福建省海洋捕捞与渔业资源学科发展的思路

文章首先分析了国内外在海洋渔业资源的调查与评价、海洋渔业资源的保护与管理、海洋环境生态修复和海洋渔业资源的恢复等有关海洋捕捞和渔业资源学科研究的现状和发展趋势,探讨了目前我国海洋渔业面临捕捞过度、渔具选择性差,渔业资源日益衰退等主要问题,提出2个学科的战略目标与发展思路,最后建议目前可以开展的适宜捕捞力量研究、渔具选择...     

The response of coral trout (Plectropomus leopardus) to capture, handling and transport and shallow water stress

The stress response of coral trout (Plectropomus leopardus ) to wild capture or controlled shallow water stressors was investigated. Stress associated with capture from the wild, handling and transport and shallow water evoked significant changes in circulating levels of cortisol, glucose, lactate, haemoglobin (Hb) and haematocrit (Hct) in coral trout. Plasma glucose, Hb and Hct increased over 30 to 60 min in response to the controlled stressor and then returned toward unstressed levels, even if the stressor persisted. Cortisol increased to maximum levels over the 60 min following the onset of the stressor and remained elevated for 4 h in the case of a single 30 min shallow water event or 3 d in response to the capture, handling and transport. The difference between the responses of blood glucose and cortisol suggests that cortisol does not maintain blood glucose during stress in coral trout. The concentrations of circulating thrombocytes, lymphocytes and granulocytes were also significantly affected by shallow water stress. As lymphocytes and granulocytes are important immune components, reduced concentrations of these cells may explain the increases in disease susceptibility, commonly observed in stressed fish during live transport.     

基于Libpcap的数据包捕获机制的实现

网络数据包捕获分析是进行网络安全检测和流量计费的基础。论文研究了以太网数据包监听过滤机制和Libpcap分组捕获函数库,并在Linux平台上设计实现了一个小型的网络数据包的捕获分析器,该捕获分析器运行简单、高效、准确。     

我国海洋捕捞渔业经营机制实证研究

选择全国海洋渔业重点市——浙江省舟山市作为典型,运用经济模型对我国海洋捕捞渔业经营机制的改革与海洋捕捞渔业生产力发展的关系进行了实证分析,并结合目前我国海洋捕捞渔业经营机制中的个体独资经营、股份合作经营和股份制公司存在的制度缺陷,对经济模型分析的结论进行了现实层面的探讨,并提出了进一步完善和创新海洋捕捞渔业经营机制的基本思路。     

大连近海光棘球海胆生殖周期的初步研究

１９９０年对大连近海光棘球海胆生殖腺指数进行周年调查,并对其生殖腺发育进行了组织学观察。结果表明：该海区光棘球海胆的自然系列期为７月末至９月下旬,盛期为８月中下旬至９月上旬,这一时期的水温为２２～２３℃,处于水温自然下降季节。雄性成熟略早于雌性。全年生殖腺肥满期出现在６～８月,消瘦期为１０月至年４月,因而海胆的采捕期以６～８月初为宜。     

Circle hook effectiveness for the mitigation of sea turtle bycatch and capture of target species in a Brazilian pelagic longline fishery

