The mortalities were unusual and upsetting but the fisher was fishing legally in an area where he has done so for many years without such an incident.

He did not have an observer on board but promptly reported the captures, consistent with fisheries law.

Fisheries Inshore New Zealand chief executive Dr Jeremy Helson in turn directly informed Fisheries Minister Stuart Nash.

A review of the threat management plan for Hector’s and the critically endangered Maui dolphins which have been in place since 2008 would be accelerated, Nash and Conservation Minister Eugenie Sage confirmed.

A science-based review is supported by the industry.

Nash agreed it was important to take an evidence-based approach and weigh up the economic and social costs of a wider set net ban on the 300 fishers who used nets.

A range of options includes a total set net ban.

Sage took a harder line, going back 45 years and drawing in Maui dolphins.

She said official records showed 188 Hector’s and Maui dolphins are known to have been killed in nets in that period but felt incidents “were almost certainly under-reported and the real number was much higher”.

“Having a serious look at how to best phase out these near invisible and deadly monofilament gill nets is long overdue. Fishers can use other methods to catch target species such as butterfish, mullet, rig and school shark.”

That is not in fact the case with species such as reef dwelling butterfish, which are not trawled or potted and do not take baits.

The seafood industry is committed to reducing its impact on the marine environment.

But just as farming impacts on land, fishing activities do in some cases accidentally capture relatively small numbers of endangered species.

The fisher in this instance has voluntarily elected to stop fishing in the area six nautical miles north of the peninsula where the five Hector’s were caught.

Also last month, four set netters in the vicinity of Codfish Island off the west coast of Stewart Island elected to suspend their activity within four nautical miles of the remote island until a threat management plan determined risks and any appropriate conservation measures for the yellow eyed penguin (hoiho) population was completed.

They advised ministers Nash and Sage on February 8 they “reject the notion that commercial set netting is responsible for the plight of the penguin population but have resolved to take the action as a good faith gesture”.

The Ministry for Primary Industries’ response to the Hector’s incident was measured, putting the “unfortunate and unusual incident”  into context.

“Set netting is permitted in the area where the incident occurred and the event was reported to MPI by the fisher,” it confirmed.

MPI also repeated the good news on the dolphins’ population – the most recent comprehensive surveys undertaken between 2012 and 2015 in the three main South Island populations revealed numbers were twice those previously thought.

“The population is now estimated to be approximately 15,000, whereas the previously published estimation was 7000,” MPI said.

This fact does not suit the environmental activists’ narrative so is accordingly ignored.

Neither did it feature in news reports.

About 15,000 square kilometres of inshore waters are already closed to set netting around the North and South islands in areas deemed to pose the greatest risk to the dolphins.