BRAIN WAVES: UNDERSEA CORAL MAZES & LABYRINTHS


BRAIN CORAL Abaco Bahamas (Melinda Rogers / Dive Abaco)

BRAIN WAVES: UNDERSEA CORAL MAZES & LABYRINTHS

The most apposite description of brain coral Diploria labyrinthiformisis is essentially a no-brainer. How could you not call the creatures on this page anything else**. These corals come in wide varieties of shape and colour, and 4 types are found in Caribbean waters. They date from the Jurassic period.

BRAIN CORAL Abaco Bahamas (Melinda Rogers / Dive Abaco)

Each ‘brain’ is in fact a complex colony consisting of genetically similar polyps. These secrete CALCIUM CARBONATE which forms a hard carapace. This chemical compound is found in minerals, the shells of sea creatures, eggs, and even pearls. In human terms it has many industrial applications and widespread medicinal use, most familiarly in the treatment of gastric problems. 

BRAIN CORAL Abaco Bahamas (Melinda Rogers / Dive Abaco)

BRAIN CORAL Abaco Bahamas (Melinda Rogers / Dive Abaco)

The hardness of this type of coral makes it an important component of reefs throughout warm water zones world-wide. The dense protection also guarantees (or did until our generation began systematically to dismantle the earth) –  extraordinary longevity. The largest brain corals develop to a height of almost 2 meters, and are believed to be several hundred years old.

BRAIN CORAL Abaco Bahamas (Melinda Rogers / Dive Abaco)

BRAIN CORAL Abaco Bahamas (Melinda Rogers / Dive Abaco)

HOW ON EARTH DO THEY LIVE?

If you look closely at the cropped image below and other images on this page, you will see thousands of tiny tentacles nestled in the trenches on the surface. These corals feed at night, deploying their tentacles to catch food. Their diet consists of tiny creatures and their algal contents. During the day, the tentacles retract into the sinuous grooves. Some brain corals have developed tentacles with defensive stings. 

BRAIN CORAL Abaco Bahamas (Melinda Rogers / Dive Abaco)

THE TRACKS LOOKS LIKE MAZES OR DO I MEAN LABYRINTHS?

The difference between mazes and labyrinths is that labyrinths have a single continuous path which leads to the centre. As long as you keep going forward, you will get there eventually. You can’t get lost. Mazes have multiple paths which branch off and will not necessarily lead to the centre. There are dead ends. Therefore, you can get lost. Or never get to the centre at all. 

** On the corals shown here, you will get lost in blind alleys almost at once. Therefore in human terms these are mazes. The taxonomic labyrinthiformisis is Latin derived from Greek, and applied generally to this kind of structure, whether in actual fact a labyrinth or a maze.

BRAIN CORAL Abaco Bahamas (Melinda Rogers / Dive Abaco)

CREDIT: all amazing underwater brain-work thanks to Melinda Rogers / Dive Abaco; Lucca Labyrinth, Keith Salvesen / Rolling Harbour

Here is a beautiful inscribed labyrinth dating from c12 or c13 from the porch of St Martin’s Cathedral in Lucca, Italy. Very beautiful but not such a challenge.

Labyrinth (Maze), Porch Lucca Cathedral (Keith Salvesen)

BRAIN CORAL Abaco Bahamas (Melinda Rogers / Dive Abaco)

CARIBBEAN REEF SQUID: SUPERPOWERS & SQUID SEX


Caribbean Reef Squid, Bahamas (Melinda Riger / G B Scuba)

CARIBBEAN REEF SQUID: SUPERPOWERS & SQUID SEX  

The Caribbean reef squid Sepioteuthis sepioidea is a small squid species of (mainly) the Caribbean Sea and the Floridian coast, and the most common in its range. These squid tend to form small shoals in and around reefs. From now on and through the summer would be a good time to investigate.

Caribbean Reef Squid, Bahamas (Melinda Riger / G B Scuba)

Squid are voracious eaters, dragging their prey to their mouths with some or all of their 10 limbs and using their beak to cut it up. The target species are small fish, molluscs and crustaceans. The squid have a ‘raspy tongue’ known as a radula which further breaks up the food for easy consumption.

Caribbean Reef Squid, Bahamas (Melinda Riger / G B Scuba)

REEF SQUID SUPERPOWERS (SUPERCOOL)

  • Squid are capable of brief flight out of the water (a fairly recent discovery)
  • They can also hide from / confuse predators by ejecting a cloud of black ink
  • Squid can change colour, texture and shape, and can even match their surroundings
  • This enviable power is used defensively as camouflage or to appear larger if threatened
  • It is also used in courtship rituals (something that humans might find disconcerting)
  • Colour patterns are also used for routine squid-to-squid communication AND GET THIS:
  • A squid can send a message to another on one side & a different one to a squid on its other side

Caribbean Reef Squid, Bahamas (Melinda Riger / G B Scuba)

SQUID SEX (1) “ROMANCING THE SQUID”

  • A male will gently stroke a female with his tentacles
  • The female will (most likely) flash an ‘alarm’ pattern. She’s playing hard to get.
  • The male soothes her (don’t try this at home, guys) by blowing and jetting water at her
  • If this doesn’t go well, he’ll move off, then repeat the routine until she sees his good points
  • However this on / off courtship can last for hours until at last he succeeds and then…
  • … he attaches a sticky packet of sperm onto the female’s body (romance is not dead on the reef)
  • She then reaches for it and moves it to her seminal receptacle
  • Meanwhile he stays close, emitting a pulsing pattern, as well he might after all that palaver
  • She then finds a safe place to lay her eggs. Job done. **

Caribbean Reef Squid, Bahamas (Melinda Riger / G B Scuba)

SQUID SEX (2) IT ALL ENDS BADLY. VERY BADLY.

  • As soon the female squid has laid her eggs, she usually dies soon after
  • Male squid live a bit longer and… may have other packets to stick on other lady squid
  • But then in the end he dies too
  • It’s all horribly reminiscent of Romeo and Juliet. The lovers die in the end (but there’s no romantic balcony scene first)

Caribbean Reef Squid, Bahamas (Melinda Riger / G B Scuba)

THE CORRECT PLURAL OF SQUID

I had an unwise look online, always a hotbed of conflicting opinions. Inserting an algorithm into the interstices of the internet proves conclusively that the plural of squid is… squid. One squid, ten squid, a group of squid, a plate of squid. Unless, that is, you are talking about more than one of the many squid species, when you could possibly say ‘I collect both reef and giant squids’. “Squidses” sounds fun but is sadly not permitted.

