KEY POINTS:
The fate of the Maui's dolphin hangs in the ecological balance - of that there is no doubt.
But there is plenty of dispute over what can and should be done to try to save it. And plenty of doubt that it can be saved at all.
The impact on commercial and amateur fishers may come through added restrictions on the use of nets to complement an existing ban on set-netting in the area from Baileys Beach to New Plymouth.
A meeting on the use of nets on the Manukau will be held at the Titirangi RSA on Monday night at 7pm as the Department of Conservation and Ministry of Fisheries consult interested parties before preparing a "threat management plan" to try to save the species.
Forest and Bird, the World Wildlife Fund and other groups continue to push for total net bans. Set-netting is already banned along the west coast from Manganui Bluff north of Dargaville to Pariokariwi Pt north of New Plymouth, as well as in the mouth of the Manukau.
DoC has spent tens of thousands of dollars on aerial recording of the endangered dolphins and on sea trips to count them, to the point where it lists the number of dolphins as a very exact 111. Sonar recording has been employed to try to prove the dolphins do enter the harbour and thus gain evidence to extend the net ban.
People who have lived on the harbour's edge and fished the Manukau for many years say they have never seen one in the discoloured, colder and greener water inside the mouth - common and bottlenose dolphins yes, Maui's no.
But an Otago University study that has planted listening pods around the Manukau may prove them wrong.
Associate Professor of Zoology Liz Slooten said acoustic data loggers have been in the Manukau for 2 1/2 years. Maui's dolphins produce only high frequency sound whereas others produce a mix of high and low frequencies.
"Maui's dolphins are definitely using the Manukau Harbour on a regular basis and they are going further up it than the area covered by the net ban," Slooten said.
A data logger was recently introduced to the Kaipara and the university plans to put them in other west coast harbours.
Four Maui's deaths have been recorded this year, none apparently from nets.
A total of 309 deaths of Maui's and Hector's dolphins combined have been recorded since 1989. Of those, DoC says 42 per cent were "confirmed or probably as a result of fishing interaction". Two per cent were confirmed to have died of natural causes; in 56 per cent cause of death is unknown, often because of decomposition.
Some believe the low number of dolphins and the lessening of genetic diversity mean they are goners already, destined to fall victim to an increasing number of inbred diseases.
Females do not mature until they are 7 to 9 years old and they produce just one calf every two to four years.
* The Huia Fishing Club ended what has been a very ordinary season's fishing with what is possibly the best catch on the Manukau this year. At its last contest for 2006-07, a 10.57kg kingfish was leading the board until local Anna Brockhurst returned to base with a 27kg kingie caught on a 10kg line in what the locals refer to as kingfish alley. The fish took a dead bait "swimming" in the heavy current.
Several other anglers were broken off by big kings. Other species were scarce: 13 kahawai landed and one 1.12kg snapper. Flounder are plentiful in the Manukau.
Will the easterly blow off Northland keep the warm water and the fish in? That was what anglers from the Far North to Whitianga were wondering this week, as high winds and swells put a temporary stop to what has been an extended gamefishing season.
Broadbill and marlin were taken from the Poor Knights up to Cape Brett again at the weekend and early this week, large schools of squid attracting them close to the coast.
Big snapper are abundant in the Hauraki Gulf and Firth of Thames between the 40-50m mark.
