Marine Reserves
paradise won or lost?
by Dr Floor Anthoni (2007)
www.seafriends.org.nz/indepth/reserves.htm
in-depth logo Floor Anthoni
Compared to the land, the sea is a place very much left alone, apart from fishing and a few other impacts. We don't live in the sea, plough its soil, burn its forest, build houses, cities and roads there, nor do we let introduced pests roam free. So if only we stopped fishing, the sea would return to something close to a paradise. This concept of marine conservation by means of total protection, no-take marine reserves, would have worked splendidly if only the situation were ideal. Unfortunately a new threat, that of degradation, has loomed very large. Let's examine the marine reserve concept in depth to learn more about marine protection and why it fails.

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For corrections and suggestions, e-mail the author.
[in-depth index] [home]--Rev 20070828,


The marine reserve concept

The marine reserve concept stems from the early days of marine science, when scientists needed selected areas in the sea to do marine research. Such places were necessary because were people to catch fish, shellfish and lobsters, they would almost certainly upset any scientific studies of these marine creatures. But exploitation could interfere in other ways too, like upsetting the balance of the environment.

 
In the early 1960s, New Zealand had only two marine laboratories, the oldest at Dunedin (Portobello Marine Laboratory) and the marine laboratory at Leigh. Later, Wellington would get its own (at Island Bay) and to some degree Christchurch too. The idea of marine conservation was pushed strongly from the Leigh Marine Laboratory of the University of Auckland, which resulted in the Marine Reserves Act of 1971 (MRA 1971), rather than an amendment to the existing Fisheries Act. The first marine reserve at Goat Island, adjacent to the Leigh Marine Laboratory, was gazetted in 1975. The MRA was amended in 1977 and 1996 (MRA 1996). In 2002 an attempt was made to make it more general while applying to the entire Exclusive Economic Zone (EEZ) with a focus on biodiversity rather than research (the marine reserves bill 2002, now in limbo). This attempt failed because it was so poorly done and it did not address the problems while also massively duplicating existing legislation. Today it has become clear that it would have been much better to abolish the Marine Reserves Act altogether, and to accommodate all marine protection under the Fisheries Act. The problem of the MRA and the proposed Bill is that it provides only for complete no-take protection, ignoring all other forms of protection. The Fisheries Act on the other hand, provides for all kinds of marine protection, including full no-take protection forever (marine reserves), and it involves the stakeholders, the fishermen. Remember that marine reserves are all about fishing - no fishing.

The marine reserve concept grew steadily from necessary protection for doing marine research, to that of saving the sea, and it went even much further than that, to protecting biodiversity and other fantasies about their possible but unproved benefits. One does not need to be very smart to understand, that if the main threat to the sea comes from fishing, and one stops fishing, there will be a change to a more natural state. Fish can grow older and bigger and they become more numerous as well. So if the sea were fished down to 50% of the original fish stock, then a ban on fishing should result in a 100% increase in numbers, and gradually also in the number of old and big fish. But how does that work?

Fishermen keep fishing the sea and for every fish taken, miraculously a replacement appears. How? Apparently fish move around, and they reproduce as well. When mature snapper spawn, the females produce millions of eggs each. Although most are eaten or just vanish, the numbers of young snappers (called recruits) can be very high. After 4-5 years they too begin to reproduce and enter the catchable size class. Then they can get caught. What then makes fish stay inside marine reserves?

The answer is that they don't, at least most fish don't. We never told them where the marine reserves are, and where their boundaries are. At this point we must become aware that the sea has three main habitats:

Most fish are found in the largest two of the three habitats, and all our commercial fish species are found here. The species of the rocky shore are too few in numbers, and are therefore not of commercial importance. So the sad news is that marine reserves do not protect the species that need protection most of all. Marine reserves do not protect commercial fish species. What these fish need is a form of protection that moves along with them, like fisheries regulations. So what do marine reserves protect?

