广西珍珠湾红树林区中华乌塘鳢的时空分布特征

Temporal and Spatial Variation of Popilation of Bostrychus sinensis in the Mangrove Area of Pearl Bay,Guangxi

为了解广西珍珠湾红树林区中华乌塘鳢的天然资源量及其时空变化动态,为红树林生态系统生物多样性的保护和修复提供基础数据,本研究在广西珍珠湾红树林区的内、中、外滩各设置一个圆形封闭定置围网,于2013年的4季度(1月、4月、7月、10月)各选择3 d投放被标志的中华乌塘鳢(Bostrychus sinensis,区别于野生鱼)至围网中,并在次日用诱捕网捕获,基于标志重捕法的原理评估野生中华乌塘鳢的天然资源量。结果显示,珍珠湾红树林区中华乌塘鳢的全年平均种群密度为(18.74±4.04)ind./hm^(2),平均生物量为(1.44±0.37)kg/hm^(2),其中1月的生物量显著高于10月,其余时间的种群密度和生物量均无显著差异;其种群密度和生物量在红树林中无显著空间差异。红树林为中华乌塘鳢提供繁育场,生境的破坏和过度捕捞导致中华乌塘鳢天然资源量下降,应加强监管、保护和相关研究,促进中华乌塘鳢资源的恢复。

In order to understand the natural resource amount and its temporal and spatial variation dynamics of Bostrychus sinensis in the mangrove area of Pearl Bay,Guangxi,and provide basic data for the protection and restoration of biodiversity in mangrove ecosystem,a circular closed fixed fence was set up in the inner,middle and outer beaches of the mangrove area of Pearl Bay,Guangxi.In the fourth quarter of 2013(January,April,July and October),the marked Bostrychus sinensis(distinguished from wild fish)was put into the fence for three days,and captured by the trap net on the next day.The natural resource amount of wild B.sinensis was evaluated based on the principle of the mark-recapture method.The results showed that the annual average population density of B.sinensis in Pearl Bay mangrove area was(18.74±4.04)ind./hm^(2),and the average biomass was(1.44±0.37)kg/hm^(2).The biomass in January was significantly higher than that in October,and there was no significant difference in population density and biomass in other time.The population density and biomass had no significant spatial difference in mangrove areas.Mangrove areas provide breeding grounds for B.sinensis.However,the destruction of habitats and overfishing has led to the decline of natural resources of B.sinensis.Therefore,supervision,protection and related research should be strengthened to promote the recovery of B.sinensis resources.