By David Sims, Professor of Marine Ecology, University of Southampton

Steven Spielberg’s Jaws opened across North America on June 20 1975, and immediately tapped into the primal human fear of being hunted by a huge, savvy predator.

Set on a fictional island off the coast of New England, the film depicts an epic battle between three men on a boat and an enormous great white shark. Jaws was hugely popular, grossing a record US$100 million in its first 59 days.

Young and already mad about sharks, I left the film wanting to know more about their behaviour and ecology. But films affect people in different ways, and the movie has since spawned what social scientists call “the Jaws effect”.

This contended that sharks became widely demonised as a result of the film’s depiction of them as relentless killers obsessed with attacking humans. Director Spielberg’s inspired use of fleeting glimpses of the shark’s fin knifing through the water, accompanied by the film’s sinister and unforgettable music, heightened those feelings. That’s how Jaws affected us. But 50 years on, how have shark populations fared?

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Both Spielberg and Peter Benchley, Jaws author and screenplay contributor, regretted the film’s influence on public perception of sharks. Indeed, Benchley became an advocate for shark conservation who enjoyed working with scientists (I was invited onto his radio show to discuss my research satellite-tracking basking sharks).

In the years following the film’s release, increasing numbers of sharks – including the movie’s great white – were reportedly killed in shark fishing tournaments that had risen in popularity.

Sharks grow slowly, take a long time to reach sexual maturity and have relatively few offspring. This makes many species vulnerable to overfishing. Fishing at this level removes too many sharks from the population too quickly, such that the remaining sharks cannot replace them fast enough, and the population declines. A recorded decline can be relatively large if the starting population size is already small, like that of top predators such as the great white shark.

Several data sources, including rod-and-reel and longline fishing, indicate a significant decline in the abundance of white sharks in the 1970s and 1980s along the US east coast where the film is set. The Jaws effect in action?

Actually, rapid declines were not limited to US waters. White shark catches in bather protection nets off the southeast coast of Australia recorded a similarly large decrease in the mid-1970s. And this particular source suggests white shark populations had begun declining from the mid-1950s, 20 years before Jaws.

Additional factors, such as commercial overfishing, were obviously at play. The film’s influence probably exacerbated white shark declines that were already happening.

Globally, the white shark has been assessed as vulnerable by conservationists, with a decreasing population trend. Fortunately, there are signs of recovery.

National protection measures for white sharks were implemented in the 1990s where these animals were formerly abundant, like the US, South Africa and Australia, and worldwide protections came a few years later.

Since the 1990s there have been apparent increases in abundance off the US east coast (when populations are so small and data so sparse, a short-term increase may not be a lasting trend). Welcome signs that measures, such as prohibiting catches in 1997, are having a positive effect following decades of over-exploitation. But this species is still vulnerable to incidental capture, so protection measures must be maintained and enforced to sustain any recoveries.

The Jaws effect was not limited to great white sharks. Many other large sharks were captured and killed in shark fishing tournaments that became more common following the film. Unfortunately, the killing continues in remaining US tournaments today.

But over the past few decades the overwhelming cause of large shark declines globally, particularly in the open ocean far from shore, has been the expansion of industrial-scale commercial fisheries targeting sharks for their fins and meat.

It was estimated in 2024 that fishing vessels are killing around 100 million sharks a year – a number that rose during the last decade. Nearly a third of shark species are now threatened with extinction.

It was estimated in 2021 that the global abundance of shark and ray species which prowl the open ocean (such as the oceanic whitetip or shortfin mako) has declined by an average of 71% since 1970 due to rocketing fishing pressure on the high seas (areas beyond national jurisdictions).

My own research analysing shark satellite tracks in collaboration with over 150 shark scientists showed that 24% of the space used by these sharks each month on average falls under the footprint of surface longline fisheries. These include vessels that can deploy lines 100km-long carrying 1,000 baited hooks for up to 24 hours. We found the overlap was even greater, about 75%, for commercially valuable species such as the blue shark.

More sharks die in these overlap hotspots than in adjacent areas, according to more recent research.

Demystifying Jaws

Are there any signs of recovery for these species under existing management measures? For many oceanic sharks, the answer is still no.

At present, measures in place (if any) on the high seas are insufficient to safeguard populations. There is very little or no protection of shark activity hotspots. And some of the measures, such as shark finning bans, have been shown to be ineffective.

