嵊泗马鞍列岛海洋特别保护区褐菖鲉摄食生境选择

Rocky reef and kelp beds at coastal areas are generally characterized by high productivity and recognized as important nursery habitat for variety marine fish species, especially for rocky reef fish by providing shelters and nursery grounds. These habitats are interlinked mainly through fish feeding activities, which is most critical for the habitat preference of rocky reef fish. Knowledge of feeding habitat selection is fundamental in developing sound management and conservation strategies. The rockfish Sebastiscus marmoratus is one of the protected species in the Shengsi Ma’an special marine protected area and plays an important role in the food web. But so far, there is no study had been reported on the feeding habitat preference of S. marmoratus. In the present study, gut content analysis and stable isotope analysis will be used to compare different feeding ecology of S. marmoratus at three typical habitats, including rocky reef, kelp beds and open water near rocky shore. This study is supposed to answer the following questions: 1) Is there any significant difference among three habitats based on the stable isotope signature of S. marmoratus and prey items? 2) Which habitat does S. marmoratus prefers as feeding area, is there any ontogenetic change in feeding habitat selection? 3) Contribution from each of the three different feeding habitats to the diet of S. marmoratus. Based on that, feeding habitat selection mechanism of S. marmoratus would be discussed. Results of this study are supposed to provide scientific basis for the protection and management of marine fish and their habitat at special marine protected areas.

沿岸水域的岩礁区和海藻场等生境具有较高的初级生产力，能够为是众多海洋鱼类尤其是岩礁性鱼类提供庇护所和养育场所，这些生境主要通过鱼类的摄食活动联系在一起，摄食生境是鱼类最重要的关键生境之一，掌握鱼类摄食生境选择是完善管理和保护措施的基础。褐菖鲉是嵊泗马鞍列岛海洋特别保护区的保护物种，在当地海域食物网中具有重要的作用，主要分布在保护区的岩礁和海藻场等生境中，目前还没有关于褐菖鲉选择哪个生境作为摄食生境的研究，本项目运用胃含物分析和稳定同位素示踪法，对比分析岩礁、海藻场和岩礁周边开阔水域3种典型生境中褐菖鲉群体的摄食生态及其与生境环境、饵料生物之间的相关关系，阐明基于褐菖鲉生长周期的摄食生境选择机制、不同摄食生境为褐菖鲉生长发育所需能量供给的贡献。本项目成果可为海洋特别保护区海洋生物及其生境的保护和规划提供科学依据。

摄食生境是鱼类最重要的关键生境之一，鱼类摄食生境选择研究有助于明确生境的生态功能和鱼类的生境偏好，对于开展海洋生物资源增殖、建立和实施基于生态系统的资源管理保护措施具有重要的指导意义。本项目以嵊泗马鞍列岛海洋特别保护区褐菖鲉的摄食生境选择为主题，开展了典型生境物理环境和生物群落特征、褐菖鲉群体基础生物学特征和摄食生态和褐菖鲉潜在饵料生物组成及碳氮稳定同位素特征研究，系统分析了典型生境褐菖鲉摄食生境选择。主要研究结果为：1. 除贻贝养殖区外，褐菖鲉是其他各生境中的优势种类，尤其是海藻场，贻贝筏式养殖区主要为褐菖鲉幼体提供栖息场所。春季幼鱼的适宜水深为6m，成鱼的适宜水深为8-12m。2.褐菖鲉摄食生境随生长发生变化，通过综合分析褐菖鲉典型生境的环境特征及褐菖鲉群体组成、摄食习性和饵料生物，得出褐菖鲉体长小于7.0cm时，岩礁、海藻场和贻贝筏式养殖区是主要的摄食生境，体长≥7.0cm时，摄食生境转变为岩礁和海藻场，海洋牧场为体长范围10.0~13.9 cm的部分群体提供摄食生境，而体长<10 cm和≥14.0 cm两个群体为周边岩礁生境后续补充到海洋牧场区。研究结果可为明确海洋特别保护区典型生境对生物资源的养护机制提供理论基础，为保护区内生物资源的保护、可持续利用及管理提供科学依据。