Table of Contents

• Dataset Description
  • Methods & Sampling
  • Data Processing Description
• Data Files
• Parameters
• Instruments
• Deployments
• Project Information
• Program Information
• Funding

The mesozooplankton community, with special emphasis on calanoid copepods, was studied with respect to its species composition, abundance, vertical distribution and developmental structure during the Ice Station POLarstern(ISPOL) expedition to the ice-covered western Weddell Sea. Stratified zooplankton tows were carried out nine times between 1 December 2004 and 2 January 2005 with a multiple opening/closing net between 0 and 1000 m depth. Copepods were by far the most abundant taxon, contributing more than 94% of the total mesozooplankton. ... Calanoides acutus and Metridia gerlachei represented other abundant calanoid species contributing an average of 8% and 7%, respectively. All other species comprised less than 3%. ... The Ice Station POLarstern(ISPOL) expedition provided the opportunity to continue the investigations on zooplankton in the western Weddell Sea but in a different season, in spring 2004. The aims of the present study were the analyses of the zooplankton communities under perennial sea ice cover in the western Weddell Sea during the transition from spring to early summer with emphasis on major differences in abundance, vertical distribution and stage composition of the three dominating calanoid copepods Microcalanus pygmaeus, C. acutus and Metridia gerlachei." (http://dx.doi.org/10.1016/j.dsr2.2007.12.013)

"Zooplankton was sampled between 1 December 2004 and 2 January 2005. Sampling was carried out nine times, and the interval between sampling varied between 3 and 5 days depending on the sea-ice conditions A multiple opening/closing net system (0.25 m2 aperture) equipped with five nets of 100 micron mesh size was used. Daytime vertical hauls were conducted at 0.5 m/sec between 1000 m and the surface, covering five standard depth intervals. The filtered volume was measured for each net by a digital flow meter. The samples were preserved in 4% borax-buffered formaldehyde/seawater solution and analysed for taxa composition, abundance, distribution and age structure."(http://dx.doi.org/10.1016/j.dsr2.2007.12.013)

"According to density, samples were split into subsamples (1/2 - 1/32) using a Folsom splitter. Rare taxa and developmental stages were counted from the entire sample. With 10 exceptions, calanoid and harpacticoid copepods were identified to species level, and the sex and developmental stage was also determined. Cyclopoid specimens were only identified to genus level. In the calanoid genera Paraeuchaeta, Scaphocalanus and Lucicutia and the harpactidoid Drescheriella, copepodite stages were not further identified to species level but combined. Mean abundance is given as geometric mean. The mean population stage was calculated according to Marin (1987), and the weighted mean depth after Bollens and Frost (1989). Female copepods of C. acutus and M. gerlachei were sorted from preserved samples, and four different gonad developmental stages were determined according to Runge (1985): immature (stage 1), medium ripe (stage 2), semi-ripe (stage 3) and ripe (stage 4)." (http://dx.doi.org/10.1016/j.dsr2.2007.12.013)

References:

Bollens, S.M. and B.W. Frost, 1989. Predator-induced diel vertical migration in a planktonic copepod, Journal of Plankton Research 11 (5) (1989), pp. 1047 - 1065.

Marin,V. 1987. The oceanographic structure of the eastern Scotia Sea IV. Distribution of copepod species in relation to hydrography in 1981, Deep-Sea Research I 34 (1) (1987), pp. 105 - 121.

Runge,J.A., 1985. Relationship of egg production of Calanus pacificus to seasonal changes in phytoplankton availability in Puget Sound, Washington, Limnology and Oceanography 30 (2) (1985), pp. 382 - 396.

The Census of Marine Zooplankton (CMarZ) is a field project of the Census of Marine Life (see www.CoML.org). CMarZ is working toward a taxonomically comprehensive assessment of biodiversity of animal plankton throughout the world ocean. The project goal is to produce accurate and complete information on zooplankton species diversity, biomass, biogeographical distribution, genetic diversity, and community structure by 2010. Our taxonomic focus is the animals that drift with ocean currents throughout their lives (i.e., the holozooplankton, Fig. 1). This assemblage currently includes ~6,800 described species in fifteen phyla; our expectation is that at least that many new species will be discovered as a result of our efforts. The census encompasses unique marine environments and those likely to be inhabited by endemic and undescribed zooplankton species.

