What is happening to our sea?
Is New Zealand facing an ecological melt-down?
by Dr J Floor Anthoni (2009)

Within a mere thirty years, New Zealand's seas have been deteriorating beyond belief, affecting all marine species from sponges to dolphins and from plankton to seaweeds. This chapter leads you on a tour of discovery of how and why this happens, and eventually what can and must be done to stop this vicious cycle. It must be very disappointing that this is happening to 'green and clean' New Zealand, but everywhere else in the world the situation is similar or worse, for the same reasons. Be concerned, very concerned. Follow the links for further detailed studies.


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-- Seafriends home -- decay index -- Rev 20090626,

Degrading seas are nothing new as this has been happening all over the world, but for it to happen here in New Zealand, now, needs an explanation. New Zealand is thought of as a 'green and clean' nation, still very much in tune with nature. But nothing could be further from the truth, as the ill health of our coastal waters testifies - the sea is the sump of civilisation; it reveals the truth.

Never before have so few people done so much harm to the environment,
and over such large areas and in such a short time period as here in New Zealand. - Floor Anthoni

The coastal seas in New Zealand have suddenly fallen ill since about 1960, but to a lesser extent earlier still. We discovered this around 1987, reason why the Seafriends Marine Conservation and Education Centre was established in 1990, opening in 1992. We saw how species diminished in numbers or disappeared from large areas, even extending outward to the edge of the continental shelf, and that apparently no species was exempted. Something mysterious was going on. What could this be and how could we fix it?
We are witnessing a rapidly increasing torrent of erosion, a sure sign that we are losing our fertile lands. In the sea we witness the rapid decline in quantity and quality of life over unexpectedly huge areas. The loss of our fisheries is now proceeding rapidly. We are also witnessing the loss of our precious beaches. It could be said that our nation is in an unstoppable ecological melt-down while people remain unconcerned and unaware.

Now some 20 years later, we (Seafriends) can look back on an extraordinary effort that brought all the science together, augmented by our own discoveries. Sadly, you can read about this only on our web site and even here the pieces of the puzzle appear scattered around. Hence this long page which aims to reveal the emerging picture. Remember that the Seafriends website is educational, taking you step by little step, beginning from the very basics, for you to understand how the planet works, and how we are throwing spanners into its clockwork. Consider therefore this page as an overview, an introduction, inviting you to further your studies and eventually towards reading all of this web site.
During two decades of study, we discovered that our knowledge of the sea is entirely inadequate. In fact, nothing in the sea works as expected from our knowledge of the ecology on land. A radically new body of knowledge is needed, some of which we have pioneered ourselves. It should not be surprising then that we at Seafriends, are at odds with mainstream science, and also that mainstream scientists are our most formidable obstacle towards solutions. Read also:
why science needs skeptics,
science, technology & humans,
introduction to marine habitats,
the biorealms of the world,

Nothing in the sea works as expected from our knowledge of the environment on land. - Floor Anthoni

Threats to the marine environment have not been left unnoticed, as the list shows. On top is usually that of fishing, generally considered to be the main threat. However, we contend that this is no longer so. As humans fished the sea, we saw fish stocks decline - a correlation, which is not necessarily proof. But was the decline caused by fishing or by something else? 
In the left column is an indication how perceived threats (in blue) are relevant to the seas in New Zealand (red), with fishing, competition, erosion and farm runoff as most important, chemical pollution and exotic species as hardly relevant, and all others irrelevant. Note that habitat loss and fragmentation (at the bottom of the list) are the worst threats on land. Read also: conservation and marine conservation.

Early on we recognised that fishing and competition for food are no longer the main threats, because many unfished species disappeared faster than fished ones. We also discovered that fisheries management is a fraud but the chapter about this is still in preparation. Read Inconvenient questions for the Minister of Fisheries to begin with.
So we are left with the two main culprits: soil erosion and nutrient discharge, both hard nuts to crack as a lot of knowledge is needed for understanding soil, and hardly anything is known about how soil loss and nutrient discharge affect the sea. Fortunately we made a major breakthrough with a simple but new method to measure the health of aquatic environments, when we discovered that the sea does not work the way we thought. Mainstream science has overlooked the planktonic decomposing bacteria that have a decisive influence on the aquatic environment and the world. They can make the water 'sick' and eventually become a potent killer of aquatic life, beginning with the smallest fry, the zoo plankton and the fish larvae. This is called eutrophication (overnourishing). Read also:
understanding soil,
the plankton balance,
DDA for dummies,
marine conservation,
land conservation,

