COOKIECUTTER SHARKS: BEASTLY LITTLE SUCKERS

January 19, 2022 by Rolling Harbour

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.

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.

** “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 heal

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

BAHAMAS DOLPHINS: VIEW FROM A RESEARCH BOAT with BMMRO

November 18, 2021 by Rolling Harbour

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

ATLANTIC SPOTTED DOLPHINS . ABACO BAHAMAS

March 2, 2021 by Rolling Harbour

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…

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

SPERM WHALE BONES & RESEARCH: LIFE AFTER DEATH

March 31, 2020 by Rolling Harbour

SPERM WHALE BONES & RESEARCH: LIFE AFTER DEATH

I made this short video last year at BMMRO HQ, Sandy Point, Abaco. A sperm whale had stranded earlier in the year, and after the necropsy some of the bones were taken from the beach for research. In order to clean them, the bones were sunk and anchored to the seabed offshore in quite shallow water. Strandings are always sad, of course, but it is good to know that even after death the creature makes an important contribution to scientific research. In a sense, it has life after death.

BMMRO / Rolling Harbour Abaco / Keith Salvesen

MANATEES: PICTURE PERFECT ON ABACO (4)

March 25, 2020 by Rolling Harbour

MANATEES: PICTURE PERECT ON ABACO (4)

MANATEE APPRECIATION DAY 2020

Mrs RH and I are sticking to self-isolation right now (we are fine, but thank you for asking). However I am already breaking my current self-imposed ‘single-picture-and-not-much-writing’ regime with today’s creature feature. The excuse? It is of course the last Wednesday in March and as everyone must know it is Manatee Appreciation Day.

Anyone can (and indeed should) appreciate manatees anywhere at any time, and their contemplation is a way to lift the spirits. They were first found in Abaco waters about a dozen years ago. BMMRO reported their movements and the ongoing research. Later, Bahamian locals enthusiastically followed the lives of Gina, Rita, Georgie, Randy & co; and the calves such as JJ and Sayle (winning name in a public competition). Citizen scientist reports were invaluable to the research. Unsurprisingly, since Hurricane Dorian reports have greatly reduced. Manatees may well still be around but even now, 6 months later, trichechi sightings are sporadic. There are other concerns, after all.

Manatees love the camera and, Madonna-like, are often pleased to ‘strike the pose’. Of a sort.

Today the Marine Conservation Society (MCS) showed their appreciation for manatees with a superb image and an excellent set of Manatee Facts that I recommend to anyone who has read this far. For example, recent broadcasts and news articles have featured the importance of seagrass. You will see that it is the primary diet of manatees.

View this post on Instagram

A post shared by Marine Conservation Society (@mcs_uk)

Credits: Photos #1 – #4 Charlotte Dunn / Bahamas Marine Mammal Research Organisation (BMMRO) and #5 Caine Delacy / BMMRO; MCS UK

MCS links: https://www.mcsuk.org; https://www.facebook.com/mcsuk/

Gina with her calf Sayle

DOLPHINS IN THE SEA OF ABACO, BAHAMAS

March 6, 2020 by Rolling Harbour

Dolphin mother and newborn calf

DOLPHINS IN THE SEA OF ABACO, BAHAMAS

The bottlenose dolphin photos here, taken during a recent BMMRO dolphin research project in the Sea of Abaco, are of great significance. Six months after Hurricane Dorian smashed the life out of Abaco, the island is still in the early stages of recovery – to the extent that recovery is possible when the main (only) town has been pulverised to rubble and the island’s infrastructure wrecked. Good news is prized.

Amidst the human cost of Dorian to the Abaco community, people have found some consolation in the natural world around them. The return of birdsong. The bright flashes of the unique parrots flying overhead. Shorebirds returning to the beaches from wherever they found for cover. Curly-tail lizards sunning themselves. And on water, sightings of turtles, rays and dolphins to spread some cheer. Some huge bonefish are being caught (and released) too.

The Bahamas Marine Mammal Research Organisation (BMMRO) has its HQ at Sandy Point. During the past months, life there has been busy. A long-term underwater acoustic research project is in progress, for example. The effects of the hurricane on the marine mammals in Abaco waters – whales , dolphins and manatees – has been a cause of great concern. A drop in the dolphin population in the Sea of Abaco had been noted a few months ago, so a second assessment of the area has just been carried out.

