Population trends of Banggai cardinalfish in the Banggai Islands, Central Sulawesi, Indonesia

Abstract

The Banggai cardinalfish (BCF) (Pterapogon kauderni) is endemic to the Banggai Archipelago, Indonesia and has received international attention due to the decline in its population. As the sole range state, Indonesia has a responsibility to conserve the BCF through initiatives for its sustainable management. To inform management and evaluate management effectiveness, a research program has been set up to monitor BCF populations at 24 sites. The initial (T0) baseline survey in 2017 was followed by the first annual monitoring (T1) in 2018. At each site, data collected in 6 belt transects (20 x 5m) comprised BCF density by size class, and microhabitat density (sea urchins and sea anemones). The Students t-test was applied to test for significant differences in BCF population density between T0 and T1 results, and correlation with influencing factors was evaluated using multiple regression (α = 0.05). The overall adult population trend was positive, despite declines in BCF density at some sites. BCF density was positively correlated with both sea urchin and sea anemone densities; however, the correlation with sea anemone density was stronger. These results reinforce the importance of protecting sea anemone and sea urchin microhabitat, as part of a holistic approach to rehabilitating and sustaining BCF stocks.