Aotearoa New Zealand’s Hikurangi Margin is a highly dynamic environment, influenced by active tectonic deformation, oceanic currents, sediment transport and anthropogenic activities including trawling. Seafloor seeps are abundant, predominantly along subduction-related accretionary ridges. Seeps sustain highly productive localised ecosystems, including chemosynthetic fauna. The underlying structural complexity, combined with active geomorphological processes, results in food production hotspots, combined with chemosynthetic primary production and biodiversity, potentially supporting commercially important fisheries.
Research shows that numerous species at these seeps are new to science and/or endemic to Aotearoa. Many seeps are directly related to underlying geological complexity that focuses subseafloor gas hydrate accumulations, which are only stable under certain pressure and temperature conditions. Seep fauna are predominantly slow growing, and seep ecosystems may take years to millennia to fully recover from disturbance. Given the sensitivity of seep communities they are particularly vulnerable to disturbance and increasing environmental pressure from changing climate. New data reveals that anthropogenic activities have already impacted the seabed. Furthermore, investigation of earthquake-triggered sediment transport processes demonstrates impact of natural geological disturbances (e.g., submarine landslides and turbidity currents). These data demonstrate the criticality of marine environmental planning, underpinned by evidence-based scientific understanding to achieve a balance of ecosystem and resource sustainability.