Biotic and environmental factors affect Southwest Atlantic saltmarsh use by juvenile fishes

VALIÑAS M.; MOLINA, L.; ADDINO, M.; MONTEMAYOR D.; ACHA, M.; IRIBARNE O.

JOURNAL OF SEA RESEARCH

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2012 vol. 68 p. 49 - 56

1385-1101

Fish habitat use is affected by biotic and environmental factors. These factors do not act in isolation; theycommonly operate together, and can be modified by the presence of habitat structure, like vegetation. Westudied at the Bahia Blanca estuary (38° 52′ S, 62 0°6′ W), the seasonal patterns of fish habitat use in aSpartina alterniflora saltmarsh and a contiguous tidal flat, and related them with biotic and environmentalfactors. The results showed that all fish species contributed to differences in the structure of fish assemblagesbetween areas. The silverside Odontesthes argentinensis and the menhaden Brevoortia aurea were moreabundant and smaller in size in the saltmarsh. In this area, the structure of fish assemblage was positively correlatedwith the structure of benthic community. The latter, was probably related to the high abundance ofthe polychaete Laeonereis acuta, the main benthic prey for fishes. Environmental factors that correlatedwith the structure of fish assemblages were particulate organic matter and sediment penetrability, both inthe saltmarsh and in the tidal flat. This evidenced that in terms of physical and chemical factors studied,both areas present similar characteristics for fishes. This work highlights that saltmarshes in southernhemisphere provide both protection and food resources for fishes, and give support to the notion ofsaltmarshes as important fish habitat worldwide.