Rapid evolution: Swept under the proverbial oceanic carpet...

It is clear that human activities are effecting the environment at an unprecedented rate.
Fishing is a major source of food and other resources for humankind. Today most marine fish stocks are heavily exploited, and many are overexploited. Such intensive utilization has raised concerns about the sustainability of the modern fishing industry. But the problem lies deeper than this, as fish stocks crash, it is likely that other environmental variables are experiencing the secondary effects of such large scale disturbances. In recent times it has become clear that such actions by humans may be responsible for the rapid evolution of a species.

An understandably tentative theory involving the genetic changes of exploited fish stocks in a diverse and variable environment. Over the last few decades scientists have been observing phenotypic changes in fish populations, producing theories as to why such changes may be occurring.

Due to the high levels of mortality, size and selective nature of commercial fisheries, it is likely that particular life history traits will be selected for in exploited fish populations. Differentials have been found to be high for characteristics such as body size and age of maturation. Historically, larger fish are more valuable and more sort after, a late maturation means species spend more time in areas that are at risk from fishing practices, being caught before they even spawn. With such risk, there has been a reversal of fitness. With those that a smaller less easily caught and spawn early becoming more fit within the population. For example, heavy harvesting of Pacific salmon of a population returning to spawning streams; severely alters selection on life history traits. By differentially removing larger fish from harvested populations, fishing exerts intense selection on age and size at sexual maturity, this response to harvesting practices has been reported for many fish stocks.

Using the BFF (Big Female Fish) rule, when maturation takes place earlier and average size of fish is decreases, sustainable yield of large fish, producing many more offspring decreases and so does the market value of catches. If the observed changes in maturation have a genetic component, unless harvesting methods are radically changed it is unlikely that stocks will recover and more importantly it is unlikely that species will never recover to their former large sizes and late maturations. Genetic recovery occurs much more slowly than ecological recovery. It is therefore in the interest of fisheries managers to prevent unwanted genetic changes as early as possible.

It is important to acknowledge that there is till much conflict surrounding the role of fisheries induced evolution, however, most scientists agree that it does occur in some form yet to what extent in debateable. For example present day cod mature at a much younger and smaller size than their ancestors at the begining of the 20th century would have done when faced with similar growing conditions. Suggesting genetic changes rather than a plastic response to environmental variation.

Not only is the suggestion that the over exploitation of the oceans is causing a rapid evolution of many species alarming, but these effects may cascade to other species causing impacts on biodiversity and ecosystem functioning. Or quite simply, the monsters our Great Great Great Grandfathers caught off Britains coast line will be a thing of the past and remain there indefinately.

The Plight of the Coral Reefs

The forests of the sea.

Although only making up 0.1% of the worlds oceans, they are home to over 25% of all marine species. Coral reefs are some of the most diverse places on earth, yet relatively little is know about the complex interactions between the thousands of species that call them home.

Only a few get the opportunity to experience the wonder and the beauty of this Xanadu, but of places on earth that deserve conserving the reefs come top of the list.

Climate change and its influence of marine and estuarine species is still relatively unknown yet it is apparent that large scale changes are likely to occur.

This is likely to impact upon not only commercial valuable or ecologically important fish species but also the structural and non-structural invertebrates and plants that play an important role in ecosystem functioning. Research and evidence of how species have changed in their distribution, abundance and composition as a result of increasing sea temperature is growing.

Scientists however, face a predicament. The effect of non-climatic variables and how these can be disentangle from direct human exploitation and the expected impacts of climate change.

For the moment coral reefs have an uncertain future. Scientists believe that without intervention, after 50 years these diverse marine habitats pulsing with life and colour will give way to banks of eroding limestone covered in suffocating algae.

To date only 0.5% of the earths oceans are protected, a shocking statistic that requires desperate action. Marine protected areas are, in some cases, the only option. Parts of the ocean are still yet to be explored, however such unique habitats and species could be lost even before the are discoverd. An ocean without reefs would set the scene for the dire changes the world is experiencing, a world that is worth nothing if these 'forests of life' are lost forever.

Somewhere,

something incredible

is waiting to be known.

- Carl Sagan

Underwater Love

Today was the day I explored the underwater world. It had been pouring with monsoon rains as I woke the morning before my dive. I had been reassured by my instructer that it didn’t matter as you would already be wet! My thoughts went to how different and undetectable rain must be under water.

After learning the basics I felt confident about diving, however, things are very different when your dumped in the middle of the ocean. The sun was bright when we took the boat to the dive site, the water was rough, the boat was at the whim of the waves bobbing from side to side, with a nauseating feeling encroaching on my excitement I was desperate to get into the water. Once my diving gear was secured I took a ‘giants step’ into the water following my instructor. I was slightly apprehensive to be having this experience for the first time alone. But the best experiences are personal and when you are in a world made of water you are alone with your thoughts any way.