RELATED POST (from the past): THE PLURAL OF OCTOPUS

Caribbean Reef Squid, Bahamas (Melinda Riger / G B Scuba)

** For an excellent article about squid including the intricate details of courtship and reproduction (and an image of a squid penis) check out  SQUID WIKI 

Credits: Fabulous underwater pics – Melinda Riger of Grand Bahama Scuba; research sources include MarineBio; Animal Diversity Web (Michigan Uni); and Wiki, which comes into its own in some fields of natural history where experts write the entry)

FAIRY BASSLET (‘MIND YOUR GRAMMA’): BAHAMAS REEF FISH


fairy-basslet-melinda-riger-g-b-scuba-copy-2

FAIRY BASSLET (‘MIND YOUR GRAMMA’): BAHAMAS REEF FISH (33)

The Fairy Basslet is a tiny brightly-coloured fish with a pretentious alternative name. It is otherwise known as the Royal Gramma (Gramma loreto). These fish are found  in the coral reefs of the (sub)tropical western Atlantic. They are also found in aquariums anywhere you like, being small, bright, placid and generally good-natured.

fairy-basslet-melinda-riger-gb-scuba

Conveniently, the basslet is unlikely to be confused with any other species. Its striking two-tone colour scheme of purple and yellow is hard to miss. The purple front half (which is presumably where the ‘royal’ comes from, being a regal or imperial colour) may also be violet or even blue in some fish and / or in some light conditions. Another identification pointer is a black spot on the dorsal fin. 

fairy-basslet-melinda-riger-grand-bahama-scuba

You’ll notice that the basslet above appears to be upside down. Which is because it is – this isn’t an inadvertent photo-flip. These little fish tend to orientate themselves to be parallel with the closest surface. This leads to them happily swimming upside down, or aligning vertically. As one article I read says severely, “this behaviour is not to be mistaken for illness”.

fairy-basslet-melinda-riger-g-b-scuba

Fairy basslets / royal grammas are also CLEANER FISH. They pick parasites and dead skin off larger fish that visit so-called cleaning stations to be attended to by tiny fish and cleaner shrimps, and in some instances to have their gills and even their teeth cleaned. The deal is that, in return, the large fish do not eat the cleaners. Even snack-sized ones rootling around inside their mouths.

fairy-basslet-melinda-riger-gb-scuba

 WHAT ABOUT BREEDING?
I really can’t improve on this rather touching description from Wiki: “The male will build the nest among rocks using pieces of algae. The male will then lead the female to the nest, where she will deposit 20-100 eggs in the nest. During the breeding period, this behaviour is repeated almost every day for a month or longer (my italics). The eggs are equipped with small protuberances over the surface with tiny threads extending from them which hold onto the algae of the nest and keep the eggs in place. The eggs will hatch in five to seven days, normally in the evening…”

fairy-basslet-melinda-riger-gb-scuba

HOW COME THE NAME ‘GRAMMA LORETO’?

This official name became a brainworm with me after I started this post. I had to check it out. The ‘Gramma’ part is unrelated to the fond name for a grandmother; rather, it simple denotes a member of the genus of fishes in the family Grammatidae.

The Loreto part is more mysterious. It is an an ancient town in Italy; and the name of several British schools, including – almost too good to be true – a school called Loreto Grammar. In a nutshell, the link between the town and places of education is that the Sisters of Loreto, founded in the c17 and named for a shrine in the Italian village, are dedicated to education in their Ministry.

How that ties in with a tiny Caribbean reef fish, I have yet to find out. I probably never will… Here’s a short video to alleviate the disappointment.

I failed to be able to resist finding out whether any country of the world has a purple and yellow flag. The answer is, no. However I am delighted to be able to report that the flag of the Independent Party of Uruguay is basslet-coloured.

inependent-party-uruguay-flag

fairy-basslet-melinda-riger-g-b-scuba-copy

Credits: all fantastic photos by Melinda Riger of Grand Bahama Scuba; magpie pickings of an unacademic sort for facts and speculation

ELKHORN CORAL – REEF LIFE . ABACO . BAHAMAS


 

Elkhorn Coral, Abaco Bahamas (Melinda Rogers / Dive Abaco)

ELKHORN CORAL (Acropora palmata) is a widespread reef coral, an unmistakeable species with large branches that resemble elk antlers. The dense growths create an ideal shady habitat for many reef creatures. These include reef fishes of all shapes and sizes, lobsters, shrimps and many more besides. Elkhorn and similar larger corals are essential for the wellbeing both of the reef itself and also its denizens. These creatures in turn benefit the corals and help keep them in a healthy state.

Elkhorn Coral, Abaco Bahamas (Melinda Rogers / Dive Abaco)

Examples of fish species vital for healthy corals include several types of PARROTFISH, the colourful and voracious herbivores that spend much of their time eating algae off the coral reefs using their beak-like teeth. This algal diet is digested, and the remains excreted as sand. Tread with care on your favourite beach; in part at least, it will consist of parrotfish poop.

Elkhorn Coral, Abaco Bahamas (Melinda Rogers / Dive Abaco)

Elkhorn Coral, Abaco Bahamas (Melinda Rogers / Dive Abaco)

Other vital reef species living in the shelter of elkhorn and other corals are the CLEANERS, little fish and shrimps that cater for the wellbeing and grooming of large and even predatory fishes. Gobies, wrasse, Pedersen shrimps and many others pick dead skin and parasites from the ‘client’ fish including their gills, and even from between the teeth of predators. This service is an excellent example of MUTUALISM, a symbiotic relationship in which both parties benefit: close grooming in return for rich pickings of food.

Elkhorn Coral, Abaco Bahamas (Melinda Rogers / Dive Abaco)

VULNERABILITY TO CLIMATE CRISIS

Formally abundant, over the course of just a couple of decades elkhorn coral (along with all reef life) has been massively affected by climate change. We can all pinpoint the species responsible for much of the habitat decline and destruction, and the primary factors involved. In addition, global changes in weather patterns result in major storms that are rapidly increasing in both frequency and intensity worldwide.  

Elkhorn Coral, Abaco Bahamas (Melinda Rogers / Dive Abaco)

Physical damage to corals may seriously impact on reproductive success: elkhorn coral is no exception. The effects of a reduction of reef fertility are compounded by the fact that natural recovery is in any case inevitably a slow process. The worse the problem gets, the harder it becomes even to survive, let alone recover, let alone increase. 

Elkhorn Coral, Abaco Bahamas (Melinda Rogers / Dive Abaco)

HOW DOES ELKHORN CORAL REPRODUCE?

There are two types of reproduction, which one might call asexual and sexual:

  1. Elkhorn coral reproduction occurs when a branch breaks off and attaches to the substrate, forming a the start of a new colony. This process is known as Fragmentation and accounts for roughly half of coral spread. Considerable success is being achieved now with many coral species by in effect farming fragments and cloning colonies (see Reef Rescue Network’s coral nurseries)
  2. Sexual reproduction occurs once a year in August or September, when coral colonies release millions of gametes by Broadcast Spawning 

Elkhorn Coral, Abaco Bahamas (Melinda Rogers / Dive Abaco)

All photos: Melinda Rogers, with thanks as ever for use permission

Elkhorn Coral, Abaco Bahamas (Melinda Rogers / Dive Abaco)

WTF? (WHAT’S THAT FISH?): THE FROGFISH


Frogfish (Adam Rees, Scuba Works)

WTF? (WHAT’S THAT FISH?): THE FROGFISH

I have just been lightly involved in a long online thread showcasing the weirdest / most science fiction-y creatures around the world. Trust me, there are plenty. There were quite a few duplications. My own contribution was the frogfish, which no one else had nominated. They are so special – and so weird – that I am reposting my article about them. Don’t miss the last video!

frogfish-anglerfisch

This ‘WTF?’ series started with a relatively conventional species, the REMORA. It has been getting progressively more bizarre. We moved onto an omnium gatherum of WEIRDO FISHES, then the remarkable LETTUCE SEA SLUG, and most recently the BATFISH. Time to ramp up the stakes: with many thanks to scuba expert Adam Rees for use permission for his terrific photos, I present… the FROGFISH.

