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

在英国，估计有884,000名渔民[2012年]在休闲捕鱼方面花费了400多万天，直接花费了8.31亿GB。这一努力的一部分是针对捕获式休闲捕鱼业。对于一些大型中上层鱼类和鲨鱼物种，由于急剧下降(如鼠海豚)，商业登陆被禁止。相比之下，休闲捕捞和放流渔业在很大程度上是不受监管的(尽管利益攸关方团体可以在其成员加入后制定接洽规则)，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流渔业中捕获的大型中上层鱼类的放生后行为和存活情况，对于通过完善处理和放流的良好做法技术加强养护措施很有价值，以及ii)帮助提供这些动物提供的关键生态系统服务(通过确保这些动物有最好的生存机会)。目前对生存能力缺乏了解尤其具有挑战性，因为休闲捕捞和放生渔业往往被作为一种可持续活动来推广，但在英国水域，这种做法的影响在很大程度上是未知的。现有文献表明，捕捞和处理方法以及宿主环境(如水温)的可变性可显著影响放生后的存活率。然而，这些因素中的每一个在多大程度上有助于生存，以及渔获物释放过程的哪些方面最有机会提供以证据为基础的生存改善，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.