Bill Kerrison is a legend when it comes to tuna or eels and it was privilege to meet him during a recent Dirty Water tour in the Bay of Plenty. Over several decades he has transferred an estimated 25 million eels around Bay of Plenty dams such as the Matahina on the Rangitaiki River.
New Zealand's longfin eels are one of the world's largest eel species. They have swum up our rivers for around 23 million years. As a species they are more ancient than humans. Yet in just a few centuries our careless destruction of their habitat and overfishing means that longfin eels they are now threatened with extinction.
Eels have an extraordinary lifecycle which hydro dams completely disrupt. Bill has saved mature eels from being killed as they are pushed against the steel gratings of a dam's water intake as they try to migrate downstream to make the long journey to near Tonga to spawn. He has transported young elvers upstream after they have drifted as larvae across the ocean, escaped predators while tiny glass eels in our estuaries only to find their journey upstream barred by the huge rock and concrete structure of dam walls.
Bill's parents had a small commercial fishing boat in the Hauraki Gulf and Bill grew up on the boat. He describes at age 15 being fascinated by seeing huge eels flicking around the piles of the Thames wharf when they tied up to unload.
Sixty seven per cent of our indigenous fish species are classified as threatened or at risk of extinction, including longfin eel which have a threat ranking of "declining." Bill Kerrison still finds many young elvers at his catch and transfer sites but very few large eels. Eels only breed once in their life. If the number of longfins declines further, and too few eels are able to migrate to Tonga to spawn successfully, the population could plummet to extinction.
Bill has spent decades doing all he can to save eels and inspire others. His and wife Ruby's modest home on a hilltop near Galatea in the Bay of Plenty is a mecca for freshwater ecology students and eel lovers. They have recently located two houses to build a lodge to house visiting students and eel researchers from Auckland 's AUT and elsewhere.
Arizona based artist Stephanie Bowman is also passionate about eels. Since June 2011 her social art project "Velvet" the Travelling Tuna Tapestry has inspired schools and community organisations to learn about and seek to protect longfin eel. People around the country have added new panels to the tapestry making "Velvet" longer and longer. "Velvet" is now hanging in the Bush City Kiosk at Te Papa before coming to Parliament on Tuesday 19 March when the petition to save longfin will be presented. You can sign the petition here.
Bill's and Stephanie's efforts on behalf of tuna are inspiring. To improve the outlook for longfin we need to protect our remaining wild rivers so eels have free passage to and from the sea to migrate, spawn, avoid any new hydro dams in rivers where eel are found, clean up our rivers, especially our lowland rivers, and end commercial eel fishing.
The commercial catch for eels was 418 tonnes last year. That's too high given the declining population and when some eels appallingly end up as pet food.