马鞍列岛褐菖鲉Sebasticus marmoratus栖息地适宜性评价

Habitat suitability assessment of Sebasticus marmoratus in the rocky reef region of the Ma'an Archipelago

为了评估趋礁鱼类在岛礁海域的生境适宜度,选取马鞍列岛的褐菖鲉(Sebasticus marmoratus)为指示物种,以2009年获取的水深、盐度、叶绿素a、浊度和底质数据作为褐菖鲉春、冬季栖息地指示因子,建立栖息地适宜度曲线,并计算各站点的栖息地适宜性指数(HSI)。结果显示:1)绿华、花鸟、嵊山沿岸站点HSI普遍较低,枸杞岛、三横山、东库山沿岸站点褐菖鲉HSI相对较高,其中最大值1.0出现在枸杞岛沿岸的站点;2)春季褐菖鲉幼鱼的适宜水深在6 m左右,成鱼适宜在8—12 m的水深处生存;冬季褐菖鲉对8—12 m的水深适宜性良好;3)春季所有褐菖鲉的适宜盐度为30PSU,冬季幼鱼的适宜盐度为27—31PSU,成鱼的适宜盐度为27PSU、31PSU;4)随着叶绿素a和浊度值的增大,褐菖鲉适宜性逐渐降低。底质类型为岩时最适合褐菖鲉生存。5)相关分析显示,褐菖鲉丰度与底质类型相关性最大,而与叶绿素a、浊度呈显著负相关。研究结果表明,初级生产力和浑浊程度越高对褐菖鲉丰度抑制越明显。底质类型是褐菖鲉丰度分布的重要影响因子,其中分布有较多大型海藻的岩礁生境是其最适宜的栖息地。利用2010年春、冬季环境调查和渔获数据进行HSI模型验证,资源丰度随HSI值升高而增加,因此构建的模型可用于趋礁鱼类在岛礁海域的栖息地适宜性分析。

In this study,we selected Sebasticus marmoratus as an indicator species to evaluate the habitat suitability of rocky reef fishes in the Ma＇ an Archipelago. Indicator factors of S. marmoratus＇ s habitat（ i. e. water depth,salinity,chlorophyll a,turbidity,and substrate） were obtained in the spring and winter of 2009. Subsequently,a suitability curve was developed and the Habitat Suitability Index（ HSI） of S. marmoratus at each sampling site was calculated. It is shown from the results that： 1） The HSI of alongshore sites around the Lvhua,Huaniao,and Shengshan Islands are generally low,while those around the Gouqi,Sanheng,and Dongku Islands are relatively high,with the maximum（ 1.0） recorded at the sites around the Gouqi Island; 2） The most suitable water depths in spring are 6 and 8—12 m for the juvenile and adult S.marmoratus,respectively,while during winter,the latter depth is mostly inhabited by S. marmoratus; 3） For spring,the suitable salinity was 30 PSU for all size groups,whereas in winter,it ranges from 27 to 31 PSU for juveniles,and appear to be 27 and 31 PSU for adults; 4） The suitability decreases with increasing chlorophyll a and turbidity,noting the most suitable substrate type as rocky bottom; 5） Correlation analysis shows that the abundance of S. marmoratus is highestcorrelated with sediment type but negatively correlated with both chlorophyll a and turbidity. The results imply that high primary productivity and turbidity may significantly reduce the S. marmoratus population size. Substrate type is the most important factor for S. marmoratus distribution. In particular,the rocky reef habitat occupied by kelp was the best living environment for S. marmoratus. Finally,we verified the HSI model with data from our surveys and fishery production in spring and winter of 2010,which shows that S. marmoratus abundance increases with higher HSI values. Therefore,we are confident that the HSI model we constructed is applicable for assessing the habitat suitability of rocky fishes in rocky reef areas.