Spatial and Temporal Patterns of Black Sea Bass Sizes and Catches in the Southeastern United States Inferred from Spatially Explicit Nonlinear Models

Nathan M Bacheler,Joseph C Ballenger

doi:10.1080/19425120.2015.1095826

Abstract

AbstractTemporal and spatial variability in abundance often results from the effects of environmental and landscape variables interacting over multiple spatial scales, and understanding the complex interplay among these variables is key to elucidating the drivers of a species' population dynamics. We used a spatially explicit, variable‐coefficient, generalized additive modeling approach with 24 years of fishery‐independent trap data (N = 11,726 samples) to elucidate the spatiotemporal dynamics of size and size‐specific CPUE of Black Sea Bass Centropristis striata along the southeastern Atlantic coast of the United States. Black Sea Bass catch exhibited complex spatial and temporal dynamics that were influenced by environmental, landscape, and sampling effects. Black Sea Bass were more commonly caught inshore than offshore, but were significantly smaller inshore and southward and larger offshore and northward in the study area. Moreover, the spatial distribution of Black Sea Bass changed as abundance varied within and among sampling seasons. Standardized mean length of Black Sea Bass also increased by more than 20% over the study period, from 230 mm TL in the early 1990s to 280 mm TL after 2010. These results elucidate the spatial and temporal dynamics of Black Sea Bass, inform population structure and indices of abundance, and provide an analytical framework that can be easily adapted to other species and systems.Received October 31, 2014; accepted September 14, 2015

Highlights

Recent analytical advances have helped us understand the complex interplay between environmental and landscape influences on the spatial dynamics of organisms (Lehmann et al 2002; Bacheler et al 2009)
Standardized mean length of Black Sea Bass increased by more than 20% over the study period, from 230 mm TL in the early 1990s to 280 mm TL after 2010. These results elucidate the spatial and temporal dynamics of Black Sea Bass, inform population structure and indices of abundance, and provide an analytical framework that can be adapted to other species and systems
We found complex spatial and temporal dynamics of Black Sea Bass that were influenced by environmental, landscape, and sampling effects over the 24 years of the survey

Summary

Introduction

Recent analytical advances have helped us understand the complex interplay between environmental and landscape influences on the spatial dynamics of organisms (Lehmann et al 2002; Bacheler et al 2009). Bacheler et al (2012) used a similar modeling approach to document densitydependent estuarine habitat use of Red Drum Sciaenops ocellatus after removing variability in catches due to various environmental and landscape effects Another fish species for which spatially explicit modeling would be useful to explicate temporal and spatial dynamics is the Black Sea Bass Centropristis striata, a protogynous serranid that occurs in nearshore waters of the U.S Atlantic Ocean and Gulf of Mexico (Lavenda 1949; Wenner et al 1986; Hood et al 1994). We intended to provide an analytical framework that can be adapted to other species and systems

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Conclusion