Species-specific responses to tectonic disturbance
Species responses to environmental perturbations can be strongly
governed by life-history strategies and habitat requirements (Sousa
1984; Ewers & Didham 2006). Although disturbances are critical for
liberating new territories for recolonization, the survival of small
refugial patches can still inhibit population genomic turnover in the
disturbed patch (Fraser et al. 2018a). In our study, two species
that tolerate subtidal conditions showed little or no evidence of
historic disturbance. Specifically, only limited structuring was
detected in the subtidal kelp D. willana . Additionally, the
facultatively subtidal amphipod, P. karaka , was represented as a
single, broadly panmictic population. This amphipod has enhanced
swimming potential in water column (Fincham 1974; Lowry & Stoddart
1986) and has been reported from deeper sublittoral zones (Lowry &
Stoddart 1983). These characteristics have possibly facilitated the
survival of P. karaka through the uplift event by promoting
host-switching to non-disturbed subtidal macroalgae such asMacrocystis pyrifera (Alonso 2012). On the contrary, while the
chiton, O. neglectus, has the potential to survive under boulders
on rocky shores (Salloum et al. 2020), the populations in Akatore
did not persist through the coastal uplift and disruption of theDurvillaea hosts has left a significant genomic signature in the
chiton populations. These findings suggest that microhabitat and
dispersal ability can substantially influence species’ responses to
major disturbance.
In summary, multispecies demographic analyses reveal a remarkably
synchronous and concerted community-wide response to large-scale
prehistoric disturbance. Moreover, our findings indicate that
community-level genomic studies present a key approach for tracking the
effects of major ecological perturbations increasingly expected under
global change scenarios (e.g. Shive et al. 2018; Newman 2019; Ward et
al. 2020).