Blue-ringed octopus (Hapalochlaena sp.) off the coast of the Malaysian states of the island of Borneo. Photo by Laurence Murphy. 2010 National Wildlife Photo Contest entry.

What makes it dangerous?

The blue-ringed octopus can kill a human with a single bite. The tiny cephalopod’s saliva contains a powerful toxin that causes muscle paralysis, including the muscles that control breathing.

Blue-ringed octopuses are not aggressive and will only bite humans if provoked or handled. When agitated, the octopus displays vivid, blue rings that pulsate as a warning to back off.

They can be found in shallow, sandy areas off the coast of Australia and in the western Pacific Ocean.

Check These Sources to Learn More:

• PBS.org – Nature
• University of Michigan – Animal Diversity Web
• Marinebio.org

Australia’s Giant Cuttlefish in Trouble as Weak Spawning Season Continues

Australian giant cuttlefish may be in trouble, as evidenced by low summer spawning numbers (flickr| richard ling)

This summer, numbers are way down.

Australia’s ABC Radio recently interviewed a local commercial fisherman who reported that he has only seen four this year—rather than the usual “hundreds of thousands.” Other news outlets have been picking it up too.

Researchers say the low numbers are cause for concern, and they don’t yet know what’s causing the trend (though “BHP Billiton’s proposed desalination plant” nearby probably won’t help. It would reportedly pour “huge quantities of hypersaline wastewater” into Spencer Gulf and make the area unpalatable for a variety of species). A new study finds that the cuttlefish breeding colony had decreased by 78% in the past decade, and last year marked a record low.

Plan to Exonerate Hawaiian Monk Seals Relies on Reality-TV-style Cameras

Hawaiian Monk Seal photo by: U. S. Fish and WIldlife Service

The image rehabilitation plan comes as local fishermen ramp up  claims that the seals have been depleting area fish stocks. Recent cases of people pestering—and in some cases killing—the seals have come partly as a reaction to these rumors, and spurred scientists to “glue submersible cameras onto the seals’ backs, using the footage to prove to fishermen the animals are not harming their way of life.”

You can find out more about habitat threats to monk seals or read Les Welsh’s blog post from April about people intentionally killing the seals in the waters around Kaua’i (and how you can help).

Video: Blue Shark Chomps Giant Squid

Giant squid are mysterious, awesome and locked in an eternal arms race with sperm whales. Live sightings are so rare that even footage of a recently dead Architeuthis is a pretty big deal. Recently, Australian angler and journalist Al McGlashan came across a largely-intact carcass whose bright red coloration indicated it had died recently. While he filmed, a blue shark tore into the squid, thus launching  the best cephalopod viral phenomenon of 2012 (so far…I eagerly await your videos of octopuses singing ‘Call Me, Maybe’). Take a look at Field & Stream’s exclusive full-length video and photos right this second.

Click here to view the embedded video.

Canadian Lobster is Blue, Yet in Decent Spirits

Canadian lobster boat captain Bobby Stoddard caught a lobster in early May that resembled a giant Avatar cat person. That’s the way we say ‘it was blue’ in America now.

Blue lobsters do occur, but they’re uncommon. According to The University of Maine’s Lobster Institute, “only an estimated one in two million lobsters is blue” (which makes them rare, but not quite as rare as live, naturally red or yellow lobsters, which are estimated at one in ten million and one in 30 million, respectively). Blue lobsters come about due to “a genetic defect that causes the lobster to produce an excessive amount of a particular protein.”

You can learn more about invertebrates in our Wildlife Library.

Manta Ray Ultrasound Sheds Light on Liquid Oxygen Intake

A study recently published in Biology Letters is the first to show how manta ray embryos get oxygen, based on video from an ultrasound performed on a pregnant ray in 2008.

Though manta rays, like many other cartilaginous fish, give birth to live young, they lack an oxygen-giving umbilical cord or placenta. According to researchers, “the baby ray was raising and lowering its jaw, pumping uterine fluid in through its mouth and spiracle.” The continuous regulated flow of the fluid over the ray’s gills allowed the embryo to extract oxygen (the baby was “a healthy female, 2 meters from wingtip to wingtip and weighing 50 kilograms” at birth). According to Taketeru Tomita, a fish biologist at Hokkaido University Museum, this is the first time that scientists have observed fetal viviparious vertebrates pumping liquid to extract oxygen.

Great Whites Summering in Cape Cod

Researchers tag a shark near Chatham, MA, in 2009. Tagged great whites recently returned to Cape Cod to feed on seals. (flickr | Massachusetts Energy and Environmental Affairs)

Researchers say the sharks were drawn to the area by “a growing seal population on Monomoy Island,” redoubt of migrating birds and other non-humans for hundreds of years. They haven’t come close enough to tourist beaches to warrant any official warning, though mayhem will presumably occur if the star-crossed Brody family gets too close.

For more on ocean creatures, see Kevin Coyle’s post from last year about animals’ various methods of swimming or my post about the Top 5 Real Sea Serpents (including the giant squid). You can also check out an article about sperm whales and the threat posed to them after the oil spill in the Gulf  of Mexico.

