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Monday, September 24, 2007

Commercial Salmon Fishing - what a wasted effort

Commercial salmon fishing has got to be the most wasteful industry you could imagine. The salmon when they are full size come back into their steam or river and you just have to harvest them. Instead we spend huge amounts of money, create masses of green house gases and waste the efforts of thousands of people going after them at sea. And we catch them before they are fully grown. No wonder salmon have become a luxury item rather than a delicious, reasonably priced product. No wonder the stocks have been decimated.

And ....... can someone tell me, why we are farming salmon. Could it be something to do with having destroyed the natural runs. Could it be all the other degradations in their environment we have caused. Salmon farming puts a quantity and quality of pollution into the oceans that wouldn't be allowed from a land based enterprise.

It requires the fishing of 10 kg of "trash fish"* to produce each kg of salmon. The other 9k** in the form of feces and excretion goes right into the sea by the farm. Salmon farming threatens our stocks of wild salmon by polluting migration routs with sea lice, and the fish from salmon farms are an order-of-magnitude richer in PCB's, pesticides and a cocktail of other carcinogenic compounds than wild salmon. Salmon farms use antibiotics which produce antibiotic resistant bacteria in the ocean. Fairly recently it has been found that quite a wide range of supposedly unrelated bacteria species exchange genetic material. Antibiotic resistance spreads from one bacteria to another along pathways we can't even begin to imagine.

*salmon farmers have spent considerable efforts to source some of the necessary protein from land crops rather than from fished anchovy.  So now we use lots of prime agricultural land to grow Soy beans to feed our salmon.

**A salmon farmer will tell you he gets a 2:1 conversion factor.  That is to say, two kg of food produces 1kg of fish.  You would be excussed in thinking that every kg of fish produced introduces 1kg of waste into the ocean.  However they are talking about dry food and wet salmon.  Salmon food is less than 7% water, the salmon, over 80% water.  The true figure is the 10% you learned in school.  ie 10% of the material from one trophic level goes into the next one.  90% back into the environment.

Salmon farming also introduces a range of arthropodicides into the sea to control sea lice, which then threatens food chains based on copepods and amphipods. These compounds are also toxic to commercial crustaceans such as crabs and lobsters which are also arthropods.

For that matter, I don't know why we call it salmon farming. There is no farming involved. Salmon cages are marine feed lots.

Why don't we simply let (or help) the runs to build up to what they once were and harvest them when they return to spawn. You can't even over-fish salmon if you harvest the returning fish correctly since all the fish you harvest would be dead in a month anyway. You have to harvest just below the point in their migration where the quality of the salmon meat begins to decrease and allow enough to get through to completely stock all natural and artificial redds. That's it. End of story. You can even selectively let salmon of superior characteristics through to spawn and improve the breed.

None of this is original or particularly startling. Lauren Donaldson of Washington University worked on salmon and trout from 1932 onward. He produced completely new "artificial" salmon runs at Portage Bay, Seattle and was getting 30 times better returns than found in natural runs. Through selective breeding his salmon were bigger, returned in less years and had more eggs that "natural" salmon. Incidentally, he supplied the majority of the eggs to the great lakes project, to control the alewife which had taken over those inland fresh water oceans. He also produced super-trout which are still the base of trout stocking in many countries of the world.

Although you can't harvest all the fish, depending on the location of your redd, hatchery or artificial spawning channel, you may be able to use the meat of fish which are artificially or naturally spawned. That is the beauty of the system. In addition to the still existing natural redds, you build hatcheries and artificial spawning redds such as exist in many parts of BC. In the hatchery, you choose the best fish to be the parents of the next generation. You only need a small portion of the returning salmon to fully stock hatchery and/or spawning channels and/or natural reds and the rest can be harvested. In a hatchery, if it is quite close to the sea, you can even eat the fish after stripping out the eggs and sperm.

 You have probably seen the pictures of salmon spawning way up the rivers and what bad shape they are in. You certainly wouldn't want to eat any of these. However further down the river nearer the mouth where you might locate your hatchery, (seaward of the first high dam) the fish are still in fine commercial condition. For each species, the exact point where condition begins to decrease, whether still in the estuary, or at the point of entering fresh water or somewhere up the river is where you harvest the excess to what is needed for spawning. Disintegrating fish from further up the river systems can even be used for compost if so desired.