My colleagues and I revealed that catches of internationally protected species are sometimes 90 times greater than official reports.

So there is still a very long way to go to rebuild global shark populations.

Jaws helped promote a negative image of sharks that has no basis in reality. Rather, shark behaviour appears as complex in some cases as that of birds and mammals.

Tracking sharks revealed they can migrate thousands of kilometres to feed in specific remote habitats, before returning to the very same place they left months before. Some prefer to hang out with familiar individuals, and sharks even form persistent social networks. Giant basking sharks take part in speed-dating-like behaviour when they form courtship swimming circles at the end of summer.

The serial killer image has probably made it harder to convince people to sympathise with the plight of sharks. Jaws came at a time when very little was known about sharks, so fiction filled the void.

But there are now more shark scientists thanks to Jaws. Demystifying these creatures has been the first step to their potential recovery.

David Sims is Professor of Marine Ecology at the University of Southampton. This article is republished from The Conversation under a Creative Commons licence. Read the original article.

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Todd Thimios has what many would believe to be the perfect job – he travels the world on private yachts, searching out the very best dive sites for his clients. His 20 years of luxury wandering has resulted in Ultimate Dive Sites – a glossy book listing his 50 favourites dotted around the globe. Here are three to whet your appetite…

Words and photographs by Todd Thimios

MILFORD SOUND, NEW ZEALAND

Dive below mountains and waterfalls into an environment you’d usually find 200 metres deeper

The South Island of New Zealand – Aotearoa, in the native Māori language – is world-renowned for its dramatic mountainous scenery, and there are few places more dramatic than the Milford Sound. For divers, black coral is the main attraction, but the Sound has much more to offer, and the magic begins with the drive in.

According to Māori legend, Aotearoa’s fjord lands were carved out by the demi-god Tu-te-raki-whanoa, who, upon reaching
Piopiotahi (Milford Sound), did his best work before ending his journey. Undoubtedly, this is one of the prettiest landscapes on Earth, but if you think Milford Sound is otherworldly, wait until you see what’s below the surface.

While technical diving and the discomfort of wearing a drysuit deters many divers, the fun of exploring the ethereal world beneath the fjords is absolutely worth the effort.

Known as New Zealand’s ‘coral capital’, some of the interesting coral trees that you’ll find here are those of red and black corals. Despite their name, black corals are actually white in appearance, thanks to millions of miniscule white polyps in a thin layer of tissue covering the coral’s black skeleton.

Finding these usually deep-water corals in shallow water is a novelty, made possible by the murky surface layer of freshwater run-off blocking out the sunlight. The existence of deep water animals surviving at shallower depths is called ‘deep water emergence’.

With nearly 6,800mm (267in) of annual rainfall, this is one of the wettest places on Earth. As the rain falls onto the mountains, it pulls nutrients from the forest floor down into the sea, creating a blanket effect on the water’s surface.

The result of this murky, tannin-stained water is an incredible marine environment that is starved of light – an ecosystem typical of 200m (656ft) depth is found within only a depth of 10–20m of water.

There’s an eerie feeling for the first few metres as you descend into the murkiness, but once you’ve reached the bottom of that freshwater blanket, the visibility and scenery opens up to dramatic walls hosting large branches of snow-white coral, stingrays, octopuses, nudibranchs, dog or carpet sharks, and clusters of crayfish, all enjoying the protection of the 690 hectare (1705 acre) Piopiotahi/ Milford Sound marine reserve.

If you’re lucky you may spot a New Zealand fur seal or some bottlenose dolphins. A day with local operator Descend Diving (currently taking a break from diving) will have you zipping through the Sound and out to the Tasman Sea, with scenic stops for waterfalls and wildlife spotting.

Two dives are offered and those without prior drysuit experience can pay extra to get training and a certification while on the tour.

With the dive boat setting off from the boat ramp at 9 am, I recommend that you stay close by, rather than driving the winding road (which is prone to rockfalls) in the dark.

There are chalets and a campground at Milford Sound Lodge (milfordlodge.com), but they book out far in advance. If you can’t stay there, the next option is the town of Te Anau, 118 km (73 miles) away; allow about an hour and a half for the drive as the 1.2 km Homer Tunnel can get congested sometimes.

