MANGROVE DIE-BACK IN THE ABACO MARLS: THE FACTS


Mangroves, The Marls, Abaco, Bahamas (Keith Salvesen, Rolling Harbour)

MANGROVE DIE-BACK IN THE ABACO MARLS: THE FACTS

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 map HERE. You’ll find other relevant and authoritative mangrove material if you check out the BLOG menu of the website.
Abaco - The Marls

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.

Stingrays Abaco Marls 6

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.Mangrove Die-back 1 (Abaco Scientist : Ryann Rossi)

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 lesions nearly 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.

Mangrove Die-back 2 (Abaco Scientist : Ryann Rossi) jpg

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.

Mangrove Die-back 3 (Abaco Scientist : Ryann Rossi) jpg

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.

By Ryann Rossi|August 26th, 2015|Disease, fungus, Insects, Mangroves and Creeks, The Marls
All pics below taken while fishing on the Marls except Melinda’s shark (I’ve never got a good one)
Hawksbill Turtle, Abaco Marls (Keith Salvesen)Bonefish Gotcha - Abaco Marls (Keith Salvesen)Shark 4 ©Melinda Riger @ G B Scuba copyOsprey - Abaco Marls 1 Reddish Egret (White Morph), Abaco MarlsRoyal Tern, Abaco, Bahamas (Marls) 3Willet, The Marls, AbacoSouthern Stingray, Abaco Marls (Keith Salvesen 4)
FRIENDS OF THE ENVIRONMENT has also included an article on die-back by Ryann in its latest Newsletter:

Mangrove Die Off on Abaco by Ryann Rossi, NCSU

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.

3 men on a skiff, Abaco Marls (Keith Salvesen : Rolling Harbour)

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.

Mangroves, Abaco Marls (Keith Salvesen)

Credits: Source material Ryann Rossi; Abaco Scientist; all photos © Keith Salvesen @ Rolling Harbour except those by Ryann / ABSCI in the main article and Melinda Riger’s cool shark

BAHAMAS MANATEE MAGIC ON ABACO & BEYOND


Gina the Manatee & her calf (BMMRO)

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 page HERE.

     Georgie’s epic trip (Sept 12) continued to Cherokee Sound; and Randy’s ‘pursuit’ (Sept 14)Georgie Manatee's direct route to Abaco       Randy's the Manatee's trip Berry Is. to Abaco copy

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

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 to http://www.bahamaswhales.org/sightings/index.html NB 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”

Bahamas Manatee Location Map - Aug 2015 (Felice Leanne Knowles)

Gina the Manatee, Casuarina, Abaco (BMMRO / FLK)

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 the Manatee, Hope Town, Abaco (BMMRO / FLK)

Randy (sub-adult male) Last sighted in Hope Town August 12th, 2015 Key feature – triangle cut on right side of paddle

Manatees, Hope Town, Abaco (BMMRO / FLK)

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 the Manatee with her calf, Spanish Wells Bahamas (BMMRO / FLK)

Gina’s Calf Last seen August 6th, Spanish Wells Key feature – none yet, just really tiny!

Blackbeard the manatee, Lyford Cay, New Providence (BMMRO / FLK)

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 the Bahamas Manatee, Great Harbour Cay Marina, Berry Is. (BMMRO / FLK)

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. the manatee, Great Harbour Cay Marina, Berry Islands (BMMRO / FLK)

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 the Manatee, Hawks Nest Marine, Cat Island (BMMRO/ FLK)

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 Manatee, West Grand Bahama (BMMRO /FLK)

Unknown adult, West Grand Bahama – Key feature: too distant!

Manatee Awareness Poster jpg

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.

The Travelling Mantee’s Favourite Song

RELATED LINKS

BAHAMA MANATEE CLUB

REPORT MANATEE SIGHTINGS

BMMRO

ROLLING HARBOUR MANATEES

MANATEE CONSERVATION

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…)

Manatee Logo (Savethemanatee.org)

WHALE TALES FROM ABACO (1): BLAINVILLE’S BEAKED WHALES


Blainville's Beaked Whales, Abaco (1) (Keith Salvesen)

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…Blainville's Beaked Whales, Abaco (1) (Keith Salvesen)

A Blainville’s beaked whale noses towards the research vesselBlainville's Beaked Whales, Abaco (1) (Keith Salvesen)

The Blainville’s beaked whale (Mesoplodon densirostris) is also known slightly less politely as the dense-beaked whale.  It is named for the 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 surfaceBlainville's Beaked Whales, Abaco (1) (Keith Salvesen)

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.Blainville's Beaked Whales, Abaco (1) (Keith Salvesen)

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.

