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
Introduction 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
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
Timeline 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.
1975 - the marine reserve was gazetted by an Act of Parliament, which was
the official act in its creation
1977 - the marine reserve was officially opened and not long thereafter
signs put up.
1978 - first fish survey done by Tony Ayling. Also crayfish surveys begin.
1983 - a year of major mass fish mortalities noticed by us, extending to
the Poor Knights islands and further north. Scallops die from being suffocated
by plankton organisms. Giant heart urchin died for the same reasons.
1986 - cyclone Bola rains out over New Zealand, causing mud storms and
1988 - second fish survey by Russell Cole
1992 - another year of mass
fish mortalities observed by us. Massive plankton
blooms in October, documented by the Leigh Laboratory. In December
the kelp forest died for lack of light.
1993 - early January, cyclone Oli removed the entire kelp forest and no
trace was found as the kelp crowns had the consistency of soaked paper.
The Marine Lab did a half-hearted investigation (Babcock & Cole 1993),
reason why we did ours,
resulting in some astounding discoveries about the extent of the plankton
blooms, urchin habitats, habitat zoning and more.
1995/96 - a poisonous matting dinoflagellate (brown slime) later identified
as an Ostreopsis species, killed anything that grazed on it, particularly
sea urchins. As the urchins disappeared, the stalked kelp moved in, thereby
turning the barren zones into kelp forest. See our large rebuttal
of Babcock's top-down trophic cascades hypothesis (snappers eat
urchins, urchins eat kelp thus more snappers means more kelp).
1998 - the Goat Island Road is widened, resulting in hundreds of tonnes
of mud washed into the reserve. Perhaps by coincidence, the crayfish walked
out, leaving 15% in the reserve.
2000 - a new crayfish survey finds that 5 out of 6 crayfish disappeared
from the marine reserve.
2004 - the latest crayfish survey finds that crayfish numbers are increasing
2008/09 - Ostreopsis dinoflagellate slime has invaded the intertidal
rocky shore, leaving few survivors.
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.
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.
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
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.
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.
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
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.
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.
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.
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.
2003. A common green urchin (Evechinus chloroticus)
is dying after grazing a swath through Ostreopsis slime.
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.
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
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
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.
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.
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
Such is our total apathy towards the environment (sigh).
Fish 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.
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
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
auratus) is highly migrant. Spotty (Notolabrus celidotus) belongs
particularly to sheltered areas (inside harbours) with poor water quality
where they abound.
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.
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).
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
gains/losses for most common fish species between 1978 and 1988. Variability
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.
Once visitors to the marine reserve began breaking sea urchins to feed
the fishes, as an immediate response various large seaweeds (macroalgae)
began occupying the bare rocks near the beach. These were mainly the featherweed
In the beginning, Shag Rock was topped by lush cartilage weed (Xiphophora
chondrophylla) with a band of red fretsaw weed (Vidalia colensoi,
Osmundaria c.). In the shallows one frequently encountered the green
grapeweed (Caulerpa geminata). These have all disappeared, taking
a lot of colour out of the shallows.
In the beginning there were multitudes of pink golfball sponges (Tethya
ingalli) and yellow nipple sponges (Polymastia croceus) with
the occasional orange nipple sponge (Polymastia granulosa). On vertical
rock faces, sheltered from sunlight one would find the hydroid tree (Solanderia
sp). All these species have disappeared although the cartilage weed
came back a little in 2009 which also turned out to be a good recruitment
year for snapper.
In the middle of the Goat Island Channel one could find venus cockles (Venerupis
largillierti?) and numerous eleven-armed stars (Coscinasterias calamaria)
predating on these, as well as numerous sand octopus (Octopus gibbsi).
In fact, a visiting scientist (Dr Robin Crump) was studying this community.
On the shallow barren rock flats shown in the aerial
photo above lived a large community (acres) of brown bearded mussels
areolatus) predated upon by large numbers of eleven-armed prickly stars
calamaria). Divers often broke these mussels to feed the fishes. Now
none are left and the whole habitat has disappeared.
