The reefs of the northern Bahamas, as elsewhere in the world, are affected by two significant factors: climate change and pollution. Stepping carefully over the sharp pointy rocks of controversy, I’ve avoided the term ‘global warming’ and any associated implication that humans (oh, and methane from cows) are largely to blame for the first factor; but on any view, ocean pollution is the responsibility of mankind (and not even the cows).
That said, an exploration of the reefs of Abaco or Grand Bahama will reveal not just the astounding variety of mobile marine life but also the plentiful and colourful static marine life – for example the beautiful and Christmassy orange cup coral in the header image. Here are some more corals from the reefs, with a mix of sponges added in.
This rather intriguing photo shows a hermit crab’s conch home that presumably the occupant grew out of and left behind in the delicate coral branches as it went search of a more spacious shell dwelling.
Credits: All these wonderful photos are by Melinda Riger of Grand Bahama Scuba; tendentious reef health observations are mine own…
The jocularly-named WTF? series is designed to shed an underwater spotlight on some of the odder denizens of the coral reefs and surrounding waters. I don’t want to earn a reputation for being ‘lookist’, but frankly the appearance of some of these creatures – I give you BATFISH or FROGFISH or REMORAS as examples – is baffling. The filefish group is not as extreme as some in the downright weird category, but if you see one you might just find yourself muttering into your facemask “wtf?”
Filefish (Monacanthidae) are found in tropical and subtropical oceans worldwide. They are related to triggerfish, trunkfish and pufferfish, and have regional names that include leatherjacket, foolfish, and shingle. There are more than 100 species of filefish, of which only a few are found in Bahamian waters. The species featured here are a mix of scrawled, white-spotted and orange-spotted filefish.
HOW DID THEY GET THE NAME?
In the image above, you can just see a flattened spine on top, above the eye and pointing backwards. This is the ‘retracted’ state. There is a small secondary spine that serves to prop up the main spine when it is in the upright position. This is it seems, the file – although the Greek-derived family name Monacanthidae literally means ‘one thorn’. So why isn’t it a thornfish, you may well ask. And I may well not respond.
This filefish’s ‘spine’ seems to have flopped over to one side
These fish have snouts with small mouths and specialized teeth with an inner and outer set on each jaw. They are to an extent shapeshifters, and can quickly make themselves appear larger for defensive purposes. In some individual species, there are marked differences in body shape and coloration.
An orange-spotted filefish with its spine erect, making for a cave – a place of safety
The fins of a filefish are small, and they are rather sedate swimmers. Sometimes they simply like to drift with their heads pointed downwards, eyeing patches of seagrass or seaweed for prey. Some species are largely vegetarian. Others eat small invertebrates. Some even feed on corals. Their predators – especially the juveniles – include tuna and dolphins (mahi-mahi).
ADDITIONCapt Rick Guest has helpfully expanded on juvenile filefish:“The juveniles hang under sea weed and flotsam eating small shrimps and crabs there. They, in turn become food for Mahi and other pelagic fish. The main thing with these guys is that the bigger they are, the more likely they are to be Ciguateric”.
At his suggestion I will write a post about the problem of the Ciguatera disease when I have had some time to do the research.
ARE THEY EDIBLE?
Good question. The answer, broadly is yes, though I don’t know if that applies to all species of filefish. They are certainly eaten in large quantities in the Far East. I don’t know about the Bahamas or the wider Caribbean. If anyone does, could you very kindly add a comment to this post. Recipes welcome!
Hawksbill turtles are found throughout the tropical waters of the Atlantic, Pacific, and Indian Oceans. They avoid deep waters, preferring coastlines where sponges are abundant and sandy nesting sites are within reach. They are normally found near reefs rich in the sponges they like to feed on. Hawksbills are omnivorous and will also eat molluscs, marine algae, crustaceans, sea urchins, fish, and jellyfish.
Hawksbill Turtle Range (Nat Geo)
WHY ARE HAWKSBILLS CRITICALLY ENDANGERED?
Despite the protection of their shells, turtles are predated on by large fish, sharks, octopuses, and (unlawfully) humans.
Hawksbills are slow breeders, mating only every 2 or 3 years, which is the first drawback to species survival.
Having laid the resulting eggs on a beach, the female returns to the sea. The eggs hatch after a couple of months. Unless, of course, some creature – and that includes humans – has got to them first…
Hatchlings are hugely vulnerable as they make their way from the nest site to the sea. However fast they scurry along, crabs and in particular flocks of gulls are faster. Also, they may have to negotiate impossible obstacles washed up onto the beach (see below). The attrition rate of tiny turtles at this stage is very considerable.
SO, HUMANS ARE BASICALLY IN THE CLEAR, RIGHT?
Humans can take most of the credit for the turtles plight leading to their IUCN ‘critically endangered’ listing, in these mostly illegal ways:
Killing adult turtles for food or…
…for their beautiful shells
Digging up turtle nesting sites to take the eggs as food
Catching turtles in fishing nets as unintended but often inevitableBYCATCH
Providing a rich stew of plastic, styrofoam & other dietary or physical hazards in the ocean
Degrading or destroying the nesting sites, & indeed the reefs on which turtles depend
A hatchling tries to clamber over beach rubbish to get to the sea
A straw is extracted from a turtle’s nostril (small pics on purpose – I spared you the long video)
This poor creature was found just in time
Assorted plastic effects (the turtle trapped in the beach chair was off Man-o-War Cay)
PLEASE CAN WE GO BACK TO HAPPY PICTURES?
Healthy hawksbills happily living the northern Bahamas reef life
Credits: Melinda Riger & Virginia Cooper of Grand Bahama Scuba for the main photos; Melissa Maura, Nathan Robinson, Friends of the Environment and other FB sharers for the small images; National Geographic for range chart and information
The Atlantic spadefish looks very much like an angelfish, and indeed it is called that – or ‘white angelfish’ – in some places. Actually, it has quite a collection of colloquial names of which ‘moonfish’ is the most attractive sounding. It is not a true angelfish, however, and despite appearances it has a kinship with the weird and wonderful BATFISH.