There are a wide variety of salmon to choose from.  They vary from the pink and chum which head out to sea from streams near the mouth of the parent river as soon as they hatch to Sockeye that live for various periods in fresh water lakes before heading to sea.  The variety you choose depends on your local conditions and requirements.

However, the real trick - the key to making the system work - is in allowing the people who operate the salmon producing facilities get the economic benefit from the returning fish. Why should they go to all this effort only to see fishing boats take their salmon.
It is so logical and only needs a "stroke of the pen" to set up. Why do our governments find it so hard to do the necessary.

My favorite hatchery is the Capilano in North Vancouver. Not because it is any better than the other hatcheries in BC but I lived near it as a boy and visited it often.  It is situated just below Cleavland dam.

Link Historically there were natural runs of Steelhead and Coho.  After they built the dam, like Donaldson they started a new run of salmon, in this case Chinook, by hatching eggs of this species in the hatchery. This has resulted in having runs of salmon for about three quarters of the year and an extra very valued fish species. Initially, they truck some of the young salmon above the dam and they also truck some adult salmon above the dam to spawn naturally. I'm not sure if they still do this as it has been found that survival is pretty bad when the young fish pass the dam on their way back to the sea.

The production from the hatchery is allowed to make its way down to the sea when the fish reach the appropriate developmental stage. Their success has been beyond all initial expectations and the runs are now reported to be larger than before the dam was constructed.

Actually, depending on your location, you can often get away without a hatchery. In fact there are some definite advantages of doing so.  In many locations Spawning Channels have been build instead, which are just artificial spawning streams constructed parallel to an existing stream, with suitable gravel on the bottom and often with rip-rap (stone) sides. The spawning success in Spawning Channels in some locations has been found to be 10 times as good on a per-area basis as in natural redds due to the freedom from floods. In a bad year floods can wipe out natural redds. True, you have to clean out the gravel from time to time in the spawning channels since in nature, the very floods which destroy many eggs also clean the gravel. In some spawning channels, the water is first let into a pond where much of the silt settles out before it enters the spawning channel. You also may need to protect the spawning channels from bears, eagles and other predators but after the fish have spawned, the carcases can be distributed to feed these animals.

Why bother giving the spent salmon to the local fauna? The return of nutrients from the sea via the salmon is a vital part of the ecology of coastal forests in salmon country. Via the dung of the salmon-eating animals, these nutrients are spread far and wide.  This is one of the few systems in nature that returns nutrients from the sea to the land.

In a couple of ways, spawning channels may be preferable to hatcheries. There is, of course the issue of cost. It is less expensive to build and operate a spawning channel than to build a hatchery. Of more importance, though, may be the preservation of a robust stock. In a hatchery, there is always the temptation to use various "chemical helpers" such as malachite green or various antibiotics when you see a 'fungus amongus'. (yes I know antibiotics don't work against fungus but there is always the temptation to cover all your bases and avoid secondary infections). These and other measures taken to assure a good result neutralize some of the effects of natural selection which, unlike the popular characterization, does much more to keep a species robust than it does to produce new species.

A spawning channel is much closer to the natural situation than a hatchery and fish that do well in a spawning channel will likely do well in a natural redd. While the vast majority of fish return to their stream and redd of origin there is always some leakage of fish from location to location. Not every fish returns to its original birth place so a successful spawning channel is a source of fish for natural redds. Some species of salmon actually do better in spawning channels than in a hatchery.

And how about expense. Well the Capilano hatchery cost some $3 million Can. to build(many many years ago) and employs about 10 people, some of them involved in tourism and education rather than in fish production. Compare this with operating a fleet of salmon boats and you will see it is cheap by comparison. Spawning channels cost even less to build and run than hatcheries. You are not even restricted to one commercial unit per river or stream. Since by far the majority of the salmon return to their patch of spawning gravel, within certain limits, it is possible to have a number of enterprises in one water-shed. Each business gets back its own fish. Whoever designed this fish was a genius. The limit on how many juveniles you can send down to the sea each year is probably related to the pollution load from feeding the young fish to the stage where they return to the sea. Since they are small and eating much less per fish than when they are older, this is a smaller problem and returning adults don't feed. However, if the legislation is ever set up so that this type of salmon ranching can occur, we will probably even reach this limit. Note, though that the carrying capacity of a stream can be greatly increased with very little cost.Link

