Goat Island monitoring results

By Dr J Floor Anthoni, 2008
To the world, the Goat Island marine reserve in Leigh, New Zealand, is known as an enormous success. But does the marine environment there agree? How does its crayfish population fare and what is known about resident and migrant fish populations? Even though fish are difficult to count, the results show a worrying overall decline

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Visitors to the Goat Island marine reserve delight in the many friendly blue maomao, snapper and others that are never far from the beach. Intensive propaganda campaigns for having more marine reserves have always accentuated the reserve's successes such as more big snapper and legendary densities of crayfish, but the truth is zealously guarded.
The idea of marine reserves grew from the need of marine scientists to have areas in the sea exclusively for doing marine research (studies). The Marine Reserves Act spells this out. But in New Zealand the public was allowed in, on one condition: no taking of any living creature, and this appears to give adequate protection.
In the beginning marine reserves were seen as 'closed areas' where all 'fun' was excluded, like fishing, spearfishing, collecting shellfish, catching crayfish and so on. But later on people discovered that watching the fish was as much fun. They discovered in fact, that feeding them was really appreciated. As marine reserves became more popular, propagandists among whom many marine scientists, began to wildly exaggerate the perceived benefits from marine protected areas (MPA). Read our chapter about marine conservation, the Frequently Asked Questions (FAQ) debunking this unwarranted optimism, the many myths spread by marine reserve advocates, and the chapter explaining why marine reserves disappoint. However, marine reserves are good and necessary for studies, education and recreation - in short for human needs.

Marine reserves disappoint because mysteriously they are losing fish rather than gaining them, even though we are quite certain that this was not caused by fishing, as even unfished species are disappearing at similar rates. Of course the Goat Island marine reserve is not exempted from degradation, as shown by all monitoring conducted here. Note however, that scientists focused mainly on the commercial species crayfish, snapper and blue cod. Much of what disappeared must therefore be reconstructed from anecdotal evidence, which is the most important part of this chapter because it is the only place where this has been documented.

This chapter about monitoring the Goat Island marine reserve begins with a timeline chronicling the major events affecting resident populations. Then it looks at the various populations that collapsed one after the other.

As one can see, the marine reserve has suffered a major decline in nearly all species. To understand why and how, please read the decay section.

Because we have been living close to the Goat Island marine reserve since 1976, we have been able to dive its entire range regularly, thereby observing the many changes happening over time. The timeline presented here should be read in conjunction with the one shown in our habitat survey of 1993.

Kelpbed death
In November 1992 we warned the scientists at the Leigh Marine Laboratory that the plankton blooms were so dense that kelp would soon die. They laughed. In December we told the same scientists that the kelp had died, over the entire depth profile, except in the sheltered shallows. They laughed again. After the university holiday, end January 1993, we told them that the entire kelp forest had disappeared. They confirmed this and wondered why. They could not understand that there had been some shallow damage due to cyclone Oli and entirely separately, deep damage due to dense plankton blooms. We did a preliminary survey and once able to go out (in winter, brrr), did our complete habitat survey inside and outside the Hauraki Gulf..

Our survey established the extent of the plankton blooms, and we discovered that there had also been one the year before in 1991/92.

extent of kelpbed death Leigh
Our habitat survey of 1993 was able to locate the extent of the kelpbed loss due to dense plankton blooms, both for 1993 and the year before. Note the thin dashes, the many transect dives done in winter.
kelp death Goat Island
1993. Cyclone Oli sheared the crowns off the stalks and pulverised them as the kelp had been dead for months. Not a trace of the kelp canopy was found.
very sick kelp
2005. Observant visitors to the marine reserve will notice that the kelp there is no longer slimy, as healthy plants would be. Many are in fact already dead, looking like this plant. In 2009 most kelp plants were seriously ill and dying.
very sick stalked kelp
2005. These decaying kelp plants have lost all their food value, reason perhaps why butterfish that feed on kelp, declined precipitously. Notice some butterfish bit holes in the kelp fronds.
large kelp wash-up on Goat Island beach
2009. Insignificant storms now cause major wash-ups of broken kelp that does not belong in the urchin barrens (storm barrens), resulting in wastes decaying in the shallows, and like a rotten apple in the fruit bowl, affecting all species living here, also those in the intertidal. This is food that should have been eaten!

