The implications of spatial and temporal variation in marine biodiversity of demersal species for community ecology, marine policy and the Scottish fi

在北海，已确定了底层鱼类、表层底栖无脊椎动物和底栖动物的生物多样性空间格局。就鱼类群落而言，物种丰富度在北海北方和苏格兰沃茨达到高峰（Reiss等人，2010年）。在大西洋主要流入水域附近，鱼类的多样性似乎很高（Rogers等人，1995年）。相比之下，生物多样性的时间趋势在很大程度上是未知的。对生物多样性时间趋势的任何调查都必须考虑到强烈的空间梯度。抛弃是指在捕鱼过程中将非目标鱼或尺寸过小的鱼放回大海。在北海，鱼类群落的高度生物多样性可能导致大量丢弃商业和非商业物种。从2019年起，苏格兰和其他欧洲渔船不能丢弃通过设定总允许渔获量管理的商业物种的不需要的渔获物，即，额度因此，渔业是强烈的激励，以避免不必要的商业物种，通过更好的战术决策，何时何地fish.Spatial模式的捕鱼和丢弃没有调查的生物多样性的时空趋势。具有一贯高多样性特点的地点可能会有更大的丢弃潜力，特别是在商业物种也很丰富和捕鱼活动很高的地方。渔业的过度开发对生物多样性产生了负面影响（Greenstreet & Hall 1996;科尔等人，2016），导致鱼类群落结构随时间发生变化。为了帮助渔业了解生物多样性的空间结构及其对生物多样性的影响，必须调查商业和非商业鱼类群落的时空生物多样性。然后可以使用这些知识，结合影响海上丢弃的其他因素，来描述我们在这里所说的丢弃潜力的空间变化。本博士项目的目标1是利用物种丰富度（R）作为生物多样性的替代指标来估计鱼类群落的生物多样性。R将根据国际海洋考察理事会公开提供的科学调查数据进行估算。将确定R的时空变异性，以评估北海内是否有一致的生物多样性“热点”或随时间的方向性趋势。目标2将开发新的指标，估计丢弃潜力的北海与最终目标，使这些指标相关的战术决策何时何地捕鱼。这一指标将根据苏格兰海洋科学公司对丢弃的独立估计进行测试。然后，将丢弃潜力的空间解析表示与描述实际丢弃的数据进行比较，这些数据来自海洋苏格兰-科学，他们是本项目的共同主管。培训预算还将用于渔业数据使用方面的专门培训，例如海考会在哥本哈根提供的课程。该项目在生态学、渔业科学和政策的界面上提供了非常有趣的研究。鉴于生物多样性是界定良好环境状况的定性描述之一，该项目有可能为《海洋战略框架指令》的交付提供信息。该项目将与渔业进行联络，特别是在评估其对空间和时间信息的需求方面。

In the North Sea, spatial patterns in biodiversity have been identified for demersal fish, epibenthic invertebrates and infauna. For the fish community, species richness exhibits peaks the northern North Sea and in Scottish waters (Reiss et al. 2010). Diversity of fish appears high near major inflows of Atlantic water (Rogers et al. 1995). By contrast, temporal trends in biodiversity are largely unknown. Any investigation of temporal trends in biodiversity must account for strong spatial gradients. Discarding is the term used where non-target or undersized fish are returned to the sea during fishing. In the North Sea, the high biodiversity of the fish community can lead to substantial discarding of both commercial and non-commercial species. From 2019 onwards, Scottish and other European fishing vessels are unable to discard unwanted catch of commercial species that are managed through setting of total allowable catches, i.e., quotas. The fishing industry is therefore strongly incentivised to avoid unwanted commercial species through better tactical decision making about when and where to fish.Spatial patterns in fishing and discarding has not been investigated in relation to spatio-temporal trends in biodiversity. Locations that are characterised by consistently high diversity could be expected to have greater potential for discarding, particularly where commercial species are also abundant and fishing activity is high. Overexploitation by fisheries negatively affects biodiversity (Greenstreet & Hall 1996; Coll et al. 2016), leading to changes in fish community structure over time. To aid the fishing industry in understanding spatial structure in the biodiversity as well as their impact on biodiversity, it is imperative to investigate spatio-temporal biodiversity in both the commercial and non-commercial fish community. This knowledge can then be used, in combination with other factors that impact discarding at sea, to describe spatial variation in what we refer to here as discard potential. Project descriptionAim 1 of this PhD project is to estimate biodiversity of the fish community using species richness (R) as a proxy for biodiversity. R will be estimated from scientific survey data that are publicly available from the International Council for the Exploration of the Seas (ICES). Spatio-temporal variability in R will be determined so as to evaluate whether there are consistent 'hotspots' of biodiversity or directional trends over time within the North Sea. Aim 2 will develop novel metrics for estimating discard potential for the North Sea with the ultimate aim of making these metrics relevant to the tactical decision making about when and where to fish. This metric will be tested against independent estimates of discarding from Marine Scotland - Science. Spatially resolved representations of discard potential will then be compared to data describing actual discarding that available from Marine Scotland - Science who are co-supervisors of this project.Skills developmentTraining in the statistical analysis of spatio-temporal fisheries data will be a central part of training. The training budget will also allow for specialised training in the use of fisheries data, for example the courses offered by ICES in Copenhagen. BenefitsThis project offers highly interesting research at the interface of ecology, fisheries science and policy. There is potential for the project to inform delivery of the Marine Strategy Framework Directive given that biodiversity is one of the qualitative descriptors defining Good Environmental Status. The project will liaise with the fishing industry, particularly in assessing their needs for spatial and temporal information.