Why do we still run fishing fleets. It is the usual story. Vested interest. The fishing companies with their boats already exist and they of course still want to continue to fish and make money. They lobby against anything that will interfere with their prerogatives. The same applies to the salmon farmers. Never mind that the fish stocks would be far better off if we let them all come back to their streams and ensured that enough were allowed/induced to spawn to fill all the natural and artificial redds available. Never mind that pollution from salmon farms is detrimental to wild salmon runs.

To get such a system of salmon ranching working, all rivers with dams or other man caused spawning-reducers such as excessive soil erosion have to be well supplied with hatcheries or spawning channels and the fish harvested when they return. Rivers that still have great spawning runs (there still are one or two) would be fished right by the sea but in a sustainable way, allowing the best fish to pass in sufficient numbers to completely stock all redds.

Since salmon get by far the greatest part of their life-time nutrition from the sea, there is a reasonable chance that with the man-caused demise of all the other sea-fish stocks, that there is a lot of feed left over for salmon. It is possible that we could even end up with greater runs of salmon that were present in pre-historic times as has occurred in the Capilano. Actually it is more likely that we have so degraded the sea that there is less feed available but that remains to be seen. Of most importance, though, the salmon must be allowed to return to the companies that spawned them. It is not fair to expect a business to go to all the expense of growing the juveniles only to have them harvested by boats at sea.

Think of the tourism potential. With great salmon runs on all our rivers, we can increase all aspects of tourism associated with this fish. As in Africa with their animal safaris, we can have fishing safaris both at sea and in our rivers with well heeled Americans coming to rod-fish our waters and bringing in lots of foreign currency. In case you think this goes against the above argument of every facility getting back its own fish, consider the following. A rod fisherman going after a salmon and especially one from overseas, puts so much money into the economy in transportation, guides, accommodation, fees and so forth that his value to the economy hugely exceeds the value of the salmon he catches. Of course a recompense should be directed to the hatcheries and spawning channels by the government, commensurate with their contribution to the economy through tourism. This could take the form of tax rebates.

As in Africa we can have camera safaris with people coming during the spawning season to wonder at our hatcheries, spawning channels and natural redds, and at salmon jumping water falls and digging nests in pristine streams. We can have safaris where they watch the bears and other predators taking their share and they can wonder at the Canadian people who live in harmony with their natural resources instead of fighting them.

If there ever was a fish designed by the creator or by evolution, depending on your point of view, to give us vast quantities of delicious food for ridiculously little effort, the salmon is it. Why do we work so hard to circumvent the obvious system and make life hard for ourselves. Why do we send expensive polluting fishing fleets after these fish when they swim right back to us. Why do we farm these fish at the cost of polluting our coastal water and imperilling our natural runs. Why do we fish 10 kg of "trash" fish to produce each kg of farmed fish when the wild fish don't cost us anything to feed once they have left the hatchery. Why do we farm these fish when it produces an inferior product laced with a cocktail of carcinogenic pollutants.

The latest buzz word is sustainability. If ever there was a species which can be utilized by us in a sustainable way, it is the salmon. Why are we fighting so hard against the obvious.

Sunday, September 23, 2007

The Varoa mite - a possible solution

For those of you unfamiliar with the beast, the varoa mite is a bee parasite and can wipe out the honey and pollination industries of a nation if nothing is done to combat it. Recently it has arrived in the island nation of New Zealand and even more recently has passed from North Island to South Island. Below is suggested a solution to the problem.

Some bees are more or less resistant to varoa mite. It is believed that their grooming habits and/or their hive hygiene regime are responsible. Whatever the reason, the most resistant bee is probably the African Killer bee. Yes the Killer bee. I mention it by its pejorative name to get it out of the way right at the beginning. Despite it name and bad reputation, this is the bee that most of Africa, with the exception of a few enclaves, uses as a domestic bee. Yes he is a pretty tough customer. He has to be to survive in Africa and I certainly wouldn't mess about with an African hive without full protective equipment and a smoker in hand. I would also never take off my protective clothing until I was well away from a hive I had stirred up. African bees will pursue their tormentor for a good long distance before giving up. Oh! and never go near an African bee hive with an operating electric lawn mower. It sends them crazy. On the bright side, the African bee will produce about a third more honey at any given location than the tame bees that most of the world uses.