Planktonic bacteria rule the world. - Floor Anthoni

In recent times the idea that marine reserves can help, has taken the world by storm, but as with many such flash-in-the-pan ideas, they do not pass the reality test. Marine reserves are protected areas in the sea where fishing is prohibited. As expected, the fished species benefit and return to levels resembling a distant past. But many if not most marine reserves disappoint, because they are losing quality and quantity of life instead of gaining . Also in places where fishing was stopped, fish stocks do not recover. Apparently the negative influence of eutrophication is the main problem. In order to save the sea, we must first save the land. Read also:
marine reserves disappoint,
FAQs about marine reserves,
war for marine reserves,
myths & fallacies,
monitoring Goat Island,
monitoring results from DOC

In order to save the sea, we must first save the land.

Although New Zealand has only 4 million inhabitants, it has a considerably larger livestock, not long ago consisting of 50 million sheep and 8 million cattle. Even though these ratios have changed, their total 'footprint' equals that of 200 million people, and some scientists would say even more. Their effluent is not fully recycled on the farm, ending up in the sea where it fertilises the plankton. Add to that an exorbitant amount of erosion, the sea is being overfertilised by over 6 times of what used to be normal. All this precious waste fertilises the plankton in the sea, which leads to over-dense plankton blooms that can become harmful either by the bloom of poisonous species or by the 'rot' caused by planktonic bacteria. As a result, the sea is no longer as productive, while fish 'babies' are being 'born' haphazardly or not at all. Ultimately this leads to the collapse of fish stocks, while fishermen are blaming one another.

Summing it up, New Zealand has precisely the same problems as elsewhere in the world, and these depend on location:
1. soil erosion: soil washes into the sea where the nutrients stored in clay platelets are released. In addition it provides for the micro nutrients of iron and silicium which phytoplankton needs.
2. soil degradation: the loss of soil fertility due to inadequate recycling on the farm, overgrazing and ploughing.
3. human and stock sewage: human sewage is in general, not recycled at all (it is 'treated'), but ends up in the sea in its entirety where it supplies the perfectly balanced fertiliser. This makes the human as polluter rather big (10 times) compared to animals of comparable size.
4. excess fertiliser: modern farming uses the soil as merely a form of hydroponics where the soil itself provides little nutrition, requiring the use of copious amounts of fertiliser. To make matters worse, there is a race going on for producing more with less, resulting in overfertilisation. Excess fertiliser is washed out by rains and ends up in the sea. Note however, that there exists a radical difference between high country pastures and lowland dairy farming, and cropping. Not all application of fertiliser is harmful to the sea! Indeed some is needed to minimise erosion. Be aware.
5. fishing: the world is still overfishing in a race to produce exports from the sea. However, this can relatively easily be controlled. Furthermore, as we have shown, fishing is increasingly threatened by the bacterial 'rot' in the sea and by mismanagement due to misunderstanding.
Ironically, New Zealand, one of the youngest countries (most recently developed) on Earth, follows what is happening elsewhere. Why?
The graph shows the growth of the world's population and use of energy on a logarithmic scale. The three thin lines top left show growth rates of 5, 10 and 100 times per century. As can be seen, the human population has been growing at its fastest rate ever over the past 50 years, while energy use has been growing fast for a century. Note that fishing depended on energy more so than on population, and it has been flattening off for some time (there's less fish and energy is dearer). The amount of water per person has been keeping pace with population growth, but will soon become a problem. Not shown in the graph is the amount of arable land per person and food per person, also imminent problems.
As rapidly growing populations needed more food, they began developing marginal land (on inland hill slopes), which is unsustainable. First the forest is cleared, then the remainder burnt, and finally the soil hoed. Unnoticeably, this also changed the climate, resulting in less rain arriving in the centres of the continents (short-circuiting the water cycle). Deserts expand and crops fail. Eventually the marginal lands degrade and they are abandoned. In the meantime erosion accelerates. In other words, erosion keeps pace with the growth of the population, and this happens everywhere. The problems 1,2,3 and 4 accelerate with the growth of the world's population and New Zealand is part of that.

