Resumen del producto

River plume fronts are hydrographic structures that besides functioning as effective physical barriers to contain dispersion towards the oceanic zone, and delay river run-offs dispersion, stands out as highly productive systems. These structures concentrates large amounts of planktonic organisms, including high richness of fish larvae, facts that contributes to consider them important nursery sites for fishes. In the Mexican Central Pacific coast off Nayarit, there is a lack of knowledge about the role of fronts in the early life stages of fish. The aim of this study is to determine the community structure fish larvae in relation to environmental conditions around the Santiago's river plume front, and compare it to those from Isabel Island, Coral Island and Marietas Islands, in Nayarit's coast during 2017 late dry season. Hydrographic and biological data were obtained during PROFRENTES-02 oceanographic campaign and sampling in the Islands during June 2017. The physical parameters were obtained through CTD casts, and zooplankton samples through surface tows (500 µm mesh 50 cm diameter conical nets). Fish larvae were separated and standardized to 10m², spatial distribution maps of the physical and biological variables of the study area were constructed to analyze its spatial distribution. Three different environments were identified on Santiago's river plume front area (mainly based on salinity, turbidity and stratification). The highest zooplankton concentration was recorded near the mouth of the river at night. A total of 78 fish larvae taxa that belonged to 28 families were registered, of which 10 are of fishing interest. The fish larvae abundance were similar in all stations during the day and showed low values (1-7 larvae 10m²). During the night, larvae abundance on the front was higher (16-47 larvae 10m²) in comparison to stations located near river mouth (8-15 larvae 10m²). The islands zones had the lowest larvae abundance (1 larvae 10m²). Four fish larvae assemblages were distributed in the study area, one distributed in the Islands, one off the front, one on the front, and the last inside the river plume. The physical and biological data showed high spatial variability, the spatial distribution of the associations was related to the marine environments, and despite the small spatial scale the river plume front of Santiago river constitutes an important site for fish larvae development, fishing interest species.

Palabras clave: Nayarit; Santiago river; plume of river; front; islands

Para obtener una copia del documento contacta la personal de la biblioteca a través del correo bibliocicimar{a}ipn.mx