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what is marine conservation?
what is a Marine Protected Area (MPA)?
what are Mataitai and Taiapure reserves?
what is a marine reserve?
what is a de-facto marine reserve?
what is it that marine reserves do best?
does trawling destroy marine habitats and biodiversity?
do marine reserves help fisheries?  (updated March 2007)
do marine reserves have more fish?
how are fish counted?
do marine reserves reduce fishing pressure overall?
do we need networks of marine reserves?
are marine reserves needed because fisheries are failing everywhere?
should we have marine reserves where no threats exist?
should we have marine reserves near cities?
should we hurry into creating more marine reserves?
what are good and bad practices for setting up marine reserves?
have existing marine reserves been evaluated?
how many reserves do we have and where?
are protected areas created by Min of Fisheries marine reserves?
do marine reserves protect biodiversity?
do we need to protect every habitat in order to protect biodiversity? (10 Aug 2007)
do marine reserves provide an insurance?
can marine reserves provide resilience against threats from pollution?
how serious is degradation?
how can degradation be bad as bacterium species increase in number?
can marine reserves fail?
what are the Five Myths of conservation and restoration?     (9 Aug 2005)
the early Maori burnt large areas of forest - why is the European burn worse?
why does sewage damage when treatment plants are so safe?
why do I see little degradation on the intertidal rocky shore?
is the Goat Island marine reserve a success story?
can we learn from situations overseas?
why is so much wrong with marine reserve science?
will more research improve the quality of our marine reserves?
how many marine reserves are needed, and where?
on land we have more than 10% of protected areas and national parks, why not in the sea?
do marine reserves create great fishing spots?
why do fish spill out of a marine reserve?
are fish larvae spilling out?
what is the thistledown effect?
do marine reserves produce more spawning mass?
do marine reserves recruit more fish than outside?
do scientists benefit from marine reserves?
would more marine reserves make Goat Island less visited?
marine reserves cause the kelpbed to expand and sea urchins to disappear. Is this true?
what is the real urchin story?
is it better to have more kelp?
is there a need for a Marine Reserves Act?
is the Department of Conservation the best guardian of marine reserves?
can concessions control problems inside a marine reserve?
does the public have access to marine reserves?
how should marine reserves be managed?
what are our main problems in managing the seas?
what is the situation overseas?
I can't escape the conclusion that I have been deceived. Is this true?
what is Seafriends' position on marine reserves?
how can I help?
do you have some exercises?

Fortunately, the situation in the sea is entirely different. Here the habitats have not been changed by human farming, habitation, industry, roads and more. Also, in the sea all areas are interconnected. There are no islands under water as they are above the water. So conservation of our seas makes a better chance. But like the situation on land, marine conservation works only when all threats are taken away.

Should you wish to read more about the principles of conservation, visit Seafriends/conservation/principles. Should you wish to know how much the sea differs from the land, read Seafriends/conservation/biodiversity/marine.

Taiapure reserves may be declared in estuarine and coastal waters that have customarily been of special significance to any iwi or hapu (tribe) as a source of food for spiritual or cultural reasons. Although a Taiapure is managed by Maori, other fishermen have access, and commercial fishing may occasionally be allowed.

To find out more about how many of these reserves have been created and where, visit the MoF web site or Seafriends/reserves .

However, most marine reserves created today will not even come close to this ideal, because of a number of reasons. See how marine reserves can fail, below. But those located far away from civilisation, such as the Kermadecs, Auckland Islands and others, indeed come close to this ideal. Their remoteness has afforded them de-facto protection through the ages.

Very remote islands, when also unproductive, can enjoy de-facto marine reserve status, since they are essentially economic deserts. The Kermadec Islands are of such nature.

• protecting a unique spot: some places in the sea, such as around offshore islands, are hot spots of biodiversity surrounded by a much poorer sea and sea bottom. Islands attract fish towards their shallows. They work like oases, attracting life from far around, including sea birds and sea mammals.
• protecting scientific experiments: scientists need to be assured that over time, the equipment and cages in the sea remain undisturbed, also the species and individuals that they are studying.
• separating takers from lookers: people who take from the sea, particularly spear fishermen, can cause tremendous harm to a protected area where fish have learnt to trust people. People who come to observe the natural environment must be assured that it will still be the same, and perhaps even better when they return next time.
• attracting people where access is easy: given the choice to go to a beach outside a marine reserve, or one within, people will choose the reserve, because there is more to see and the fish are more friendly.
• helping marine education: where else would you like to take children for their first encounter? Besides, the rocky shore in many places outside marine reserves has been stripped barren.
• helping underwater photographers: more fish, tamer fish, larger fish.
• helping to rebuild marine community structure: only large marine reserves with relatively little spillover rebuild their ecosystems to a natural state with large predators and other old species. This happens only where no other threats remain such as from mud, dense plankton blooms or poisonous plankton blooms. Because many fish change sex (female to male) at a late age, a reserve can improve the sex ratio of some fish. However this also increases competition between males.

The shrimp net is of moderate width (5-10m) riding on two sleds connected by a beam above the ground. A tickler chain with rollers entices shrimps to jump up and into the net which trails behind. The net has a very fine mesh to retain shrimps. Thus it also retains small fish. Because the juveniles of many species recruit and grow in the shallows where the shrimps are found (3-10m deep), a shrimp net is very destructive to other fisheries, but not as much to the sea soil which is perturbed by every storm at these depths. In the tropics, shrimp nets catch turtles which may drown. A Turtle Exclusion Devise (TED) has been invented to throw large species out before reaching the cod end (tapered bag).

The standard trawl net has varying width from 10-20m for a single trawler to 50-100m for pair trawlers. The net has a coarse mesh designed to let undersized fish through. It is kept open by otterboards (weighted hydrofoil wings) which slide over the bottom, able to dig a furrow of up to a finger depth. The rest of the net has little influence since the weight of fish under water is practically nil. Its influence on the sea bottom is almost negligible but fishers are known to trawl their sleds through beds of clams in order to damage these to attract fish.

The deep water trawl net is a very large net (100-200m wide), trawled with precision for depth. Most trawls do not touch the bottom, but it is known that they have been used in a risky manner to skim sea mounts with delicate life.

When protagonists complain about alteration and destruction of sea bottom habitats, they imagine sea bottoms full of fragile organisms being smashed by hard metal at high speed. However, most of the trawled sea bottom consists of mud, muddy sand and sand or coarse shell. Here and there an opportunistic species can be found (soft coral, sponge, hydroid, seasquirt) on a stone or other hard bit. But there exist places in the sea with low profile rock covered in fragile and old sea life, particularly in places with clear water where sea currents scour mud and sand away while providing much needed food. Such places deserve protection, but they are found only by fishing them first.

