Location
UNLV Student Union
Start Date
13-1-2009 8:00 AM
End Date
14-1-2009 6:00 PM
Description
Las Vegas Bay (LVB) of Lake Mead receives combined flows of tertiary treated wastewater effluent, urban runoff, and groundwater from the Las Vegas metropolitan area. This study examined the potential for endocrine disrupting effects of these anthropogenic inputs on male largemouth bass (Micropterus salmoides). Adult male bass were collected at two sites within Lake Mead: Overton Arm (OA, reference site), and Las Vegas Bay (LVB). Post-spawn fish were collected in July 2007 (n = 6-10 per site) and pre-spawn fish in March 2008 (n = 13 per site). Post-spawn fish were characterized by regressed testes whereas pre-spawn bass had full-grown gonads. Mean fish lengths and weights did not vary between sites or sampling times. Pre-spawn LVB males had lower plasma 11-ketotestosterone (KT), higher estradiol-17β (E2), higher E2/KT ratio, higher hepatosomatic index (ratio of liver to body weight), higher hematocrit values, and higher condition factor compared to OA males. However, no significant differences were evident in the gonadosomatic index (ratio of testes to body weight) of either pre-or post-spawn males from the two sites. In post-spawn males, no significant site-associated differences were detected for any of the parameters measured. Overall, these results suggest the existence of site-specific environmental influences on several indices of endocrine condition and health of pre-spawn male largemouth bass in Lake Mead, and are generally consistent with outcomes from previous studies that suggested the occurrence of altered endocrine and reproductive condition in male common carp from LVB.
Keywords
Endocrine disrupting chemicals in water; Largemouth bass; Micropterus salmoides; United States – Lake Mead; Water – Pollution
Disciplines
Aquaculture and Fisheries | Environmental Health and Protection | Environmental Indicators and Impact Assessment | Environmental Monitoring | Fresh Water Studies
Language
English
Included in
Aquaculture and Fisheries Commons, Environmental Health and Protection Commons, Environmental Indicators and Impact Assessment Commons, Environmental Monitoring Commons, Fresh Water Studies Commons
Assessment of Endocrine and Gonadal Condition of Male Largemouth Bass from Lake Mead, Nevada
UNLV Student Union
Las Vegas Bay (LVB) of Lake Mead receives combined flows of tertiary treated wastewater effluent, urban runoff, and groundwater from the Las Vegas metropolitan area. This study examined the potential for endocrine disrupting effects of these anthropogenic inputs on male largemouth bass (Micropterus salmoides). Adult male bass were collected at two sites within Lake Mead: Overton Arm (OA, reference site), and Las Vegas Bay (LVB). Post-spawn fish were collected in July 2007 (n = 6-10 per site) and pre-spawn fish in March 2008 (n = 13 per site). Post-spawn fish were characterized by regressed testes whereas pre-spawn bass had full-grown gonads. Mean fish lengths and weights did not vary between sites or sampling times. Pre-spawn LVB males had lower plasma 11-ketotestosterone (KT), higher estradiol-17β (E2), higher E2/KT ratio, higher hepatosomatic index (ratio of liver to body weight), higher hematocrit values, and higher condition factor compared to OA males. However, no significant differences were evident in the gonadosomatic index (ratio of testes to body weight) of either pre-or post-spawn males from the two sites. In post-spawn males, no significant site-associated differences were detected for any of the parameters measured. Overall, these results suggest the existence of site-specific environmental influences on several indices of endocrine condition and health of pre-spawn male largemouth bass in Lake Mead, and are generally consistent with outcomes from previous studies that suggested the occurrence of altered endocrine and reproductive condition in male common carp from LVB.
Comments
File: Poster