ENDANGERED SPECIES, ABACO (3): NASSAU GROUPER


Nassau Grouper (Melinda Riger / G B Scuba)

ENDANGERED SPECIES, ABACO (3): NASSAU GROUPER

The Nassau grouper Epinephelus striatus is one of a number of grouper species found in Bahamian waters. Of these, only the Nassau grouper is on the IUCN Red List, as Critically Endangered. When I last wrote about them they were in the lesser category ‘Threatened’.

Nassau Grouper (Melinda Riger / G B Scuba

In order to sustain a viable population, it is vital to maintain numbers and preferably to increase them year on year. Once it became clear that year-round commercial overfishing was a prime component of the steep decline in the population, a 3-month closed season during the breeding period was imposed. This has ensured that at the most critical time in the lifecycle of the species, the groupers are left alone to breed in peace and to perpetuate their species.

Nassau Grouper (Melinda Riger / G B Scuba)

The closed season operates from December to February to maximise the chances of breeding success. As with some other fish species, reproduction occurs around the full moon. The fish gather at spawning sites and the process is at its height around sunset.

Nassau Grouper (Melinda Rogers / Dive Abaco)

10 CONVENIENTLY COLLECTED NASSAU GROUPER FACTS

  • An adult can grow to more than a metre long, and weigh 25 kg
  • They tend to be solitary daytime feeders, eating small fish & crustaceans
  • Their large mouths are use to ‘inhale’ or suck in prey
  • The colouring of an individual can vary from red to brown
  • These fish have little black spots around the eyes (I’ve no idea why).
  • Their habitat is in the vicinity of coral reefs, from shallows to 100 m deep
  • Spawning mainly occurs in Dec & Jan during a full moon
  • Large numbers gather in a single location to mate in a mass spawning
  • These groupers are slow breeders, which compounds the overfishing problem
  • They are easy mass targets at spawning time; hence the need for a closed season

Nassau Grouper (Melinda Riger / G B Scuba)

A Nassau Grouper glumly contemplates the possibility of extinctionNassau Grouper (Melinda Riger / G B Scuba)

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Nassau Grouper (Melinda Rogers / Dive Abaco)

Credits: Melinda Riger / Grand Bahamas Scuba (1, 2, 3, 5, 6); Melinda Rogers / Dive Abaco (4, 7)

SEA URCHINS: PICTURE PERFECT ABACO (11)


SEA URCHINS: PICTURE PERFECT ABACO (11)

Sea Urchin, Abaco, Bahamas (Melinda Rogers / Dive Abaco)

As every swimmer knows, or eventually finds out the hard way, it’s not only Blue Suede Shoes that should not be stepped on. But however painful the consequences of a misstep, it’s hard not to find some beauty in an urchin living in a thriving reef environment. The wonderful anatomical diagram by Alex Ries shows everything you could conceivably want to know about one of nature’s most proficient foot-stabbers (if only all such diagrams were presented so simply and clearly).

Sea urchin anatomy (Alex Ries)

The internal organs depicted resemble a bad trip in the bowels of a vacuum cleaner; or (narrow your eyes) an experimental painting from one of the less successful schools of early c20 modern art, soon to be swept aside by Cubism. Note that the mouth is located where you might expect to find the opposite end, and vice versa.

I photographed the urchin test (skeleton) below at Delphi. It was large and almost entirely undamaged (very rare in my experience). The bright faintly greenish white is set off by the palest of pinks. Whatever your view of how creatures came to exist, imagine the creation or evolution of calcium carbonate into a small symmetrical structure as beautiful, detailed and complex as this. If you are short of a lockdown recreation, maybe try to draw it.

Sea Urchin Test / Skeleton, Abaco Bahamas (Keith Salvesen / Rolling Harbour Abaco)

Photo credits: #1 Melinda Rogers / Dive Abaco; #2 Anatomy Diagram, Alex Reis (5 stars for making it available free on Wikimedia); #3 Keith Salvesen / Rolling Harbour Abaco

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


Frogfish (Adam Rees / Scuba Works)

The Astoundingly 5* Strange Frogfish (Adam Rees / Scuba Works)

WTF? (WHAT’S THAT FISH?)

A COMPENDIUM OF SUBSURFACE WEIRDNESS

A SERIES OF 15 OF THE STRANGEST SEA CREATURES IN BAHAMAS WATERS

INTRODUCTION

WTF? stands for ‘What’s That Fish’? But it might also be your exclamation when you come across one of these creatures. The WTF? series highlights some of the unusual, curious, weird and downright extraordinary fishes that inhabit the waters of the northern Bahamas. Some represent local forms of a species found elsewhere in the world; others are in their own evolutionary cul-de-sac. Just as I think I have seen it all, so another oddity crops up somewhere that demands inclusion. 

