Empirical weighting of multiple stock-abundance indices for parameter estimation and stock assessment in a multi-zone or multi-species fishery     

McDonald  A. David; Kendrick  Terese H.; Breen  Paul A. 《ICES Journal of Marine Science》2001,58(1):204-215

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台湾海峡金色小沙丁鱼幼鱼索饵群体研究   总被引：2，自引：1，他引：2  

杨圣云  丘书院 《台湾海峡》1992,11(3):244-250

本文研究了台湾海峡南部和北部的金色小沙丁鱼当年生幼鱼计数性状和量度性状特征差异,并结合其生物学特性、产卵场、洄游及海区环境特征进行综合分析。结果表明,台湾海峡南部和北部的索饵幼鱼仍属于同一地方种群:闽南-台湾浅滩语地方种群。根据其索饵洄游特点,可分为台湾海峡南部和北部两个索饵群体.  相似文献   

Temporal patterns in the structure of macrobenthic communities of an Australian estuary     

Sebastian Rainer 《Estuarine, Coastal and Shelf Science》1981,13(6):597-620

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In Situ Measurement of Pinna nobilis Shells for Age and Growth Studies:
A New Device     

Jos Rafael García‐March  Antonio Manuel García‐Carrascosa  lvaro Luís Pea 《Marine Ecology》2002,23(3):207-217

Abstract. Pinna nobilis Linnaeus 1758 is an endemic bivalve mollusc in the Mediterranean Sea, where it inhabits seagrass meadows, especially Posidonia oceanica (L.) Delile. It is the largest bivalve in the Mediterranean, reaching lengths up to 120 cm. In its natural habitat, P. nobilis lives with the anterior part of the valve buried in the seabed, attached to Posidonia rhizomes by byssus threads.
This habit makes it impossible to measure its total length directly in situ. As the only way to determine the individual age is the relationship between age and total length, several equations have been proposed to estimate total length by relating it to the unburied parts of the shell. Such measurements are essential to ecological studies that consider age, growth, and population dynamics, and that evaluate the environmental factors that affect this species.
Accurately estimating total length depends on the accuracy and precision of the method employed to measure the unburied shell parts. In this paper, we point out the lack of precision of the instruments and methods used until now; we also demonstrate the reason for this imprecision. A new device to measure unburied parts of Pinna nobilis with a precision comparable to that obtained when measuring extracted valves is described. This device is unaffected by substratum type and reduces measurement time. The latter is a very important feature, because these procedures are usually performed whilst SCUBA diving. Finally, a growth equation has been fitted to the measurements obtained with the new device from a population located in Moraira (Alicante, western Mediterranean).  相似文献   

温度变化对刺参同工酶的影响     

纪婷婷  董云伟  董双林 《中国海洋大学学报(自然科学版)》2007,37(4):586-590

采用同工酶电泳方法,对在不同温度处理下刺参(Apostichopus japonicus)的乳酸脱氢酶(LDH)、酯酶(EST)和超氧化歧化酶(SOD)的表达情况进行分析。本文结果显示刺参组织内无LDH同工酶的表达。在10℃到20℃的温度突变处理中,12 h内EST和SOD均有新增酶带,在20℃到10℃的温度突变1 h内EST表达有新增酶带。3 h内SOD表达有新增酶带。在不同变温幅度的处理中,EST和SOD只有1条酶带。这表明,刺参对温度突变可产生积极的响应,对于其适应环境温度的变化具有重要意义。  相似文献   

Bathymetric shift in the distribution of Atlantic surfclams: response to warmer ocean temperature     

Weinberg  James R. 《ICES Journal of Marine Science》2005,62(7):1444-1453

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北黄海盆地区域地质特征   总被引：6，自引：1，他引：6  

