#great southern reef

[sitting-on-me-bum]

“Underwater Fireworks”

Shot in Mornington Peninsula, Australia.

“In the shallow waters of Naarm (Port Phillip Bay), sparse colonies of Tubular Hydroids poke their heads out of the sand in cold, shallow water. There are hundreds of individuals, but at just 4cm or so tall it's easy to dismiss these tiny animals which are endemic to the Great Southern Reef of Australia. Each individual here is either male or female and extend their outer tentacles to catch passing plankton.”

by Imogen Manins

Ocean Art 2023

[cogumellow]

great mayan mesoamerican barrier reef // caye caulker, belize // 2016 // ©

[nixieofthenorth]

@heronisland by  @theblondenomads

[astro-kitsun3]

Ocean fandom is dying pls reblog

People who selected the first 2 options please put in the tags whats the most famous lake or ocean you've swam in.Please reblog i want a bigger survey size

[fira54funko]

Christmas Time At Bondi Beach.

[goggledoddle]

[geographikworld]

THREE ICONIC MUST-SEE WONDERS

The natural world is full of wonders that have captivated humans for centuries. From the towering mountains to the deep blue oceans, the Earth is a treasure trove of natural beauty and awe-inspiring phenomena. Its awesomeness can also be found in the starry night sky, exhibiting a rich uniqueness of twinkling stars. Some of these magnificent wonders are seen below:

THE GRAND CANYON

This is one of the most historical natural wonders of the world. The Grand Canyon is situated in Arizona, USA. A lot of us must have heard of the Grand Canyon, with some wondering what it is. Well, let’s start by defining a Canyon. A canyon is a deep narrow valley with steep sides. It is usually accompanied by a river flowing through it. Now that we’ve gotten that cleared up, you’ll probably be wondering why it’s called the Grand Canyon. It is called the Grand Canyon because of its immense size and grandeur.

BRIEF HISTORY: The name "Grand Canyon" was coined by a one-armed civil veteran, John Wesley Powell in 1871. The Grand Canyon was formed as a result of tectonic activities. It was carved out millions of ago by ....

To continue reading, clickhttps://geographikworld.wordpress.com/2023/10/22/wonders-of-the-natural-world/

[beni75]

Photos and texts: @thomaspeschak

1-. A curious gray whale exhales almost directly into my camera

2-. A curious juvenile gray whale vigorously exhales and speeds past my camera in Mexico's San Ignacio Lagoon

3-. A Humpback whales breaches in the North Pacific Ocean off Canada's Great Bear Rainforest

4-. A dusky shark charges through a baitball of sardines

5-. y 6-. A whale sharks swins in shallow water in La Paz Bay, Baja California Sur

7-. A reef manta ray feeds on a plankton patch by barrel rolling over and over again in the same spot, not unlike a puppy chasings its own tail

8-. A reef manta ray feeds along the drop off at D'Arros Island an St. Joseph Atoll. Seychelles

9-. African peguins

10-. A endemic Socotra cormorant comes in to land on a roosting rock deep within the Fjords of Oman's Musandam Peninsula (2012)

11-. African peguins shelter and nest in decaying building long abandoned b the guano industry on Namibia's Halifax Island

12-. At Aldabra atoll green sea turtles often rest for hours on the sandy seabed between coral outcrops

13-. Blacktip reef sharks inspect the hull of our boat on Aldabra's tidal flats. Seychelles

14-. Blacktip reef sharks patrol the drop off where D'Arros Island's coral reef descendes into deeper water

15-. Cape fur seals surf Altantic swell in the Table Mountain Marine Protected Area

16-. Cape Gannet colony on Bird island bathed by lightening and the beam of the lighthouse

17-. The hunt begins at dusk and continuous deep into the night

18-. A curious gray whale swins upside down beneath our boat in Mexico's San Ignacio Lagoon

19-. A venomous lionfish hunts baitfish in Mozambique's Ponta do Ouro marine reserve, by @thomaspeschak

20-. A salmon leaps high into the air to clear a raging waterfall

21-. A wild rocky point just out into the North Pacific Ocean

22-. A large potato grouper hunts amongst schools of baitfish that seasonally drape southern Mozambique's reefs

23-. Dolphins of Indo pacific

[fishenjoyer1]

Fish of the Day

Today's fish of the day is the Southern blue ring octopus!

