赤潮灾害对水产养殖业损失的分级评估

通过分析赤潮灾害损失的构成,建立了一套新的赤潮灾害对水产养殖业损失的评估方法,分别对养殖业的直接经济损失,间接经济损失,赤潮恢复费用等3个方面进行评估,并根据对灾害评估时间要求的不同,将赤潮灾害对养殖业的经济损失评估由粗评到细评,由定性到定量划分为3个等级,即灾前损失预评估,灾时损失评估和灾后损失实评估。最后利用2005年6月发生在浙江南麂列岛赤潮造成水产养殖业灾害损失的实地调查资料,运用建立的分类分级标准进行灾害损失评估。结果表明,此次赤潮属于中型鱼毒赤潮,其直接经济损失为3 100万元,总损失为4 290万元。     

赤潮对浙江省海洋渔业的危害及防治对策

赤潮是一种严重的海洋灾害,它不仅污染海洋生态环境,更会给海洋经济造成严重损失。浙江海域是赤潮的多发区,据统计,2001～2009年浙江海域共发现赤潮287起,累计面积约80000km2,其中有毒有害赤潮达38     

厦门西海域裸甲藻和原甲藻赤潮的观察

对近年来发生在厦门海域的裸甲藻(Gymnodinuum)和原甲藻(Prorocentrum)赤潮的发生情况进行了监测分析,采用了采样、分离、单种培养、显微镜和扫描电镜观察、rDNA序列分析等系列监测、分离培养和赤潮生物鉴定技术,重点观察并确证了厦门海域存在的赤潮原因种为微小原甲藻(Prorocentrum minimum)、Takayama pulchellum、无纹环沟藻(Gyrodinium instriatum).光学显微镜观察表明,赤潮发生海域存在着许多原甲藻和裸甲藻种类,但不能进一步确认到种.利用电子显微镜观察,可根据微小原甲藻体表规则的花纹等特征,根据Takayama pulchellum具有明显的特异性反S形顶沟等特征分别对它们进行有效地分类鉴定.分子分类学分析表明,T.pulchellum(株名为TPXM)28S rDNA D1-D2区序列长度为721 bp,与基因库中同种相似株的同源性大于99%;微小原甲藻(株名PMDH)的ITS和28S rDNA序列与基因库中同种序列的同源性高达99%;无纹环沟藻(株名GIXM)的ITS与基因库中登记的分离自中国深圳海域的4株同种藻的同源性也高达99%.用ITS序列和28S rDNA序列建立的系统进化树也能很好地显示微小原甲藻、Takayama pulchellum、无纹环沟藻之间以及它们与其他藻之间的亲缘关系.将上述结果结合文献记录和环境条件进行了分析,证实这3种赤潮种类Takayama pulchellum、无纹环沟藻、微小原甲藻是厦门海域较为常见的赤潮原因种.对上述检测和鉴定方法的系统应用也表明,这些方法可应用于对现场赤潮生物进行有效监测.     

The Moray Firth Seal Management Plan: an adaptive framework for balancing the conservation of seals,salmon, fisheries and wildlife tourism in the UK

• 1. Within the Moray Firth, north‐east Scotland, there is a history of conflict between seals and salmon fisheries. Under the UK's Conservation of Seals Act 1970 (CoSA) seals are shot to protect fisheries. In 1999 six rivers in the Moray Firth were designated as Special Areas of Conservation (SACs) for Atlantic salmon under the EU Habitats Directive, and in 2000 an SAC for harbour seals was designated in the Dornoch Firth.
• 2. In the 1990s salmon stocks declined. Fisheries managers believed the decline was partly caused by seal predation and consequently increased shooting effort. In years 1993–2003 Moray Firth harbour seal numbers declined possibly due to shooting, posing a potential threat to the status of the Dornoch Firth SAC. Meanwhile wildlife tourism based on marine mammals has increased. The declines in salmon and harbour seals, and the implementation of the Habitats Directive forced a watershed in the approach of statutory authorities to managing seals, salmon and tourism.
• 3. In years 2002–2005 local District Salmon Fishery Boards, the Scottish Executive, Scottish Natural Heritage and stakeholders negotiated a pilot Moray Firth Seal Management Plan to restore the favourable conservation status of seal and salmon SACs, and to reduce shooting of harbour seals and seal predation on salmon.
• 4. Key facets of the plan are the management of the Moray Firth region under a CoSA Conservation Order; application of the Potential Biological Removal concept to identify a limit of seals to be killed; management areas where removal of seals is targeted to protect salmon, while avoiding seal pupping and tourism sites; a training and reporting system for marksmen; a research programme, and a framework allowing an annual review of the plan.
• 5. The plan was introduced in April 2005. A maximum limit of 60 harbour and 70 grey seals was set. Forty‐six harbour and 33 grey seals were killed in 2005 while in 2006 these figures were 16 and 42 respectively. Although the numbers killed were below the maximum limits in both years the returns raised questions about the plan's ability to manage seal shooting at netting stations. The plan provides a useful adaptive co‐management framework for balancing seal and salmon conservation with the protection of fisheries and/or fish farms and tourism for application in the UK and internationally.

Copyright © 2008 John Wiley & Sons, Ltd.