If you’re driving a campervan, there are also some great, cheap Department of Conservation (DOC) campsites, which are positioned in scenic locations along the drive in (doc.govt.nz).

Best time to dive: October-April.

Gear: it’s cold and dark, so drysuit, gloves, hood, socks, thick undergarments and a good light.

Photography tip: Showcasing the landscape both above and below the surface was my main focus, so I felt that shooting wide was the best option. I used an 11-24mm zoo,m which yielded good results of both marine life and divers among Milford’s cold-water reefs. Ensure your strobes are reliable, as even though visibility can be good, it gets dark real fast.

SS COOLIDGE, ESPIRITU SANTO, VANUATU

Dive deep into an underwater museum of WWII relics mixed with 1940s opulence

Whether you’re a relative newbie to deep water diving or a seasoned deep-sea technical diving adventurer, the SS President Coolidge on Vanuatu’s stunning Espiritu Santo Island offers a fantastic wreck diving experience.

The SS Coolidge isn’t just any shipwreck, at 198m (650ft) long and roughly 22,000 tons (24,000 tonnes), it’s arguably one of the best wreck dives in the world, and you can walk straight off the beach to access it.

Once a luxury passenger liner with elegant cabins and plush restaurants and bars for more than 1,000 people, it was transformed into a troop carrier during World War II when 40,000 troops were stationed on the rapidly converted Espiritu Santo, making it the second largest American base in the Pacific.

It was here in 1942, while entering Santo’s harbour, that Coolidge collided with its own US mines. The ship’s sailing orders had omitted vital information about safe entry into the harbour, and with fears of Japanese submarines looming large, the captain attempted to navigate through the most obvious of channels.

A mine struck her in the engine room, followed by another near her stern. Over the next 90 minutes, 5,340 men from the ship got safely ashore, with only two lives lost. However, the captain’s attempts to beach and save the ship were shortlived.

Coolidge listed heavily on her port side, sank stern first, and slid down the slope into the channel. Today her stern sits in 72m of water and her bow in 20m, creating a sanctuary for deep wreck diving and one of the most unbelievable shore dives imaginable.

Gearing up on the beach, divers take a short walk to the tide line, and after swimming only 40-odd metres, the bow comes into view, marking the beginning of the colossal structure that is the wreck of the Coolidge.

Diving Coolidge is like entering a time capsule. Back in 1980, when Vanuatu gained independence from its French and British colonisers, it was declared that no artefacts would be allowed to be salvaged from the wreck. So today, with the ship still largely intact, divers can swim through its holds and decks, encountering an array of relics from guns, cannons and Jeeps, to helmets and personal supplies left behind by the troops.

Then there’s relics like ‘The Lady’ (a porcelain bas-relief and divers’ favourite), chandeliers, a mosaic tile fountain, elegant baths and grand staircases, which all add to the charm.

While Coolidge is a labyrinth of corridors, rooms and cargo holds, this shouldn’t deter new divers. To truly appreciate the ship’s magnitude and majesty, I recommend at least 10 to 15 dives. After all, she stretches almost 200m in length. But even with just a few dives you can get a taste of her grandeur.

For me, a return to Santo 20 years after I lived here allowed me to see how the wreck has fared over the years (particularly since Vanuatu gets its fair share of cyclones and earthquakes). While a few structures have collapsed (the promenade deck, mainly, and the swimming pool which popped out and fell to the ocean’s floor), overall, the wreck hadn’t changed much. It’s still solid and safe to explore, with the right guides.

Diving in Luganville was pioneered by the legendary Allan Power back in the ’80s. Allan operated a dive centre here right up to his death in 2018. He had made over 15,000 dives on the Coolidge and had taken more than 20,000 divers to the Lady alone.

His legacy is carried forward by Pacific Dive, situated within Luganville’s Espiritu Hotel, which runs daily dives. Its local Ni-Van staff take great pride in the Coolidge. They are incredible guides, accruing tens of thousands of dives between them on the wreck over the years (pacificdive.net).

Best time to dive: year-round, but the May-October dry season is best for sea conditions, temperature and visibility.

Gear: 3mm wetsuit over summer and 5 mm over the colder winter months.

Photography tip: Pack your favourite wide-angle lens and dive Coolidge several times to capture the bow and the full length of the ship when shooting her from outside. Inside, strobes are turned on to focus on the many different chambers and artefacts within.

