Interactions between biology, environmental and anthropogenic factors on the exploitation of pelagic species by the Scottish fleet

鲱鱼和鲭鱼是洄游物种，在产卵和/或觅食聚集期间是季节性的目标。这些物种占苏格兰远洋渔业重量的80%，占整个苏格兰渔业重量的55%，占整个苏格兰渔业价值的40%。苏格兰船队由21艘大型（40-85米）现代拖网渔船组成，分布在设得兰、彼得黑德和弗雷泽堡。由于捕捞效率高，再加上配额限制和鱼类的洄游行为，导致季节性捕捞时间相对较短，主要为：鲱鱼7 - 8月，鲭鱼1 - 2月和10 - 11月。年度捕捞配额的大幅波动，加上渔民的观察结果与评估产出之间的不匹配，导致工业界呼吁改进对这些鱼类的科学研究。作为其中的一部分，自2018年以来，该行业通过SPFA与UHI和MSS合作，制定了渔民自我抽样和渔民/科学联合抽样方案，这些方案已被苏格兰政府采纳为收集上层海洋数据的途径。这些方案收集逐运分辨率的数据，并提供以前无法获得分辨率的生物数据。数据集继续增长，并已成熟，可用于分析生物因素和与环境变量的关系。除了捕获量数据中明显的季节性和年际变化外，还有一系列外部因素影响着船长的捕捞选择，包括何时捕捞，他们的目标是鱼的大小，成熟度和状况，以及在何处捕获（苏格兰加工商或国外）。这些都受到市场力量的影响，近年来受到俄罗斯制裁（自2019年以来）和2022年乌克兰战争的严重影响。从1945年到2000年，远洋渔业的发展已被记录在案，但自2000年以来，船队进行了全面更新，技术取得了重大进步，提高了捕捞效率。此外，通过AIS和VMS引入船舶可见性使船长能够跟踪船队的位置，消除了捕鱼位置保密——这是文化的巨大变化，减少了船只寻找鱼群的时间，改变了渔民的行为将进一步提高捕捞效率，并可能通过燃料消耗减少碳足迹。该学生将与学术界和远洋工业合作。该研究将包括跨学科数据收集的一个元素，通过基于社会科学的方法，结合渔民知识的收集和分析，以及对经验数据集的分析。

Herring and mackerel are migratory species and targeted seasonally during spawning and/or feeding aggregations. These species comprise 80% by weight of the Scottish pelagic fisheries, and account for >55% by weight, and >40% by value of the entire Scottish fishing sector. The Scottish fleet is 21 large (>40-85m) modern trawlers based in Shetland, Peterhead and Fraserburgh. The fishing efficiency, combined with both restricted quotas and the migratory behaviour of the species result in relatively short seasonal fisheries that are mainly: herring July-Aug and mackerel Jan/Feb and Oct/Nov. Large fluctuations in annual fishing quota together with a mis-match between fisher observations and assessment output led to industry calls for improved science on these stocks. As part of this, the industry through the SPFA, have worked in partnership with UHI and MSS since 2018 to develop fisher self-sampling and fisher/science co-sampling programmes that have been adopted as the route through which the Scottish Government collects pelagic data [1]. These programmes collect data on a haul-by-haul resolution and are providing biological data on previously unobtainable resolution. The data-set continues to grow and is ripe for the analysis of biological factors and for correlation to environmental variables. In addition to immediately apparent seasonal and inter-annual variations within the catch data, there are a range of external factors that affect the fishing choices that skippers make in relation to when to fish, what they are targeting regarding fish size, maturity and condition, and where to land their catches (Scottish processors or abroad). These are influenced by market forces and have in recent years been significantly affected by Russian sanctions (since 2019) and in 2022 by the Ukraine war. The development of the pelagic fisheries from 1945 until 2000 has been documented [2] but since 2000 there has been a complete fleet renewal and significant technological advances that have improved fishing efficiency. Additionally, the introduction of vessel visibility through AIS and VMS has resulted in skippers being able to track where the fleet are, has eliminated fishing location secrecy - a huge change in culture, has cut the amount of time vessels spend searching for shoals and the altered fisher behaviour will have further increased catching efficiency and may have reduced carbon footprint through fuel consumption. The student will work collaboratively with both academia and the pelagic industry. The research will include an element of cross-disciplinary data collection from the incorporation of the collection and analysis of fisher knowledge, through social science-based methodologies, alongside the analysis of empirical datasets.