Unlike the batfish, the spadefish is demonstrably fishlike AND edible. They can grow up to 3 foot long and have become a popular gamefish for three good reasons: they are abundant; they fight hard; and they are dinner. The perfect combination.
All photos: Melinda Riger of Grand Bahama Scuba, with thanks
“OPHELIA READY FOR HAMLET”: BAHAMAS REEF FISH (27)
It’s a couple of years since I originally posted about the various species of HAMLET that inhabit the reefs of the Bahamas. I feel you are (geddit?) ready to see some more of these colourful little fish. Last time out, I worked over the Shakespearean possibilities quite thoroughly so I’ll spare you a repeat (apart from the inevitable title pun). If you really want to revisit the famous Hamlet Cigar ad or hear the theme music (Bach’s Air on a G String, shamelessly ‘borrowed’ by Procol Harum for ‘A Whiter Shade of Pale), you’ll find them HERE. Or just move straight on to 5 related but very different looking Hamlets cruising the Bahamas coral reefs.
INDIGO HAMLET
BARRED HAMLET
BLACK HAMLET
SHY HAMLET
BUTTER HAMLET
Credits: all photos Melinda Riger of Grand Bahama Scuba
Adult male Blainville’s Beaked Whale with barnacle-encrusted teeth protruding from its lower jaw
WHALE TALES FROM ABACO (2): MALE BLAINVILLE’S BEAKED WHALE
This second post about the Blainville’s Beaked Whales of Abaco, Bahamas, relates to a prolonged encounter with a group of mothers, calves and a male. This was our second BBW sighting on the same day in March: the first is described HERE. Click the link to find out more details about these wonderful creatures, with plenty of close-up photos.
We had been invited by Charlotte and Diane of the Bahamas Marine Mammal Research Organisation BMMRO to spend a day with them on the research boat. This was our first chance to get close to whales, a chance made far more likely by (a) being with experts and (b) their specialist equipment…
Our first sighting was a short distance south of Rocky Point, as we moved into the deeper, darker ocean waters of the Bahama canyon, with the shoreline still clearly visible. We then visited HOLE-IN-THE-WALL in the RHIB and took a close look from the sea at the damage and destruction of the famous Hole caused by HURRICANE SANDY.
On the way back we paused as we got to the same area where we had seen the group earlier in the day. Within minutes, several whales came straight towards us. This photo shows 3 adults and, almost submerged, a calf.
For the next hour or so, they played around the boat like very large dolphins moving in slow motion. Usually these whales make a deep dive every 20 minutes or so and stay underwater for about the same time before resurfacing. These ones stayed with us throughout.
3 adults with 2 calves
Mostly they stayed quite – or very – close to the boat. Sometimes they swam across the bow or even under the boat. From time to time, they would move off some distance. Each time we thought they were moving on, and each time they soon returned. After a while the females and calves were joined by another whale – the less common sighting of a male replete with barnacle-encrusted teeth protruding upwards from his lower jaw.
The male initially stayed slightly further away from the boat than the others, perhaps assessing the threat to the group. Then he too joined in, passing and repassing the boat, swimming away and returning, remaining on the surface and offering a wonderful view of his noble head (see header image and below).
Looking at my photos later, I realised that a second male must have joined the group for a short time. The image below shows a male with far fewer barnacles – certainly not the male we had been watching.
It was remarkable to see these huge creatures behaving in much the same way as dolphins, swimming playfully around and under a boat, moving away, then returning for more. These whales are some 15 feet long and weigh about 2000 pounds. They were inquisitive, unafraid (even with calves in the group) and gentle. Maybe they sensed that they have been to subject of years of intricate research by Diane and Charlotte that will materially assist with the preservation their species. More likely, the group were simply enjoying themselves in the sun with a peaceful intruder in their territory.
You don’t have to go miles offshore to see whales in Abaco waters
BMMRO research RHIB with Diane BMMRO HQ, Sandy Point, Abaco
Credits: All photos RH except one; Charlotte & Diane for a brilliant day out; Mr Blainville for a brilliant whale; Mrs RH for snapping me snapping the whale – a photograph that was featured in a competition in the Guardian Newspaper.
MARINE DEBRIS: BALLOONS – WHAT GOES UP MUST COME DOWN…
Two sisters, Chelsea and Danielle, grew up by a Florida beach. With their parents,they learned from an early age to collect rubbish from the beach and to keep it clean. When they were little, the problems weren’t so great. Gradually, the tide changed. Literally. And indeed littorally. As is a common experience with any shoreline these days however remote and unspoilt, all manner of debris washes in on every tide, from plastic straws to SPACE ROCKET FAIRINGS. There has been a massive increase in ‘single-use’ plastic items. Most of it will take years, decades or even centuries to decompose. And there are deflated balloons, with their strings.
A typical haul of a lot of plastic and several balloons from just one beach collection
As ‘business’ on the Florida beach increased, so it became clear that balloons were becoming a significant problem. The increasing popularity of mass releases of balloons at sports events, civic or institutional occasions, and smaller celebrations means 100s or even 1000s of balloons being released into the sky. In most cases they are filled with helium – a finite resource – which carries them high over the earth. Very festive. Then the problems begin. They get caught in thermals, winds and crosswinds, gales and storms. Whether onto land or water, they all have to come down eventually. The problems caused therefore affect creatures inland, on the shoreline and out to sea.
Eventually the sisters decided to take action. They started a website BALLOONSBLOW.ORG, linked to a FB page. They post regularly about their beach clean-ups, now extended to other beaches on the south-west coast of Florida. They also produce balloon-based information sheets and flyers such as these:
I have a folder in which I keep some horrific images of incapacitated, dying or dead creatures. I use them sparingly because in the main they are upsetting. Almost every one of them involves entanglement in or ingestion of such materials as plastic, mylar, styrofoam, rubber or latex. Here are just 3 examples involving balloon strings – I’ll spare you others I have collected (e.g. a turtle that died trying to excrete the remains of a balloon).