Playtime in the Sea of Abaco

GOOD NEWS FOR DOLPHINS

Scientists Diane Claridge and Charlotte Dunn obtained positive results. During the assessment, they encountered 18 individual dolphins. The encouraging observations included:

The wonderful mother and newborn calf in the header image – a great sign of hope
Some dolphins first recorded – amazingly – in 1992
Dolphins in areas not used for years, probably due to recent reduced boat traffic
Familiar dolphin behaviours such as wave-surfing and group socialising

Ragged dorsal fin patterns enable easy ID

If you wonder how researchers can be so sure about the ID of the animals they see, check out the dorsal fins in some images here. Individual dolphins have unique patterns, markings (#2) and in particular fin damage that is readily identifiable. Seen close to, these are obvious. At a longer distance, binoculars are needed. Photos of each animal are also taken to be analysed in the lab. Sound recordings may be taken: distinctive individual voice patterns are analysed to assist ID. All of this can be compared against the BMMRO database. That is how dolphins first recorded in 1992 can be identified with such certainty now.

Credits: Charlotte Dunn (photos) and Diane Claridge, BMMRO; the dolphins for research cooperation

If you would like to know more about the work of BMMRO and its research, click the logo above

BAHAMAS MARINE MAMMAL RESEARCH: 20/20 VISIONS

November 29, 2019 by Rolling Harbour

Neonate Sperm Whale Calf, Abaco Bahamas

BAHAMAS MARINE MAMMAL RESEARCH: 20/20 VISIONS

Change is in the air. And in the sea. Above, you will notice the brand new logo of the Bahamas Marine Mammal Research Organisation BMMRO based in Sandy point, Abaco. Several major Bahamas-wide projects are in progress or in preparation, and as we approach 2020, this is the perfect time for some marine mammal news, illustrated with great images from BMMRO research trips.

Bottlenose Dolphins

BMMRO’s scientific research over many years is a prime reason why we all have the privilege of seeing the neonate sperm whale calf in the header image. It was photographed with its mother off South Abaco last Spring. Much-appreciated support of the essential research and conservation work of the organisation helps to ensure that the whales, dolphins and manatees in Bahamas waters are watched over, documented in minute detail (even their calls) and protected. The marine mammals of the Bahamas have a promising future looking ahead to 2020, and well beyond.

Blainville's Beaked Whale, Abaco Bahamas (BMMRO)

Blainville’s Beaked Whale and young calf

Humpback Whale

ATLANTIC SPOTTED DOLPHINS

WEST INDIAN MANATEES – GINA and RANDY

All photographs and video footage: BMMRO

Sperm Whale tailing, Abaco Bahamas (BMMRO)

Sperm Whale Tailing, Bahamas

PILOT WHALES: “DIVIDED BY A COMMON SEA”

February 25, 2019 by Rolling Harbour

PILOT WHALES: “DIVIDED BY A COMMON SEA”

You know the thing about Britain and the US being ‘two Nations divided by a common language’? Among the many august people credited with first coming up with this remark, the leading contenders are Oscar Wilde, George Bernard Shaw and Winston Churchill. Generally, Wilde seems to be considered the winning author**. Whichever, the saying is intended to be lightly and amusingly rude, probably to both nations.

Well, pilot whales are in a similar position. They are found on both sides of the Atlantic (and many other places of course). As acoustic analysis of the sounds made by marine mammals becomes increasingly sophisticated, the evidence suggests that a pilot whale in The Canary Islands saying “Hey guys, meal approaching 11.00 o’clock, moving right, 30 feet” will use different sounds from its counterpart in the Bahamas.

A pilot whale with a recent injury to its jaw. Chief suspect: a COOKIECUTTER SHARK?

Short-finned pilot whales (Globicephala macrorynchus) are also known as blackfish or potheads (though some may reserve this last term for – ahem – higher species). As with MELON-HEADED WHALES, they are in fact a species of large dolphin. They can grow to nearly 20′ long and weigh accordingly.