The Southern blue ring octopus, also known by scientific name Hapalochlaena maculosa, is well known for how venomous they are, and the vivid colorations that warn of it! The Southern blue ring octopus is one of the four species of blue ring octopi on this earth, the Southern blue ring octopus in particular is the only lesser blue ring octopi, as opposed to the other greater octopi, which are smaller in size but have far larger blue rings when threatened. Despite the differences between the Southern blue ring and the other, greater blue ring, they all live in the same general area. With the entirety of their genus spread out across the Eastern Pacific and Indian oceans, the Southern blue ring is no different, living along the Southern coast of Australia. In this environment, the octopus lives and hides within the crevasses and cracks of the rocky Australian reef.

Camouflage is very important to blue ring octopi, and this is the same thing that allows them the bright colors to warn off predators. Like many other species of cephalopods, blue ring octopi take advantage of dermal chromatophore cells, which respond to stimuli to create different colors on the skin of the animal. When threatened, the octopus will make an average of 60 bright blue rings across its form, taking as little of a third of a second. This is done by the relaxing and tensing of muscles around the shape of the ring. In greater blue ring octopi this muscle contraction also has layers of iridophores light reflectors, allowing for the blue marks to be projected further in the water. These are the only warning of the great venom these animals contain, tetrodotoxin, a neurotoxin which binds to voltage-gated sodium channels, preventing action signals from the brain to be transmitted to the body. This is because the body uses many cells which contain a certain voltage to them, and when sodium enters the cell in large amounts (as happens anytime you voluntarily move) when the voltage in the cell rises to the correct level, it triggers for the sodium channels to open in the cell next to it. This is how signals travel in the body, and how tetrodotoxin paralyzes by binding the chanels. We still don't fully understand how the poisoning works fully, as this toxin is stored in a small salivary gland in the octopus and is present in the bloodstream, this is either injected into the water or transmitted via bite. At this time there is no antivenom, but it is relatively easy to not be injured by this squid! So long as you leave them alone, they do not attack!

With all the coolest features of this animal covered, let's discuss the more mundane things. The diet of the Southern blue ring is made up of various curseceans and small fish, many of which they can hunt when the greater blue ring can not. This is because the Southern blue ring is the largest blue ring, with a whopping size of 5cm long mantle and 20cm arm-arm, a full 5-10cm larger than all other blue rings! Hunting is done by releasing the venom as a mist into the water, paralyzing prey before eating it. Their lifespan is incredibly short, lasting only 7 months on average, and mating only once in their lifetimes. The first 6 weeks of their lives will be spent growing rapidly, already nekton, as unlike most invertebrates blue rings have no planktonic stage. After these 6 weeks the blue rings can begin appearing when threatened, but the venomous trait is there from birth even without the rings presence. Mating will begin sometime with 3-5 months, and females will collect and store sperm from several partners, later choosing which male she will fertilize her eggs with. Then, there is a two month long period where she carries the eggs with her constantly, spending most of her time hiding, and moving only with 2 tentacles across the sea bed. Once these eggs hatch, the mother will pass away, leaving only her children behind to begin the cycle anew.

That's the Southern blue ring octopus, everybody! Have a wonderful day!

[mindblowingscience]

At a time when marine life is disappearing from the world's oceans, researchers are celebrating the discovery of a new species of coral reef fish in the southern waters of the Great Barrier Reef. Named the Lady Elliot Shrimp Goby, the previously unknown fish was found as part of a University of the Sunshine Coast-led project that is mapping the changing biodiversity on and around Lady Elliot Island, a tiny coral cay at the southern end of the Great Barrier Reef.

