Ecological distribution of Nematopalaemon schmitti and Exhippolysmata oplophoroides (Crustacea: Caridea) near an upwelling area off southeastern Brazil

Upwelling events involves the ascent of cold, nutrient-rich water from subsurface layers to the surface, favoring primary production in the euphotic zone, where mass and energy are transferred through food webs, affecting the marine life where they occur. This study aimed to characterize the influence of environmental factors on the spatiotemporal distribution of the caridean shrimps Nematopalaemon schmitti and Exhippolysmata oplophoroides in an area under influence of Cabo Frio upwelling. Shrimp were collected monthly from July 2010 through June 2011 off Macae on the northern coast of Rio de Janeiro state, Brazil, in six sites located three at a depth of 5 m, and the other three at 15 m. Shrimp abundance was compared among seasons and sampling sites. The influence of environmental factors on the abundances of both species was also tested. We collected 1,200 specimens of N. schmitti , which was more abundant at the 5 m depth; and 2,176 E. oplophoroides, which was more abundant at 15 m. The abundances of the two species differed significantly by season. The abundance of E. oplophoroides and the percentage of organic matter were significantly and positively correlated. The two caridean species had different distributions in time and space, and their migration was correlated with the environmental factors analyzed, particularly the South Atlantic Central Water mass (SACW) boosted by upwelling in the studied region.