Urchin deaths
Over a period of several years, barren surfaces became covered in a brown slime, later identified as a benthic (bottom-) dinoflagellate of the Ostreopsis genus, which produce a poison identified as Flavotoxin, which is very poisonous to those who eat it. As the sea urchins and other grazers diminished in numbers, they left their barren areas insufficiently grazed, thereby allowing the recovering kelp forest to invade and more Ostreopsis to establish itself. This began slowly in 1996, and more suddenly in 1998/99. From personal observations, the disappearance of urchin barrens began in the areas that had previously lost their kelp forest, but later everywhere along the whole east coast (2007).
Scientists wrongly concluded that the urchin barrens disappeared because potential predators of urchins, crayfish and snapper had grown large and numerous enough to eradicate the urchin population. They called this top-down trophic cascades. There are quite a number of hard facts that refute this hypothesis, as explained in our rebuttal of their science (important reading). Sadly, the scientific literature is awash with references to this shoddy work from the University of Auckland, that has never been recalled. Now our children are learning this at school, thanks to the Department of Conservation's extensive marine reserves propaganda, which will also never be recalled.
disappeared urchin barrens Leigh
1993. Urchin barrens disappeared in two marine reserves (red), Goat Island and Tawharanui. Scientists wrongly concluded that this was a marine reserves effect and didn't look at nearby areas (yellow) outside marine reserves where it also happened.
aerial Goat Island marine reserve
This aerial photo was taken in April 1999, showing the main barren area of the Goat Island marine reserve. Notice how the kelp is beginning to invade, but most of the invasion happened suddenly a year later. Scientists maintain that it was a gradual process that began before 1980, which is proved untrue by this photo.
ostreopsis on pink turf coralline alga
2002. A patch of pink turf (a turfing coralline alga) heavily infested with brown Ostreopsis slime. Notice that there are no grazers of any kind.
sea urchin dies from eating Ostreopsis
2003. A common green urchin (Evechinus chloroticus) is dying after grazing a swath through Ostreopsis slime.

spiny lobster Jasus edwardsi at Goat Island population collapseCrayfish (Jasus edwardsii) is being monitored on an irregular basis, particularly once their numbers appeared to even out at a maximum of around 30 animals per 500 square metres. In 1998 we noticed that the usual moults were absent in the shallows where we conduct guided snorkel dives for schools. A preliminary survey by ourselves showed that many had indeed disappeared. We informed the scientists at the Marine Laboratory but they ridiculed us, saying that there were two scientific groups working with crayfish and that everything was okay. In April after the school visits, we did a proper survey and estimated that 75% of all crayfish had disappeared. Again we informed the Laboratory but again we were met with ridicule. After all, two groups were doing crayfish research at the time and they should have noticed! Then in 2001 they did the planned crayfish survey (paid for by DOC) which showed that 5 out of 6 crayfish had indeed disappeared. The graph on right shows how crayfish became much more numerous than outside and how the population collapsed between 1995 and 2002 (in 1998 to be precise). We were being proved right again.
The upswing after 2001 was hailed as 'marine reserve recovery', expecting densities to recover fully. However, the 2014 crayfish survey (dashed green after 2004) showed continuing decline to pre-protection levels [Haggitt & Freeman 2014]. Similar bad news came from other protected areas, and of course the blame was laid on fishermen, what else?
Read the article in a local newspaper, (12 Sept 2016): Crayfish decline continues to impact marine reserve. In this article, marine scientists from Leigh are pitched against commercial fishermen of Leigh. Scientists allege that overfishing outside affects the stocks inside the reserve. However, that would refute the dogma that marine reserves "serve as an insurance policy against overfishing". And actual  landings although showing a 5-10% dip  in 2000-2003, refute "excessive overfishing" resembling the marine reserve crash (see graph below).  Commercial fishermen maintain that stock management "is well in hand" and that occasional dips in landings can be expected. 
This graph obtained from fish.govt.nz shows yearly landings and total allowable catch from 1990-2008. Although catches fluctuate by 10% occasionally, on the whole, fishermen are able to land what they are allowed to catch. The dip in 2000-2003 in no way resembles the marine reserve stock collapse.

