On 06 April 2021 this item appeared: What’s in the water? Nationwide interest in EPA programme:
By sampling just a litre of water, groups capture remnants of DNA shed by creatures in the waterway. The eDNA data reveals all the species present — from microbes to mammals. This can indicate the overall health of the ecosystem and draw attention to creatures that are under threat or unwanted pest species.
Environmental DNA, or eDNA, refers to all the tiny traces of genetic material that is left behind as living things pass through water or soil.
From kērēru to kōwhai, and the leaves in the wind, all living things shed genetic information into their local environment. This is called environmental DNA, or eDNA.
For example, a bird flies over a lake and drops a feather. … Likewise, an insect may fall into the lake, and leaves fall from trees. These plants and animals leave behind ‘genetic breadcrumbs’ (such as skin cells and faeces) in the environments they live in.
A bit of investigation showed that back in May 2020 Tim Clapham from Wellington High School took a sample from the river at Waikawa Beach. The results of Sample number: 501185 show the presence of eDNA from cattle, pigs, birds such as shags, pūkeko, silvereye and geese, fish such as flounder and mullet, eels and īnanga, as well as snails, worms and other lifeforms.