Although fshing may alter a habitat, it takes much more damage to threaten biodiversity. Biodiversity entails viable populations of all species. As long as the conditions for recovery remain, populations can and will recover after fishing has become uneconomic. Where sessile organisms have been broken, they often continue living while contributing to procreation. There has been no record of extinction from overfishing in the sea, contrary to the situation on land.
However, it is more prudent to prevent overfishing and collateral damage. We must change our ways rather than believing that marine reserves will fix all ailments.

When divers count fish, their very presence affects their results, by on the one hand shying some fish away, and on the other hand double-counting those who follow them. The baited underwater video (BUV) technique is worse still, in that it attempts to lure fish from far away towards the camera. One pilchard tied to the outside of the bait box, even feeds (rewards) the fishes. In doing so, it under-counts those who are not hungry or not interested in bait, while over-counting those who are hungry and who have an acute sense of smell. Also, the presence of fish attracts other fish, particularly once they rip into the external pilchard. After a standard time of 30 minutes, the maximum number of fish shown is taken as the fish count!

The most worrisome aspect of this techinique is that it is at odds with a scientific principle of measuring apparatus, that of minimising the effects of the apparatus on the quantity measured. By contrast, the baited camera technique maximises its effects. It even creates its own data, because fish attract fish. In other words, it exaggerates. By scientific standards, it is thus a bad measuring instrument. Scientists have never proved its linearity either, meaning a one-to-one correspondence between measured and actual fish numbers. Results from this technique must therefore be interpreted with the utmost care. They are in fact suspect, and the method must be discarded, as should all results obtained with it so far. Yet scientists have not taken this precaution. Why?

Scientists claim that in the Goat Island reserve, fish is over 20x more numerous than outside. They also show that the reserve is so small, that about half the fish have leaked out. These figures are much higher than reported by other scientists. The worrisome consequence of these figures is that they imply that the fish stock outside has been fished down to less than 2% of their original stock. This is not in agreement with fisheries statistics. So, obviously something must be wrong in their interpretation. It would also imply that marine reserves are unsuitable for baseline comparisons, which could have benefited fisheries. When applying these figures to our very large de-facto marine reserves, they imply that astoundingly large stocks of fish of all kind must be found hiding there, which has not been observed.

In some other marine reserves in NZ, similarly high densities have been found (up to 10 times). There is something fishy with these figures because they do not cross-correlate. They are also far out compared with results from marine reserves elsewhere in the world. To use them uncritically for political purposes is bad science. Furthermore, most of our marine reserves do not follow this pattern as they show hardly any increase at all. See myths11 for marine reserve monitoring results.

While scientists were concentrating on only three commercial species (snapper, blue cod, crayfish), they failed to notice that a number of species have disappeared altogether where once they were common. Other populations have reduced their numbers considerably. No effort has been made to monitor indicator species representative of the health of the reserve, so the massive degradation of recent years has been left largely unrecorded. The people managing reserves (DoC) should share some of the blame. Read more in Seafriends/issues/cons/lessons from Leigh  and Marine science exposed .

• Fish spill over from the reserve. So, fishing at the reserve's boundary (fishing the line) is going to make up for the lost area. However, international scientific research has not confirmed this. The best spillover measured, fell short of 35% of the lost fishery. Most reports mention lower percentages. No data is available in NZ.
• More fish eggs are contributed to the plankton, and these will settle out as recruits in the unprotected areas, where they find more food than inside the protected area. International research has shown that fish being about twice in number and double in size, will theoretically contribute threefold to the plankton. However, recruitment depends mostly on other factors than just numbers of eggs (spawn delivers 99.99% food but 0.01% recruitment). Because recruits face fewer predators outside, they have a better chance to grow up there. However, no scientific data is available to confirm or deny this. See also Dr Shipp's report.

An ecological principle says that the bigger fish depend on more food. So they eat more from the reserve, which includes other spawning organisms. Only a small part of this food is converted to spawn. Thus the total spawning mass of all species, emerging from a reserve, is less than outside. How this affects the survival of the spawn of commercial species, is totally unknown.
• People prefer fishing the line: protagonists see more craypots at a reserve's boundary so they conclude that fishing there is better. Little do they realise that this has become the only place where displaced fishermen who previously fished the reserve area, can put their pots. Many recreational fishermen believe that fishing the line gives better results, until they are proved wrong, but many new ones keep trying. The myth dies slowly. With copious amounts of ground bait (berly bombs) one can attract fish from a large distance inside a marine reserve, but only until this stops working too.

Our main commercial fisheries occur over the continental shelves where the main food source originates from plankton. When alive, these organisms either swim or use buoyancy control to remain suspended. But when they die, they either sink down or float up. Thus the two places where food collects are essentially the surface and the bottom of the sea. The sea thus consists of three main habitats:

• the shore: the soft and hard shores form a minuscule border of at most 20m depth and the length of the continent. It is a habitat zone characterised by very high biodiversity but low volume. There is just not enough fish for a commercial fishery.
• the sea bottom: the sandy and muddy sea bottoms extend over the entire continental shelves. It is a monotonous habitat with few markers. As a result, the fish species living here from detritus, worms and crabs, do not set up territories. They essentially migrate slowly in search for food, typically a few hundred metres per day when not actively migrating for spawning.
• the sea surface: not only does dead matter accumulate at the surface, but because the sunlight here is bright, this is where the food is made. Surface schooling fish are typically silver coloured. They do not have markers as to where they are and cannot stay in one place as they are transported by ocean currents and tidal currents. These fish typically migrate tens of kilometres every day.

The effectiveness of a marine reserve depends very much on its design, whereby size is of major importance. Fish inside must essentially stay inside and not wander out at every whim. So they must be able to feed and spawn there. Most marine reserves created so far, are just too small, or they do not join up the areas that fish find important.

Marine reserves do not have fences to keep fish in, thus their boundaries must be natural boundaries. If a reserve is too much connected with an unsafe area, then fish will leak out too much, and a reserve can become unsustainable such that fish stocks do not increase over time. The problem is that a reserve must be connected with other safe areas, for gene exchange to take place. Scientists claim that this is achieved by the free movement of their larvae, but this has not been proved. Furthermore, the mortality of larvae is very high (over 99.99%).

Fishermen claim that the fish they catch, the commercial species, are mainly migratory, which is largely true. These just wander through a reserve, to be caught once they leave it. They are not really part of the reserve community although they take residence there temporarily. Those species that are, however, are not threatened as much. But what fishermen overlook, is that some people fish with set nets, catching the reef fish that do belong to the reef community. What's more, rather than eating their catch, they use the fish to bait their craypots with. Marine reserves do benefit these species. However, due to the limited size of reserves, they do not protect sufficiently large populations to be sustainable.