Sadly the world has been obsessed with the supposed threat from man-made global warming but anyone who has studied this perceived problem, knows that the amount of CO2 in the atmosphere is fully saturated as far as its ability of trapping warmth is concerned. Global warming from excess CO2 is simply not possible! It is not a threat. Indeed more CO2 and a warmer world will help produce more food while reducing erosion as well. It is thus rather disappointing that the world's real problems are not sufficiently acknowledged:

1. soil degradation and soil erosion: more and more arable land is abandoned as its fertility is exhausted after only a few decades of farming. Irrigated soils are becoming salty because there's not enough rain to flush the salt out.
2. shortage of water: deforestation causes less rain. Underground aquifers are drying up. Lakes are evaporating more quickly. Industry requires large amounts of water. Inland glaciers receive less snow and their rivers become smaller. There are more sudden droughts because there is  less water to buffer (even out) temperature variations.
3. degradation of coastal seas: as nutrients, silt and clay end up in the sea, the planktonic bacteria take over, causing loss of life and eventually fisheries collapses.
4. global cooling: we are living in a warm inter-glacial (between ice ages) and one day a new ice age begins. Apart from this, we are entering a new solar cycle with less solar energy and a cooler climate. Double-cropping (2 crops per year) becomes impossible in many places. Crop failures become more common. Famine reigns. Economies collapse.
Living within a limited environment; era of scarcity
What will happen precisely and how soon, of course remains a guess. In the population/energy diagram above we have seen explosive (exponential) growth, similar to a bomb exploding. Well, that is pretty sudden and yes, explosive. But there exists something even more sudden, that of an unstoppable object hitting an unmovable wall. We are in fact in such a situation, living inside a finite box (the ecosystem). As we grow, there is less and less space left in the box, and eventually we cannot breathe anymore. Very suddenly all life stops. An unstoppable growth has reached an unmovable limit. We may be arrogant enough to think that we live within the box we made ourselves (our culture/technology/agriculture), but we depend on fresh air, clean water, pollution cleanup, wild harvest and room to live. In other words we depend on what happens in the left-over space, which provides for these ecosystem services. In the graph shown here I've tried to illustrate this, inventing the mathematics of scarcity, which are really very simple. The graph shows in grey what humans use, and in green how much of nature is left over. As we use more and more, leaving less and less, we move according to the black line, and we have arrived somewhere in the middle. Soon, suddenly and unexpectedly, the ecosystem services become inadequate (red curve). Also species extinctions begin to accelerate, and then the two work together (not shown). We have no idea which will be the first one, or which the severest, but where will we be in 2030 with over 9 billion people? See how sudden threats can arrive and accelerate? For a list of ecosystem services, see biodiversity1.

The degradation in the sea is clearly a case of ecosystem services (diluting and using nutrients) becoming inadequate, leading to loss of the quantity of life (density) and quality of life (biodiversity), all in accordance with above mathematics of scarcity. It should be easy to understand, but there are serious obstacles in the way of understanding and solving our problems, as shown in the diagram.
When dealing with nature, one deals with a complicated machine which often works contrary to intuition, and where everything affects everything else, often in a seemingly irrational way. To make matters worse, one cannot easily conduct experiments, and worst, the sea is so strange that it does not obey the ecological laws that apply to the land. We are really ignorant in this matter.
As the laws of scarcity begin to bite, we will be experiencing more problems, that arrive faster, are more intensive and also more complicated. Against this onslaught we only have our knowledge as weapon, but it too has increasing limitations and uncertainties. It thus appears that we are ill prepared for what is still to come. Worse still, we are keeping our heads in the sand.

After this introduction, we will now leave the other problems of the planet, and focus on what is happening to the sea.

Examples of degradation
Degradation (=stepping down) in the sea is rather difficult to see because some of it is very natural. For instance, one expects the water close to a river mouth to be less healthy than further out in sea, even in the absence of human populations. It just so happens that people like to live close to natural harbours and rivers. Thus the unnatural and the natural are overlapping in a gradient extending from human influence towards where that influence becomes negligible. Even when observed over time, one may see the environment degrading, but is this caused by human influence? Is it caused by pollution or by climate change or by something unknown?
Observing degradation is further hindered by our inability to see what is missing. In addition, very few of us are regular divers, and those who are, are often interested only in harvesting food. Likewise, underwater photographers are interested in snapping that winning shot and marine scientists are interested in collecting data. Very few, if any, can see what is changing under water and document it as well. See principles of degradation. in order to learn how degradation works and how to 'see' what is no longer there.
Not seeing what is missing
In recent years we have had unusually cold summers and winters here in NZ but compensated for by clearer skies and sunny days. Yet people hardly noticed that their balmy barbecue evenings were few and far between. Because of the cold weather, there have hardly been any flies and mosquitos, yet nobody noticed. The cicadas sang only for 4 weeks rather than the usual 9 weeks, and crickets were similarly short-seasoned. There are hardly any young birds. Yet when asked, people didn't notice. Also the sea water has been unusually cold, but there have been no reports about this. The sea has not experienced summer for three years now. Stragglers from warmer waters are absent. Recruitment is poor for many species. These are all very clear signals, but not seen by the vast majority of people, and they are not recorded or reported.

