This repository contains all data and analysis for the prepared manuscript (title, authors, and abstract below).
Manuscript title: METABOLIC RECOVERY AND COMPENSATORY SHELL GROWTH OF JUVENILE PACIFIC GEODUCK PANOPEA GENEROSA FOLLOWING SHORT-TERM ACIDIFICATION
Samuel J. Gurr*, Brent Vadopalas, Steven B. Roberts, Hollie M. Putnam
*Corresponding author: Fax: Phone:1-401-874-9510 Email: firstname.lastname@example.org
Enhancement strategies in sustainable shellfish industry are critical to satisfy growing demands for food security. The Pacific geoduck, Panopea generosa, is a valuable clam increasing in aquaculture productivity, however as with many commercial shellfish, hatchery rearing poses a bottleneck. Although acute stressors can be detrimental, a growing body of literature supports potential for environmental stress conditioning to improve performance. To test the hypothesis that physiological status is altered by stress conditioning, we subjected juvenile geoduck to repeated exposures of elevated pCO2 in a commercial hatchery setting followed by a period in ambient common garden. Metabolic rate and shell length were measured for juvenile geoduck periodically throughout short-term repeated reciprocal exposure periods (initial 10 day exposure, 14 days in ambient, and a secondary 6 day reciprocal exposure) in ambient (~550 µatm) or elevated (~2400 µatm) pCO2 treatments, and in ambient conditions five months after exposure. Initially, elevated pCO2 significantly reduced metabolic rate by 25%, in comparison to ambient conditions. While shell length did not differ between treatments, it increased by time (3.6% over 8 days). Following 2-weeks in ambient conditions, reciprocal exposure to elevated or ambient pCO2 did not alter juvenile metabolic rates, indicating ability for metabolic recovery when returned to ambient conditions. Unlike the first exposure, shell length was affected negatively during the reciprocal experiment in both exposure histories, however clams exposed to the initial elevated pCO2 showed compensatory growth with 5.8% greater shell length (on average between the two secondary exposures) after five months in ambient conditions. Additionally, clams exposed to the secondary elevated pCO2 showed 52.4% increase in respiration rate after five months in ambient conditions. Early exposure to low pH appears to trigger carry over effects suggesting bioenergetic re-allocation facilitates growth compensation. A variety of life stage-specific exposures to stress can determine when it may be especially detrimental, or advantageous, to apply stress conditioning for commercial production of this long-lived burrowing clam.