The WTF? series, put together over several years, is intended to be the most direct route to an underwater menagerie of piscine strangeness, with some great photos to whet your appetite to learn more about these fascinating denizens of the ocean. 

1. THE FROGFISH

* CLICK ON THIS TITLE TO BE TRANSPORTED TO THE STRANGE WORLD OF THE FROGFISH *

Frogfish (Adam Rees, Scuba Works)Credits are given in the individual articles. Thanks to all those that have provide the photos, without which this type of illustrated, unscientifically scientific poke around in the ocean depths would not be possible.

WTF? (WHAT’S THAT FISH?) 17: YELLOWHEAD JAWFISH


Yellowhead Jawfish (Melinda Riger / Grand Bahama Scuba)

WTF? (WHAT’S THAT FISH?) 17: YELLOWHEAD JAWFISH

It’s been a little time since I added to the WTF? series, in which some of the more outlandish reef denizens come under close scrutiny. Jawfishes (Opistognathidae) come into this category, not least because of their interesting ways with their eggs. Also, they tend to stick upright out of the substrate, which is not especially fishy behaviour.

Yellowhead Jawfish (Melinda Riger / Grand Bahama Scuba)

More than 50 species of jawfish are found around the world. In the Bahamas, you are most likely to encounter the Yellowhead (or Yellow-headed) variety. And if you think they look slightly… primitive, that’s because they are. In fact, their forebears (forefishes?) originated in prehistoric times, specifically the Miocene era (a lot of million years ago, I didn’t count exactly).

Yellowhead Jawfish (Melinda Riger / Grand Bahama Scuba)

These rather extraordinary little fish superficially resemble certain types of BLENNY. Their modus operandi is to burrow down into sandy, gravelly or other loose substrate. They do so by cramming their mouths with sand and spitting it out to one side. By this means they form a tunnel of sorts in which they can live, and from which they can emerge, or half-emerge and take a look around them. As they do so, they hoover up passing food, mostly plankton and suchlike.

Yellowhead Jawfish (Virginia Cooper / Grand Bahama Scuba)

If something looks threatening while they are feeding or having a look around, they can simply duck down into their burrow for safety. They guard their patch against rivals, and behave ‘territorially’ in the jawfish community. One method is to ingest and and then eject sand or gravel at a would-be intruder.

Yellowhead Jawfish (Michael Wolf Wiki))

YES, BUT WHERE IS THE REAL ‘WTF?’ FACTOR HERE?

Good question. With a good and original answer. These little creatures are so-called MOUTHBROODERS‘, meaning that they carry their eggs in their mouths. Depending on the species, females, males or even both parents (don’t try this at home) will do this at or after fertilisation. In effect the eggs are safely incubated until they hatch as fry. Then they are on their own.

Yellowhead Jawfish (Melinda Riger / Grand Bahama Scuba)

ARE THERE ANY DRAWBACKS TO THIS UNUSUAL GESTATION METHOD?

Apart from accidentally swallowing the occasional potential junior, the eggs need aeration from time to time. This is achieved by expelling the eggs from the mouth, and quickly sucking them back in again. Try this very short video to see this rather improbable behaviour in action. It’s only 8 seconds blink and you’ll miss the action. The eggs hatch into fry in 8 – 10 days, after which both parents can relax. Until the next time.

Yellowhead Jawfish (Melinda Riger / Grand Bahama Scuba)
Photo Credits: all images from Melinda Riger / Grand Bahama Scuba except (4) Virginia Cooper / GBS; (5) Michael Wolf / Wikimedia; video, Alan Keller. Research: magpie picking, not excluding yet not limited to Wiki…
Yellowhead Jawfish (Melinda Riger / Grand Bahama Scuba)

PURPLE VASE SPONGES: BAHAMAS REEF ORNAMENTS


Purple Vase Sponge, Bahamas (Melinda Riger / G B Scuba)

PURPLE VASE SPONGES: BAHAMAS REEF ORNAMENTS

The Purple Vase is an unmistakeable sponge, a colourful reef creature (for they are animals, of course) that stands even out amongst the bright corals that surround it. And like corals, sponges are vulnerable to all the usual threats (mainly human-generated).