Frogfish (Adam Rees, Scuba Works)

The frogfish is a kind of anglerfish found in almost all tropical and subtropical oceans and seas. There are about 50 different species worldwide, covering an astonishing range of strange appearances. They generally live on the sea floor around coral or rock reefs. In size they vary from tiny to about 15 inches long – although ‘long’ is a flexible concept because they are to an extent shape-changers in height and width.Frogfish (Adam Rees Scuba Works)

FROGFISH SUPERPOWERS YOU MAY WISH TO HAVE

  • INVISIBILITY CLOAK . Frogfish are masters of disguise and camouflage. This enables them to catch their prey with minimal effort and also to avoid predators. Their camouflage methods – broadly known as ‘aggressive mimicry’ – include
    • Ability to change colour for days or even weeks to mimic their surroundings
    • Getting covered in algae and other organic matter that matches their habitat or
    • Looking inherently like a plump rock or in some cases, plant

Fear for the life of the spider crabFrogfish (Adam Rees, Scuba Works)

  • IRRESISTIBLE ATTRACTION
    • A sort of frontal dorsal fin called an illicium to which is attached a
    • Lure called an esca which may mimic a worm, shrimp or small fish etc and which is
    • Retractable in many species and
    • Regenerates if it gets mislaid

The ‘dollop of cream’ thing is the esca. Note the characteristic large mouthFrogfish (Adam Rees, Scuba Works)

Spot the escaFrogfish (wiki)

  • BUOYANCY CONTROL & SHAPE-SHIFTING
    • Most frogfish have a ‘gas bladder’ to control their buoyancy.
    • Some species can change shape or even inflate themselves by sucking in quantities of water in a so-called defensive ‘threat display’.

frogfish-black

Frogfish (Adam Rees Scuba Works) Frogfish (Adam Rees Scuba Works)

HOW DO FROGFISH REPRODUCE? 

Although not conventionally attractive creatures, frogfish clearly manage to reproduce. Little is known about the techniques in the wild, but one is probably ‘with care’, especially for a male frogfish who may not survive for long if he hangs around after fertilisation has taken place. It has been noted that females tend to select far smaller males to fertilise their huge numbers of eggs, perhaps for that very reason.

Frogfish (Adam Rees, Scuba Works)

FROGFISH FEEDING SKILLS – GOOD OR BAD?

When deploying the lure, potential prey that comes too close to that wide mouth stands no chance. A frogfish will strike in a fraction of a second. Frogfishes have voracious appetites for crustaceans, other fish, and even each other. I can do no better than borrow this vivid description of a feeding frogfish:

“When potential prey is first spotted, the frogfish follows it with its eyes. Then, when it approaches within roughly seven body-lengths, the frogfish begins to move its illicium in such a way that the esca mimics the motions of the animal it resembles. As the prey approaches, the frogfish slowly moves to prepare for its attack; sometimes this involves approaching the prey or “stalking” while sometimes it is simply adjusting its mouth angle. The catch itself is made by the sudden opening of the jaws, which enlarges the volume of the mouth cavity up to twelve-fold, pulling the prey into the mouth along with water. The attack can be as fast as 6 milliseconds. The water flows out through the gills, while the prey is swallowed and the oesophagus closed with a special muscle to keep the victim from escaping. In addition to expanding their mouths, frogfish can also expand their stomachs to swallow animals up to twice their size.

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HOW DO FROGFISHES GET AROUND? SWIM? WALK? CRAWL?

Frogfishes do not in fact move around a great deal. Using their camo advantages, they prefer to lie on the sea floor and wait for prey to come to them. As mentioned in the quote above, they may slowly approach prey using their pectoral and pelvic fins to “walk” along the sea bottom. They can swim using their tail fin (or in some species by simple ‘jet propulsion’ by forcing water out of their gills) but rarely do so – they don’t feed on the move, and they are adapted to the sea floor environment where they food is readily available. However their “walking” ability is limited to short distances.

frogfish-anglerfisch

DO FROGFISH HAVE OTHER COLOUR SCHEMES?

Indeed they do. In stark contrast to the camo species, some frogfishes are highlighter bright. Here are two of my favourite photos by Adam that show this clearly. I’ve no idea if these are a male and female. I suspect they are different species. I think the brown one is a striated frogfish and the other is… a yellow frogfish. Some people keep these creatures in  aquaria, but apparently it is impossible to sex them, and they have to be kept on their own for everyone’s peace of mind…

Frogfish (Adam Rees Scuba Works) Frogfish (Adam Rees Scuba Works)

FROGFISH INFOGRAPHICS

frogfishFrogfish Infographic 'Monsters of the Deep'

FROGFISH VIDEOS

These two videos, from Lester Knutsen and Daan Van Wijk respectively, show some of the characteristics I have written about above. Both are short and both are fascinating.

To read more about frogfishes and for some fabulous photos I highly recommend the website FROGFISH.CH You can reach the main page(s) but the link seem to be broken so I have not been able to contact Teresa Zubi, whose site it is. She clearly has a sense of humour and uses a neat pair of gifs which I hope she won’t mind my using…

Credits: All main photos, Adam Rees  of Scuba Works with many thanks; wiki for ‘spot the esca’, red quote & basic info; videos Lester Knutsen & Daan Van Wijk; Teresa Zubi for website & gifs; infographics, authors u/k

Frogfish Tee Shirt

SPERM WHALE CALF, ABACO, BAHAMAS: WHY WORLD WHALE DAY MATTERS


Sperm Whale baby (neonate) Abaco Bahamas (Charlotte Dunn / BMMRO)

WORLD WHALE DAY 2022

NEONATE SPERM WHALE CALF, ABACO, BAHAMAS

 

After many decades of the savage depletion of the global whale population, the tide turned in their favour in the 1960s. It was fair to assume that, gradually, a new era of cetacean recovery must follow and that whales would be accorded the respect they deserve. Over time, many organisations were formed with the specific aim of protecting and conserving marine mammals, the Bahamas Marine Mammal Research Organisation (BMMRO) based on Abaco among them.

The struggle to fulfil that aim in the face of entirely man-made environmental damage has become increasingly difficult. However, there have more recently been encouraging reports of population recovery in some seas, a good reason to celebrate WORLD WHALE DAY and to consider supporting the many organisations that work to preserve marine mammals. 

The photographs and the 2 very moving videos below are of an adult sperm whale and new-born calf. They were taken by BMMRO in Bahamas waters. There’s optimism in these images. I’d like to think that a smiling baby whale holds out hope for the future. Hopefully it will flourish and live for decades. If it does not, the overwhelmingly likely cause will be mankind, either directly or indirectly.