I don’t have a down on ‘fun’ – and nor do Chelsea and Lucy I’m sure. But, now in their 20s, they have had years of direct hands-on experience clearing their beach and one can see why they decided to take wider action. From one area they have accumulated a vast collection of balloons that will take many decades to break down. Even then, the degraded pieces and micro-pieces will be eaten by fish, turtles and birds.
Here’s an illustration of the problem of creatures nibbling away at latex
The Delphi beach is very regularly cleaned up, of course, but there’s nothing that can be done to stem the arrival of debris large and small on every tide. Beautiful and remote though the one-mile curved strand may be, one cannot walk far without seeing plastic of some description. As a matter of interest, I tried a test: walking south on the beach in the tide-line, how long would it take to find balloon evidence? The answer was, less than 10 minutes.
The decomposition rate of various common items
The Balloons Blow website is constructive in offering festive alternatives to mass balloon releases, rather than merely chronicling the downsides. The balloons and other plastic junk mostly arrives from the western fringes of the North Atlantic Gyre, in the Sargasso Sea, where the trash gets caught in the sargassum and is eventually forced onto the shoreline by currents, winds and tides.
North Atlantic Gyre hotspot infographic
This post has concentrated on the dangers to wildlife caused by latex and mylar balloons that are sometimes claimed to be biodegradable but are not. There’s more to be said about plastic marine trash, but I’ll keep that for another day.
The giant anemone is found in the shallow reefs and lagoons of the Caribbean and western Atlantic. These are, of course, animals and not plants, with many tentacles that surround their mouth. They attach themselves to rock or in rock crevices, mooring themselves securely against the swell of the waves.
Giant anemone with ‘Speckles’, a spotted moray eel
ARE THEY USEFUL?
One important feature of a healthy anemone population is the shelter they give to certain small fish and cleaner shrimp species. They act as bases for FISH CLEANINGactivities, a vital role in the undersea community.
HOW DO THEY HAVE… ERM… SEX?
The sex lives of anemones seems particularly complicated (as they would doubtless think about humans). Cutting to the chase, reproduction involves the synchronous spawning of eggs and sperm, with fertilisation occurring in the surrounding water. The fertilised eggs become larval and spread in the water column, which increases their chances of survival. They settle on the BENTHOS, where they develop a “pedal leg” (rather in the manner of a gastropod) which in due course they will use to move from A to… A plus a very short distance.
These anemones come in many colours. The tentacles often have tips of various hues, and are the only free-floating part of the animal. The body is safely attached to the rock.
The giant anemone has primitive defensive mechanisms. It needs them, because it crawls so slowly that successful escape by moving is unlikely. Instead they reduce their size by drawing their tentacles into, or as close as possible to, their gastric cavity. They make room for this by forcing most of the water out. This reduces their overall size and of course removes – or at least diminishes – the ”50 colourful tentacles waving around” predator-magnet problem. But also…
…they have a trump card. The tips of the giant anemones’ tentacles are packed with cells that contain a toxin. When stimulated, the cells (‘nemocysts’) “explode out of the capsule, impaling the attacker”. The toxin is then discharged, causing extreme pain and paralysis. How cool is that? It’s the superpower we’d all like to have! Or is that just me?
This is also how an anemone feeds, by quickly paralyzing its prey with the ‘toxic tentacles of doom’. The prey is moved to the mouth and swallowed whole…
Credits: Melinda Riger of Grand Bahama Scuba, with thanks as always
The creole wrasse is a small wrasse species, with adult males reaching about 12 inches long. During its life, a creole wrasse changes colour significantly. A juvenile is almost completely violet-purple. As it matures, it develops patches of yellow on the rear part of its body.
Creole wrasse are found throughout the tropical and subtropical waters of the western Atlantic from Florida south to Brazil. The habitat includes Bermuda, the Caribbean Sea, and the Gulf of Mexico.
Creole wrasse are social fish that live in groups around coral reefs. They are found in shallow water, but may also be seen as deep as 100m.
The groups of wrasse feed on plankton, small jellyfish, pelagicTUNICATES, and invertebrate larvae. These fish are active in groups by day. At night each fish finds its own safe crevice in the reef to sleep.
ANYTHING ELSE WE NEED TO KNOW?
Yes indeed. Their intriguing breeding regime – how unlike our own dear species. The creole wrasse is aprotogynous hermaphrodite. The largest fish in a group is a dominant breeding male, while smaller fish remain female. If the dominant male dies, the largest female changes sex. The mature males congregate atleksto breed, at which they display and are approached by females before mating with them. [note: these leks are reminiscent of certain clubs in the less reputable parts of some towns and cities. Or so I am told]
It’s been a while since the last Rolling Harbour musical diversion, but the colour of this wrasse nudged my memory back to 1968 and DP’s first album (line-up Mk 1 of several hundred, or so it seems). Hence the post title. Anyone who remembers this ‘wasn’t there’. Anyone who doesn’t obviously wasn’t there either…
I don’t think this guy thinks much of that. And quite right too
All phish photos by Melinda; DP cover borrowed from Am@z@n; MP3 moi
Melinda Riger, doyenne of the deep and photographer to the stars (brittle stars, basket stars, starfish etc), undertook her 5000th dive a few days ago. She swims with sharks almost daily, and points her lens at the varied reef life she encounters along the way. Her gold prize for the dive turned out to be one of the smallest creatures she encountered: the seahorse. Hippocampus (Ancient Greek: Ἵππος, horse and Κάμπος, sea monster) is a unique fish, deriving from the pipefish, with more than 50 species known worldwide. I can feel a Rolling Harbour fact list coming on…
10 SEAHORSE FACTS TO DAZZLE YOUR FRIENDS WITH
Only seahorses and razorfish swim upright / vertically all the time
Their tails are prehensile and enable them to moor on coral, seagrass etc
They have no scales, but skin stretched over bony plates arranged in rings
The ‘coronet’ on a seahorse’s head is unique to the individual
Seahorses are pathetic swimmers: the slowest have a top speed of 5′ per hour
They feed by ambush, rotating the head and sucking prey in with their snout
A seahorse’s eyes can move independently of each other, like a chameleon
The Bahamas is home to H. erectus and the dwarf seahorse H. zosterae
Despite rumours, they don’t mate for life. Some may stay together for a season
The smallest seahorse in the world – the pygmy – is a maximum of 15mm long
MAKING BABY SEAHORSES: A MOST UNUSUAL ARRANGEMENT
There’s no getting round it: seahorse courtship and reproduction is highly unusual. Here is a summary of how it goes (there’s a lot more to it, but life is short):
COURTING This may last for many days. They may change colour; they swim together; they entwine tails; they attach themselves to the same strand of coral or seagrass and turn slowly round it in unison (a so-called ‘pre-dawn’ dance). The final courtship dance may last several hours while the male & female prepare for the next stage.
