Upgrades of coastal protection infrastructure affect benthic communities

Sea level rise, storm surges, aging and wear are forcing upgrades to breakwaters and seawalls to protect coastal areas from erosion and inundation. Such upgrades involve the introduction of new material which may consequently act as an ecological disturbance that can alter established marine communities and ecosystem function. Mitigating ecological impacts requires an understanding of how species assemblages are affected by such works.
Here, we use the major upgrade of a regularly wave-overtopped breakwater as a case study to evaluate the impacts of upgrades to hard coastal protection structure on benthic rocky reef communities. An asymmetrical Before-After Control-Impact (BACI) experimental design was used to test interactive effects of the infrastructure upgrades on benthic communities.
While benthic assemblages were not significantly different from controls prior to the upgrade, improving the defensive capacity of the breakwater significantly changed community structure. Notab...