Sperm Whale baby (neonate) Abaco Bahamas (Charlotte Dunn / BMMRO)

Sperm Whale baby (neonate) Abaco Bahamas (Charlotte Dunn / BMMRO)

Sperm Whale baby (neonate) Abaco Bahamas (Charlotte Dunn / BMMRO)

Sperm Whale baby (neonate) Abaco Bahamas (Charlotte Dunn / BMMRO)

CREDITS: Close-up footage plus the clips I have taken from it – Charlotte Dunn / Diane Claridge / BMMRO 

DONATE: If you are touched by the magic of this little Bahamas sperm whale, may I invite you to consider making a donation to BMMRO for its research and conservation work – a scientific commitment that reaches far beyond the waters of the Bahamas. The system is set up to process donations from just $10 upwards, and every cent is used to further the work of BMMRO. Please click the logo below to reach the right page directly.

ABSORBING SPONGES ON THE BAHAMAS REEFS…


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ABSORBING SPONGES ON THE BAHAMAS REEFS…

It is a rather special and indeed specialist day today: it is #spongethursday, a component of the 11th World Sponge Conference (I’d add the logo, but it closely resembles a pink Covid symbol). Poriferaphiles everywhere should be celebrating these beautiful creatures today. Here are some gorgeous examples. Now you know why sponges deserve a day of their own.

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Candelabra Songe (with brittle stars attached)candelabra-sponge-melinda-riger-g-b-scubasponge-melinda-riger-g-b-scuba

Black Ball Spongesblack-ball-sponge-melinda-riger-g-b-scuba-copy

One for Valentine’s Dayheart-shaped-sponge-melinda-riger-gb-scuba

Vase Spongesvase-sponge- pink-melinda-riger-gb-scubavase-sponge-melinda-riger-g-b-scuba

sponges-and-coral-on-the-reef

Spawning Brown Encrusting Spongebrown-encrusting-sponge-spawning-melinda-riger-g-b-scuba

All photos: Melinda Riger, Grand Bahama Scuba – with thanks as ever

HERMIT CRABS: SHELL-DWELLERS WITH MOBILE HOMES


Hermit Crab, Abaco Bahamas (Keith Salvesen / Rolling Harbour)

HERMIT CRABS: SHELL-DWELLERS WITH MOBILE HOMES

As everyone knows, Hermit Crabs get their name from the fact that from an early age they borrow empty seashells to live in. As they grow they trade up to a bigger one, leaving their previous home for a smaller crab to move into. It’s a benign** chain of recycling that the original gastropod occupant would no doubt approve of, were it still alive… The crabs are able to adapt their flexible bodies to their chosen shell. Mostly they are to be found in weathered (‘heritage’) rather than newly-empty shells for their home. [**except for fighting over shells] 

Hermit Crab, Abaco Bahamas (Keith Salvesen / Rolling Harbour)

 HERMIT CRAB FACTS TO ENLIVEN YOUR CONVERSATION

  • The crabs are mainly terrestrial, and make their homes in empty gastropod shells
  • Their bodies are soft, making them vulnerable to predation and heat.
  • They are basically naked – the shells protect their bodies & conceal them from predators
  • In that way they differ from other crab species that have hard ‘calcified’ shells / carapaces
  • Ideally the shell should be the right size to retract into completely, with no bits on display

Hermit Crab, Abaco Bahamas (Keith Salvesen / Rolling Harbour)

  • As they grow larger, they have to move into larger and larger shells to hide in
  • As the video below shows wonderfully, they may form queues and upsize in turns
  • Occasionally they make a housing mistake and chose a different home, eg a small tin

Hermit Crab, Abaco Bahamas (Keith Salvesen / Rolling Harbour)

  • The crabs may congregate in large groups which scatter rapidly when they sense danger
  • The demand for suitable shells can be competitive and the cause of inter-crab battles
  • Sometimes two or more will gang up on a rival to prevent its move to a particular shell

HERMIT CRABS CAN EVEN CLIMB TREES – WITH THEIR SHELLS ON TOO

Hermit Crab, Abaco Bahamas (Tom Sheley)

HERMIT CRABS EXCHANGING HOMES with DAVID ATTENBOROUGH

This is a short (c 4 mins) extract from BBC Earth, with David Attenborough explaining about the lives and habits of these little crabs with his usual authoritative care and precision . If you have the time I highly recommend taking a look.

Credits: All photos taken on Abaco by Keith Salvesen except for the tree-climber crab photographed by Tom Sheley; video from BBC Earth

Hermit Crab, Abaco Bahamas (Keith Salvesen / Rolling Harbour)

COOKIECUTTER SHARKS: BEASTLY LITTLE SUCKERS


Cookiecutter Shark mouth, jaws & teeth (BMMRO Bahamas)

COOKIECUTTER SHARKS

BEASTLY LITTLE SUCKERS

The Cookiecutter shark Isistius brasiliensis (aka the less scary, more genial sounding ‘cigar shark’), might be an ideal candidate for a Room 101 nemesis.** These little beasts – a species of dogfish shark – are found in several mainly island-based areas dotted around the globe, including in Bahamas waters.

 

HOW COME THE NAME?
These sharky little b@st@rds (*scientific term*) attack marine mammals and fishes, attaching themselves by suction and gouging out perfect round plugs of skin and flesh, leaving what are sometimes called ‘crater wounds’. Then they eat them. Imagine getting hold of a really sharp domestic cookie cutter with circular rows of razor-sharp teeth, and grinding it hard into your thigh. There! That! 
The size of an adult shark:16″ max
The term ‘cookiecutter’ is also a pejorative slang term, meaning mass-produced, lacking in originality, or boringly samey, as in cookiecutter cars or TV genres etc. The little critters under consideration here are anything but…
                        

HORRIFYING COOKIECUTTER FACTS

  • Live in the depths, rise vertically in the day & dive back down at dusk
  • Undersides have light-emitting ‘photophores’ which emphasise…
  • …the dark collar which acts as a lure, resembling a small innocent fish
  • Bioluminescence lures prey & confuses predators (more on this below)
  • The glow is so strong it may last for some time after removal from water

  • Their lips are ‘suctorial’ = they attach tightly to their target
  • The jaws then gouge out the victim’s flesh in a remarkably neat circle
  • Omni-vicious: any medium to large ocean creature is vulnerable to attack
  • There are even occasional reports of humans being targeted

Here are two Blainville’s beaked whales that I photographed from the BMMRO research vessel. The top whale has a number of circular healed attack marks and a recent one. You can see how deep the gouged hole is. The other has well-healed scars.

Blainville's Beaked Whale - cookiecutter shark damage (Keith Salvesen)Blainville's Beaked Whale - cookiecutter shark damage (Keith Salvesen)

  • Multi-toothed: top rows of small teeth, rows of larger teeth on the bottom
  • The lower teeth are the cutters, acting like a saw when locked on
  • See header image and below for full details

    

HOW EXACTLY DO THEY DO WHAT THEY DO?
I can explain it no better than the renowned authority Prof. W. K. P. Dear:  “the suctorial lips ensure a tight seal. It then bites, using its narrow upper teeth as anchors while its razor sharp lower teeth slices into the prey. Finally, the shark twists and rotates its body to complete a circular cut, quite possibly aided by the initial forward momentum and subsequent struggles of its prey. The action of the lower teeth may also be assisted by back-and-forth vibrations of the jaw, a mechanism akin to that of an electric carving knife”.

