BLUE CHROMIS: A FLASH OF COLOUR ON THE REEF

October 25, 2022 by Rolling Harbour

BLUE CHROMIS: A FLASH OF COLOUR ON THE REEF

Larger reef fish tend to get more attention than the tiddlers, for obvious reasons. Yet a reef would not properly exist without the small fish that drift and wriggle round the corals. Blue chromis (Chromis cyaneus) are among the first reef fish species I ever met when snorkelling at Fowl Cays.*

Blue chromis belong to the same group as damselfishes. These unmistakeable, bright reef denizens are very visible despite their tiny size. These fish are shoalers, so out on the reef you can enjoy them flickering around you as you swim along or hang in the water to admire the corals.

Like many a pretty and easily captured small fish that can be monetised once removed from its natural home environment, the blue chromis is popular for aquariums. Humans like to keep them in their own home environments safely away from oceans and reefs, unselfishly feeding the little things concocted food to keep their little lives going till the cat gets them. [Sorry, I don’t know what came over me there]

Blue chromis are adaptable and sociable, and will happily swim with other small reef fishes (as above). My own favourite combo is chromis mixed in with sergeant majors. But a shoal of them (mostly) alone is pretty special too….

I cynically mentioned ‘concocted’ food earlier. Here is one online care instruction for looking after them: “They are omnivores, meaning that they eat both meaty and plant based foods. They are not difficult to feed and will eat a variety of regular aquarium fare, frozen, live, and sometimes even dry food. Feeding them a variety of foods will help them retain their color in captivity. They sometimes feed on the algae in the tank”. So I think it’s ok to suggest that leaving the fish out on the reef might suit them better.

If tempted to ‘rescue’ some from their reef habitat, rest assured that they have been known to spawn in captivity. Blue chromis can usually be obtained for about $10-15. And don’t hold back on the frozen food (though maybe warm it up a bit before feeding time). I rest my case.

*I say ‘snorkelling’ rather than anything more impressive because I am a pathetic swimmer and I know my limitations…

Credits: Melinda Rodgers / Dive Abaco; Melinda Riger / G B Scuba

CORAL SUNSHINE: PICTURE PERFECT ABACO (9)

April 25, 2020 by Rolling Harbour

CORAL SUNSHINE: PICTURE PERFECT ABACO (9)

Off the east coast of Abaco lies one of the longest barrier reefs in the world. Some authorities suggest it is the third longest, but the exact ranking of the top dozen coral barriers is a matter for considerable debate. None of the lists I have just checked agree, except that the Great Barrier Reef is the outright winner. I suspect that the problem lies in the loosely generalised description of ‘barrier reef’ and in variations of the appropriate criteria for determining length (it may also depend on who is doing the measuring, of course).

Melinda Rogers of Dive Abaco took this bright sunlit ‘Coralscape’ in the Fowl Cays National Park. It’s a place I have tentatively snorkelled around with great pleasure, despite being in the top dozen most useless swimmers in the world (my appalling underwater videos were disqualified from the rankings for being… rank).

HIDDEN DEPTHS: LIFE ON ABACO’S CORAL REEFS

September 26, 2019 by Rolling Harbour

HIDDEN DEPTHS: LIFE ON ABACO’S CORAL REEFS

Nearly 4 weeks after the devastation of Hurricane Dorian, the island and its cays are beginning to emerge gradually from the wreckage and the desolation. The extent of the disaster on the ground is clear, not least from the aerial photos – first drone, then plane, and now Google – of ‘before’ and ‘after’.

At the stage, it isn’t possible to determine the extent to which the underwater world has been affected. The storm surge was huge and the waves were savage. The progress of the storm was slow (and it went on to stall over equally damaged Grand Bahama). Who knows the effect on the corals and other reef life for which Abaco is renowned.

This pictorial post is a reminder of how things were below the surface of Abaco waters before Dorian struck. If it lifts spirits to any degree, I shall be glad.

All these photos are by Melinda Rodgers who, with Capt Keith, are DIVE ABACO. Many will know how badly they have fared, being in the heart of Marsh Harbour. We wish them a speedy return to the wonderful enterprise they have run for many years. I’m pleased to be able to show the beauty of the reefs in happier times from their archive.

