A methodology for recruiting a giant clam, Tridacna maxima, directly to natural substrata: A first step in reversing functional extinctions?

作者：Waters Charles G^*; Story Richard; Costello Mark J

来源：Biological Conservation, 2013, 160: 19-24.

DOI：10.1016/j.biocon.2012.12.036

• Bivalve
• Marine
• Restoration
• Survival

Many coral reef ecosystems throughout the Indo-Pacific and Oceania are experiencing rapid declines and local extinctions of Tridacna species of giant clam, a commercially harvested and ecologically significant bivalve. Tridacna maxima, once numerous in the Aitutaki lagoon (Cook Islands), are now too rare to be reproductively viable and are therefore considered functionally extinct. This paper describes a methodology for restocking juvenile T. maxima directly to coral substrata. One-, two- and 3-year-old T. maxima were equally distributed to protective enclosures designed to mitigate the effects of predation and water turbulence on recruits during early stages of settlement. After 18 days, survival of 3-year-old T. maxima in experimental enclosures was 100%, 96% and 76% compared to 40% in control conditions, but survival of 1-year-olds was 40%, 54%, and 63% compared to 15% in control conditions. Survival of 2-year-olds in enclosures was 100% across all experimental treatments, but a predation event in the control resulted in 96% mortality within 48 h. We concluded that two- and 3-year-old T. maxima are a suitable size for recruitment directly to coral substrata if protected for up to 18 days in the described enclosures. The application of these methods will aid in reversing the functional extinction of T. maxima and develop a more sustainable conservation-based fishery.

• 出版日期2013-4