Pilot whales live in large pods of 50 or more. These are so-called ‘matrilineal’ groups, meaning that they consist of 2 or even 3 generations of related females. When the sea is calm, they sometimes adopt a behaviour known as ‘logging’, in which they will spend a long time – maybe hours – lying on the surface in tight groups.

In The Bahamas, pilot whales are seen year-round but are more common during the spring and summer months. Some are resident, but Bahama pilot whales appear to have large ranging patterns. Pilot whales tagged in The Bahamas have travelled as far north as North Carolina suggesting they are part of a population located in the US southeast .

HOW DO RESEARCHERS RECOGNISE EACH ANIMAL?

The first place to look is the dorsal fin. There are (at least) two reasons for this. First, it’s the part of the dolphin / whale that is most visible through binoculars; secondly, it is the part that tends to acquire nicks, ragged edges, and scar patterns that are unique to that animal. When a new cetacean is sighted, it is logged and assigned an ID. This will usually be kept simple and scientific: “look, there’s AL16 again” and so on; how unlike birds, where banders assign names such as Felicia Fancybottom, Bahama Mama and Harry Potter.

If you look at #2 above, notice the distinctive hooked dorsal fin of the right-hand pilot of the trio. An easy ID for future sightings. And see below for nicks and scarring.

MEANWHILE, 3643 MILES EAST ACROSS THE ATLANTIC

Last Autumn my niece and her family went to La Gomera, a small volcanic island in the Canaries. They all went on a whale / dolphin watching trip and were delighted to encounter a group of pilot whales. My great nephew, not yet a teenager, had an iphone with him and in the circumstances of standing on a moving platform photographing creatures swimming fast through the water, he did a very good job. A couple of them even have a bonus shearwater.

The west and east Atlantic pilot whales shown here are almost exactly on the same latitude

I’m not particularly bothered by my lack of photographic eptitude, but even I feel that my own shot of a pilot whale in the Sea of Abaco rates high in the list of epic fails

The identity of the photographer is protected under the Official Secrets Act 1989

** ‘We have really everything in common with America nowadays except, of course, language’ Oscar Wilde The Canterville Ghost (1887)

Photo Credits: 1 – 5, BMMRO / Rolling Harbour; 6 – 10, my naturalist nephew Yarin; 11, name withheld by order of the management; 12, Marina Nolte / Wiki. General thanks: Diane, Charlotte, BMMRO

FOLLOWING DOLPHINS IN THE BAHAMAS…

October 22, 2018 by Rolling Harbour

FOLLOWING DOLPHINS IN THE BAHAMAS…

The Bahamas Marine Mammal Research Organisation (BMMRO) is based at Sandy Point, Abaco. The principals Diane Claridge and Charlotte Dunn with their team cover not only Abaco waters but the whole of the Bahamas. Their research work is complex, and some of it is carried out in conjunction with partners on specific projects or more generally.

Which brings me to SailorDolphin Research, a project that involves the meticulous mapping, photographing, and recording of the details of each sighting. Much of the work is carried out in the Bahamas in partnership with BMMRO. The link will take you to the homepage, which notes “This website provides a list of Dolphins that I have documented on the US East coast and the Bahamas. It includes details (with photos & notes) for each dolphin and lists of their sightings from my personal database.” If you have an interest in dolphins (and who does not?), it will repay exploration – and you will see some awesome photographs. Here are a few of them to admire.

Now imagine yourself in the water, with these wonderful creatures cutting through the water in front of you, working their sleek bodies just below the surface, jostling and cavorting, occasionally letting a fin cut through the water. Hold that thought… Right, get back to work!

All photos courtesy of SailorDolphin / BMMRO

SPERM WHALES TAILING: ABACO, BAHAMAS

August 9, 2018 by Rolling Harbour

SPERM WHALES TAILING: ABACO, BAHAMAS

There can be very few people in the world whose breath would not be taken away by the sight of a massive sperm whale tailing close by. And as it happens, this very phenomenon can be seen in the deeper waters around the coast of Abaco. Here is a small gallery of photos of sperm whales tailing, taken from the BMMRO research vessel. There’s no point in my writing a lot of commentary to the images – they speak for themselves of the awesome (in its correct sense) power and grace of these huge mammals.