Credits: Melinda Rodgers / Dive Abaco

SHARKS! APEX PREDATORS IN THE BAHAMAS

March 29, 2018 by Rolling Harbour

SHARKS! APEX PREDATORS IN THE BAHAMAS

Immersion in current affairs these days brings inevitable acquaintance with sharks of various kinds, and all best avoided. Let’s have a look the real thing, the apex marine predators that in the Bahamas are all around you once you leave the safety of the shore. I haven’t featured them for ages, and it’s always a pleasure – a slight thrill, even.

I don’t do scuba, indeed my swimming would easily be outclassed by a competent four-year old. But I see these creatures when I’m out fishing; or as they hang in the breaking waves off the Delphi beach, watching intently for a meal.

We watch them (and stingrays) from the balcony as they lazily make their way round the margins of the wide bay, from little ‘uns to (recently) a huge bull shark. We watch as, when someone is in the water, they change course slightly to pass by them. So far, anyway…

Feeding sharks

The one that got away… (a sad sight)

I once took a rather primitive underwater camera with me while snorkelling in Fowl Cays National Park. This was several years ago, when I believed a cheap 2mb camera might turn me into one of the Blue Planet team. I was wrong. The shark I saw, apparently some 20 miles away (when I examined the image) – well, that’s its tail, top left…

Just to look at these images is to understand that when you are in the sea, you are in the sharks’ environment. They are the masters of it. They have their rules, and they are not much interested in you… unless you break them. Or so the theory goes.

This fine shark below exemplifies the power and the menace of the shark. A creature to be admired, but also to be respected.

All fantastic photos: Melinda Riger / Grand Bahama Scuba

BAHAMAS REEF FISH (39): YELLOWTAIL DAMSELFISH

October 23, 2017 by Rolling Harbour

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.

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

BLUE TANG AS REEF FILM STAR

April 19, 2017 by Rolling Harbour

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.

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 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 tang

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.

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

SILVERSIDES: BAHAMAS REEF FISH (32)

October 3, 2016 by Rolling Harbour

SILVERSIDES: BAHAMAS REEF FISH (32)

I have no idea if there is a collective noun for a large group of silversides. ‘Frenzy’ would cover it, but that is reminiscent of ‘feeding freezing’ which has a specialist meaning – and anyway, silversides are crazy even when they aren’t feeding. 24/7/12/365 as far as I can make out. I think ‘a panic of silversides’ might be the answer. They are just… all over the place at high speed. Sometimes swirling around pointlessly, other times moving in unison and suddenly all changing direction simultaneously, like a single creature made of tiny shards of silver.

There are quite a few silverside species around the world. The ones in the Bahamas are Atlantic silversides (Menidia menidia), also known in the north east of the United States as ‘spearing’. They seem to exist for two purposes. The main one is to be breakfast, lunch or dinner for larger fish, sea birds and shore birds. The other is for their usefulness in scientific research because of their sensitivity to environmental changes.

In one sense they are easy prey for predators. A determined fish will always manage a snack by swimming into the middle of a panic and (probably) simply by opening its mouth wide. On the other hand, their sheer numbers coupled with the speed and randomness of movement mean that a single may find a degree of safety in numbers. It’s hard for a predator to target any individual fish in the general melee and confusion. Silversides also favour seagrass beds, which give some shelter and protection – and a reasonably safe place to spawn. Or, as some of these photos show, they will hang around wrecks or squeeze into rocky spaces in the reef.

A panic of silversides apparently pouring like a waterfall down through a gap in the reef silversides-waterfall-abaco-kay-politano

WHAT DOES A STATIONARY ATLANTIC SILVERSIDE LOOK LIKE?

meber_u0

Some time ago we used to go to the reef at Fowl Cay Marine Preserve with Kay Politano, and I would snorkel with a small and very basic lo-res underwater camera. I was hampered by being a disgracefully feeble swimmer; by not having snorkelled for a length of time calculable in decades; and by being a complete novice at underwater photography. Despite these not inconsiderable disadvantages I managed to cobble together a few short movies on my computer (I was new to that too). Here’s one that nearly works, in that it gives an idea of what happens if you ‘swim with silversides’. I know you scuba guys all swim with sharks, but cut me some slack here please…

Photo Credits: Main photos Melinda Riger of Grand Bahama Scuba; Silverside Waterfall by Kay Politano; motionless silversides by FISHBASE.ORG. Music: Goldon Giltrap, ‘Fast Approaching’

BLUE CHROMIS: BAHAMAS REEF FISH (29)

January 22, 2016 by Rolling Harbour

BLUE CHROMIS: BAHAMAS REEF FISH (29)

The little blue chromis Chromis cyanea will be instantly familiar to any snorkeler or scuba diver on the coral reefs of the Bahamas. These ever-present small fish – 6 inches long at most – are remarkable for their iridescent deep blue colour that flashes as they dart in and out of the coral and anemones of the reef.

