Literaturdatenbank
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Haramis, M., Henry, P. F. P., Day, D. D., & Marshal, D. W. (2006). Use of a traditional harvest method to sample diamondback terrapins in winter in chesapeake bay. Patuxent Science Meeting 2006 Poster Abstract.
Added by: Admin (14 Aug 2008 20:33:43 UTC) |
| Resource type: Journal Article BibTeX citation key: Haramis2006 View all bibliographic details  |
Categories: General Keywords: Emydidae, Habitat = habitat, Malaclemys, Malaclemys terrapin, Nordamerika = North America, Schildkröten = turtles + tortoises Creators: Day, Haramis, Henry, Marshal Collection: Patuxent Science Meeting 2006 Poster Abstract |
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| Abstract |
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Harvest of Diamondback Terrapins (Malaclemys terrapin terrapin) in Chesapeake Bay historically took place in the winter months using dredges of various configurations. We worked with Dwight Marshall, an experienced terrapin harvester from Smith Island to document these methods first hand, to assess the effects of commercial harvest on local populations, and potentially adapt the methods for scientific study. In winters 2003 through 2005, we used a modified crab scrape to dredge 1220 terrapins at 7 hibernacula, 6 of which were located in the Tangier Sound area. The scrape was framed with cold-rolled steel stock, was 1.7 m wide and trailed an 8-cm mesh nylon bag to retain terrapins. The leading bar of the scrape was equipped with 30 15-cm long downward facing teeth to help remove terrapins from soft bottom sediments. Hibernacula were located in semi-protected estuarine bays normally within 300 m from nearby marsh. These sites were characterized by water depths of 2 to 4 m and bottoms of moderately soft mud. These conditions provided for good tidal circulation, even under ice cover, while at the same time protecting against dewatering at extreme low storm tides. The cold winters of 2003 to 2005 (< 7 degree C February water temperatures) produced well-populated hibernacula of virtually all adult terrapin. The dredge did not injure terrapins and proved to be an efficient capture method capable of landing 200 terrapins/hr in some circumstances. We found terrapins to be abundant at most sites and site-specific sex ratios to vary widely. Most importantly, our sampling revealed the relative ease of harvest of large numbers of adult females from estuarine bay hibernacula. Removal of large numbers of breeding age females could have long-term effects on local terrapin populations.
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