Purple Vase Sponge, Bahamas (Melinda Riger / G B Scuba)

Catch them while you can in the clear waters of the Bahamas while stocks last. I say this because as study after study concludes, the prospects of reef-mageddon get closer each year. When the corals die off, so in all probability will the sponges and anemones…

Purple Vase Sponge, Bahamas (Melinda Riger / G B Scuba)

After such a depressing intro, let’s move on to take a positive look at the purple vase sponge. As with all sponges, once a newborn sponge is wafted by the current to a place on the reef, it takes root there throughout its life. There, these attractive sponges exist by filtering the water that surrounds them, separating out plankton to feed on. Static filter-feeders, if you will.

Purple Vase Sponge, Bahamas (Melinda Riger / G B Scuba)

You’ll notice that in some of the photographs, the sponges have guests. These are BRITTLE STARS, and they are often found on – and indeed in – purple vases. This is a form of symbiotic relationship known as commensalism, in which one species benefits and the other is neither benefitted nor harmed. The brittle star gains a shelter and a safe base for feeding; the vase gets a harmless companion. Small fishes benefit from the vases in a similar way.

Purple Vase Sponge, Bahamas (Melinda Riger / G B Scuba)

Besides the impact of damaging human interventions (which may be permanent), extreme weather events also affect reef life and the static inhabitants adversely. Storms and hurricanes can cause localised havoc, but the damage is not necessarily permanent. The reef can in time repopulate naturally and flourish again. Humans can even promote this recovery. The photograph above shows a purple vase sponge that was detached from the reef by Hurricane Matthew in October 2016. Melinda Riger in effect replanted it on the reef and it reattached itself and grew. In due course it even acquired its brittle star occupant. 

Purple Vase Sponge, Bahamas (Melinda Riger / G B Scuba)

*JIMI AND ‘PURPLE VASE’ – A VOLUNTARY MUSICAL DIGRESSION

In an interview with NME Hendrix is reported to have said that Purple Haze “was about a dream I had that I was walking under the sea.” Originally the song was intended to be ‘Purple Vase’, and reflect the psychedelic experience of life on a coral reef. Realising he was getting bogged down by sub-aquatic imagery (he was a non-swimmer), he toked for a while and then ‘Purple Haze’ emerged almost fully formed. He was always far happier kissing the sky than wandering about under the waves. Most covers of the song are pale imitations of the original, but here’s a rather unusual take that succeeds by trying a different approach…

Credits: Melinda Riger / Grand Bahama Scuba for all great photos; magpie pickings for bits and pieces, with a shout-out to ‘Critter Squad’ for its informative site aimed at kids. And amateur grown-ups can benefit too… commensalism in humans; Friend ‘n’ Fellow audio

Purple Vase Sponge, Bahamas (Melinda Riger / G B Scuba)

REAL THREATS, ALARMING PHOTOS: OSPREYS IN PERIL


THE THREATS ARE REAL AND THESE PHOTOS SHOULD ALARM YOU!

I rarely – in fact almost never – lift an entire article from elsewhere and plant it wholesale here. I make an exception today. Ben’s article is so relevant, so well put together, so compelling and so scary in its implications that it can’t be ignored. No individual is to blame. We all are. Mankind generally – and pretty much all of it in my lifetime. Walk any beach in Abaco, however secluded. There it all is, under your feet. Find a dead seabird? Chances are it will have significant amounts of plastic inside it. Seen those wretched images of turtles with plastic bags hanging out of their mouths? It’s going to get worse…

Now see how things are with our bird partners in New Jersey and their beautiful ospreys.

DOCUMENTING THE PRESENCE OF PLASTICS IN OSPREY NESTS

by Ben Wurst, Habitat Program Manager http://www.conservewildlifenj.org

U.S. Coast Guard assists NJ Fish & Wildlife with recovering an entangled osprey on a channel marker in Cape May Harbor, Summer 2018. photo by Kathy Clark/ENSP

BEN WURST WRITES As I work to finalise data from this summer’s osprey surveys, I wanted to look back and highlight an important observation: more plastic is being found and recovered from active osprey nests. I guess it’s no surprise when you hear that “18 billion pounds of plastic waste flows into the oceans every year from coastal regions.

The alarming trend is also becoming more deadly for ospreys, and other marine life who ingest it. While it might not seem like a lot, this year a total of four young ospreys were found dead from being entangled in plastic. In my books, one dead osprey is too many! This is not a natural cause of death! Luckily, there were several other entanglements that were prevented, but this trend is likely to get worse. We hope that these photos will help you to do all that you can to help prevent it from becoming a growing threat to ospreys and other marine wildlife, who might ingest plastics.

