Abstract
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 chlorophyllasatellite 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°C and 21°C isotherms during winter, and 29°C and 31°C 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 chlorophyllaand zooplankton volume during winter and summer, respectively.
Highlights
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]
Most of the previous records in this area established that temperature and physical mesoscale processes are responsible for the presence and distribution of fish larvae assemblages at different scales [24, 30, 71], we found that besides T10 and S10, CHL and zooplankton volumes (ZV) gradients used as gross indicators of the biological production and of the amount of available food in the environment were highly correlated with the fish larvae abundance (Table 2) in the Gulf of California, during summer months
The results obtained in this study provide a more comprehensive explanation of the response of the fish larvae community to the environmental complexity of macro, and mesoscale processes in the Gulf of California
Summary
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]. Three to five alternated eddy and jet streams [22, 23] have been registered from south of the Big Islands to the south o the gulf with a markedly seasonal component All these dynamic features may promote a wide diversity of responses of the fish larvae community to the environment
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