Fixed protected areas along the coast protect a large number of species, but alas, these do not need protection because they are not being threatened by fishing. But there are some exceptions. Shellfish such as scallop and abalone (paua) do not move around much, and they are eagerly fished. So these species enjoy the protection from marine reserves. The question remains: are they threatened? Obviously, where a fishery thrives, there is no overwhelming threat, because limited predation is natural. Paua are often protected by wild coasts where diving is impossible for most of the year. So do they need more protection than that?

It follows that marine reserves are very ineffective at protecting the commercially fished species.
Marine reserves have very little direct fisheries benefits.


f006512: crayfish live mainly on the rocky shore, protected inside cracks and small caves. Divers like the challenge of catching these 'bugs' and they can be very good at this, resulting in low numbers of crayfish remaining. This can clearly spoil marine research and the enjoyment of those who enjoy the natural environment.
f026711: paua (abalone) sit like low hanging fruit on the rock, and are so easy to catch. The animals shown here are between 5 and 10 years old, and there are no small ones in sight. Taking the three shown here, may leave this spot devoid of paua for many years.



 

a pristine environment

Often the sea is compared to the land, and because we have 10-30% of the land protected, therefore we should protect a similar area in the sea. This sounds reasonable, but is in fact entirely misleading. The sea is a different place, so strange in fact that we cannot possibly imagine it. But the following differences are easy to grasp:
The good news is that a marine reserve could  promote a relatively pristine area to that of a paradise. Stop the only remaining threat (fishing) and a marine reserve will begin to look the way the sea was before New Zealand was first discovered - a paradise. If this is really the case, we should have a network of paradises.


the spiritual dimension

Marine reserves can't work just because there is a law and because we have drawn some lines on marine charts. They can work only if:
How to behave in order not to scare the fish
Consider these elements of behaviour which may take years to acquire:
  • patience: fish do not live in the hustle of a 21st century city. Their time has essentially stood still but even so they are busy with their own needs. It is up to you to adapt and ease up and be patient, even though you cannot match theirs ever. Take time. Sit still. Move slowly. Read the signs. We know that your dive time is limited and that time is money, but this does not weigh underwater. You want co-operative subjects, don't you?
  • stress signals: recognise typical signals of distress:
    • erect fins, especially the dorsal fins are a clear warning
    • skittishness, sudden deviations from course, overreacting to your movements
    • to and fro movement as if uncertain whether to flee or to stay
    • turning their backs to you, ready to flee.
    • split schools where one half wants something different from the other
  • size and posturing: you are a big animal and in the fish world, anything bigger than oneself is a danger. So you are by their experience, a very dangerous animal. You can reduce this perception by reducing your size, turning your front towards them (your back works better though), hiding partly behind a stone or plant and not showing your full size. Your bubbles are also part of your size as they ascend to the surface. Thus your size increases with depth.
  • don't use your arms: swimmers instinctively use their arms for swimming and divers also for balancing themselves. But fish are extremely nervous about our arms because these are able to attack sideways, whereas no fish can do that. Use your hands to hold onto a stabilising point and move them only slowly forward/backward and rarely sideward.
For more about behaving successfully underwater, read our opportunities for underwater photographers in the underwater photography section.

your most powerful move forward is retreat - Floor Anthoni (2005)


 
f020931: spearfishing is a challenging and strenuous sport, practised by freedivers. It takes skill, strength and tenacity to stalk and spear fish, but done inside a protected area, it can cause much harm by scaring the fish. Responsible spearfishermen hunt for pelagic fish like trevally and kingfish, that are only fleeting visitors to marine reserves.
f016219: a speared blue moki has escaped the kill because the spear tore loose. Amazingly, such damaged fish can often survive huge wounds as shown here. However, the chance of dying from infection remains high. This blue moki will most certainly remember the incident and pass its fear behaviour on to other fish. 
f022615: a diver quietly takes her time to befriend a group of resting goatfish. Eventually she will be allowed to touch one. Because most people do not exercise such caution, the fish inside marine reserves are not as trusting as one may expect. This photo was taken near Leigh, outside a marine reserve.
f050136: a snorkeldiver has taken time (2 days) to establish a trusting relationship with a large male Sandagers wrasse, eventually caressing and hand-holding it. Imagine for a moment how much mutual trust this requires. Again, this was possible only outside a marine reserve, at the Cavalli Islands.