Protagonists claim that fishermen reap more benefits from the reserve than they lose. This is not true, and has repeatedly been shown by scientific data, in many countries. It can also be proved from ecological principles [1]. The highest benefit ever measured arising from a marine reserve falls short of 35% of the lost fishery. Good reserves that also protect long-lived species, spill no more than 5% of the lost fishery. So a closed area leads to less fish caught overall, and an increase of fishing pressure overall.

[1] For a complete treatment, visit seafriends/marine conservation/larval dispersal.

1. It discounts the presence of larvae originating from the outside, which is a much larger area, albeit less densely stocked. Gene exchange will happen mainly with this unsafe area. Thus the next reserve downstream is not needed for this purpose.
2. Increased fish spawn is not necessarily going to produce more offspring, since most of the fish eggs and larvae serve as food for other species. The biology and ecology of the plankton ecosystems is very much unknown.
3. Many of our commercially fished species move towards spawning grounds, often located far outside any marine reserve. The nature and place of such spawning grounds is still unknown, vary from year to year or shift over time.
4. It can be proved (see [1] above) that the total fish spilling out of a network of marine reserves, will still be a very small part of the lost fishery (30% for small, bad reserves and less than 5% for good, large reserves). See the reasoning in the Question above.

By providing sample areas of pristine stock, fisheries managers can assess the level of the stock in relation to a full-baseline. Their target is to fish at Maximum Sustainable Yield (MSY), which is dangerously close to Unsustainable Yield. However, this implies very large reserves, designed with minimal connectivity, while they should also be allowed to be fished for stock sampling. One of the problems with the world's fisheries is that stock sampling (scientific trawling) is not done enough, and fisheries models rely on catch quantities and catch per unit effort (CPUE) instead, which is highly unreliable. With this method they essentially regard each commercial fish trawl as a scientific fish trawl (with some 'corrections').

By protecting spawning fish stocks, it is hoped that more larvae make it to adult stage. However, fisheries managers have always been able to call for closed seasons and temporarily closed areas. To lock an area up permanently, would not serve the purpose, also because spawning grounds may move around, and they can be large (where warmer water is found).

The main reason scientists are looking at marine reserves for fisheries management, is never told: they have run out of ideas to control fishing in conventional ways. In fact, it can be shown that managed fisheries everywhere have failed because of scientists' failure to understand the marine environment which does not conform to computer models. Ironically, the pro-reserve lobby also uses unproven computer models to prove their claims relating to spillover, larval dispersal, community structure and more. To illustrate this point, marine reserve proponents are now clamouring for zoning as reserves have shown not to work for fisheries [1].

Read the economies of exploitation in Seafriends/resource management/exploitation. and the arguments for X% of the sea in marine reserves: target sizes for marine reseerves.

[1] Newsletter of the World Ocean Observatory W2O: thew2o.net/newsletter.html (early 2007)

Protagonists reason that we should save pristine areas before they get damaged, and this is certainly true for the land, where private ownership invariably leads to deforestation, development and habitation. But the sea is different. Protagonists say that because nobody is using it, there won't be a fight getting it, which is true. But is that a good enough reason to give up a freedom?

We must, however, remember that certain areas in the sea, such as sea mounts, may suffer irreparable damage from trawling. In the deep sea, creatures grow very slowly, and those that have made it to standing height, must be very old indeed, and thus very precious and vulnerable. In such cases preventative conservation is necessary. In general, preventative conservation is necessary in areas of low productivity, where no other threats exist. The Kermadec Islands are a good example.

People often think that fishing is the only and worst threat, but this is not true for most of our coast. Degradation from mud and sewage threatens more species than does fishing, and it is getting worse very rapidly. It now threatens commercially fished species by as much as fishing does, and it threatens spawning and the success of spawning.

The first marine reserve in NZ was created near Leigh in 1975, but it was opened in 1977. That is a quarter century ago, during which time another 15 marine reserves were created. In other words, less than one a year. At this rate it would take over a hundred years to achieve the above presented goals.

If it is true that fish larvae do not travel further than 100km, then marine reserves should be located no further than 100km apart (not proved). New Zealand's coastline is about 15,000km, which demands 150 marine reserves, spread evenly around. In order for a marine reserve to be sustainable, it should be sufficiently large. Experience has shown that 5-10 km2 is insufficient by far, and 50-100km2 is to be preferred, which surmounts to squares of 10km on edge. Such reserves are 20 times the size of that at Goat Island. By this reasoning, a marine reserve should extend for about 10km, spaced by 90km of open access, amounting to 10% of the coastline in 150 reserves, or 150 x 100 = 15,000km2. New Zealand's entire land area is 270,500km2. Our coastal reserves would thus amount to just over 5% of the land area.

To hasten this process, the Minister of Conservation has made NZ$12 million available to 'purchase' 40 marine reserves costing NZ$300,000 each. Madness?

There is no objection against marine reserves for specific purposes, such as for marine research. But to have them to protect biodiversity (UN resolution) is flawed. Protection of biodiversity is having sustainable populations of all species; not necessarily unexploited or pristine populations. Marine reserves are not the best tool for achieving this.

Read more about this in Seafriends/conservation/marine/sustainable networks.

A transparent process where discussions and decisions are kept public, without hidden agendas, without foreclosed decisions and without political and ideological motivations. A process that is not rushed by tight deadlines, one where everyone has a say but where informed debate is encouraged and fostered by education rather than by rose-coloured propaganda followed by aggravation. A proposal that is well documented on what it wishes to achieve, justifying the biological and ecological consequences of various options, illustrated by photographs that are actually taken inside the area so that people can view the situation under water without being deceived. An honest discussion of the benefits but also the disadvantages, which should not need to be brought forward by objectors. Fostering a clear perception that everyone's input will make a difference, and will be worthwhile. A transparent decision procedure, the outcome of which can be appealed against without incurring high legal costs.

Does any of this resemble what is happening today in New Zealand or anywhere else in the world for that matter?

Also read Bob Earll: Working on a Common Agenda. 1999. Marine Forum. UK.

Even the first and most praised of marine reserves at Goat Island, has not been evaluated. While scientists have been busy monitoring the above mentioned species, they have been blind to the loss of many others, and the overall degradation of all habitats within the reserve. The bottom line is that we have learnt little from marine reserves in 25 years. We cannot expect this to improve in the foreseeable future.

