Body size of Atlantic Croaker Micropogonias undulatus in Texas is density dependent

The Atlantic Croaker Micropogonias undulatus is a key estuarine-dependent species in Texas and the greater Gulf of Mexico, particularly as the target for a commercial bait fishery but also as one of the most common bycatch species encountered in commercial shrimp trawls. Declining effort in the inshore (estuarine) shrimp trawl fishery in Texas since the 1990s has resulted in increasing abundance of Atlantic Croaker, although a concurrent change in mean body size has not been explored. Here, the observed abundance of Atlantic Croaker in fishery-independent trawls was related to observed mean total body length in trawls, fishery-independent gill nets, and observed recreational angler harvest from boat ramp intercepts centered on the eight major bay areas of Texas. Annual abundance estimates correlated negatively and significantly with mean size in trawls in 7/8 bays, in gill nets in 4/8 bays, and in angler harvest data in 1/8 bays. Annual growth rate parameters ( k ) for young-of-the-year specimens were developed using size-filtered monthly bag seine and trawl length-frequency data, and the magnitude of k was tightly and negatively correlated with annual abundance coast-wide. Body size of Atlantic Croaker in Texas is driven by annual abundance, and growth of Atlantic Croaker is relatively slow in years when abundance is relatively high. Observed increases in abundance driven by reduced bycatch mortality are driving long-term declines in body size in Texas, which may ultimately drive changes to mean body size in the recreational harvest and commercial bait fisheries.