 

protecting marine biodiversity

The latest thinking about the benefits from marine reserves, is that they are necessary to protect marine biodiversity. It is said that only complete no-take protection can save biodiversity because biodiversity is not just about species but also about their interactions that form habitats. This may sound logical, but is in fact utter rubbish. On the Seafriends web site you will find the many fallacies in this argument extensively rebutted, but here are the main arguments. 


 

marine degradation

The main threat to the sea now comes from marine degradation, caused by runoff from the land. It is also called eutrophication (overnourishment), or 'too much of a good thing'. How can that possibly be a problem? In this area Seafriends has made major contributions to science by recognising this new threat early on (1987) and by studying it ever since, resulting in a number of challenging theories (hypotheses) that all fit together to a consistent new view of the sea: the sea does not work the way we thought. Study the large chapter on marine degradation and what it looks like (decay), and the revolutionary discoveries made with a new plankton tool, the Dark Decay Assay (DDA). But here are its main points.

Our seas as those everywhere in the world have been degrading for many years, even though here in New Zealand it has become very obvious only in the past two decades. 'Sick seas' is a very serious condition that affects all species, yet scientists have not made any attempt at studying it here.
 

f048705: a rich wall with many colourful species and a red pigfish. The fans are gorgonians and the colourful patches on the rock face are carpet sponges. The colourful bushes are bryozoans. Degradation at the Poor Knights islands is just commencing.
f035907: a very degraded habitat in what was once a clear harbour, Port Fitzroy, on Great Barrier Island. In the photo are two species of sponge, both introduced species, and one species of seaweed, the flexible weed. This sad picture represents the sick seas syndrome. This is what we have done to the sea.

 
The diagram shown here shows that degradation is usually accompanied by the water becoming dirtier or murkier as divers say, "the underwater visibility becomes less". With it, the quantity and quality of life diminishes. On left in clear water, one finds seaweeds to a depth of 20-30m, below which the quality of the light is insufficient for seaweeds. With less competition for space, the filterfeeding sponges now populate the vacant rock. In New Zealand, divers can meet an astounding variety of sponges, a good sign of health.
But as the environment degrades and the water turns from blue to green and from green to brown, less and less light penetrates, and the lower seaweed boundary moves up. Although planktonic food becomes richer (so we think), the sponges who depend on it, disappear. It makes degradation difficult to understand - more food, less life. What is going on?

 
The diagram shows the main food chain in the sea as if it were a wedding cake. At the bottom is the phytoplankton which creates plant life from sunlight and nutrients. Directly above it the tier of zooplankton that 'grazes' the plant plankton. Above that the fish larvae that feed on the zoo plankton, and above that the bait fish and finally the table fish that fishermen love to catch. Of course all these species swim in random order through the thin soup of plankton. In order to feed each tier above, the tier below must be bigger, by about 6-10 times. Multiply this out five times, and it becomes clear that over a tonne (1000kg) of phytoplankton is needed to grow one kilogram of table fish.
What we discovered is that scientists all the world over, have not taken serious the planktonic decomposers who recirculate the dead bodies from the plankton. So plankton is not just a thin soup, it is also thin sewage where infections can spread like wildfire. Each sea organism thus lives in a precarious balance (the plankton balance) between the good life (thick soup) and a long life (thin sewage), which are in conflict with one another.
The diagram further shows that fishing takes a small bite from the top of the ecosystem, whereas degradation takes a large bite from the bottom, and is therefore much more damaging - to all species, fished and unfished. Marine reserves (=no fishing) aim to restore the bite from the top but can do nothing to the large bite from the bottom. At the same time fishermen who see fish becoming scarce, think this is caused by overfishing, whereas it is caused by a smaller cake. It now becomes clear why fisheries management can no longer be effective either.



