Deborah Purce
Marine and Estuarine Science Program 
Department of Biology

MSc Completed Winter 2007

BA Biology, Lewis & Clark College, Portland OR.  2001



Project:  Comparative ecophysiology of two geographically separated populations of the scallop Nodipecten subnodosus

Abstract:  In December of 2005 laboratory reared Lion’s Paw scallop (Nodipecten subnodosus) spat from Gulf of California and Pacific coast populations were reciprocally transplanted to Gulf and Pacific coast field sites in Baja California Sur, México.  During summer of 2005, physiological measurements were taken: oxygen consumption, ammonia production, filtration rates and feces composition were measured in the field using a portable chamber flow-through system.  Scallop energy consumption, absorption efficiency, absorbed energy, scope for growth, growth efficiency and adductor muscle body condition were quantified.  Biochemical composition of scallop adductor muscle tissue was also determined and the effects of time (early vs. late summer), site (Gulf vs. Pacific) and population (Gulf vs. Pacific) were compared for all variables using a three-way fixed-factor ANOVA.  We found that energy intake and expenditure were significantly affected by time, site and population factors.  Results suggest that scallop energy acquisition and growth efficiency are highest during the earlier, cooler part of the summer in Baja and, to a lesser degree, at the Pacific site where food availability is highest.  Significantly higher respiration was measured for the Pacific scallop population, leading to significantly lower SFG and K2.  This indicates a significant physiological advantage for Gulf scallops during suboptimal growth conditions that exist during summer months on both coasts of the Baja peninsula.
 
    This work was done in collaboration with Dr. Alfonso Maeda at Centro de Investigaciones Biologicas del Noroeste and Dr. Volker Koch at Universidad Autonoma de Baja California Sur.  Partial funding for my project was through a SEASPACE scholarship.

Affiliations:

GK-12 Fellowship:   
As a NSF sponsered GK-12 fellow here at Western I had the unique opportunity to work in a dynamic partnership with a local 7th/8th grade middle school teacher and spend two days a week team teaching in her classroom.  The goals of our partnership focus on:
1) The successful implementation of a newly adopted inquiry based science curriculum.
2) Defining a model for successful science learning in a district with a predominantly Hispanic and largely migrant student demographic. 

ASLO Minorities in Aquatic Sciences Program:
I am a member of the ASLO MAS program sponsored by NSF and Hampton University.  This program provides an opportunity for minority students in marine or limnological science to attend annual meeting of the American Society of Limnology and Oceanography.  Participants have the chance to present their research or posters and to meet with fellow scientists and students of color.  Travel, meeting registration fees, as well as room and board are covered by the program.

School for Field Studies:
The School for Field Studies offers undergraduates a distinct study abroad experience allowing them to focus their studies on local environmental issues in one of five international settings.  I worked at SFS’s Center for Coastal Studies in Baja California Sur for two years as an intern and researcher.  SFS offers many unique academic and employment opportunities at international field sites and at their headquarters in Boston, MA.