Continue Reading.

[uncharismatic-fauna]

Taming the Tiger Shark

The tiger shark (Galeocerdo cuvier) is a common sight for divers, fishermen, and tourists in the tropical waters of the Atlantic and Pacific oceans. They are often found around sea grass fields or coral reefs, and tend to prefer warm, shallower waters near the coastline or surrounding atolls and islands. The northern end of their range extends up to the northern borders of the United States and China, while their southern range reaches down to Brazil, Madagascar, and the eastern coast of Australia.

While they're slightly smaller than great whites, G. cuvier is still one of the largest carnivores in the ocean. Adults can grow up to 4.7 m (15 ft 5 in) long and weigh between 300 and 900 kg (700 and 2,000 lb). Females tend to be larger than males, but the two sexes are otherwise indistinguishable. Individuals are typically bluish gray or green, with a white or light yellow underbelly; this provides them with camouflage, as fish swimming overhead or below are unable to pick out the shark's silhouette against the dark or light background, respectively.

As an apex predator, G. cuvier has few predators of its own. Juvenile tiger sharks will often fall prey to other sharks, including adults of their own species. Orcas are also occasionally known to prey on tiger sharks, but these occurrences are rare. In their own food chain, G. cuvier has a large appetite and will eat almost anything. Coral reef fish are a common target, though their speed and small size makes them harder to catch. More often tiger sharks will prey on cephalopods, crustaceans, sea snakes, turtles, sea birds, and a host of marine mammals like dolphins, dugongs, sea lions, and young, injured, or dead whales. Inadvertently, tiger sharks will also consume garbage such as bottles tires, earning them the nickname 'The Garbage Can of the Ocean'.

Tiger sharks are primarily active at night. Contrary to other sharks, G. cuvier has excellent eyesight, as well as a keen sense of smell. In addition, tiger sharks have two special sensory organs. The lateral line extends down the length of the body and can detect minute vibrations in the water. Ampullae of Lorenzini are small electroreceptors located on the snout; these detect the weak electrical impulses generated by prey. All these features make it easy for tiger sharks to find a meal, and once located their body shape allows them to put on a burst of speed and make quick turns to catch their target. Most of the time, this hunting practice is done alone, but occasionally groups of tiger sharks will gather to scavenge a large carcass or for the mating season.

Male tiger sharks mate every year, while females only reproduce every three years. Breeding seasons differ based on location; in the Northern Hemisphere mating occurs between March and May, while in the Southern Hemisphere it's between November and January. During this time, dozens or even hundreds of sharks may gather to find mates. Females carry their young for up to 16 months, at which time they give live birth. Tiger sharks are ovoviviparous, meaning that eggs are fertilised and hatch inside the mother; this species is also unique in that they employ a technique called embryotrophy, in which young gestate in sacks which are filled with an embryonic fluid. A single litter of tiger sharks may contain between 10 to 80 pups, and each one may live up to 12 years in the wild.

Conservation status: The IUCN has classified the tiger shark as Near Threatened. While exact numbers are unclear, a great many tiger sharks are killed each year for their skin, fins, and liver. This species also has a reputation for vicious attacks, and while they can be aggressive when threatened, only a handful of shark attacks occur each year.

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Photos

Neil Hammerschlag

Brian Skerry

David Snyder

[typhlonectes]

Review of Australian Species of Paracheilinus Fourmanoir (Teleostei: Labridae), with Description of a New Species from the Great Barrier Reef and Coral Sea