In these images, you will notice that the whales have distinctive patterns of notches and tears in their flukes (ie tail fins). As with a dolphin’s dorsal fin, these areas of damage are like fingerprints – unique to each individual, and a sure means to identification. The researchers log each sighting and assign a cypher – a whale will become known as ‘B42’ and not usually by a less scientific name like ‘Derek’ or ‘Susie’).

Q. What happened next? A. You would see the tail emerge as the whale dives deep…

One of my favourite whale views is of the tail as it rises above the surface with water streaming off the flukes, before it flicks over and disappears beneath the waves.

A juvenile takes a dive alongside an adult. One day that tail will be massive… Sperm Whale Tailing, Abaco, Bahamas (©BMMRO)

Credits: all photos © BMMRO, with thanks as ever to Diane and Charlotte

‘WELL SPOTTED’ (2): ATLANTIC SPOTTED DOLPHINS IN ABACO

July 13, 2018 by Rolling Harbour

‘WELL SPOTTED’ (2): ATLANTIC SPOTTED DOLPHINS IN ABACO

No sooner have I posted about PANTROPICAL SPOTTED DOLPHINS sighted during the current BMMRO whale research program, than the other Bahamas spotted dolphin species shows up as well. These are the more numerous Atlantic Spotteds Stenella frontalis, more confined in range (as the names suggest) than the Pantropicals.

The BMMRO caption reads “Atlantic spotted dolphins today! Small social group playing with sargassum – they swam past what looked like a plastic mattress cover – one dolphin whacked it with its tail as it swam by…”

Just because it can…

RUBBISHING RUBBISH: A RANT

Behold a large plastic bag, made by humans and dumped by humans into a place that is not theirs to use as a trash repository. It will take some 500 years to break down completely. But when people say that they don’t really mean it will have harmlessly disappeared over that period and become salt water. Far rom it. It will just break down into smaller and smaller pieces, to bite-sized bits for turtle, fish and seabirds who will idiotically mistake them for food (duh!), then to micro-plastic that will become part of the evolving plastic soup that will be ingested by tiny sea creatures and coat the reefs in polyethylene gunk. [End of rant. Ed.]

Behold an Atlantic Spotted Dolphin giving the bag a passing whack with its tail. It won’t do anything to help with marine pollution, but is shows a robust disdain for a piece of man-made rubbish that has made it into the creature’s home environment.

Below is a short GoPro shoot of a pair of ASDs, that I took from the BMMRO research boat last year. Marvel at the grace and elegance of these beautiful animals as they swim just below the surface (wonder, too, at the incompetence of the cameraperson who, to be fair, was leaning over the side of the RHIB with the camera on a stick…)

All photos BMMRO; video from the Rolling Harbour achives, intemperate rant all my own

MARINE POSTER COMPETITION FOR ABACO KIDS

June 29, 2018 by Rolling Harbour

MARINE POSTER COMPETITION FOR ABACO KIDS

BMMRO recently collaborated with Dolphin Encounters Marine Education Poster Contest in a competition for schoolchildren on Abaco. There were 3 age groups, 3 -5, 6 – 8, and 9 – 12. The young participants received the excellent BMMRO marine educational poster as a prize, though I suspect they were motivated not so much by a prize but by the fun possibilities of the challenges set for them.

And how well they met them. I am featuring a selection of the prizewinners as posted by BMMRO on FB and Insta. Bearing in mind the ages of the artists, the results are astounding. As someone for whom the task of drawing a stickman presents insurmountable difficulties of perspective, proportion, form and accuracy, I am in awe of the inventiveness of these young minds and their artistic skills. They’ve done a fantastic job in highlighting the critical conservation issues facing all marine creatures large and small, with an awareness that I hope will help stay with them into adulthood.

Do I have a favourite, I asked myself. Actually, no – I’d just be proud to have any of these on my wall. And I bet the teachers and the families involved all feel the same.

HUGE CONGRATULATIONS TO ALL THE WORTHY WINNERS

BMMRO children's poster competition winners

SPERM WHALES GATHERING IN ABACO WATERS

June 26, 2018 by Rolling Harbour

SPERM WHALES GATHERING IN ABACO WATERS

During the past week, the BMMRO research boat has been tracking sperm whales off the south coast of Abaco. These huge creatures are the largest marine mammals found in Bahamian waters, and the area between Rocky Point around the south coast to Hole-in-the Wall is a great place to find them.

