Fish nurseries in a changing world: towards functional indicators of habitat quality

科学背景确定和保护“基本鱼类栖息地”正在成为一项研究、管理和政策优先事项。保护每个生命阶段所需的栖息地对于创建可持续渔业和养护受威胁物种是必要的，但对鱼类栖息地需求的了解非常有限，特别是对幼鱼。青少年往往严重依赖受人类活动严重影响的浅海近海地区。人们对这些年轻阶段知之甚少，因为它们很少成为商业渔业或独立于渔业的调查的目标。目前，幼鱼栖息地的质量通常是简单地根据它们所含鱼类的丰富程度来评估的。鱼类生长、存活和进入成年种群等功能指标往往被忽视，但对于量化不同区域作为鱼类苗圃的重要性至关重要。方法这个博士项目包括1)实验室实验，以开发自由放养的幼鱼摄食、生长和移动的新的分子和地球化学指标；2)在塞文河口进行广泛的实地工作，将这些工具应用于现实生活环境，并确定具有商业价值的物种--普通比目鱼--的关键栖息地需求。培训学生将在一系列技能方面接受培训，以监督者在以下方面的核心专业知识为基础：分子生长指数、用于食物特征的DNA元生物编码以及用于营养和连通性重建的生物地球化学示踪剂：这些关键技术不仅与渔业有关，而且广泛涉及环境研究学科。咨询公司‘海洋生态’(CASE合作伙伴)以及德文郡和塞文郡近岸渔业和保护局(合作合作伙伴)为采样具有挑战性的河口环境提供了一个独特的平台，并提供了应用创新研究支持海洋政策和管理决策的经验。

Scientific Background The identification and conservation of "Essential Fish Habitat" is emerging as a research, management and policy priority. Protecting habitats required for every life-stage is necessary to create sustainable fisheries and conserve threatened species, but knowledge of fish habitat needs is very limited, particularly for juveniles. Juveniles are often critically dependent on shallow, inshore areas which are heavily impacted by human activities. Little is known about these young stages because they are rarely targeted by commercial fisheries or fisheries-independent surveys. Currently, juvenile habitat quality is typically assessed simply on the basis of the abundance of fish they contain. Functional indicators such as fish growth, survival and movement into the adult population are often overlooked, but are essential to quantifying the importance of different areas as fish nurseries. Methodology This PhD project involves 1) laboratory experiments to develop novel molecular and geochemical indices of feeding, growth and movement in free-ranging juvenile fish; and 2) extensive field work in the Severn Estuary to apply these tools in a real-life setting and identify key habitat needs of a commercially valuable species, the common sole Solea solea. Training The student will be trained in a range of skills, building on core expertise of the supervisors in molecular growth indices, DNA metabarcoding for diet characterisation, and biogeochemical tracers for trophic and connectivity reconstruction: key techniques relevant not just for fisheries, but broadly across environmental research disciplines. The consultancy 'Ocean Ecology' (CASE partner) and the Devon and Severn Inshore Fisheries and Conservation Authority (collaborative partner) offer a unique platform for sampling challenging estuarine environments and experience in applying innovative research to support marine policy and management decisions.