[MARMAM] New Paper Announcement

Dave Duffus dduffus at office.geog.uvic.ca
Mon Aug 8 16:44:07 PDT 2011

For those of you interested in baleen whale predator prey dynamics, or just 
the exciting story of mysids the following paper was recently published in 
Hydrobiologia, DOI 10.1007/s10750-011-0816-z

Predatory disturbance and prey species diversity: the case of gray whale 
(Eschrichtius robustus) foraging on a multi-species mysid (family Mysidae) 

L. J. Feyrer & D. A. Duffus Whale Research Lab, Department of Geography, 
University of Victoria, PO 3060 STN CSC, Victoria, BC V8W 3P5, Canada e-mail: 
laura.joan at gmail.com

Abstract	Why competitive exclusion does not limit the number of coexisting 
plankton species is a persistent question for community ecology. One explanation, 
the intermediate disturbance hypothesis (IDH), proposes that elevated species 
diversity is a product of moderate levels of disturbance that allow the subsequent 
invasion of less competitive species. Here, we assess the shifts in species 
diversity in a mysid (Mysidae Dana, 1850) zooplankton commu- nity, where 
at least 10 species have, over the last 15 years, have come to comprise the 
primary prey base of summer resident gray whales (Eschrictius robustus Lilljeborg, 
1861) in Clayoquot Sound, British Columbia. We evaluate trends in the commu- 
nity structure of mysids (species dominance, diver- sity, and richness) across 
mysid habitat in the study area during the gray whale foraging season (May– 
September) for the period 1996 and 2008. Mysid species composition varies 
among years and diversity has increased as whales shifted their predatory 
focus from benthic amphipods (Ampeliscidae Costa, 1857) to mysids, near our 
starting point in 1996. Holme- simysis sculpta Tattersall, 1933 was the dominant 
species in early years; however, in 2007, the dom- inance shifted to Neomysis 
rayi Murdoch, 1885. The habitat restrictions and life history attributes 
of local populations of coastal mysids leave them vulnerable to the cumulative 
impacts of increased predation pressure by gray whales. This case study presents 
a unique examination implicating predation as an agent of disturbance capable 
of altering the species struc- ture of a local prey community.

For another month or so Laura is out of email range on mat leave, and Dave 
is in the field far enough away so that there is no internet connection, 
so if you cant access the journal, one of us will respond to requests toward 
the end of the month

More information about the MARMAM mailing list