Physical characteristics of persistent deep-water spawning sites of capelin: Importance for delimiting critical marine habitats

Abstract

In coastal Newfoundland, high abundances of top predators aggregate (biological hotspots) over deep-water (demersal) spawning sites of capelin (Mallotus villosus), the focal forage fish on which most top predators rely for prey. We explore the mechanisms underlying the spatial persistence of hotspot formation by investigating physical characteristics associated with the persistent use of demersal spawning sites of capelin on the northeast Newfoundland coast from 2003 to 2010. The continued presence of suitable spawning sediment (0.5–16 mm) in permanent bathymetric depressions was a key determinant of site use persistence, whereas minimum temperature (~2°C) influenced the use of sites with suitable sediments. We suggest that biological hotspots associated with demersal spawning sites with similar physical characteristics could be used to delineate critical marine habitats for protection throughout the circumpolar distribution of this key forage fish species.

Keywords:

• Bathymetry
• biological hotspot
• capelin
• Mallotus villosus
• sediment size
• spawning
• temperature

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory, University of Copenhagen, Denmark

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory, University of Copenhagen, Denmark

Acknowledgements

Principal funding was provided by NSERC Discovery, Ship Time, and Strategic Project grants to GKD. We are indebted to the captain and crew of the Lady Easton II for their assistance with field work. Thanks also to A. Murphy, C. Burke, D. Porter, C. Rose-Taylor, C. May, D. Rogers, B.B. Harter, E. Maxner, L. Hayhurst and J. Allen.

Notes

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory, University of Copenhagen, Denmark