If you’ve seen a story that you think should be covered in the next Ocean Wildlife Roundup, please let me know in the comments below, email me at greenbergm@nwf.org, or tell me on Twitter @MaxTGreenberg.

A diver photographs a giant manta ray as it glides through Pacific waters off the coast of Socorro Island, Mexico. Photo by Kat Fisher.

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Jim Franks, Senior Research Scientist, Gulf Coast Research Laboratory, Ocean Springs, Miss. Photo: Belinda Serata/NWF

Hyperbole? If you’re visualizing an entire ocean, marshland, bay or miles-long beachfront destroyed, perhaps.

But if you consider pelagic sargassum, that yellowish-brown seaweed that forms up into floating mats, clumps and weed lines (scientists call them “weedrows”), you will find entire habitats destroyed by the Gulf oil disaster.

“It’s really a dynamic, diverse, spectacular open ocean community,” said Jim Franks, senior research scientist, Gulf Coast Research Laboratory (GCRL), Ocean Springs, Miss., about sargassum.

“We’ve actually identified over 130 species of fish that utilize sargassum as habitat at one life stage or another,” he explained.

Researchers Surveying Sargassum

Though it looks like a floating carpet, sargassum grows to three feet deep. Photo: Belinda Serata/NWF

From 2000 to 2004 a team of GCRL scientists, including Dr. Eric Hoffmayer, also of GCRL, and Franks, have studied sargassum.

Team members made 14 sampling cruises in the north central Gulf of Mexico. They used large- and small-mesh nets to target juvenile fish and larvae, and collected samples by towing nets through, adjacent to and below sargassum to a depth of 50 meters.

The final tally of fish that used sargassum as habitat during the sampling cruises came to 110 species, a slight under count because 19 fish could be ranked only by family, not by genus and species.

It’s interesting to note that these surveys specifically targeted juvenile and larval fish. Other animals were collected but no crabs, shrimp or other animals that depend on sargassum were counted. A less scientific, but perhaps equally enlightening experience is to jump into the water near a sargassum mat or, as our lawyers would prefer I recommend, view the habitat from a boat.

Wildlife Using Sargassum for Habitat

You’re likely to see filefish, jacks, blue runners, flyingfish and triggerfish. A few feet deeper swim sharks, dolphin (of the mahi-mahi variety), barracuda, wahoo and mackerel. You might see loggerhead, Kemp’s Ridley, green and hawksbill sea turtle hatchlings. Hanging on to the sargassum might be sea snails.

In the sky, watch for the masked booby, red-necked phalarope and various terns and gulls. The bridled tern often rests on top of the clumps of sargassum.

Sargassum and the Oil Spill

Sargassum is habitat. And a lot of it was wiped out by oil, dispersant and burning. What no one can tell me is how much animal and plant life was destroyed either by oil, chemicals or fire.

“I saw a considerable amount of sargassum that was actually in the oil and in the dispersed oil and in the oil sheens,” said Franks. “We saw a lot of that in our offshore cruise in May. At that point we were about 80 miles south and looping around to 80 miles north of the actual spill site, so we were some distance away,” he added.

Shrimp larvae collected from sargassum mat 80 miles south of Deepwater Horizon well head. Photo: Belinda Serata/NWF

Asked how many fish, shrimp or crab larvae or juveniles were killed in oiled sargassum Franks said, “There’s no way to tell for sure. It’s something we plan to investigate,” he added.

And therein lies the rub. There are very good measurements of very small pieces of the puzzle. After that, it’s a matter of mathematical models, extrapolations and guesswork.

Sea Turtles in Need of Sargassum

Take turtles, for instance. We know that several species of hatchling sea turtles make their way to sargassum mats and live the early part of their lives within those weeds.

So how much oil hit how much sargassum? How many of each turtle species were there when the oil hit? What were the effects of the oil on sargassum and baby turtles? How many turtles were harmed or killed and how many made it through ok?

More about how the Gulf oil disaster impacted sea turtles >>

A 2008 study by the Florida Fish and Wildlife Research Institute surveyed sargassum habitats for neonate (i.e., hatchling) sea turtles. The study found 60 sea turtles per square kilometer of sargassum habitat (30 green turtles and 30 Kemp’s Ridleys) in one survey area off Pensacola, the smallest of six survey areas around Florida (four in the Gulf, two in the Atlantic).

So all you have to do is figure out how much sargassum is out there, and how much of it was hit by oil and chemical dispersants, and you can generate at least an estimate of the number of baby green and Kemp’s Ridley sea turtles that were impacted by the Gulf oil disaster — maybe even stretch to say “harmed” by oil and chemicals.

That’s what the Natural Resource Damage Assessment (NRDA) is trying to figure out. And it’s not just about the nature. It’s about money — fines and penalties and lawsuits. Which means the lawyers should do just fine.

But the sargassum is gone — destroyed and sunk to the Gulf floor. And with it, the habitat for baby sea turtles and a myriad of other marine newborns.