It is also fair to say that no method has been developed for doing a marine ecological appraisal. The nearest effort is a species list, which bears little relevance to the health of the environment or whether it degrades or not.
 
 

There exists no good reason to have two types of marine reserve. Thus it makes sense to abolish the Marine Reserves Act altogether so that all means of protection for the sea can be brought under the umbrella of Fisheries.

To make matters worse, the main threats to biodiversity are mud and sewage, and marine reserves do not protect against these. Thus coastal marine reserves do not protect biodiversity at all! This is a major fault in the thinking of many scientists, the United Nations, Governments and their many departments! The proposed Marine Reserves Act 2002 states as its only objective: to protect marine biodiversity! Madness?

There are only three main habitats: the open water, the (soft) sea bottom, and the hard shore. All other habitats are combinations and variations of these three. As species in one community also occur in other communities, we do not need to be concerned to protect all variations of habitats in order to protect biodiversity. Just some of the three main habitats in the various climate zones will do.

See also Introduction to marine habitats, which makes you understand what it means to live in the sea. Also the principles of the intertidal rocky shore.

Since no-take marine reserves affect only fishing, they may provide an insurance for fishing-related accidents. But this only relates to fished species that are resident, which is but a very small part of the total. Who wants to take out such insurance?

Suppose a marine reserve does indeed provide the larvae to restock the outside in case of a fishing related disaster, it would take a very long period before stocks have re-established themselves, often more than ten years. During all that time, the fishery has to be discontinued. Who wants to take out such insurance, especially since better methods are readily available and already being practised? Is there anybody who believes that a protected sea mount hundreds of miles from a damaged one will repopulate it?

Obviously, the insurance argument is seriously flawed.

A very important aspect often overlooked by protagonists, is that marine reserves do not fix the causes of the problems in the sea. They change neither our behaviour nor our methods. They act like plasters here and there covering small parts of a large wound.

The environment does not hang together like a net with nodes and strands of equal importance, but is shaped like a pyramid in which the base is formed by plant life: algae and plant plankton. The amount and quality of this base determines how many and which grazers can be found in the next tier. These in turn determine which and how many primary predators will live in the next tier, and so on through some five stages to the top level of tertiary predators of which many are the commercial fish species. Of course there are influences going down the pyramid but these are very much weaker, and the furthest levels have the least influence. Thus the very peak (apex) affected by fishing has a negligible effect on the base formed by plant life. This also explains that fishing has only a minimal effect on the marine environment.

However, for land-based pollution, the situation is entirely different because it attacks the lowest levels on which all other species depend. Thus the threat from land-based pollution is unlike that from fishing, severe and wide ranging. A marine reserve will in no way be more resistant to such a threat, as has clearly been borne out by New Zealand's marine reserves.

Often a collapse in the fish stock is attributed to overfishing when in fact this is caused by degradation. When, as the diagram shows, a bite is taken out of the bottom of the food pyramid, all tiers above shrink until a new but smaller pyramid is formed. To fishermen this apperas indistinguishable from overfishing.

how serious is degradation? For many reasons, degradation is not easily seen but scientists recently measured its effect by accident as shown on the diagram. We have some 17 coastal marine reserves, and the Poor Knights Islands, located far out in sea on the edge of the continental shelf, is certainly our best, still with the cleanest water of all. Yet we observed a sharp decline in the quantity and quality of fish since the late 1980s, followed by mass mortalities in 1983, 1992 and 2001 (see degradation timeline). After becoming a full marine reserve in 1998, DoC wanted to use it as desperately needed proof that marine reserves are working. Indeed the snapper densities increased as they also increased in non-reserve locations due to good spawning years before (not shown here) but hidden in the data were these graphs of the fish that normally belong at the Poor knights and reproduce there. These are not straglers from warmer or colder waters, and they are not migratory either. What the curves show is the number of fish found in a transect the size of a tennis court, and these are all declining seriously. For instance, butterfish has declined more than ten-fold in only four years! Yet they have never been fished here! Notice how sweep (light blue) is making its debut at the Poor Knights where it normally does not belong, as it inhabits coastal waters such as around Kawau. Seeing what is happening to the best of our marine reserves, it needs little imagination what the fate is of all others. Suppose these curves related to kiwi, kakapo, kaka, kea and so on, wouldn't there have been an outcry of indignation? If this is not serious, then what else is? Read our recent degradation chapter for more.

An elephant has much more genetic information in its genes, which took many hundreds of millions of years to evolve by trial and error. Thus both the amount of evolutionary time and the amount of genetic information in a species are objective measures of quality. Bacteria just do not come near. Besides, it takes only a few days to generate a new bacterium species, and what's more, they can exchange genetic information readily by means of viruses. So the whole idea of species at the bacterium level becomes questionable.

These people say that a spoonful of mud contains X million of bacterium species, whereas a coral reef has only hundreds of fish species and corals. Not only does an enormous gap of quality exist between the two, but these people forget that each living higher organism, due to its shape, houses cavities (guts, gills, scales, etc) which are filled with host-specific parasites and commensals, each in turn with their own cavities of specific organisms and bacteria. Thus a rich environment has myriad selective compartments that add to biodiversity, whereas a putrid mud flat has not. When all this is taken into account, coral reef biodiversity exceeds that of putrid mud flats immensely. Degradation is definitely a path to worse.

In poor countries, marine reserves fail because of corruption, inadequate policing and subsistence fishing, a struggle for life (either my family dies or the fish). Where marine reserves are visited by overseas tourists, the pressure on fishing outside increases to unsustainable levels, in order to feed these visitors. Most reserves fail because they are too small. Particularly when reserves are small, their design becomes critical to their success (location, isolation from unsafe places, natural boundaries, etc). Once a reserve becomes successful, poaching becomes an increasing problem.

Most reserves fail because they address only one threat (taking), ignoring other threats (mud, sewage, poisonous plankton), which are often more damaging, while also impossible to remove. In NZ most reserves have failed for their failed design, location, mud and sewage and mass mortalities from poisonous or infectious plankton blooms.