Blue Chromis ©Melinda Riger @ G B Scuba

Although at first sight this chromis species – one of many – looks blue all over, adults have a black dorsal stripe and black edging to their fins. They make colourful additions to aquariums, though to my mind they look far more attractive nosing about the reefs foraging for the zooplankton upon which they feed (see header image for details…)

Blue Chromis ©Melinda Riger @ GB Scuba

The blue chromis was the second fish species I encountered on my first ever reef dive, at Fowl Cay Marine Preserve with Kay Politano. The first fish was the endearingly inquisitive sergeant major with its smart black and yellow stripes which came right up to my googles to eyeball me. I loved that, even though my pitiful swimming technique meant that I had plenty of other distractions, not least remembering to breathe. Air, that is, rather than water.

Blue Chromis ©Melinda Riger @ GB Scuba

Chromis_cyanea_(blue_chromis)_(San_Salvador_Island,_Bahamas)

SO JUST HOW BIG ARE THESE FISH, COMPARED, SAY, TO A BLUE TANG?

Blue Tang with blue chromis in its wake Blue Tang with Blue Chromis © Melinda Riger @GB Scuba copy

All photos Melinda Riger of Grand Bahama Scube, except the penultimate by James St John, taken in San Salvador

THE TANG OF THE BAHAMIAN SEAS… BLUE TANG, IN FACT

January 22, 2014 by Rolling Harbour

THE TANG OF THE BAHAMIAN SEAS… BLUE TANG, IN FACT

The Blue Tang Acanthurus coeruleus is a species of Atlantic surgeonfish mostly found on coral reefs. They are known as surgeonfish because they can slice you with their sharp, spiny caudal fins. Adults are blue, ranging from a deep blue or even purplish to much paler blue.

Surprisingly, as juveniles, Blue Tang are bright yellow.

As they grow, they become blue, with the tail being the last part to lose the yellow.

Blue Tang are herbivores, cruising constantly round reefs feeding on algae. They also act as cleaners of other fish species, removing parasites. They themselves may be cleaned by gobies by visiting so-called ‘cleaning stations’. These piscine beauty parlours have a medicinal purpose as well, since cleaning helps to cure minor wounds.

These fish often move around reefs in large schools, as shown in the header image. Apart from having some value as an aquarium fish, they are not generally of use to humans. Their spiny caudal fins can cause a nasty wound. They have an unpleasant smell. Their flesh supposedly contains toxins, and they carrying a risk of the disease CIGUATERA. I can’t even find a recipe for them online – now, that is a bad sign, there are some people who will try anything. I guess best to boil them for an hour or two, drain the water, allow to cool, and throw away the fish.

FUN FACT In the Disney/Pixar film Finding Nemo, the character Dory (voiced by Ellen DeGeneres) is a blue tang.

BLUE TANG: THE MOVIE [RE-RELEASE]

“RECIPE Take one incompetent swimmer who hasn’t snorkelled in, oh, nearly 40 years. Place him over a coral reef for his first time ever. Add a small underwater camera totally alien to him. Immerse for 30 minutes in warm briny water. Lessons have been learnt for next time. Mainly, don’t keep waving the camera about; let the fish move round you rather than vice versa; and most important of all, remember to keep breathing or else…

Here is BLUE TANG: THE MOVIE (music by Adrian Legg), 45 secs of advanced camera-shake with some beautiful fish more or less in shot for most of the time. If you are prone to sea-sickness, do not enlarge the video. If you are allergic to poor photography… well, thanks for visiting.”

