The Department of Conservation is responsible for managing the scientific reserve, the Kapiti Coast District Council for residential development and drainage, and Greater Wellington Regional Council for flood and erosion protection.
The report says based on the current level of sediment deposit the upper estuary is expected to infill rapidly and become muddier and less diverse.
The report's conclusion is that "such conditions limit food availability for fish and birdlife and show the ability of the estuary to assimilate sediment loads is currently exceeded".
The Whitebait Network spokesmen say the degradation of the estuary is an indictment on the management of the reserve and makes the movement of whitebaiter vehicles on the beach pale into insignificance.
"It's not whitebaiters who cause problems but significant modifications to the estuary by the very agencies which are charged with protecting the environment."
They say many thousands of people, including whitebaiters, have been led to believe DOC publicity that the scientific reserve is an international showcase for conservation and environmental values and must be protected at all costs.
"In reality it appears it is being allowed to smother and die through inaction by the authorities."
The spokesmen have called on Conservation Minister Eugenie Sage to investigate how her department has allowed the reported level of degradation to occur and to withdraw the designation of "scientific reserve" until it justifies the title.
They say but for the valiant efforts of unpaid local environmental care groups the reserve would be in a worse condition.
Department of Conservation Kapiti Wellington operations manager Jack Mace responds:
The report mentioned by Mr Turver confirms that Waikanae Estuary is a nationally significant wetland habitat — one of very few in the southwestern North Island. More than 60 species of birds breed there, and more wild birds visit it than any other area in the Wellington region.
Development since the 1960s has transformed land around the estuary from coastal wilderness to suburbs.
In the 1970s the Waimeha swamp was drained and whitebait spawning grounds were lost.
Waikanae Estuary Scientific Reserve was established in 1987, with the help of concerned locals, to protect the remaining area. Previous degradation can't be undone, but we can and will protect what's left.
Threats to the delicate coastal environment — and to people's enjoyment of it — do include vehicles on beaches.
" That activity is illegal.
DOC works with dedicated local volunteers on weeding and restoration planting in the reserve, which shows how local people value this place.
DOC will continue to work with other agencies on catchment-based solutions to the problems of sedimentation and runoff which unfortunately afflict many New Zealand estuarine environments.
The difference is this place has the protection many others desperately need.
Kapiti mayor K Gurunathan believes minister should heed call for inquiry into status of 'dying' Waikanae Estuary:
I urge Conservation Minister the Hon Eugenie Sage to respond to the calls by the Kapiti Whitebaiters Network (KWN) and Waikanae Estuary Care Group (WECG) for an inquiry into the degrading ecological state of the estuary.
While the two groups are diametrically opposed to the issue of vehicles being allowed into the environmentally sensitive Waikanae Estuary Scientific Reserve, they are both united in wanting urgent and long-term action to arrest and improve the state of the Estuary.
KWN wants the ban on vehicles to be lifted for them during the fishing season. WECG wants that ban monitored and enforced.
It's well known that previous governments have underfunded DOC. While DOC has done a sterling job in stretching the funding, gaps in service delivery are inevitable and the Waikanae Estuary, I believe, is a victim of this underfunding.
In a letter to the Minister dated August 28, the new chairman of the WECG Robin Gunston said the fragile estuary ecology is under threat from increased recreational use, including people using vehicles, dog walkers and whitebaiters.
He said the low numbers of DOC rangers meant most got away with the damage they caused. He wants the Minister to support the formation of honorary rangers with powers to issue infringement notices.
Mr Gunston has told me he supports any call for an inquiry from the Ministers office.
The call for an inquiry was made in a September 9 letter to the Minister by the spokesperson for the newly-formed Kapiti Whitebaiters Network, Chris Turver.
He has launched a stinging attack on DOC for what he claims has been the historical neglect of the estuary to the point that "it is in fact dying".
He has used the 2015 regional council's scientific field research in the estuary by Wriggle Coastal Management which identified a list of adverse effects on the estuary ecology.
He said DOC was misleading the public about the pristine condition of the estuary, and blaming vehicles and whitebaiters seemed an easier option than the more serious issue of an estuary ecology struggling to survive.
I welcome Mr Turver's call for an inquiry, and support for the Minister to initiate one, but his campaign position to allow vehicles to drive into the ecologically sensitive scientific reserve is an oxymoron when he is also wanting to protect long-term ecology of the Estuary.
