Preview

PDF Not available 1Mb

Habitat selection by 3 Juan de Fuca Ridge gastropod species relates to their thermal environment. Both collections and images taken along transects document the small-scale abundance patterns of each species with respect to temperature and distance from vent flows. Lepetodrilus fucensis and Depressigyra globulus were most abundant at distances from vent flows of 0 to 25 cm in warm fluids with high temperature variability (10 ± 5°C) over several time scales. Both species were also abundant at 26 to 50 cm, where temperatures were lower with less variability (4 ± 1°C). Provanna variabilis was most abundant from 51 to 75 cm, where temperatures were stable (3 ± 0.5°C). All species were absent where maximum fluid temperatures reached 18°C and their substratum coverage was related to temperature. When presented with a choice in vent fluids from 10 to 2°C, L. fucensis and D. globulus moved to areas with temperatures above 5°C, while P. variabilis showed no preference. In species-specific temperature preference experiments, L. fucensis and D. globulus aggregated between 5 and 13°C, while P. variabilis occupied areas with significantly lower temperatures from 4 to 11°C. These experimental temperature preferences correspond with their thermal environments. Upper temperature limits are moderate; extreme abiotic variability in higher temperature fluids may constrain these 3 species. We conclude thermal conditions are a primary determinant of habitat selection, thereby driving gastropod abundance patterns. However, other factors likely contribute. Space competition nearest vent flows may result in the displacement of individuals of these species to low quality habitats.

Item Type:	Refereed Article
Keywords:	thermal variability, abundance patterns, hydrothermal vent, lepetodrilus fucensis, Depressigyra globulus, Provanna variabilis, preferences
Research Division:	Biological Sciences
Research Group:	Ecology
Research Field:	Ecological physiology
Objective Division:	Environmental Management
Objective Group:	Marine systems and management
Objective Field:	Marine biodiversity
UTAS Author:	Bates, AE (Dr Amanda Bates)
ID Code:	76507
Year Published:	2005
Deposited By:	Sustainable Marine Research Collaboration
Deposited On:	2012-03-07
Last Modified:	2013-03-13
Downloads:	1 View Download Statistics