WP 6 leader: Hans-Otto Pörtner   Hans.Poertner (at) awi.de AWI

Objectives:

• Identify critical stages in the life cycle (e.g. eggs, larvae) of functionally important marine organisms based on performance measures as indicators of sensitivity to ocean acidification
• Analyse physiological mechanisms defining performance levels and sensitivity
• Estimate acclimation capacity (gene expression capacity) for that mechanism as the background of physiological plasticity
• Quantify impact and tolerance thresholds (tipping points)
• Assess interaction between ocean acidification (OA) and ocean warming
• Compare responses and mechanisms in different populations of a species (e.g. in a climate gradient) reflecting potential for evolutionary adaptation (genetic differences)

Description of work and role of participants:

Experiments will be conducted on representative organisms from key functional or commercially important groups (e.g. calanoid copepods, bivalves, infaunal bioturbators like echinoids and thalassinidean shrimp; squid and fish).

T6.1: Sensitivity of critical and early life stages to OA will be assessed through analyses of rates and normality of development, growth, reproductive success, integrity of calcified structures, metabolic and acid-base regulation (AWI, IFM-GEOMAR, PML)

T6.2: pH regulation capacity in different body compartments of the animal will be assessed as a potential mechanism shaping sensitivity (AWI, IFM-GEOMAR, PML)

T6.3: Regulation capacity will be related to changes in gene expression (AWI, IFM-GEOMAR, PML)

T6.4: Responses to CO2 of different populations, e.g. in a latitudinal cline, will be compared to investigate potential evolutionary adaptation (AWI, IFM-GEOMAR, PML)