Our experiment regarding mussel valve closures has implications for the roles of mussels as ecosystem engineers. When closed, mussels cease feeding and thus are not filtering water. This can affect mussel growth and filtering activity. Given that mussels under high temperatures remained closed longer, their condition and filtering capacity may be affected. Indeed our results corroborate previous studies suggesting that mussels are sensitive to high temperatures. Given the ecological and economic roles of bivalve globally, our results have societal implications for the sustainability of bivalve fisheries and aquaculture and the role of bivalves in water filtration.
Secondly, we found no effect of OA on animal behaviour in both of our empirical experiments, and found that reports of OA effects on fish behaviour may be compounded by poor methodology (low sample size) and publication bias. These results corroborate well with a study recently conducted by F. Jutfelt and colleagues in which the strong effects of OA on coral reef fishes reported in previous studies could not be empirically replicated. Collectively, these results suggest that OA may not have as severe of an effect on animal behaviour as has been thought for the past decade. This has societal implications for management and conservation strategies for fish populations in the face of ocean acidification. For example, management strategies using previous reports of OA on fish behaviour may be unnecessarily altering management practices. Ultimately, the results of this project cast doubt on OA effects on animal behaviour.
At a broad scale, the project's results have major implications for how science regarding environmental stress and animal behaviour is conducted. The meta-analysis found that severe effects of oA were restricted to studies with low samples sizes - specifically studies that employed a sample size of less than 30 fish per experimental treatment. Furthermore, the sea star experiment suggested that, when sample sizes are low, spurious effects can be detected that may not actually exist if experiments are not repeated. These findings have important implications for how experiments regarding climate change and animal behaviour are conducted, suggesting that to have confidence in experimental results, such studies should, when possible, employ a baseline sample size of 30 individuals and should repeat behavioural assays. Furthermore, the results provide two easy-to-assess aspects of global change-behaviour studies for scientists and non-scientists to determine the reliability of results from global change-behaviour studies.
