Do sediment-dwelling species have large ranges along a continental slope?

栖息在沉积物中的物种是否沿着大陆坡有很大的活动范围？

• 批准号: 0727243
• 负责人: David Thistle
• 金额: $ 58.93万
• 依托单位: Florida State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-08-01 至 2013-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0727243&HistoricalAwards=false
• 关键词: Do; sediment; dwelling; species; large

The sediment-covered deep-sea floor is arguably the largest habitat on Earth. Despite the extreme conditions, the number of species present at a given location for some taxa can rival that of the most species-rich groups in the most species-rich habitats on Earth (e.g., insects in rain forests). The nature of this richness is controversial. Some studies have reported that a few species had ranges of 100's to 1,000's of kilometers, but many species were found at only a single location. In other work, many more species were reported to have large ranges. Worse, the existing data may not be completely informative because the decisions about the assignment of individuals to species were made on the basis of morphology, which can fail to distinguish species that are biologically separate, and commonly known as cryptic species. The question of how big is a species range in deep-sea sediments needs to be resolved because it matters profoundly to conceptual models of the ecology of deep-sea sediments. If most species have small ranges, students of the deep sea will want to understand, for example, how species' ranges are bounded in an environment that appears to have few physical barriers. Alternatively, if most species have large ranges, investigators will want to study issues related to the genetic connectivity of species over 100's to 1,000's of kilometers. The primary objective of this project is to evaluate the possibility that some sediment-dwelling deep-sea species have large ranges. To do that these investigators will collect sediment samples from one station at 2,700 m and one at 3,700 m depth at each of four latitudes (47.6° N, 42.6° N, 36.5° N, and 32.6° N) on the continental slope off the west coast of the United States. The very common harpacticoid copepods will be the target group for this study. Each adult harpacticoid from each sample will be assigned to a species on the basis of traditional morphological characters. Each of these adult harpacticoid copepods will then be cut in two; the posterior portion will be used for DNA-sequence analysis, and the anterior will be retained as a voucher sample. The DNA-sequence analysis will be used to determine whether the individuals deemed to be the same species on the basis of morphology form a well-supported species group based on molecular data. The distribution of these species groups among stations will allow the investigators to know that its range is at least as large as the distance between the stations where they were found. The proposed research could benefit society by helping policy makers evaluate the environmental cost of human disturbance of the deep-sea floor (e.g., ocean dumpingl) by beginning to clarify the relationship between species ranges and human disturbances. The investigators will also share their results with colleagues through presentations at scientific meetings and in publications and to a wider audience by means of public lectures and a web site. The project will also foster the participation of underrepresented groups in oceanography.

沉积物覆盖的深海海底可以说是地球上最大的栖息地。尽管条件极端，但某些类群在特定地点的物种数量可以与地球上物种最丰富的栖息地中物种最丰富的群体（例如雨林中的昆虫）相媲美。 这种丰富性的本质是有争议的。 一些研究报告称，一些物种的活动范围可达数百至数千公里，但许多物种仅在一个地点被发现。 在其他工作中，据报道还有更多物种具有较大的分布范围。 更糟糕的是，现有数据可能并不完全提供信息，因为将个体分配给物种的决定是根据形态学做出的，这可能无法区分生物学上独立的物种，通常称为神秘物种。 深海沉积物中的物种范围有多大的问题需要解决，因为它对深海沉积物生态的概念模型至关重要。 例如，如果大多数物种的活动范围较小，那么深海研究人员就会想要了解，在似乎几乎没有物理障碍的环境中，物种的活动范围是如何受到限制的。 或者，如果大多数物种的分布范围很大，研究人员将希望研究与超过 100 到 1,000 公里的物种的遗传连通性相关的问题。 该项目的主要目标是评估一些沉积物栖息的深海物种具有大范围的可能性。 为此，这些调查人员将从美国西海岸大陆坡四个纬度（北纬 47.6°、北纬 42.6°、北纬 36.5° 和北纬 32.6°）各 2,700 m 深度的一个站和 3,700 m 深度的一个站收集沉积物样本。 非常常见的类桡足类动物将是本研究的目标群体。 每个样本中的每个成虫将根据传统形态特征被分配到一个物种。 然后，这些成年桡足类桡足类动物将被切成两半；后部将用于 DNA 序列分析，前部将保留作为凭证样本。 DNA序列分析将用于确定根据形态学被视为同一物种的个体是否形成基于分子数据的得到充分支持的物种组。 这些物种组在站点之间的分布将使调查人员知道其范围至少与发现它们的站点之间的距离一样大。 拟议的研究可以通过开始阐明物种范围与人类干扰之间的关系，帮助政策制定者评估人类干扰深海海底（例如海洋倾倒）的环境成本，从而造福社会。 研究人员还将通过在科学会议和出版物上的演讲与同事分享他们的结果，并通过公开讲座和网站向更广泛的受众分享他们的结果。 该项目还将促进代表性不足的群体参与海洋学。