• the myth of the carbon copy: people think that we can restore or create an ecosystem identical to a copy of a previous or ideal state, as if our goal is an end point. Our aim is particularly the natural or primeval state that existed before human or European settlement. But the sheer number of non-native introduced plant and animal species and changes to climate, atmosphere and soil make such a goal a pipe dream.
• the myth of the field of dreams: we think that if we create the right conditions, the desired ecosystem will self-assemble. But this is not at all how ecosystems work, since an effective restoration of the physical variables may create the template for biotic recovery, but physical structure does not always beget biotic structure, and biotic structure does not necessarily result in similar ecosystem functions across sites. The idea is just too simple.
• the myth of fast-forwarding: we think that we can accelerate ecosystem development by controlling pathways, such as dispersal, colonisation, and community assembly, to reduce the time required to create a functional or desired ecosystem. We thereby assume that we can reliably recreate key processes and links between the biota and physical environment as if we can control the biotic successions that occur after a disturbance. Often restorations are required by law, such as plantings but these usually result in disappointment because the desired trajectory towards the goal may not occur. When a forest is planted, it will not resemble a natural forest for many hundreds of years.
• the myth of the cookbook: we assume that when a particular restoration experience is successful in one area or ecosystem, it also applies to other places. But ecosystem restoration is not like engineering and depends on many variables that are different from place to place and time to time.
• the myth of command and control: often we achieve our goals by active intervention and unending control, or manipulation of physical and biological components of the ecosystem. This Sisyphus Complex [Sisyphus' task in hell was to push a stone uphill, as it came rolling down again] often occurs when the dominant, large-scale drivers of the system have changed and are either not noticed or conveniently ignored and we become fixated on treating symptoms rather than the root of the problem and so become susceptible to failure. For instance, degradation in the sea is the large-scale driver but we remain fixated on treating symptoms such as creating marine reserves.

[1]  Robert H. Hilderbrand, Adam C. Watts, April M Randle (2005): http://www.ecologyandsociety.org/vol10/iss1/art19/

The early Maori burnt large areas of forest - why is the European burn worse? This map shows how New Zealand forests disappeared in the course of history. First look at the light-grey areas. They are the natural barrens of New Zealand, consisting of ice, rock, dry grassland or low shrub. The olive coloured areas are those laid barren by the early Maori in their hunt for moas and while practising shifting agriculture. Most of this consisted of dry scrub land which burnt easily. By the time the Europeans arrived around 1840, the green and brown areas were still in native forest cover. With their steel technology of axes and saws, oxen and horses, carts and trolleys (later motorised) they were able to lay barren the stands of large trees marked in brown.

By contrast, European farmers converted native bush of large trees with deep soils underneath to pasture and arable land. With their mechanised ploughs they were able to make substantial changes to soil structure. Under pasture, the hill country degraded until today it has reached epidemic scale, which is bound to happen after 50-100 years of use. This diagram shows how soils degrade after clearfelling the forest. Only fertilisation can halt the process, but not for hilly land. Once the soil passes the point of no return, it becomes almost impossible to salvage. Much of our coastline, clearfelled by possum damage, fits this category.

The end product is always fertiliser (nutrients). This should be recycled back onto the land, but in the meantime, it has become too diluted, a problem inherited from the use of water for flushing (WC='Water Closet'). Thus the nutrients are pumped out to sea, and for reasons of cost, close to the shore. Here it fertilises the plant plankton, which blooms gratefully. Animal plankton eats the plant plankton, and this forms the beginning of the food chain, which feeds many of our commercial fish species. Thus sewage can be a good thing.

Where it goes wrong, is when nutrient concentrations and plankton concentrations become too high (eutrophication-= overnourishment). Then the balance of the plankton community is upset, and unpredictable things happen, such as poisonous nuisance blooms. Quite unpredictably, plankton can become poisonous, producing some of the most potent toxins known to Man. It poisons the food chain, and many organisms perish. Such could also be our fate.

Dense plankton blooms also obscure the light, and when underwater visibility reduces below 4m, the kelp bed dies. In 1993, this happened over a vast area north of the Hauraki Gulf, including the Goat Island marine reserve. We recently discovered that plankton  is naturally infectious to sea life because it also contains (fish-) wastes and decomposers, and that it can rapidly become a potent killer. Read the Plankton Balance Hypothesis.

In the years 1992-1995, and in 2001-2004, poisonous plankton has caused massive and often invisible mortality of all species, including fish. Right now (2001) many fish have gone missing: kahawai, blue maomao, trevally, koheru and many more. Because of the potency of this problem, and its rapid acceleration (before 1983 it was largely unheard of), we would be foolish not to heed its warnings.

Sewage and mud are also destroying our beaches, invisibly and almost unnoticeably. Read more at Seafriends/oceanography/disappearing beaches.

Why do I see little degradation on the intertidal rocky shore? Mud and diatom strings need calm water before they can settle out. Waves (and strong currents) prevent this. But even when sediment has accrued over a period of calm weather, successive large waves have a cleansing effect. Near the surface it is the sheer force of the water movement which cleanses the rock and organisms. But also in the deep large waves pick up the sand and cleanse the substrate and organisms by scouring them as in sand blasting. In between these zones, the environment is most affected by sedimentation and its devastating effects. Where shelter is found, such as in deep rock pools and undersea caves, sediment accumulates easily. It is here that the first casualties occur.

But since 1990 a new problem presented itself. Rains became heavier and the surrounding land eroded heavily, also because it was starved of fertiliser (In 1986 the Government abolished the subsidy on fertiliser). The waters became murky and mud caused stress and death to many species. In 1998, 85% of all crayfish walked out, and their stock has stayed low. The reserve is now degrading rapidly. Recently, DoC prohibited the feeding of fish, and since then visitor numbers have plummeted as fish also disappeared. End of a success story!

Remember that this used to be the clearest water nearest to Auckland, located along a coast with a very small rain catchment area, and large tracts of sand dunes bordering it. It is not difficult to imagine what is going on elsewhere in New Zealand coastal seas and other marine reserves that are less fortunate.

Study Seafriends/soil/erosion and Seafriends/soil/soil NZ to get a grip on these new problems facing our nation. It may also help to understand what makes New Zealand so special: Seafriends/oceanography/special NZ.

Since humans are predisposed to believe in myths, propaganda must be suspected in all good news. Makers of documentaries often make them to achieve a political outcome, which they can achieve not by lying, but merely by not mentioning unwanted facts and opposing views. For instance, in the entire literature about marine reserve, not a word is mentioned about the detrimental effects from runoff from the land and how this renders marine reserves useless.

Unfortunately, at the moment at least, too much scientific work is politically driven, while equally politically-driven Non-Governmental Organisations (NGOs) have hi-jacked the decision making process. It is sad that our opportunities to learn from others has been compromised.

The pro-reserve lobby has indeed made such a mess of available information that we must insist that we only consider facts proved in our own locality (New Zealand). Even here the quality of research on the benefits of marine reserves is highly coloured and inaccurate. At least we can verify scientists' statements about our own marine environment. Citing successes from overseas is no longer acceptable. Study the poor quality of marine reserves science done here in New Zealand.

The problem does not only relate to marine reserves but mainly to the discipline of marine ecology of which marine reserves are a small part. Bluntly put, marine scientists do not have the foggiest idea of what is going on out there. Why? It is a puzzling question.

