Diversity, secondary production and fishing disturbance relationships in the Río de la Plata (34°-36°S), a large estuary (35.000 km2) of the Southwestern Atlantic

GIBERTO, D.A.; BREMEC, C.S.

Aberdeen, Escocia

Congreso; World Conference of Marine Biodiversity 2011; 2011

Many hypotheses stated that diversity should peak at intermediate levels of disturbance and productivity, but multiple responses have been found in distinct ecological systems. We analyzed the relationship between benthic richness, annual production and bottom-trawl fisheries in RLP. A database with its corresponding richness data, fishing intensity (km2.year) and production estimates (total production) was used (78 sites, 1999-2005, Inner-Middle-Outer RLP). Differences between areas for richness (ANOVA, F=6.55, p=0.02), total production (ANOVA, F=6.55, p=0.02) and trawl intensity (ANOVA, F=4.62, p=0.013) were found. Middle (average ± SD= 217.14±349.9 KJ.m2.y) and Outer (106.03±105.9 KJ.m2.y) areas showed the highest production, while highest richness (10.7±7.7 ind.m2) and trawling (2.16±3.6 km2.y) was found in Outer area. The richness (ANOVA, F=1.08, p=0.30) and production (ANOVA, F=0.39, p=0.54) in trawled and non-trawled sites was similar. A significant relationship was found between richness and production (simple linear regression, R2=0.51, p