Drivers of ocean acidification in a temperate urbanized estuary undergoing nutrient loading reductions

大约三分之一的人类产生的二氧化碳(CO2)已经溶解在海洋中，显著减缓了气候变化和全球变暖。然而，随着更多的二氧化碳溶解在海洋中，海水变得酸化，因为二氧化碳是一种弱酸。我们称这种变化为海洋酸化(OA)。海洋酸化对海洋生物有重大和持久的影响，因为酸化的水会导致许多海洋生物的贝壳溶解。美国社会已经在努力应对办公自动化的不利影响。预计到2100年，OA将给美国贝类行业带来每年4亿美元的经济损失。因此，迫切需要了解海洋生态系统正在发生怎样的变化，以及在沿海水域管理它的潜在方法。目前，无论是大范围还是小范围的办公自动化变化，我们都没有很好的理解，因为有太多相互竞争的过程影响着办公自动化。影响海洋酸化的最戏剧性的过程之一是由于人类的输入而从河流中额外增加的营养物质负荷。虽然适度的营养水平对于海洋生物的生存是必要的，但营养水平过高会导致海洋浮游生物大量繁殖。当浮游生物死亡时，它们会沉入海底，在那里被细菌分解，加速贝类生活的环境。近几十年来，管理机构一直致力于通过减少向沿海水域输入的营养物质来改善水质，这有可能减少营养盐输入，尽管海洋营养输入并非最初的动机。据我们所知，目前还没有有针对性的研究来了解OA如何应对激进的营养减少。纳拉甘西特湾是美国变暖最快的河口之一，近几十年来，由于故意减少营养物质，纳拉甘西特湾的平均营养输入减少了三分之一以上。因此，纳拉甘西特湾可以被认为是一个天然的实验室，可以帮助更好地了解其他沿海地区可能很快就会经历的环境管理行动和气候变化所造成的办公自动化变化。该项目将利用现有的水质监测网络，收集新的数据，并利用沿海生物地球化学模型来量化在RI纳拉甘西特湾的OA变化及其驱动机制。通过与公众和当地贝类养殖者的接触，我们将提高他们对OA的认识，并加强他们在短期和长期进行正在进行的或新的水产养殖作业的能力。随着美国越来越多的州减少营养物质投入以改善沿海水质，该项目将允许全国范围内的管理机构进行下一代改进，以最大限度地限制面对气候变化的可持续渔业和野生动物的开放程度。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

About one-third of human-produced carbon dioxide (CO2) has dissolved in the ocean, significantly slowing down climate change and global warming. However, as more CO2 dissolves in the sea, the ocean water becomes acidified because CO2 is a weak acid. We call this change ocean acidification (OA). OA has a significant and lasting impact on marine life, as acidified water causes shell dissolution for numerous marine species. US society is already grappling with the adverse effects of OA. OA is predicted to lead to economic losses of $400 million annually by 2100 for the US shellfish industry. Therefore, it is urgent to understand how OA is changing and the potential approaches to managing it in coastal waters. Presently, we do not have a good understanding of OA change at either the large or the small scale because so many competing processes impact OA. One of the most dramatic processes that affect ocean acidification (OA) is the extra nutrient loading from rivers due to human inputs. While moderate nutrient levels are necessary to support marine life, nutrient levels that are too high can cause oceanic plankton blooms. As plankton die, they sink to the seafloor, where they are decomposed by bacteria and speed up OA where shellfish live. In recent decades, management agencies have been working on improving water quality by reducing the nutrient input to coastal waters, which has the potential to reduce the OA even though OA is not the initial motivation. To our knowledge, there has yet to be targeted research to understand how OA responds to aggressive nutrient reduction. The average nutrient input to Narragansett Bay– one of the most rapidly warming estuaries in the US–has been reduced over one-third in recent decades because of intentional nutrient reduction. Therefore, Narragansett Bay can be considered a natural laboratory that can help in better understanding the OA change that other coastal areas may soon experience resulting from environmental management actions and climate change. This project will leverage the existing water quality monitoring network, collect new data, and utilize a coastal biogeochemical model to quantify OA change and the mechanisms driving its change in Narragansett Bay, RI. Through engagement with the public and local shellfish growers, we will increase their awareness of OA and enhance their ability to carry out ongoing or new aquaculture operations in the near and long term. As more US states reduce nutrient input to improve coastal water quality, this project will allow management agencies nationwide to make next-generation refinements to best limit OA for sustainable fisheries and wildlife in the face of climate change.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.