 

observations

One would think that observing the increased fish populations inside marine reserves (called monitoring), would settle the score once and for all, for shouldn't we rely only on what was measured? Unfortunately, many 'success' stories do the rounds, that do not stand up to scrutiny. Read for instance myths1, myths2, myths3 of our large section debunking myths and fallacies in the marine reserves debate. One would have assumed that scientists would have been more careful.
The species most protected by marine reserves are those which are heavily fished commercially, but that do not migrate large distances. Examples of those are shellfish beds like scallops, and crayfish. The diagram shows how the crayfish population at the Goat Island marine reserve increased rapidly to a maximum level in only five years, but suddenly collapsed in 1998. We observed that the collapse happened suddenly after heavy rains and mud storms in winter, that we think, were related to the widening of Goat Island Road. There were major earth works that were not stabilised and poorlly supervised. The crayfish just walked out, and they were caught outside the marine reserve. The fishermen said that the reserve was finally working "because fish finally spilled out", as promised by marine reserves advocates. Notice that the disappearance of five out of six crayfish was not noticed by two scientific groups working with crayfish at the time, even after we warned those scientists, first in December 1998, and later in March 1999 after we completed our own census. The collapse was noticed only during the official lobster-census of 2000.
Note also that since 1992, the Goat Island marine reserve has suffered other severe symptoms of degradation, such as the complete kelpbed death of 92/93 and the urchin kill afterwards. But both are never mentioned in scientific publications as also the public is left in the dark.
One of our mistakes  is to assume that our seas have the same problems as tropical seas but there is no comparison. So we must rely entirely on measurements done here inside and outside our own marine reserves. These results are conflicting as well as disappointing. Let's look at the snapper situation around the Poor Knights Islands, dealt with in more detail in myths7.
In December 1998 the Poor Knights were closed to all forms of fishing, whereas previously one was allowed to fish with unweighted lines in the semi-protected parts of the reserve. Immediately the numbers of snappers began to increase (green curves), but this also happened outside the Poor Knights, at Mokohinau Islands (blue curve) and Cape Brett (purple), neither of which were marine reserves. As it happened, 1998 was an excellent recruitment year for snapper everywhere. Surely the Poor Knights had more snapper, but the relative increase was similar to the unprotected areas. Can we say from this graph how much was due to protection? Probably not. Of course, in time, the snappers outside the reserve will be caught, so we'll wait and see.
The situation becomes more confusing with the second diagram where divers counted snapper visually, as they did for all other species. As you can see, there is a huge difference between the two methods. Why would scientists use a different method and fail to publish the visual census, which we obtained using the Official Information Act? We have always been suspicious of the BUV (Baited Underwater Video), as documented in Frequently Asked Questions.

Of all the fish species, snapper (Pagrus auratus) are least understood, possibly because they do not just migrate randomly and because as scavengers, benefit from the deaths of others. Although most migrate, some set up shop on the reef where they claim a large private space in open water. When they migrate seasonally, they appear to have an aim, that of finding warm water for spawning. Note how their numbers fluctuate wildly from summer (january) to winter (july).
The nature of oasis reserves keeps snappers within, for much the same reasons that oases in the desert (spots where water surfaces) encourages plants and animals to stay. In the sea an oasis is a rocky outcrop surrounded by sand or a sandy spot surrounded by rock. In the first the rock-loving species are 'imprisoned', in the latter the sand-loving ones. It is important to recognise that oases are rare and therefore not normal. Yet scientists do not take care in distinguishing such. For instance, Goat Island marine reserve is unique because of its island, and its location at the end of a 25km long beach (Pakiri Beach), providing the first refuge of shelter and the first rocky habitat. It furthermore has currents exiting and entering the Hauraki Gulf. So it is a perfect stop-over for migrating fish like snapper. What is certain, is that Goat Island is in no way representative of the normal situation. Yet wild claims are made by scientists who should know better.
 