MERGUI ARCHIPELAGO, MYANMAR

For decades sea gypsies have had this region all to themselves… until now

Off limits since World War II, the Mergui (pronounced mer-gwee) Archipelago in southern Myanmar (formerly Burma) opened to liveaboard dive boats in 1997 and, since then, word-of-mouth about the region has started to spread through the diving world.

Their relative isolation and history of being closed to tourists due to Burma’s military regime have helped them maintain their pristine and undeveloped state.

Known to the outside world by their British colonial name of Mergui (the indigenous name is Myeik), these 800-plus islands are scattered across 400km (248 miles) of the Andaman Sea, down the coastline of Myanmar.

Devoid of hotels and beach front bars, the jungle-clad islands, some of them still unnamed, are inhabited only by a few thousand Moken ‘sea gypsies’, the indigenous people of the Mergui Archipelago.

These semi-nomadic people have traditionally spent their days fishing or boat-building and are known for their incredible freediving abilities. For the Moken, the only tourists that they see are a small number of divers or adventure cruise ship passengers, passing through.

On our expedition, we set sail from Kawthaung (Myanmar’s southern gateway to the archipelago), though commercial liveaboards also depart from Ranong across the Thai border. Most of our trip was based around several well-known sites, with the rest of our trip visiting unknown sites for exploratory dives.

Our captain’s favourite dive was Black Rock, one of the Mergui’s most westerly islands. Standing solitary in the sea with a steep wall dropping down to over 100m (328ft), this pinnacle is a magnet for marine life, giant mantas, vast schools of barracuda, trevally, snapper and fusiliers clouding the waters.

Underwater, this limestone rock is covered in soft corals and anemones; the reef’s crannies and crevasses a haven for scorpionfish and other benthic critters.

At night, the dive site transforms as colourful corals bloom and nocturnal creatures emerge to feed in the nutrient-rich waters.

Another favourite spot was Western Rocky. The island is known for its sharks, including whitetips and blacktips, grey reef sharks and some large nurse sharks, which can be spotted inside a tunnel dive that cuts through the island’s core.

Just north of Western Rocky, a dive site aptly named Shark Cave is also good for spotting nurse sharks, plus whip rays, blotched stingrays and the odd whale shark, and then there are smaller cuties such as seahorses and anemonefish.

Perhaps the highlight of the trip, for me, was the huge gorgonian sea fans found in numerous locations, with a dive site named Fan Forest Pinnacle (also known as Rocky Peaks) being especially populous with wonderful gorgonians. To this day, I would say that the largest and most impressive gorgonian fans I’ve ever seen were in the Mergui Archipelago.

While the Mergui Archipelago has many amazing dive sites to explore, the visibility can be a bit all over the place. Cold-water currents bringing nutrients (commonly called ‘the green monster’) can rush through dive sites unexpectedly.

Some areas have been fished hard, while others have been decimated by dynamite fishing. Then, on some dive sites, ghost nets litter the reefs.

While the archipelago is just beginning to find its feet as a world-class destination for divers, it’s crucial that the government protects the region, not just for the future enjoyment of divers, but also for the Moken people who call it home and depend on these waters for their food, lifestyle and income.

The MV Smiling Seahorse has been running liveaboard dive trips to Mergui since 2012 and offers several scientific and exploratory itineraries. Trips on this small boat, which takes only 16 divers, depart from Ranong in Thailand (thesmilingseahorse.com).

Best time to dive: late October to mid-May for calm seas, blue skies, better visibility and a steady water temperature of 27°C (80°F), which aligns with the migratory patterns of large pelagics, including mantas and whale sharks (Feb–May is prime season for the big stuff).

Gear: 3mm wetsuit for water temperatures around 27°C (80°F) from late Oct to mid-May.

Photography tip: Mergui has a bit of everything: megafauna that needs a wide-angle lens, coral garden seascapes that suit a wide-angle zoom and incredible critters for your macro lens. If possible, pack it all, particularly your wide-angle.

More great reads from our magazine

• Painting with light – an interview with Catherine Holmes
• Artificial Intelligence – good or bad for underwater photography?
• Liveaboard safety – how divers can change it and when to walk away
• Luxury resort versus budget homestay in Raja Ampat
• DIVE’s Big Shot Portraits – THE WINNERS!

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The Sheba brand, part of the Mars family and more familiar as a brand of cat food, has announced a new documentary, Reef Builders, now streaming on Amazon Prime Video.

