莱州湾4种大型甲壳类的空间与营养生态位

根据2010—2019年夏季莱州湾底拖网调查数据,研究了4种大型甲壳类(中国明对虾、三疣梭子蟹、日本蟳和口虾蛄)的优势度、种间联结、空间生态位特征,并应用碳氮稳定同位素数据分析了4种大型甲壳类的营养级、营养生态位与摄食来源。结果显示,口虾蛄、日本蟳是目前莱州湾夏季甲壳类最主要的优势种,放流种类中国明对虾、三疣梭子蟹为群落的重要种;4种大型甲壳类的种间联结性不强,显著正联结主要出现于中国明对虾与其他三者之间;日本蟳空间生态位宽度最高(2.45),口虾蛄(2.13)次之,中国明对虾(1.92)和三疣梭子蟹(1.93)较低;生态位重叠较高主要发生于中国明对虾与其他3种之间;4种大型甲壳类营养级相近(3.02～3.28),中国明对虾生态位总面积最大,三疣梭子蟹与日本蟳、口虾蛄的生态位总面积相近,三疣梭子蟹和日本蟳的营养生态位重叠较高;摄食来源分析表明,中国明对虾摄食双壳类比例更高,其他3种摄食来源同质化程度较高。目前莱州湾三疣梭子蟹和中国明对虾的优势度低于口虾蛄和日本蟳,表明增殖放流虽然扩大了三疣梭子蟹和中国明对虾的种群规模,但尚未较大程度改变甲壳类群落结构。综合4种甲壳类的群落地位、种间联结性、空间生态位宽度与重叠、营养级与营养生态位以及摄食来源的研究结果,中国明对虾与其他三者竞争相对较小,而三疣梭子蟹与日本蟳、口虾蛄竞争较大。为最大程度发挥增殖效益,建议在确定放流地点和放流数量时,应着重考虑相近生态位物种对放流物种的竞争和限制。     

胶州湾鱼类生物量粒径谱特征

为了解胶州湾海域鱼类群落粒径结构特征,本研究根据2016-2017年4次底拖网调查数据构建了胶州湾鱼类生物量粒径谱,比较分析了各季节鱼类生物量粒径谱特征参数的异质性。结果显示,胶州湾Sheldon型鱼类生物量粒径谱呈现单峰模式,鱼类粒径范围为-3~10粒径级,粒径分布相对均匀,且峰值位于5~6粒径级,主要由大泷六线鱼和褐菖鲉等小型鱼类构成。各季节鱼类标准化生物量粒径谱曲率和曲度差异显著,其中春季曲率最大且曲线较平缓,夏季曲率最小且曲线相对陡峭。谱线曲度和曲率的季节变化主要与粒径小的细纹狮子鱼、大泷六线鱼、玉筋鱼及长丝虾虎鱼等地方常栖性种类和赤鼻棱鳀、白姑鱼等季节洄游性种类的出现有关。Abundance-biomass comparison(ABC)曲线表明,春季处于未干扰状态,冬季处于中度干扰状态,夏秋季处于严重干扰状态。研究表明,胶州湾鱼类群落总体处于严重干扰状态,鱼类生物量谱呈现单峰型,粒径结构以小型粒径鱼类为主,且地方常栖性和季节洄游性鱼类等补充群体的数量和粒径大小影响鱼类生物量粒径谱的峰型和曲率。     