[vimeo https://vimeo.com/44794952]

Credits: Good pictures, Melinda; bad pictures and execrable movie, not Melinda

SOUTHERN STINGRAYS: KEEPING AN EYE ON YOU

August 15, 2013 by Rolling Harbour

SOUTHERN STINGRAYS: KEEPING AN EYE ON YOU

The SOUTHERN STINGRAY Dasyatis americana is a ‘whiptail stingray’ found in the Western Atlantic Ocean. Their habitat and personal habits – feeding and mating – are similar to those of the YELLOW STINGRAY. They live on the seabed, where they feed on small crustaceans, molluscs and fish. They expose their prey by flapping their ‘wings’ (= pectoral fins) to disturb the sand

You want to avoid treading on one of these if possible. Their tails have a serrated barb covered in venomous mucous, used for self-defence. These spines are not fatal to humans, but if you step on one it may be an experience in extreme pain to tell your grandchildren about.

Luckily they are likely to see you long before you notice them, and to swim away from your approach

IUCN LISTING: ‘DATA DEFICIENT’

Surprisingly, the ‘at risk’ status of the Southern Stingray is not known. However, as with other marine species that humans like to befriend in the wild for the perceived benefit of both parties, there are parts of the Caribbean where stingray swims involve rather more than merely swimming with and enjoying the rays in their own environment. There is organised hand-feeding with cut-up fish, even general fondling and cuddling, that can make these wild creatures seem ‘tame’. There is growing concern that such close dependent interactions with humans is not a good thing, at least for the stingrays.

A diver admiring a ray while keeping a respectful distance

If you watch out for them… they’ll keep an eye out for you

Credits: Melinda Riger of Grand Bahama Scuba; Wiki for thumbs / material; selected online trawlings

My incompetent first ever underwater video at Fowl Cay Marine Preserve, Abaco. I hadn’t snorkelled for X decades, and frankly had some breathing-and-swimming-simultaneously issues, let alone trying to hold a tiny camera steady. Still, here it is (with a proper diver’s video below)

Music credit on my vid to the fairly litigious Joe Satriani – see JS v Coldplay ‘If I could Fly’ / ‘Viva La Vida’ plagiarism case (settled, to no one’s great advantage). Hey, Joe, what you doin’ with that writ in your hand? For anyone the slightest bit interested in the alleged similarities, here is a mash-up reward for reading about stingrays. Or penalty.

‘SLOW BLUES IN SEA’: BAHAMAS REEF FISH (10)

July 4, 2013 by Rolling Harbour

‘SLOW BLUES IN SEA’: BAHAMAS REEF FISH (10)

Albert King, Lead Belly and Mike Bloomfield are prime examples of foremost bluesmen guitar-slingers who, in their own distinctive styles, favoured the key of… I’m sorry, what did you say? Oh yes, quite right. My misunderstanding. Apologies, I’ll take it from the top…

Deep blue sea. Deep blue fish. *Deep breath*. All better now. The fish below may all readily be found nosing around the coral reefs of the Bahamas in a leisurely manner. Mostly, they are feeding. Fowl Cay Marine Preserve, Abaco, is a great place for watching them. No need to have all the gear – a simple snorkel, mask and flippers, and an ability to float a bit, would be sufficient.

BLUE CHROMIS Chromis cyanea

These dazzling little blue fish will be one of the first you’ll meet (along with the omnipresent yellow and black striped sergeant majors, so friendly they will come right up to your mask). You can’t miss them. Though very small, their electric blue colouring cuts through the water even on the dullest of days up-top. They can reach 5 inches in length, but most that you see will be tiddlers. They are frequently seen in the company of larger fish.

BLUE PARROTFISH Scarus coeruleus

Parrotfish play a vital part in the ecology and health of the coral reef. They graze on algae, cleaning the coral and grinding the surface with their teeth. They take the nutrients and excrete the rest as… sand. This helps to form your beach! To find out more about their uses and habits, click PARROTFISH. You’ll find a great deal of interesting info about the species, conveniently compressed into factual bullet points.

BLUE TANG Acanthurus coeruleus

The blue tang is a type of surgeonfish, all-blue except for a yellow spot near the tail. The blueness can vary considerably, from very pale to dark. They tend to swim elegantly around in large groups.

Here are some images of schools of blue tang that I took with a cheapo underwater camera at Fowl Cay. They are a lovely sight as they drift slowly past alongside the reef. The top one also has a sergeant major (see above).

CREOLE WRASSE Clepticus parrae

This wrasse can grow up to a foot long, and may be found at considerable depths on deep-water reefs – 300 feet or more. They are active by day, and hide in rock clefts at night. This species is sociable, moving around in shoals. They develop yellow markings with age.