Fortunately the African bee will hybridize with the Italian bee and here is where a possibility opens up. How about this scenario.

New Zealand is long and narrow. Re-queen a few hives at the north end of North Island with Africans. African queens can be ordered off the shelf from South Africa. This is what they all use over there. These queen will convert the hives to pure African bees. In the fullness of time the drones from these hives will interact with other domestic queens and produce hybrids. From here on nature and the selective process that every bee keeper does as a matter of routine takes over. The varoa mite itself will select out any hives that don't have varoa resistance while the bee keeper, as he has always done, will eliminate really fierce hives.

Incidentally, the bee keeper may find it an advantage to have a bit of African in his bees. It would take a brave vandal to mess with such a hive. As the varoa resistant genes spread down North Island, the bee keepers will be selecting for a reasonable level of gentleness and good productivity. By the time the genes have reached South Island, the Varoa problem should be over and our horticulture industry should be back on track. As an added bonus,honey production could well have improved.

And just a final thought. If we completely converted to the African Bee would that be so bad. Yes, they take more work to handle and you have to wear full protective clothing but our entire agricultural industry is dependent on bees. Fortunately we have lots of bumble bees but they can't fully replace honey bees. Most of Africa uses this bee. We should be able to too.

Wednesday, September 19, 2007

KiwiSaver - $20???

Do you ever get suspicious when someone wants to give you something for nothing. I'm talking about the $20 the government puts into your KiwiSaver account each week as long as you are putting in at least as much.

Lets look at someone on a medium-good annual salary of $60,000 and here I'm talking about a $60,000 cost to the employer. This is what he is prepared to put out for the privilege of having you work for him. You tell him to keep $2,307.69 to put into KiwiSaver, tax free, for you so your taxable income is $57,692.30. Your Kiwi Saver contribution is 4% of your taxable income or 2,307.69. (the same as your employer puts in). This is a weekly contribution of $44.38 from you and the same from your employer (of your money, remember) Since you are in the 33% tax bracket, you had to earn $66.56 to be able to put your $44.38 into Kiwi Saver. Do you see where we are going. The government $20 doesn't quite make up for the amount they charge you in taxes before you deduct this money to put into KiwiSaver. They would have had to give you $22.18 to make up for the taxes they took and we aren't finished yet.

You then earn a dividend on your money. Lets assume you earn 6% which is a historically pretty realistic figure for reasonably low-risk investments. Inflation is running at 3% so for every $100 you invest, you need $103 at the end of the year, just to break even. You end up with $106 but then since you have earned $6 and are in the 33% tax bracket, the government takes $2. You have $104 in the bank which is only a dollar earned in real terms. Index it back to the time of investment and it is worth $0.97. Your real earnings are only 0.97% Get out your pocket calculator and compound this for 45 years (your first investment at age 20 which you take out at age 65) and you have made a grant total gain of just over 50% for a life time of investment. (1.0097 raised to the 45th power, minus 1, times 100) . All subsequent contributions are in for less time and earn even less at retirement.

We haven't even factored in yet the comission that the financial provider takes.

The problem with KiwiSaver is not that you can't find an acceptable investment to put your money in. Do the sums with a 6% investment for 45 years and see what you come up with. Over 45 years a $100 investment becomes $ 1,376 or,if you factor in 3% inflation to get its true worth in dollars at the time of investment, it is $378. That isn't a very flash return for a life time but many would consider it fairly reasonable. The problem with KiwiSaver is the tax regime which requires you to have to earn $150 for every $100 you invest and then taxes not the money you really earned ($3 on $103) but on the whole $6. The other three is eaten up by inflation. Remember that inflation is, to a large extent, government controlled.