                 ARE THESE SHARKS ‘PARASITES’, WOULD YOU SAY?

The behaviour of these sharks is an example of a symbiotic relationship between two species that is parasitic. This means essentially that one gains and the other suffers (eg humans & no-see-ums). This is distinct from commensalistic symbiosis, where one species gains and the other is unaffected (e.g. cattle egrets with cattle); and mutualistic symbiosis, where both gain (e.g. cleaner fish & groupers). So, in a word, yes.

  • An ‘ambush predator’: these little sharks ‘hover’ in the water column waiting…
  • They are capable of rapid movement to catch up & latch onto prey
  • They will eat a passing small fish, crustacean or even squid as a snack
  • Sometimes they operate in schools; there is safety in numbers
  • The schools are thought to increase the ‘lure’ effect of the dark collar

A beached whale that’s been heavily targeted

FUN FACT TO COUNTERACT THE BAD STUFF

In the late c20, more than 30 U.S. Navy submarines were forced back to base to repair damage caused by cookiecutter shark bites, either to the neoprene footings of sonar domes or to rubber-sheathed cables. The problems were solved by using fibreglass. Oceanographic equipment and telecommunications cables are also recorded as being damaged by these sharks.

Cookiecutter Shark – the real deal

MONSTERS OF THE DEEP

These great cards from the weirdly spelled WIERD ‘N’ WILD CREATURES provide excellent factual info. Their CCS card is no exception. You’ll find more details here about the effect of the bioluminescence and so on, written as clearly as I might hope to. 

Cookiecutter Shark Facts (Monsters of the Deep)Cookiecutter Shark Facts (Monsters of the Deep)

** “The worst thing in the world varies from individual to individual. It may be burial alive or death by fire, or by drowning, or by impalement, or fifty other deaths. There are cases where it is some quite trivial thing, not even fatal.” (George Orwell, 1984). Being in a tank with some cookiecutters might count.

Alright now… the wounds eventually healBlainville's Beaked Whale - cookiecutter shark damage (Keith Salvesen)

Credits: BMMRO – header image; beaked whale photos – Keith Salvesen / BMMRO; Te Ara NZ for the main jaw image; all small images with thanks to Wiki and respective photographers who took the time to upload them for all to enjoy & learn from; ‘wierdnwonderful creatures’ for the monster card; range map from Wiki

IS THIS THE REAL LIFE? IS THIS JUST FANS AT SEA?


Purple sea fan, Bahamas (Melinda Riger / Grand Bahama Scuba)

IS THIS THE REAL LIFE? IS THIS JUST FANS AT SEA?

I am re-posting this sea fan article as 2021 rolls over into 2022 with much the same disruption, anxiety, and (for many) grief that we were all facing a year ago. The converse and somewhat rhapsodic title reflects the experience of many people since Covid engulfed the world. Life has become simultaneously real and surreal. It continues in many respects as normal yet who would have guessed that as we entered a new decade in 2020, the face mask would quickly become an essential (or anyway a medically recommended) part of daily life and remain so? 

This post was written at a time of sunshine, normality and optimism, before Covid and even before the violent destructive force of Dorian in autumn 2019. Here’s some cheer from sea fans on the coral reefs of the Bahamas.  

GALLERY OF GORGONIANS 

Purple Sea Fans, Abaco, Bahamas (Dive Abaco / Keith & Melinda Rogers)

The waters of Abaco teem with myriads of fish that depend on the coral reefs for shelter and safety, for breeding, for growing up in, and for nourishment. Sea fans (or gorgonians, to use the technical name) are animals too. They may look like plants and stay rooted to the spot, but like anemones these ‘soft corals’ are creatures of the reef and essential indicators of its health.

Purple sea fan, Bahamas (Melinda Riger / Grand Bahama Scuba)

Purple sea fan, Bahamas (Melinda Riger / Grand Bahama Scuba)

The purple sea fan Gorgonia ventalina (classified by Linnaeus in 1785) is one of the most common species of sea fan, and a spectacular one at that. The main branches are linked by a lattice of smaller branches. Below the ‘skin’ is a skeleton made of calcite compounded with a form of collagen.

Purple sea fan, Bahamas (Melinda Riger / Grand Bahama Scuba)

Purple Sea Fans, Abaco, Bahamas (Dive Abaco / Keith & Melinda Rogers)

Sea fans are filter-feeders, and have polyps with eight tiny tentacles that catch plankton as it drifts past. They develop so that their orientation is across the prevailing current. This maximises the water passing by and consequently the supply of food as the fans gently wave in the flow.

Purple Sea Fans, Abaco, Bahamas (Dive Abaco / Keith & Melinda Rogers)

Purple Sea Fans, Abaco, Bahamas (Dive Abaco / Keith & Melinda Rogers)

Gorgonians have a chemical defence mechanism that protects against potential troublemakers. The main effect is to make themselves unpleasant to nibble or uproot.

Purple Sea Fans, Abaco, Bahamas (Dive Abaco / Keith & Melinda Rogers)

One species impervious to this deterrent is the fascinating FLAMINGO TONGUE SNAIL. Other ‘safe’ species include the fireworm and BUTTERFLYFISHES.

Purple Sea Fans, Abaco, Bahamas (Dive Abaco / Keith & Melinda Rogers)

One benefit of sea fans to mankind is that their defensive chemicals have been discovered to provide the basis for drug research and development, specifically in the field of  anti-inflammatories. Another benefit, of course, is that they are very beautiful to look at. And in bad times, that can only be good .

Purple Sea Fans, Abaco, Bahamas (Dive Abaco / Keith & Melinda Rogers)

Purple Sea Fans, Abaco, Bahamas (Dive Abaco / Keith & Melinda Rogers)

Credits: these wonderful photos were taken by Melinda & Keith Rodgers / Dive Abaco, Marsh Harbour; and Melinda & Fred Riger / Grand Bahama Scuba. Huge thanks to them all for allowing me to freely use their skilful underwater photography in this blog for the best part of a decade.

A SPECIAL FAN FOR A HAPPY AND HOPEFUL 2022

Purple Sea Fans, Abaco, Bahamas (Dive Abaco / Keith & Melinda Rogers)

BAHAMAS DOLPHINS: VIEW FROM A RESEARCH BOAT with BMMRO


Recent weather conditions have mostly been perfect for launching the new BMMRO boat and continuing with ongoing marine mammal research. The field work at the moment is one aspect of the ‘Saving Abaco’s Dolphins after Hurricane Dorian’ project.

Acoustic research involves deploying specialised recorders to monitor sub-surface noise levels such as ship-generated sound. This helps to determine the effects of underwater noise pollution on marine mammals. Areas of concern can be identified and monitored. Naturally the dolphins take a keen interest as well, and there is plenty of opportunity to enjoy their company out on the water.

More general research includes compiling intricate records of dolphins encountered, noting specific characteristics. The dorsal fin is generally the most helpful ID marker, as they are all different – especially when there is some wear and tear to go by.

