BAHAMAS REEF FISH (39): YELLOWTAIL DAMSELFISH


Yellowtail Damselfish (©Melinda Riger / Grand Bahama Scuba)

BAHAMAS REEF FISH (39): YELLOWTAIL DAMSELFISH

Yellowtails are just one of several damselfish species in Bahamas waters. These small fish are conspicuous not just for the bright tails that give them their name. More striking if anything – especially if seen underwater in sunlight against the coral – are the electric blue spots visible in both adults and juveniles.

Yellowtail Damselfish (©Melinda Riger / Grand Bahama Scuba)

The body of adults is dark blue to brownish to almost black 

The body of juveniles is blue

Yellowtails are a common and widespread variety of damselfish. They have a limited ability to change colour according to their surroundings, but with their bright tails and luminous blue flecks, it’s hard to see how they can look, to a predator, anything other than a tasty snack.

I have enjoyed seeing these little fish at Fowl Cay Marine Preserve, Abaco. The reef there makes for easy and rewarding snorkelling, with a wide variety of small and medium-size reef fishes to be seen. It’s an expedition I would definitely recommend to anyone wanting to see a healthy and active reef in a completely natural protected area.

I found that a video I took with a tiny camera was sadly of use only to myself. No one else would be able to make anything out due to the marked camera shake. Novices, huh? You are spared that: here’s a brief example of yellowtails swimming instead, showing the difference between juveniles and adults.

Credits: all photos, Melinda Riger / Grand Bahama Scuba; video from Desert Diving

BLAINVILLE’S BEAKED WHALES IN ABACO WATERS


Blainville's Beaked Whale, Abaco (BMMRO)

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. 

Blainville's Beaked Whale, Abaco (BMMRO)

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.

Blainville's Beaked Whale, Abaco (BMMRO)

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.

Blainville's Beaked Whale, Abaco (BMMRO)

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 Whale male, Abaco (Keith Salvesen)

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.

Blainville's Beaked Whale, Abaco (BMMRO)

All photos BMMRO except the tusked male, Keith Salvesen

AN ‘EXHILARATION’ OF ABACO DOLPHINS


Bottlenose Dolphins, Abaco Bahamas (BMMRO)

AN ‘EXHILARATION’ OF ABACO DOLPHINS

Bottlenose dolphins! Tursiops truncatus! These engagingly playful show-offs of the inshore waters round Abaco are 99.99% adorable**. It’s been a harrowing few weeks in the western Atlantic, and everyone is hoping that the 2017 hurricane season has had enough of causing death and destruction over vast swathes of vulnerable islands and on the US mainland. Some cheer is needed.

Bottlenose Dolphins, Abaco Bahamas (BMMRO)

Dolphins are good for the soul. And if you are out on a boat watching them – and especially tracking them for a whole day – every encounter reinforces the impression that all the leaping, bow-wave riding, boat under-swimming, and general sociability and interaction is often as much for sheer enjoyment as anything else. 

Bottlenose Dolphins, Abaco Bahamas (BMMRO)

Abaco is fortunate in having the HQ of the Bahamas Mammals Research Organisation (BMMRO) based at Sandy Point. That just happens to be an excellent area for bottlenose dolphin spotting in the turquoise shallows. Many sightings are made within clear sight of land. Further south, where the bright blue gives way to darker and deeper water, live the equally frolicsome Atlantic spotted dolphins. The 3 photos above were all taken on the margins of where the colour of the sea changes from light to dark.

Bottlenose Dolphins, Abaco Bahamas (BMMRO)

I’m a bit of a collector of collective nouns. For dolphins, apart from the matter-of-fact ‘group’ or ‘pod’, there is no exotic word to describe a number of them when they are having fun. No equivalent of ‘exaltation’ (larks), ‘charm’ (goldfinches) or ‘parliament’ (owls). So I’m nominating an ‘exhilaration’ as a candidate to fill the gap…

The photo above shows clearly how individual dolphins can be identified by researchers. All tend to have scars or tears to their dorsal fins that enable them to be distinguished. The closest has distinctive scars near the tip. The furthest has a W-shaped nick at the back. In fact, it could even be Rocky, a well-known dolphin on Abaco that has been sighted over many years. There are regular reports annually. I saw him myself once, in 2012, playing about in Hopetown harbour. 

STOP PRESS To demonstrate how the ID methods work, I’ve now cross-checked with the BMMRO photo ID archive. Here is Rocky’s original dorsal fin ID image (“Tt15”) from October 2010. There’s a W-shaped nick, sure, but my speculation above was wrong because overall the two fins are clearly different…

Rocky the Dolphin Tt15, from BMMRO ID photo archive

** The 0.01%? Dolphins may, rarely, be alarming for divers in circumstances I won’t repeat here (hint: to do with over-friendliness, ok? Yes, the thing that dogs do)

Credits: all photos BMMRO – and taken in the last 2 months

EYES ON STALKS: CONCH WATCH ON ABACO


Conch Man-o-War Cay, Abaco, Bahamas (Charmaine Albury)

EYES ON STALKS: CONCH WATCH ON ABACO

This is not so much about you looking at, and admiring (without salivating too much, I trust) conchs in their natural element. More about them watching you watching them – and focusing on their rather remarkable stalk-based eyes. Take a look at these examples of the ‘watcher in the shallows‘ (to misquote a well-known book title).

