|其他题名||Community structure, feeding ecology and movement behaviors of demersal fish around Qiansan Islets|
|导师||杨红生 ; 许强|
|关键词||前三岛 鱼类群落结构 摄食生态 声学遥测 运动行为|
对许氏平鲉持续46天的遥测跟踪研究表明，在研究区域内许氏平鲉具有较高的栖息地忠诚度，栖息地指数为0.90 ± 0.13，而且多数个体在接收器阵列中的一个分区被连续监测到。许氏平鲉信号频次日间显著高于夜间，但连续小波变换分析表明信号频次仅在部分时间段呈现显著昼夜周期(24 h)。栖息地选择指数计算结果表明许氏平鲉对自然岩礁、人工鱼礁分布的砂底和砾石底具有偏好性。许氏平鲉垂直移动主要表现为底栖习性，且垂直移动具有昼夜周期、半日周期和无周期性三种模式。该研究结果对采捕许氏平鲉、海洋保护区的圈定以及关键栖息地的识别具有重要意义，对许氏平鲉的可持续利用和深入研究具有借鉴性意义。
|其他摘要||Since the 20th century, overexploitation on marine organisms and developments of other marine industries, have caused the continuing marine defaunation around the globe. The fishery resource decay in coastal areas (e.g. Haizhou Bay) is notable in fish stocks declining and habitats lost. For sustainable fishery development, a great amount of stock recovery efforts, including the delineation of Marine Protected Area, deployments of artificial reefs to recover damaged habitats, and establishing measures on protective management, have been taken globally.|
The restoration of marine resources around Qiansan Islets in Haizhou Bay has been being carried out since 2005. However, after such restoration efforts, there was no systemic investigation of fishery resource around Qiansan Islets. A series of sampling survey on demersal fish around Qiansan Islets were taken from May 2013 to April 2014 and all caught fish were identified to 22 species 15 families 6 orders: perennial rockfish species (PRS), including Hexagrammos otakii, Sebastes schlegelii, Hexagrammos agrammus, Conger myriaster and etc. are dominant species; Chinese temperate sea bass Lateolabrax maculatus, pacific cod Gadus macrocephalus and species of Carangidae and Scombridae are seasonal migrational species (SMS). The results of canonical correspondence analysis (CCA), which was used to analyzed the effect of environmental factors on fish community structure, suggest that the distribution of fish are mainly influenced by bottom water temperature and dissolved oxygen in bottom water. The bottom water temperature has a positive effect on the biomass of H. agrammus, Pterogobius zacalles, Paralichthys olivaceus, Sebastes hubbsi, Scomber japonicus and Seriola dumerili. The biomass of both G. macrocephalus and H. otakii is of close relationship with dissolved oxygen in bottom water, and G. macrocephalus was only distributed in deep water of high dissolved oxygen in seasons of low temperature. Species of S. schlegelii, C. myriaster and S. pachycephalus were distributed widely in the study area.
Through stomach analysis and stable carbon and nitrogen isotope analysis, we studyed the feeding ecology of H. agrammus, H. otakii, S. schlegelii (three rockfish species) and the migrational species L. maculatus. The results revealed that H. agrammus and H. otakii mainly fed on crabs, fish and amphipoda, and also ate shrimps and polychaeta. S. schlegelii and L. maculatus consumed a high proportion of fish and shrimps. Schoener’s index suggested no significant dietary overlap among the four species, and one way analysis of similarity (ANOSIM) indicated significant dietary differences among species. δ15N and δ13C of L. maculatus were significantly higher than the other three rockfish species, which indicate that the trophic niche differed significantly between L. maculatus and the rockfish species. The overlapped δ15N range and δ13C range, lower Schoener’s index (< 0.6) and significant food composition differences (by ANOSIM) among the three rockfish species, indicated that they had simmilary trophich niches, especially for S. schlegelii and H. otakii, but partitioned in prey resources.
A short-term (with a tracking period of up to 46 d) acoustic tracking was conducted on the black rockfish S. schlegeli. The average residence index (the ratio of detected days to the total period from release to the last detection) in the study area was 0.92 ± 0.13, and most of the tagged fish were detected by only one region of the acoustic receiver array, suggesting relatively high site fidelity to the study area. Acoustic tracking also suggested that this species is more frequently detected during the day than at night in our study area. However, the diel detection periodicity (24 h) was only evident for certain periods of the tracking time, as revealed by a continuous wavelet transform. The habitat selection index of tagged S. schlegelii suggested that S. schlegelii preferred natural reefs, mixed sand/artificial reef bottoms and mixed bottoms of boulder, cobble, gravel and artificial reefs. The vertical movement of tagged S. schlegelii was mostly characterized by bottom dwelling behavior, and there was high individual variability in the vertical migration pattern. Our results have important implications for S. schlegelii catchability, the implementation of marine protected areas, and the identification of key species habitats, and our study provides novel information for future studies on the sustainability of this important marine resource in eastern China.
|张迎秋. 前三岛海域底层鱼类群落结构、摄食生态和运动行为特征[D]. 北京. 中国科学院大学,2015.|
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