One reason they are found in this particular area is the existence of the Great Bahama Canyon, one of the deepest submarine canyons in the world. The depth of the canyon ensures that the waters are nutrient-rich, with food being drawn up from the depths towards the surface. In season it’s the perfect place for female sperm whales and their calves.

The BMMRO research trip encountered more than a dozen sperm whales, mostly females with their calves. And the amazing thing is that the sightings are often made within sight of land. In these photos, the are two landmarks visible. One is the huge Disney vessel parked at Gorda Cay aka Castaway Cay (header image); the other is HOLE-IN-THE-WALL LIGHTHOUSE (above)

Credits: All photos BMMRO 2018, with thanks to Diane & Charlotte as ever

‘SOCIABLE DOLPHINS’: MELON-HEADED WHALES

May 22, 2018 by Rolling Harbour

‘SOCIABLE DOLPHINS’: MELON-HEADED WHALES

Last month, BMMRO undertook a joint expedition with FIELD SCHOOL to carry out research on sperm whales. This took them out into deep water, where another, quite different, cetacean species was also encountered on the final day – a huge pod of more than 100 melon-headed whales Peponocephala electra.

The melon-headed whale is in fact – like the FALSE KILLER WHALE I recently wrote about – a species of dolphin. It is sometimes more accurately called the melon-headed dolphin, which removes any confusion. These creatures are oceanic, preferring deeper waters. For that reason they are not often encountered, despite being quite common in tropical and sub-tropical waters around the world.

The MHW belongs to a dolphin species commonly known as blackfish. Other dolphins in this group included, for the Bahamas, the pygmy killer whale and the more frequently encountered pilot whale, a species than can be seen in the Sea of Abaco.

In some of these photos you can see the distinctive white lips of the MHW

Melon-headed whales are notably social animals. They live in large groups – often more than 100-strong (as the expedition found), up to as many as 1000 individuals. Within these large groups, smaller groups of a dozen or so form and stay close as they swim.

Note the ‘Rainbow Blow’ caught in this photo Melon-headed whales, Bahamas (BMMRO / Field School)

MHWs appear to communicate or perhaps to bond by touching flippers. MHWs also associate with other dolphin species, and they have even been recorded with large whales such as humpbacks.

Other observed behaviour includes sub-surface resting in numbers, boat-wave riding, and so-called ‘spy hopping’ (above). This last activity may be carried out by several resting animals, which jump vertically out of the water and splash back again into the ocean (see also the Header image).

This video was recorded during the expedition. You’ll get a very good idea of the size of the group from the drone shots as they pull out. I doubt that many people would expect to see such large sea creatures in such numbers – it must be an awesome** sight.

10 MELON-HEADED FACTS WITH WHICH TO ASTOUND YOUR LOVED ONES

The MHW’s head is rounded, lacking the obvious beak of more familiar dolphins
The darker grey face is sometimes called a ‘mask’
Their distinctive white lips are a good identifying feature
They are capable of swimming at very fast speeds
Like other dolphins, they make series of low jumps out of the water as they swim
Their groups often contain 100 individuals, up to as many as 1000
An adult grows to around 3m / 10′ long
They live for at least 20 years, and females may live as long as 30 years
As with many certaceans, their favourite food is squid
Oh, did I mention that they are really dolphins and not whales at all?

CREDITS: all fantastic photos & the original of the video clip – © BMMRO / Field School

** In its true and original meaning of ‘inspiring wonder and awe’ (historically, in a religious sense), rather than the diluted modern usage as in ‘awesome pizza’ or ‘awesome selfie’

THE ARTICULATE WHALE (2): MARINE SCIENCE ON DISPLAY

April 19, 2018 by Rolling Harbour

THE ARTICULATE WHALE (2): MARINE SCIENCE ON DISPLAY

A couple of months back I wrote about the fate of the false killer whale Pseudorca crassidens (in fact a species of dolphin) that was stranded on Duck Cay. After its discovery, it was cut up, buried for many months before being disinterred, cleaned… and made ready to be reconstructed for display at Friends of the Environment, Marsh Harbour for research and educational purposes. The poor dead creature was destined to have a future ‘life’ (in a sense) as an exhibit. You can read the details and see the various stages of the preparatory processes (including some gory images) HERE.