The new documentary, announced in March this year, was premiered at a ‘teal-carpet’ event hosted by Sheba at The Natural History Museum in London on 10 April.

Reef Builders spotlights the story of the Sheba Hope Grows initiative, one of the world’s largest coral reef restoration projects, first launched by the brand in 2021 as a Mars Sustainable Solutions (MSS) programme.

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The documentary, directed and produced by Stephen Shearman and featuring Hawai’ian actor and environmental advocate Auli’i Cravalho (voice of Disney’s Moana), opens with an overview of the project’s largest success story to date, the restoration of HOPE Reef in Sulawesi, Indonesia.

The Hope Reef story is told through the lens of a local Bontosuan fisherman named Samaila, who has witnessed the massive loss of coral from the reef and its subsequent regeneration through a construction formed from a simple, but ‘revolutionary’ steel structure referred to as the ‘Reef Star’.

Reef Builders also visits Lamu in Kenya, Australia’s Moore Reef, and Auli’i’s native O’ahu, Hawai’i, to explore how the MSS team, led by Chief Marine Scientist Professor David Smith, partners with coastal communities and NGOs to expand the network of coral restoration programmes.

‘I’ve witnessed decades of coral reef devastation due to rapidly warming oceans, over-fishing and over-tourism,’ said Prof Smith. ‘Restoring the world’s coral reefs isn’t something that can be undertaken alone – it requires the ocean community, businesses and consumers from all corners of the earth to unite around the reef builders and scale their efforts.

‘While we’ve seen promising success since the inception of the program, we still have a long way to go on this journey. Gaining the support of all who view this documentary will help us further the program immeasurably.’

According to the  MSS Impact Report, 2024, the MSS team and its partners have installed more than 87,000 Reef Stars, which have approximately 1.3 million corals attached to them. As well as providing an insight into the coral restoration programme, the Reef Builders documentary will help raise funds for the initiative.

Between 13 April and 29 June, Amazon will donate US$1 for every hour streamed in the US – up to a maximum of $100,000 – to the Kuleana Coral Restoration foundation in Hawai’i, and CA$1 for every hour streamed in Canada – up to a maximum of $30,000 – to the Corales de Paz reef protection project in Colombia.

‘Growing up in the islands of Hawaiʻi taught me just how lucky we are to live in harmony with our oceans,’ said Auli’i Cravalho, actor, environmental advocate and Reef Builders associate producer.

‘It’s easy for me to want to protect my own backyard, but this film allows audiences around the world to come together to learn about the vital importance of coral reef restoration.

‘The huge platform that Prime Video provides will allow those both near and far from the restoration conversation to have a front row seat not only to coral reef degradation and restoration, but also the profound impact on local coastal communities.’

To learn more about the documentary and the Sheba Hope Grows programme, head to SHEBA.com/Sustainability 

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A review of Treasures, Shipwrecks and the Dawn of Red Sea Diving, by Howard Rosenstein, published by Dived Up – now available in paperback

Review by Mark 'Crowley' Russell

Most people who have visited Sharm El Sheikh will be aware of its history, and many will have seen photographs on dive centre walls of the days when it was first discovered by dive tourists; early pioneers piling scuba tanks on camels and ferrying divers through the desert in army surplus jeeps – with not a hotel in sight.

There wasn’t even a proper building when Howard Rosenstein started his first scuba diving shop in Na’ama Bay – it was an old railway freight car dumped on the beach next to the Marina Sharm Motel, which was, at the time, a collection of hemispherical fibreglass ‘rooms’ arranged in a vaguely organised manner.

I first discovered Sharm as a holiday diver in 2000, when the hotels of Na’ama Bay still occupied just one side of the road, and watched the resort grow dramatically over the next four years.

I would return in 2009 to spend the best four years of my career as a dive professional in the love of my diving life – and I like to think that I caught the tail-end of that golden era.

What I wouldn’t give, however, to see the Sharm El Sheikh of the 1970s, having gazed so longingly at the photographs on my dive centre’s walls. So it was with great relish that I sat down to read through Rosenstein’s Treasures, Shipwrecks And The Dawn Of Red Sea Diving: A Pioneer’s Journey.

In just a matter of hours, I was turning the final pages.

