Trinity Biology Essay Competition

I recently participated in an annual biological essay writing competition that my school holds for my year, having recently read and researched life in the deepest regions of the sea, a topic that I have found fascinating ever since I was a child. The strange alien landscape at the crushing depth of 6000m down, combined with the soft lighting provided by the luminous organisms living there is more than enough to set the imagination of a young mind running. I am glad to report that the essay that I entered on just that subject has won first prize, and I have received a trophy to commemorate this, at least until next year’s winner takes it. I am extremely proud of having come first, and so I am putting up my essay for anybody who wants to read it, as well as archiving it for my own enjoyment. The essay can also be seen in PDF format here, since the formatting is far better than my blog allows me.


Hell on Earth: Life in the Hadal Zone

It was once theorised by naturalists Edward Forbes and Henry Godwin-Austen that no life could exist below the depth of 300 fathoms below the sea surface. Indeed, it seemed that in the crushing pressures and dark waters half a mile down there could be no possible chance of surviving life, and for nearly two decades after Forbes and Austen dredged the Aegean for life in 1841 this Azoic Theory persisted.

Figure 1 A scale diagram of the aquatic layers. Benjamin Stein.

Figure 1 A scale diagram of the aquatic layers. Benjamin Stein.

As more evidence was gathered, we have found that life still flourishes not only at 500m below the surface, in what is now the higher regions of the mesopelagic zone, seen in (Figure 1.), but deeper still, past 1000m in the bathypelagic, and further still, below 4000m in the silent, lightless abyssopelagic zone. It can seem incredible that at these crushing pressures, devoid of light and nutrition life can still exist beyond the form of extremophile bacterium, which use chemical vents to create the building blocks of life. However, deeper still is the hadopelagic zone. Named for Hades, the shadowy land of the Greek underworld, this zone exists only in narrow trenches carved into the sea floor, from 6000m to a staggering 11000m.

In the depths of the hadopelagic zone, pressure reaches over 1000 atmospheres, the temperature is a consistent 4 degrees Centigrade and sunlight has long since vanished. These unfavourable conditions make it a great challenge to reach and research the Hadal Zone, and we still know near nothing about the species here, even though it totals an area equal in size to Australia. Our entire understanding of the Hadal is based on 4 expeditions and surveys, and even they did not provide much conclusive evidence about life in the Hadal. So how do organisms survive at this kind of depth? A habitat of extreme isolation and endemism, the species living in hell have developed incredible adaptations.

Monstrosities in the Deep

The Chimera was a creature of Greek mythology, a gruesome mixture of lion, goat and snake, fused together into a fire breathing monstrosity that struck fear into the hearts of ancient civilization. In the Hades of the deep sea, found at around 5000-7000 metres, is the best known predator of the lightless ocean, the sea devils. Sea Devils are a specific type of anglerfish, from the family Ceratiidae, from the Greek ‘horned’, and are found across the world, in tropical and Antarctic waters alike.

These deep sea hunters are true biological chimera, a single organism made from the cells of different zygotes. This phenomena has been recorded in many species, including humans, where twins have absorbed each other in the uterus and part of the offspring is actually made from a different organism. Where the anglerfish differ is in that they are the only species that purposely seeks to become a mixture of single beings, slowly losing their individuality from their partners and becoming little more than flesh and blood, drifting silently through the Hadal, linked until death.

When specimens of this species were first dredged up from the deep ocean, ecologists and biologist were baffled as to the lack of male individuals found to be captured. Indeed, all of the creatures that they brought to the surface were female, warty brown skin, voracious needle teeth and the famous luminous lure suspended from the front of the face. Even stranger were the tumorous attachments growing from the sides of the females, seemingly serving no purpose. Nearly a century later, in the 1920s, biologists captured a female specimen with two smaller fish attached to her belly by their mouths. A member of the Natural History Museum, Charles Tate Regan, then the Keeper of Zoology, and later the director of the museum dissected these smaller fish and discovered that they were the same species as the female.

Figure 2. Sea Devil. The male bites into the female’s back to begin their fusion.

Figure 2. Sea Devil. The male bites into the female’s back to begin their fusion.

