Sea Notes

Two Tales of Bluefin Tuna

Following up on yesterday's post about the fishermen's strike in Japan:

Russ Parsons of the L.A. Times blogs about how strikes and high fuel costs are affecting the availability of tuna and other fresh seafood in the U.S. He also quotes Jesse Marsh of our Seafood Watch fisheries research team on the possible long-term impacts if fuel prices remain high.

Our Stanford University colleagues in Barbara Block's research lab are also blogging, this time about their success in placing electronic data tags on Pacific bluefin tuna during last week's expedition out of San Diego. They put 112 new tags on bluefin, for a total of nearly 550 tagged bluefin in the Pacific since their Tag-A-Giant program began. (Monterey Bay Aquarium partners with Stanford on the program.)

As data come back documenting the migrations of these Pacific fish, we'll begin to get a better picture about their migrations across the ocean. Similar work by the Block lab in the Atlantic has resulted in more than 1,000 tags on giant bluefin over the past decade -- and a comprehensive picture of their travels through the Western Atlantic, the  North Atlantic, Mediterranean and Caribbean.

There's data enough to support a dramatic reduction in fisheries quotas -- if the International Commission for the Conservation of Atlantic Tunas can muster the political will to impose it. Sadly, the commission seems unable to do more than preside over a collapse more dramatic than the 90 percent decline it's already suffered.

Calls for a moratorium on bluefin tuna fishing in the Atlantic were ignored last year. Since then, the European fishery was closed early and European chefs have begun to boycott bluefin tuna. ICCAT has another chance this November. We'll be watching.

Carnival of the Blue 14

It's that time again -- when the best ocean blogging from across the web comes together in the monthly Carnival of the Blue.

This month's edition is hosted by Anthony Townsend at The Blue Economy. Check it out.

Amazing migrations

It seems that every day, satellite tagging and tracking of our ocean wanderers gives us new insights into the underwater world of our ocean planet.

Scientists tracking a basking shark that visited the UK for the summer, found the female shark made a trip of close to 6,000 miles to cross the Atlantic to visit Canada. On occasion, the shark dived to depths of half a mile. Scientists doubt this trip was unique, and may have uncovered a previously unknown migration route. Prior to this, little was known about where this population of basking sharks spent the winter.

The reasons for the shark's long journey, we can only speculate - feeding, mating etc. However, there is perhaps less to ponder when we hear that a polar bear landed on the shores of Iceland recently, about 500 miles off course. Many species around the planet are responding to the pressures of our changing climate. Let's hope we heed their warning.

Learn more about the work of tagging and tracking ocean wildlife at Tagging of Pacific Pelagics website.

The State of the Seas

Not a day goes by without a headline or broadcast report about something happening to the health of the ocean. The news isn't always good, but at least more attention is focused on the largest living space on the planet. With awareness, you open the door for solutions. (In the case of the ocean, ignorance definitely isn't bliss.)

With that in mind, the bad news first:

In the Mediterranean, new research estimates that shark populations are down more than 90 percent from historic levels 200 years ago -- with all the negative impacts on overall ecosystem health that result when you all but eliminate the top predators in the system. Hammerheads, mackerel sharks and blue sharks have been wiped out as accidental bycatch, or killed as pests by fishermen who don't value their place in the ocean's living web. And, sadly, there are still few regulations in place to protect sharks in the wild.

There's also disturbing news about the presence of chemical pollutants in the deep ocean. Scientists surveying deep-water cephalopods in the northwest Atlantic Ocean have detected chemical pollutants (like tributyltin and PCBs) in the tissues of deep-sea squids. Tissue samples from deep-sea squids and octopus -- including the cockatoo squid (Galiteuthis spp.) and the vampire squid (Vampyroteuthis infernalis) -- yielded surprising concentrations of persistent organic pollutants. Chemical like tributyltin (TBT, used in anti-fouling paint on boats), polychlorinated biphenyls (PCBs), DDT and flame retardants were documented in tissue samples collected by scientists in the northwest Atlantic Ocean.

Why worry? Because these cephalopods are an important part of deep-sea food web -- including a source of food for deep-diving whales and dolphins.

On the good-news front, Southern California Edison is spending $40 million to create an artificial reef off the coast of Orange County as mitigation for damage to native kelp forests caused by discharge from its San Onofre nuclear power plant.

The 2.5-mile-long reef, mandated by the state Coastal Commission, is intended to provide footings to anchor giant kelp that will become the basis for a restored kelp forest ecosystem where wildlife can thrive.

Here in Monterey Bay, the return of sea otters from near-extirpation by fur hunters in the 18th and 19th centuries provided conditions for a similar revitalization of the kelp forests. Today, you'd never know that the bay was denuded of kelp by sea urchins, abalone and other grazers after otters were eliminated in the bay. They returned in the early 1960s, and the kelp forest followed them. Keep your eyes on San Clemente to see if the reef there has the same effect.

Finally, a celebration reported this week for "the most important microbe you've never heard of." NPR's Joe Palca took part in commemorating the discovery of a marine bacterium called Prochlorococcus. Why? Because it's super-abundant in the ocean, and is probably responsible for the oxygen in one out of every five breaths you take. Although it's one of the most abundant organisms on Earth, it was utterly unknown to science until 20 years ago.

Monday's Photo: Narwhals

They're called the unicorns of the sea. Narwhals are Arctic dwellers, related to belugas and unique because the left tooth of male narwhals grows into a twisted tusk.

Now, researchers tell us, they may become the poster child for endangered Arctic wildlife.