f032601: abundant life in a sheltered place outside currents that feed, yet there's no vacant space. Calcareous flask sponges amongst a dense cover of other sponges. Rikoriko cave, Poor Knights Islands reserve, 100km from Auckland.
f036814: this wall used to be as dense as the one shown left, but is now covered in scruffy zonaria seaweeds and a sprinkling of red carpet sponges. There is much vacant space (purple patches). Arid Island, 60km from Auckland.
f033805: robust sponges looking very sick where once seaweeds stood. Martins Bay, 30km from Auckland.
f035907: mud, deposition, scruffy seaweeds and introduced velvet sponges. Te Matuku marine reserve, 10km from Auckland.

Study many more examples of what decay looks like under water.
Fish mortalities
One would think that fishermen would notice the mass fish mortalities happening now and then, but hardly any do. Fish stocks consist of many year classes, and commercial species roam around quite a lot. So a mass mortality in one place soon evens out by fish migrating there from elsewhere. It has become very common that the mortality happens to an entire year class of recruits (fish babies). But even this is not directly noticeable because the other year classes are still there. Fishermen catch fish at 'legal' sizes, the small adults which are already many years old. So they do not observe the new recruits. But as divers we have observed a number of mass  mortalities, because we were there when it happened. Strangely, these have occurred nine years apart: 1983, 1992, 2001, and will one occur in 2010? Read more in timeline of degradation events.
The map shows my favourite places to harvest scallops (Pecten novaezealandia) but the shellfish are no longer there. What once were scallop beds do not even look like ones. Clearly something went very wrong. The graph shows fisheries data for this area, in essence supporting what we saw. These places are about 60km from Auckland, the main population centre of 1 million people. This is a good example of definite degradation over a twenty year period. But how would other shellfish fisheries fare?

Most shellfish are found precisely where people want to live, inside estuaries or in sheltered straits and coasts. It stands to reason therefore, that they are the first affected by degradation, and indeed, fisheries statistics show that all New Zealand shellfish fisheries have collapsed, with some in their final decline. Most collapses happened within a single decade. These statistics are quite worrisome because the collapses happened to well-managed fisheries. Apparently we appear powerless to the thing that causes it. More importantly, fisheries management is impotent to turn it around. Anything we do in the sea, won't work. We have to go back to the land and save our soils.
Reader, this is what marine degradation looks like. It is something seemingly beyond our control. Note also how it has been accelerating since 1990. We may blame overfishing, which is always true to some extent, but we cannot fix it by doing or not doing something in the sea. Read more in shellfish collapses in NZ, a tragedy.

Only by saving the land can we save the sea.

Marine reserves?
We mentioned marine reserves before and how little they can do for the environment, but because fishing is prohibited, they conclusively show what happens to the environment in the absence of fishing, and the news is bad and conclusive.
The graphs shows how clams declined inside a voluntary reserve at a sheltered coasts inside Auckland. After having noticed the decline of edible shellfish on Cheltenham Beach, it was declared a voluntary protected area where the taking of shellfish was closed for over ten years. Because many people live immediately around this area, it was very actively policed. It was hoped that the shellfish would return, because their decline was blamed on excessive takings. However, rather than recovering, the shellfish declined further. Protecting them obviously did not work.

The Poor Knights islands, located at the edge of the continental shelf, over 100km from Auckland, have already for over 30 years been protected, first voluntarily and later partially. But in 1998 it was closed entirely to all forms of fishing. Enthusiastically, scientists finally began taking stock, in the hope that the beneficial effects of marine reserves could be demonstrated once and for all. Indeed they measured an increase in snapper (Pagrus auratus) but with the dubious Baited Underwater Video technique which tends to exaggerate. In this diagram the visual counts for snapper are shown, with a positive trend and large seasonal variations. In other words, most snapper come and go and are not protected, but the oasis nature of these islands attracts them from afar. Their numbers and sizes increased indeed once fishing stopped.
Read more about our finest marine reserve, the Poor Knights (extensive).
More telling are the declining stocks of nearly all other species, something that began a decade earlier. What we are seeing here is a spectacular fish collapse inside a well protected marine reserve. What's more, the species shown here have never been targeted for fishing. Only one species, the sweep (Scorpis lineolatus) became more numerous, but this species does not belong here as it prefers the degraded waters closer to Auckland. In other words, the waters around these remote islands have degraded in recent years. monitoring results
Poor Knights,
Goat Island,
many other marine reserves,
why marine reserves fail,