Rather than observing and monitoring snapper, it would be better to monitor the other species, as shown on this diagram. Surprisingly, all the fish that are permanent inhabitants of the Poor Knights, have declined spectacularly. Not shown is how they were already in stark decline before 1998. On the vertical scale, the diagram counts the number of fish in an area about the size of a tennis court (125m2). Horizontally the year. Notice how the red pigfish (Bodianus unimaculatus, orange line) declined by 50% and the butterfish, a plant eater (Odax pullus, brown line) by 90%. For all these fish, their fate looks grim, except for the coastal sweep (Scorpis lineolatus, light blue line, scale x 10) which rose from insignificance to prominence. Note that this was not mentioned in the report to DoC, and we had to tease it out of the data!
So what does all this mean? That marine reserves cause fish to disappear? These curves look like a fisheries collapse inside a marine reserve where no fishing occurs. What is going on?
This is what degradation looks like, the new threat. Marine reserves no longer work in the presence of degradation. They cannot protect biodiversity because they lose both quality and quantity of life. Fisheries regulations can no longer work either. So why do we want more failed reserves, and networks of failed reserves? Why do we want to rob our children of their freedoms, for nothing in return? It doesn't make sense. Furthermore, we gratulate ourselves for having done something, while closing our eyes to the real causes of decline.
 

Marine reserves are like feel-good plasters on a dying patient, not fixing the main problem - Floor Anthoni
important questions and honest answers
The chronic decline of temperate reef fish at the Poor Knights, while fully protected, raises some important questions that demand honest answers.
  • Do marine reserves protect biodiversity when they lose both quantity and quality of life as the curves show? [no]
  • Do marine reserves save the sea in the face of rampant degradation? [no]
  • If this fish decline is happening in our very best marine reserve, what would the situation be with our other marine reserves? [far worse]
  • If this fish decline is happening at the edge of the continental shelf where the water is of much better quality, what would the situation be at the mainland coast? [far worse]
  • If these curves were related to fishing, would it be called a fisheries collapse? [yes]
  • If fish stocks collapse without actually being fished, would fisheries regulations help? [no]
how science works
In the example, scientists did a before-and-after controlled experiment: measure the situation before, apply protection, and measure the situation afterwards. If there is a change, it must have been caused by protection, thus marine protection causes more fish (snapper). However, this is bad science and has unfortunately been common to most marine reserves science [1,2,3]. For good science, the scientist must also prove that nothing else could have caused the effect (more snapper, less others). As you can see, looking at the situation in nearby unprotected areas (Cape Brett and Mokohinau Is) came as an afterthought, as for these control areas, the before measurements are missing [5]. 
As it turned out, the chronic decline of temperate fish, was an unwelcome result, as it 'proved' (by the same logic) that marine reserves cause less of most species, except heavily fished ones. So why was it not mentioned in the report [4] and we had to tease it out of the published data? Does this mean that scientists are selective in their reporting and by doing so, dishonest? Apparently, but why? Notice that in this respect the research was funded by a politically motivated organisation, the Department of Conservation, and like researchers doing research for tobacco companies, they do not want to bite the hand that feeds. Are scientists corruptable? What did other scientists have to say? Well, they stayed mum and no criticism has arisen whatsoever of any flawed marine research done here in NZ, as exposed by Seafriends. What then does this mean? The message to the layperson is loud and clear: can we trust science/scientists at all? Scientific criticism is dead and peer-review does not work. Fortunately Seafriends tries to keep them honest. Think about it: would you ever have known the truth had it not been published here? Who then, must you support?