The March 2008 issue of the journal Ecological Applications is devoted entirely to the topic of "Arctic Marine Mammals and Climate Change." Narwhals are considered the most vulnerable to the impacts of climate change on northern ecosystems.

In an interview with the Associated Press, Stanford University biologist Terry Root (who wasn't part of the study) said the analysis published in the journal reinforces her concern that the narwhal "is going to be one of the first to go extinct" from climate change despite a relatively healthy population today.

"There could a bazillion of them, but if the habitat or the things that they need are not going to be around, they're not going to make it," Root told AP science writer Seth Borenstein.

While polar bears can adapt somewhat to the changing Arctic climate, narwhals can't, Root said.

The journal, published by the Ecological Society of America, evaluated the status of 11 Arctic marine mammals. In addition to narwhals, other species at greatest risk include polar bears, hooded seals, bowhead whales and walruses.

There's a lot we can do -- individually and as a society -- to tackle the growing volume of carbon dioxide we're putting into the atmosphere. It's the challenge of our lifetime, and well worth the effort -- for the narwhals and ourselves.

Bluefin on the brink?

Once again, bluefin tuna are in the news, and once again, it's not good news.

In this month's issue of Conservation Biology there's a call for a five-year moratorium on fishing for bluefin tuna in the western Atlantic, and for the closure of the Gulf of Mexico spawning areas. This follows WWF's recent plea to close fishing for Atlantic bluefin in the Mediterranean.

At the aquarium, we're encouraging our visitors to write to the National Marine Fisheries Service and encourage them to bring an end to overfishing and protect Atlantic bluefin tuna, as well as other overfished species. As we recently reported, scientists do have hope for saving the bluefin, but we must act quickly.

Play the game, courtesy of Ocean Legacy (beware, it is addictive!) and send a letter to ask for stronger rules to prevent overfishing.

Strange Days on Planet Earth

This Earth Day, people around the world are getting active, seeking solutions to a host of environmental challenges that  more of us acknowledge must be addressed now, while we have time to make a difference.

Part of the path to solutions lies in understanding the nature of the problems. A great set of television programs exploring just that airs on Wednesday night.

"Strange Days on Planet Earth," narrated by actor Edward Norton, presents a second season with two hours of programs that look at threats facing the oceans -- including overfishing, unsustainable fish farming and the interconnections between what we do on land and the health of the seas.

It's a project of our friends at Sea Studios Foundation, just down the block on Monterey's Cannery Row. Created in collaboration with National Geographic Television, "Strange Days" will air on a PBS  station near you (our on your DVD player, if you buy a disc to share with family & friends).

"Dirty Secrets" and "Dangerous Catch" address threats to our water supply and the oceans, and the producers challenge us to "find out how we all can make a difference."

Their website offers tools so you can make a difference  --from buying seafood certified by the Marine Stewardship Council to using one of our Seafood Watch pocket guides when you shop for fish.

Check it out & tell your friends. The planet we save is, after all, our own.

Carnival of the Blue 11

It's time again to check out the best of what's being blogged about the ocean and its inhabitants. Check out Carnival of the Blue 11, brought to you this month by the fine folks at Zooillogix. There's even a brief item about the travels of our young white shark.

A Crazy Little Thing Called Love

It's April Fools' Day, but this is no joke.

A UC Berkeley research team has found that at least one species of octopus is quite "romantic" in its approach to reproduction, engaging in rather sophisticated lovemaking tactics such as flirting, passionate handholding and keeping rivals at arms' length.

That's the conclusion from observations in Indonesia of the striped octopus (Octopus Abdopus aculeatus) just described in an article published in the journal Marine Biology.

"This is not a unique species of octopus, which suggests others behave this way," Dr. Roy Caldwell, a professor of integrative biology at UC Berkeley and co-author of the study, told the UC Berkeley news service.

The researchers spotted octopuses staking out the dens of their preferred female mates, attempting to strangle would-be rivals, and saw other males masquerading as females to get a chance to nab the favorites for themselves.

T hey also described the challenges of studying octopuses -- animals both shy and also possessed of keen eyesight.

"They're obsessively secretive, solitary and pretty spooky," Dr. Caldwell said. "If you watch them, they watch you back. It's hard to study them."

There's more to read about their findings, as well as videos (PG rated, at most) and photos.

Enjoy!

White Shark Phones Home

We've been fortunate at Monterey Bay Aquarium to exhibit three juvenile white sharks since 2004, each for a period of a few months. In each case, we returned the young sharks to the wild (equipped with tracking tags). And in each case, they survived and thrived.

The third release took place on February 5. The only difference is that this shark is carrying a Smart Position Only Tag (SPOT tag) that beams in his position via satellite every time his dorsal fin breaks the surface.

In just 44 days, he's traveled from Monterey Bay to Mexican waters just off the coast of Mazatlán.

It's exciting stuff, because it took the second shark we released 90 days to get just as far south as Cabo San Lucas, at the southern tip of Baja California.

It's also exciting because anyone and everyone can check the shark's position, in nearly real time, on the web. Just log onto the Tagging of Pacific Predators site (or link there from our site) and click on the Juvenile White Shark link.

In addition to the three sharks released from our Outer Bay exhibit, we've also worked with research partners to tag a dozen other juvenile white sharks in southern California waters. Since so little is known about their life history as juveniles, this is filling a huge void in the science.

And a better understanding of the movements of young white sharks in the ocean is essential if we want to protect them at this critical stage in their lives.

Where will the shark go next: Farther south? Up into the Sea of Cortez? Log in and find out.