Spatial patterns of benthic foraminifera as a support to the oceanographic characterisation of Arvoredo biological marine reserve (South Atlantic, Brazil)

• Foraminifera distribution responds to coast-open sea benthic environmental gradient.
• Contaminants from the coast can reach Arvoredo Biological Marine Reserve.
• Areas protected from bottom trawling have low dominance of foraminiferal species.
• Benthic indicators identified the influence of nutrient-enriched waters.
• Results can support discussion about the extent of the reserve's limits.

This paper analyses the distribution of benthic foraminifera in a sector of the inner continental shelf of Santa Catarina State (Brazil), which comprises a Marine Protected Area (MPA). Species indicators of continental input suggest that waters under the influence of continental drainage can eventually reach the southwestern part of the reserve, which might jeopardise the ecosystems of this MPA due to the transport of contaminants related to human activities. Species known to be indicators of high marine benthic productivity were more abundant below 30 m, and were associated with areas under the stronger influence of nutrient-enriched water mass. The high density of foraminifera and the low dominance of species found in most samples inside the reserve might be evidence for the positive effects of the prohibition of bottom trawling, ensuring a higher ecological equilibrium of benthic communities. These results can contribute to the current debate about the reclassification and change in the extent of this MPA.