To make matters more confusing, scientists at the University of Auckland claimed to have found the effects of trophic cascades (domino effects by one species eating another) in the Goat Island marine reserve. They claimed that marine reserves eventually have large predatory fish capable of eating spiny sea urchins. The barren zones found along the east coast are thought to have been caused by excessive numbers of sea urchins, because there are not enough large snappers to keep them in check. This plausible story is wrong on two counts: barren zones are not caused by grazers but by storms, and scientists' experiments proved the opposite of what they claimed. In the box on right is the result of one experiment that looked at many marine reserves, and found that marine protection (green) has no measurable effect on its habitats, whereas pollution (red) has a considerable influence.
Read further our extensive rebuttal of the snapper-urchin-kelp myth and a short version, and storm barrens.
Effects of environment variables
25  turbidity/ visibility
18  sediment cover
10  depth
  7  slope, aspect
  6  wave exposure
  4  sea urchins in the open
0.5 marine reserve or not
Source: Shears & Babcock 2004, DSIS192

Sick seas?
Already in 1987 it became clear that there was something happening in the sea, so large and so widely spread, as if the water were sick. Less than twenty years later (2003, 2005) we found and proved that this is indeed the case. It may sound unbelievable, but all marine scientists over a period of a century, have overlooked the most important ecological factor in the sea: the panktonic (suspended) bacteria. It is no exaggeration to say that they rule the sea and because of its size, also the world. The sea does not work the way we thought. In order to understand this, we'll recall  some basic marine ecology which is not difficult to grasp.

The biggest food chain in the sea is that of the open water to a depth of 100m, mainly over continental shelves where nutrients are rich. It begins with the smallest of plants that float in the water, the phytoplankton. Being only one cell in size, they can grow very fast. A typical plankton bloom can be over within one or two weeks. The phytoplankton is 'grazed' upon by invisibly small animals called the zooplankton. These in turn are eaten by fish larvae. The fish larvae are eaten by bait fish which are eaten by the larger predators, our table fish. In the process a lot of energy is wasted, so that the biomass of each higher level (trophic level = food level) is about ten times smaller than the level below it. To achieve one kg growth of table fish, one needs 10x10x10x10=10,000 kg of phytoplankton. Note that these figures are not exact but serve only to give an idea of the whole. The foodchain is also more complicated and rapid cycling behaves as if there is more biomass.
The food chain itself is not a complete ecosystem since the loop is not closed, as shown here where two new components are added: the benthic (=bottom) decomposers that decompose wastes and dead matter raining from above, converting it back into nutrients that feed the plant plankton. The decomposers consist of tiers of feeders like crabs able to cut dead animals to pieces, detritus feeders like worms, and bacteria. Of these the bacteria do the most difficult work, that of turning biomolecules into nutrients (=liquid salts). Today, mainstream science still thinks that this is all there is to it, but we discovered that the most important part had been overlooked.
It takes a long time for dead plankton to sink to the sea bottom, and then it takes between 1 and 1000 years for the nutrients to return to the surface (in deep seas). But nature is not stupid. Every litre of seawater contains millions of bacterial cells and many millions more virus particles, all working as planktonic decomposers. Thus when a plant plankter dies, it is almost immediately decomposed such that one third of the nutrients return to the surface within one week (depending on temperature). The same goes for zoo plankton. However, bigger waste pellets and dead fish do sink to the bottom to be decomposed there. Our measurements showed that the planktonic decomposers often form a larger biomass than the phytoplankton, particularly in sick seas.

The importance of the discovery of the planktonic decomposers cannot be overstated as they have the largest influence on marine ecosystems. Designed to break biomatter apart, they are of the infectious type, ready to kill also living creatures. Living in the sea is not like living on land, where one can breathe pure and uncontaminated air. In the sea one breathes contaminated water. It is like living inside a mix of thin soup and thin sewage. Where the soup is thick, life is fast and short. Where the soup is thin, life is frugal but long-lived. Thus highest biodiversity is found where food is scarce and bacterial rot least. Likewise, eutrophication is caused by dense food and dense decomposers, resulting in loss of life and biodiversity - exactly what is observed world-wide. But there is more to it.