EGG TRANSFER When the time is right the female transfers her eggs – hundreds of them – via herovipositorto the male, in the process of which they are fertilised. Handily, he has inflated a special egg pouch located on his abdomen. She then buggers off.
GESTATION The fertilised eggs grow inside the egg pouch of the male and develop into baby seahorses. This process may take from 10 days to a few weeks. During this time, the female will visit for a short ‘morning greeting’ and some intertwining action.
‘BIRTH’ In due course the male ejects the baby seahorses from his pouch using muscular contractions. These may number from five to (get this!) 2,500 at a time; on average 100–1000. Job done. Then the tiny seahorse babies are on on their own…
THREATS TO SEAHORSES
The attrition rate of baby seahorses through predation is high (as for most fish species), but the prolific breeding rate reduces the effect on the overall populations. As so often, there are human-related threats, not least habitat destruction, overfishing and pollution. There’s a less expected problem: the importance of seahorses in Chinese medicine. Their presumed healing qualities are used to treat impotence, wheezing, enuresis, pain and to assist labour. For these purposes, some 20 million seahorses a year are caught and sold. Increasingly they are reduced to pill or capsule form.
Seahorse values depend on the species, but weight for weight dried seahorses retail for *unbelieving face* more than the price of silver and almost that of gold in Asia, from US$600 to $3000 per kilogram. Ours not to reason why.
USELESS SEAHORSE FACTS
Seahorse is an anagram of seashore
The Seahorses were an English rock band, formed in 1996 by guitarist John Squire following his departure from The Stone Roses. They split in 1999
Devendra Banhart’s song ‘Seahorse’ contains these inspiring lyrics: I wanna be a little seahorse I wanna be a little seahorse A little seahorse I wanna be a little seahorse I wanna be a little seahorse I wanna be a little seahorse I wanna be a little seahorse
I’m losing the will to live. Let’s meet Otis.
Introducing Otis, Melinda’s seahorse that lives under her dock
SEAHORSE MATING DANCE (4 MINS)
MALE SEAHORSE GIVING BIRTH
All photos: many thanks to Melinda Riger of Grand Bahama Scuba; sources, many and manifold including Wiki which is pretty good on this kind of thing! Fab seahorse gif by Alex Konahin
For some time now, there has been understandable concern about the increasing evidence of mangrove die-back in the Abaco Marls and elsewhere in Abaco waters. Scientific investigations are ongoing and you will find some of the survey results so far on the excellent Abaco Scientist interactive mapHERE. You’ll find other relevant and authoritative mangrove material if you check out theBLOGmenu of the website.
The ‘200 sq. miles’ in my map is debatable, depending what one includes. Other estimates are of 300 or even 400 sq. miles. Whichever, the Marls cover a massive area of mangroves, islets, flats, channels and wonderfully diverse wildlife. A large proportion of the many species – fish, birds, turtles etc – depend on the complex ecology of the mangroves for food, shelter and breeding. Depletion of the mangroves from whatever cause will have a direct effect on the creatures of the Marls.
Ryann Rossi, a PhD student with North Carolina State University, has been researching the worrying phenomenon of mangrove die-back in the Marls this summer. She has written an interesting and informative account (conveniently in the RH ‘Facts about…’ style) that was published in Abaco Scientist last week. The blue links will take you to the ABSCI site for further information on each topic. I’m grateful to Ryann and ABSCI for permission to use the material.
Five Things to Know About the Mangrove Die-back in The Marls (at this point, anyway)
1. This die-back appears to be the result of multiple stressors acting together. Think of it in the sense of our own body – when our immune system is down, we are often more susceptible to getting sick. The same thing is likely happening to the mangroves.
2. It appears as though a fungal disease may be taking advantage of already stressed mangroves and causing die-back. We did preliminary surveys across Abaco and found fungal lesionsnearly everywhere. However, the fungus was present in different densities in different areas. In the die-back area nearly all the leaves remaining on trees have lesions. We think that this pathogen capitalized on the mangroves being weakened by other stressors such as hurricanes, which cause extensive leaf drop, change in the movement of water, change in sedimentation and erosion.
3. We are still working on identifying the pathogen associated with the lesions we’ve found. We are confident that it is a fungus and are currently growing fungal cultures in the lab to examine defining morphological characteristics in addition to using DNA sequencing to identify the culprit.
4. We have documented the presence of the Robust Bush Cricket (Tafalisca eleuthera) in the die-back areas as well as other areas with high densities of lesions. These crickets are documented to consume Red and White mangrove leaves. As such, we were concerned about their potential role in die-back. We set out a caging experiment to exclude the crickets from certain dwarf Red mangrove trees to see just how much grazing they may be doing in the die-back area. This experiment is ongoing.
5. The take home: there is likely more than one causal agent of the die-back in The Marls. Many factors govern mangrove productivity and functioning: nutrient availability, salinity, sedimentation rate, herbivory, and disease are just a few of the factors that contribute to overall mangrove function making it very difficult to pin point which factors may be driving the die-off. On the bright side, we are confident that we have a lead on the causes and we are working hard in the field and laboratory to fully understand what is going on in The Marls.
