Conservation comment

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In hindsight I realised that we had not given a lot of time to the conservation aspect of our trip and the original reason for heading to Madagascar - to join the Blue Ventures Dive Project. So just in case you think we spent all our time partying and dressing up as superheroes when we were there, here are some of the stories and science behind the problems that the Blue Ventures team were and still are trying to tackle, that unfortunately are not restricted to Madagascar.


If you’re into using Google Earth then have a look at where we were living and working, a couple of hundred kilometres north of Tulear on the west coast of Madagascar. Type in the longitude and latitude of 22 04.2664' S, 43 14.0480' E and you should see a small semicircular bay (Half Moon Beach) with a few huts on the cliff behind it (our homes for 6 weeks), the nearby village of Andavadoake just to the north along the curving beach and the reefs that we dived just offshore.



Before we get into the work we helped with out there, here are with few words about what reefs are, how they work, how they are damaged and the reasons why we should be concerned for their health.


WHAT IS A CORAL REEF?


Mistaken for plants by the ancient Greeks, corals are actually animals, related to anemones and jellyfish. The reef itself is a limestone or calcium carbonate ‘skeleton’ that houses living animals called polyps, with the structure encasing each new polyp as it grows. Each polyp has a skeleton cup, tentacles with stinging cells, a mouth and a stomach. One way the coral obtains nourishment is by these tiny tentacles snatching at passing plankton for food, but for most of their requirements, reef-building corals have devised a much more ingenious method to get fed. In fact, the reef obtains most of its energy through photosynthesis, but it is not actually the coral polyps that photosynthesize, but single-celled algae called zooxanthellae. In return for a safe sunny home, the zooxanthellae eat the nitrogen waste that the coral produces (nitrogen is very good for algal growth) and, like all plants, the algae turns sunlight into excess organic nutrients by the process of photosynthesis - these sugars are then used by the polyps. This relationship is paramount to coral growth as the food produced by the zooxanthellae make up to 98 per cent of the coral's food and without them development would be too slow to form large reefs. So, without having to do any work at all, the coral is kept clean and well fed, and the zooxanthellae with their brilliant reds, oranges and browns give corals their colour and most importantly keep divers happy.

WHERE DO THEY GROW?

I guess we all know that coral reefs need warm, shallow water to grow, but somewhat surprisingly, because of this symbiotic relationship, coral reefs grow much faster in nutrient POOR and therefore clear water, which admits more sunlight thus improving photosynthesis in an area termed the photic zone. In addition to depth and water condition, the wave action has to be significant enough to deliver enough food and oxygen, yet not so strong that it tears the reef apart. The latter condition is not always true, in Madagascar during early 2006 a particularly bad cyclone took its toll on some of the reef, although a large proportion survived relatively intact. Many other organisms living in the reef community contribute their skeletal calcium carbonate to improve the structural integrity of the reef. For example, Crystal Coralline Algae (CCA) is a type of coral that grows as a layer over the surface of existing coral and is often found where the reef is subject to the greatest wave action. It can appear like pink icing sugar and was one of the coral types that we were required to identify and record as a measure of reef health in Madagascar. In addition to wave action, coral reefs do suffer some other ‘natural’ damage from grazing fish nibbling at the reef, sea urchins, sponges and other organisms breaking down the coral skeletons into fragments that settle into spaces in the reef structure. This process also produces that powdery fine white sand found on tropical beaches, which is actually ground up coral. Maybe you will look at the beach in a different light next time you are soaking up the rays and remember that it has been excreted by a parrot fish! In general these natural actions don’t significantly affect reef health, one exception that you may have heard about is the ‘Crown of Thorns’ starfish, a rather nasty chap with a habit of eating everything in its path and replicating when chopped in half by well meaning divers. More about them in the section about reef threats below.


WHY SHOULD WE WORRY ABOUT THE REEFS - WHY DO WE NEED THEM?

There are plenty of reasons why we should be concerned for reef health.

Biodiversity and fishstocks

The most obvious function of a reef is the protection and shelter they provide for many different species of fish and these amazing breeding grounds are sometimes referred to as the "rainforests of the sea,". Corals also provide a source of nitrogen and other nutrients essential for the food chain. Not only do the animals that depend on reefs increase the diversity of our world, but together with molluscs they feed millions of people every year.

Carbon dioxide

Corals are very important in controlling how much carbon dioxide is in the ocean water. They are classified as marine calcifiers and the polyps turn the carbon dioxide in the water into a limestone. Without coral, the amount of carbon dioxide in the water would rise dramatically, having an effect on all living things on earth. The problem is compounded by the ever increasing emissions of carbon dioxide from our everyday activities that are so well documented.