The FKW joint project (see below for participants) has taken more than a year. The final stage has been similar to doing a jigsaw puzzle, with the added complication that it isn’t entirely clear where or even whether all the pieces fit – there may even be one or two leftover small bones when the reconstruction is finished.

HEAD False Killer Whale Skeleton, Abaco Bahamas (Keith Salvesen / BMMRO)

Since I last wrote about the ‘rearticulation’ project, I have spent some time on Abaco. A highlight was our visit to FotE to meet the jocundly-named ‘Ducky’ of Duck Cay [I’d have gone for ‘Killer’ as a name – there’s no such thing as bad publicity]. Incidentally the strange item on the whale’s skull is in fact nothing to do with the creature’s real structure – it’s a natural historian’s unicorn-related jest…

RIBCAGE & SPINE False Killer Whale Skeleton, Abaco Bahamas (Keith Salvesen / BMMRO)

Besides identifying all the bones and numbering them, those working on this project have had to devise ingenious methods for display to make the reconstruction as accurate as possible – not an easy task with a creature nearly 20 feet long.

SPINE

FLIPPER 1 – COMPLETE

FLIPPER 2 – WORK IN PROGRESS

JAW & A TRAY OF SUNDRIES…

It would be against the principles of this blog to miss out on an obvious open goal of an opportunity for an apposite final caption…

A WHALE TALE THAT ENDS WITH THE WHALE TAIL

This ambitious year-long project has involved BMMRO, FOTE, BEP (Bahamas Environment Protection Foundation), interns, and volunteers. A number of children from local schools have already been to visit Ducky and been completely fascinated. A dead stranded whale now has a new incarnation, and a new story to tell.

ARE STRANDINGS FREQUENT – AND WHY REPORT THEM?

Each year there may be half-a-dozen reports of cetacean strandings in Abaco waters, both whales and dolphins. As far as I can make out, the animals are almost invariably dead. If still alive, reporting is clearly urgent to ensure a quick response and to maximise the creature’s chances of survival. If dead, a carcass can provide scientists with valuable data on the biology and health of marine mammals and, in turn, the health of our marine ecosystems. This includes basic information, such as an animal’s age, its size, the types of prey it consumes, and the occurrence of diseases. Necropsies can provide more detailed information to add to the growing knowledge-base of marine mammal populations.

And a project like this one, with its great educational potential, can in effect enable a stranded marine mammal to tell its story even after death.

STRANDING NETWORK HOTLINE NUMBER +1 242 366 4155

(or +1 242 357 6666 / +1 242 577 0655)

Credits: all photos by Keith Salvesen / BMMRO. Special thanks to Olivia Patterson and all at Friends of the Environment for a fascinating time visiting ~~Ducky~~ Killer; and to Nancy Albury for showing us around the excellent Museum. If you haven’t been, go!

THE PRINCE OF WHALES: BLAINVILLE’S BEAKED WHALES IN ABACO

April 5, 2018 by Rolling Harbour

THE PRINCE OF WHALES: BLAINVILLE’S BEAKED WHALES IN ABACO

There’s a strange affinity between humans and whales. Humans seem to think so, anyway – and whales seem to tolerate them amiably, perhaps now that the decimation of their populations by humans is (largely) a thing of the past. The Bahamas in general and Abaco in particular are in the mainstream of progressive cetacean research, led by the BMMRO at Sandy Point.

One of the speciality research species is the Blainville’s Beaked Whale. These magnificent creatures are deep divers, and although they are found in many parts of the world, the Bahamas is one of only 3 locations with a significant population for study. Most of the whales here were photographed within sight of land (and a few with the Castaway Island Disney Cruise Ship visible on the horizon!).

I’ve been lucky enough to be on the BMMRO research vessel on a beaked whale outing – and luckier still that we were able to spend plenty of time with a group of them, including some males. The header image is of a mature male with his huge teeth that protrude upwards from the lower jaw, and in time become encrusted with barnacles.

