Abstracts
SEARCH Open Science Meeting
October 27, 2003
Seattle, Washington, USA
Quantitative Importance of Macrofauna: A Test of Sieve Mesh Size Biases on Sampling in a High Benthic Biomass Area
Rebecca Pirtle-Levy1, Jackie M. Grebmeier2, Lee W. Cooper3
1Ecology and Evolutionary Biology, University of Tennessee, 10515 Research Dr., Suite 100, Knoxville, TN, 37932, USA, Phone 865-974-6160, Fax 865-974-7896, rpirtlel@utk.edu
2Ecology and Evolutionary Biology , University of Tennessee, 10515 Research Dr., Suite 100, Knoxville, TN, 37932, USA, Phone 865-974-2592, Fax 865-974-7896, jgrebmei@utk.edu
3Ecology and Evolutionary Biology, University of Tennessee, 10515 Research Dr., Suite 100, Knoxville, TN, 37932, USA, Phone 865-974-2990, Fax 865-974-7896, lcooper1@utk.edu
The effects of sieve mesh size on estimates of standing stocks of benthic populations was examined on the continental shelf of the Bering and Chukchi Seas, an area with high benthic biomass. Benthic grab samples were collected on a 1.0mm mesh, and materials passing through that screen were collected on 0.5mm mesh. Collections were made at 16 stations occupied on the CCGS Sir Wilfrid Laurier in July 2003 during an annual cruise associated with the Bering Strait Environmental Observatory in both the Bering and Chukchi Seas.
Results indicate that both mesh sizes retain similar percentage ranges of total individuals at each station, 30 – 80% for 0.5mm mesh and 20 – 70% for 1.0mm mesh, when compared to combined abundances of both mesh sizes. The total mass collected on the larger 1.0 mm screen ranged from 95 to 99% of all biomass collected on both screens; the remaining wet biomass collected on the 0.5 mm mesh ranged from 0.5 to 2.0% of total biomass on both screens. We are currently evaluating differences in benthic faunal diversity for the two screen sizes using the Shannon-Weaver diversity index. It appears, however that sampling with a 1.0 mm mesh is a small enough sieve size to adequately estimate benthic biomass on the continental shelves of the Bering and Chukchi Seas and that the macrozoobenthos lost through this sieve size is a relatively small percentage of total biomass.
This is of significance for budgeting and modeling the food needs of benthic-feeding apex predators such as gray whales, walruses, bearded seals and diving sea ducks that may be impacted by the arctic biological changes that will be one of the foci of the SEARCH research program. Future investigations will focus on the influence of environmental factors such as the cycling of chlorophyll within sediments over annual cycles. We will also investigate the validity of the 1.0 mm screen size in deeper waters where benthic macrofauna are quantitatively less important, such as on the outer continental shelf being studied in the Shelf-Basin Interaction program.
Abstract Categories: Changes in the Sea, Student Poster
Back to main abstract page
To view the list of records returned in your search you can use your browser's
back button, or perform the same search again:
| 