田振兴  张训华  薛荣俊 《海洋地质前沿》2004,20(2):8-10

北黄海盆地位于黄海的北部，由于勘探程度低，研究投入少，使得它成为我国迄今为止尚未发现油气的惟一海区。随着我国在南黄海盆地和朝鲜在北黄海盆地东部发现油气，如何实现北黄海盆地油气突破，成为我们研究的焦点。结合该区现有资料和前人研究成果，对北黄海盆地的地球物理场和地质构造特征进行了全面的论述，并在此基础上，对该区油气资源远景作了初步评价。  相似文献   

热带海洋珍珠贝类立克次体(RLO)病研究 Ⅷ.养殖大珠母贝贝苗养成期群体RLO病流行病学研究   总被引：2，自引：0，他引：2       下载免费PDF全文

吴信忠  潘金培  江静波 《海洋学报》2003,25(2):84-94

大珠母贝人工养殖过程中,幼贝死亡是一个严重的问题。1993年11月至1995年5月,采用现场调查、实验室研究和数理分析相结合的方法,在海南省临高县新盈珍珠贝养殖场自然海区吊养的A,B,C3批养殖贝和陵水新村珍珠贝养殖场养殖池吊养的D批养殖贝的发病和死亡情况进行了流行病学凋查.结果显示,大珠母贝幼贝群体的死亡是以暴发性方式发生,幼贝群体的大批量死亡高峰一般发生在4～6月龄期,8个月以后随着龄期的延长,死亡率显著降低.幼贝群体死亡率与贝体平均体长的关系是4cm以下的贝体死亡率较高,1～3cm阶段处于死亡高峰期内,5cm以上的贝体死亡率显著降低.大珠母贝幼贝群体的死亡率与类立克次体感染(即RLO平均感染严重度指数SI)之间存在显著的相关性,在RLO感染的高峰之后或当中部相应伴随贝群体死亡率的高峰,随着RLO感染的降低,贝群体的死亡率也明显降低。在4批养殖贝群体中,仅在A批养殖贝群体样本中发现有少量纤毛虫寄生(感染率为87.5%,感染强度为3.56个/10倍物镜).这几批幼贝群体的死亡与海水温度、盐度之间均无相关性。  相似文献   

基于RS和GIS的唐山沿海地区湿地结构动态监测     

汪高明  邱若峰  SUN Xiaogong 《海洋湖沼通报》2007,(3):35-40

利用历史资料和Landsat TM卫星遥感图像,研究了唐山市沿海地区湿地结构自上世纪80年代以来的演变特征,着重对1987~2004年陡河——滦河之间的湿地结构类型进行了识别,绘制了不同时期的湿地面积解译图。利用Mapinfo制图软件计算出两个时期的面积转化矩阵,对该区主要湿地类型浅海水域、滩涂、芦苇沼泽、水稻田、养殖场、盐田等湿地的面积进行了年份比较,从而分析得出唐山市沿海湿地结构从80年代至今以来破碎化加重,应该加强湿地结构的动态监测。  相似文献   

Temporal change of clustered distribution of planktonic ciliates in Toyama Bay in summers of 1989 and 1990     

Toshikazu Suzuki  Akira Taniguchi 《Journal of Oceanography》1997,53(1):35-40

Temporal change of clustered distribution in vertical profiles of three nutritional groups of planktonic ciliates, e.g. heterotrophic naked ciliates, mixotrophic naked ciliates and heterotrophic loricated ciliates, was investigated by following a drifting buoy in Toyama Bay on the Japan Sea coast of central Japan in summers of 1989 and 1990. Clustered distribution, represented as the mode of population density in the vertical plane, occurred mainly in the oligotrophic upper layer (0–50 m depth) above the subsurface chlorophyll-a maximum layer. Its clustered degree was stronger when the mode of population density in the vertical plane was formed at shallower depth, while its longevity was shorter as mentioned above. Vertical distribution of ciliates during summer in Toyama Bay is characterized by ephemeral clustered distribution, or in other wards, by rapid alternations of appearance and disappearance of the clustered distribution.  相似文献