In case you think I am being picky, other jurisdictions have got it right. Our next door neighbours, Australia charge 15% on money its workers invest and $15% on their earnings regardless of their tax bracket. This is from their web site and they probably don't emphasize the fine print so there may be "whichevers" and "wherefores" that detract from this apparently advantageous picture. America and Britain, as far as I can work out, charge nothing on the money they invest and nothing on their earnings. I 'stand under correction' on this and would be very happy to hear comments from anyone who lives under these systems as the web sites are not that easy to follow.

The problem with KiwiSaver is not the plan itself but the government tax structure. They don't have to make it seem that we are getting something for nothing. There is a name for that. They just have to let us keep more of what we actually earn and give over on the idea that since this is a savings scheme, we really shouldn't expect a decent return for tying up a large portion of our disposable income for most of our lives. Do the maths and you will find that it is a far better investment under most economic conditions to invest a greater amount in your morgage. Calculate your net worth at 65 and this will put you far ahead of investing in KiwiSaver.

(disposable income - the income left after you pay off rent, electricity, basic food and so forth).

Tuesday, September 18, 2007

Pension Funds and Solar Panels

Some governments say that the main purpose of a pension fund is to provide for us in our retirement. They sometimes hint, that since it is a savings plan and not an investment, we shouldn't really expect much of a return (Yeah right!!!!) and should be grateful for any contributions or tax concessions they make. Since pension funds are "for our own good", lets take them at their word and see if they will "put their money where their mouth is". What about allowing us to use funds from our pension fund for putting solar water-heating panels and/or solar electric panels on our roofs or for that matter, to insulate our houses.

The oft quoted expenditure for water heating is about a third of a typical electrical bill so if we install a solar water heater, all this saved money will be available for retirement saving, making us even better off in our retirement. The typical pay back time for solar water heating is between 5 and 10 years and the earlier we install it the more we will earn. Moreover, when we retire, the children are likely out of the home so we can probably get all our hot water needs without having to use supplementary electricity. If there was ever a use of our pension money that would leave us better off in our retirement, this is it. And what about installing Solar-Electric panels. Here the benefit is even greater.

With Solar-electric, again we score well before retirement. The one time investment will pay dividends all through our life, leaving us more money from our income for saving. When we retire, with the kids out of the house and electrical demand reduced, we may even be receiving a net income from our solar panels. Our own private pension plan. Even better, since our excess generation is turning the metre backwards, we save on our tax bill. When we buy electricity, we pay GST(VAT). Since we are reducing our payments we pay less GST.

We also gain on the other end. If you sell something, you pay income tax on your earnings. Here you are simply turning the meter backwards. In so far as it is balancing your electricity use, it's neither income or expenditure so you don't pay tax on this money. Better and better.

The expense reduction I am really looking forward to, though, is when purely electrical cars with, say, a 200 km range and a reasonable price tag, come on the market. Every home will have a 'petrol station' on the roof in the form of their solar panels. The car gets plugged in and the house "fills the tank". Add solar panels to the roof and hood of the car and you could perhaps add an extra 10 to 20km of driving for a day in the sun.

A further benefit of solar electric will occur to the canny retired couple who are now at home during the day. They will be able to do their bread making, hovering, laundry etc during the day when the sun shines. This will avoid the price differential between the buying and selling price of their electricity#. Therefore it is to the advantage of the house owner to use electricity when they are generating their own. The electricity company shouldn't have it all their own way, though. A household will be producing power during the day when the electric company charge the highest rates. Their payment to you should reflect this. Also with diffuse power generation all over the country, generation will be, on average, closer to the user so line losses will be less. This should also be reflected in the payment to the domestic generator.

#There will always have to be a price differential. The power company will have to charge you more for a unit of electricity than what they pay you. After all, they must maintain the distribution network

Solar panels, whether electrical or water heating, are a true retirement saving plan but in addition they fulfil a number of national goals. These include reduction of our carbon foot print, reducing the need to build more unsightly power pylons (power generated diffusely and hence nearer to the users), reduced need to flood more river valleys, reduced negative balance of payments due to less fossil fuel imports, reduced air pollution from thermal power stations and vehicles, reduced chance of power breakdowns in times of national emergency (inter-net effect) and reduced health bills from air pollution. With such a long list of beneficial effects combined with the obvious retirement benefits, I'm sure the government will approve using pension funds for domestic solar panels. Let's see if your government is really serious when they advertise that your contribution to a pension plan is for your own good.

