PAST RESEARCH

Green Turtles, Shoalwater Bay

In order to ensure fisheries bycatch mitigation efforts are effective (from a demographic perspective) and  targeted at those populations/regions most at risk, we investigated ‘equivalency ratios’ to ensure proposed Biodiversity Offsets for the bycatch of seabirds and sea turtles in fisheries are assessed on a like-for-like basis.  This work addresses a significant challenge in our ability to mitigate bycatch, by taking into consideration fundamental life-history characteristics exhibited by long-lived species, such as delayed breeding (up to 38 years in sea turtles).  The results provide a novel tool to estimate equivalency ratios, particularly for those species which are poorly studied and have little or no demographic data.  In addition, we developed a Geographic Assignment model where seabird bycatch of unknown provenance can be assigned to colony of origin using biochemical markers (e.g., trace metal concentrations).  The model allows wildlife managers to identify colonies that are at the greatest risk from fisheries bycatch and establish a stronger link between seabird population trends and known bycatch events.

Collaborators:  Josh Donlan and Larry Crowder

Gannet Is., Labrador

In north-eastern Canada many seabird species migrate southward in the fall in large mixed-species flocks.  In Newfoundland and Labrador, local residents (many in remote communities) have traditionally relied on these migrating seabirds as a source of food.  Unfortunately, some seabird species exhibit similar color patters, or are of similar size, thus telling them apart from a distance can be a challenge for hunters and non-target species are often killed by accident ('bycatch').  In order to ensure the long-term sustainbility of harvested species, I examined Razorbill bycatch rates using fourteen years of capture-mark-recapture and movement data.  Results of this research provided the first evidence of a substantial decline in Razorbill populations at the Gannet Islands and identified a range of management techniques that could be employed to reduce accidental mortality in the hunt (see 2009 Publications).

Collaborators:  Ian Jones, Tony Diamond, and Greg Robertson