‘DEEP DIVERS IN DIVERS DEEPS’: CUVIER’S BEAKED WHALES


Cuvier's Beaked Whale, Bahamas (BMMRO / Charlotte Dunn)

‘DEEP DIVERS IN DIVERS DEEPS’: CUVIER’S BEAKED WHALES

JOURNEY TO THE WORLD’S MIDNIGHT ZONE

Please join me in a dive down from the sparkling surface of the turquoise sea to the twilight zone at 200 meters. You’ll pass plenty of sea-life on the way: manatees grazing on seagrass just below the surface; reef fish, barracudas, reef sharks, mahi-mahi, maybe an orca at 100 meters. Other familiar creatures that are found even lower include a few reef fish, some shark species and green sea turtles. You are now running out of clear light.

Cuvier's Beaked Whale, Bahamas (BMMRO / Charlotte Dunn)

As you descend from 200 meters the waters become murky, then inky. The variety of inhabitants and their numbers are gradually decreasing. There are eels, some sharks, squid, stranger deep-water creatures. You may be surprised to see familiar bottlenose dolphins, recorded as diving nearly 300 meters. At 332 meters you will equal the deepest point any human being has ever scuba-dived (Ahmed Gabr 2014). There is little light, but you still have a long way to go to reach your goal.

Dolphin dive depth (Neal)

Descending still deeper, species and numbers continue to thin out. Around the world the limits of larger recognisable species is being reached – more shark species, tuna, chinook salmon, emperor penguins, swordfish, the few corals that can survive the depth. As the light fades to black, giant creatures and strange fish abound. Huge crabs. Sunfish. The (no-longer-extinct) Coelocanth. Massive octopuses. 

Cuvier's Beaked Whale, Bahamas (BMMRO / Charlotte Dunn)

Deeper down, nearing 1000 meters now, there are still some familiar species. Leatherback turtles; Baird’s beaked whales (nb not in the Atlantic); and at 920 meters, the deepest recorded sperm whale dive. It’s pitch dark: you have reached the level that sunlight never penetrates. You are in the Midnight Zone.

Sperm whale dive depth (Neal)

DEEP OCEAN DWELLERS

In black depths below 1000 meters, creatures have adpated to create their own light sources – so-called bioluminescence. This is the realm of the self-lit anglerfish, the blobfish and the goblin shark. It’s the Attenborough world of deep sea exploration. The geology is changing: there are hypervents, volcanic rocks, heavy metals. Below are the deep ocean-floor trenches. Yet there are still recognisable species down here, diving astonishingly deep to 1800 meters to feed – not least the narwhal which makes this trip several times a day to feed.

We need to quicken up the descent now – we have to get down nearly twice as far as this to reach our destination…

Cuvier's Beaked Whale leap (M.Rosso GIMA - IUCN)

We pass large squid and isopods, the deepest diving shark – the Greenland, the 10 meter-long 700 kilo colossal squid – yet amazingly there are marine mammals yet to be encountered: at 2400 meters we drift past a huge elephant seal. There are evil-looking creatures down here with names to match – devilfish, viperfish, black swallowers that can eat a larger fish whole, vampire squid and zombie worms. 

At 3000 feet, we finally end our quest. We have reached the depth to which the world’s deepest diving mammal has been recorded: the Cuvier’s beaked whale Ziphius cavirostris


Cuvier's Beaked Whale (NOAA Fisheries)

Cuvier’s beaked whales, or “goose-beaked whales,” are not rare. For a start, unlike many beaked whale species, they inhabit most oceans and seas in the world and have the most extensive range. Unsurprisingly therefore, they are one of the most often sighted beaked whale species and one of the best studied. 

Cuvier's Beaked Whale Bahamas (BMMRO / Charlotte Dunn)

FIN FACT

You may be wondering about the pressure exerted on a creature at a depth of 3000 meters. The answer is, an astounding 300 atm (atmospheres), enough to crush all but the hardiest and best adapted of species. The question how these whales manage to survive at such a depth is one for the future…

The Cuvier’s is one of the 3 beaked whale species found in Bahamas waters. Like the rarer Blainville’s and Gervais’s beaked whales, the Cuvier’s is the subject of ongoing research by the BAHAMAS MARINE MAMMAL RESEARCH ORGANISATION BMMRO

Cuvier's Beaked Whale leap (BW - Getty - Times)

The research into marine mammal populations in the Bahamas and far beyond is focussed on the massive increase in single and mass strandings, including recently in a remote area of Scotland (Hebrides) where more than 40 Cuvier’s were washed ashore.