The anglerfish has enormous sexual dimorphism: the males tiny and utterly without the ability to hunt, have found a bizarre way to solve the problems of living in a vast, uninhabited void, where encounters with a member of the opposite sex are rare. Once mature, the tiny male uses an acute sense of smell to locate the nearest female and bites into her belly (Figure 2.) Once there the male releases enzymes that dissolve both of their bodies and fuse their blood streams together. Atrophy of the features ensues, the male loses his eyes, nose, mouth and fins, becoming little more than a parasitic gonad, which the female can use for reproduction as she needs to. The pair will stay like this until they die, the male totally dependent on the female for the rest of what can only be described as its existence.

As the prominent marine biologist of the time, Charles William Beebe, said, ‘to become a brainless, senseless thing that was a fish – this is sheer fiction, beyond all belief unless we have seen some proof of it.’ This is the kind of incredible lengths that species must go to in order to survive in the darkness.

A Light in the Shadows

Like the dreary realm of Hades, the Hadal Zone is a world devoid of colour and sound. It is almost impossible to imagine such a place, unable to hear or see, with only the cold oppressive darkness pushing in from all sides. Communication as we know it becomes impossible, hunting as fish would in shallower waters is no longer viable. To combat this problem, species of the dark abyss have developed their own light – bioluminescence.

From the Mesopelagic zone downwards, nearly all species are capable of producing their own light, through the use of tiny symbiotic bacteria, or by reacting chemicals called luciferins inside their own body. Away from the harsh glare of the sun, the organisms of the deep sea are blissfully protected from ultra-violet radiation and the damage that it inflicts on our bodies on a daily basis. The UVB photons found in sunlight are capable of fusing thymine base pairs within our body, doing damage to our genetic code, and making it impossible to copy. Antioxidants such as luciferins can fix this damage; but without a need for such repairs this new use was found for the spare chemicals.

Almost every problem caused by the pitch black environment that these species live in is solved by their flashing displays. Prey can be lured into striking range, or the target can be illuminated. A confusing flash of luminescence can distract a predator; or a gaudy light-show could draw in larger predators, capable of threatening the original hunter, as is the case with the vibrant Alarm Jellyfish (Fig 3.) It is little surprise that the Hadal Zone is just as rife with glimmering animals as the rest of the ocean.

Viperfish are some of the most common in the upper hadopelagic zone, using their unique photospheres to communicate with potential mates and other hunting viperfish, before seizing smaller prey like lanternfish with their long immobilising maws. While on the hunt, the darkness of their habitat is a great help, turning off their lights and waiting, motionless, like a sinister assassin, for prey to drift past them in the inky blackness.

Jellyfish also make great use of the shimmering chemicals in their body, and their bizarre alien forms can be seen drifting serenely through the depths, leaving mesmerising trails of bright light flowing behind them. Strangely, the red and orange light that many deep sea jellies produce is totally invisible to the eyes of most other sea life, allowing them some limited vision and communication that most of their predators cannot detect. Divers and underwater photographers at lower depths also use red lights, as it allows them to see the animals they are searching for without disturbing or frightening them.

Figure 3 An alarm jelly flashes to attract larger predators. Credit:

Figure 3 An alarm jelly flashes to attract larger predators. Credit:

In a world with no sun or stars, where everything is a blanket of perpetual unnatural night more shadowed than anything we can conceive, light is the ultimate bringer of life in the Hadal Zone. Almost all species there require it to see, hunt and speak. As it is so succinctly put by biologist Edith Widder, ‘In the ocean, bioluminescence is the rule rather than the exception’.

Over the Edge

The Mariana Trench is the deepest marine trench in the world at 11000m – so large that Mount Everest would fit into it comfortably. Challengers Point is at the Mariana’s base, and is the lowest point on earth, the home of the lowest animals, known collectively as benthos. These creatures live a slow life of fierce scavenging for the few scraps of food that can be found, for at such depths supporting a body capable of hunting is nigh on impossible.

Crawling in the muck of the sea floor, these animals rely entirely on the detritus and debris from the pelagic zones above them, pieces of dead flesh and vegetation, often microscopic in size, which drift down and keep these organisms alive. This marine snow comes all the way from the richer waters of the epipelagic zone.

Figure 4. Supergiant amphipod specimen. Credit: © Oceanlab, University of Aberdeen

Figure 4. Supergiant amphipod specimen.
Credit: © Oceanlab, University of Aberdeen

Sifting through the slimy sediment the benthos include the sea cucumber and flatworms, which use tiny mouthpieces to filter through the remains of other organisms’ lunches in order to extract the life giving nutrients. Supergiant amphipods (Figure 4), crustaceans of 10 inches in length dart about the sand looking for larger debris. The sightings of such animals are few and far between, some coming at 100 years apart; with only seven specimens ever caught.