Scientific research

Just like the tropical rainforests, this biodiversity may be the source of medicines, chemicals or other resources that haven't even been discovered yet.

Erosion

Reefs offer physical protection to coasts from strong currents and waves by slowing down the water before it gets to the shore, hence the term barrier reef. Many islands and coasts would be eroded away without the presence of their surrounding reefs.

Tourism

Coral reefs are beautiful places and can provide income to many otherwise poor countries around the world. At face value this may seem a little ‘money focused’, but we are seeing more and more examples around the world that when done properly this ‘ecotourism’ is providing a viable alternative to otherwise destructive activities. The African big game parks are an easy example, where nowadays people pay big bucks to shoot animals with their cameras rather than guns. I say ‘when done properly’ due to the number of supposed ‘ecotours’ that we have seen travelling that are simply jumping on the bandwagon and using the term for its marketing potential and not with any thought for conservation. I saw a recent advert for a helicopter ecotour around one of New Zealand’s national parks, which involved nothing but blasting around burning a few hundred litres of Avgas, just because it was easier than walking. I’m not suggesting such activities should be banned, (I’d love to have a helicopter flight!) just that regulation of what can be described as an ecological trip should be tightened. Having said that maybe if it gets people into the countryside and more aware of what’s out there then it is better than nothing. Anyway I digress..


WHY ARE THE REEFS IN DANGER?

Pollution and irresponsible development

Reefs are great indicators of the mistakes we are making on land and the levels of pollution being fed into our seas. Human impacts include industrial pollution, deforestation, irresponsible land development and overuse of fertilisers. Human effluents pollute the reef and its fish, hence entering the food chain and therefore us (particularly via filter-feeders like oysters). Poor land management can produce vast quantities of sediment and nutrient runoff from farming, roads and other construction, which reduce water clarity and retard reef growth. Fertilizers, often in combination with nutrients from sewage and nitrogen gases from traffic and industrial fumes falling on coastal water from the air, trigger increased growth of tiny marine organisms called phytoplankton, creating so-called ‘algal blooms’. The rapid growth and decomposition of these organisms depletes oxygen levels in the sea-water making it difficult for fish, oysters, other marine creatures and important habitats such as sea grass beds to survive. Experts claim that the number and size of deoxygenated areas, sometimes known as ‘deadzones’ is on the rise, with the total number detected rising every decade since the 1970s. They are warning that these areas are fast becoming major threats to fish stocks and thus to the people who depend upon fisheries for food and a livelihood.

As our activities apply increasing pressure on the reef, there has been a concurrent depletion of once prolific mangrove forests which have the ability to absorb nutrients and trap sediment. The loss of these wetlands and mangroves are considered to be significant factors affecting water quality on inshore reefs. They also provide the perfect spawning grounds for juvenile fish, that mature within the protection of their roots and hence the preservation of these areas is of major importance to fish stocks.

Although earlier I mentioned the Crown-of-Thorns as a natural predator of coral, populations of the starfish have increased since the 1970s and large outbreaks of these starfish are believed to be caused by agricultural runoff causing the algal blooms mentioned above. The connection lies probably in the increased amount of algae supplying coral polyps with large amounts of food, thus reducing their normal levels of predation on the starfish's eggs. Therefore this species is at least partly responsible for much loss of coral, particularly on the Great Barrier Reef in Australia however this has only happened with human encouragement. Few animals in the sea are willing to attack the spiny and toxic crown-of-thorns starfish, but surprisingly, some sea creatures prey on them. Notable predators include the Giant Triton, (one of the invertebrates that we were tasked with recording during research dives at Blue Ventures), a species of shrimp, a species of worm and various reef fish (especially the Humphead wrasse) which feed on larvae or small adults. It is quite likely that the decline of these predators (through overharvesting, pollution, etc.) has been an additional factor in the rise of the starfish population, making outbreaks more likely to occur.


Rising sea temperatures

Over the past one hundred years, the temperature of sea water in many tropical areas has been rising. For example, the Australian Institute of Marine Science has collated data showing that 2002 was the warmest year for water temperatures off northeast Australia since 1870. And there are predictions of a sea temperature rise of up to 1ºC within 50 years. Rising water temperatures block the photosynthetic reaction that converts carbon dioxide into sugar. This results in a build-up of products that poison the zooxanthellae. To save itself, the coral spits out the zooxanthellae and some of its own tissue, leaving the coral a bleached white. The bleached coral can recover, but only if cooler water temperatures return and the algae are able to grow again. Without the zooxanthellae, the coral slowly starves to death.


