• Summary

Sea-floor species and suspended sediment

This 1-page 'postcard' summarises research into the resilience of common sponge and dog cockles to suspended sediments.


Human activities, such as mining and fishing, can generate suspended sediment that affect the health and
survival of sea-floor species. This research investigated the impact of suspended sediments on two types of animals: dog cockles and a common sponge.

We collected dog cockles from Taranaki and common sponge from Wellington’s South Coast and took them to a laboratory at NIWA, Wellington. Here, we trialled innovative laboratory experiments to understand how resilient
these species are, and how quickly they can recover from suspended sediment levels that could arise from human activities.

We found:
  • Both survived in the experimentally elevated suspended sediments.
  • Sponges accumulated the sediments internally, but they began to clear these under normal seawater conditions.
We achieved:
  • An effective system for maintaining sediment in suspension – not an easy task!
  • Useful insights that have informed other research projects on ecological effects of suspended sediments.


  • Sea-floor species and suspended sediment

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