The Department of Conservation (DOC) recently published the threat classification for New Zealand’s freshwater invertebrates.
The assessment considered 644 invertebrate taxa, including mussels, koura/freshwater crayfish, beetles, limpets, snails, caddisflies, stoneflies and mayflies. It is the first time a systematic assessment of the threat status of most freshwater invertebrate groups has been undertaken.
The New Zealand freshwater invertebrate threat classification panel, led by the Department of Conservation, determined that a quarter of the freshwater invertebrate fauna were classified as threatened or at risk.
“Such a systematic assessment of all the species gives us a good baseline to assess threats to freshwater invertebrates against in the future”, said DOC’s Freshwater Technical Advisor, Natasha Grainger.
"The sorts of threats that these species face include habitat loss, altered flow regimes, pressure from introduced fish and poor water quality,” she said.
In the past we have only assessed the taxa considered threatened or at risk. This wider assessment gives us a much better understanding of the conservation status of New Zealand’s freshwater invertebrates.
Nearly 27% of the species could not be assessed due to lack of information. Many of New Zealand’s freshwater invertebrates are not well known, small and often cryptic. More well known species such as koura/freshwater crayfish and mussels are important for Maori and are harvested recreationally.
DOC will use the threat classification to consider how to improve the conservation status of freshwater invertebrates in New Zealand.