This summer Stephanie Archer and I continued research efforts focused on determining the cause of the mangrove die-off in The Marls (work funded by the National Science Foundation). Our efforts were predominantly focused on the fungal pathogen we found associated with the die-off site. We created a small citizen science and outreach project to document the presence or absence of the pathogen across Abaco. This project consisted of short surveys and leaf collections. In total, 92 areas were surveyed including locations from Abaco and San Salvador. We also took this outreach project to the annual Bahamas Reef Environment Education Foundation (BREEF) teacher training conference. There we disseminated survey packets to teachers from islands throughout The Bahamas who will help us collect more data on the presence (or absence) of this pathogen on other Islands.
Three men on a skiff – Abaco Marls
On Abaco, we constructed an experiment to investigate the role of grazing and the presence of fungal lesions on Red mangroves. We simulated grazing using crafting scissors to cut small sections on 600 leaves in 4 different mangrove creeks. We observed the leaves for 28 days to determine if cutting leaves predisposed leaves to fungal infection. At these sites we also trapped for insects to gain an idea of what kind of grazers may be chewing on the leaves. We also did a series of disease incidence surveys that will be routinely monitored for disease progress over the next 2 years. These surveys will allow us to systematically track the progress of the disease. In addition to our field work, we spent many hours in the laboratory isolating fungi from leaves to grow in culture. These cultures were brought back to North Carolina State University and will be sequenced in order to help us identify the fungal pathogen responsible for making the lesions on the mangrove leaves.
Gina (adult female) and her calf – last seen August 6th, 2015 in Spanish Wells Key feature – numerous paddle cuts; white oval scar on left side of back; linear scar on posterior right side of body
BAHAMAS MANATEE MAGIC ON ABACO & BEYOND
Four years ago, there were no manatees in Abaco waters. Then a couple of adventuresome sirenians made the trip over from the Berry Is. and since then, there have been at least one, sometimes two and occasionally three resident on Abaco. And for slow, gentle, animals they certainly move around, too. In the past, I wrote quite often about the manatees, charting their journeys based on satellite tracking and sightings. I reported the tantalising prospect of the young male, Randy, hooking up with young female Georgie in Cherokee Sound, only to turn back when he reached Little Harbour. You can read more about the manatees of Abaco on my manatee pageHERE.
Georgie’s epic trip (Sept 12) continued to Cherokee Sound; and Randy’s ‘pursuit’ (Sept 14)
The most comprehensive source for Bahamas Manatee information is now to be found by joining the open Facebook group BAHAMA MANATEE CLUB, skilfully curated by Felice Leanne Knowles. There, you can follow the meanderings of your favourite Abaco manatee, watching as he or she moves around the island and cays. In recent months there have been sightings of single or pairs of manatees in several places, including Sandy Point, Little harbour, Marsh Harbour, Schooner Bay and Hope Town Harbour (where two are right now). Here’s an excellent example of how, just like a Beach Boy, an Abaco manatee gets around. In July, Randy moved from Sandy Point to Schooner Bay in 2 days. The big question is, did he travel round the longer top route, as he has in the past; or (more likely in the time taken) via Hole-in-the-Wall?
Randy the Abaco Manatee goes swimabout
Felice has just produced a great map that shows the present locations of all the Bahamas manatees currently recorded. She has also supplied photos and information about them. Most have names and are well-known to the research team and the locals where they stay. There is one new calf – Gina’s – this year. One or two manatees are new on the scene and have yet to be identified or named.
Manatees Throughout The Bahamas
The map shows the last location of the named manatees. The pink dots label females, the green dots label males, and the yellow dots label unknown manatees. The number of unknown manatees has been approximated to reduce error. The photos are of the individual manatees with dates and specific locations of their most recent sighting. We do not have enough data and photos to confirm the unknowns labeled. Any help from the public would be greatly appreciated. Send sighting reports tohttp://www.bahamaswhales.org/sightings/index.htmlNB Felice points out“Full body and paddle photos are very important for the identification of manatees. Facial shots do not provide enough information for a manatee to be identified”
Georgie (sub-adult female) Last seen in Casuarina, Abaco 9th July, 2015 Key feature – 2 pink scars on the right posterior of her body
Randy (sub-adult male) Last sighted in Hope Town August 12th, 2015 Key feature – triangle cut on right side of paddle
Unknown (adult, presumed female) with Randy Last seen in Hope Town August 12th, 2015 Key feature – 3 prop scars on the posterior right side of body
Gina’s Calf Last seen August 6th, Spanish Wells Key feature – none yet, just really tiny!
Blackbeard (adult male) Last seen in Lyford Cay August 13th, 2015 Key features – triangle cut on right side of paddle (similar to Randy’s); oval scar on centre of paddle; three prop scars on the back and linear scar
Kong (adult male) Last seen in Great Harbour Cay Marina, February 25th, 2015 Key feature – triangle cut on the left side of paddle; linear scar across the back; oval scar on the back near paddle
J.J. (sub-adult female) Last seen in Great Harbour Cay Marina, Berry Islands, February 25th, 2015 Key feature – 3 small semi-circular cuts out of paddle at the very end
Rita (adult female) Last seen 23rd March, 2014 Hawks Nest Marine, Cat Island Key feature – Large triangle cut on right side of paddle; two small triangular cuts side by side forming a “w” on the left side of paddle
Unknown adult, West Grand Bahama – Key feature: too distant!
You may have noticed that several of the manatees shown carry scars attributable to prop wounds. Almost all carry injuries of some sort. Because manatees are slow, gentle, inquisitive and trusting creatures, they are especially vulnerable in harbour areas for obvious reasons. Elsewhere than the Bahamas, boat-strike is one of the main causes of manatee mortality. The BMMRO recently issued the above advisory notice because of the uncertainty about the rights and wrongs of watering manatees from docks with hoses and feeding them lettuce etc. Overall the message is that, though creatures of wonder, they are better off being admired but left to their own devices. They are adept at finding the fresh water sources they need, and their sea-grass diet is amply provided for. Dependence on humans, however well-meaning, is actually harmful.
