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

From proposal abstract:

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.