US EPA

3238504 

Journal Article 

Impact of climate change stressors on marine invertebrate life histories with a focus on the Mollusca and Echinodermata 

Byrne, M 

2010 

169-212 

WOS:000314785200007 

Global warming and increased atmospheric CO2 are causing the oceans to warm and acidify. These stressors are likely to have deleterious impacts on marine biota, particularly on early life history stages. To address questions on future vulnerabilities, the thermo- and pH tolerance of fertilisation and development of sea urchins and bivalves is reviewed and placed within the setting of projected ocean change using data from single stressor studies of estuarine, coastal and shallow water species. Fertilisation in many urchin and bivalve species exhibit a broad tolerance being robust to warming or acidification beyond stressor values projected for 2100 (2100: ca. +2-4 degrees C; pH -0.2-0.4 units, IPCC 2007). This is also the case for a number of other invertebrate taxa. It appears that fertilisation may not be a suitable indicator to discern the effects of climate change on marine life histories. Developmental stages, however, exhibit greater sensitivity to thermal and pH stress. Early embryos of some species are vulnerable within the range of near future warming. For embryos that reach the larval stage in a warm ocean, increased pCO(2) and acidification may have a negative effect on larval physiology due to hypercapnia and decreased bioavailability of the carbonate ions needed to produce their skeleton. Developmental bioassays with an initial focus on early endpoints (cleavage, gastrulation) provide a model system with which to assess and monitor the interactive effects of ocean warming and acidification. Animal development can fail at any stage and determination of the sensitivities of life stages to climate change stressors is essential. If embryogenesis fails due to warming then the question of compromised larval calcification may not be relevant. Marine life history stages are exposed to a plethora of stressors in addition to those from climate change and the interaction between stressors has potential for deleterious impacts, but these are difficult to predict. Most available data on effects of climate change stressors on marine life histories are for robust species used as model organisms for laboratory research and aquaculture. Studies to date indicate that the response of marine embryos and larvae to climate change stressors varies, even between closely related species, making it difficult to extrapolate broadly on potential climate change effects. Multifactorial experiments with marine embryos using methods adopted from ecotoxicology provide a framework to determine the potential effects of climate change on marine biota. Although it is unlikely that generic indicator species will be identified for monitoring impacts of ocean change, empirical data for a phylogenetically diverse suite of species from different habitats are required to assess this. A gloomy assessment is presented, but there is potential for in-built adaptive (genetic) and acclimation (phenotypic plasticity) capacity for some species. This, along with different tolerance thresholds, will influence species vulnerability and the potential winners and losers in the face of ocean regime change.