Evaluating Summer Flounder Spatial Sex‐Segregation in a Southern New England Estuary

Abstract

Marine fish species can exhibit sex‐specific differences in their biological traits. Not accounting for these characteristics in the stock assessment or management of a species can lead to misunderstanding its population dynamics and result in ineffective regulatory strategies. Summer Flounder Paralichthys dentatus, a flatfish that supports significant commercial and recreational fisheries along the northeastern U.S. shelf, expresses variation in several traits between the sexes, including growth and habitat preference. To further understand these patterns, 1,302 Summer Flounder were collected and sexed in 2016 and 2017 from fisheries‐independent surveys conducted in Rhode Island state waters. Female flounder were more prevalent in shallow waters (≤15 m) through all months, but males had a greater presence in deeper waters (>15 m) from May through September. The probability of a collected flounder being female was evaluated with generalized linear models and covariates representing depth, temperature, month, year, and TL. Summer Flounder were more likely to be female at larger sizes, in shallower waters, and late in the season. When compared with landings data in the recreational fishery over the sampling period, the results suggest that nearly all flounder harvested in the sector were female. This work provides further evidence for and characterization of Summer Flounder sex‐segregation and highlights, for management purposes, the importance of considering fine‐scale spatial dynamics in addition to broader distribution patterns. The fitted model represents an effective first step toward understanding the implications of an aggregated fishing effort for disproportionate removals of male or female flounder and for exploring resulting consequences for regional spawning stock biomass and stock resiliency.

Climate alters the migration phenology of coastal marine species

“…Additionally, lagged values of the RSWT index were correlated to migration phenology in 2 species. In the case of summer flounder, the lagged correlation with ingress timing agrees with a recently proposed link between the effects of slope water dynamics on shelf temperature and juvenile survival (O'Leary et al 2019) and research suggesting young individuals are first to migrate into the coastal zone (Langan et al 2019). While the cause of such patterns cannot be definitively identified from the available data, they do suggest that temperature may also act indirectly on migration through effects on the life cycle.…”

Trophic Level and Proteobacteria Abundance Drive Antibiotic Resistance Levels in Fish from Coastal New England

“…This is particularly interesting given that previous research of summer ounder within Narragansett Bay has found sex-based differences between the two sampling locations. Data suggests that the inshore habitat (Fox Island) has a higher proportion of females during the months our collections took place (May -September), whereas lower in the bay the Whale Rock location has a lower proportion of females [74]. Combined with other work showing that female summer ounder exhibit a faster growth rate [75], and that sex has an effect on microbiome composition in sh[76], future studies could examine whether the changes in summer ounder microbiota observed between the two sites are sex dependent.…”

The Reproductive Biology of Female Atlantic Herring in U.S. Waters: Validating Classification Schemes for Assessing the Importance of Spring and Skipped Spawning

“…; Adams ; differential habitat use by sex, Langan et al. ; or when spawning occurs at specific sites, Lowerre‐Barbieri et al. ).…”