Where the marine reserve begins on its western flank, is not far away from
a special habitat that I call the 'shell trap'. During storms shells are
washed up on the Pakiri Beach, and usually end up on its eastern rocky
shore where shells are trapped in gullies and deep sand habitat bordering
the rocky shore. As a result one could find very large patches of fan mussels
zelandica), a very large horse mussel that cements its byssus threads
to the sand, just peeping out above it. Their populations were so dense
that they were pushing one another out of the sand as they grew. Sand octopi
gibbsi) were then ready to eat them. After Cyclone Bola in 1986, this
whole area was covered in a thick sticky mud cake that took 4 years to
'dissolve'. The mussels never returned.
In 1976 the numbers of blue maomao (Scorpis violaceus) were legendary
and we could see large patches of several acres each, of iridescent blue
frothing in the distance. Gradually blue maomao became less numerous, also
killed in large numbers in 1992, 2001. During the times the public was
feeding them, one could find several hundred in the Goat Island channel
but in 2009 it was almost deserted. We noticed during the whole period
1990-2000 that the fish remained young and never grew any older than 3-4
years. Also on the Poor Knights the deep blue large 10-year old blue maomao
violaceus) had disappeared. In 2009 I did not see any during an entire
dive at the deep side of Goat Island, where they normally occur. The large
trevallies also became very rare.
With the blue maomao, also other plankton feeding fish disappeared like
trevally (Psudocaranx dentex), jack mackerel (Trachurus novaezelandiae),
koheru (Decapterus koheru) and most conspicuously the huge kahawai
schools (Arripis trutta) frothing the water as they swam past. We
mentioned the demise of the demoiselles before. Note that these species
still occur in very low numbers.
In the early days one would find numerous baby demoiselles (Chromis
dispilus) in Goat Island Channel, often hiding between the spines of
sea urchins. Over the barrens off the west point of the island at Pempheris
Point, one would find numerous males nesting while females were hovering
in mid water. This all disappeared by 1993.
Since 1996 the common sea urchin (Evechinus chloroticus) has been
decimated in numbers and the purple urchin (Centrostephanus rodgersi)
has become very rare indeed, as also the black angelfish (Parma alboscapularis).
The longfinned triplefin (Ruanoho decemdigitatus) was once reasonably
common if one knew where to look. Now it has almost completely disappeared.
Compare this with their abundance in the Hahei marine reserve.
Large long-snouted pipefish (Stigmatopora sp.) and even seahorses
abdominalis) were encountered frequently but they disappeared by 1990.
Occasionally one can still encounter a smooth pipefish (Stigmatopora
macropterygia) but they too have become very rare. It is fair to say
that the seahorse has become extinct in our area, including the local estuaries
as far as Auckland.
In 2009 most if not all of the kelp was seriously ill and dying. The new
recruits didn't fare much better and barren areas began to reappear.
In the early 1980s we noticed the brown Ostreopsis slime in autumn
in sheltered places but although killing an urchin here and there, it never
became a serious threat. By 1992 Ostreopsis became a major threat,
not only here but all along the East Coast, not exempting remote islands
either. (Cavallis, Poor Knights, Great Barrier, Little Barrier, Mercuries,
In 2007/08 there was a mysterious influx of the schooling triplefin (Obliquichthys
mariannae) which was never present before. In 2009 we noticed that
their numbers had declined steeply.
In 2008/09 we discovered that Ostreopsis has done its kill in the
intertidal rocky shore of the local reef flats, such as Echinoderm Reef.
does not survive above water, and because of this has selectively killed
the catseye snail (Turbo smaragdus), very noticeable because these
snails can become old and large. The following species also disappeared
almost completely: all species of brittle star, all triplefins, rockfish,
all sea hares and even porcelain crabs. Our findings were confirmed by
Dr Bill Ballantine.
Publications 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.
Russell C Babcock & Russ G Cole ( Jan-May 1993):
extent of die-back of the kelp Ecklonia radiata in the Cape Rodney to Okakari
Pt Marine Reserve. Advice to the Department of Conservation,
June 1993 University of Auckland Leigh Marine Laboratory
Cole Russell G , Tony M Ayling, Robert G Creese 1990: Effects
of marine reserve protection at Goat Island, northern New Zealand.
New Zealand Journal of Marine and Freshwater Research, 1990, Vol. 24:197-210.