%0 Journal Article
%T Fish Larvae Response to Biophysical Changes in the Gulf of California, Mexico (Winter-Summer)
%A Raymundo Avenda£¿o-Ibarra
%A Enrique God¨ªnez-Dom¨ªnguez
%A Gerardo Aceves-Medina
%A Eduardo Gonz¨¢lez-Rodr¨ªguez
%A Armando Trasvi£¿a
%J Journal of Marine Biology
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/176760
%X We analyzed the response of fish larvae assemblages to environmental variables and to physical macro- and mesoscale processes in the Gulf of California, during four oceanographic cruises (winter and summer 2005 and 2007). Physical data of the water column obtained through CTD casts, sea surface temperature, and chlorophyll a satellite imagery were used to detect mesoscale structures. Zooplankton samples were collected with standard Bongo net tows. Fish larvae assemblages responded to latitudinal and coastal-ocean gradients, related to inflow of water to the gulf, and to biological production. The 19¡ãC and 21¡ãC isotherms during winter, and 29¡ãC and 31¡ãC during summer, limited the distribution of fish larvae at the macroscale. Between types of eddy, the cyclonic (January) registered high abundance, species richness, and zooplankton volume compared to the other anticyclonic (March) and cyclonic (September). Thermal fronts (Big Islands) of January and July affected the species distribution establishing strong differences between sides. At the mesoscale, eddy and fronts coincided with the isotherms mentioned previously, playing an important role in emphasizing the differences among species assemblages. The multivariate analysis indicated that larvae abundance was highly correlated with temperature and salinity and with chlorophyll a and zooplankton volume during winter and summer, respectively. 1. Introduction The biological-physical interactions in the oceans play an important role in determining patterns of horizontal distributions of the plankton communities [1], and these interactions occur at a wide range of temporal and spatial scales [2], being the mesoscale processes such as fronts, eddy, and upwelling, the most determinant factors in the spatial distribution and structure of the zooplankton communities on basin and local scales [3]. Mesoscale oceanographic structures such as eddy and fronts can work as mechanisms of retention and concentration of fish larvae [4¨C11], and upwelling filaments, including eddy, may work as mechanisms of dispersion [12¨C17]. The Gulf of California is a semienclosed dynamic sea where strong changes in temperature, salinity, and currents [18] are related to the seasonal flux of the Gulf of California and to tropical surface water masses which provide a unique environment where the southern tropical, subtropical, and northern temperate marine biota develops [19, 20]. The northern region has an anticyclonic circulation most of the year, while in June and September it reverses to a cyclonic eddy [21]. Strong winter upwelling is
%U http://www.hindawi.com/journals/jmb/2013/176760/