Note that the crayfish population outside is heavily influenced by the marine reserve in what is called fishing displacement. In other words, by closing a good crayfish habitat off, it increases the fishing pressure outside. Although the positive difference between inside and outside is hailed as a benefit, it is in fact a serious liability. It so happens that in the Leigh area, two marine reserves were created on good crayfish habitat, leaving a small area of no more than 30% inbetween, now heavily overfished. Consider this blatantly ignorant statement by a marine scientist (Haggitt & Kelly 2004): "the 5 km long Cape Rodney to Okakari Point Marine Reserve [Goat Island] contains the equivalent of lobsters from 75 km of fished Leigh coastline". Such is the disgraceful effect of displaced fisheries.

Reader please note that best management would be to fish at higher stock levels, which is also more profitable.
Note also that during our Hauraki Gulf marine survey in 1993, we remarked:"Crayfish has become one of the rarest organisms in the Gulf. Very few were encountered. We found more boat anchors than crayfish and also more of the rare giant boarfish!" link.

crayfish city Jasus edwardsi congregation
1996: crayfish 'cities' like this small one were once common but disappeared after 1998. They were in fact so common that I postponed taking good photos of them. Now this poor image from 1996 is all that remains and it appears nobody else has a better image.
crayfish and urchin test
2003: this was once a crayfish 'city' off Tabletop Rock, with some 50 animals in it and another 70-80 outside the frame. Now it houses a single bug. Notice the sediment everywhere and one consumed sea urchin in the foreground.
Goat Island road erosion
Aug 1997: road side collapse
August 1997: the Goat Island road was widened and hardened but its verges and banks were not stabilised, resulting in slips and clips as shown here. During the winter of 1997 hundreds of tonnes of mud washed into the marine reserve. The sea was muddy for many months. Was this the reason the crayfish left the marine reserve?

It is interesting to note that the thousands of visitors to the marine reserve did nothing about it, among whom:

  • The University of Auckland's Leigh Marine Laboratory whose research depends on the health of the marine reserve.
  • The Department of Conservation who is responsible for the health of the marine reserve and any substances deposited there.
  • The Rodney District Council who signed off the road works, knowing full well that they did not conform to standards, and that the road banks were unstable. Nothing was done afterwards either. Notice the damage to the fence which the owner needed to repair himself. Council would not comply.
Such is our total apathy towards the environment (sigh).

Fish are notoriously difficult to count reliably. Scientists do this by studying an area and counting the fishes in that area. Usually an area of 50x5m is covered by laying out a 50m tape and swimming out along one side and back along the other side, observing a swath of 2.5m each side of the tape. Sometimes divers are followed by curious fish, and conversely, shy fish may make themselves invisible upon arrival of the diver. But most frustrating is that fish do not occur evenly spread, but rather in groups. For their studies, scientists invariably avoid counting pelagic and semi-pelagic fish like blue maomao and sweep, and also the hidden ones such as triplefins.

fish populations Goat Island marine reserveThe marine reserve was gazetted in 1975 but in 1977 the reserve was officially opened, signs were placed and policing began. So 1977 is the effective date of the establishment of the marine reserve. From its early days we have the fish counts performed by Dr Tony Ayling, shown here. The only fish species threatened at the time by line fishing were snapper and blue cod. Threatened by spearfishing were in addition red moki and butterfish (Odax pullus) (not counted). Surprisingly, snapper did not recover, blue cod somewhat and red moki a lot. Red moki (Cheilodactylus spectabilis) is a resident fish that stays in an area near a good sleeping hole. Snapper (Pagrus auratus) is highly migrant. Spotty (Notolabrus celidotus) belongs particularly to sheltered areas (inside harbours) with poor water quality where they abound.