BMMRO records for dolphins go back a long way, and often involve two or more generations of the same family. Amazingly, during the last few days, a dolphin was encountered whose mother was first seen as a calf in 1992…

BMMRO are hosting a meeting in Hope Town to explain recent work and its results

BMMRO intern Jaylen gets to admire dolphins at close quarters in the Sea of Abaco

Dolphin Research . Sea of Abaco . Bahamas . BMMRO – all photos © BMMRO

FLAMINGO TONGUE SNAILS: DECORATIVE CORAL-DWELLERS


Flamingo Tongue Snails (Melinda Rogers, Dive Abaco, Bahamas)

FLAMINGO TONGUE SNAILS: DECORATIVE CORAL-DWELLERS

FLAMINGO TONGUE SNAILS Cyphoma gibbous are small marine gastropod molluscs related to cowries. The living animal is brightly coloured and strikingly patterned, but that colour only exists in the ‘live’ parts – the so-called ‘mantle’. The shell itself is usually pale, and characterised by a thick ridge round the middle. These snails live in the tropical waters of the Caribbean and the wider western Atlantic. Whether alive or dead, they are gratifyingly easy to identify.

Flamingo Tongue Snails (Melinda Rogers, Dive Abaco, Bahamas)

THE IMPORTANCE OF CORAL

Flamingo tongue snails feed by browsing on soft corals. Often, they will leave tracks behind them on the coral stems as they forage (see image below). But corals are not only food – they provide the ideal sites for the creature’s breeding cycle.

Flamingo Tongue Snails (Dive Abaco, Bahamas)Flamingo Tongue Snails (Melinda Rogers, Dive Abaco, Bahamas)

Adult females attach eggs to coral which they have recently fed upon. About 10 days later, the larvae hatch. They eventually settle onto other gorgonian corals such as Sea Fans. Juveniles tend to live on the underside of coral branches, while adults are far more visible and mobile. Where the snail leaves a feeding scar, the corals can regrow the polyps, and therefore the snail’s feeding preference is generally not harmful to the coral.

The principal purpose of the patterned mantle of tissue over the shell is to act as the creature’s breathing apparatus. The tissue absorbs oxygen and releases carbon dioxide. As it has been (unkindly?) described, the mantle is “basically their lungs, stretched out over their rather boring-looking shell”

Flamingo Tongue Snails (Melinda Rogers, Dive Abaco, Bahamas)

THREATS AND DEFENCE

The species, once common, is becoming rarer. The natural predators include hogfish, pufferfish and spiny lobsters, though the spotted mantle provides some defence by being rather unpalatable. Gorgonian corals contain natural toxins, and instead of secreting these after feeding, the snail stores them. This supplements the defence provided by its APOSEMATIC COLORATION, the vivid colour and /or pattern warning sign to predators found in many animal species.

Flamingo Tongue Snails (Melinda Rogers, Dive Abaco, Bahamas)

MANKIND’S CONTRIBUTION

It comes as little surprise to learn that man is now considered to be the greatest menace to these little creatures, and the reason for their significant decline in numbers. The threat comes from snorkelers and divers who mistakenly / ignorantly think that the colour of the mantle is the actual shell of the animal, collect up a whole bunch from the reef, and in due course are left with… dead snails and “boring-looking shells” (see photos below). Don’t be a collector; be a protector…

Flamingo Tongue Snails (Melinda Rogers, Dive Abaco, Bahamas)

The photos below are of nude flamingo tongue shells from the Delphi Club Collection. Until I read the ‘boring-looking shell’ comment, I believed everyone thought they were rather lovely… I did, anyway. You decide!

Flamingo Tongue Snail Shell, Keith Salvesen AbacoFlamingo Tongue Snail Shell, Keith Salvesen Abaco

Image Credits:  Melinda Rogers / Dive Abaco; Keith Salvesen / Rolling Harbour

Flamingo Tongue Snails (Melinda Rogers, Dive Abaco, Bahamas)

ATLANTIC SPOTTED DOLPHINS . ABACO BAHAMAS


Atlantic Spotted Dolphins . Abaco Bahamas . BMMRO

ATLANTIC SPOTTED DOLPHINS – ABACO, BAHAMAS

There’s never ever a wrong time for dolphins to have some fun in the water. It’s what they expect. It’s what we (if we are lucky enough to see them) expect. It’s what they expect that we expect if we are out in a boat – hence the joyful bow-riding, the rapid crossing back and forth. From time to time there’s a single dolphin in a group that takes the opportunity to show off. In the deeper water off the southern tip of Abaco, in sight of the lighthouse, this is a good example of such carefree behaviour.

There’s more excitement to be found in this group. If you look carefully at #3 in the gallery, you’ll see a very small dorsal fin. There’s a calf in the group, being guided and watched over by two adults. Imagine being out there in a boat and encountering this group. That would in itself be something to show off about…

Atlantic Spotted Dolphins . Abaco Bahamas . @BMMRO
Atlantic Spotted Dolphins . Abaco Bahamas . BMMRO

All photos © Charlotte Dunn / Bahamas Marine Mammal Research Organisation (BMMRO). Please support the work of this specialist Bahamas marine mammal research team and help to preserve these increasingly vulnerable creatures LINK

SEAHORSES: PREHENSILE TALES FROM THE REEF


Seahorse (Adam Rees / Scuba Works)

SEAHORSES: PREHENSILE TALES FROM THE REEF

It’s a while since I showcased these astonishing little creatures. Adam Rees of SCUBA WORKS is a diver who combines great underwater experience with wonderful photographic skills. Here is a showcase for some of Adam’s seahorse photography and the amazing detail he captures. If these images don’t make you want to get your head underwater and explore the reefs, I can’t think what will…

Seahorse (Adam Rees / Scuba Works)Seahorse (Adam Rees / Scuba Works)

RANGE MAP by NAT GEO

Seahorse (Adam Rees / Scuba Works)Seahorse (Adam Rees / Scuba Works)

shlifecycle-e1313548153493

Seahorse (Adam Rees / Scuba Works)Seahorse (Adam Rees / Scuba Works)Seahorse (Adam Rees / Scuba Works)
Seahorse (Adam Rees / Scuba Works)

Seahorse by Alex Konahin

All fantastic photos: Adam Rees / Scuba Works; Range Map, Nat Geo; Lifecycle diagram, Seahorserun; Seahorse GIF, Alex Konahin

TUNICATES: SESSILE ASEXUAL SEA-SQUIRTS


Painted Tunicates Bahamas (Melinda Riger / GB Scuba)

TUNICATES: SESSILE ASEXUAL SEA-SQUIRTS

Painted Tunicates Clavina picta are one of several species of tunicate ‘sea-squirts’ found in Bahamas and Caribbean waters. These creatures with their translucent bodies are usually found clustered together, sometimes in very large groups. One reason for this is that they are ‘sessile’, unable to move from where they have taken root on the coral.

Painted Tunicates Bahamas (Melinda Riger / GB Scuba)

HOW DO THEY FEED?