The Census of Marine Life is a global network of researchers in more than 80 nations engaged in a 10-year scientific initiative to assess and explain the diversity, distribution, and abundance of life in the oceans. The world's first comprehensive Census of Marine Life - past, present, and future - will be released in 2010.

The stated purpose of the Census of Marine Life is to assess and explain the diversity, distribution, and abundance of marine life. Each plays an important role in what is known, unknown, and may never be known about what lives in the global ocean.

First, diversity. The Census aims to make for the first time a comprehensive global list of all forms of life in the sea. No such unified list yet exists. Census scientists estimate that about 230,000 species of marine animals have been described and reside in jars in collections in museums of natural history and other repositories. Since the Census began in 2000, researchers have added more than 5600 species to the lists. They aim to add many thousands more by 2010. The database of the Census already includes records for more than 16 million records, old and new. By 2010, the goal is to have all the old and the new species in an on-line encyclopedia with a webpage for every species. In addition, we will estimate how many species remain unknown, that is, remain to be discovered. The number could be astonishingly large, perhaps a million or more, if all small animals and protists are included. For comparison, biologists have described about 1.5 million terrestrial plants and animals.

Second, distribution. The Census aims to produce maps where the animals have been observed or where they could live, that is, the territory or range of the species. Knowing the range matters a lot for people concerned about, for example, possible consequences of global climate change.

Third, abundance. No Census is complete without measures of abundance. We want to know not only that there is such a thing as a Madagascar crab but how many there are. For marine life, populations are being estimated either in numbers or in total kilos, called biomass.

To complete the context, it is important to understand the top motivations for the Census of Marine Life. Most importantly, much of the ocean is unexplored. Most of the records in its database are for observations near the surface, and down to 1000 meters. No observations have been made in most of the deep ocean, while most of the ocean is deep.

Another important issue is that diversity varies in space. Marine hot spots, like the rain forests of the land, exist off for large fish off the coasts of Brazil and Australia. The goal is to know much more about marine hot spots, to help conserve these large fish. Their abundance and thus their diversity is changing, especially for commercially important species. Between 1952 and 1976, for example, fishermen and their customers emptied many areas of the ocean of tuna.

The Census has evolved a strategy of 14 field projects to touch the major habitats and groups of species in the global ocean. Eleven field projects address habitats, such as seamounts or the Arctic Ocean. Three field projects look globally at animals that either traverse the seas or appear globally distributed: the top predators such as tuna and the plankton and the microbes. The projects employ a mix of technologies. These include acoustics or sound, optics or cameras, tags placed on individual animals that store or report data, and genetics, as well as some actual capture of animals. The technologies complement one another. Sound can survey large areas in the ocean, while light cannot. Light can capture detail and characters that sound cannot. And genetics can make identifications from fragments of specimens or larvae where pictures tell little.

This mix of curiosity, need to know, technology, and scientists willing to investigate the unexplored and undiscovered will result in a Census of Marine Life in 2010 that provides a much clearer picture of what lives below the surface around the globe. Several reasons make such a report timely, indeed urgent. Crises in the sea are reported regularly. One recent study predicted the end of commercial fishery globally by 2050, if current trends persist. Better information is needed to fashion the management that will sustain fisheries, conserve diversity, reverse losses of habitat, reduce impacts of pollution, and respond to global climate change. Hence, there are biological, economic, philosophical and political reasons to push for greater exploration and understanding of the ocean and its inhabitants. Indeed, the United Nations Convention on Biological Diversity requires signatories to collect information on living resources, but, as yet, no nation has a complete baseline of such information. The Census of Marine Life's global network of researchers will help to fill this knowledge gap, providing critical information to help guide decisions on how to manage global marine resources for the future.

[Text copied from the CoML web site, November 5, 2008]