Ocean Acidification-Category 1- Impact of ocean acidification on survival of early life stages of planktonic copepods in the genus Calanus in the northern

海洋酸化-类别1-海洋酸化对北部哲水蚤属浮游桡足类早期生命阶段生存的影响

• 批准号: 1041081
• 负责人: Jeffrey Runge
• 金额: $ 69.77万
• 依托单位: University of Maine
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-11-01 至 2014-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1041081&HistoricalAwards=false
• 关键词: Ocean; Acidification; Category; Impact; ocean

While attention concerning impacts of predicted acidification of the world's oceans has focused on calcifying organisms, non-calcifying plankton may also be vulnerable. In this project, the investigator will evaluate the potential for impacts of ocean acidification on the reproductive success of three species of planktonic copepods in the genus Calanus that are prominent in high latitude oceans. C. finmarchicus dominates the mesozooplankton biomass across much of the coastal and deep North Atlantic Ocean. C. glacialis and the larger C. hyperboreus are among the most abundant planktonic copepods in the Arctic Ocean. Previous research showed that hatching success of C. finmarchicus eggs was severely inhibited by increased CO2 and lower pH in seawater, but only tested at an extreme level. Preliminary results in the investigator's laboratory indicate that hatching success of C. finmarchicus is substantially reduced at increased seawater CO2 concentrations corresponding to pH levels between 7.9 and 7.5. Predictions of likely decline of surface pH levels to 7.7-7.8 over the next century raise questions about impacts on Calanus population dynamics if these preliminary results are confirmed. C. finmarchicus, for example, is presently at the southern edge of its range in the Gulf of Maine. The combination of higher surface layer temperature and lower pH may inhibit reproductive success during the late summer/fall bloom, which the PI hypothesize is critical to sustain the overwintering stock in this region. The investigators will collect C. finmarchicus females from the Gulf of Maine and, with the assistance of Canadian colleagues, C. glacialis and C. hyperboreus females from the deep lower St. Lawrence Estuary. They will conduct laboratory experiments in which hatching success, development and growth of Calanus nauplius stages are measured in controls of natural seawater and at a series of treatments in which CO2 concentrations, pH and temperature are rigorously controlled to represent possible future states of the northern ocean. The investigators will measure present surface and deep pCO2 and pH across the Gulf of Maine, including its deep basins, during a research cruise. The study will evaluate the hypothesis that predicted levels of CO2 increase in the northern ocean will impact population dynamics of the Calanus species. Using the results from the research cruise and a recently developed 1-D, Individual-Based life cycle model, the PI will explore in detail scenarios of impact of higher temperature and lower surface and deep pH on population dynamics of C. finmarchicus in the Gulf of Maine.Broader impacts: The lipid-rich Calanus species are considered key intermediary links between primary production and higher trophic levels in North Atlantic and Arctic Ocean food webs. Impacts of higher surface temperature and lower pH on reproductive success may potentially lead to profound changes in energy transfer and structure of pelagic ecosystems in the northern oceans. In the Gulf of Maine, C. finmarchicus serves as primary prey for herring, sand lance, and mackerel, as well as the endangered northern right whale, warranting thorough evaluation of ocean acidification effects on its population dynamics. This research will provide cross discipline training to a graduate student and undergraduate student interns. Data will be deposited in a recognized data archiving center and results disseminated through presentations at scientific meetings and peer reviewed research articles. Public outreach will be planned as part of the Gulf of Maine Research Institute community activities, including learning opportunities associated with the Cohen Center for Interactive Learning directed at fifth and sixth graders in the state of Maine.

虽然人们对世界海洋预测酸化影响的关注主要集中在钙化生物上，但非钙化浮游生物也可能很脆弱。在该项目中，研究人员将评估海洋酸化对高纬度海洋中常见的哲水属三种浮游桡足类动物繁殖成功率的潜在影响。 C. finmarchicus 在大部分沿海和北大西洋深处的中型浮游生物生物量中占主导地位。 C. glacialis 和体型较大的 C. hyperboreus 是北冰洋最丰富的浮游桡足类动物。先前的研究表明，海水中二氧化碳含量增加和 pH 值降低严重抑制了 C. finmarchicus 卵的孵化成功，但仅在极端水平下进行了测试。研究者实验室的初步结果表明，当海水二氧化碳浓度增加（相当于 7.9 至 7.5 之间的 pH 值）时，C. finmarchicus 的孵化成功率会大大降低。预测下个世纪地表 pH 值可能下降至 7.7-7.8，如果这些初步结果得到证实，就会引发对哲水蚤种群动态影响的疑问。例如，C. finmarchicus 目前位于缅因湾其分布范围的南端。较高的表层温度和较低的 pH 值的结合可能会抑制夏末/秋季开花期间的繁殖成功，PI 假设对于维持该地区的越冬种群至关重要。研究人员将从缅因湾收集雌性 C. finmarchicus，并在加拿大同事的协助下，从圣劳伦斯河口下游深处收集 C. glacialis 和 C. hyperboreus 雌性。他们将进行实验室实验，在控制天然海水和严格控制二氧化碳浓度、pH 和温度的一系列处理中测量哲水蚤无节幼体阶段的孵化成功、发育和生长，以代表北大洋未来可能的状态。研究人员将在一次研究航行中测量缅因湾（包括其深海盆地）目前的表面和深层 pCO2 和 pH 值。该研究将评估以下假设：预测北部海洋二氧化碳浓度增加将影响哲水蚤物种的种群动态。利用研究巡航的结果和最近开发的一维、基于个体的生命周期模型，项目负责人将详细探索较高温度、较低表面和深层 pH 值对海湾 C. finmarchicus 种群动态的影响的详细情景更广泛的影响：富含脂质的哲水藻物种被认为是北大西洋和北冰洋食物网初级生产和较高营养水平之间的关键中介联系。较高的表面温度和较低的 pH 值对繁殖成功的影响可能会导致北部海洋中上层生态系统的能量转移和结构发生深刻变化。在缅因湾，C. finmarchicus 是鲱鱼、沙矛鱼和鲭鱼以及濒临灭绝的北露脊鲸的主要猎物，因此需要彻底评估海洋酸化对其种群动态的影响。这项研究将为研究生和本科生实习生提供跨学科培训。数据将存放在公认的数据存档中心，并通过在科学会议上的演示和同行评审的研究文章来传播结果。公共宣传活动将作为缅因湾研究所社区活动的一部分进行规划，包括与科恩互动学习中心相关的学习机会，为缅因州的五年级和六年级学生提供学习机会。