tailieunhanh - Freshwater Bivalve Ecotoxoicology - Chapter 10

Biomarker trả lời của Trai sò Unionid chất gây ô nhiễm môi trường Unionid trai sinh thái và kinh tế quan trọng trong hệ sinh thái thủy sinh. Sinh khối unionids có thể vượt quá sinh khối của tất cả các sinh vật đáy khác một thứ tự cường độ (quốc vương nước Abyssinie năm 1966; Layzer, Gordon, và Anderson 1993), và sản xuất (từ 10-20 g khô mass/m2/yr) có thể bằng rằng bởi tất cả các macrobenthos khác trong dòng nhiều (Strayer et al. 1994). Do đó, unionids có thể đóng vai trò quan trọng trong chế biến hạt, giải. | 10 Biomarker Responses of Unionid Mussels to Environmental Contaminants Teresa J. Newton and W. Gregory Cope INTRODUCTION Unionid mussels are ecologically and economically important in aquatic ecosystems. The biomass of unionids can exceed the biomass of all other benthic organisms by an order of magnitude Negus 1966 Layzer Gordon and Anderson 1993 and production range 1-20 g dry mass m2 yr can equal that by all other macrobenthos in many streams Strayer et al. 1994 . Thus unionids may play important roles in particle processing nutrient release and sediment mixing Vaughn and Hakenkamp 2001 Strayer et al. 2004 . Mussels also serve as food for aquatic mammals including raccoons muskrats and otters Van der Schalie and Van der Schalie 1950 . Historically unionids provided a supplemental food source to indigenous peoples prior to European settlement but large-scale commercial interest in unionids did not develop until the mid-1800s Claassen 1994 . Soon thereafter unionids were extensively harvested for the production of pearl buttons and presently unionid shells are used in the multimillion dollar Asian cultured-pearl industry Anthony and Downing 2001 . Overharvesting widespread habitat destruction pollution land-use change and invasive species introductions have caused many unionid populations to decline or disappear. In North America most species are now extinct or imperiled and unionids are widely recognized as one of the most imperiled plants or animals on the continent Master et al. 2000 . Although not sufficiently documented exposure to toxic contaminants may also be contributing to these declines. There are few instances where chemical spills and other point sources of contaminants have caused localized mortality Sheehan Neves and Kitchel 1989 Fleming Augspurger and Alderman 1995 however widespread decreases in density and diversity are more likely to result from the subtle pervasive effects of chronic low-level contamination Naimo 1995 . There is convincing .