The whales were quite undisturbed by our presence – indeed they behaved much like dolphins, circling the boat and swimming under it; moving away and returning. This was an opportunity to count the whales, to identify those that had already been recorded, and to document any new ones. Each whale has its own unique pattern of marks, striations and in some cases healed wounds. The pair below are a good example.

Also, the whales have individually distinctive dorsal fins, with nicks and tears that also act as a means of identification. These can often be made out from a distance with powerful binoculars or photographed with a long lens for later analysis (this ID method also works reliably for dolphins).

Beaked whales often bear the healed scars from the gouging bites of COOKIE-CUTTER SHARKS, a vicious little species that I recently featured. The distinctive circular scars on the back of the whale below result from encounters with these unpleasant creatures.

Finally, the photo below. It has no merit, photographically speaking, but I love the way that sometimes a ‘risk’ shot – into the sun, perhaps – produces rather magical effects. The unexpected ‘sea stars’ were a bonus!

All photos: Keith Salvesen / BMMRO

THE ARTICULATE WHALE (1): TELLING A TALE AFTER DEATH

February 26, 2018 by Rolling Harbour

THE ARTICULATE WHALE (1): TELLING A TALE AFTER DEATH

The ‘false killer whale’ Pseudorca crassidens has a somewhat misleading name: first (as implied), it is not a killer whale; second, it’s not actually a whale at all, but a large species of dolphin. However, it does have some killer whale tendencies – attacking and killing smaller marine mammals for example – and perhaps a passing resemblance, so the species has been given something of an upgrade, name-wise.

Although these fine creatures are distributed widely around the globe, the overall numbers are thought to be small, and relatively little is known about them in the wild. They are, of course, used as aquarium exhibits but the knowledge gleaned in captivity cannot provide much of an overview of their oceanic behaviour, which remains relatively unstudied.

However, there is one source of valuable data – the scientific study of stranded animals. And as it happens, Abaconians will very soon be able to obtain at least a skeleton knowledge of the FKW, the end-product of a long and complicated research project by the BMMRO in conjunction with Friends of the Environment. Just a quick word of warning before you read further – some images below are not especially pleasant to look at, so be prepared for them… They are illustrative and not intended for close inspection (unless you want).

Exactly a year ago an FKW was reported to have stranded on Duck Cay, off Cherokee Sound. BMMRO were quickly on the scene, and hoping to undertake the usual procedure of a necropsy, in which post-mortem samples are taken for analysis. However the poor creature was in an advancing state of decomposition, so only skin samples and photographs could be taken.

Telescoping the intervening months for the sake of brevity, the decision was made to cut up the carcass (note the face-masks) and bury it where it was, so that its integrity would be preserved for later retrieval, cleaning, reconstruction (‘re-articulation’) and exhibition for educational purposes.

In December, the remains were exhumed for the next phase of the animal’s decomposition – submersion in cages in the mangroves – before the final cleaning of the bones in readiness for its re-articulation and display.

Cleaning the bones has been a meticulous process, leaving the resulting skeleton ready to reconstruct in situ at Friends of the Environment’s Kenyon Research Centre in Marsh Harbour. Adult FKWs can grow up to 6 metres long, so there are a great many bones from large to very small to place correctly – and plenty of teeth (see below). The re-articulation is nearly finished, and it is hoped that the completed skeleton will be on display in the very near future. I am planning to see it in about 2 weeks time, and – this sounds quite strange, I know – I’m very excited about it.

This ambitious year-long project has involved BMMRO, FOTE, BEP (Bahamas Environment Protection Foundation), interns, and volunteers. I am keen to know whether, in the modern way, an affectionate name has been chosen for the skeleton. ‘Duck Cay’ doesn’t provide a very promising start. Well, maybe Donald is in vogue…?

ARE STRANDINGS FREQUENT – AND WHY REPORT THEM?

And a project like this one, with its great educational potential, can in effect enable a stranded marine mammal to tell its story even after death.

STRANDING NETWORK HOTLINE NUMBER +1 242 366 4155

(or +1 242 357 6666 / +1 242 577 0655)

False Killer Whale skull, Abaco Bahamas (BMMRO)

Credits: header image, Endless Ocean / wiki; #1 NOAA; all other photos BMMRO or FOTE, with thanks; range map wiki

COOKIECUTTER SHARKS: BEASTLY LITTLE SUCKERS

February 5, 2018 by Rolling Harbour

COOKIECUTTER SHARKS

BEASTLY LITTLE SUCKERS

HOW COME THE NAME?