Conch and their eyes, Bahamas (Melinda Riger)Conch and their eyes, Bahamas (Melinda Riger)

HALF A DOZEN CONCH EYE FACTS TO PONDER

  • The eyestalks are attached to an extendable ‘snout’
  • The two eyestalks (ommatophores) are retractable within the shell
  • Their purpose is to provide a wider field of vision around the shell
  • The eyes at the tip of each eyestalk have ‘proper’ lenses, pupils and irises 
  • Amazingly, amputated eyes normally regenerate completely
  • The small projection below the eye is a ‘sensory tentacle’ or feeler

Conch and their eyes, Bahamas (Melinda Riger)Conch and their eyes, Bahamas (Melinda Riger)

CAUTIONARY WARNING

For a rather depressing view of the current state of conch populations, check out this recent article in the MIAMI HERALD. Not a great deal to be optimistic about…

I’M WATCHING YOU…

CREDITS: All remarkable ‘conch watching’ photos by Melinda Riger / Grand Bahama Scuba – except for the wonderful header image by Charmaine Albury (contributor the The Birds of Abaco), taken on Man-o-War Cay; Cindy James Pinder for the heads-up for the Miami Herald article

DOLPHINS DISPORTING IN THE BAHAMAS


Atlantic Spotted Dolphin, Bahamas (BMMRO)

DOLPHINS DISPORTING IN THE BAHAMAS

‘Disporting’. Not a word I’ve used very often. Or possibly ever. It looks a bit like ‘unsporting’, which is emphatically what dolphins are not. Basically, it just describes what dolphins are doing when you see them on the surface: amusing themselves, frolicking around in the waves, and simply enjoying themselves.Bottlenose Dolphin, Bahamas (BMMRO)

True, they are probably keeping an eye out for food… But when you have a group sociably following alongside the boat your are in, moving in front, dropping behind, diving under, and generally playing around, it’s quite hard to believe that these are completely wild creatures. They seem to be performing just for you, simply because they want to. You don’t even have to throw fish at them to earn this free display.

Atlantic Spotted Dolphin, Bahamas (BMMRO)Atlantic Spotted Dolphin, Bahamas (BMMRO) Atlantic Spotted Dolphin, Bahamas (BMMRO)

As is well-known, the BAHAMAS MARINE MAMMAL RESEARCH ORGANISATION (BMMRO) is the custodian for the welfare of these beautiful creatures for the entire Bahamas. However, being based on Abaco and carrying out the majority of the research from the HQ at Sandy Point means that many of the great images that get taken are from Abaco waters. Indeed some are taken within swimming distance (not mine) of the shore.  Bottlenose Dolphin, Bahamas (BMMRO)Bottlenose Dolphin, Bahamas (BMMRO)Bottlenose Dolphin, Bahamas (BMMRO)Bottlenose Dolphin, Bahamas (BMMRO)

The photographs featured here were taken during the last few weeks. Some are of the familiar bottlenose dolphins. The others – with speckled undersides clearly visible in the header image & below – are of Atlantic spotted dolphins. There’s even one of my own taken from the research vessel. Atlantic Spotted Dolphin, Abaco Bahamas (Keith Salvesen)Atlantic Spotted Dolphin, Bahamas (BMMRO)

For the researchers, the most important part of an individual dolphin is its dorsal fin. Unique patterns of cuts and scars mean that each dolphin sighted can be logged and their profiles built up. Some have been found in the same area for many years. They are not usually given jocular names – ‘Davy Jones’, ‘Finny Phil’ or whatever. The first time we went out on the research vessel we were slightly surprised by the practical, scientific calls during a sighting of a dolphin group: “there’s B4 again” and “over there – D5 is back”. All said fondly however – many of the dolphins are old friends.

This dolphin has a notable notch on the dorsal fin with a nick below, & a scar line – with a prominent white scar on the lower front edge Bottlenose Dolphin, Bahamas - Dorsal Fin Damage (BMMRO)

Notice how these 3 dolphins all have quite different fin profiles.  The nearest one’s fin looks unblemished, but has a paler tip. Powerful binoculars and a serious camera can pick out small  differences at a distance that the eye could notBottlenose Dolphin, Bahamas - Dorsal Fin Damage (BMMRO)

Coming soon: Manatees & Man in the Bahamas

All photos (bar one by me) BMMRO, with thanks to Diane & Charlotte, and a tip of the hat to the current interns involved in the research projects (Hi, UK Thomas!)