As we were about to descend my nerves got the better of me, I was surrounded by an expanse of blue, deep and endless, with no idea of what lay below. Finally I controlled my breathing, all that I could hear was the rhythmic bubble making and of my regulator and a slight crackling noise surrounding me. In front of me was murky blue, I didn’t know how deep we were then as I turned to look below, a whole new world was opened. Life was swarming; rock shelf gave way to an expanse of corals in every colour. The first fish we came across were small and electric blue, feeding on the rock. As we swam forward so much more colour appeared, fish of purples, greens and blues surrounded us. I recognised many fish I had seen before in aquariums and it made me feel at awe that I was seeing these creatures in their wild and natural habitat.

As we ventured deeper, schools of fish weaved their way in and out of rock crevices. As I looked ahead a black and white zebra fish came right up to my mask. It looked so inquisitive and un alarmed by my presence. It made me think, we don’t know just how intelligent fish are and just referring to them as seafood is not giving them enough credit!

There was so much diversity in the world I was observing, I tried to capture every moment in my head so I could refer to it later, an imprint, an ingrained memory. But there was just so much to see, and as soon as I saw it I felt the image already beginning to fade. The colours were unimaginable, such intense blues and yellows, it was hard to think that such colours were a product of nature and not an artist. I struggled to think of places on land which would be home to such diversity of life, such different organisms inhabiting one small slice of the earth.

Then the dive was over, I knew we must have been down there a while but it seemed like we had only just begun. As we ascended, shafts of light began to break through the surface, painting all the microscopic creatures which began to shimmer, the water was full of golden filaments. It was good to breathe the air once more but strangely foreign after breathing under water.

The boat was still swaying, a monotonous and nauseating movement but we were soon on our way back with fresh ocean spray in our faces. As we returned I began to think about what I had just witnessed a great richness of life that comparatively few people are fortunate to see. To my surprise I felt saddened after the experience, my thoughts were on just how much harm we are doing to the oceans and how much we have already harmed the land. In my life time I had witnessed such great diversity but wondered how long this would last with the rate of human destruction. For too few the oceans don’t seem to be an important part of their lives but our oceans and seas affect us all, they should be our priority. As I looked out at the un interrupted waters I had a renewed understanding as I now knew just what lay beneath, I had fallen in love with the ocean all over again.

When It Rains It Pours

It is hard to describe the rains in Silhouette, to do them justice would be to see them. You hear them before they fall, as the clouds role over the highest point (Mt. Dauban 720m) the rain falls in sheets of cool. Distant at first, with a sound like roaring wind and rustling leaves, they move down the mountain side. The volume increasing as the rain reverberates off the giant palms down through the forest. Eventually when the sound and force reaches its peak, quiet descends. As soon as it had come it had gone. Now once warm ocean breezes are cooled and hot dry air now quenched. With the rain comes all the smells of the forest. The damp earth and smells coloured with green, the atmosphere now thick with moisture coats your lungs as you breathe more deeply. As the clouds fade to sun, normality resumes, earth dries in seconds and north westerly winds sweep the forest smells away and all that remains is the last drops of moisture that still cling to the air, a memory on the wind.

Journey to the summit

The Jungle awaited. Since I can remember I have craved the Jungle. There is something alluring about the prehistoric trees reaching ever upwards into a closing canopy. Something that has been seen by so few human eyes, untouched and untarnished. The Jungle is an amazing natural experiment; here you can really see what nature can do, when left to its own devices.

I have been up the mountain on Silhouette a few times now and in all cases, the paths are steep and unforgiving. The climb begins

with a gentle slope which quickly converts to steps of the jungle. Gnarled tree roots lay exposed, manipulating the soil and rock above and below them. They provide a natural stair case up the mountain, interceded with volcanic boulders and wind etched rock. Leaf litter deepens as you gain height and with it comes the smells of a forest at work. All year round leaves fall, flowers bloom and fruits drop, the smells

are sweet and musty. The air is heady with the smell of decomposition, as wood and leaf becomes part of the root mat under foot. It’s not an unpleasant smell, It smells almost ancient or prehistoric. Wet and earthy accented with the occasional sweet and sickly jack fruit. As your rise further into the forest the air is thick with the smell of aniseed and cinnamon, products of plantations on the island.

The terrain is difficult and often you find yourself using trees as levers and vines to swing. Some parts of the forest are glacis which are large boulder fields. Here volcanic rock

has fallen and formed bridges over valleys, made up of huge boulders up to 5 meters in diameter. Occasionally these have to be crossed.... the surface of these are completely smooth, blue green algae, moss and lichen have taken over but through time wind has polished their surface. In some places you have to hall yourself onto the rock and cling on whilst simultaneously sliding to level ground. When it’s wet, it is particularly dangerous as walking boots offer no grip when presented with blue green algae.

