Blue Moki

Story by Jen Howe

Whilst walking along the coast within the Taputeranga Reserve, you may have spotted a blue moki or two painted along the pathway or on the shirts and hoodies of the Coast Watch volunteers.

 moki-stencil-1

Original drawing of the stencil (Jen Howe)

The real blue moki, Latridopsis ciliaris, is a species of the trumpeter family and is native to the south-western Pacific Ocean around New Zealand, and sometimes also occurs off the south east coast of Australia. In NZ it is more commonly found south of the East Cape, probably due to their migration behaviour. Annually, during the winter, adults travel along the east coast of NZ up to the only known spawning ground off Gisborne before travelling south again. The eggs and larvae are carried away from the spawning ground towards the south by the East Cape Current. They live their larval life for 8-12 months in the water column before settling onto shallow reefs when reaching about 10 cm in length. Here, they live on small crustaceans which they find amongst the weed. They remain in the reef shallows for another 4-5 years until they reach maturity and a length of about 40 cm. At this time the blue moki moves further offshore to join the schools of adult fish where they can grow to 80 cm and live for over 30 years, though most are commercially taken when they are between 40-60 cm long. The oldest blue moki recorded was 43 years old.

The blue moki is a handsome fish with an elliptical silhouette ending with big, fleshy lips. It is a blue-grey colour along the top, often with dark or lighter bands, and fades to silver below.  Juveniles are often seen by divers and snorkelers, swimming among the weeds on the rocky reef or over the sandy bottom.

 blue-moki-elsdon-pipe-jh

Blue moki amongst weed at Elsdon Pipe – Photo: Jen Howe

Unfortunately for the blue moki they are good to eat and are easy to find. The juveniles are recommended as a “great fish for new spear-fishers to start on” as they are found in shallow waters swimming slowly in the currents, and don’t scare easily. A diver or a fisherman may take up to twenty fish per day. The adults are an easy target for commercial fishers too as they move in large schools. They were introduced to the Quota Management System (QMS) in the mid-1990s, since when their numbers have declined.

As blue moki are highly targeted by fishers, and occur in “relatively high abundance compared to other targeted fish species”, it was recommended that it be monitored as a “priority indicator species” when establishing the Taputeranga Marine Reserve. The reserve was established in 2008 but a baseline survey, including one for blue moki, was carried out in 2001 by Anjali Pande and Jonathan Gardner. Blue moki was an interesting fish to use as it is so mobile. After all, fish are not able to tell where the Reserve boundaries are. Would creating a relatively small reserve have any effect on numbers of blue moki within the reserve? Would protecting a heavily harvested species show quick or slow signs of recovery within the protected area? Daniela Diaz-Guisado’s research between 2011-2012, found that blue moki was the only highly mobile species to show signs of recovery from the Reserve’s protection. More time may be needed to gauge whether protection will also help other mobile, heavily fished species.

Next time when you’re in the water, have a look for the glint of blue moki and know that the Reserve has made a difference offering this species protection from the pressure of fishing.

Bibliography:

Effects of Marine Reserve Protection on Adjacent Non-Protected Population in New Zealand (2014) – Daniela Diaz-Guisado
A Status Report on the Biological and Physical Information for Wellington’s South Coast with Monitoring Recommendations for the Taputeranga Marine Reserve prepared for DOC (2008) – Tyler Eddy, Jonathan Gardner and James Bell
Evaluating Biological Change in New Zealand Marine Reserves (2001) – Anjali Pande
Wikipedia
Wildblue.co.nz
www.forestandbird.org.nz