Credits: first and foremost, Felice Leanne Knowles; also BMMRO, Charlotte, & Diane for permission to make free with their material and photos from the get-go; any other photographers of the manatees shown and posted via BMMRO / FLK (Cha Boyce, Jessica Mullen,Otis Wilhoyte I think, maybe others…)
WHALE TALES FROM ABACO (1): BLAINVILLE’S BEAKED WHALES
Back in March we were invited by Charlotte and Diane of the Bahamas Marine Mammal Research Organisation BMMRO to spend a day out with them on the research boat, a chance we jumped at. I had been writing on and off about the organisation’s whale, dolphin and manatee research since the very early days of this blog. We’d seen bottlenose dolphins in Abaco waters, but never whales. This was the big day…
Our first sighting was a short distance south of Rocky Point, as we moved beyond the turquoise water of the low sandbanks into the deeper, darker ocean waters of the Bahama canyon beyond. Whale territory. The shoreline was plainly in view to the east; and to the north, on the horizon, was the massive bulk of the ‘fun ship’ parked at Castaway (Gorda) cay.
Beaked whale or fun ship for a day out? You decide…
A Blainville’s beaked whale noses towards the research vessel
The Blainville’s beaked whale (Mesoplodon densirostris) is also known slightly less politely as the dense-beaked whale. It is named forthe French zoologist Henri de Blainville who first described the species in 1817 based on his examinations of a piece of jaw or ‘rostrum’ — the heaviest bone he had ever come across — which resulted in the name densirostris (Latin for “dense beak”).
The beak breaks the surface
The BMMRO has carried out intensive research on the species for a number of years in the northern Bahamas, with detailed documentation of sightings and photo identification of individual animals. More recently, these whales have been the subject of incredibly detailed research into their species intercommunication through vocalisations – mainly clicks and click patterns. To view Charlotte’s PhD thesis for St Andrew’s University click HERE (and many congratulations, Dr Dunn…). Just reading the contents table will give a good idea of the scope and complexity of the research.
The blowhole, used for breathing, in close-up. You can hear this in the video below.
Our amazing first encounter with 6 whales lasted nearly an hour. Usually, they stay near the surface for 20 minutes or so, then they do a deep dive lasting roughly 20 minutes before resurfacing. But on this occasion they behaved more like huge dolphins, swimming towards the boat, around it, under it, then drifting away again before returning.
Given their length of some 15 feet and weight of about 2000 pounds, it was a extraordinary experience to see them at such close quarters.
The Blainville’s range is extensive and in general terms they may be found in tropical and sub-tropical waters worldwide. They are by no means uncommon, but apart from the data collected by the BMMRO it seems that comparatively little is known about them. Their diet is thought to consist mainly of squid found at depth. They are protected by a variety of Agreements, Memoranda of Understanding, Protocols and so forth throughout the worldwide range.
The research boat is equipped with sonar the can pick up the click and whistles of whales and dolphins from a considerable distance. It was remarkable to watch a group of cetaceans and to be able to hear them loudly and animatedly communicating with each other..
Another vital aspect of the research is poop scooping. As soon as the whales had gathered round the boat, Charlotte slid into the water with her scoop net… the cloudy poop yields a mass of information about an individual creature. I wrote about this interesting job, often tasked to interns (who practice with coffee grounds) in‘FAMILIAR FECES’.
Charlotte expertly wields the poop scoop
Then, all too soon, it was deep dive time. The whales moved off from the boat and slowly, without show or splash, disappeared. And we went to investigate HOLE-IN-THE-WALL at close quarters. The next post will feature an adult male Blainville’s beaked whale, with his massive barnacle-encrusted teeth protruding upwards from his lower jaw.
The remains of a neat and undramatic deep dive
In this very short video of two whales right by the boat: you can actually hear their breathing.
BMMRO research RHIB with Diane BMMRO HQ, Sandy Point, Abaco
Credits: All photos RH; Charlotte & Diane for a brilliant day out; Mr Blainville for a brilliant whale
In this second part of the look atBimini’s Marine Protected Area Campaignand the photographs that illustrate the vital importance of the mangroves, reefs, sea grass and pristine sea to marine life, it’s time to look at some of the the smaller sea creatures in their underwater habitat. Many of these are vulnerable to changes in their environment; some are already rare.
At first glance you may wonder why these little fish are worth including. The answer lies in the food chain. The clean environment in which these bait fish thrive provides food for larger species and so on up the chain… If silversides ceased to exist, a vital source of marine nutrition would be lost.
Loggerhead Hatchling (Bimini’s Marine Protected Area Campaign)
A VISIT TO BIMINI’S MARINE ENVIRONMENT (1)
Abaco is fortunate already to have special conservation areas, both on land (e.g. the huge National Park) and at sea (e.g. Fowl Cay Marine Preserve). Other preserves are in active stages of development. Elsewhere in the Bahamas, where the natural life is equally wonderful, battles are being fought to protect pristine habitat from the encroachments of modern life such as unsuitable development (or development in unsuitable locations). For this first look at Bimini, I am most grateful toBimini’s Marine Protected Area Campaignfor permission to use some of their wonderful photographic archive that illustrates the vital importance of the mangroves, reefs, sea grass and pristine sea to marine life large and small. It’s worth checking out the background and surrounding context of these images to see the sort of habitat the creatures depicted prefer. This post features some of the larger species.
HAMMERHEAD SHARKS
NURSE SHARK NURSERY IN THE MANGROVES
BOTTLENOSE DOLPHINS
RAYS
A pregnant female southern stingray, seen from below
A short while back I posted aboutSPOTTED MORAYS, which people seem to enjoy. It generated requests for more forays, specifically with green morays. I gotcha – here they are, as promised… All the eels shown below, familiar to the divers who regularly encounter them and given names such as “Judy’ and “Wasabi” (my favourite), were photographed by Scuba expert Melinda Riger, whose skills with a camera are well-known. Let’s go Green…
Like all moray species, Greens like to lurk in convenient hiding places to watch the underwater world – and possible prey – go by. Here are some typical ‘lurking’ shots.
Green morays also have the unusual breathing apparatus that resemble nasal plugs
Those who recall the spotted moray post and their singular dentition arrangements that included a long sharp tooth sticking down from the upper jaw will no doubt be thinking, “are we going be shown any dental close-ups?” But of course… why would I not?
