Temperate Australian intertidal invertebrates are becoming increasingly vulnerable to a range of climate change-driven stressors. These vulnerabilities are heightened due to many intertidal invertebrates already living close to their upper thermal limits, leaving them with limited capacity to tolerate additional climatic stress.
Key morphological differences of species such as shape variation can be studied in populations across environmental gradients to understand what climate change impacts are affecting species the most .Species may have altered adaptive responses across different environmental gradients which affect their overall fitness under climate change.
There are many types of barriers to gene flow for marine coastal invertebrates including physical (currents) and oceanographic (water temperature). Phylogeography allows us to see how populations have responded to past environmental change, which we can compare to current studies to understand how populations are responding to contemporary climate change.
This study examined pairwise differences of sea surface salinity, sea surface temperature and wave exposure across twenty sites in temperate Australia to explore morphological variation and population genetics of six rocky intertidal invertebrate species. Multivariate analysis of morphological variation revealed significant differences among sites, including increasing morphological divergences along the west–east longitudinal gradient driven by increasing temperature and salinity.