Improving the characterization of fish assemblage structure through the use of multiple sampling methods: a case...

Area of Science:

• Marine Biology
• Ecology
• Fisheries Science

Background:

• Species-rich subtropical ecosystems necessitate diverse sampling methods for accurate fish assemblage assessment.
• Tidal flat ecosystems are crucial habitats for various fish species, including threatened ones.

Purpose of the Study:

• To characterize the high-tide fish assemblage structure and estimate species richness in Araçá Bay, Brazil.
• To demonstrate the indispensable role of multiple sampling gears in subtropical fish research.
• To provide baseline data for monitoring biodiversity impacts from imminent port expansion.

Main Methods:

• Utilized eight different sampling gears across five seasonal surveys.
• Combined data with local tide pool fish surveys to estimate species richness.
• Analyzed spatial structure, species composition, and seasonal variability of the fish assemblage.

Main Results:

• The high-tide fish assemblage was spatially structured and included five threatened species.
• Dominant species included Eucinostomus argenteus, Mugil curema, and Diapterus rhombeus, indicating intensive bay use.
• Seasonal variability was driven by autumn-winter peaks in juvenile fish abundance and subsequent piscivore activity.
• Estimated fish richness suggested high biodiversity in Araçá Bay compared to regional coastal ecosystems.

Conclusions:

• Multiple sampling gears are essential for comprehensive fish biodiversity assessment in subtropical tidal flats.
• Araçá Bay supports a diverse fish assemblage, including vulnerable species, vital for regional biodiversity.
• The study provides critical data for future monitoring of port expansion impacts on local fish populations.