One significant area of research examines the effect on marine mammals of man-made noise. There is plenty of it in the world’s oceans caused by noise pollution in and around shipping channels that traverse marine mammal migration, feeding and breeding grounds; naval surface and submarine exercises; seismic surveys, sonar waves and undersea resource investigations. The evidence of sound / acoustic damage as an additional hazard for marine mammals is starting to look very clear.

Cuvier's Beaked Whale Bahamas (BMMRO / Charlotte Dunn)

DEEP WATER INFOGRAPHIC

Do not miss this wonderful work by Neal Agarwal. This article is based around it and includes facts and images derived from his incredibly complex structure that has resulted in a remarkably simple resource for layman and ocean-lover alike (I realise these categories may overlap). To see the entire masterpiece, double click of the box below – “it will be worth it”.

CREDITS: Neal Agarwal; BMMRO / Charlotte Dunn; M.Rosso GIMA – IUCN; NOAA Fisheries; BW – Getty – Times; Pierangelo Pirak / BBC Earth (depth infographic), general sources – BMMRO, IUCN, NOAA, WDC

As ever, the Bahamas Philatelic Bureau has produced a wonderful stamp special issue

BAHAMAS MARINE MAMMAL RESEARCH: 20/20 VISIONS


Sperm Whale Calf, Abaco Bahamas (BMMRO)

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, Abaco Bahamas (BMMRO)

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, Bahamas (BMMRO)

Humpback Whale

ATLANTIC SPOTTED DOLPHINS

WEST INDIAN MANATEES – GINA and RANDY

West Indian Manatee, Bahamas - Gina (BMMRO)  West Indian Manatee, Bahamas - Randy (BMMRO)

All photographs and video footage: BMMRO

Sperm Whale tailing, Abaco Bahamas (BMMRO)

Sperm Whale Tailing, Bahamas

PILOT WHALES: “DIVIDED BY A COMMON SEA”


Pilot Whales, Abaco Bahamas (BMMRO / 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.

Pilot Whales, Abaco Bahamas (BMMRO / Rolling Harbour)

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?Pilot Whales, Abaco Bahamas (BMMRO / Rolling Harbour)

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.

Pilot Whales, Abaco Bahamas (BMMRO / Rolling Harbour)

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.

Pilot Whales - dorsal fin ID, Abaco Bahamas (BMMRO / Rolling Harbour)

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.

Pilot Whales, La Gomera, Canary Isles (Rolling Harbour / YN) Pilot Whales, La Gomera, Canary Isles (Rolling Harbour / YN) Pilot Whales, La Gomera, Canary Isles (Rolling Harbour / YN) Pilot Whales, La Gomera, Canary Isles (Rolling Harbour / YN) Pilot Whales, La Gomera, Canary Isles (Rolling Harbour / YN)

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

Pilot Whale (Marina Nolte / Wiki)

FOLLOWING DOLPHINS IN THE BAHAMAS…


Following Dolphins (SailorDolphin / BMMRO)

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.

Following Dolphins (SailorDolphin / BMMRO)

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. 

Following Dolphins (SailorDolphin / BMMRO)

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

Following Dolphins (SailorDolphin / BMMRO)

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


Atlantic Spotted Dolphins in Abaco Waters (BMMRO)

‘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. 

Atlantic Spotted Dolphins in Abaco Waters (BMMRO)

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…”

Atlantic Spotted Dolphins in Abaco Waters (BMMRO)

Just because it can…Atlantic Spotted Dolphin leaping in Abaco Waters (BMMRO)

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.]

Atlantic Spotted Dolphins in Abaco Waters - marine trash (BMMRO)

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.

Atlantic Spotted Dolphins in Abaco Waters - marine trash (BMMRO)

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