The planktonic decomposers also have a selective influence on which species make up the phytoplankton. Under the influence of bacterial rot, only the most hardy of plant plankters can survive, the ones with little exposure, fast growth rates or those with armaments. These properties also make them difficult to digest by the small zooplankters. Thus the amount of food entering the food chain slows down leading to the observed fish starving in green seas full of food syndrome. The bacteria strive to optimise the ecosystem to suit themselves, eventually stealing all solar energy in a tight loop to the exclusion of others: phytoplankton => decomposers => nutrients => phytoplankton.
Once their numbers are high enough, the planktonic decomposers will attack all organisms with thin skins, including fish larvae. In degrading seas, they are thus the main reason for erratic fish recruitment and eventually a total collapse of fish stocks and commercial fisheries. In this diagram the food chain is depicted as a wedding cake, with its base tier consisting of phytoplankton and every tier above it, much smaller. Of this whole ecosystem, fishing takes a bite from the top, which is always a small part of the whole, even when done to excess. Degradation on the other hand, takes a big bite from the bottom tiers, which causes all tiers above to become smaller too (bottom-up effect). To fishermen it even looks like overfishing, reason why it is not being acknowledged. Marine reserves which essentially try to 'glue' the fisherman's bite back onto the cake, cannot do the same with the bite from bacteria, reason why they are disappointing. They fail to protect biodiversity where degradation is found.

From what we've discussed so far, it is clear that degradation (through eutrophication) is a formidable and uncontrollable threat that eclipses the threat from fishing almost everywhere in the world. Where fisheries collapsed and did not recover after a period of respite (temporary period of relief), degradation must be suspected. It is now equally clear that marine reserves and fisheries management can no longer deliver where degradation reigns (most everywhere).
While perhaps of less importance in this review chapter, we discovered another stunning omission in marine science, perhaps the biggest blunder of all science over all ages. What scientists safely assumed, is that bacteria can strip hydrogen, carbon and oxygen atoms from biomatter, leaving only liquid salts (nutrients) for plants. However, there are energy conversion losses and losses from living, growing and multiplying. In other words, this is not fully possible! Decomposition in the darkness of the soil (or in the dark deep) must stop prematurely, leaving a cocktail of short biomolecules un-decomposed. We discovered this by measurements, and named it slush (after incompletely molten snow). The amount of slush in the oceans is very very large, larger than all other life on Earth combined! Animals can't eat it, plants can't use it and neither can bacteria.
All life on Earth would have ended as soon as it began, if there were no use for slush. But nature is not stupid. Slush is left over because bacteria run out of energy, so once the missing energy is supplied externally, decomposition can complete fully. We simulated this in our test vials.
In nature only plants can supply solar energy in the form of sugars. So they team up with bacteria on their skins (roots for land plants), supplying sugars and slime to grow in. Scientists have observed this, but could not explain why. As plants supply small amounts of sugar enabling the decomposers to complete their work, the symbiotic decomposers supply them the missing nutrients and carbondioxide. In the sea it is of cardinal importance that they also lower the alkalinity, which leads to higher productivity. In fact, some large phytoplankters live with symbiotic decomposers on their skins, giving them an untold advantage over others.
This knowledge now also solves the paradox of wy corals can be so productive in seas devoid of food and nutrients. Coral polyps live in symbiosis with  plant cells in their skins or zooxanthella (dinoflagellate symbiodinium spp.). But these plant cells need nutrients, which they obtain by supplying sugars to a carpet of symbiotic decomposing bacteria living in the slime on the skin of the coral polyp. The symbiotic bacteria obtain these nutrients by decomposing slush which is in plentiful supply, even in seas devoid of nutrients. Scientists have observed coral slime with bacteria and a copious supply of sugars, but they do not know why.

Read more about these new discoveries with our Dark Decay Assay method and our attempts to maintain a true ecosystem in our marine aquariums. Note that our important discoveries in 2003 and 2005 have not been acknowledged nor proved wrong by mainstream science.