Having said all that, I have just read an article posted on www.aboutmyplanet.com, which puts an interesting twist on the coral bleaching issue. I thought of re-writing it in my own words but that seemed like a waste of time and probably counterproductive as it was already so well written. Anyway, thanks to the author Brooke Olive who I hope won’t mind me quoting her directly and spreading the word.

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Coral Bleaching: Precursor of Death or Survival Tactic? By B.Olive

Coral reefs may appear to be durable and impervious to rough conditions, but are in fact very sensitive to environmental stresses and human disturbance. Reefs are actually highly evolved eco-systems and rely on certain conditions to preserve themselves. Anything that may stress the reef, or a combination of stress factors, can result in coral bleaching. Changes in conditions such as temperature, pollution in the form of herbicides and oil, even exposure to the atmosphere during sudden low tides can cause bleaching. The bleaching is a result of the loss of a certain algae that leaves the reef unable to produce energy from sunlight.

Coral bleaching has increased worldwide in the past few decades and has been linked to changes in global temperatures, as increased sea temperatures and ozone depletion result in bleaching; however, new studies have shown that the bleaching may be just a survival tactic and that previous theories of reef extinction were based on the fact that bleaching usually precedes coral death and loss of the reef as well.

Scientist Andrew C. Baker of the New York Aquarium found that after undergoing extreme environmental change, 'bleached' corals were more likely to survive. Bleaching, then, may just be part of a coral's capability to endure severe conditions. More studies conducted in Edinburgh show that coral reefs may just be flexible enough to survive. Geo-chemist Malcolm McCulloch found that in past eras of warm temperatures and high sea levels, reefs flourished. This survival is based on the fact that rising sea levels afford more space to reefs, and subtropical areas can experience reef growth due to warmer sea temperatures. McCulloch explains that, as long as the rate of warming is no faster than they (the reefs) can cope with and assuming that our pollution doesn't kill them off first, then coral reefs will do well in warmer weather.

So global warming may have less of an impact than originally thought. It may in fact benefit the reef. Coral that has been bleached (or has lost its original algae) can attract different species of algae that are more suited to the new conditions. Baker, from the N.Y. Aquarium, discovered this after transplanting dozens of coral colonies into deeper and shallower waters to simulate climate change with falling and rising sea levels. Eleven of these colonies had notable bleaching, and all survived the year-long follow up period. The coral colonies that did not shed the original algae in the transplant process did, however, eventually die.

The focus then should not be on the bleaching of coral reefs due to global warming but on the other stress factors that can cause ruin to these vital eco-systems. Focusing instead on human causes such as pollution and direct interference can give reefs the best outcome in the long run. Healthy reefs will be better able to adapt and survive the effects of global warming.

Apart from controlling the direct human stresses on the reef, being aware that it can take hundreds of years for the ocean to adjust to climate change and therefore display ultimate results can also be advantageous. The fact that reefs may well be very different from the ones we have now does not imply that they will cease to exist altogether, or that they will not support marine life and the smaller eco-systems that they do now. It should be a great comfort to many that the reefs will, like animals and plants have done for eons, change and adapt accordingly, in order to survive.

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So there’s something to think about…. I also quite like this response that the article got from someone:

….that's interesting - it's like saying, "if we cut off your arms if doesn't mean you'll die, it just means you can find a new exciting way to eat your pasta. I guess I won't worry about losing my arms, then...”

And as Brooke concludes, nature has a way of adapting and surviving change, so we aren’t talking about the ultimate destruction of the planet, but our impact on its direction of development. Essentially we seem to be forcing it to evolve in a way that won’t necessarily suit us humans too well in the not so distant future.

In summary, I think we can stick to the basic premise that when coral reefs die, fish populations reduce or disappear and unprotected by these natural breakwaters, fragile land areas become vulnerable to erosion, saltwater intrusion and destruction from waves. The facts are that for already damaged reef, regeneration is very slow taking several decades, even under ideal conditions and according to the ‘experts’, if destruction continues increasing at the current rate, 70% of the world’s coral reefs will have disappeared within 50 years.


So that was the intro.... it got a bit more involved than I thought it would and I still haven’t covered all the issues, arguments and influences on the ocean environment, but heh this is a blog not a thesis. Let’s move onto how the conservation movement is trying to help the situation and specifically what we actually did at Blue Ventures.



