Pelagic fish and shark survivability in recreational fisheries - Biological Sciences PhD Studentship (NERC GW4+ DTP funded)

在英国，估计有88.4万名渔民（2012年）在休闲钓鱼上花费了400多万个钓鱼日，直接消费达8.31亿英镑。这一努力的一部分是针对捕捞和释放休闲渔业。对于一些大型远洋鱼类和鲨鱼物种，由于数量急剧下降（例如鼠鲨），禁止商业登陆。相比之下，休闲捕捞和释放渔业在很大程度上是不受监管的（尽管利益相关者团体可以根据其成员制定参与规则），而且人们对这些活动对生态系统的生态后果知之甚少。因此，了解在休闲捕捞和放生渔业中捕获的大型远洋鱼类在放生后的行为和存活情况，将有助于i)通过改进处理和放生的良好实践技术来加强保护措施，ii)帮助提供这些动物提供的关键生态系统服务（确保这些动物有最好的生存机会）。目前缺乏对生存能力的理解尤其具有挑战性，因为休闲捕捞和释放渔业经常被宣传为一种可持续的活动，然而在英国水域，这种做法的影响在很大程度上是未知的。现有文献表明，捕捞和处理方法的可变性以及宿主环境（如水温）可显著影响放生后的存活率。然而，这些因素对生存能力的贡献程度，以及捕获-释放过程的哪些方面最有机会提供基于证据的生存改善，都需要进行科学调查。

In the UK, recreational fishing effort expended by an estimated 884,000 fishers in England [in 2012] represented more than 4 million fishing days, and £831 million direct spend. A portion of this effort is directed towards the catch-and-release recreational fishing industry. For some large pelagic fish and shark species, prohibitions on commercial landing exist due to precipitous declines (e.g. porbeagle). By comparison, recreational catch-and-release fisheries are largely unregulated (although stakeholder groups can enact rules of engagement upon their membership), and the ecological consequences of these activities for ecosystems are poorly understood. Knowledge on the post-release behaviour and survivorship of large pelagic fish caught in recreational catch-and-release fisheries will therefore be i) valuable to enhance conservation measures through the refinement of good practice techniques for handling and releasing, and ii) aid delivery of key ecosystem services provided by these animals (by ensuring these animals have the best chance of survival). The current lack of understanding on survivability is particularly challenging as recreational catch-and-release fisheries are often promoted as a sustainable activity, yet in UK waters the effects of this practice is largely unknown. Existing literature suggests variability in fishing and handling practices along with the host environment (e.g. water temperature) can significantly influence post-release survivorship. However, to what degree each of these factors contribute to survivability and which aspects of the catch-release process have the greatest opportunity to deliver evidence-based improvements in survivorship requires scientific investigation.