[1] MPA perspective: the science of marine reserves - how much of it is science? By Trevor Willis, Russell Millar, Russ Babcock & Nick Tolimieri (2003) which has been dissected by us in myths6.
[2] Burdens of evidence and the benefits of marine reserves: putting Descartes before des horse? (PDF) Environmental Conservation 30:97-103. Dissected in myths6.
[3] The New Zealand Marine Reserve Experience: the science behind the politics Russ Babcock (2003). In myths7.
[4] Effects of Poor Knights Islands Marine Reserve on demersal fish populations DOC SCIENCE INTERNAL SERIES 142 (PDF) Christopher M. Denny, Trevor J. Willis, and Russell C. Babcock. No mention is made of the chronic decline of reef fish.
[5] Denny CM, Willis TJ & Babcock RC (2004) Rapid recolonisation of snapper Pagrus auratus: Sparidae within an offshore island marine reserve after implementation of no-take status. Marine Ecology Progress Series 272: 183190. These scientists all too soon concluded that an increase in snapper populations was caused by protection, thereby making an ass of science.

the doctor's dilemma
One often hears arguments like "every little bit helps" and "at least let's do something" or "doing something is better than doing nothing", which has led to most green organisations promoting actions that are of little consequence or that are even wrong and hurtful. Let's remind ourselves of the doctor's dilemma.

If a medical doctor mis-diagnoses his patient, thereby prescribing the wrong cure, and the patient dies, whose fault is that? What if the patient could have been cured had she been given the right medicine? Evidently, a doctor can become his patient's worst enemy if he makes the wrong diagnosis; if he does not understand what is the cause of the symptoms. Likewise a green organisation can become the worst enemy of its own cause, if it does not understand/diagnose the problem. Unfortunately this has become quite commonplace and wide-spread.

An example is the looming extinction of the northern Hectors dolphin or Maui dolphin. All attention is focused on the threat from fishing and set-nets to such extent that all fishing where this dolphin occurs may need to be stopped. But the real cause of the Hectors dolphin's demise is marine degradation or the sick sea syndrome which causes still births and shortens their life span while also diminishing their food supply. We need to halt and reverse the eutrophication of our coastal seas. Failing that, Hectors dolphin will go extinct. Yet nobody is even suggesting that. In the meantime we feel good that at least we have done something.

In a few years from now, the Maui dolphin will be declared extinct as society flounders. Whose fault is that? The farmers who produced the pollution, the fishermen who killed some dolphins in their nets, the politicians who made the laws that didn't work, the green organisations who pushed for these laws, or the scientists who mis-diagnosed the problem? Will the public ever know? Will scientists ever say "we were wrong"? Will politicians reverse set net bans, bans on fishing and marine mammal sanctuaries once the dolphins are extinct?


 
f004414: the Goat Island marine reserve during a fine day before Christmas. The sea is blue and divers are taking their last open water tests. It takes little imagination that this protected area could become a kind of paradise.
f013205: Goat Island marine reserve during a rainy week in winter. Copious amounts of mud have turned the water brown as the land is poisoning the sea. Dense plankton blooms that thrive on the nutrients, cause death of many organisms, but WHY?.



 

the snapper-urchin-kelp myth

A good example of people (and scientists) having lost the plot, is the myth of the snapper-urchin-kelp trophic cascade (food dominoes falling). It goes like this: in protected areas, after a while big snappers grow big enough to crush the sea urchins (Evechinus chloroticus) that sit like low-hanging fruit on the rocks, and they are assisted in this by the also bigger crayfish. These sea urchins are voracious grazers that scrape the rock face with their five teeth, and thereby remove seaweed 'seedlings' and even mature plants. Therefore when there are fewer urchins, the seaweeds have a chance to come back and recolonise the urchin barren zone. Marine reserves are therefore characterised by bigger fish and more and bigger crayfish, few if any urchins, and lots of kelp. Furthermore, the big fish produce more spawn that then leaves reserves to re-establish life outside. It sounds like a compelling story, but is entirely false. Even so, it has been spread far and wide, and is quoted in every respectable science article about marine reserves. There are environmental groups based on this, like Experiencing Marine Reserves and educational web sites, while many university students come to Leigh (often from overseas) to count sea urchins inside and outside the reserve. How could this go so wrong and stay wrong for so long?