Like most if not all sea squirts, tunicates are filter feeders. Their structure is simple, and enables them to draw water into their body cavity. In fact they have 2 openings, an ‘oral siphon’ to suck in water; and an exit called the ‘atrial siphon’. Tiny particles of food (e.g. plankton) are separated internally from the water by means of a tiny organ (‘branchial basket’) like a sieve. The water is then expelled. 

Diagram of adult solitary tunicate

Painted Tunicates Bahamas (Melinda Riger / GB Scuba)

WHAT DOES ‘TUNICATE’ MEAN?

The creatures have a flexible protective covering referred to as a ‘tunic’. ‘Coveringcates’ didn’t really work as a name, so the tunic aspect became the name. 

Painted Tunicates Bahamas (Melinda Riger / GB Scuba)

IF THEY CAN’T MOVE, HOW DO THEY… (erm…) REPRODUCE?

Tunicates are broadly speaking asexual. Once a colony has become attached to corals or sponges, they are able to ‘bud’, ie to produce clones to join the colony. These are like tiny tadpoles and their first task is to settle and attach themselves to something suitable – for life – using a sticky secretion. Apparently they do this head first, then in effect turn themselves upside down as they develop the internal bits and pieces they need for adult life. The colony grows because (*speculation alert*) the most obvious place for the ‘tadpoles’ to take root is presumably in the immediate area they were formed.

Painted Tunicates Bahamas (Melinda Riger / GB Scuba)

APART FROM BEING STATIONARY & ASEXUAL, ANY OTHER ATTRIBUTES?

Some types of tunicate contain particular chemicals that are related to those used to combat some forms of cancer and a number of viruses. So they have a potential use in medical treatments, in particular in helping to repair tissue damage.

Painted Tunicates Bahamas (Melinda Riger / GB Scuba)

Credits: all fabulous close-up shots by Melinda Riger / Grand Bahama Scuba; diagram from depts.washington.edu; magpie pickings with a particular mention of an article by Sara MacSorley

Painted Tunicates Bahamas (Melinda Riger / GB Scuba)

TOPICAL FISHES: WHOLLY ANGELS


The images below show the three species of angelfish commonly found among the coral reefs of the Bahamas. These were photographed by diver Melinda Riger in the waters round Grand Bahama. The Queen, French and Gray Angels are shown in both adult and juvenile forms.

Queen Angelfish
Queen Angelfish (juv.)
French Angelfish
French Angelfish (juv.)
Gray Angelfish
Gray Angelfish (juv. to adult phase)

All photos: Melinda Riger / Grand Bahama Scuba

CHRISTMAS TREE WORMS: SEASONAL SPIROBRANCHES


Christmas Tree Worm (Melinda Riger / Grand Bahama Scuba)

CHRISTMAS TREE WORMS: SEASONAL SPIROBRANCHES

music-notes-clip-art-png-musicDeck the Reefs with Worms Like Christmas Trees… Fal-La-La-etc-etc ” is a traditional Carol familiar to all. Well, most. Ok, some, then. Oh right – maybe with different words? Anyway, now is the perfect time to take a look at these remarkable subsurface symbols of seasonal good cheer (nb they are wonderful animals not gorgeous plants).

christmas-tree-worm-melinda-riger-g-b-scuba

10 CHRISTMAS TREE WORM FACTS TO PONDER

  • The 2 colourful spirals are not the worm, but complex structures for feeding & respiration
  • The spirals act as specialised mouth extensions for ‘filter-feeding’
  • Prey is trapped by the feathery tentacles & guided by cilia (microscopic hairs) to the mouth
  • The tentacle things are radioles and act as gills for breathing as well as prey traps
  • It is not believed that prey slide down the spiral to their doom, like on a helter-skelter

Christmas Tree Worm (Neil Hobgood Wiki)Christmas Tree Worm (Melinda Riger / Grand Bahama Scuba)

  • The actual worm lives in a sort of segmented tube, with extremely limited mobility skills
  • It contains digestive, circulatory & nervous systems – and a brain in the middle of it all
  • The worm also has a tiny drainage tube (I think I have this right) for excretion etc
  • They embed themselves into heads of coral such as brain coral. And stay there
  • And yes, the Christmas trees are retractable… (see below for some action)

spirobranchus_giganteus_orange_christmas_tree_worm-nick-hobgood-wiki

HOW DO THE WORMS… YOU KNOW…  ERM… REPRODUCE?

This is a delicate area. They are very discreet, but as far as I can make out they eject gametes from their what-I-said-above. There are mummy and daddy worms, and their respective gametes (eggs and spermatozoa) drift in the current and into each other to complete the union. The fertilised eggs develop into larvae, which settle onto coral and burrow into it as their parents did, build their protective tubes, and the process begins again.

christmas_tree_worm-nick-hobgood-wiki

YOU DON’T REALLY UNDERSTAND THESE CREATURES, DO YOU?

I won’t lie. I found it hard to work out how the CTWs function in practice. There are plenty of resources showing them in their full glory, but that only takes one so far. Then I came across a short video that shows it all brilliantly simply (except for the reproduction part).

The worms, in their coral burrows, hoist their pairs of ‘trees’. You can easily see small particles – zooplankton – drifting in the water, and the radioles swaying to catch potential food. Suddenly it all makes sense (except the repro bit – I haven’t found footage of that).  Next: the New Year Worm (there is no Easter worm).

A WHOLE FESTIVAL OF CHRISTMAS TREE WORMSChristmas Tree Worms (Neil Hobgood Wiki)

Credits: Melinda Riger (Grand Bahama Scuba); Nick Hobgood; Betty Wills; Video by ‘Super Sea Monkey’; Reef Collage by RH; MarineBio; Wikibits & Magpie Pickings

Happy Christmas to all those who put up with RH with such fortitude over the years
blue_christmas_tree_worm-betty-wills-wiki

INTERNATIONAL MANATEE DAY: BAHAMAS? WE GOTTEM!


West Indian Manatee, Bahamas (BMMRO / Charlotte Dunn / Keith Salvesen)

INTERNATIONAL MANATEE DAY: BAHAMAS? WE GOTTEM!

Manatees are apex ‘gorgeous marine mammals’. Gentle, inquisitive, brave, long-distance-but-rather-slow-swimming, grass-grazing miracle ur-elephant descendants. They never made it out of the sea in the Miocene epoch.

West Indian Manatee, Bahamas (BMMRO / Charlotte Dunn / Keith Salvesen)

Incongruous in a world of fast sharks, huge whales and leaping dolphins, they contentedly mooch around the seagrass beds. No one in the world has ever objected to or dissed a manatee. They bring only delight to the sea-world, and offer only charm to mankind.

West Indian Manatee, Bahamas (BMMRO / Charlotte Dunn / Keith Salvesen)

I’ve written quite often about the small number of manatees that inhabit the turquoise inner waters of the Bahamas. Almost all are named and some are tracked (until they lose their trackers). Their friendships and amorous hook-ups are recorded. Despite their relative scarcity in the Bahamas and a 16-month birth cycle, they produce manatee-lets and the family trees are very gradually growing.

West Indian Manatee, Bahamas (BMMRO / Charlotte Dunn / Keith Salvesen)

Gina and Calf, Bahamas (BMMRO)

IS THERE A DOWNSIDE FOR THESE APPARENTLY BLISSFUL AND PEACEFUL CREATURES?