Blainville's Beaked Whales, Abaco (1) (Keith Salvesen)

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.

Whale showing healed circular wounds caused by COOKIECUTTER SHARKSBlainville's Beaked Whales, Abaco (1) (Keith Salvesen)

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.

Cetacea_range_map_Blainvilles_Beaked_WhaleBlainville's Beaked Whales, Abaco (1) (Keith Salvesen)

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..Blainville's Beaked Whales, Abaco (1) (Keith Salvesen)

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 scoopBlainville's Beaked Whales, Abaco (1) 11 16.46.13

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 diveBlainville's Beaked Whales, Abaco (1) (Keith Salvesen)

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, AbacoBMMRO Research Boat, Sandy Point, Abaco (Keith Salvesen) BMMRO HQ, Sandy Point, Abaco (Keith Salvesen)

Credits: All photos RH; Charlotte & Diane for a brilliant day out; Mr Blainville for a brilliant whale

220px-Henri_Marie_Ducrotay_de_Blainville

CARIBBEAN REEF SQUID: SUPERPOWERS & SEX LIVES REVEALED


Squid ©Melinda Riger @ Grand Bahama Scuba

CARIBBEAN REEF SQUID: SUPERPOWERS & SEX LIVES REVEALED

The Caribbean reef squid Sepioteuthis sepioidea is a small squid species of the Caribbean Sea and the Floridian coast. Its fins extend nearly the whole length of the body and undulate rapidly as it swims. Recently, it has been discovered that this squid is capable of brief flight out of the water.Squid ©Melinda Riger @ Grand Bahama Scuba

Reef squid tend to form small shoals in and around reefs. It is by far the most common squid species in its range, and can be sighted both close to the shore and quite near the surface (although that increases the risk of predation by seabirds).

A silvery squid swimming just below the surfaceCaribbean_reef_squid (Ed Brown)

Squid are voracious eaters, dragging their prey to their mouths and using a beak to cut it up. Their target species are small fish, molluscs and crustaceans. They have a ‘raspy tongue’ known as a radula which further breaks up the food for easy consumption.

Squid at Fowl Cay Marine Preserve, AbacoSquid Fowl Cay, Abaco Ellen Sokol, Kiskeedee Sailing Charters

SQUID SUPERPOWERS (SUPERCOOL)

  • Squid can change colour, texture and shape
  • This enviable power is used defensively as camouflage or to appear larger if threatened
  • It is also used in courtship rituals, something that humans would find most disconcerting
  • Colour patterns are also used for routine squid-to-squid communication AND GET THIS:
  • A squid can send a message to another on one side, and a different one to a squid on the other

Squid © Melinda Riger @ Grand Bahama Scuba copy

SQUID SEX (1) “ROMANCING THE SQUID”

  • A male will gently stroke a female with his tentacles
  • The female will (most likely) flash an ‘alarm’ pattern
  • The male soothes her (don’t try this at home, guys) by blowing and jetting water at her
  • If he’s not getting on well, he’ll move off and repeat the routine until she sees his good points
  • However this on / off courtship can last for hours until at last he succeeds by…
  • …attaching a sticky packet of sperm onto the female’s body (romance is not dead)
  • She reaches for it and moves it to her “seminal receptacle”
  • Meanwhile he stays close, emitting a pulsing pattern, as well he might after all that
  • She then finds a safe place to lay her eggs. Job done.Two_Caribbean_Reef_Squid,(Clark Anderson)

SQUID SEX (2) IT ALL ENDS BADLY

  • As soon the female squid has laid her eggs, she dies at once
  • The male squid live a bit longer, and may have other packets to stick – then he dies too
  • It’s all horribly reminiscent of Romeo and Juliet. Without the balcony scene.Sepioteuthis sepioidea Caribbean Reef Squid (Nick Hobgood)

USES OF SQUID ON ABACO

Squid are prolific in the seas around Abaco, which is fortunate because they form a large part of the diet of some whale species, particularly the Blainville’s Beaked Whales that are commonly found in Abaco waters. I have a post on these magnificent creatures in preparation right now, and am in the process of sorting out suitable photos from a large number taken during a research expedition in March. 