The answer must be found in the complexity of the marine environment and our inability to spend long hours there. But the very nature of the scientific experiment, as laid down by Francis Bacon [1] must also be blamed. In the end, scientists themselves cannot but shoulder most of the blame. Let me explain.

Ecology is a complicated study of living things and how they interact, and how in doing so, they change their environment to suit the survival of a community of organisms which all depend on one another. Add to that some freeloaders, and the situation becomes rather complicated. Ecology essentially takes the experiment out of the laboratory, often in such a way that no controlled experiments can be done (before/after, with/without, inside/outside, etc) or can be repeated elsewhere in the world (here/there). This did not deter terrestrial ecologists, because they were at the same time naturalists who tramped the forests and spent most of their lives amongst the vegetation and animals. They did good science just by observing and wondering, culminating in impressive works towards the end of their lives.

The problem with marine scientists is that preciously few are also marine naturalists, diving very frequently on their own accord from own funds for sheer pleasure and for observing and wondering. Add to this that it takes over two decades before one can see order in the apparent confusion that nature presents. Then add many more years before one can read nature's signals the way an aboriginal tracker can. In other words, to become a discerning marine naturalist is a long path of sacrifice and cost, but also one of immense satisfaction. Serious naturalists cannot only gauge a situation accurately, but they are also privy to a glimpse of the future from the trends they observe. In doing so, they may forge ahead of science by one or more decades.

I have followed this path since 1968, and since 1990 full-time. I have learnt to read the messages of nature although there is still so much to learn. I base my knowledge on what scientists say, able to verify every bit. It is here that I have come to disagree with many scientists and the research they do. These people try to fathom the environment by using junior divers to measure arbitrary features, and then behind their desks, deriving far-reaching conclusions that are plainly wrong. In this web site you will find many examples of this.

Let me illustrate their blindness. In 1991/92 massive fish mortality occurred over large areas, left unnoticed. In 2001 this happened again, unnoticed. In oct/nov 1998 over 85% (a four times reduction) of crayfish walked out of the marine reserve due to the massive ingression of mud. Two groups of scientists were working with crayfish at the time and did not notice, even though I personally notified the Establishment twice. I was met with derision, and mud is still not accepted as the cause, neither do they accept 1998 as the year that it happened. A large burrowing heart urchin (Brissus gigas) lives in their thousands right under the Laboratory. Their markings in the sand are large and clearly visible, yet nobody had noticed them. In the late 1990s, the Goat Island Road was upgraded in an environmentally unfriendly way. Hundreds of tonnes of mud slipped into the reserve, displacing and killing organisms. Yet nothing was done about it. The Leigh marine reserve has been degrading badly. Scores of organisms are missing or have declined in numbers. Yet nobody noticed. Twelve of 16 marine reserves are degrading badly. Nobody noticed. And so on.

But the situation is worse still. Some of that Establishment have become vocal protagonists for the marine reserves lobby, believing so much in their cause that they have twisted the facts in favour of a rosy picture. It must be noted that none of these people actually dive, let alone qualify as marine naturalist. Worse still, this disease has spread worldwide, and one can now wade through thousands of publications of thousands of researchers, most of which are based on opinion, seeded with words like marine reserves can and could and would and may and have potential to. Lacking all necessary proof, they have resorted to unverifiable computer models depicting what should or may happen. They are of course not alone in this kind of optimism. UFOlogy and scientology thrive similarly. What they have achieved is that a whole discipline in marine science can no longer be trusted, which is an important message for the public.
The graph shown here is from an excellent introspective article (burdens of proof in PDF, 260KB) that examines the marine reserves scientific literature, concluding that by far most of it is review or opinion (including computer model studies). Of the small amount of fact, most is flawed by insufficiently robust experimental design. Empirical field studies (solid circles), reviews and notes (open circles), theoretical studies and computer modelling (triangles). In the authors' own words:  "it is apparent that much of their raison d’être is advocacy for the establishment of marine reserves in parts of the world that lack them, rather than real attempts to contribute to the science of the field. The difference between science and advocacy in this field is becoming increasingly blurred (Polunin 2002), and we may soon be in the unusual situation of being faced with a greater number of reviews than there is reviewable material." Read also Myths and fallacies 6.

[1] Bacon, Francis (1561-1626), was an English philosopher, essayist, jurist, and statesman.  He was one of the earliest and most influential supporters of empirical (experimental) science and helped develop the scientific method of solving problems. Bacon prescribed the scientific method wich made experimental science great. However, ecology does not fit in because the environment is too large to take inside the laboratory. So other scientific methods are needed, of which the scientific community is unsupportive.
[2] Read Science, technology and human nature www.seafriends.org.nz/issues/probl/science.htm for a discourse on knowledge.

To make matters worse, we have been creating rigid legislation, which does not meet the adaptability that the environment requires. We have failed to inaugurate local management committees which can respond quickly to the day-to-day needs, and changing conditions (like improved knowledge), managing the marine reserve's budget as well. We have failed to harness local knowledge and experience and that of the people who work with the sea from day to day.

Since any group or person can make a reserve proposal, the process has become fragmented, lacking overall vision and strategic approach. More knowledge does not appear to improve this. Every new reserve is created with the same design shortcomings as the very first, as if we haven't learnt at all.

What we must always remember, is that we won't have many bites of the apple. Marine reserves are a gift of the people to the people, hopefully for future generations. As they take the rights of many away, they must be chosen and designed with care. People must understand why. It is a gradual and educational process in which political expediency has no place, neither has cheating, nor fast-tracking.

Dr Bill Ballantine claims that 10% of the sea is a moral minimum. 1600 marine scientists signed a call for 20% of the seas to be protected by the year 2020 [1]. Many others claim higher proportions (30-50%) in order to prevent fishery collapses [2]. Why are their claims so high and so conflicting?
All these claims are based on studies using computer models, bearing out that marine reserves do too little to make much of a difference, hence one needs many of them. Ironically, these scientists condemn fisheries management models as: fish having become particles within homogeneous seas that are fished randomly by unthinking fishers. Yet the models they use suffer from the same problems: fish having become unthinking random particles that disperse randomly. It is an indictment of science that these studies are being accepted so uncritically. Blinded by the only hammer they have, these scientists try hard to use this one and only conservation tool for solving all marine problems, thereby losing sight of the most obvious: let's get fishing right and let's save the land.

