Protection of Habitat Types: A Case Study of the Effectiveness of a Small Marine Reserve and Impacts of Different Habitats on the Diversity and Abundance of Coral Reef Fishes

摘要

The aim of this work was to compare coral reef fish communities from a small recently established marine reserve (a no-take area, NTA) with 3 nearby fishing areas within Nanwan Bay, southern Taiwan. Two depth zones (shallow at 3-4 m and deep at 8-10 m) of fringing coral reefs were surveyed at each of the 4 study sites. One of the sites was located within a small NTA (1.5 km super(2)) established in 2005 in the western part of Nanwan Bay. Quantitative data on the composition, abundance, and size of fishes and macroinvertebrates were collected by a visual census using 20 x 5 m belt transects (4 transects per depth zone). The coverage of corals, algae, and substratum was estimated using the photoquadrat technique (40 quadrats of 1 m super(2) per depth zone). This will serve as the baseline survey within the marine reserve after it was established. Fish species richness and diversity as well as the abundances of 3 fish families and 2 trophic groups were significantly higher in the NTA than in the 3 other sites in which fishing is allowed. Significant differences in the abundances and sizes of fishes belonging to the Lutjanidae suggest that this family can be used as an indicator to reflect impacts of conservation efforts in the reserve. However, results of multiple regression and correlation analyses suggested that differences in certain reef fish families, especially the Chaetodontidae and Pomacentridae, are attributable to the habitat type and structural complexity of the reefs rather than to conservation efforts alone. This study demonstrates that there is the potential for profound changes toward recovery of fish stocks within small marine reserves over a short time frame.