Effects of tidal flat reclamation on sediment quality and hypoxia in Isahaya Bay

• 1. Ariake Bay, which is located in western Japan, has a large tidal range (>6 m) and a vast tidal flat (200 km²). In the early 1990s, the government‐managed Isahaya Reclamation Project began in the western part of Ariake Bay. A 16‐km² area of tidal flat in the inner part of Isahaya Bay was destroyed through reclamation and separated from the sea by a dyke, which created land and a freshwater reservoir.
• 2. Since the initiation of the project, fishery yields around Isahaya Bay have dramatically decreased. The objective of this study was to clarify the relationship between the work associated with the Isahaya Reclamation Project and the recent environmental deterioration in Ariake Bay, with references to present sediment thickness and organic matter content, and hypoxic water distributions in Isahaya Bay.
• 3. The organic matter load from the reservoir has increased since the initiation of the reclamation project and has been associated with a thick layer of fine sediment at the bottom of Isahaya Bay. The thickness of fine sediment and the total organic carbon content were higher in Isahaya Bay than in the freshwater reservoir.
• 4. Based on measurements in August 2001, hypoxic water spread widely in and around Isahaya Bay; the lowest dissolved oxygen (DO) concentration (0.53 mg L^?1) was observed just outside the dyke. An analysis based on a two‐layered box model using data obtained in August 2001 showed that the DO consumption rate in the bottom layer was high (0.61 mg O₂ L^?1 day^?1), and that 22–41% of the total organic carbon load needed to induce the hypoxic water was derived from the reclamation area.
• 5. Our findings strongly suggest that enclosed seas may suffer from eutrophic and hypoxic conditions because of their low seawater‐exchange rate. A comprehensive conservation programme and environmental assessment including physical and material transport processes in the system is needed to manage the environment of the enclosed sea.

Copyright © 2005 John Wiley & Sons, Ltd.     

粤港澳大湾区背景下高职校企协同育人的对策研究

随着粤港澳大湾区战略规划的发布和推进,将粤港澳大湾区打造成为教育和人才高地,粤港澳大湾区职业教育发展迎来了历史性机遇。在粤港澳大湾区背景下,提出了高职院校的发展需要三地政府企业学校和社会共同合作,引进先进的职教理念,加强职业教育与产业发展无缝对接,调动行业企业参与职业教育的积极性,发挥各自的资源优势,优化资源配置和功能整合,协同培养适应经济发展需要的高素质技术技能人才,为大湾区经济建设与社会发展提供有力的人力支撑。     

影响海湾扇贝中间育成效果的因素探讨

影响海湾扇贝中间育成效果的主要因素有:育成器具种类(A)、换袋时间(B)、网孔大小(C)和装苗量(D)。正交试验和方差试验表明,A、C、D为提高保苗率的敏感因素,B、C、D为提高生长效果的显著因素。试验结果提出:网箱或圆锥形袋的保苗率明显优于扁袋;每隔15～30天更换一次网袋可显著加快贝苗的生长速度,网孔大小以2mm为适宜,每袋最终实际装苗量应在2000只以内。     

Comparison of spatiotemporal patterns in reproduction of the kuruma prawn Marsupenaeus japonicus between two regions having different geographic conditions in Kyushu, southern Japan

ABSTRACT:   The Yatsushiro Sea and Shibushi Bay are, respectively, located on the western and south-eastern coast of Kyushu, southern Japan. The Yatsushiro Sea is a shallow semi-enclosed inland sea, whereas Shibushi Bay is an open-type bay with a deep and wide mouth facing the open sea. The size at sexual maturity and spatiotemporal patterns of reproduction of the kuruma prawn Marsupenaeus japonicus (Decapoda, Penaeidae) were examined and compared between these two regions. In the Yatsushiro Sea, the size at sexual maturity was estimated to be 131 mm body length. However, the estimated size at sexual maturity was considerably larger (154 mm) in Shibushi Bay. The spawning season of M. japonicus was estimated to continue from April to September in the Yatsushiro Sea, whereas it was estimated to be longer in Shibushi Bay, from March to November. It is believed that the warm water temperature due to the strong effect of the Kuroshio Current prolonged the spawning season of M. japonicus in Shibushi Bay. The spawning grounds were estimated to be in areas deeper than 10 m in the Yatsushiro Sea and deeper than 20 m in Shibushi Bay. In Shibushi Bay, body size distribution of mature females was considered to be less affected by water depth in comparison with the Yatsushiro Sea, although older mature females larger than 200 mm body length also spawned outside of the bay.     