Sunday, September 16, 2007

I wish I'd thought of that - growing tomatoes with sea water

I wish I'd thought of that. How dumb could I be. And I was working where the desert meets the sea, I had a desert cooler cooling my apartment and..... I was growing plants in pots in the cool humidified air from the desert cooler. Talk about not connecting the dots.

It is possible, in fact not very difficult, to grow crops with no source of water except sea water or brackish water or alkali water or for that matter sewage water. You have to be in an area where the air is dry - the dryer the better, and if there is a prevailing wind you can cut your energy costs somewhat. If you want to see a far better explanation than mine, google "sea water green houses". Otherwise read on.

Water has a very high latent heat of evaporation. All this means is that it takes a lot of heat to evaporate water when compared with most other substances. The flip side of this is that if you pass dry air over water and, especially if you contrive to make the water expose lots of surface area, you cool the water and the air. You cool it a lot. I mentioned the desert cooler in my apartment.

These are simple boxes of about a metre by a metre and a meter and a half high, made of fibre glass or galvanized iron. They have louvres on all four sides. The bottom of the box is a shallow tray with a simple toilet float valve attached to the municipal water supply. This keeps the water level in the tray constant. A small centrifugal pump pumps the water from the tray and dribbles it over top of excelsior screens which are attached just inside the louvres on the three outside sides of the box. A little water is allowed to go to waste to take care of salt build up but most of the water flows down the screens back into the tray. A drum fan sucks air through the 3 screens and pushes this cooled, humidified air through the fourth side into the house or apartment. The air comes out humidified, much cooled and the water in the tray is too cold to put your hand into for very long. In fact it is a great place to keep the butter hard or the beer cold. These desert cooler boxes are hung outside the apartments in an opening in the wall so that the inner wall of the desert cooler is flush with the inside of the wall of the apartment.

Sea water greenhouses work the same way. One end of a plastic-clad tunnel house is covered in some sort of a screen that allows the outside air to pass through it and the water to dribble down it. If there is a prevailing wind, the tunnel house is aligned with the wind. Sea water or any other waste-type water is pumped to the top of the screen and allowed to dribble down to the bottom where it is collected in a trough. If there is no wind, a fan is inserted into the down-wind end to suck air through the tunnel house.  A nice touch would be to power the fan with solar panels.  More sun, more heat, more air moved.

Already conditions are far better for the plants. Under the resulting cooler, moister conditions, plants use far less water and are under less stress. However it doesn't stop here. The cold water which is caught in the trough under the screens is then pumped through a lagged (insulated) pipe to the down-wind end of the tunnel house. There it is pumped through a condenser. For the sake of illustration, think of a car radiator with the water being pumped through just where water normally goes through the radiator and the cool moist air from inside the tunnel house passing through the condenser where the air normally goes through a car radiator. The condensers aren't actually built this way but this is just to give you the idea.  Fresh water condenses out and drips down into a second trough. This fresh water is used to water the plants in the green house.

Of course, the plants also transpire moisture into the air stream which is available for condensing as well. If you are in the lucky situation that your feed water to the green house is cold, you can also use that for condensing fresh water out of the air flow before it goes to the upwind screens. Cold sea water exists, for instance, beside deserts which are adjacent to the many upwelling areas of the world. It is also available on volcanic islands in the tropics where the bottom slope of the ocean is so steep that it is practical to put a pipe to below the thermocline.   Cold water is typically found at about 500m depth in tropical oceans.

You can now use the fresh water you produce in a hydroponics system, recirculating the nutrient water either in a batch form or with nutrient make up, or it can be used with a soil growing system with a plastic liner below collecting excess water. It can also be used in an open system allowing excess fresh water, lightly laced with nutrients, to seep into the ground to replenish the water table. In desert areas, such a flow of fresh water into the water table has been seen to make the area around the green house or areas down slope begin to bloom with whatever seeds are in the soil or with whatever the farmer decides to plant.

Very long term, such a farm using alkali ground water and returning fresher water to the ground would start to sweeten the ground water in the water table as it removes alkali salts. The salty water coming out of this system can either be piped to the sea or to ponds to evaporate.  In this case, there is the possibility of harvesting various salts as  by-products.