[1] Troubled waters; a call to action: a consensus statement backed by 1600 scientists and conservationists. This used to be found on the www.mcbi.org web site, but has been safeguarded to www.seafriends.org.nz/issues/cons/statemt.htm. Also read other scientific consensus statements here. Scientists appear to resort to consensus statements when they want to achieve a political objective for which they do not have sufficient evidence.
[2] Read our chapter on computer modelling studies to determine the target sizes of marine reserve systems (target.htm)

In private ownership, land is threatened by deforestation, development and habitation, which leads to an irreversible ecological change. Saving some before such things happen, makes good sense. However, this is not so in the sea: we do not live there, burn the kelp forests, rip the soil for farming, or build motorways. The sea has largely been spared this kind of ecological rape.

Our terrestrial conservation estate (except for a few islands), is still threatened by invasive and predatory species, and is not safe for our native wildlife. It is poor conservation estate. By comparison, the sea has only few introduced species.

Our sewage and pollution does not run uphill to soil our National Parks, but it runs into the sea, which has become the sump of civilisation. This is the sea's foremost problem.

Thus there exists no compelling reason to have X% of the sea in marine reserves because Y% of the land is protected. This is false logic. Unbelievably, it has become Government policy (Biodiversity strategy).

[1] It is unimaginable how much the sea differs from the land. To get a grip on this, read Seafriends/cons/biodiversity/marine and what it means to live in the sea in Seafriends/enviro/habitat intro.

Fishing cannot be done inside a marine reserve, of course, so it must be done at its boundaries. Unfortunately, because fishermen believe in this, fishing pressure becomes so high so close to the marine reserve, that small marine reserves cannot work because of it. It has been measured that the benefit of spillover, is no more than 35% of the lost fishery, and usually much less. An increase this small, spread over an increased number of takers, results in no appreciable benefit to each. Experienced fishermen say that it is a waste of time to fish close to a marine reserve boundary.

Resident species invariably maintain a territory, which they defend against competitors. On fish prime real estate (usually in shelter or currents, archways and caves), the pressure is high and territories are small. When young fish grow up, they find a place on prime real estate hard to get, so they are pushed to lesser territory or empty territory. Outside the reserve and near its boundaries, exists a lot of empty territory, so the young ones move there. Then they get caught. Fish diffuse (driven by the difference between full and empty) out of a safe area.

Many fish need a lot of space, not for territory, but a place to sleep, an area to feed, a spawning ground and so on. Schooling fish make almost fixed rounds from morning to evening, over appreciable distances, while adjusting to the timing of the tidal currents. If such places are not part of the reserve, which is often the case, they spill over on a daily basis. Then they get caught.

It is not clearly understood what the spatial requirements are for the various fish species. Even prime real estate is not clearly understood, or daily migrations.

Many fish spawn or bask in warm waters, often found elsewhere. Then they are caught.
 
 

Once an egg or a larva or a small fish is in the open water, it drifts where the water takes it, usually outside the reserve. So they all spill out. Conversely, others spill into the marine reserve. Because marine reserves have more and bigger fish, more of their larvae will spill out than in. However most commercial species move out of a reserve in order to spawn, and fish larvae are but a small part of the total spawning mass from nearly every species (seasquirts, sponges, worms, sea stars, crabs, fish, etc). Those species that move little but eat much (barnacles, sea urchins, sea lice, oysters, mussels, etc) produce disproportionately more spawn. It could be said that the main purpose of spawning in the sea, is to make food (99.99%), rather than offspring (0.01%). In all, the situation is quite complicated, and scientists have not been able to prove that marine reserves indeed produce more (commercial) fish larvae, let alone recruits. It must also be noted that the area outside is very much larger, contributing much more to the spawning mass, even though fish densities there are lower. Also many exploited species swim out of a marine reserve to spawn elsewhere. Their recruits do not settle down randomly but have a preference for certain sheltered places that may not be part of any marine reserve.

The intricacies of plankton ecosystems and the role fish larvae play, is totally unknown to such an extent that simple assumptions may prove to be entirely wrong.Why scientists keep hammering the larval dispersal argument shows that they believe more than they should. The reason that so far no scientific proof has been produced may well mean that the arguments are flawed for reasons yet unknown. What is wrong with leaving more fish in the sea? It is such a simple alternative!

Marine organisms have a similar advantage, because their eggs and larvae are carried in the water, while sea currents transport them far away (however, most currents go to-and-fro). Fish larvae can travel 50-100km, and 'stragglers' may arrive from warm waters, 1000km away. The thistledown effect is claimed to give marine reserves a disproportionately large advantage as a source of tiny colonisers, acting like an insurance. It is reasoned that even a small reserve can produce a lot of larvae, an acceptable assumption because fish there are about twice as numerous and a bit larger than outside, producing three times more eggs. Large fish can produce over a million eggs each, by far enough to restock the entire outside, one may think.

However, this is not how nature works in the sea. A vast overkill in larvae (from all species and phyla) is needed to convert the energy of the sun into parcels of energy (little fish) that are large enough for sizeable fish to eat. This happens in stages, which we call the food chain or food web. Thus a predator fish in the end, lives from food produced by its own eggs. It illustrates nature's intricate system of harmony between its many players, and it explains why so many sea creatures are broadcast spawners, wasting almost all their eggs in reproduction. It is a survival strategy that, although wasteful for each, is beneficial for all. It can be said that fish spawn mainly to make food (99.99%) rather than offspring (0.01%). Fisheries scientists, accounting only for some fish species, while believing that a low stock is able to produce enough offspring, apparently are ignorant of the intricacy of such food chains. This is probably one of the main reasons that fisheries worldwide collapsed, even when managed intensively. If we wish to save commercial fisheries, we must manage them with larger stocks. Marine reserves would simply not help. The thistledown effect is a myth, lacking scientific proof and foundation.

However, recruits may settle in preferential areas such as shallow sheltered places (which has been observed), and marine reserves can be designed to include these places. Many species recruit inside estuaries.

There is no reason that much research conducted inside the marine reserve could not have been done outside. Doing it near the Marine Lab is just convenient. However, protagonists claim that all research conducted inside, was possible only inside a marine reserve, which is not true. The fact is, that more and more research is being done outside.

Scientists hope to use marine reserves as baselines for comparing other areas with (fished/nonfished, trawled/nontrawled). However, this has not eventuated because marine reserves so far are too small, and also because one place can differ considerably compared with another. For instance, Goat Island and the Poor Knights are so special, that they cannot be compared with other places. Yet protagonists often do not make this distinction!

The reason is that Goat Island is a special place, with safe swimming, clear water and a lot of interesting underwater habitat. The fish agree. It has good access too, right to its centre. There is no other place further from or nearer to Auckland, with these characteristics. So, no matter how many reserves are created nearer to the City, people will still pass them by, in favour of Goat Island. Furthermore, if Goat Island loses its attraction (by degrading further), there still won't be another place like it anywhere else.