Yes indeed. It’s mankind. Among the threats to the survival of these unusual, endearing, and legally protected creatures are, in no particular order:

  • Pollution of inshore waters and canals
  • Degradation of the (formerly limitless) sea-grass beds where they feed
  • Reduction or tainting of the fresh water sources that they need to survive
  • Understandable over-enthusiasm by admirers – especially in harbours – in dousing them with water from hoses and feeding them lettuce…
  • …and similar behaviours that may lead to a trusting dependance on humans
  • Unthinking or speed-selfish boat behaviour in or near harbours resulting in collisions
  • Simply not caring at all and carving them up, leaving often deep prop-scars. Few manatees escape at least a few of these. Some may not survive.

West Indian Manatee, Bahamas (BMMRO / Charlotte Dunn / Keith Salvesen)

Let’s celebrate this special day for manatees. Let’s hope that they can survive and prosper in these increasingly difficult and dangerous times for almost all species. Look at any of these photos… can we agree that these wonderful animals deserve care and protection.

All photos: Charlotte Dunn / BMMRO and research contributors

West Indian Manatee, Bahamas (BMMRO / Charlotte Dunn / Keith Salvesen)

SHARK ATTACKS – ABACO, BAHAMAS, & BEYOND


Shark! Melinda Riger, Grand Bahama Scuba

SHARK ATTACKS – ABACO, BAHAMAS & BEYOND

Over the last couple of weeks or so I have been getting a lot of hits for Shark Attack information. There have been 2 or 3 recent incidents including a tragic (and very rare) death in Maine, which may well account for this. The Shark Attack details I have accumulated and posted over the years are buried in an historical sub-sub-page, so to make things easier I have rechecked and updated the latest data resources and their links, and put them in a mainstream post. This is it.

DATABASE UPDATE 2020

INTERNATIONAL SHARK ATTACK FILE

PRIMARY RESOURCE

This resource is the portal to a mass of current, recent, and historical data, presented with authority and clarity. It provides undoubtedly the most comprehensive and accessible global shark-incident data of all.

Last year I included informative screen-shots taken from this site. For now I am confining the information to the most useful direct links. More work for the reader, perhaps, but also a better chance to explore and understand the hows, whens and wherefores of shark-related incidents – and how best to avoid the situation in the first place.

SITE LINK

https://www.floridamuseum.ufl.edu/shark-attacks/

BAHAMAS-SPECIFIC

https://www.floridamuseum.ufl.edu/shark-attacks/maps/na/bahamas-antilles/

The 2019 worldwide total of 64 confirmed unprovoked cases were lower than the most recent five-year (2014-2018) average of 82 incidents annually. There were five fatal attacks this year, two of which were confirmed to be unprovoked. This number is in line with the annual global average of four fatalities per year

MENU SELECTION

 Maps & Data    Contributing Factors    Shark Attack Trends 

What are the Odds?   Reducing Your Risk

For anyone thinking of entering waters where sharks live – eg scuba divers, spear-fishers, swimmers, boaters – with relatively little experience or knowledge, these links will be incredibly useful. Local knowledge is well worth having as well. A young friend of ours, an intern on Abaco, was warned against spearfishing at a particular location: “Fish there, you’ll get ate”. He did. He very nearly was.

“Humans are not on the menu of sharks. Sharks bite humans out of curiosity or to defend themselves”

The SRI produces a  downloadable Global Shark Attack File that provides:

  • A downloadable incident log by country
  • A downloadable incident log chronologically
  • A world map of encounters categorized by provoked vs. unprovoked, incidents involving boats, air & sea disasters and questionable incidents
  • To read any basic case report, open the Chronological file, click on the case number (column A) and the report will open as a pdf file

SHARK SPECIES (CONCISE OVERVIEW FOR EACH SHARK)

http://www.sharkattackfile.net/species.htm

BAHAMAS-SPECIFIC STATS

http://www.sharkattackdata.com/gsaf/place/bahamas

ABACO-SPECIFIC STATS

http://www.sharkattackdata.com/gsaf/place/bahamas/abaco_islands

Credits: All great shark photos – Melinda Riger / Grand Bahama Scuba; ‘Infest’ sticker design, Tracie Sugo

A FINAL THOUGHT

 

WORLD OCEANS DAY: WHAT YOUR DESCENDANTS MAY MISS


Bottlenose Dolphins Abaco, Bahamas (Charlotte Dunn / BMMRO)

WORLD OCEANS DAY: WHAT YOUR DESCENDANTS MAY MISS

Even the most optimistic lovers of unmolested wildlife, unpolluted oceans, un-degraded habitats, unextinguished species and understanding humans will be beginning to lose heart. Even as reports increase of resurgent wildlife during these Covid months, so it is gradually becoming clear that once humans are unlocked again, the only way will be down. 

Humpback whaleHumpback Whale, Abaco, Bahamas (Charlotte Dunn / BMMRO)

Here are just a few magnificent marine mammals to admire. All were photographed from the BMMRO research vessel in Abaco or adjacent waters. They are protected, recorded, researched, and watched over in their natural element – some individuals for more than a decade. 

Pantropical spotted dolphinsPan-tropical spotted dolphins, Abaco, Bahamas (Charlotte Dunn / BMMRO)

Today we contemplate our oceans at a time when the human species is having to confront a sudden and indiscriminate destructive force. Maybe the impact will lead to a recalibration of the ways we treat other species and their environment. We have contaminated the world’s oceans, perhaps irreparably, in a single generation. We could start by committing our support to those that tackle the plastic saturation, oil / chemical pollution, acoustic bombardment, ‘ghost gear’, and all the other unwelcome attritional activities we are responsible for. We could continue by supporting those that monitor and protect all the marine creatures struggling in a polluted environment that, in natural law, should be theirs.

Bottlenose DolphinsBottlenose Dolphins, Abaco, Bahamas (Charlotte Dunn / BMMRO)

Below is a male Blainville’s beaked whale, with its remarkable barnacled tusks that protrude upwards from its lower jaw. This is a specialist research species in the Bahamas. Below that is a short video of these whales that I took from the BMMRO research vessel. Turn up the volume – you will clearly hear them breathing as they slowly pass by (and others in the group, under) the boat. Note that land is clearly visible. These whales can sometimes be found just beyond the shallow turquoise waters, where the sea deepens as the depth drops down to an underwater canyon.

Blainville’s beaked whale (m)Blainville's Beaked Whale Abaco, Bahamas (Keith Salvesen / BMMRO)

Hope for the future…Sperm whale - neonate calf Abaco, Bahamas (Charlotte Dunn / BMMRO)

All photos taken in (or adjacent to) Abaco waters, Bahamas: Charlotte Dunn / Bahamas Marine Mammal Research Organisation (BMMRO), except for the beaked whale image and video by Keith Salvesen / Rolling Harbour (BMMRO)

Note: prognostications and personal views – and their intensity – detectable here are mine and do not necessarily reflect those of my colleagues at BMMRO… 

Farewell – but not goodbye, we must hope…Sperm Whale, Abaco, Bahamas (Charlotte Dunn / BMMRO)