As I said, I wish I had thought of this system. Genius is the recognition of the obvious which no one else sees. I certainly wasn't showing any. I would have thought that Australia with its present crippling drought and ditto, California, would be beating a path to the door of the developers of this system but probably isn't. After all, genius is being able to see the obvious. 

Wednesday, September 12, 2007

Fertilizing New Zealand - the natural way

Prior to the invasion of the first humans, New Zealand apparently used to receive a constant application of fertilizer. This fertilizer was better in quality and larger in quantity, than what all our farmers now apply to our pastures. It would be possible to get the system operational again but it would take some work.

Before humans arrived, New Zealand had a fauna dominated by birds. The only mammals in New Zealand were Bats. We are all familiar with the stories of the giant flightless Moas. However another set of less publicised birds was arguably more influential on the environment. These were the sea birds. The various species, including our favorite 'mutton bird' fed at sea, and nested on land. Some of them, like the Mutton Bird dug out burrows for a nest where they raised their chicks. Without ground predators the sea birds could nest anywhere between the coast and as far as they could fly with their load of stomach-stored-fish to feed their young. In south Island, the remains of nests have been found as far as the foot hills of the Southern Alps. A remnant colony of nesting sea birds still exists high on the mountains of Kaikura. So what destroyed this system.

The obvious candidate is man who, when he arrived, found a rich, easily captured source of food in the nests of the burrowing sea birds. However, an animal he brought with him was probably an even bigger destroyer of this ecology. When Polynesians traveled in their ocean-going canoes, they often brought along the Pacific Rat. Rats are very adaptable and provided a good source of human food once they become established on an new island. Fish and oysters are great food but every once in a while one wants some real meat. Traces of the Polynesian rat have been found in Moa swamps from long before it was believed that the first Polynesians reached New Zealand. It is possible that a canoe of men-only arrived much earlier than the accepted first-arrival date, or that some natural disaster such as the explosion of Lake Tapo wiped out early settlements. Whatever the case, the rat became established and preyed on the young of the nesting sea birds. Unused to predators, the sea birds never had a chance. If the Polynesian rat wasn't enough, as soon as Cook arrived, the European rat, an even more destructive beast, was introduced and quickly spread.

Before their demise, sea birds deposited large quantities of Guano on the land. Guano is not only rich in the major essential elements but also in all the trace elements needed by plants. Any home farmer knows that if he manages to cage a bag of guano, he puts it under lock and key and doles it out with a teaspoon to his favorite plants. Its effects on plants are legendary.

There are a few systems in nature that reverse the constant flow of nutrients from the land down to the sea, The salmon of North America are one and the migration of eels another. However, the system that existed in New Zealand before the invasion of humans dwarfed these nutrient flows by a several of orders of magnitude. It has been estimated that the quantity of nutrients spread on the land by the sea birds exceeded the amount of fertilizer now applied by all our farmers and it was of a much higher quality.

As an aside, where do our fertilizers come from. Much of the phosphate we have used in the past came from Pacific Islands, notably in Kiribati, destroying the island in the process and along with it the life of the people that lived there. (A Pattern of Islands by Arthur Grimble). There is now talk about scraping off the little bit that remains. The phosphate deposits on the islands were probably the guano deposits from ages of sea birds. Over time guano looses its nitrogenous content leaving behind mainly phosphate. We have mined large parts of these islands down to bed rock, leaving them virtually uninhabitable.

Our nitrogen we obtain mainly by fixing atmospheric nitrogen into compounds (Haber process) and putting it on our fields. There are some ecologists who believe that the resulting warping of the nitrogen cycle - favouring nitrification over denitrification - may pose a greater threat to our world in the long run than our release of geologically sequestered Carbon.

So how could we get the sea birds rather than top dressing planes to fertilize New Zealand again. How could we utilize nutrients from the sea instead of destroying peoples homes and unbalancing the nitrogen cycle.