Note the cluster of teeth in the upper jaw, differing from the spotted moray
This ‘WTF?’ series started with a relatively conventional species, the REMORA. It has been getting progressively more bizarre. We moved onto an omnium gatherum of WEIRDO FISHES, then the remarkable LETTUCE SEA SLUG, and most recently the BATFISH. Time to ramp up the stakes: with many thanks to scuba expert Adam Rees for use permission for his terrific photos, I present… the FROGFISH.
The frogfish is a kind of anglerfish found in almost all tropical and subtropical oceans and seas. There are about 50 different species worldwide, covering an astonishing range of strange appearances. They generally live on the sea floor around coral or rock reefs. In size they vary from tiny to about 15 inches long – although ‘long’ is a flexible concept because they are to an extent shape-changers in height and width.
FROGFISH SUPERPOWERS YOU MAY WISH TO HAVE
INVISIBILITY CLOAK . Frogfish are masters of disguise and camouflage. This enables them to catch their prey with minimal effort and also to avoid predators. Their camouflage methods – broadly known as ‘aggressive mimicry’ – include
Ability to change colour for days or even weeks to mimic their surroundings
Getting covered in algae and other organic matter that matches their habitat or
Looking inherently like a plump rock or in some cases, plant
Fear for the life of the spider crab…
IRRESISTIBLE ATTRACTION (just like that nice Mr Grey)
A sort of frontal dorsal fin called an illicium to which is attached a
Lure called an esca which may mimic a worm, shrimp or small fish etc and which is
Retractable in many species and
Regenerates if it gets mislaid
The ‘dollop of cream’ thing is the esca. Note the characteristic large mouth
Spot the esca…
BUOYANCY CONTROL & SHAPE-SHIFTING
Most frogfish have a ‘gas bladder’ to control their buoyancy.
Some species can change shape or even inflate themselves by sucking in quantities of water in a so-called defensive ‘threat display’.
HOW DO FROGFISH REPRODUCE?
Although not conventionally attractive creatures, frogfish clearly manage to reproduce. Little is known about the techniques in the wild, but one is probably ‘with care’, especially for a male frogfish who may not survive for long if he hangs around after fertilisation has taken place. It has been noted that females tend to select far smaller males to fertilise their huge numbers of eggs, perhaps for that very reason.
FROGFISH FEEDING SKILLS – GOOD OR BAD?
When deploying the lure, potential prey that comes too close to that wide mouth stands no chance. A frogfish will strike in a fraction of a second. Frogfishes have voracious appetites for crustaceans, other fish, and even each other. I can do no better than borrow this vivid description of a feeding frogfish:
“When potential prey is first spotted, the frogfish follows it with its eyes. Then, when it approaches within roughly seven body-lengths, the frogfish begins to move its illicium in such a way that the esca mimics the motions of the animal it resembles. As the prey approaches, the frogfish slowly moves to prepare for its attack; sometimes this involves approaching the prey or “stalking” while sometimes it is simply adjusting its mouth angle. The catch itself is made by the sudden opening of the jaws, which enlarges the volume of the mouth cavity up to twelve-fold, pulling the prey into the mouth along with water. The attack can be as fast as 6 milliseconds. The water flows out through the gills, while the prey is swallowed and the oesophagus closed with a special muscle to keep the victim from escaping. In addition to expanding their mouths, frogfish can also expand their stomachs to swallow animals up to twice their size.“
HOW DO FROGFISHES GET AROUND? SWIM? WALK? CRAWL?
Frogfishes do not in fact move around a great deal. Using their camo advantages, they prefer to lie on the sea floor and wait for prey to come to them. As mentioned in the quote above, they may slowly approach prey using their pectoral and pelvic fins to “walk” along the sea bottom. They can swim using their tail fin (or in some species by simple ‘jet propulsion’ by forcing water out of their gills) but rarely do so – they don’t feed on the move, and they are adapted to the sea floor environment where they food is readily available. However their “walking” ability is limited to short distances.
DO FROGFISH HAVE OTHER COLOUR SCHEMES?
Indeed they do. In stark contrast to the camo species, some frogfishes are highlighter bright. Here are two of my favourite photos by Adam that show this clearly. I’ve no idea if these are a male and female. I suspect they are different species. I think the brown one is a striated frogfish and the other is… a yellow frogfish. Some people keep these creatures in aquaria, but apparently it is impossible to sex them, and they have to be kept on their own for everyone’s peace of mind…
FROGFISH INFOGRAPHICS
FROGFISH VIDEOS
These two videos, from Lester Knutsen and Daan Van Wijk respectively, show some of the characteristics I have written about above. Both are short and both are fascinating.
To read more about frogfishes and for some fabulous photos I highly recommend the websiteFROGFISH.CHYou can reach the main page(s) but the link seem to be broken so I have not been able to contact Teresa Zubi, whose site it is. She clearly has a sense of humour and uses a neat pair of gifs which I hope she won’t mind my using…
Credits: All main photos, Adam Rees of Scuba Works with many thanks; wiki for ‘spot the esca’, red quote & basic info; videos Lester Knutsen & Daan Van Wijk; Teresa Zubi for website & gifs; infographics, authors u/k
I’ve been neglecting the moray eels. It’s ages since I did a post about them, and it’s time to put that right. Specifically, time to take a look at Spotted Morays Gymnothorax moringa. These eels can grow up to 2 meters, and live mainly in the sub-tropical waters of the Atlantic. They are solitary creatures, most often seen with just their heads protruding from holes and fissures reefs and r0cks. They have interesting dental arrangements (see below) and their bite is one that, all things being equal, is probably best avoided… Here’s what to look for.
ADULT SPOTTED MORAYS
TOOTHSOME CRITTERS (FANGS FOR THE MEMORY…)
WICKLE BABY MORAY. MORAYKIN?
Photo credits: all amazing photos courtesy of Melinda Riger of Grand Bahama Scuba; Props to ‘Earl the Eel’ who appears in some of them!