There are two aspects to conserving a natural resource, the obvious one being to reduce damage to the environment that houses the natural resource (in our case a coral reef), but at the same time the aim should also be to reduce the use of the resource in the first place (in this case catch less fish). It’s like insulating houses, turning off appliances and changing to energy efficient lightbulbs, rather than just saying we need another nuclear power station or 4,500,000 wind turbines. It doesn’t make the fundamental problem go away, but it does reduce the strain on the system that you are trying to fix.

One of the reasons that the reef system in the Andavadoake area was highlighted as ‘at risk’, was the shift from a subsistence existence where fishermen only caught what they needed, to a trading culture where they were catching as much as they could to sell to passing wholesalers and larger factory style ships were beginning to trawl the waters. So, in addition to the detrimental affects suffered by many of the world’s coral reefs (as mentioned in the intro), overfishing was having an ever increasing impact on the huge reef system down the west coast of Madagascar.

Now, given that Andavadoake along with every other coastal village relied on fishing for their livelihood, it might seem a little outrageous that anyone, particularly a bunch of foreigners should be considering trying to control what the locals catch. Well on the face of it, it does seem rather dictatorial - but for once this foreign intervention is actually designed to benefit Madagascans in the long run unlike numerous previous commercial enterprises that have raped many of its other natural resources. Justifiably there is a degree of mistrust to be overcome and it is fair to say that this is one of the main hurdles facing projects such as these when trying to explain the reasons for protection measures, fishing restrictions and ultimately show that there is something in it for them.

Understandably as one of the poorest African countries, conservation isn’t a particularly high priority, whereas ensuring that they continue to return home at night with enough fish to eat and/or sell is. So there lies the main technique for pushing the environmental protection of the water, explain the consequences if you don’t or more precisely demonstrate the consequences if you do and the positive effects this can bring about. It is well known that if you manage what you catch in terms of numbers of fish, declaring minimum fish sizes to avoid catching juveniles and dedicating areas as ‘no-take zones’ to act as safe breeding grounds, then fish stocks can be maintained to provide a sustainable resource. To demonstrate the ideas of fisheries management BV chose the octopus because after remaining quite small for the first few months of their lives, these animals mature very quickly increasing rapidly in size. BV got the fishermen to agree on not taking any octopus in an area for 6 months and the end of this closure period saw people coming from villages far and wide to attend the open day when octopus fishing restarted. Without the young being taken when they were a few weeks or months old, the octopus numbers had swelled and the average size increased hugely. The event was a great success as people saw with their own eyes the largest catch, of the biggest octopus anyone could remember.

The octopus trial was the start of introducing the idea of no-take zones to allow fish species to recover, but the next stage and BV’s main aim was to create an official Marine Protected Area or MPA that would provide the structure for identifying the restrictions required to preserve and manage a much larger area. An MPA is a common term across the world meaning an area of ocean with increased levels of control and therefore protection; the watery equivalent of a nature reserve or national park. The process of setting this up is an ongoing one which we were involved in by visiting local villages, meeting with the elders and diving sites identified by fishermen as good fishing spots. If the site was deemed to be a significant habitat for fish then the area would be included in the MPA plan. By creating a patchwork of protected sites across a local coastal region fish stocks could be protected, whilst still providing sufficient fishing areas. Good inshore fishing sites should always be around a reef, but the local tipoff’s did lead to some uninspiring dives, where we dropped down onto nothing but sand.... some villages were obviously less convinced than others about the scheme!

To record what was being caught we would hold regular ‘Fish Monitoring’ sessions, where the fish in the bottom of every returning pirogue were identified, measured and counted, along with the method of fishing (net, line, spear etc), location and the fisherman’s details. This was great fun with the local women helping to name the catch using some well worn and rather smelly fish ID books. The experience was also a little harrowing at times, since there was no species that were safe in the local water. Beautiful tropical fish with hardly an ounce of flesh on them would lie gasping in the boats, sea-horses, angelfish, butterflyfish, puffers..you name it. Having said that it’s a great way to improve your identification skills when the fish aren’t 5m away swimming in the opposite direction!

The most striking evidence of a decline of species in the area were stories regarding shark populations. Only a couple of generations ago, people would not let their kids swim off the beach due to the numbers of sharks around - nowadays in 6 weeks of diving we didn’t see one shark. This is of course due to the specific practise of catching sharks for their fins, these are generally cut off with the fish alive and the carcass discarded because they take up too much room in the boat. Sold for a few dollars each by locals, this apparent delicacy would end up in Asia exchanging hands for hundreds of dollars a kilo. I may have mentioned it before, but the documentary film ‘Shark Fin Soup’ is a real eye-opener if you are interested.


