RAPID: Human-Driven Trophic Cascades: Mesopredator Release and Recreational Fishing in Estuaries

RAPID：人类驱动的营养级联：中捕食者的释放和河口的休闲捕鱼

• 批准号: 2032200
• 负责人: Delbert Smee
• 金额: $ 7.87万
• 依托单位: Marine Environmental Sciences Consortium
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-05-15 至 2022-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2032200&HistoricalAwards=false
• 关键词: RAPID; Human; Driven; Trophic; Cascades

Human activity affects natural populations of organisms directly through exploitation and indirectly by changing how species interact with each other. This project is investigating the effect of fishing on an estuarine food web. In the oyster reef food chain, newly settled oysters are eaten by crabs, and the crabs are in turn eaten by fish. More fish predators mean fewer crabs and more oysters. Fish also reduce foraging by crabs, which further benefits oysters. Although small-scale experimental studies have measured the impact of fish exclusion on oyster reefs, the links between fishing, fish populations and oyster reefs require an estuary-scale experiment. Stay-at-home orders associated with the COVID-19 pandemic has curtailed fishing activity throughout estuaries. This project combines empirical experiments and fisheries monitoring data from before, during and after COVID-19-related restrictions to investigate how changes in fishing activity influence oyster reef food webs. Building on 10+ years of preexisting observations the dataset encompasses a 100-year flood, a hurricane, and now a pandemic, a rare opportunity to investigate the effects of low fishing pressure in the absence of other disturbances. The broader impacts of this study contribution of data towards optimizing management and conservation of marine resources. Oyster reefs are essential habitat that perform ecosystem services such as water filtration and shoreline stabilization, but they are also harvested as a commercial fishery. Interest in estuarine systems for recreation and fishing is high along the Gulf of Mexico. Public displays and outreach activities at the Dauphin Island Sea Lab will include results from this project to increase awareness of the effect of human activity on local ecosystems.The loss of top predators can destabilize ecosystems by making them more prone to invasions, altering nutrient fluxes within and between habitats, and impeding recovery after disturbances. Overfishing reduces the abundance of higher order predators, leading to higher abundances of intermediate consumers or mesopredators. Mesopredator release can increase predation pressure on basal trophic levels, including foundation species. In estuaries, fin fish, many of which are targeted by both commercial and recreational anglers, provide an important trophic link and their removal or experimental exclusion can trigger mesopredator release. However, the extent that fishing alters communities remains poorly understood. Estuarine systems along the Gulf of Mexico have experienced nearly continuous and widespread exploitation for over a century, and the few examples of temporary releases from fishing pressure have co-occurred with other natural disasters. The COVID-19 pandemic has curtailed fishing and has provided a unique research opportunity. Using a Before After Control Impact (BACI) design, the effects of fishing pressure on top-down control is being investigated in a model system, oyster reefs. Fishing activity and fish stock assessments are compared with field experiments to determine top predator feeding activity, mesopredator abundances, and recruitment and growth of oysters. To gauge changes in the structure of estuarine food webs, the data are being compared with 10+ years of preexisting results to isolate the effect of fishing activity from confounding factors associated with natural disasters like hurricanes and floods.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

人类活动通过开发直接影响生物体的自然种群，并通过改变物种之间的相互作用间接影响生物体的自然种群。这个项目正在调查捕鱼对河口食物网的影响。在牡蛎礁食物链中，新定居的牡蛎被螃蟹吃掉，螃蟹又被鱼吃掉。更多的鱼类捕食者意味着螃蟹更少，牡蛎更多。鱼类也减少了螃蟹的觅食，这进一步有利于牡蛎。虽然小规模的实验研究已经测量了鱼类排斥对牡蛎礁的影响，但捕鱼、鱼类种群和牡蛎礁之间的联系需要一个河口规模的实验。与COVID-19疫情相关的居家令减少了整个河口的捕鱼活动。该项目结合了COVID-19相关限制之前、期间和之后的实证实验和渔业监测数据，以调查捕鱼活动的变化如何影响牡蛎礁食物网。基于10多年的观测数据，该数据集包括100年一遇的洪水、飓风和现在的大流行病，这是一个难得的机会，可以在没有其他干扰的情况下调查低捕捞压力的影响。这项研究的更广泛影响是为优化海洋资源的管理和保护提供数据。牡蛎礁是提供水过滤和海岸线稳定等生态系统服务的重要栖息地，但它们也被作为商业渔业捕捞。 沿着墨西哥湾，人们对休闲和捕鱼的河口系统很感兴趣。海豚岛海洋实验室的公开展示和推广活动将包括该项目的成果，以提高人们对人类活动对当地生态系统影响的认识。顶级捕食者的消失会使生态系统更容易受到入侵，改变栖息地内部和之间的营养通量，阻碍干扰后的恢复，从而破坏生态系统的稳定。过度捕捞减少了高阶捕食者的丰度，导致中间消费者或中型捕食者的丰度增加。 中捕食者释放可以增加捕食压力的基础营养水平，包括基础物种。在河口，鳍鱼，其中许多都是商业和娱乐垂钓者的目标，提供了一个重要的营养链，他们的删除或实验排除可能会触发中捕食者释放。然而，人们对捕鱼改变社区的程度仍然知之甚少。 世纪以来，墨西哥湾沿着的河口系统经历了几乎持续和广泛的开发，渔业压力暂时释放的少数例子与其他自然灾害同时发生。COVID-19大流行减少了渔业，并提供了一个独特的研究机会。使用前后控制影响（BACI）设计，捕捞压力对自上而下的控制的影响正在研究中的模型系统，牡蛎礁。渔业活动和鱼类资源的评估进行了比较，实地实验，以确定顶级捕食者的摄食活动，mesopredator丰度，招聘和牡蛎的生长。为了衡量河口食物网结构的变化，将这些数据与10多年来已有的结果进行比较，以将渔业活动的影响与飓风和洪水等自然灾害相关的混杂因素隔离开来。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。