I am collaborating
with Jon Shurin and Russel Markel
at the University of British Columbia to quantify the settlement
of juvenile rockfishes from the plankton on the west coast of Vancouver
Island. We use SMURFS (Standard Measuring Unit for the Recruitment
of Fishes, see photo) in kelp forests to collect juvenile fish.
SMURFs provide a complex structure that juvenile fish are naturally
attracted to during this phase of their life cycle. Rockfish are
long lived (50-80 years), which makes their populations particularly
vulnerable to the effects of overfishing.
A SMURF
My dissertation will be examining the following questions in relation
to rockfish recruitment for four species of rockfishes found recruiting
to the west coast of Vancover Island (black, yellowtail, copper,
and boccacio). In particular, I will use microsatellite markers
to examine these questions in more detail for black rockfish, Sebastes
melanops.
1. How does the timing and duration of upwelling affect the recruitment
dynamics of different species of rockfishes recruiting to Barkley
Sound, British Columbia? Does the coincidence of spawning with the
timing of upwelling in some years and not others result in high
variance in reproductive success in black rockfish?
2. How do patterns of oceanographic flow in Barkley Sound affect
the abundance of recruits in the sound throughout the season (May-Sept)?
3. How do regional differences in kelp forest size, caused by the
repatriation of sea otters, affect recruitment dynamics? Do larger
kelp forests act as a "magnet" for a greater proportion
of larvae from the adult popultion? How is this affected by the
population structure of adults between Washington and Alaska?
4. What management recommendations can I make to the Pacific Rim
National Park, located in Barkley Sound, as they are planning to
expand to a National Marine Conservation Area in the future? Do
some sites function better than others for recruitment between years?
|
Photo of a juvenile black rockfish (Sebastes
melanops).
Snorkeling on a SMURF at Chrowe Island, in Barkley Sound, British
Columbia.
A juvenile yellowtail rockfish (Sebastes flavidus, top)
versus a juvenile black rockfish (S. melanops, bottom).
Sites where we are measuring recruitment in Barkley Sound. The
white line encompasses Pacific Rim National Park. |
