The whole team spend a good part of the day going through the equipment for Saya 2002, which we've stashed in a workspace kindly loaned by the long-suffering Seychelles Sail Training Association (a great outfit, getting lots of kids out on the water).
Frank, who purchased and shipped it all from Germany, has not stinted on top quality materials. There's a large consignment on top of the range Siemens Solar Panels for power generation at Saya. Angle irons, drills, solders, scores of other tools. Complete sets of dive equipment. Everything is checked and re-checked.
The Toyota generator that powers an Oceanus Air Compressor is the devil's own business to start. The fault turns out to an electrical connection that has vibrated loosed during transit. The other small generator, a Briggs & Stratton from Britain, starts first time: "The best engines in the world", says Hartmut.
Everybody works very hard all afternoon, and there's a real feeling of satisfaction in actually doing something.
Later Tom and Gabriel, known as Gaby, talk about one of the major reasons for coral death. In recent years, many of the world's reefs have been smothered by a huge assault from algae. Why? There are three hypotheses: over-extraction by humans of the herbivorous fish which eat the algae; a crash in sea urchin populations (they also eat algae); and excessive nutrients loads in the water which favour algae over coral (eutrophication).
Tom and Gaby think the first and second hypotheses are quite wrong. But orthodoxy will not accept this, and the result is continuation of inappropriate policies at the expense of measures that could help.
On the first hypothesis (lack of fish to graze algae) Tom says: "All over the world I've observed that wherever algae are abundant there are large numbers of herbivorous fish. In other words, fish numbers increase with algal abundance, but do not limit the algae".
"Take the case of the Seychelles. Simon Jennings, now based I think in Lowestoft, England, did high quality survey of fish distribution on the reefs here. He found that planktavores [fish that eat plankton] dominate the outer island reefs just as they do elsewhere in the Indian Ocean, but around Mahe and the other inhabited islands in the central group herbivorous (algal eating) fish dominate.
"Simon did remarkable work characterizing the physical parameters within which different species and groups of species flourished. But he did not take account of proximity to nutrient sources. If you look at his data the correlation is obvious. I understand how algae arrange themselves along nutrient gradients. This is due to nutrients flowing in from rivers and sewage outfall. Both toxic [kinds that fish don't eat] and non-toxic types of algae are growing out of control.
"In Jamaica the fishery has been based almost entirely on herbivorous fish since the 1960s. Peter [Goreau] and I watched all the carnivorous fish [e.g. groupers, jacks, snappers] being wiped out in our lifetimes. No carnivorous fish, the preferred eating, reach reproductive age. There is no part of the coastline that is not scoured by spear-fishermen every single day, barring very rough weather". Herbivorous fish dominate, but algae is everywhere.
The second hypothesis is that crashes in the numbers of sea urchins (diadema sp. - the long black spiny kinds) that prey on algae allowed an explosion of algae populations. In the 1980s the urchins went through two massive die offs (well over 95% mortality) throughout the Caribbean, for example.
Tom points to contrary evidence. "When the sea urchins disappeared in the Caribbean there's no blip in the rate of algae increase. The urchins did not affect the fundamental dynamics of the population... It's claimed [that since then] urchins have not come back. But that's not true. You can see in many places, Panama for example, that diadema is back in huge quantities and yet the algae are still growing and growing. "The urchins are much bigger than they used to be, and they just sit there, like cows in a stall, eating a little ring of algae around them". Before, urchins used to have to cover quite large distances to find algae.
"Here at St Anne's [Seychelles] where we're building a small geodesic structure you have to be very careful of diadema. They're present in huge numbers, but however many there are they can't control the algae". Clearly urchins are not a limiting factor on algae.
The third hypothesis is nutrients. "Algae increase as nutrients increase", says Tom. "Of course, you would expect natural increases in nutrient levels from time to time - for example from upwelling of nutrient-rich waters. You will see natural eutrophication around bird nesting islands. But in natural systems you would expect to see fluctuation. Instead, what we have is a steady linear increase with time. This must be anthropogenic [man-made]".