Scientists have seen the kelp settle on urchin habitat (barrens), and these disappeared at two reserves (Goat Island, Tawharanui) but not at four other reserves (Poor Knights, Long Bay, Hahei, Mayor I). They see barrens on the east coast of the North Island but not on the west coast. Snapper are found more so on the east coast. They have found some snapper with urchin spines in their stomachs. The conclusion is: marine reserves protect snapper and crayfish (big predators). They become more numerous and bigger too. They eat more and bigger urchins, who eat kelp. Therefore there are less kelp-eating urchins and the kelp returns, which is better for the environment. There is more diversity and more biomass or productivity.

Unfortunately, this story amounts to the worst scientific work done in this country, for the following compelling reasons:

• It is a failed experiment: the experiment could not prove its hypothesis (all marine reserves lead to loss of barrens), neither could it prove its null-hypothesis (outside, this does not happen). There were just too many exceptions. This is bad science. In the authors' own words: "While reserve-related differences in benthic communities can only be detected for the two oldest reserves at this stage, we may expect continued monitoring to demonstrate similar patterns at other reserves after longer periods of protection". Where is the proof? Other related studies have made matters worse. A study published in 2004 (DSIS192) confirmed this further.
• Why did it happen suddenly? The Goat Island reserve has been stable until 1995/96, when it suddenly happened, at age 18. Next door at Tawharanui it happened simultaneously and at the same rate, at age 14. Scientists reasoned that it did not happen at Hahei and Mayor I because these are much younger (both from 1992, age 4). Is this proof?

Scientist also claim that the kelp invasion happened gradually, but here is an aerial photo taken on 14 April 1999, which shows the urchin barrens (light patches) still largely intact although the kelp is expanding swiftly (dark patches). Read our rebuttal of failed science conservation/science_exposed and our own research habitat/survey93 which follows the kelpbed death and what happened afterwards.
• Why did it also happen outside? Scientists forgot to look at Leigh, Kawau, Little Barrier, Great Barrier, Mokohinau and the Hen, where the barrens also disappeared, but these are not marine reserves. On the map the two marine reserves are shown in red and the nearest areas where the kelp also invaded the urchin barrens, in yellow. What all these places have in common, is that they lost their entire kelp forest in 1993. These places refute both the null-hypothesis and the age argument. Ironically, what scientists attributed to the good influence of a reserve (loss of urchin barrens), was in fact caused by degradation (loss of kelp forest due to dense plankton blooms, folowed by mass urchin mortalities)!
• It was not replicated: all scientific research must be replicated by others, in similar places, before far-reaching conclusions can be drawn and a hypothesis can be accepted as truth. However, since this research was politically driven and funded by DoC, the hypothesis was immediately broadcast here and overseas as the biggest thing since sliced bread (Major ecosystems shifts within marine reserves). Within one year, NZ children were learning it at school! This is sad, and a bleak day for NZ marine science, which will forever be smudged. Somehow, the peer review was not knowledgeable, and nobody in NZ had any idea of rocky shore ecology, or dared to speak up. It shows again, that one should proceed with more caution.

In a recent study [1], marine scientists quantified coastal marine communities in 13 marine reserves spanning the length of New Zealand. They looked at algal communities and their grazers, particularly the green sea urchin Evechinus chloroticus. They also noted environmental variables. To their credit, they also included degradation variables of Secchi disc visibility (the opposite of turbidity) and the percentage sediment cover. Their most important result is the proof that degradation (=turbidity + sediment) is by far the most decisive factor on what grows where. In other words, the seascape cannot be understood without understanding degradation. Marine reserves have no measurable effect on coastal marine communities. Read our chapter on degradation and decay. [1] Shears NT, Babcock R C (2004): Indirect effects of marine reserve protection on New Zealand's rocky coastal marine communities. DOC Science Internal Series DSIS192.

Effects of environment variables 25  turbidity/ visibility 18  sediment cover 10  maximum depth of transect   7  slope, aspect   6  fetch, wave exposure   4  sea urchins in the open   0.5  marine reserve or not

• The kelp bed died: In 1991/92/93 the kelpbed died in the area north of Kawau and south of Whangarei Heads, due to dense plankton blooms which obscured the light.
• The urchins dispersed: there being no boundary of the urchin barrens any more (by kelp), the urchins dispersed to deeper water. It considerably reduced their presence in their traditional zone.
• Kelp recruitment failed: the first kelp recruitment, which happened only in the kelp's traditional zone (a spore bank?), failed because of the many grazers there which had been starved of food for some time, including plant eating fish and even plankton eating fish! They ate most kelp recruits. (1993/94)
• The kelp recruited everywhere: after this fast-response recruitment, new kelp appeared in all zones, including the urchin zone, but this happened more slowly.
• Urchins became ill and many died: perhaps because of reduced grazing, a poisonous alga ( 'brown fluff') settled on many places. Urchins that grazed it, folded their spines and died. Their numbers declined sharply. This scourge has been seen increasing its intensity over the past two decades. Scientists have observed this too (now identified as a poisonous dinoflagellate).
• Urchin recruitment failed: for reasons unknown (same poisonous algae?), juvenile urchins were absent at that time.
• Maximum kelp growth rate: the lack of effective grazing, but particularly the massive invasion of kelp of identical age allowed the kelp population to reach maximal growth, all at the same time, because they recruited massively at the same time. This produced so much biomass that no amount of grazing could keep it in check. Such an event is possible only after a massive die-off. The kelp took over.
• Not everywhere the above sequence of events happened: ONLY in those areas that were denuded in 1993.
• Urchins are not preferred food: both snapper and crayfish do not select urchins as their preferred food. In an aquarium, snapper do not touch urchins, not even small ones. Crayfish prefer sea cucumbers and snails over urchins. Crays are flexible in their choice of food, which includes anemones, and other unlikely species, including algae. It is not likely that these predators will eat their prey down below sustainable levels, which also goes against ecological principles. Underneath the new kelp forest, dense stands of sea urchins can still be found. However, crayfish get attracted to sick or damaged urchins.
• We discovered that the urchin barren zone is created by storms, while grazers like sea urchins, paua and Cooks turban shells just maintain and widen it. The last big storms occurred in 1975 and 1977. The next serious storm from the right direction will recreate the barren zones.
• In 2006 we had enough evidence that showed that urchin barrens have disappeared from the far north to East Cape, and also on outlying islands (Cavallis, Mokohinau, Cuvier, Mercuries, Mayor). Marine degradation appears to be its main cause.