Fortunately, we don't have to reinvent the wheel. The bones of the system already exist in Namibia.  South western Africa is one of the typical upwelling areas of the world with a desert on land and an incredibly rich marine life offshore. Sea birds abound in this rich area and any little island that Africa's predators can't reach is populated by masses of squabbling birds, all after nesting sites. Because of the lack of rain, the guano builds up and this renewable resource has been collected for decades for fertilizer. However, the African guano companies realized that they could increase their output.

With no lack of fish in the sea, the main limit to the sea bird population is the lack of nesting sites. The guano companies solved the problem by driving pilings into the bottom of some of their shallow bays and building platforms on top of them. This isn't much help to the burrowing sea birds but for the shags, cormorants, gulls and so forth, it provides much needed additional housing. On some of the platforms, a little bob-cat type front-end-loader is left permanently and every year or two they simply scrape off the guano and load it into a barge tied up along side. The question is, how could we best adapt this system to New Zealand.

The first thing to do is to see if it will actually work here. Will a platform set up in a shallow bay actually become populated with nesting sea birds. An ideal site would be near the Marine Laboratory in Portobello where it is out of the reach of storm waves and could be monitored by the laboratory staff. This location has the added advantage of being close to the Circumpolar Subtropical Convergence, an area rich in marine life. Of course the guano might not remain on the platform due to our relatively high rainfall but that is OK. Our initial aim is to see if an added "housing facility" would encourage the nesting of sea birds. Work could even be done to see if burrowing sea birds could somehow be induced to nest on the platform, possibly by providing them with artificial burrows. Then in addition to guano, we might develop a source of mutton birds.

If successful, the next step would be to set up a similar platform somewhere nearby on land. Here the pilings would have to exclude climbing predators such as possums, stoats, cats and rats. It might be sufficient to use the possum guards that we use on many of our wooden power poles or one might need to use steel or cement pilings. This next stage would prove whether or not sea birds would nest on such a platform situated over land. It would also test predator exclusion and would provide more experience with the system.

The third stage would be to put platforms further and further inland and ask a range of questions.

* How is the dung distributed. ( Do the adult birds deposit Guano only when at rest on the platforms or do they deposit dung as they fly.)
* How much Guano is deposited per nest and per area of platform.
* Is guano distribution determined by the distance from the platform to the sea.
* What is the guano composition in relation to plant needs.
* Is the area around the platform so over-supplied with nutrients that it becomes sterile.
* Can the guano be profitably harvested or is it all washed off the platform by the rain. Does this vary at different geographical locations around New Zealand.
* If guano can be harvested what area of platform would be needed to make a farm of a given area fertilizer-independent.
* Can the platforms be modified for mutton bird nesting without interfering with the fertilizer collecting function.
* How large a system would be needed to start up a viable mutton bird business.
* Are there ways of encouraging one species of bird over another.
* How are the nutrients from the platform spread naturally over an area (plants fertilized by the Guano near the platforms, eaten by grazers who spread their dung further afield)
* Are there low cost ways of spreading the dung to lower areas on the farm (via gravity fed water from a pond into which the guano rain-wash is flowing for instance)
* Is there any damage to lambs at lambing time from any of the occupants of the platforms
* Is there any benefit to sheep or cattle fed on Guano-fertilized-grass. (fecundity, birth success, longevity, freedom from disease) when compared with livestock living on grass which is conventionally fertilized.
* Will Guano compensate for the soon-to-be lack of clover (veroa is on the way down South Island)
* Can Selenium prills be dispensed with when Guano is used.
* Can B12 injections be dispensed with when Guano is used
* Is there any difference in the de-worming necessary when sheep or cattle feed on Guano-fertilized grass.

Sustainability seems to be the buzz word in Ecology today and with good reason. We are a plague on the earth and our sheer numbers and gargantuan amount of waste are trashing the ecosystem we depend on. Any steps we can take to be more in harmony with natural cycles will help to reduce our foot print.

At Present we fix atmospheric nitrogen and flush much of it down our rivers, causing eutrophication in lakes and even in large areas of the sea where the rivers debouch. A system which reduces the artificial fixing of nitrogen and simply picks nitrogen up from the sea and brings it back to the land has to be an improvement. A fertilizer which obviates the need to destroy populated islands has to be an improvement.   If a fertilizer which has a much better mineral balance can be obtained at the same time and if it can reduce the fertilizer costs to the farmer, better still.