The ‘everday’ reef dives that BV carry out consist of monitoring an extensive range of existing dive sites and recording the fish and coral species present. The long term analysis of this information provides the basis for understanding the health of the reef and whether it is in decline or not and gives a good view of where particular species of fish live. There were about 10 regular dive sites each with a set of 10 fixed transects, where each transect is identified by 2 stakes in the coral 10m apart.


First job on a dive was to find and identify the stakes/transect (easier said than done), a tape measure was then stretched between them and the following datasets recorded. The first was the Point Intersect Transect or PIT which involved moving slowly along the tape identifying the hard and soft coral types every 20cm directly beneath the tape. The second was the Invertebrate belt or IB, where swimming along the tape again the presence of a number of specific invertebrates found a metre either side of the tape was recorded.

The invertebrates in question were:

Crown of thorns starfish
Triton shell
Cowry shell
Strephus Urchin
Thrix Urchin
Diadema Urchin
Coral recruits

The last item on the list here ‘coral recruits’ is not an invertebrate but a small patch of new coral growth indicating reef recover or development. Doing PIT’s and IB’s was great for improving your buoyancy and control as you tried to hover just over the tape writing legibly, whilst being washed around by the swell.


A ‘fishbelt’ would also be performed on the same reef, but along somewhat arbitrary 20m paths covering the tops and sides of a reef. After the tape had been laid by attaching it to coral, we would retire to a safe distance for 5 minutes and allow the fish to settle again. We would then return and slowly swim the length of the tape, identifying the species and numbers of fish that we saw within 5m square box (2.5m either side of the tape and 5m up).


As you can imagine there was quite a lot of information to absorb in terms of fish species and benthic (anything that grows/lives on the seafloor) before we could be of any use to the project and this education took up a considerable amount of our time. We were given about 150 species of fish to learn with the aid of books, amusing acronyms, in-water point-outs by the scientists and photo’s on computer. We had regular tests to see how we were doing, whether we were able to produce reliable data and ready to be let loose on the ‘science dives’. After a successful computer test, two of us would accompany a scientist on a dive, swimming around and hopefully identifying either 20 Benthic life-forms or 30 fish species. I can tell you identifying a fish swimming off into the murk can be a little tricky, not to mention the juveniles that look nothing like the adults and the spotted varieties that have no spots when they are mature etc...etc.. The most frustrating thing was during an in-water test when you would swim by fish that you knew and you’d will your examiner to point at it.... of course they knew it was an easy one and would move on to find something a bit more challenging! It was certainly a bit of a struggle and we all had a few low points, but both Lexa and I did manage to avoid being classed as ‘Benthic and/or fish-disabled’, the phrases used to describing those who had failed too many times!


All this data was collated, helping to provide a baseline for the continued monitoring of reef health and background to support the set up of an MPA. Because we’ve been on the road for the last year we haven’t been able to keep up to date with BV’s progress very well, although we do know that the work continues and is being recognised internationally by the UN and international conservation organisations. We believe that Blue Ventures scientists will present the findings of the dive surveys at a meeting in Madagascar this October, with the hope that the data will be used by the government in its plan to expand the amount of protected areas in Madagascar, including increasing the total size of the country’s protected marine habitats from 2,000 square kilometres to 10,000 square kilometres.


In addition to the more localised affects of overfishing that we were targeting and the damage caused by recent peaks in sea temperatures, the reefs off Madagascar’s coast continue to be threatened by an increasing amount of sediment runoff. As I have mentioned in previous blogs, the country’s forests have been decimated and continue to be felled and burnt, leaving vast areas of unstable bare ground that is easily eroded and carried by rivers to the sea. When I last looked at the Google Earth satellite images it was easy to see huge plumes of material washing out to sea from the main rivers on the west coast. This material is deposited on the reef and reduces water clarity and therefore the reef’s ability to photosynthesise.


Outside of the coral reef and fish management activities, BV have also been working to develop alternative and sustainable incomes - such as ecotourism to assist local villages that are currently dependent on these dwindling marine resources. Just before we arrived in Andavadoake, BV had built a platform on the local offshore island that now provides a fantastic view of passing humpback whales and we witnessed the first paying customers who sailed out to the island by pirogue on a very windy afternoon!

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[Martyn]

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I see that the blog is finally coming back together. The 404 error I got last week was a shock, I knew it would spell disaster! Fortunately the caches everywhere are coughing up content, slowly but surely.