Red moki hole Cheilodactylus spectabilis
Red Moki have become the reserve's most successful fish species because they do not migrate but rather stay on the rocky shore near sleeping holes where they congregate. The fish also grow old and feed from invertebrates hiding in coralline turf. All they need is found on the rocky reef. They are also sociable rather than territorially competitive. About 20 fish bed down in this sheltered Moki Hole.
mature snapper Pagrus auratus
Snapper are mainly migratory, occasionally visiting the reserve, even though some may stay for several years. For them the island is an oasis adjacent to a 40km stretch of beach and a very large open sandy area. From their shelter they forage far and wide. For this reason, the Goat Island marine reserve is not typical of the coast.

In 1988 another fish count was done by Russell Cole (Cole et al. 1990 ) who compared fish populations after 10 years of protection. He used Ayling's data for comparison. The table below gives the details for several study areas in shallow water (shallow broken rock habitat) and on the urchin barrens (rock flats).

fish counts Goat Island marine reserve

From the table above it can be seen that variability was extremely high but by adding the totals across each habitat, a picture emerges that is rather consistent. The table on right shows relative population gains (>1.0) and losses (<1.0) from a starting population of 1.00 for each species, calculated from the table above. As one can see, only spotties are the clean winners. Note that spotties are not a popular angling or spearing fish, and have never been threatened in the reserve area. Its increase to 236% (+1.36) could be attributed to a deterioration in water quality, which also explains the losses in the other species.
Quite contradictory to common perception, snappers did not increase while goatfish (Upeneichthys lineatus), blue cod (Parapercis colias) and parore (Girella tricuspidata) suffered heavy losses, diminishing four-fold (-0.8). This agrees with anecdotal observations. Note that silver drummer (Kyphosus sydneyanus) and marblefish (Aplodactylus arctidens) occur in such low numbers that their losses may not be real. However, anecdotal observations have seen a substantial decrease in the herbivores parore, silver drummer, butterfish and marblefish.
The table above leaves out the raw data for fish counts over the kelp forest but the publication shows bar charts for 7 of the above species, with goatfish and spotty more common outside the reserve whereas snapper and leatherjacket are less common outside. Overall there is about 40% less fish outside the marine reserve (0.57, 0.6, 0.6).
Independent counts for snapper show that small snapper (10-20cm) are far more common outside the reserve whereas medium-sized fish (20-30cm) are equal in numbers and large fish (30-40cm) far more common inside the reserve.
shallows rock flats
spotty female -0.10 +1.36
spotty male -0.30 +0.32
snapper -0.70 -0.76
goatfish -0.78 -0.63
leatherjacket -0.56 -0.02
blue cod -0.84 -0.13
red moki -0.76 +0.97
parore -0.80
silver drummer -0.50
marblefish -0.82
Relative gains/losses for most common fish species between 1978 and 1988. Variability was high.
Source Cole et al. 1990.

Anecdotal evidence
Because scientists are too busy following their own interests, the overall health of the marine reserve has not been monitored, and for this we must rely entirely on anecdotal observations. We were frequent visitors to the reserve due to our school programmes and also because of a passion for underwater cinematography with which we documented most of our observations. Later we had to catch specimens for the Seafriends aquariums (outside the reserve) which furthered our observations. We have placed these more or less in chronological order.

Many publications appeared either in scientific journals or as reports to the Department of Conservation, or in the form of master of science and PhD studies, and many are therefore difficult to access. 


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