QUEEN TRIGGERFISH Balistes vetula

There are several species of triggerfish. The queen is capable of changing colour to match its surroundings, or (it is said) if subjected to stress. I think we have all been there. It is an aggressive and territorial fish, and its favourite prey is the sea urchin, a testament to its courage…

QUEEN ANGELFISH (JUVENILE)

I have featured this species before HERE, and strictly it as much yellow as blue. But the blue earns double points, surely, for its startling vividness. Anyway, I like the way it hangs casually upside down, and the bubbles in this photo.

Credits: Good photos – Melinda Riger of Grand Bahama Scuba; Poor photos – RH

From time to time I end a post with something musical. Just for fun (toxic concept). So here is a real “Slow Blues in C” from the fantastic guitarist Stefan Grossman off his eclectic ‘Yazoo Basin Boogie’ album. 22 quality tracks. Buy from Am*z*n – much cheaper than iT*nes.

THE CORALS OF FOWL CAY MARINE PRESERVE, ABACO [VIDEO]

November 30, 2012 by Rolling Harbour

THE CORALS OF FOWL CAY MARINE PRESERVE, ABACO

coral6

I usually have 3 or 4 planned posts on the go. Some are quick to compose, some are not. Especially those requiring technical input from the technically unsound – downloading a video, changing the file format, editing and polishing, uploading to a compatible ‘carrier’ etc. I’ve been meaning to get round to making some fish and reef videos from footage of a trip with Kay Politano of Abaco Above & Below. Now I have… coral8

If you are tolerant enough to at least start this one, which focusses on coral, can I restate the excuses? I swim like a panicking cat. I hadn’t snorkelled for a great many ~~decades~~ years until 2011. I was a stranger to underwater scenery, let alone photography. I wave my tiny camera around too excitedly, though not deliberately to inflict seasickness on hapless viewers… It is a bit less bad this time round, however. Luckily I can tell from my stats if anyone has bothered to click on the video below, and you can rely on me to trash the thing if I find a paltry (or non-existent) response. Best just to watch on the small screen, though. coral14

With those dire warnings, here is the video. I would be very interested to ID all the corals that can be seen. There are the easy ones like sea fan, elkhorn, mustard hill, brain… but what’s that one over there? No, behind the waving one…? Comments / suggestions welcome. And if you don’t much care for coral, there are some pretty fish to look at…

Music Credit: Adrian Legg’s ‘Old Friends’, from ‘Guitar Bones’

ADDENDUM JAN 13 I am really grateful to Capt Rick Guest for taking the time to view the video, and the trouble to analyse the contents. He has very helpfully highlighted many points of interest in the film, both as to coral and as to fish, so I’ll post his commentary in full, with my thanks. Of both interest and concern are Rick’s remarks about the Elkhorn Coral. I had wondered about its bleached look. It’s dying…

CORALS ETC

At 0:36 a lavender Sea Fan…(Gorgonia ventalina).
At 0:52 Yellow “Leaf”,or “Letuce Coral”. Agaricia species growing around a living soft coral called a “Sea Rod”. Soft Corals have living polyps which feed on plankton just like the hard corals.
At 1:02 More Agaricia, and a small Brain Coral at bottom. Either a Diploria, or Colpophylia species.
At 1:10 A Sergent Major fish, (Abedefduf saxatilus). One of my favorite Taxanomic names! Behind is mostly dead, Elkhorn Coral. The white areas being indicative of “White Plague”. A disease responsible for Coral Whiting…..Death!
At 1:37 A Blue Tang swims over some “Mustard Coral”… Porites porites.
At 1:55 A chubby “Chub” swims by. Likes caves and caverns and edible, but not palatable.
At 2:33-38 Much coral bleaching damage here on these Elkhorn Corals.
At 2:40-48 A Thalassoma bifaciatum,or “Blue Headed Wrasse” is swimmin’ about. This guy used to be a lady,but he’s a product of Protandric Hermaphrodism! When there’s a paucity of males in the area, a yellow female will step up and become a male for the school.
At 3:29 Lower right: a fine example of Millepora complanata,”Fire Coral”. Fire Coral is more related to Man-O-War, and jellyfish than Corals.
At 3:50 More Elkhorn Coral with White Plague
At 4:23 Brain Coral, probably Diploria clivosa

