Shellfish reefs, particularly mussels, can form large areas of habitat that are vital to their infaunal communities (Cole and McQuaid, 2010), but past research has shown that as calcifying organisms, they are the most vulnerable to warming and acidification (Kroeker et al., 2013a; Parker et al., 2013). On temperate Australian rocky shores, habitats created by the native mussel Trichomya hirsuta, and to a lesser extent, the invasive mussel Mytilus galloprovincialis support a local diversity of annelids, crustaceans, molluscs, and echinoderms (People, 2006; Cole, 2010). Eastern Australia is a climate change “hot-spot” with sea surface temperatures in this region increasing three times faster than the global average (Wernberg et al., 2011; Hobday and Pecl, 2014), and oceans are acidifying worldwide (Collins et al., 2013). The invasive M. galloprovincialis is relatively tolerant to environmental change (Hiebenthal et al., 2013); whereas little is known about the tolerance of T. hirsuta. As the oceans warm and acidify, M. galloprovincialis may have the capacity to replace T. hirsuta as the dominant biogenic habitat on the Australian rocky shores. Any changes in the biogenic mussel habitat could alter the infaunal communities, with downstream consequences for dependent organisms. Such consequences will have an impact on the natural communities and the success of current and future shellfish reef restoration projects (Pereira et al., 2019).
If natives are replaced by hardier shellfish, do we think organisms will adapt to consume the new shellfish? Perhaps softer shelled mussels move in to the territory, will these areas be more susceptible to storm surges and wave energy? The new species may temporarily sound good but could be quickly destroyed by storm systems. This may enable the new species to spread out further and possibly benefit, or lead to the softer shelled mussels demise. Could the stronger storm systems associated with climate change put more stress on these oyster beds?