The Amazing Poor Knights - Now Totally Protected, And Showing It!
As published in Dive New Zealand magazine, February-March 2006 issue
The Poor Knights Islands have always been an awe-inspiring place, both above and below water. Recognised early by dive pioneers as being very special, a succession of world famous divers have proclaimed the Knights to be right up there amongst the top dive sites of the world. For example, in the late 1980’s Jacques Cousteau and the Calypso crew proclaimed the Poor Knights as one of the world’s top 10 dive sites. And that was before it was fully protected.
The history of moves to protect the Poor Knights as a Marine Reserve is covered elsewhere in this issue. Suffice to say here that for many years only two small parts of the Poor Knights were totally protected from fishing, while limited recreational fishing was allowed in most of the Poor Knights waters. That anomaly was finally corrected in 1998 when full protection was given to the marine life of the Poor Knights, around the whole island group out to 800 metres offshore.
That started a revolution.
The fish noticed.
Snapper arrived in their droves.
Previously a rare sight underwater, within two years snapper numbers increased something like 16 times. Happy to live in an area where their mates were not being hauled out on a fishing line, the snapper settled down to a long and happy life in the now tranquil waters of the Poor Knights Islands. No longer did they have to endure the terrifying vibrations sent out by fish struggling for their lives on the end of a line - endure or flee, or even keep away. Now at last they had a safe haven where they could live in peace, grow old gracefully, and restore the normal social behaviour patterns totally disrupted in the outside world.
If you visit the Poor Knights now in summer, as soon as the boat stops you will see snapper milling around beneath the surface - not only beneath the boat but also generally in open water near the islands. And when you get into the water and swim to the shore, the snapper are just going nutz! Crowding up and down the kelp-covered cliffs will be dozens of snapper, mostly good "pan-sized" fish, but with the occasional giant. Larger ones will become more common as the population matures.
The snapper don't come right up to you as they do at the Goat Island Marine Reserve, where they are still slowly "un-learning" to associate divers with food, following many years of illegal fish feeding by well-meaning visitors. But at the Knights they tend to remain a little aloof, just interacting among themselves and largely ignoring divers in what we can assume is more natural behaviour.
Research by Auckland University Leigh Marine Laboratory staff and students documented the recovery of snapper populations at the Poor Knights following their total protection. Using a technique called baited underwater video (BUV) they were able to show the dramatic increase in snapper following protection. Using the same technique at the open-fishing Mokohinau Islands and Cape Brett, the comparison was staggering. While snapper numbers remained low at the Mokes and Cape Brett, numbers rapidly increased over two years at the Poor Knights.
Baited underwater video uses a small video camera mounted on a frame looking down to a standard-sized horizontal triangle at the base. A standardised bait box containing four pilchards is attached to the base and the scene recorded for half an hour as fish are attracted to the bait. The maximum number of fish seen in one video frame in the half hour is the "number" for that drop. Individual fish lengths can be measured against a scale on the base. Usually two or three replicate counts are done at each site, and about 30 sites would be used to characterise an area. This way comparative counts for different areas can be used to give a relative abundance of snapper. The system is often deployed inside and outside marine reserves for comparison.
The BUV system simulates what a fisherman would do to find a good fishing spot - if he got few bites in one area he would move elsewhere until he got lots of bites indicating a good fish population.
Another spectacular change in the past few years as a result of total protection is the amazing recovery of pink maomao. I have not seen so many pink maomao at the Knights for many years, if ever. In December cruising along the cliffs there were frequent schools of pink maomao visible close to the surface. Schools of trevally - another recovery indicator - feeding on krill were often accompanied by blue maomao, with hundreds of pink maomao schooling below them. Often below the pinkies were dozens of snapper and the occasional kingfish. When the pinkies were not out in the open, they crowded into the archways and caves. I have never seen Northern Arch so stuffed wall to wall with pinkies!
Reduced to almost zero prior to total protection, golden snapper are now making a come-back. Historically they formed large schools in places like Northern Arch. There is now a school of around 200 fish hanging under the overhang in the middle of the Arch, reminiscent of the sights of the mid 1970's.
But to me, the most exciting development is that we might at last be seeing a return of hapuku to the Poor Knights. During the last year there have been at least three sightings of small hapuku in shallow water in different areas at the Knights. Just small fish, only 60 to 70 centimetres long, but it is a start. Let's hope they follow the snapper's lead and decide to hang around and grow big!
I last saw large hapuku at the Poor Knights in the early 1970's. Prior to that, on the shortest day in 1969 I was on a trip to the Pinnacles when one of the divers discovered the Hapuku Slot - a sloping tunnel formed by a big slab of rock leaning against a cliff in deep water. There were 30 hapuku milling around over the top of the rock. I dived there in the afternoon when all the puka were inside the slot. One huge puka, about 90 kilos and looking like a cow, broke off from the group and charged out to see me, stopping barely half a metre away and waving its jaw up and down!
Hapuku are now virtually extinct in diving depths, having been grossly over fished by commercial and recreational fishermen. Historically they were a common shallow water reef fish all around our coasts and were caught by hand-lines off the rocks. Nowadays everyone considers them a deep water fish. That is the only place any are left! Not much use to divers. They had the potential for spectacular interactions like you can have with the large spotted black grouper at the Kermadec Islands.
It is not likely there will again be large hapuku in diving depths in my lifetime. But with signs of a return of juvenile hapuku to the Poor Knights, and with the large marine reserve planned for Great Barrier Island which includes lots of really good deep reef hapuku habitat, perhaps there is a chance my kids or their kids may be able to see schools of large hapuku like I experienced in the 1960's. With present fisheries management policies, large marine reserves are the only chance hapuku have of some sort of recovery.