Census of the Diversity of Abyssal Marine Life

CeDAMar - A deep-sea project documenting species diversity of abyssal plains to increase understanding of the historical causes and ecological factors regulation biodiversity and global change.

Project Leaders:
Dr Pedro Martinez Arbizu, Deutsches Zentrum fur Marine Biodiversitatsforschung, Forschungsinstitut Senckenberg, Germany

Dr Craig Smith, Department of Oceanography, University of Hawaii, Honolulu, Hawaii, USA

Census of Diversity of Abyssal Marine Life (CeDAMar) is one of seven initial field projects of the Census of Marine Life (CoML). The goal of this project is to document actual species diversity of abyssal plans as a basis for global change research and for a better understanding of historical causes and actual ecological factors regulating biodiversity. To achieve this, CeDAMar will collect reliable data on the large-scale distribution of one of the largest and most inaccessible environments on our planet.

The Deep Unknown
The deep sea harbors vast numbers of species, most of which are still unknown. Global estimates of marine species vary between 500,000 and 10 million. Since there is no inventory of the fauna of even a single ocean basin, extrapolation of total species numbers of the global abyssal fauna is impossible or at best very speculative. The program will focus on benthic, epibenthic and hyperbenthic organisms because of their high species-richness.
The study of the deep sea offers a number of advantages. Environmental factors appear to be more homogenous in the deep sea than in many other environments and are easier to measure due to the relative uniformity of large areas. Anthropogenic effects are reduced, and communities are for the most part found in their natural state. Geological information on kinds and age of the sediments in the deep sea is available from past and ongoing projects.

Scientific Objectives
CeDAMar will develop standardized protocols for surveying marine organisms in abyssal marine sediments, including reliable collecting devices in order to avoid damage to fragile deepsea animals. The standard protocols will enable results from different ocean basins will be comparable today as well as in the future. CeDAMar will also contribute to the development and testing of new, more efficient collecting techniques.
Samples will be collected along approximately 1000 km long transects. To exclude small-scale variations which could influence biodiversity estimations, larger areas will be sampled with an epibenthic sledge and repeated box corer (or new devices with the same function) and multicorer hauls. Underwater cameras will document the morphology of the ocean bed, the effects of bioturbation and the abundance of microfauna. The collected material will be analyzed with modern systematic methods.

CeDAMar will describe in detail the species found during its expeditions and write keys in order to ensure reliable identification of specimens collected during subsequent expeditions or other teams. It is intended to describe the change in species composition along transects and to compare different ocean regions to learn more about the composition of local communities, large-scale distribution of a single species, the influence of sediment parameters and primary production on the diversity of benthic communities. Species data will also be related to the history and age of the basins, present and hypothesized past bottom currents, and paleoclimatic data. Taxonomists will study the distribution of their groups to explain the geographic and phylogenetic origin of deep-sea species. A synthesis of all data will help to better understand the history of deep-sea fauna, its present diversity and dependence on environmental parameters, such as the effects of currents, seamounts, trenches, geographic isolation and other ecological factors. Centers of high biodiversity will be identified, which will be useful for planning both commercial and conservation efforts. Finally, CeDAMar's estimation of the number of species living in the deep sea will contribute to the estimation of global species diversity.

Scientific ObjectivesClimatic change will reach the deep sea considerably later than other marine environments, but the effects of bottom temperature and the productivity of the surface waters on the environmentally sensitive fauna that live there are expected to be dramatic. CeDAMar will provide a foundation of knowledge about faunal composition, seasonal variations, and the influence of productivity in the deep sea on which any future study of the effects of global warming or human interference will have to rely. The task of CeDAMar will require an enormous scientific effort that can only be successful if all available specialists join forces in a single coordinated endeavor.

Visit the CeDAMar website.
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