Sediment tolerance and mortality thresholds of benthic habitats

Sediment tolerance chambers in the Marine Environmental Manipulation Facility at NIWA Wellington. © Jennifer Beaumont, NIWA

We are investigating the effects that suspended sediment from human activities has on the health and survival of deep-sea species in the South Taranaki Bight.

Project leader: Malcolm Clark, NIWA

Duration: October 2016 – January 2019 
Budget: $300,000 
Status: Ongoing 

Human activities, such as mining and fishing, can generate suspended sediment that affect the health and survival of deep-sea species. We are using innovative laboratory experiments to understand how resilient species are, and how quickly they can recover. 

We have completed trials on two deep-sea animals: dog cockles (Tucetona laticostata) and a sponge (Crella incrustans) found in the Taranaki Bight area. We put collected specimens in seawater to see how they responded to different conditions. The seawater ranged from clean to very murky with a high concentration of suspended sediment. We measured their survival, feeding, respiration, buoyant weight, tissue condition, internal sediment accumulation, and various stress responses such as budding and mucous production over time. After four weeks, we returned the specimens to normal seawater and monitored how well they recovered from our experiment.   

Our research will determine the level of suspended sediment that has an impact on these deep-sea species. From these results, we can predict when management or mitigation strategies will be needed to protect them.

Latest news and updates

Assessing marine ecosystems to improve management

Sustainable Seas National Science Challenge researchers are hoping that marine health data gathered on a recent field trip to Queen Charlotte Sounds will support more integrated management of the ecosystem.

Developing ecosystem-based management principles for NZ

The Sustainable Seas National Science Challenge leadership team have proposed seven major principles for ecosystem-based management (EBM) in Aotearoa New Zealand.

Growing a successful and sustainable Māori marine economy

The Sustainable Seas research team led by Dr John Reid and Dr Jason Mika have identified five key factors that will drive growth of the Māori marine economy: