| EMERGENCE PATTERNS OF CAPELIN (MALLOTUS VILLOSUS) AT BEACH AND DEMERSAL SPAWNING SITES ON THE NORTHEAST COAST OF NEWFOUNDLAND |
| PENTON, P. *Department of Zoology, Duff Roblin Building, University of Manitoba, Winnipeg, Manitoba, Canada, umpenton@cc.umanitoba.ca; Davoren, G.K.*; Montevecchi, W.A. Cognitive and Behavioral Ecology Program, Departments of Psychology, Biology and Ocean Sciences, Memorial University of Newfoundland, St. John’s, Newfoundland, Canada; Andrews, D.W. Biology Department, York University, Toronto, Ontario, Canada. |
| Wind induced changes in the water column (Coastal Water Mass Replacement) are thought to be the major factor in determining the recruitment of capelin (Mallotus villosus), the focal forage fish species in the northwest Atlantic. Onshore winds have been shown to cause an increase in water temperature in coastal areas, triggering the synchronous emergence of capelin larvae from sediments at the beach into predator-poor and prey-rich conditions that are favourable for larval survival. Although capelin in Newfoundland are thought to spawn primarily on beaches, demersal (deep-water) spawning sites (18-38 m) have recently been discovered in near shore regions (2.5-18 km) on the exposed northeast coast of Newfoundland. We investigated whether wind events influenced the thermal properties of water temperatures at two beach sites in 2004 and five demersal sites in 2004 and 2005 during the post-hatch period. Wind events oriented along the shore resulted in frequent and sharp increases in bottom temperatures at all demersal sites but not at the beach, possibly due to consistently high temperatures at beach sites throughout the post-hatch period. Capelin larvae in the study area did not appear to emerge in response to a warm water cue, as shown at beach sites in other regions of Newfoundland. Instead, we hypothesize that larvae simply emerge from the sediment upon hatching. |
| back |
|
