Diversity of copepods in South West Atlantic Patagonian coastal waters throughout an annual cycle

MARIELA L. SPINELLI; RODRIGO GONÇALVES; VIRGINIA E. VILLAFAÑE; FABIANA L. CAPITANIO

CIENCIAS MARINAS

INST INVESTIGACIONES OCEANOLOGICAS, U A B C, APARTADO POSTAL 423

Lugar: Ciudad de México; Año: 2016 vol. 42 p. 31 - 47

0185-3880

The aim of this study is to analyze the zooplankton annual succession in a coastal station of Patagonia (Argentina) - with special emphasis on copepods and their potential preys, with solar radiation and temperature as environmental factors. Plankton annual cycle exhibited autumn-winter and spring-summer phases. During the autumn-winter phase, low temperature and radiation were correlated to higher diatom abundance and copepod diversity. This period was characterized by a dominant classical herbivore food web in which the large copepod Calanoides carinatus dominated the community. On the contrary, during the spring-summer period, with high radiation and temperature levels, flagellates dominated as food available for zooplankton which was correlated to smaller species of copepods such as the harpacticoid Euterpina acutifrons. Also, intensive reproduction of the small copepods, E. acutifrons and P. parvus took place mainly in summer. On the other hand, high diversity of species was found in winter when the UVR was low. The temporal pattern of the copepods observed in our study was explained by the food availability and the environmental factors (temperature and solar radiation), although other factors such as the predator abundance may be also important in modulating the community. Our results show the importance of copepods abundance dynamics and highlights its key role in the pelagic-food web in North Patagonian coastal waters.