#FlasherWrasses

Yi-Kai Tea, Fenton Walsh

Abstract

Australian species of the cirrhilabrin labrid genus  Paracheilinus are reviewed. Four species of Paracheilinus are reported from Australian waters: P. amanda, new species, from Flora, Holmes, and Osprey Reefs, Coral Sea, off northeast Queensland, and Harrier Reef, Great Barrier Reef; P. filamentosus from Lizard Island, Great Barrier Reef; P. flavianalis from Evans and Flinders Shoals, Timor Sea, off northeast Darwin, Northern Territory, and Ashmore, Scott, Seringapatam, and Hibernia Reefs in the north-western shelf of Western Australia; and P. nursalim from Flinders Shoal, Timor Sea, off northern Darwin, Northern Territory.  Paracheilinus amanda, new species, has previously been confused for P. rubricaudalis from Melanesia, but molecular analysis of mitochondrial COI recovers both species as reciprocally monophyletic lineages, differing from each other by 1–1.2% in genetic distance. They further differ in aspects of live coloration of terminal phase (TP) males. Both species are allopatric and do not overlap in distribution. The new species is described on the basis of six specimens: the holotype and two paratypes from Harrier Reef, Great Barrier Reef, one paratype from Flora Reef, Coral Sea, and from two paratypes collected off Hula in southern Papua New Guinea, along the north-western margin of the Coral Sea. The discovery of P. nursalim in Australia represents a new and significant range extension from previous locality records of West Papua and Ambon Bay.  Paracheilinus is rediagnosed, and keys, diagnoses, photographs, and Australian distribution records are presented for all species herein.

Read the paper here:

Review of Australian Species of Paracheilinus Fourmanoir (Teleostei: Labridae), with Description of a New Species from the Great Barrier Reef and Coral Sea (bioone.org)

[rjzimmerman]

Excerpt from this story from EcoWatch:

In the past year, nearly two-thirds of the coral reefs on the planet have been exposed to enough heat stress to trigger bleaching, the United States National Oceanic and Atmospheric Administration (NOAA) said on Thursday, reported Reuters.

Last month, NOAA announced that coral reefs are experiencing a fourth global bleaching event, with El Niño and climate change combining to bring record high ocean temperatures.

“I am very worried about the state of the world’s coral reefs,” said Derek Manzello, coordinator for NOAA’s Coral Reef Watch, as Reuters reported. “We are seeing (ocean temperatures) play out right now that are very extreme in nature.”

Coral bleaching happens when warm ocean surface temperatures cause the colorful algae that live in the tissues of corals to be expelled. Without the symbiotic benefits of the algae, corals turn pale and become vulnerable to disease and starvation.

The current worldwide bleaching event is the second in the past decade, a press release from NOAA said.

“From February 2023 to April 2024, significant coral bleaching has been documented in both the Northern and Southern Hemispheres of each major ocean basin,” Manzello said in the press release.

Since early last year, mass coral bleaching has been confirmed in the Caribbean, Florida, Brazil, Australia’s Great Barrier Reef, the eastern Tropical Pacific, large swaths of the South Pacific, the Gulf of Aden, the Red Sea, the Persian Gulf and other areas of the Indian Ocean.

“As the world’s oceans continue to warm, coral bleaching is becoming more frequent and severe. When these events are sufficiently severe or prolonged, they can cause coral mortality, which hurts the people who depend on the coral reefs for their livelihoods,” Manzello added.

Mass coral bleaching has been documented in at least 62 nations and territories, reported Reuters.

During the previous global event — from 2014 to 2017 — 56.1 percent of coral reefs were subjected to heat stress sufficient to cause bleaching. Another event in 2010 affected 35 percent of reef area, while the first worldwide bleaching in 1998 struck 20 percent of reefs.

[soup-mother]

if they were sustainably wild harvesting from the great southern reef, shirou and saber would have a fate/cray¹ night

¹ southern rock lobster

[mutant-distraction]

The Pink-Backed Pelican. . .

The Pink-Backed Pelican (Pelecanus rufescens) is a fascinating bird native to the swamps and shallow lakes of Africa and southern Arabia. It is a relatively small pelican, with a length ranging from 125 to 155 cm, a wingspan of 2.15 to 2.9 m, and a body mass of 4 to 7 kg. The plumage of this bird is grey and white, with a pinkish hue on the back occasionally apparent (never in the deep pink of a flamingo). The top of the bill is yellow, and the pouch is usually greyish. Breeding adults have long feather plumes on the head.