Sources of nutrients and their effects
It is true that humans are the cause of all their problems - no people no problems. The diagram shows on left some human activities; in the middle the agents or intermediary substances and on the right their effects on the environment. It is mostly a two-step process. For instance, urban development and roading is accompanied by the displacement of earth, causing mud to enter the sea. The mud can suffocate organisms breathing and feeding from it. It also obscures the light, leading to death of plants and plankton, thus reducing the amount of available food. Mud also releases nutrients which feed plankton blooms. When poisonous, these can lead directly to fish kills, but otherwise the decomposing bacteria will do this. And so on.
There are many arrows and perhaps even a few missing ones. Some are fat (main problems), whereas some are thin (minor problems). The point to remember is that we need to reduce all in size (to one quarter) if we are serious about saving our seas. But in the meantime, human activities and wastes are planned to quadruple in the foreseeable future. What chance do we have? But there may be a silver lining around the dark cloud.
Deepen your understanding in the large sections of oceanography, soil and conservation.
Most biological processes are not linear but optimal as shown here with how nutrients affect the growth of plants. If there are no nutrients, plants cannot exist, corresponding to the leftmost origin (0,0) of the curve. From there on begins an almost linear relationship A where doubling of nutrients results in doubling of plant growth and size. But there is a point B where more nutrients no longer have effect. From there on it goes steeply downhill C until death follows D. It can now be understood that degradation proceeds rapidly once it begins (C). 
The situation in our seas is now at C, and here in New Zealand the natural situation (before people came) was below A, a sea with a shortage of nutrients. Around large continents, the situation is different because there is more land to supply the coast with nutrients. In places without a continental shelf which essentially stores and recycles nutrients, the situation is different again.
The point is that by moving back from C to B (25% improvement), a disproportionately large improvement is experienced, and by improving yet another 25%, the sea will be at its optimum productivity. Note that this does not necessarily also mean optimum biodiversity, because high biodiversity in the sea is where food is scarce.
Reader please note that this curve and its effects in the sea have not been proved by experiment, but many other ecological experiments produced similar curves. Read more about the principles of degradation.

What can we do?
There exists no 'silver bullet', a single solution, because humanity's problems derive from thousands of actions by millions of people. Fortunately, we all live on the land where the problems originate. Alas, whereas nature is not stupid, people are. Worse still, they don't know this and we cannot experiment by trial and error like nature did (there's no time, not enough money). So we must use all our rationality to find the right solutions and do the right things from the start. And guess what? The greenies who are so concerned about our planet, do mostly the wrong things, and greenness is now also done for profit; it is even used for political power! Read the linked chapters carefully and despair! Not only have we stuffed up the environment, but we degraded our minds and our media as well. We must do the right things for the right reasons at the right time. Yet can you mention one example where we did?
Read more:
Science, technology & humans,
Threats to the world,
Belief systems of the world,
War for marine reserves intro,
Science needs skeptics,
Acidic oceans a threat?,
The political mind-set,

We must do the right things for the right reasons at the right time.
We owe this to our children.

At the beginning of this chapter we identified the five foremost ecological problems with the sea, and for each we'll now present the foremost solution:
1. soil erosion
Contrary to expectation, the main cause of erosion comes from raindrop impact which increases rapidly with raindrop size. A 5mm raindrop causes 500 times more impact energy than a 1mm raindrop. It explains why so much erosion happens during heavy downpours. This kind of damage can be avoided with relative ease:
  • grow denser crops with more foliage shielding the soil below.
  • leave pastures in long grass during the rainy season. Do not graze or mow tightly.
  • use ground cover or mulch after baring the soil, as in urban development.
  • leave stubble (crop remains) on the land during the winter rains.
  • avoid ploughing and earthworks when it is likely to rain soon.
Read more about this in our excellent chapter on erosion which also has other remedies.

2. soil degradation:
The main problem with soil degradation stems from overgrazing, a term which is poorly understood. Its main cause is inadequate recycling on the farm. For a sheep to grow, it has to eat 10-20 times its weight in grass, which means that the grass is recycled many times. This cycle transfers the nutrients from the sheep to the soil and then back to the grass. If this loop is only 90% efficient, it means that during each cycle, 10% of the fertility of the land is lost. Multiply that with the number of cycles to raise a sheep (or other grazer), and a farm loses 1-2 sheep to the sea for every one raised. It is an invisible but sad loss, also harmful to the sea.
The remedy must be found in a change of mindset (way of thinking). Farmers all too easily think that they are farming sheep (or cattle or so) but an instance of thought makes them realise that farming grass is a better idea. The sheep just follow from there. However, when one considers that the vast biomass on a farm is found underground in the soil, a farmer must revise his thinking yet again: he is primarily farming soil. If there is less of it next year, his farming is unsustainable! From the soil, the grass and the sheep just follow.
But what should one do to farm soil? For this one needs to study what soil needs (see soil/fertility):

