RUI: Dissolution Mortality of Juvenile Bivalves in Coastal Marine Deposits.

RUI：沿海海洋沉积物中幼年双壳类的溶解死亡率。

• 批准号: 0622999
• 负责人: Mark Green
• 金额: --
• 依托单位: Saint Joseph's College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-11-01 至 2010-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0622999&HistoricalAwards=false
• 关键词: RUI; Dissolution; Mortality; Juvenile; Bivalves

ABSTRACTProposal # OCE-0622999Despite major advances towards understanding the factors controlling invertebrate recruitment to benthic communities, many questions remain regarding causes of the extreme juvenile mortality of post-larval bivalves. It is now widely recognized that carbonate undersaturation is a common feature in temperate, coastal, organic-rich surface sediments that are dominated by deposit feeding benthos where many organisms have calcium carbonate shells. Such undersaturation may make it difficult for recently settled, juvenile bivalves to form their shell, and so shell dissolution could represent a significant source of mortality for juvenile bivalves. If true, there would be important implications for benthic community recruitment, survivorship, and the coupling between early diagenetic processes and benthic community form and function. In this research, a PI from St. Joseph's College will conduct a multi-faceted study that will: (1) determine the effect of carbonate saturation state at the sediment-water interface on recruitment and survivorship of juvenile bivalves following their transition from pediveligers to new juveniles in intertidal mud, (2) evaluate the chemical (reaction) and biotic (transport) processes that control saturation state in these same muds and, (3) develop coupled stage-based/diagenetic models of juvenile bivalve shell dissolution mortality under "scenarios" of carbonate saturation due to variability in the carbonate cycle. Studies will be conducted on the commercially valuable species Mya arenaria and Mercenaria mercenaria. Fieldwork will be conducted at two sites in Casco Bay, Gulf of Maine, that differ in their biological and diagenetic characteristics, yet both have substantial sets of Mercenaria and Mya. The field research will focus on cohort monitoring of Mya and Mercenaria and the effect of carbonate mineral saturation state on the variability in juvenile abundance. "Sediment buffering" experiments will be used to discern if CaCO3 buffering of surface sediments immediately following the set prevents undersaturation by limiting external shell dissolution of juveniles. The site comparisons will permit examination of the importance of dissolution mortality as a function of both the biotic and diagenetic setting. Sampling at low water and mid-upper intertidal heights within each site will examine variability in dissolution mortality as a function of tidal exposure. Laboratory experiments will artificially regulate surface sediment saturation state, and thus juvenile bivalve habitat, while maintaining supersaturated conditions in the overlying water. Dissolution mortality experiments will determine "threshold" saturation states below which external shell dissolution mortality occurs for specific size classes of Mercenaria and Mya (2.0 mm). Additional laboratory experiments will determine the immediate response of bivalves to sediment surfaces of different saturation states using a combination of direct observations and flume experiments. The collective results from the field and laboratory will be used to model scenarios of dissolution mortality in both species due to anthropogenic and natural changes in carbonate cycling.Broader impacts of this study include both an extremely strong educational component and important societal benefits. Saint Joseph's College of Maine is an undergraduate institution with about 70% of women in the student body. The immersion of students into research will build on the PI's prior CAREER award and promote students attending and/or presenting research results at national/international conferences contributing as coauthors on manuscripts. Improved understanding of juvenile bivalve mortality could have important impact on management of coastal fisheries. Finally, this research would place coastal populations of juvenile bivalves into context with open ocean plankton with carbonate shells and corals that are currently expected to suffer from similar problems with shell formation and subsequent mortality.

Abstract Propopals＃OCE-0622999DITE，尽管有重大进步，以理解控制无脊椎动物招募到底栖群落的因素，但关于大型后双壳类动物极端幼年死亡的原因仍然存在许多问题。 现在，人们广泛认识到，碳酸盐不饱和是温带，沿海，富含有机有机的表面沉积物的共同特征，这些特征由许多生物具有碳酸钙壳的沉积物喂养底栖生物所主导。这种不饱和可能使最近定居的幼体双壳类很难形成壳，因此壳溶解可以代表少年双壳类的重要死亡率。 如果是真的，那么对底栖界社区的招聘，生存以及早期成岩生物过程与底栖族社区形式和功能之间的耦合将会有重要影响。 在这项研究中，圣约瑟夫学院的PI将进行一项多方面的研究，该研究将：（1）确定碳酸盐饱和状态在沉积物 - 水界面上对少年双壳类的招募和生存的影响潮间泥中的新少年（2）评估在这些相同泥浆中控制饱和状态的化学（反应）和生物（运输）过程，以及（3）在少年双壳壳溶解死亡率的基于偶联的阶段/成岩模型中“由于碳酸盐周期变异性而导致的碳酸盐饱和度。将对商业有价值的物种Mya Arenaria和Mercenaria Mercenaria进行研究。 实地调查将在缅因州海湾的卡斯科湾的两个地点进行，它们的生物和成岩特征不同，但两者都有大量的Mercenaria和Mya。 现场研究将着重于对Mya和Mercenaria的队列监测以及碳酸盐矿物质饱和状态对少年丰度变化的影响。 “沉积物缓冲”实验将用于辨别集合后表面沉积物的CACO3缓冲是否通过限制少年的外壳溶解来防止饱和度。 该部位的比较将允许研究溶解死亡率的重要性，这是生物和成岩环境的函数。在每个站点内的低水和中潮间潮间高的高度上进行采样将检查溶解死亡率的可变性，这是潮汐暴露的函数。实验室实验将人为地调节表面沉积物饱和状态，从而使幼年双壳类栖息地，同时维持上层水中的过饱和条件。 溶解死亡率实验将确定“阈值”饱和状态，以下是特定尺寸的Mercenaria和Mya（2.0 mm）发生外壳溶解死亡率的情况。 其他实验室实验将通过直接观测和水槽实验的组合确定双壳类对不同饱和态的沉积物表面的立即反应。由于人为和自然的变化，碳酸盐循环的人为和自然变化，该研究的集体结果将用于对两种物种溶解死亡率的情景进行建模。这项研究的影响者的影响包括非常强大的教育成分和重要的社会利益。 缅因州圣约瑟夫学院是一家本科机构，有大约70％的学生妇女。将学生浸入研究中将基于PI先前的职业奖，并促进参加和/或在国家/国际会议上呈现研究成果的学生，作为手稿合着者。 对少年双壳类死亡率的了解可以对沿海渔业的管理产生重要影响。 最后，这项研究将使少年双壳类的沿海种群与开阔的海洋浮游生物一起，并带有碳酸盐壳和珊瑚，目前有望遭受类似的壳形成和随后死亡率的问题。