• 1. Incidental catches by the pelagic longline fishery is a major global threat for loggerhead (Caretta caretta) and leatherback (Dermochelys coriacea) sea turtles.
• 2. The reduction of incidental capture and post‐release mortality of sea turtles in the Brazilian pelagic longline fishery, operating in the south‐western Atlantic Ocean, was investigated by comparing the performance of 18/0 circle hooks with 9/0 J‐type (control) hooks. Hook selectivity experiments were performed between 2004 and 2008, in a total of 26 trips, 229 sets and 145 828 hooks. The experimental design included alternating control and experimental hooks along sections of the mainline.
• 3. An overall decrease in capture rates for loggerhead turtles of 55% and for leatherbacks of 65% were observed when using circle hooks. In addition, deep‐hooking in loggerheads decreased significantly from 25% using J‐hooks to 5.8% with circle hooks, potentially increasing post‐release survival.
• 4. Circle hooks increased catch rates of most of the main target species, including tunas (bigeye Thunnus obesus and albacore T. alalunga), and sharks (blue Prionace glauca and requiem sharks of the genus Carcharinus), with no difference in the capture rates of yellowfin tuna (T. albacares), shortfin mako shark (Isurus oxyrinchus), hammerhead sharks (Sphyrna lewini and S. zygaena), and dolphinfish or mahi mahi (Coryphaena hippurus). On the other hand, a significant decrease in the capture rate of swordfish (Xiphias gladius) was detected when using circle hooks.
• 5. Overall, results support the effectiveness of using circle hooks for the conservation of loggerhead and leatherback sea turtles, with positive effects on capture of most target species of the south‐western Atlantic longline fishery. Copyright © 2010 John Wiley & Sons, Ltd.

     

Electrofishing in streams of low water conductivity but high biodiversity value: Challenges,limits and perspectives

Electrofishing in streams of low water conductivity has technical limitations leading to the widespread use of poison fishing. In theory, provided a high enough voltage gradient can be created in water, electrofishing should be possible in all but the lowest of conductivities (<10 µS/cm). Using custom‐made equipment delivering up to 1,500 V DC, tests were carried out in French Guiana on 27 streams with water conductivity as low as 16 µS/cm. Approximately 5,800 fish of 93 species were captured, with an electrofishing mortality rate of 1.83%. Poison treatments were used within enclosed sections to assess how efficient multiple pass electrofishing removal is when assessing species richness and population number. The Chao II estimator on 2 electrofishing passes gave the best results for species richness, but rare species can elude electrofishing. Estimates of total fish abundance (i.e. all species pooled) were possible with the use of depletion models. Capture efficiencies by species were highly biased, however, and abundance could be underestimated for the most difficult species to catch. These results show that with the right equipment and settings, electrofishing can be an efficient alternative to poison fishing surveys in small tropical streams of low water conductivity but high biodiversity value.     

Identifying potential causes of fish declines through local ecological knowledge of fishers in the Ganga River,eastern Bihar,India

Local ecological knowledge (LEK) can offer insights into fisheries management by describing long‐term changes that are difficult to unravel in data‐poor river‐floodplain fisheries. LEK is derived from complex interactions between fishers’ observations of environmental change and their institutional capacities to manage fisheries. Hence, it is important to understand where and how LEK and formal scientific studies on fish species’ decline could complement each other. In this paper, the causes of decline of 58 fish and two shrimp taxa were identified from LEK data (1999–2019) obtained from river–floodplain fisheries of the Gangetic plains (Bihar, India). Qualitative analyses of LEK were used to generate species‐specific hypotheses and historical insights on their declines. Destructive fishing, overfishing and the Farakka barrage were cited by fishers as the major causes of declines. Potential reasons for these perceptions were explored in relation to fishers’ experiences of conflicts in the region over fishing rights and access.     

菩提树黑痣病菌生物学特性及病害发生规律

为了研究菩提树黑痣病的年发生规律、病原菌子囊孢子释放规律及子囊孢子萌发的生物学特性,利用样地调查和实验室测定方法,对广西凭祥市菩提树黑痣病进行了调查。结果表明:菩提树黑痣病病情指数增长量与平均降水量和平均空气相对湿度呈极显著关系,与温度变化呈显著关系,与平均相对孢子捕捉量呈不显著关系。菩提树黑痣病病情指数增长盛期在4-8月,增长高峰期为6月;室外子囊孢子捕捉量在6月、10-11月出现2个高峰期;菩提树黑痣病菌子囊孢子萌发的最适生长温度为25℃,子囊孢子萌发要求的最低空气相对湿度为90%,3种碳源处理都无法刺激子囊孢子萌发,而3种氮源中的硝酸钠处理可以刺激其萌发。