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

沉淀物覆盖的深海海底可以说是地球上最大的栖息地。尽管存在极端条件，但某些分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(例如热带雨林中的昆虫)中物种最丰富的群体相媲美。这种财富的性质是有争议的。一些研究报告称，少数物种的活动范围在100‘S到1000’S之间，但许多物种只在一个地点发现。在另一项工作中，据报道有更多的物种有很大的活动范围。更糟糕的是，现有的数据可能并不完全提供信息，因为关于将个体分配给物种的决定是基于形态做出的，这可能无法区分哪些物种在生物学上是独立的，也就是通常所说的神秘物种。深海沉积物中的物种范围有多大的问题需要解决，因为这对深海沉积物生态的概念模型具有深远的意义。如果大多数物种的活动范围都很小，深海的学生就会想要了解，例如，在一个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，如果大多数物种都有很大的活动范围，研究人员将希望研究与百米S至一千米S物种的遗传连通性有关的问题。该项目的主要目标是评估一些以沉积物为栖息地的深海物种拥有大范围活动范围的可能性。为此，这些调查人员将在美国西海岸外大陆坡的四个纬度(47.6°N、42.6°N、36.5°N和32.6°N)的每个纬度分别从2700米和3700米深的一个站点采集沉积物样本。这项研究的目标群体将是非常常见的鳍足类桡足动物。每个样本中的每个成年竖琴将根据传统的形态特征被归类到一个物种。然后，这些成年的竖琴形桡足类动物将被切成两半；后部将用于DNA序列分析，而前部将被保留作为凭证样本。DNA序列分析将被用来确定根据形态被认为是同一物种的个体是否基于分子数据形成一个得到良好支持的物种群。这些物种群在不同站点之间的分布将使调查人员知道，它们的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澄清物种范围和人类干扰之间的关系来帮助政策制定者评估深海海底人类干扰(例如海洋倾倒)的环境成本，从而使社会受益。调查人员还将通过在科学会议和出版物上的陈述与同事分享他们的成果，并通过公开讲座和网站向更广泛的受众分享他们的成果。该项目还将促进代表性不足的群体参与海洋学。

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.