FISH FRENZY AT FOWL CAY MARINE PRESERVE, ABACO, BAHAMAS

August 13, 2012 by Rolling Harbour

FISH FRENZY AT FOWL CAY MARINE PRESERVE, ABACO

This is the first short video from footage taken in June at Fowl Cay, 2000 acres of protected coral reef waters. This was the start of another great day out snorkelling and island-hopping with dive-diva Kay Politano of ABOVE & BELOW ABACO Marsh Harbour. In due course there will be more videos of fish and coral. There is very slight evidence that lessons have been learned since last year’s erratic novice snorkeler / underwater photographer efforts. Still a way to go of course. The production process has been hampered by a major format problem between my camera chip thingy and the Mac I now use. It told me the data was unrecognisable / corrupted / damaged etc, which was massively disappointing. Then I thought of <<techno-tip>> downloading to an old PC and transferring to the Mac on a memory stick. Problem solved.

This huge swirling mass of (tens of) thousands of small fish confronted me as I round one end of the reef. I’ve never seen anything like it before, except on TV. It was an astounding, dizzy-making spectacle. When I swam into the middle of the shoal, I expected to feel tickled all over – but despite the huge numbers of fish, their speed, and their sudden and apparently random direction changes, I wasn’t conscious of feeling them at all. I assume the commotion resulted from the presence of larger fish feeding on the small ones. Or possibly from my appearance…

Music credit: Gordon Giltrap (Hofner champion) ‘Fast Approaching’

LIONFISH: FURTHER RESEARCH INTO THE CARIBBEAN POPULATION EXPLOSION

June 11, 2012 by Rolling Harbour

LIONFISH – MARMITE DENIZENS OF THE OCEAN

A short time ago I posted in some detail about the poisonous LIONFISH. I included material about the rapid increase of this Pacific species in Caribbean and Floridian waters following accidental / deliberate releases in recent years. I also included videos from Grand Bahama scuba-expert FRED RIGER to balance the anti-lionfish orthodoxy, showing that the fish in fact do some good on the reefs. The post provoked a few comments, and had a surprising number of hits. Here is some further research courtesy of the excellent SEA MONSTER which adds a dimension to the debate and concludes with a very good point… Incidentally, in a recent morning snorkelling at Fowl Cay Marine Preserve, Abaco, I did not encounter a single one of these creatures (Mrs RH was unluckily stung by a jellyfish, though…). But I guess the Preserve is well policed against such intrusive species, which are otherwise found in large numbers in the area.

Why are lionfish populations exploding across the Caribbean?

Author: John Bruno on June 6, 2012

Lionfish are an exotic fish now found throughout the Greater Caribbean and eastern Atlantic that have become incredibly abundant on many reefs, especially in the Bahamas and off North Carolina. Lionfish are piscivores (fish that eat other fish) and were introduced from the Indo-Pacific by the aquarium trade in the late 1990s off Florida. Mostly likely, someone got tired of their fish and released them purposefully.

One hypothesis explaining their great success is the absence of natural enemies; predators, parasites and competitors. This is probably compounded by the fact that few Caribbean reefs have any predators left that could eat them (thanks to overfishing).

Another – and I think much more likely explanation – is because there is so much to eat in the Caribbean! Not because there are more fish, but because it is so much easier to catch them. Unlike fish in the Indo-Pacific, native Caribbean fishes do not appear to recognize lionfish as a potential threat. So the lionfish gobble them up, grow faster, make more babies, spread to new islands, etc.

Case in point: My lab group was working in Belize last week on the lionfish invasion. One of the things we were doing was collecting the otoliths and gonads from lionfish that we speared on a number of reefs to compare their fitness across the Caribbean (e.g., on reefs with and without native predators, etc). We also looked at stomach contents and many of them had parrotfishes in their tummies or still in their throats! The photo above is of the eggs from one lionfish we caught near Glovers Reef Atoll and the partial contents of it’s stomach (a juvenile striped parrotfish)!

Lionfish appear to be little more than machines that convert parrotfishes to baby lionfishes. Which is pretty much the purpose of all animals (consuming others and transforming them into your own genotype and species). But jeez, couldn’t those aquarium hobbyists have released a herbivore that could be converting macroalgae to fish biomass? That would have been much more useful.