Size and species diversity of fish utilising a created mangrove

Among estuarine habitats, mangroves are widely considered valuable to both fish and human beings due to their ecosystem services, e.g. acting as nursery site to juvenile fish. Accordingly, much resource has been invested in... [ view full abstract ]

Among estuarine habitats, mangroves are widely considered valuable to both fish and human beings due to their ecosystem services, e.g. acting as nursery site to juvenile fish. Accordingly, much resource has been invested in rehabilitating damaged or planting new mangrove forests. The aim of this study was to assess whether fin fish utilise a completely artificial and protected mangrove habitat. Three inter-tidal mangrove forests dominated by Avicennia marina were selected in southeast Queensland, Australia, for this study: a) a natural site under high human pressures (e.g. road, boating, fishing, residential area); b) a conservation park under low pressure (e.g. tourism); and c) a young man-made protected site under low pressure. Fish species utilising the forests and their size were observed by using underwater cameras. The Shannon index was used to determine species-size diversity (SSDI). The ranges of fish size (min-max) were 1-30, 1-20 and 1-35 (cm) in sites a, b and c, respectively. The SSDI in both natural sites were almost the same (≈ 1.4) while it was the highest (1.8) in the man-made site. The results clearly indicate that fish recruitment is feasible in created mangroves provided that protection is adopted.