Highlights
• Elevated pCO2 reduced larval survivorship by 37%, but elevated temperature had a greater effect reducing larval survival by 71%.
• Combined stressors reduced larval survivorship to megalopae by 80%.
• Larval morphology and ash free dry weight were not different among treatments.
• Variability among broods suggests there is potential for adaptation within the species.
Abstract
Greenhouse gas emissions are increasing ocean temperatures and the partial pressure of pCO2, resulting in more acidic waters. It is presently unknown how elevated temperature and pCO2 will influence the early life history stages of the majority of marine coastal species. We investigated the combined effect of elevated temperature (30 °C control and 32 °C treatment) and elevated pCO2 (450 μatm control and 1100 μatm treatment) on the (i) growth, (ii) survival, (iii) condition, and (iv) morphology of larvae of the commercially important Florida stone crab, Menippe mercenaria. At elevated temperature, larvae exhibited a significantly shorter molt stage, and elevated pCO2 caused stage-V larvae to delay metamorphosis to post-larvae. On average, elevated pCO2 resulted in a 37% decrease in survivorship relative to the control; however the effect of elevated temperature reduced larval survivorship by 71%. Exposure to both elevated temperature and pCO2 reduced larval survivorship by 80% relative to the control. Despite this, no significant differences were detected in the condition or morphology of stone crab larvae when subjected to elevated temperature and pCO2 treatments. Although elevated pCO2 could result in a reduction in larval supply, future increases in seawater temperatures are even more likely to threaten the future sustainability of the stone-crab fishery.
Gravinese P. M., Enochs I. C., Manzello D. P., van Woesik R., in press. Warming and pCO2 effects on Florida stone crab larvae. Estuarine, Coastal and Shelf Science. Article (subscription required).