Perhaps the strangest creature that has been found at such depths is a new variety of xenophyophores, peculiar amoebas that live in extremely deep sea areas. Unlike ordinary cells, this single celled organism is up to 10cm in diameter, colossal considering the size of the cells that we use in our body, which have to be viewed with the aid of a lens. Buried deeply in the sand of the sea bed, this extremophile probes out with alien pseudopods to absorb the scraps that drift down.

Lower than light’s touch, lower that the black billowing vents of chemical cascades that provide for tube worms, lower even than the sea bed itself; these animals are the true lowest of all creatures, forced to extraordinary lengths just to find their next meal.

A world of infinite shadow, complexity and challenge, no other creature on the earth must contend with the same conditions as the denizens of Hell itself. Under the pressure of 11000m of ocean and at near freezing temperatures, the most bizarre, ferocious, vivid and tenacious creatures in existence dwell: pressed into evolutionary diamonds by their crushing environment. Daily adversity sharpens these organisms against the dangers of the cold dark abyss with every new generation becoming stronger, quicker and stealthier in the fight to survive. It is certainly true with such creatures that what doesn’t kill you, only makes you stronger. If Hell exists, it is here, 6000 fathoms below the water.

British Biology Olympiad

I recently took part in the British Biology Olympiad, a two hour multiple choice exam for those in the country who are extremely interested in Biology, or fancy themselves a bit of a genius. While I make no claims to being in any way a genius, I do quite like Biology, so I made an attempt in the 2016 event. It was an incredibly difficult paper, and I felt good whenever I understood a question, let alone answered in correctly. There was a wide range of areas, testing all facets of biological knowledge, most of which I have never heard of, and so I am still proud to say I achieved the grade of Highly Commended, slightly below actually doing well in the paper. To those off you who came at the top of the country, and will be heading of to Vietnam for the International Biology Olympiad, I am amazed that you could possibly comprehend all of that knowledge. Good luck, and do Britain proud. I look forward to next years event. With some practise I hope to get a Bronze or Silver award.


Scuba Diving in Plymouth Harbour

Between the 2nd and the 7th of July I went on a trip with my school to go diving in the Plymouth Harbour. I’ve been learning with the sub aqua club for a few months and these were the first open water dives that I would do, out of the pool actually being able to look at the wildlife that inhabits the waters of Britain first hand. These dives were also essential for my BSAC (British Sub-Aqua Club) Ocean Diver qualification, and I had a number of tests, as well as over 2 hours of open water diving to complete in order to become a qualified Ocean Diver and enjoy all the perks that come with that. After 6 wonderful dives and a bit of theory, I am happy to say that I am now an Ocean Diver and have recorded all of my dives in my log. I am now moving on towards my Sports Diver qualification.My red Diiving Log Book, as provided by BSAC.

When you are diving in a new area, it is always important to become used to the layout and to check that your buoyancy is correct for deeper, more advanced dives. In light of this, the first dive of the week was a buoyancy check, adjusting weight belts and jackets so that I could hover in the water without having to wave my arms about, like normal swimmers. When diving without a wetsuit a weight belt is not needed, but since the water was extremely cold I needed to wear one for the dive. Wetsuits hold a certain amount of air in them when you dive, which makes you more buoyant and can lift you to the surface dangerously so the weight belt counteracts this. Additionally, water with a high concentration of salt, such as the ocean, is easier to float in so again more weight must be added to the belt to adjust. Pairing up, we took to the water, a sheltered area of the harbour with a shallow bottom and several small kelp forests. The descent to the water was slippery, especially in our heavy equipment. My mouthpiece tasted unpleasant and salty from the water, and cold ocean trickled down my back into the wetsuit, insulating me from the colder water outside. Sadly I had unbalanced my weight belt and so I spent most of the dive with it trying to pull me onto my back, but I learned the important lesson and next dive my belt was in order.

We went down again, later that day, to a shallow 3.5 metre depth in order to begin the tests I would need to pass to become an ocean diver. We travelled out into the middle of the alien-scape, waving arms of seaweed and darting blurs of fish, and there we sat down at the edge of the larger kelp forest. Here I proved that I was capable of removing my VR (the direct air supply) and finding it again, and that I could take off my mask and replace it underwater, using my nose to clear it of water. I was awarded with a small clap that signals ‘well done’ and we swam amongst the kelp a little more before surfacing. Throughout the first day the visibility had been horrible, pieces of algae and spawn preventing me from seeing for than a metre in front of myself, if that. It had been choppy too, churning about, and sadly this only got worse on the second day, when we were prevented from diving, since it was unsafe. I did some theory instead and prepared for my exam.

