GROWTH RATES OF JUVENILE ARCTIC COD (BOREOGADUS SAIDA) AND SAFFRON COD (ELEGINUS GRACILIS) IN A WARMING OCEAN
Arctic cod (Boreogadus saida) and saffron cod (Eleginus gracilis) co-occur in the Arctic, but growth data are too few to model how they will respond to changing climate scenarios. In this study, we experimentally measured the temperature-dependent growth, condition and activity levels of each species across 4 temperatures(0, 5, 9 and 16°C) in the laboratory. Age-0 juveniles of both species were collected and live-shipped from the Beaufort Sea in August 2013 to initiate experiments. Results indicated clear physiological and behavioral difference between the two species. Arctic cod demonstrated a cold-water, stenothermic response in that there was limited growth potential beyond 5°C, and there was a sharp decrease in condition, activity, growth and survival at 16°C. In contrast, saffron cod demonstrated a warmer-water, eurythermic response in that growth rates and activity increased linearly up to 16°C, with some indication that condition was negatively impacted at the lowest temperature (0°C). Together, these data indicate saffron cod will be able to better exploit warming conditions than Arctic cod, especially in coastal areas where temperatures already exceed 14°C in the summer and nutrient input is high due to river runoff. These results, coupled with a possible northward shift of other gadid species (i.e., walleye pollock), suggest Arctic cod are highly vulnerable to continued climate change in the Arctic.
Laurel, B. J., NOAA-AFSC, USA, email@example.com
Spencer, M., NOAA-AFSC, USA, firstname.lastname@example.org
Copeman, L. A., Oregon State University - CEOAS, USA, email@example.com
Time: 16:00 - 18:00
Location: Poster/Exhibit Hall
Presentation is given by student: No