 
The map shows the outer Hauraki Gulf and where transects were done. It revealed the extent of kelpbed death of 92/93(white) but also that there was one earlier in 91/92 (grey), just missing Goat Island and Tawharanui.
We have exposed the non-science (nonsense) of the urchin trophic cascades extensively and conclusively in a long document (/issues/cons/science.htm) which makes for interesting and educational reading, particularly because we did our own observations and measurements in that period (/enviro/habitat/survey93.htm) but here is its essence:
  • the kelp invasion of the urchin barrens was found only in two reserves: Goat Island and neighbouring Tawharanui (marked in red on the map). Trying to find it elsewhere led to failed experiments.
  • scientists kept mum about the extensive kelpbed death of 1993, even though it was studied by them and reported upon. Our own research discovered the full extent of the kelpbed deaths and that kelp invasion of the urchin barrens happened only where previously the kelpbed suffered major damage (see map white and grey areas). Scientists only needed to look at Kawau Island and Great Barrier Island (marked yellow) to discover that these places too, had lost their urchin barrens but these are not protected. 
  • scientists kept mum about extensive urchin deaths, first reported by us and later also studied by them. Urchins die from grazing a poisonous dinoflagellate slime (ostreopsis), a product of degradation.
  • an extensive study to find habitat changes in an extensive range of marine reserves from north to south New Zealand, found no effect from protection (less than detectable), but an overwhelming effect from degradation (water murkiness and dust deposition).
  • today (2007) the urchin barrens from the very north to East Cape on the North Island have been overrun by kelp. An unaffected area has become very rare. All this independent of marine protection.
So the vast evidence that the snapper-urchin-kelp trophic cascade is a fallacy and a myth, are there for all to see and one does not need to be a scientist to check it out. Yet, a scientific myth dies only slowly. Why? To find an answer, study our essay about Science, technology and human nature.
 
f023514: a young snapper absconds with a small sea urchin offered to it but sea urchins are not snappers' preferred food.
f045234: mature urchins losing out against nutricious sea lettuce (Ulva lactuca), invading their patch. There are not enough urchins to keep their patch clean.
f049501: seaweeds are invading urchin barrens everywhere. Here at the Cavalli Islands (not a reserve), it is done by featherweed (Carpophyllum plumosum).
f034409: a sea urchin has folded its spines and is already dead and smelly inside while its spines and tubefeet are still moving. Its mistake was to graze the greenish poisonous dinoflagellate slime (ostreopsis), as shown by a clean pink swath.



 

what do marine reserves do well?

The success of marine reserves, measured by the number of visitors, is often taken as proof that they are working to save the environment. As we now understand, this is not the case. But what marine reserves do well, is to protect an area for people's enjoyment. It resolves the conflict between those who use the sea for taking and those who use it for exploration and the joy of being in a natural environment. The two cannot go well together. Here is what marine protected areas do well:
To give an idea about these points, taking photographs of big snapper is much easier inside marine reserves, yet the best dive spots around Leigh are not found inside the Goat Island marine reserve. When all fishing was stopped in the Poor Knights marine reserve, the big snappers became more numerous and noticeable, and after a few years it was even possible to take good photographs of some 'friendly' ones. It showed how easy it is to catch these big fish, as one can toss half a slice of bread in the water, and within minutes a large snapper takes the offerings, from only a few metres away. Complete marine protection at the Poor Knights co-incided with accelerating degradation by which most fish species became far less common. Taking good photos of these has become a problem. One would have thought that crayfish, already protected for twenty years at the Poor Knights, would have come back, but they have not. I have never seen a young crayfish there and old ones are hard to find. See our extensive Poor Knights chapter.
 
 
f219420: snorkelling in the summer is safe and enjoyable for all.
f022122: because people fed the fish, they became very friendly.
0511156: a large group of some 40 children does a guided snorkel dive with Seafriends. They are all dressed in full protective suits for warmth, safety and enjoyment.
f029212: a snorkeldiver approaches a long-tailed stingray in the Poor Knights marine reserve where shallow sandy patches are rare.



Related chapters: (links to other sections)




References: Books and articles
The main references for understanding the myths and fallacies in the marine reserves debate, are found in Science Exposed.


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