3. human sewage
Humans invented the water closet (WC) to get rid of human wastes. It is an efficient method because water can be pumped with ease. The water closet has been most beneficial to human health and to the growth of cities. However, it is not the most ecologically-friendly way because the wastes are not recycled back to the land. Instead they end up in a sewage treatment plant where bacteria decompose the waste further. Such factories have become very sophisticated, now also removing macro nutrients like phosphorus and nitrogen. The water leaving the factory is claimed to be drinkable, because most human pathogens (disease bacteria and viruses) died. However, the water still remains a potent fertiliser once admitted to the sea, which always degrades close to populated cities.
It is clear that spending more money on sewage treatment is not going to make the problem go away. Instead, a more basic solution is required. It is entirely feasible to pump the sewage into tanker ships, much like oil is pumped. The tankers can then be set on a course to spread the wastes over large areas outside the continental shelves. It is like creating a huge diluted sewage treatment plant, millions of times larger and more powerful than the man-made ones. The diluted sewage is converted to nutrients by the planktonic bacteria (and some will sink to the bottom), fertilising a piece of the ocean where nutrients are in short supply. In this manner an entirely new fishery is created outside the continental shelves, while at the same time the old coastal fisheries are saved. Landbased sewage treatment will no longer be necessary.
One may wonder why this simple solution is not done or even thought about?
4. excess fertiliser
Fertilisers are used to excess where soils are no longer productive, having lost their soil biota, such as in most cropping situations. The crops are supposed to absorb these nutrients, but rains may get to them first (nutrients= soluble salts). Fertilisers are also used to excess where strong competitive pressure drives farmers to produce more from the same land in a time when fertilisers are cheap. It is typical of dairy farming (for milk). Fortunately, dairy farms are mostly on flat land where outwashing by rains is not severe. Problems can be expected when dairy spreads to less sustainable (steeper) soils. Excess fertiliser use is difficult to combat because of competitive pressure and greed. It is also difficult to evaluate (measure) and its harmful effects on the soil take some time to manifest (show).

5. fishing - an example from New Zealand but very similar elsewhere.
In New Zealand the fishery is managed by a Quota Management System, which essentially guarantees all fish in the sea and all future catches to a few big players (a small allowance is made for amateurs). It is not to be proud of. Controlling such a system is tricky because of the power of the big stakeholders. However, once rules are made, they are being adhered to. Alas, the scientific basis of our fisheries management is still the same as found elsewhere (Maximum Sustainable Yield at low (20% of original) Biomass, 20%BMSY). It is not surprising then that our shellfish fisheries collapsed and various coastal fish stocks are in trouble.
At the time of this writing (June 2009), there is a serious debate going on between five camps: Obviously there exists plenty of conflict. But the real issue has not been covered, of how to manage a fishery which is in decline because of ocean degradation. Dividing the fish is not going to work. This gives weight to the demand of the recreational sector who want to leave more fish in the water, with many advantages, while reducing the risk from overfishing. It also bucks the 20%BMSY fraud and makes marine reserves unnecessary (unexploited populations do not exist in nature). (see inconvenient questions for the Minister of Fisheries)
The thought that we need to save the land first if we want to save the sea, has not yet arisen in either camp. It remains in the too-hard bucket.

At the time of writing, our section about fisheries was not yet written. Follow the fisheries debate from the Option4 website instead.

Around the time of writing this page, a report commissioned by the NZ Minister of Fisheries, became available:
A review of land-based effects on coastal fisheries and supporting biodiversity in New Zealand, by M A Morrison et al. (2009). See the MFish web site www.mfish.govt.nz and click on publications.
The report reviews what is known locally and internationally about the effects of run-off from the land on fisheries. Its 102 pages are worth reading because it shows how little is known and that the Seafriends web site has covered this subject extensively. It also shows how scientists still haven't grasped the importance of planktonic decomposers, as discovered by us. Furthermore, the report shows how scientists are exaggerating biogenic (life-forming) habitats and their benefit to fisheries. Throughout the report, as shown by many authors, correlation is taken as proof for causation. For instance, finding young fish in eelgrass is taken as proof for "eelgrass being critically important for young fish", rather than "where eelgras thrives, environmental conditions are also good for young fish", and consequently "where eelgrass disappears, environmental conditions for young fish are also detrimental".
However, you'll like some statements in the summary: "Most fisheries are now managed under the Quota Management System which generally applies Maximum Sustainable Yield (MSY) targets, under which stocks are fished down to a level where productivity is thought to be highest", and "It is also assumed that environmental influences on the stock and the carrying capacity of the system remain constant over time ..." and "These environmental impacts have happened over the same time frame as that of the establishment and subsequent over-fishing of, coastal fisheries, and have driven population trends in the same direction, i.e., in a negative direction for most species (but not all)."  In other words, "The possible effects of environmental and habitat degradation on these fished populations have been largely ignored." [They are also ignored in fisheries models]