These sharky little b@st@rds (*technical term*) attack marine mammals and fishes, 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

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

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?

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 (e.g. 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’: they ‘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

Cookiecutter Shark – the real deal

MONSTERS OF THE DEEP

Alright now…

PS Apologies to anyone who bothered to wade through this, and stayed awake long enough to notice that formatting gremlins struck halfway through

SPERM WHALES – BMMRO FIELD TRIP, BAHAMAS

November 28, 2017 by Rolling Harbour

SPERM WHALES – BMMRO FIELD TRIP, BAHAMAS

I can never quite get my head around the fact that the waters around Abaco are home to the twin leviathans, sperm whales and humpback whales. And before anyone points it out, I realise they can’t actually be twins: sperms whales (cachelots) are TOOTHED WHALES whereas humpback whales are BALEEN WHALES.

During November, the Bahamas Marine Mammal Research Organisation (BMMRO) undertook a rather special field trip. Using sophisticated devices, the scientists first located a group of sperm whales, and then tracked them through the night using the communications between the creatures – ‘vocalisations’ – to follow them. Later analysis of the recordings will have made it possible to identify the individuals through their unique vocal patterns – and so to recognise them again.

The hydrophonic equipment used is extremely sensitive, and can pick up the sounds made by whales and dolphins over a great distance. The box of tricks looks deceptively modest – I took these photos on a previous trip when we were looking for beaked whales and dolphins. Charlotte Dunn holds the microphone submerged on a cable and underwater sounds are amplified so that the slightest chirrup of a dolphin can be heard by everyone on the vessel. The sounds are recorded and locations carefully logged.

Besides the sperm whales, the BMMRO team also had sightings of spotted dolphins, bottlenose dolphins and beaked whales during the field trip. These bonus sightings will also have been logged for future reference. It all adds to the detailed research data that assists the conservation of the prolific marine mammal life in Bahamian waters.

Atlantic Spotted Dolphins Atlantic Spotted Dolphins, Bahamas (BMMRO)

By the time one of the whales decided to breach, it was some distance away, so I’m afraid I can’t bring you a dramatic close-up from the trip. But just to see this view at all is breathtaking.

All photos BMMRO except the 2 hydrophone ones on the research boat (Keith Salvesen)

BLAINVILLE’S BEAKED WHALES IN ABACO WATERS

October 16, 2017 by Rolling Harbour

BLAINVILLE’S BEAKED WHALES IN ABACO WATERS

It’s hard to believe that the seas around Abaco and its cays are home to a number of whale species, from huge sperm and humpback whales down to so-called dwarf or pygmy species. In the middle of this range come the beaked whales, the most common being the Blainville’s Beaked Whale. I say ‘most common’, but in fact they are rare in the world, being found in only two other main locations on earth.

These whales are carefully monitored by the Bahamas Marine Mammal Research Organisation (BMMRO), and there is a tagging program to keep track of them. As with dolphins, individuals are identified by markings on the dorsal fin, which vary for each whale. The one above has distinctive scarring at the tip. There are also striations on the body, and conspicuous circular marks that are healed wounds caused by cookie-cutter sharks.

To the untrained eye, there are no noticeable marks on the dorsal fin of the whale above. However, the whale’s back has a prominent pattern of scarring and healed cookie-cutter wounds. The whale below really looks as though it has been in the wars, with long deep healed wounds behind the head.

I can’t tell without seeing the head, but I wonder if it is a male and the scars have been caused in a fight with another male – adult males have prominent tusks with which they do battle. Here is an photo that I took from the research boat on a different occasion. The tusks protrude upwards from the lower jaw, and are often covered in barnacles. They are capable of causing serious injury.

Blainville’s beaked whales are amongst the deepest divers of all whales. But that and other whale topics will have to wait for another day… My computer malware / virus has been removed professionally with no data loss, and I have some catching up to do. Cost in terms of panic and stress: huge. Cost in real terms: $90.