That’s ‘Batfish’ (or strictly, Batfishes, for there are some 60 species worldwide), as in one of the weirdest, most alien underwater creatures you may ever encounter. As opposed to ‘Bait Fish’, those little silvery specimens that are so attractive to predator fish higher up the food chain – the ones fishermen might be interested in… And the Batfish has no connection at all with Bruce Wayne of Wayne Manor, Gotham City nor with his sidekick Robin.I mention this bizarre-looking and -acting creature because two have recently been seen and photographed in Abaco waters and although I’d heard of the batfish and even knew vaguely what one looked like, I was quite unprepared for the real thing. Ellen Sokol is a Captain forKiskeedee Sailing Charters which during the summer is based in the Abacos and which amongst other things gives youngsters the opportunity to snorkel and to learn about undersea life. Ellen says: “I was snorkelling when I saw this thing on the bottom. At first, I thought it was a dead bird! It wasn’t moving at all even when I touched it with my flipper. Later when I read about this fish I learned that it sits motionless and uses the long nose to attract prey. I suppose that is exactly what it was doing when I rudely interrupted it! I later researched, and found it to be a spotted batfish”. Because they had no underwater camera on board, Ellen’s son gently scooped it up in a net so they could take a quick photo of the fish before returning it. Quick thinking!The other recent sighting was posted with a photo on FB within the last 3 weeks by the excellentCRUISE ABACO.
10 OGCOCEPHALIDAE (BATFISH) FACTS TO TREASURE
There are some 60 species of batfishes worldwide
They live in warm and temperate seas, including the waters of the Bahamas
An adult batfish is 12″ – 14″ in length
Their bodies are generally lumpy, with some hard spines
Some have a long, upturned snout. Others have bright red ‘lipstick lips’
They are rubbish swimmers, and often ‘walk’ on their limb-like pectoral and pelvic fins
Most species are deep sea denizens but some (short nose, spotted) inhabit shallower water
The fleshy snout above the mouth lures prey close enough to its jaws to eat
The batfish is becoming increasingly rare worldwide, and is considered to be endangered
Only the word ‘Logcock’ (pileated woodpecker) contains the initial 4 letters of Ogcocephalidae
CAN YOU SHOW ME SOME MORE EXAMPLES OF THIS INTRIGUING FISH?
By all means. Here are some images of other batfish species – red-lipped, long nosed, short nosed – each peculiar in its own way. You’ll see their preferred, most unfishlike method for getting around.
Q. PLEASE MAY I SEE A VIDEO OF A BATFISH? A. YES. TWO.
“Heather Ashcraft found this very rare short-nosed bat fish on Eleuthera, Bahamas Sept 17 2013. It is a very strange (almost alien) looking combination of bat, frog, bird, and fish. The pelvic fins are used for walking on the ocean floor… Above the bat face is a horn (or beak)…”
“Taken at Coco Cay, Bahamas, April 29, 2014. At first we had no Idea what we were looking at… one of the weirdest things we had ever seen. Apparently they are rare. Even some of the locals had no idea what we were describing”
Batfish, Man-o-War Cay Abaco (Cheryl Marx MacKee)
Batfish, Abaco (Bob Williams August 2015)
Credits: Header image courtesy Texas Parks and Wildlife Department (Brenda Bowling); Ellen Sokol and Kiskeedee Sailing Charters; Cruise Abaco; Wiki, Barry Peters, NURP, Eric Reisch; Youtubers x 2; Petersen, Arkive, Cheryl Marx MacKee, Bob Williams and sundry magpie pickings…
BAHAMAS WHALES & DOLPHINS IN ABACO & ANDROS WATERS
The Bahamas Marine Mammal Research Organisation (BMMRO) has its HQ at Sandy Point, Abaco. We recently went out in their research boat, a RHIB, to spend an unforgettable day with Blainville’s beaked whales and bottlenose dolphins. I posted some of the dolphins HERE; and a two-part beaked whale post is a work in progress.
Male Blainville’s beaked whale with its extraordinary barnacle-encrusted teeth that protrude upwards from its lower jaw. The prominent beak is plainly visible. Sighted off the south-west point of Abaco during our second encounter with a group of these whales – the only male we saw that day
Abaco waters are ideal for marine mammals, especially off the southern shores where the walls of the Great Bahama Canyon drop vertiginously down from the shallow coastal waters to depths of up to 3 miles below. This is one of the deepest ocean canyons in the world. The area provides a rich source of food and nutrients for the whales and dolphins and many different species are regularly sighted there, from huge sperm whales to small pilot whales (including plenty of species I had never heard of before).
As the name suggests, the BMMRO’s remit extends far beyond Abaco. The researchers often spend time exploring and recording cetaceans in other Bahamian waters. For the last few weeks the team have been off Andros and have encountered quite a few target species. I have included a selection below taken within the last month to illustrate the importance of the area for a remarkable assortment of wonderful whales and dolphins.
BLAINVILLE’S BEAKED WHALE
DWARF SPERM WHALES
PANTROPICAL SPOTTED DOLPHINS
On board the research vessel, every sighting is recorded in detail – where possible by species, numbers, ages, sexes, and individual identifying characteristics. Thus ‘SW34’ may have a damaged fluke, whereas ‘RD49’ may have a long scar on its back.
PILOT WHALES
The research boat is equipped with sound devices which, when the microphone is immersed, are capable of picking up whale or dolphin sounds from a considerable distance. It’s astounding to be able to listen in ‘live’ to the wide assortment of clicks and whistles produced as the creatures communicate with each other. The recorded sound patterns are studied and can often be matched to enable an individual animal to be identified.
MELON-HEADED WHALES
RISSO’S DOLPHIN
Other work, including photography, is done underwater. Perhaps the most intriguing aspect is the collection of poop specimens, from which a great deal can be ascertained about the diet and health of an individual animal. I wrote about this task and the methods used a while ago in ‘FAMILIAR FECES‘.
I’ll be writing more about whales soon. Meanwhile, here’s a short BMMRO video of a large group of melon-headed males. At the start, you can clearly hear communication sounds between them.
Credits: Charlotte & Diane of the BMMRO for taking us out with them and for all the photos except the male Blainville’s beaked whale (mine, for once!)
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