"In the '60s I was collecting algae for Prof. Francis Stewart of Cornell University [the first man to clone a plant cell]. We were diving every weekend all round the island of Jamaica, and at that time we had to come to Kingston Harbour to find algae in good quantities. Gradually, the algae spread.
"I watched this happen around every [human] population centre through the '60s, the '70s, the '80s and the '90s. At first you could see every source until they all merged into one. The last healthy coral in Jamaica went in the '90s. There's nothing left except algae. Swimming down the gradient you can see them go from green to red to brown, zoned by nutrient tolerance".
Some of the most important work to support the third hypothesis was done Brian Lapointe, says Tom. "He went to a bird rookery island on Belize reef. All the mangroves were white [from guano]. The water beneath was green [from eutrophication]. But further out you could see coral [in clear blue water].
"Brian measured the nutrient gradient. He found the transition point - the critical level for corals - was 1 micro-mole per litre of Nitrogen and 0.1 micro-mole per litre of Phosphorous. That is an order of magnitude or less than for any other marine ecosystem". In other words, corals, one of the richest ecosystems on Earth, thrive in tropical waters which are naturally very low in nutrients.
At around the time that Brian Lapointe was doing this research in Belize, another researcher named Peter Bell was, independently and without knowledge of Lapointe's findings, doing very similar research on nutrient concentrations on the algae-infested reefs in Queensland, Australia. "He came up with exact same numbers [and critical thresholds] as Brian", says Tom. "I put them in touch, and they started working together".
"Brian and Peter were ridiculed... The scientific literature is riddled with papers concluding that nutrients cannot be a critical factor. This is because the authors use as their baseline other ecosystems [in higher latitudes] where nutrient levels are orders of magnitude higher...People said nutrients could not possibly be affecting the reefs.
"The institutions that managed the Florida reefs and the Great Barrier Reef in Australia [echoing the Queensland sugar barons. They said there could not possibly be mismanagement of nutrients [sewage and agricultural fertilizers] on land, affecting the reefs. In Australia they dismissed complaints by aboriginals who saw a major food source destroyed as 'anecdotal'. So the funding agencies would not help [Brian Lapointe and Peter Bell]".
"Instead, these agencies spent large amounts of money to try to disprove their work. At Lizard Island in Australia they poured nutrients onto a place that was already an algae dominated ecosystem! Obviously, a total waste of time.
"In Florida they put fertilizer sticks of the kind you buy in K-Mart to fertilize lawns into areas already dominated by algae to see what would happen. They found after a few days rings of dead algae around the fertilizer sticks. They had not realized that the sticks contained a slow chlorine release which is put in the sticks to prevent them becoming covered gunk in the hot American summer air! You have to laugh sometimes at the orthodoxy that is accepted in this field, and the idiotic, utterly non-scientific means used to 'prove' it".
In Kuna Yala [Panama], US researchers concluded from a 15 year study that [exponential] algal growth could not be due to nutrients because the waters were 'clean'. But they did not even measure nutrients levels, even though you can see that the rapidly expanding population disposes of all their waste directly into the lagoon".
"For me it's crystal clear that nutrient levels govern algae. Brian and I have measured this in many places. We have been able to show the growth rate of alga directly proportional to nutrient availability [what kinds grow depend on ratio of N to P].
But this has been missed by majority of researchers. It is difficult to measure nutrient levels. Instead, they continue to advance a dangerous fallacy. Their prescription is reduce fishing. But the fishermen are not the cause. They are the among the first to suffer. The result is false social policy that will not work. For coral areas you need tertiary level sewage treatment everywhere, not just a little cosmetic work for the rich".
Gaby says: "Flying here up from Panama to Miami on my way here, I saw a fifteen hundred mile long algal bloom. I nearly cried. It's awful. I knew that there was trouble but it's another thing to actually see it from the airplane".
"The whole Caribbean is going eutrophic" says Tom. "Even on the outermost reefs at Kuna Yala [Panama] there is hardly any coral left. In Mexico I see the same pattern: almost all the outer reefs are gone. Reefs are the ultimate downstream ecosystem".
Caspar Henderson
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