杨梅果实挥发油的气-质联用分析

首次对新鲜和贮藏的木叶杨梅(Myrica rubra Sieb.et Zucc.)果实挥发油(volatile oils)进行了GC-MS联用分析比较。新鲜果实挥发油分离得到58个色谱峰,从中鉴定出49种成分,占挥发油相对含量的96.03%;3～5℃贮藏5 d后的果实挥发油分离得到66个色谱峰,从中鉴定出57种成分,占挥发油相对含量的87.17%。木叶杨梅果实中因含大量单萜及倍半萜而带有浓郁的甜香、花香和木香。杨梅贮藏过程中挥发油萜类化合物种类和含量变化明显,使杨梅的香气、口感发生改变,新鲜度降低。贮藏过程中具有抗菌作用化合物的消失和含量的减少,使杨梅果实抗菌防腐能力降低。研究结果为杨梅果实的保鲜、加工和开发提供了参考依据。     

Relationships between watershed Stressors and sediment contamination in Chesapeake Bay estuaries

Three methods for assessing the relationships between estuarine sediment contaminant levels and watershed Stressors for 25 Chesapeake Bay sub-estuaries were compared. A geographic information system (GIS) was used to delineate watersheds for each sub-estuary and analyze land use pattern (area and location of developed, herbaceous and forested land) and point source pollution (annual outflow and contaminant loading) using three landscape analysis methods: (1) a watershed approach using the watershed of the estuary containing the sampling station. (2) a partial watershed approach using the area of the watershed within a 10 km radius of the sampling station and (3) a weighted partial watershed approach where Stressors within the partial watershed were weighted by the inverse of their linear distance from the sampling station. Nine sediment metals, 16 sediment organics and seven metals loading variables were each reduced to one principal component for statistical analyses. Relationships between the first principal components for sediment metals and organics concentrations and watershed stressor variables were analyzed using rank correlation and stepwise multiple regression techniques. For both metals and organics, the watershed method yieldedR ² values considerably lower than the partial and weighted partial watershed analysis methods. Regression models using Stressor data generated by the weighted partial watershed landscape analysis method explained 76% and 47% of the variation in the first principal component for sediment metals and organics concentrations, respectively. Results suggest that the area of developed land located in the watershed within 10 km of the sediment sampling station is a major contributing factor in the sediment concentrations of both metals and organics.     

闽东滩涂养殖对三都澳环境与资源的影响浅析

闽东三都澳具有与世界名港鹿特丹相媲美的港口资源,其深水航道国内少有,由于多种因素使其作为备用港口,至今未深度开发.闽东利用其丰富的滩涂资源优势发展规模巨大的水产养殖业,如养殖大黄鱼产量占我国大黄鱼产量的80％,这种养殖在一定程度上促进闽东经济的发展.但这种养殖也给闽东三都澳水环境带来严重的影响,造成水体富营养化和沉积速率加大,对该区旅游资源和港口资源的开发使用等影响很大.基于分析,建议该地的滩涂养殖需要重新定位和布局,注重旅游资源和港口资源的今后开发对当地资源与经济的深远影响,对闽东产业转型升级和生态环境保护具有重要意义.     

Damage by monk seals to gear of the artisanal fishery in the Foça Monk Seal Pilot Conservation Area, Turkey

The present study examines the operational interaction between critically endangered monk seals Monachus monachus and artisanal fisheries in the Foça Pilot Monk Seal Conservation Area, Turkey between 1994 and 2002. One to four permanent researchers collected the data on this interaction during the seal sighting data inquiries. Interviews with the fishermen provided 142 direct interactions with monk seals around the fishing gear. Among these encounters damage to fishing gear, including gill nets (53%), trammel nets (37%), longlines (9%) and a lure (1%) was recorded 90 times. However, no difference was found in damage between gill and trammel nets. Although, the damage inflicted by seals per occasion was found to be substantial (maximum 462.5 USD per occasion), the overall annual economic impact on the artisanal fishery was found to be modest. Limitation in soaking time of nets; long-line use instead of nets in MPAs where monk seals survive; and low interest credits to be given to those fishermen who suffer monk seal damage, are proposed as appropriate management practices.