There is something extremely endearing about the tales of the early years of Red Sea diving; a time when it seemed scuba training involved little more than a promise not to hold your breath or run out of air, and you could – as Rosenstein did – walk into the water, find sunken treasure, and sell it days later in back-street markets in a manner reminiscent of scenes from an Indiana Jones movie, but damper.

It wasn’t all innocence, as political tensions in the region were high, peaking with the violence of the 1973 Yom Kippur War, as Egypt attempted to regain control of the Sinai Peninsula from Israel.

Rosenstein found himself not just a pioneer of scuba diving but negotiating his way through the turbulent political climate, even working to help broker a peace deal between the two nations, even if it might mean that he, himself, would have to leave.

Treasures, Shipwrecks And The Dawn Of Red Sea Diving is excellently written, and captures well the author’s decision to emigrate to Israel from America at the age of 23, where he opened his first dive shop; his subsequent move to Sinai and the founding of the scuba travel business that would eventually form a significant percentage of Egypt’s GDP.

His style of writing is rather snappy – in a good way, like a fast-paced airport thriller – and often reads like a series of joined-up, well-told, deco-beer anecdotes, but with a lot more depth, a lot less beer, and many more interesting characters than the average post-dive stories.

He hobnobbed with luminaries such as Hans and Lotte Hass, Anne and David Doubilet and Eugenie ‘Shark Lady’ Clark – with whom he would become firm friends, and with a variety of famous celebrities and important political figures in a tumultuous era of modern Middle Eastern history.

Complementing the writing is a continuous stream of photographs documenting exactly what those early years were like, from candid amateur snaps never before seen in public, to some of the Doubilet’s finest.

If I were to have a criticism of the book, it is that there is not enough of it! It’s just over 200 pages long but I really could have gone another couple of hundred in the same sitting.

I would also like to have read a little more about the early years of the dive business in Sharm, although this is not so much a criticism of the book as wishful thinking on my part – it is very much Rosenstein’s story, and not all stories overlap.

With any luck, this will be remedied when some of Sharm’s other pioneers have their own memoirs published!

All in all, this was a very satisfying read – anybody who’s been scuba diving in the Red Sea will enjoy it, and it’s absolutely essential for anybody with more than a passing familiarity with Sharm El Sheikh and the trials that the place and its people endured to become what it is today.

Paperback

Hardback

More great book reviews

• Review: Sharkpedia, A Brief Compendium of Shark Lore by Daniel C Abel
• The High Seas, by Olive Heffernan
• Many Things Under a Rock – The Mysteries of Octopuses, by David Scheel
• The Bathysphere Book by Brad Fox
• Britain’s Living Seas, by Hannah Rudd

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The Coral Triangle in the western Pacific Ocean is home to the greatest variety of marine life on the planet. In his latest book Coral Triangle Cameos, Alan J Powderham, with scientific consultant Sancia van der Meij, focuses on the ‘small majority’ – the diminutive yet vital and often overlooked inhabitants of this amazing world.

In the 12 fascinating chapters of Coral Triangle Cameos, Powderham and van der Meij look at everything from the smallest crustaceans hiding on the reef to the weird and wonderful life forms drifting in the open ocean on blackwater dives.

With Alan’s stunning photographs and extremely informative text, you are taken on a journey into a complex, interdependent marine world brimming with life.

In this extract from the amazing book we take a look at a selection of chapters and the beautiful images that accompany them.

MUSHROOM CLUB

The Fungiidae family – known as mushroom corals – are predominantly solitary single-polyp corals which may have multiple mouths. As with other Cnidaria, their tentacles are armed with stinging cells, called nematocysts.

As hexacorals, they form limestone structures to house their polyps. Their arms form a radial symmetry of six, though this geometry is not readily obvious. By comparison, the arrangement of the eight-tentacled polyps of octocorals is generally
quite plain to see.

Individual polyps of mushroom corals reach impressively large sizes, with some solitary species exceeding more than
25cm. While the juveniles start life anchored to the substrate by a stalk, most species are free-living as adults. I have occasionally seen them collect in large aggregations, a mobility which is quite at odds with our normal conception of corals’ sedentary lifestyle.

They are also able to right themselves if turned upside down, for example by wave action. However, beyond all the biology, a prime attraction is their wonderful abstract patterns and intricate structures.