On the 5th, to avoid a day without diving, like the last, we moved into Somerset to a filled in quarry called Vobster Bay, which had been made specifically for diving. They had sunk down several speedboats and cars to dive around, as well as the wreck of a Hawker Siddeley plane, whose fuselage I swam through. Small silver fish with red fins and tails swam around me, almost close enough to touch. It was a truly strange experience, like looking out of a fishbowl into a different place almost like I wasn’t really there. I seemed hard to believe I was so close. We went down to 15m for that dive, scooting amongst the wreck.

My write up of the fourth dive on that trip.

Now it was time for me to complete the CBL (Controlled Buoyant Lift), the hardest practical test I would need to complete as an Ocean Diver. My dive partner Richard became purposely limp at 10m down, pretending to be unconscious. I tapped his mask to make sure that he was alright, then grabbed the straps of his dive jacket so that we would not drift apart. Still holding on with one hand, I inflated Richard’s jacket, while venting my own, allowing him to pull both of us steadily upwards. If I had lost my grip on Richard he would have shot to the surface. At 10m down that’s not so dangerous, but from a deeper depth in a real emergency, the DCI from such an ascent could kill a person. One we reached the surface, ignoring the standard BSAC 6m decompression stop, I gave the signal to the ground crew that everything was alright and that it was only a drill, before grabbing the top of Richards tank and towing him to the shore. I did very well and I’m quite proud that I managed to save Richard.My log of the drift dive with Ian.

On the final day of diving, we returned to the Plymouth Harbour to go out on a drift dive. In a drift dive you simply sink to the bottom of the sea bed and allow the current to take you where it wants while you look at the wildlife living in the water. We headed out on the boat to an area called Cawsand Bay and my partner, Ian, and I dropped backwards off the boat into the water. As the current took us about the harbour, Ian and I saw a number of interesting animals, such as tiny anemones that shot back into the safety of the sand when we approached, brittle stars, with their bristly black arms, and even a cuttlefish, one of the strangest things that can be seen in the ocean. These small creatures, pictured below, move by undulating the plates at the side of their body, and can move quickly to capture fast moving shrimps and fish. They have been known to communicate by changing their colour in strange and complex conversations that show their emotions. It was a real treat to see one up close.

An example of a cuttlefish, although it is not the one that I saw.

This is not the cuttlefish I saw, but it is the same species.

In order to complete my Ocean Diver qualification I needed 10 more minutes of diving, to lead a dive, and to pass the exam I had been preparing for. The exam was extremely easy, more common sense and a bit of book reading than actually challenging questions. I passed the exam with flying colours, 29/30. My dive leader attempt was less successful, getting lost and leading Ian through several kelp forests before becoming beached on low tide. Luckily, I had given an excellent briefing and debriefing for the dive and had been attentive to Ian’s wellbeing while under the water, and that was mainly what was being looked for. I’m sure that I will improve as I lead more dives.

Diving is a truly magical experience, the closest that you can get to and alien world while staying on the planet. Unless you intent to become a Marine Astrobiologist, and head off to Europa. I can’t recommend the experience enough, as every moment under the water is the best experience you can possibly have. If you are interested in joining the BSAC group and learning how to dive, visit here. It is only a small fee, and then any BSAC qualified member will teach you whenever you need. As a now proud Ocean Diver, I am looking forward to my next big diving trip, possibly in Malta, and I shall continue to learn with my school club.

Marine Biological Association Membership

I have decided to become a member of the MBA (Marine Biological Association) in order to further my skill and understanding in the career path that I want to pursue. Based in Plymouth, they provide opportunities and support for marine biologists and ecologists across the UK, funding research programs and providing laboratories to biologists in need.

As a member I now receive an interesting and informative magazine every so often, keeping me up to date on what is going on in the community. They also provide a number of opportunities and lessons to budding marine biologists, such as their work experience program that I intend to apply for. If you have an interest in marine biology, or simply want to read more about them, you can find their website here. If you are considering becoming a marine ecologist or any related job in the UK, I urge you to become a member as soon as possible.