ONE GOOD INTERN DESERVES ANOTHER (Part 1)


Coral reef research, Australia (Oscar Ward)

ONE GOOD INTERN DESERVES ANOTHER (Part 1)

Four years ago a young English friend of ours, Oscar Ward, was lucky enough to be offered an internship with the Bahamas Marine Mammal Research Organisation (BMMRO). At the time, he was post-school, and waiting to start a degree course in marine biology at university. He had no practical experience at all, so he had to progress from the menial tasks (scraping barnacles off the bottom of the research boat) to the more adventurous (whale poop-scooping) to the scholarly (collection and analysis of samples and data, including audio file matching of whale calls for identification). The need for hard work, concentration and accuracy were made clear from the outset… and as you will see, Oscar’s short internship has stood him in very good stead during his university course.

Oscar weekending at Gilpin Point – self-sufficientBMMRO Internship - weekend off (Oscar Ward)

From a promising start on Abaco, and with 2 year’s study behind him, Oscar is currently spending the 3rd year of his 4-year course in Australia, working with The Australian Institute of Marine Science. He has been involved in a number of complex projects focussed on corals and reef life – as we all know, a matter of huge concern – and the projections for the future of the reef systems in a time of warming seas and raised acid levels. Oscar also assists PhD students, for example examining the damaging effects of parasitic worms on coral; and the effect of changing light conditions on corals.

Nurse Sharks, Great Barrier Reef (Oscar Ward)

Much of Oscar’s time has been spent doing fieldwork. Often he is at sea, monitoring and collecting samples in the Southern Great Barrier Reef, diving two or three times a day. This work is often carried out in restricted or preservation zones, and with ever-present manta rays, sharks and sea turtles around him.

Manta Ray, Great Barrier Reef (Oscar Ward)

Right now Oscar is involved with the investigations into the recent bleaching events, work that is at the forefront of serious concern for the GBR and far beyond. I have recently corresponded with him – he has definitely not forgotten that his grounding for the fieldwork and studies that he is engaged in – and very likely his career – came from his time on Abaco and the lessons he learned during his time with the BMMRO at Sandy Point.  (In part 2: another good intern, currently at Sandy Point)

Coral reef research, Australia (Oscar Ward)

All photos: Oscar Ward (the header image is taken from a research vessel – no idea how, maybe a drone with fish-eye lens?)

BLUE TANG AS REEF FILM STAR


Blue Tang, Bahamas (Melinda Riger / Grand Bahama Scuba)

BLUE TANG AS REEF FILM STAR

Last summer, the big motion picture sensation for the bird world was, of course, Pixar’s ineffably adorable creation, Piper – the ultimate ‘Chick Flick’. This little ball of cartoon fluff was not, as some thought, based on a piping plover but on a sanderling – a type of sandpiper (clue in name). This 6 minute ‘short’ preceded the main event, the hugely popular Finding Dory. You can read all about the film Piper and the birding aspects of the film HERE

Blue Tang, Bahamas (Melinda Riger / Grand Bahama Scuba)

Finding Dory is not about a fish of the dory species, of course. Voiced by Ellen DeGeneres, Dory is in fact a species of surgeonfish Paracanthurus, the familiar blue tang found on the reefs of the Bahamas. To see these fish in Abaco waters, Fowl Cays National Park is always a good bet.

Blue Tang, Bahamas (Melinda Riger / Grand Bahama Scuba)

Dory can be identified as a maturing juvenile: blue, with a yellow tail. In due course – in time for the sequel film – she will become blue all over, with perhaps the odd flash of yellow (see photos above).

In real life, a baby blue tang is in fact entirely yellow, except for blue rings around the eyes. In Pixarland, however, Dory is just an adorbs miniature version of her youthful self.

Blue Tang juvenile, Bahamas (Melinda Riger / Grand Bahama Scuba)

Blue Tang are lovely to watch as they cruise round the reefs, sometimes in large groups. Their colouring ranges from pale to dark blue. However, these are fish that are best looked at and not touched – their caudal spines are very sharp. When the fish feels in threatened, the spine is raised and can cause deep cuts, with a risk of infection.  

Still from a crummy video taken at Fowl Cays some years back to illustrate a group of blue tangBlue Tangs, Fowl Cays Nature Park, Abaco Bahamas (KS)

Blue tangs are inedible, they apparently smell unpleasant, and they can cause ciguatera. However they are popular in the aquarium trade. This is a distinct downside of highly successful films such as Finding Nemo and Finding Dory. In defiance of the well-meant and broadly ecological message of both films, the trade in clown fish and to a lesser extent blue tang was boosted by their on-screen portrayal as adorbs creatures desirable for the entertainment of mankind… ‘Nuff said.

Blue Tang, Bahamas (Melinda Riger / Grand Bahama Scuba)

Credits: All excellent photos by Melinda Riger / Grand Bahama Scuba; one pathetically bad still from a low res video, me; cartoons purloined from an online aquarium somewhere or other