Commercial harvest and population characteristics of freshwater drum and buffalo Ictiobus spp. in Ohio waters of Lake Erie

Abstract

Lake Erie supports many native nongame fishes including freshwater drum, bigmouth buffalo, and smallmouth buffalo. Commercial fisheries in Ohio waters of Lake Erie have no specific regulations on these species. We reviewed the commercial harvest records for these species and quantified population characteristics (size structure, age and growth, length and age at maturity, recruitment variability, and mortality rates) with fishery-independent samples. Commercial harvest effort has generally declined through time, but commercial harvest totals have increased, suggesting potential increases in population size. Sexually dimorphic growth occurred for each species, with females attaining larger sizes than males. Total annual mortality was 6.7–12.2% and recruitment variability indexes ranged from 0.44 to 0.51. Most fish of all species matured by age 6 or 7, and maximum observed ages were 56 years for freshwater drum and 48 years for buffalo species. A catch-only surplus production model suggested overharvest of freshwater drum, and buffalo species has occurred in the past and is likely ongoing. However, these results disagree with biological information collected on the fishery (i.e., age structure, growth, and recruitment). We suggest it is likely some level of overharvest is currently occurring in this fishery; however, more detailed assessment of harvest (i.e., information about size structure rather than aggregate total biomass removed) should be conducted to ensure it can be sustainably managed.