population. The von Bertalanffy growth model (VBGM) has been used to model the relationship between age and growth for several spawning stocks of Atlantic sturgeon along the Atlantic coast of North America. Pectoral fin spines have been the most commonly used structure for age determination of Atlantic and other sturgeon species due to accuracy and ease of collection. The VBGM of age and length for Atlantic sturgeon in the Saint John River was determined by aging pectoral fin spine sections collected from 233 individuals of known length belonging to that stock. Most of the spine sections (84%) were aged by two of three readers to evaluate possible reader bias. Age-bias plots and coefficient of variation (CV) indicated relatively low precision between readers compared to other studies (readers 1 and 2: CV=6.3%; readers 1 and 3: CV=7.0%). According to VBGM parameters males grow faster than females, but females reach a greater maximum length (males: K=0.05, L∞=247; females: K=0.04, L∞=278). According to the von Bertalanffy parameters for combined sexes, the Saint John River population is medial in terms of growth rate and maximum length to the Hudson and St. Lawrence rivers (K=0.04, L∞=270).

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https://scholar.acadiau.ca/islandora/object/theses:1074