Climate-related meteorological and hydrological regimes and their influence on recruitment of Gulf menhaden (Brevoortia patronus) in the northern Gulf of Mexico

The views and opinions expressed or implied in this article are those of the author (or authors) and do not necessarily reflect the position of the National Marine Fisheries Service, NOAA. Abstract—Abundances of Gulf menhaden (Brevoortia patronus) in the northern Gulf of Mexico (GOM) are heavily influenced by physical and biological processes that affect refuge and food availability. This study identified specific decadal and interannual responses in the recruitment of Gulf menhaden to local meteorological and hydrological regimes imposed by the coupling of Atlantic Multidecadal Oscillation (AMO) and North Atlantic Oscillation (NAO) phases and by El Niño Southern Oscillation (ENSO) events. Numbers of age-0 menhaden in fishery-independent surveys and numbers and proportions of Gulf menhaden ages 1–6 in commercial purse-seine landings in the northern GOM were used to investigate those responses. High postlarval abundance of Gulf menhaden (3.6/beam plankton haul) in the central region was related to the decadal wet regime associated with AMO cold and NAO positive phases. Elevated numbers of menhaden species (38.3/seine haul) in the western region were related to interannual wet regimes associated with ENSO warm and neutral events. High commercial landings of Gulf menhaden (10 million fish/vessel ton week) were related to the decadal average hydrological regime associated with AMO cold and NAO negative phases. Climate regimes may favor growth and survival by structuring offshore and inshore nursery habitats or by synchronizing release of larvae when offshore and inshore nursery conditions are favorable. Gulf menhaden (Brevoortia patronus) spawn in offshore marine waters and juvenile development occurs in nearshore nursery areas. Spawning occurs in the late fall and winter, peaking between December and February (Gunter, 1945; Guillory and Roussel, 1981; Shaw et al., 1985; Christmas et al.1). On the basis of the distribution of eggs, Fore (1970) noted that spawning occurred mainly over the continental shelf in the northcentral Gulf of Mexico (GOM) and that the greatest concentrations were found in waters between 8 and 70 m off Texas and Louisiana and near the Mississippi River Delta. Christmas and Waller (1973) and Sogard et al. (1987) also found high densities of larvae near the Mississippi River. Late-stage larvae recruit to estuaries during the winter and spring, and there they transform into juveniles and remain for several months before moving back to open Gulf waters (Suttkus, 1956; Christmas and