CRYPTOBENTHIC CHARMERS

Cryptobenthic, which basically means ‘hidden on the bottom’, refers to the tiny, secretive fish which typically hide within the coral crevices and reef debris. Consequently, they are easily overlooked but are now considered to be key contributors to the viability of the reefs.

Recent research has focused on discovering the apparently huge deficit in the nutrients required to sustain the complex ecosystems of coral reefs.

The larvae of cryptobenthic fish are not broadcast but settle locally, thus creating a bounteous cycle of nutrition concentrated within the confines of the reef.

Blennies are prominent citizens of this community and are widely represented in tropical and temperate seas, with an estimated 350 species. They provide a variety of charming characters as they peer out from their hideaways with large, appealing eyes.

This description is qualified, since a sprinkling of the notorious fangblennies number among this family. Most blennies are herbivores but the fangblenny is the exception.

It operates in borrowed clothes, as it mimics cleaner fish. This enables it to approach and take a bite out of unsuspecting patrons attending cleaning stations.

SMART SQUID

Among invertebrates, cephalopods are widely admired for their intelligence. They match some of the smartest vertebrates, which is pretty impressive for a mollusc.

Yet, being molluscs, they have evolved along completely distinct pathways. Their brains are cited as prime examples of convergent evolution. A direct experience of this mental prowess was provided early in my introduction to diving in the Coral Triangle.

My interest, then, was predictably attracted by the more obviously impressive subjects such as dense shoals of large fish. Underwater, good photography generally demands close proximity to the subject – a familiarity not readily welcomed
by the creatures of the reef.

So I was delighted, when encountering a large shoal of barracuda, to find that my local dive guide was well versed in the correct procedure. He immediately signalled to me to avoid further approach, and wait while he circled deeper to take position on the far side of the shoal. From this manoeuvre he was able to shepherd the fish towards me.

So, it came as quite a surprise when he blankly refused to apply the same tactics when we happened upon a school of squid. ‘Squid, like cats – too smart – don’t herd like barracuda’ was his amusingly laconic but insightful explanation.

DECORATED DECEPTION

Decapod means ‘ten footed’. Such anatomy is clearly evident in the crab pictures below, despite their liberal decoration of stinging hydroids.

This living array of potent protection is also a transferable asset. Remarkably, a moulting crab will painstakingly transplant
its collection of hydroids to the new carapace. It is a delicate and precarious operation. It has to be undertaken during the period of heightened vulnerability while the crab’s new exoskeleton hardens.

The spider crab has also adopted a singular approach to decoration, specialising in corallimorpharians, which most
notably disguise the crab’s outline.

Decorator crabs have a covering of fibrous material armed with tiny hooks known as setae. These enable them to attach their adornments like Velcro.

ALIEN DRIFTERS

While the rich biodiversity of the Coral Triangle may readily overwhelm the senses, some bizarre transparent creatures may float by unnoticed.

As illustrated, these range from ctenophores to heteropods and even pelagic ascidians. Ascidians are typically sessile creatures and establish colonies that can spread extensively.

The brief phase of the ascidian tadpole is totally focused on settling, affording it no time to feed. Accordingly, they have no mouth but do possess a range of chordate components including a primitive spine, and rudimentary eyes and brain.

After settlement, these redundant body parts are all absorbed in a transformation that matches the terrestrial example of the caterpillar to butterfly metamorphosis. But for the ascidian, it is a case of losing rather than gaining mobility.

The larva, now attached to the substrate, transmutes into a vase-like form for which it promptly develops intake and exit siphons to continue life as a filter feeder.

Not all ascidians sacrifice mobility, as there are pelagic species known as pyrosomes which may be seen rolling over the substrate like aquatic tumbleweed.

Ctenophores are voracious predators and come in a range of shapes and body sizes. Like a tiny iridescent refugee from Star Trek, with its gut full of plankton, this comb jelly has clearly enjoyed a successful nocturnal hunt.

Heteropods, (first image below) known curiously as sea elephants though actually molluscs, virtually defy description.

More great reads from our Magazine

• Inspiring Hope – an interview with Cristina ‘Mitty’ Mittermeier
• Ross Merrin on training as a BDMLR Marine Mammal Medic
• Shark and Jolanda Reef – Howard Rosenstein on the day it all began…
• ‘Toxic Trumps’ – venomous sea creatures and how to treat their stings
• Are work-for-training scuba diving internships worth it?

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