Master of Science (MS)
Semester of Degree Completion
Robert E. Colombo
Shovelnose sturgeon (Scaphirhynchus platorynchus Rafinesque) are considered one of the last commercially viable options for sturgeon roe harvest. Due to the collapse of several marine sturgeon fisheries and the Similarity of Appearances provision which protect shovelnose sturgeon in only a part of their range, the caviar fishery in the Wabash River remains an important point of supply for this lucrative natural resource. In this thesis, I presented an evaluation of the shovelnose sturgeon commercial caviar fishery in the Wabash River. More specifically, I described the demographic response of this population to continued exploitation over a 10-year period. Additionally, I presented the results of roe yield modeling and recommend new management regulations. This study highlights declines in shovelnose sturgeon population dynamics like size, condition, size and age-at-maturity, and reproductive output of females. Furthermore, I found evidence of a truncated age distribution and greater mortality rates in the population. In the second chapter of this study, I found further evidence of harvest-induced female reproductive dynamics and found that the sturgeon roe fishery is experiencing both growth and recruitment overfishing at the current minimum length limit (635-mm) and estimated levels of exploitation. These findings have highlighted the problems concerning the sustainability of this roe fishery. Changes in management regulations are suggested and future policies should remain conservative to preserve this fishery.
Thornton, Jessica L., "Evaluation and demographic response of the shovelnose sturgeon commercial caviar fishery in the Wabash River" (2018). Masters Theses. 3731.