Making the most of monkfish and megrim: survey-based assessments and sustainable exploitation

角鱼(Lophius spp.)又称康鱼，是欧洲最有价值的两种鱼类资源。在这项全额资助的博士生项目中，学生将出海调查鳗鱼和巨鳗，并使用15年的时间序列调查数据，以确定这些神秘鱼类的状况并就可持续管理提出建议。该项目是该项目的一部分，总部设在阿伯丁大学。该大学位于苏格兰东北部，通过国际机场与欧洲其他地区建立了良好的联系，是一个充满活力的海洋生物研究社区的所在地，其中包括苏格兰海洋科学研究所(MSS)，这是苏格兰政府的主要咨询机构，也是该项目的合作伙伴。这所大学位于市中心附近，就在海岸边，有几英里长的沙滩。它还靠近英国最大的国家公园，为对野生动物和海洋环境感兴趣的学生提供了梦幻般的生活方式。大多数英国渔民捕获的角鱼没有对北部大陆架上它们的丰度进行公认的科学评估；也没有可供其可持续管理使用的参考点。自2005年以来，MSS每年都会进行一系列关于鳗鱼的调查(Fernandes等人)。2007)。这些调查的独特之处在于，这些调查是与捕鱼业合作并使用来自渔业的船只进行的。它们也是独一无二的，因为它们提供了对角鱼绝对丰度的估计(Reid等人。还包括另一个有价值的物种，即鳞毛虫(鳞毛虫属)，对此只有相对的科学评估。最近的一次国际基准活动没有结果，仍然根据调查生物量估计(“第3类种群”)来管理种群，因此不知道适当的开采率。MSS正在开发以长度为基础的方法，以提高关于天使鱼的建议的科学基础。在这项研究中，目的是通过开发一个基于年龄的评估模型来补充这项工作，该模型由Fernandes(ICES 2013)提出，特别注意该模型对任何年龄阅读偏差和错误的敏感性。还将通过分析国际底拖网调查的适当数据，考虑模型对调查覆盖范围的敏感性。这些评估方法将得到补充，纳入对年龄、长度和性别的成熟度的检查；以及调查年龄、长度和性别的自然死亡率。一旦完善了基于年龄的模型，学生还将进行管理策略评估(MSE)，以根据ICES程序确定适当的捕鱼和生物量参考点。基于长度的方法也可以应用于megrim。最后，有充分的理由怀疑，角鱼，特别是黑腹鱼(Lophius Budes Assa)，这是一种温暖的水域物种，也可能受益于气候变化导致的气温上升。因此，随着海洋温度的变化，还可以检测到这些物种的丰度和分布的变化。数据将取自MSS(Clarke)提供的天使鱼调查的时间序列。费尔南德斯将通过阿伯丁大学的专门课程和国际教育、科学及科学理事会的培训课程(MSE)提供建模和统计编程(R)方面的培训。该学生将在学籍的头两年参加鳗鱼调查，这将增加可用的时间序列。这名学生还将参加位于哥本哈根ICES总部的ICES凯尔特海工作组，介绍他们的工作。

Anglerfish (Lophius spp.), also known as monkfish, and megrim are two of the most valuable fish resources in Europe. In this fully funded PhD studentship, the student will take to sea to survey anglerfish and megrim, and use a 15 year time series of survey data, to determine the status and advise on the sustainable management of these enigmatic fish species. The studentship is part of the MASTS SUPER DTP and is based at the University of Aberdeen. Located in the North East of Scotland, with good links to the rest of Europe through an international airport, the university is home to a vibrant marine biology research community, which includes Marine Scotland Science (MSS), the principal advisory agency to the Scottish government and a partner in this project. The university is located close to the city centre, which is right on the coast with miles of sandy beaches. It is also close to the UK's biggest national park, offering a fantastic lifestyle for students interested in wildlife and the marine environment. The anglerfish caught by most UK fishermen have no accepted scientific assessment of their abundance on the northern shelf; nor are there reference points available for use in their sustainable management. A series of surveys, dedicated to anglerfish have been carried out annually by MSS since 2005 (Fernandes et al. 2007). These surveys are unique in being carried out in collaboration with, and using vessels from, the fishing industry. They are also unique in providing an absolute abundance estimate of anglerfish (Reid et al. 2007) and also include another valuable species, the megrim (Lepidorhombus spp.), for which there is only a relative scientific assessment. A recent international benchmark exercise for the scientific assessment of anglerfish was inconclusive and the stock is still managed on the basis of the survey biomass estimates ("category 3 stock") such that appropriate exploitation rates are unknown. MSS are developing length based approaches to improve the scientific basis of the advice on anglerfish. In this studentship the aim is to complement this work by developing an age-based assessment model, previously proposed by Fernandes (ICES 2013), paying particular attention to the sensitivity of the model to any age reading bias and error. Sensitivity of the model to survey coverage will also be considered, by analysing appropriate data from the International Bottom Trawl Survey. These assessment approaches will be complemented by incorporating an examination of maturity at age, length and sex; as well as investigating the natural mortality at age, length and sex. Once the age based model has been refined, the student will also conduct a management strategy evaluation (MSE) to determine appropriate fishing and biomass reference points in accordance with ICES procedures. There is also scope to apply the length based method to megrim. Finally, there is good reason to suspect that anglerfish, particularly the black bellied species (Lophius budegassa) which is a Lusitanian (warm water) species, may also benefit from increasing temperatures due to climate change. So there is also scope to detect changes in the abundance and distribution of these species in relation to changes in sea temperature. Data will be taken from the time series of anglerfish surveys available from MSS (Clarke). Training will be provided in modelling and statistical programming (R) by Fernandes, through dedicated courses at the University of Aberdeen, and at ICES training courses (MSE). The student will participate in the anglerfish surveys in the first two years of the studentship which will augment the time series available. The student will also attend the ICES Celtic Seas Working Group at ICES HQ in Copenhagen to present their work.