More Squid at Fowl Cay Marine Preserve, AbacoSquid School, Fowl Cay, Abaco Ellen Sokol, Kiskeedee Sailing Charters

Credits: As ever (for underwater pics) Melinda Riger of Grand Bahama Scuba; also Ellen Sokol of Kiskeedee Sailing Charters, who kindly sent me the Fowl Cay photos; also Ed Brown, Clark Anderson and Nick Hobgood for ‘open-sourcing’ their great images

WTF? (WHAT’S THAT FISH?) (5): THE FROGFISH


Frogfish (Adam Rees, Scuba Works)

WTF? (WHAT’S THAT FISH?) (5): THE FROGFISH

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.

Frogfish (Adam Rees, Scuba Works)

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 (Adam Rees Scuba Works)

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 crabFrogfish (Adam Rees, Scuba Works)

  • 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 mouthFrogfish (Adam Rees, Scuba Works)

Spot the escaFrogfish (wiki)

  • 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’.

frogfish-black

Frogfish (Adam Rees Scuba Works) Frogfish (Adam Rees Scuba Works)

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 (Adam Rees, Scuba Works)

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.

images

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.

frogfish-anglerfisch

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 (Adam Rees Scuba Works) Frogfish (Adam Rees Scuba Works)

FROGFISH INFOGRAPHICS

frogfishFrogfish Infographic 'Monsters of the Deep'

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 website FROGFISH.CH You 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

Frogfish Tee Shirt

FORAYS WITH MORAYS (2): SPOTTED IN THE BAHAMAS…


Spotted Moray Eel, Bahamas (Melinda Riger Grand Bahama Scuba)

FORAYS WITH MORAYS (2): SPOTTED IN THE BAHAMAS…

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 MORAYSSpotted Moray Eel, Bahamas (Melinda Riger Grand Bahama Scuba) Spotted Moray Eel, Bahamas (Melinda Riger Grand Bahama Scuba) Spotted Moray Eel, Bahamas (Melinda Riger Grand Bahama Scuba) Spotted Moray Eel, Bahamas (Melinda Riger Grand Bahama Scuba)

TOOTHSOME CRITTERS (FANGS FOR THE MEMORY…)Spotted Moray Eel, Bahamas (Melinda Riger Grand Bahama Scuba) Spotted Moray Eel, Bahamas (Melinda Riger Grand Bahama Scuba) Spotted Moray Eel, Bahamas (Melinda Riger Grand Bahama Scuba)

WICKLE BABY MORAY. MORAYKIN?BABY Spotted Moray Eel, Bahamas (Melinda Riger Grand Bahama Scuba)

Photo credits: all amazing photos courtesy of Melinda Riger of Grand Bahama Scuba; Props to ‘Earl the Eel’ who appears in some of them!

BAHAMAS WHALES & DOLPHINS IN ABACO & ANDROS WATERS


Melon-headed Whale breaching - BMMRO copy

Melon-headed Whale breaching – BMMRO

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 dayBlainville's Beaked Whale KS 1

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). 

Great Bahama Canyon Map edit

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 WHALEBlainville's Beaked Whale copy

DWARF SPERM WHALESDwarf Sperm Whales - BMMRO copy

PANTROPICAL SPOTTED DOLPHINSPantropical Spotted Dolphin - BMMRO Pantropical Spotted Dolphin leap - BMMRO copy

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 WHALESPilot Whale - BMMROPilot Whales - BMMRO copyPilot Whales 2 - BMMRO

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 WHALESMelon-headed Whales - BMMRO Melon-headed Whale - BMMRO

RISSO’S DOLPHINRisso's Dolphin - BMMRO copy

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 inFAMILIAR 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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