Meeting Abstract
Surface waters around the San Juan Islands in the Pacific North West are directly affected by Arctic ice melt via the Fraser River, the second largest in the region. Data collected in these waters by the Friday Harbor Labs weather station to the south of the river reveal an increase in the frequency of low salinity waters (21) into the area during the spring and summer months when echinoderm larvae are developing. The present study investigated whether protein profiles of eggs and larvae from sea stars (Pisaster ochraceus) from a location directly exposed (Cantilever Point, CP) to the Fraser River and a location less exposed (Snug Harbor, SH) differed. Greater expression of high molecular weight (HMW) proteins was observed in the eggs produced by CP females than for those produced by SH females. CP larvae exposed to 4 salinity fluctuations (low salinity 21-22) during development, expressed HMW proteins (404, 271, and 166kDa) not present or faintly expressed by those in the controls (30 ppt). CP larvae in 21 ppt. did not differ significantly in size from those in 30; while SH larvae in 21ppt. were significantly smaller. Interestingly, proteins expressed by SH larvae in low salinity differed from those expressed by CP larvae under similar conditions. In instances were larvae from both locations expressed similar proteins (e.g. 244, 135, and 77kDa) the expression of these proteins was significantly higher for CP larvae. As global warming continues to increase the rate of glacial melting, females from sites exposed to the Fraser River might invest specific proteins in their eggs that ensure optimal physiological conditions (e.g. active transport of ions with the help of Na+/K+ATPase, Ca2+ATPase, and organic anion transporters) for larval growth and development.