Ospreys are an indicator species. We can’t stress that enough. The health of their population can be directly linked to their surrounding environment. When we poisoned the land with persistent pesticides, the ospreys told us. When we overfished menhaden, the primary prey item of ospreys during the nestling period, the ospreys told us. When we use and discard plastics with no care, the ospreys will tell us…

From the land, where they collect nesting material, to the water, where they forage for prey. The growing presence of plastics on land and in water, highlights need to restrict single use plastics, balloon releases, and for any single use plastic fee to directly fund cleanups of plastic waste. It’s no surprise that ospreys use plastic items in their nests. It’s now become a common resource for them which looks similar to natural nesting material and collects in the same areas where they gather nest material. The more plastics in the world means more plastics in osprey nests!

When out on the marsh or on the beach, if you look around you’ll find plastic. According to the Clean Ocean Action 2017 Beach Sweep report (for the first time since the sweeps began in 1985) 84.45% of items collected on the beach were plastic (including foam). Another alarming trend is the growth in balloons found on the beach. In 2017, a total of 4,137 were found. Next time your down the shore, try to determine the difference between a white single use plastic bag and bleached sea lettuce, or white balloon ribbon and bleached eelgrass… Please don’t ever release balloons!

The most deadly piece of plastic litter for ospreys this year was monofilament or fishing line. The four ospreys that were found dead died from being entangled in monofilament. Fishing line is typically brought into a nest while attached to a stick or branch. It then becomes part of the nest and can easily get wrapped around a nestlings leg, foot or wing. This is not an isolated event. It happens throughout the range of ospreys (here are just a few that made the news). Please dispose of your fishing line appropriately! Single strand monofilament can even be collected and mailed to Berkley (a manufacturer of fishing line) for recycling/reuse!

Sadly, this is only the beginning. Plastics don’t biodegrade and this is becoming a chronic issue. Almost all osprey nests in New Jersey contain some type of plastic (next year we are planning to add data fields to our nest survey datasheets to keep better track of how many nests contain plastic). It’s still too early to see the effects of plastics as as they bioaccumulate in the food chain of predatory animals, like the osprey, but we hope that we can prevent this. We can all help by reducing our use of single use plastics. Here are some simple ways that you can help:

  1. Never release balloons! Talk to your friends/family about where balloons actually wind up.
  2. Reduce your dependence/consumption of single use plastics: bring your own reusable bag, water bottle, and coffee cups. Buy beverages in glass or aluminum containers. When eating out or getting take out, ask for no single use plastic items and/or bring your own container for leftovers. Support a Surfrider Foundation Ocean Friendly Restaurant!
  3. Reuse or repurpose things that can’t be recycled. Opt into free recycling programs for hard to recycle items through Terracycle, a NJ based waste reduction company.
  4. Pick up plastic litter. Participate in coastal cleanups (the next COA Beach Sweep is on 10/20!). Dispose of trash responsibly.

Thank you to all of our volunteers, especially our Osprey Project Banders, and those who’ve helped to reduce plastic debris in our environment!

CREDIT: Ben Wurst and his team at http://www.conservewildlifenj.org for the article. Photos as credited in the text. We are Bahamas partners of this organisation in Piping Plover research on the shores of Abaco and our annual Abaco Piping Watch

https://www.facebook.com/Abaco.Piping.Plovers

MANATEES IN THE BAHAMAS? WE GOTTEM!


MANATEES IN THE BAHAMAS? WE GOTTEM!

Not so long ago, most people had no idea that the waters of the Bahamas in general – and Abaco in particular – contained a small population of these curious, gentle, trusting creatures. When I first wrote about them and their adventures, there was surprise – maybe disbelief. A few years later, all that has changed thanks to the BMMRO and an outreach program that raised awareness – and consequently the sighting and reporting – of manatees. They are now widely recognised as they nose their way round harbours, docks and landing stages – and quite rightly they still excite delight and a degree of wonderment. 

You can find out more – lots more – about Bahamas manatees on my page HERE. I have a post in progress about recent manatee developments with a rescue one but alas I have found I have already run out of week through some kind of bizarre time / space continuum dislocation (specifically, flagrant time-mismanagement). So I am posting a few adorable images to be going on with. 

And remember, if you happen to see one, please do report it to the BMMRO or let me know. Useful data includes date, location and a description if possible of any damage – notches and nicks – to the paddle (= tail). It’s a good method for ID. Photos a bonus.  Every sighting adds to the database of knowledge about these strangest of creatures of the Bahamian seas. And you’ll be pleased to know that they are undoubtedly managing to breed in the Bahamas: there are baby manatees to prove it…

All photos: BMMRO