On my way to Mon Plasir (the highest point I would reach) We came to Jardin Marron – the garden of the wild. This was a s

mall stretch of level ground half way up the mountain. Here It is said that during colonisation of the island some slaves escaped and made their home here. Some of the forest has been cleared and papaya, Jack fruit and coco de mer trees remain. They do not produce a seed so must have been planted there by someone...

Very few people take the track up to Mon Plasir so the path is rough. The incline is often vertical

so it is a case of grabbing hold of something and pulling yourself up. The forest begins to change at this point as moss covers every surface, the clouds lie at this level so visibility decreases and humidity increases 10 fold. Once at the top the temperature has dropped by 3 degrees and the north westerly winds can be felt rising up over the ridge. I was lucky enough to be able to go to the ancient pazonia forest a little way down the other side of the ridge. Here the vegetation has really taken over with wild raspberry bushes, tree ferns and endemic spiky palms abundant.

After fighting our way through the vegetation with machete in hand we came to a clearing, it was beautiful. These prehistoric trees stretched far upwards flatting out in weird triangular shapes at the top. Vines hung down from the trees as well as winding they’re way up the trunks. It was something right out of a George Orwell novel. Above us fruit bats screeched over head and tropical birds nested.

They weren’t fancy but they flew with great elegance, white and streamline with delicate whisping feathered tails of half a meter long.

After taking some samples we started the trek back. I realised the jungle looks the same from every angle but my supervisor seemed to remember the path so I followed behind- with a bit of distance as he was brandishing his machete wildly.... You may think the decent is the easy bit, but it’s actually quite tricky as you begin to look down to the forest below. After a while I got the hang of it, swinging from trees for balance and being careful not to grab the native palms that have evil spikes. I took the advantage of having vines to swing from and for reassurance. After a while I began to really enjoy this obstacle course winding up and over fallen trees and down landslides, tip toeing over slippery boulders. The pace was fast now as my supervisor charged ahead, it was important not to lose concentration as sometimes after tripping on a vine it seemed like nature was out to get you. Or perhaps, just giving you a friendly tap on the shoulder to let you know she was still there....

However, that’s just what my supervisor did. He got his foot caught in a tree root and had tripped twisting his knee and slicing his hand on his machete. Glad I stayed well back.... Luckily I had brought tissues and plasters but the journey down was going to be made more difficult. It seemed to last forever, with the quiet of the Jungle it is easy to get lost in your thoughts and often I found myself repeating them over and over again and was only awoken with the occasional grunt of my supervisor in front.

We came across many landmarks of carved rock and fallen tree that seemed so familiar, I knew we were nearing the bottom. As I landed on level ground my legs felt like jelly, I was scratched to buggery, sopping wet, so tired but happy. It was the most gruelling walk i have ever done but well worth it.

Arrival in paradise

By heck it took long enough!.... Actually, the time went surprisingly quickly, although, 2 hours from my destinations we hit turbulence that, I have to admit, scared me half to death. It felt like we were falling out of the air! Of course It was not helped much by the continuous shouting of an American man net to me "O fuck, O fuck, put your seat belts on. I felt my self subconsciously reaching for the pedals....

As the air craft came into land the on board cameras showed the characteristic islands with turquoise waters. As soon as I got off the plane the humidity hit me, a sweetly scented wave of what can only be described as "stuffyness". Once through immigration (this took a while) the next task was to get a taxi. This was a difficult job. One always strives to acquire a taxi man that looks the least shifty, unfortunately I had slim pickings - so instead, I choose the safest looking car....

Once at the Island development company, after a few strained conversations with some men outside- in which they asked questions in English and proceeded to answer them in Creole.... Eventually I got to see the infamous "Stella", who I had been in correspondence with. I can honestly say she was one of the loveliest people I've met, in fact everyone seems really nice.

I was still yearning for paradise, as of yet I still had not come face to face with the idyllic white sandy beaches and warm ocean that the Seychelles is famed for. Instead I wound around the built up areas, with roads and shops for the need of every tourist. However, there was no mistaking this was a tropical island. The mountains rose up above the built up suburbs, covered with untouched tropical jungle.

The air smelt different too.. When I stopped in Dubai it smelt like old carpets, but here, here it was sweet with tropical scents and ocean winds.

Stella showed me around the town, which as it transpired, was actually an excuse for a shopping trip in which she was looking for a wedding outfit. My God they like things sparkly in the Seychelles.....

At last I left Mahe on the speed boat, I was so tired but the occasional spray of salty sea water woke me up. The Island was a perfect little paradise in the middle of the ocean. It gets dark at 6.30 here so I didn't have a chance to explore, that would have to wait till tomorrow....