The Pink-Backed Pelican is an exciting bird to observe. It shares its habitat with the Great White Pelican, which is generally larger and has white instead of greyish plumage. The Pink-Backed Pelican prefers quiet backwaters with shallow water, avoiding steep, vegetated lake banks. It tends to roost and breed in trees (e.g., mangroves) but also perches on sandy islands, cliffs, coral reefs, and sand dunes. Nesting trees have many nests built close together. These nests are re-used yearly until the trees collapse, although the birds generally remain in the area.

The Pink-Backed Pelican is an essential bird in its ecosystem. It feeds mainly on fish but also eats crustaceans and amphibians. The species tends to roost and breed in trees (e.g., mangroves) but will also roost on sandy islands, cliffs, coral reefs, and sand dunes. Nesting trees have many nests built close together. These nests are re-used yearly until the trees collapse, although the birds typically remain in the area.

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Text credit: Earth of Wonders

Image credit: AJ Curtis

[jasfhercallejo]

I've been telling my boyfriend that he has to see Siargao first before we start traveling out of the country, and that Surigao del Norte is my favorite province (tbh I think my new fave province is now Siquijor lol). Looking back, I remember Siargao as the place of my "young and wild" Jasfher era — bar hopping every day, running on the streets in the wee hours of the night super drunk laughing with my barkada who were equally drunk, multiple island hopping, swimming with the stingless jellyfishes, and channeling my inner Sid Lucero (fyi I learned how to surf here in Siargao). It was such an adventurous time.

How time flew by so fast I just know my aching back won't be able to seep up anymore. But you know, aging cannot (and probably will never) stop the thirst for new places of adventures. This time around, I decided to go to Siargao again with Dave, and how delighted we were that his mom also decided to join. Time for some son-in-law and mother-in-law bonding!

I think it’s important to set expectations before coming to Siargao. It's not another Palawan, or Bohol, or Boracay or any other place in the world. Siargao’s vibe is unique, and its appeal doesn’t only lie in its natural beauty. While Siargao is beautiful, and features wonderful attractions such as the Maasin River and the Magpupungko Pools, there are so many other things to do here like the tri-island half-day island hopping tour (Daku, Guyam and Naked Islands) as these islands are easily accessible from General Luna.

Naked Island is a 200-meter-long strip of powdery white sand located off the southern shore of Siargao Island in Surigao Del Norte. The white sand island is completely bare, hence its name. Since there are no trees on the Island to provide shade, the Island is better suited for a quick visit during a Siargao island-hopping tour. Its bare beach also makes for a great spot to soak up some sun if you want to sunbathe. Meanwhile, the surrounding clear waters are perfect for swimming when you want to escape the sun's heat. 

Guyam Island, on the other hand, is quite small. The island is uninhabited similar to the nearby Naked Island and currently does not have any accommodations or cottages. Visitors can only take shade under the palm trees dotting the area. This island is also small enough that visitors can travel around the island on foot within fifteen minutes. Hidden between the palm trees are stalls selling delicious burgers and fresh fruit juices. There are also a few swings and hammocks, perfect if you want to relax for a few minutes.

Daku Island boasts a wide and quiet shoreline, picture-perfect coconut and palm trees on white sand, and just a few villagers. On calm days, snorkeling is a must-do, more so with the clear electric-blue water. On bigger days, the Daku Reef creates a fun wave that is still more forgiving for surfers, as it’s not shallow like most breaks on Siargao.

Among the three islands, Daku is the largest by far, which is why it is particularly ideal for a lunch stop. There are cheap meals at beachside shacks and further inland, but the best way to enjoy lunch here is to bring fresh seafood from General Luna, rent a bungalow hut on the shore, and hire the local beachside cooks for a barbecue feast. Just look at how our dining table is filled with sumptuous seafoods and tropical fruits!