Great white sharks: more here than we knew

Great white sharks are reported in the Hawaiian islands, though rarely.

But new research suggests they may be regular visitors that spend most of their time in deep water around the Islands so they're not noticed. And they've done so for centuries, at least.

Satellite tag data, white shark attacks and sightings all place the sharks in the Hawaiian Islands generally during the first half of the year—no earlier than December, and no later than August.

“It is likely that white sharks have been making these movements for a long time, and there are ancient records of white sharks from Hawaii in native Hawaiian artifacts and history,” wrote researcher Kevin C. Weng, of the University of Hawai'i's School of Ocean and Earth Science and Technology, in an email.

They appear to be white sharks that spend much of their team feeding on the seal and sea lions of the California coast, and which take annual forays into the mid-eastern Pacific—some to Hawai'i and most to other mid-oceanic gathering spots.

Their knowledge of the location of Hawai'i is so clear that satellite tags show that some migrations are fast and straight, from the Baja, California, coast, right to Hawai'i.

The just-published work, “Migration and habitat of white sharks (Carchardodon carcharias) in the eastern Pacific Ocean,” was printed in the journal Marine Biology. Its authors are Weng, along with Andre Boustany, Peter Pyle, Scot Anderson, Adam Brown and Barbara Block.

They report on the satellite tagging of 20 white sharks in the seal rookeries of the Baja Peninsula. Four of those sharks swam to Hawai'i during winter. Others went to other offshore aggregation sites presumably for feeding. The departures coincide with reduced seal and sea lion numbers off California.

Why Hawai'i? The authors in their paper discuss some of the local feeding choices.

“White sharks have been observed near aggregation sites for spinner dolphins on the west side of Oahu, as well as near Hawaiian monk seal colonies on Niihau, and their presence corresponds to the timing of birth for humpback whales, allowing for the possibility of feeding on placentas.

“Sharks may also forage on fishes, sharks and squids while near the islands.”

The sharks that come to Hawai'i don't appear to be of a certain class. They included both male and female, adult and subadult animals.

Why don't see see more of them? Largely because they seem to do their feeding in the deep. The satellite tags suggest that they spend only about 7 percent of their time within 16 feet of the surface.

Based on the limited samples available (4 satellite taggings) the Hawai'i sharks make their moves from the California coast at the same time most of the other white sharks do. They leave when pickings get slim in December or January. And they stay several months—a maximum recorded stay from satellite tagging data of 122 days, although there are reports of white sharks being spotted as late as August..

Anyone who does whale-watching will note that the shark season overlaps the peak of humpback whale season.

Most of the known sightings of great whites in Hawaiian waters have been during the early part of the year, although individuals have reported seeing what they believed were white sharks as late as July and August.

Clearly, the animals have been traveling to Hawai'i for hundreds of years. Some early Hawaiian tools have used the teeth of white sharks for cutting edges.

Two known shark attacks on humans occurred in May 1926, when the remains of William Goins were found inside a 12.5-foot white caught off Kahuku. In March 1969, a white shark bit surfer Licius Lee off Makaha. The animal was identified by its characteristic tooth marks in his surfboard. The area is known for nearby spinner dolphin populations, and there was a dead whale on the beach at about that time.

Hawai'i residents have reported great whites during summer in recent years off Makua, Keawa'ula and Ma'ili. Witnesses said they believe a shark that bit a woman off Ka'anapali in 1999 was a white. And the species has been seen in the waters off northern Ni'ihau repeatedly during the 1990s.

The satellite tagging results confirm the presence of the animals in those regions.

Weng said that there are still several mysteries about the behavior of white sharks, including a suggestion that some females may only return to the California coast every other year.

Does that mean that in places like Hawai'i there might be a year-round great white shark presence? Weng said he can't say, and researchers may have to wait for technology to catch up with the research needs.

Currently available satellite tags don't seem to last more than about 9 months, he said. What's needed is a way to electronically track the sharks for a period of years.

As in much of science, it's a field that demands more research.

© 2007 Jan W. TenBruggencate

Protecting marine life: more than just a ban on harvesting

If you're going to run cattle, you need to not only manage the cows, but also the pasture.

It's a message that seems self-evident, but may be missed by some of those who would manage marine life by banning harvesting alone.

With reef fish, for example, if you seek to protect them, you need to also protect the reef itself. That's the conclusion of Edward DeMartini, of NOAA's Pacific Islands Fisheries Science Center in Honolulu, and Todd Anderson, of San Diego State University. Their study on the subject was published in the Bulletin of Marine Science (2007, Bulletin of Marine Science 81:139-152).

The two studied the behavior of baby fish, including yellow tang, kole and others, at three Big Island locations, one of them a protected site, one open to wind and waves, and one semi-protected.

They found that when possible, they often clustered within the branches of finger corals. The corals provide them two key things: food and protection.

“The Hawaiian-endemic finger coral Porites compressa provides essential habitat for juvenile yellow tang, kole, and numerous other reef fishes,” DeMartini wrote in an email.

“Finger coral provides an essential habitat for many species of herbivorous (algae-eating) fishes because its dead basal surfaces (surfaces on which turf algae proliferate) also provide shelter from predation by fish-eating fishes,” he wrote.

It's clearly not simply that they happen to occur here, but such sites form preferred shelter for these small fish. And that means the little fishes are more likely to survive to become big fishes.

There's more science to be done on the issue, but the scientists said that clearly the complex structure of a healthy reef is an important part of protecting the fish life on it. It suggests, for example, that it's not enough to simply tell people they can't kill a species. You also have to prevent folks from smashing the bottom with boat anchors, from breaking up corals as they walk on the reef, and from letting muddy water smother the nearshore ocean floor.

“Corals habitat also must be protected from destructive human influences such as anchor damage and the sedimentation that results from unregulated coastal development, in order to preserve the juvenile habitat that is necessary for population replenishment,” DeMartini wrote.

© 2007 Jan W. TenBruggencate

When volcanoes collide: Kilauea and Mauna Loa briefly (!) linked underground

Do Mauna Loa and Kilauea draw molten rock from the same source?

Geologists agree that in a larger sense they do—both gain their magma from what's called the Hawaiian plume, a place where molten rock from the earth's core punches up through the mantle of the earth to create volcanoes.

(Image at upper right, from Hawaiian Volcano Observatory, shows current eruption of Kilauea, below Pu'u 'O'o on the East Rift Zone.)

But volcano scientists have long known that chemically, the rocks erupted by Mauna Loa are different from those coming out of Kilauea. That suggests, they say, that while they may both draw from the plume, they probably draw from different places in the plume.

But a new paper says that for a brief moment in geologic time, from about 250 AD to 1400 AD, the two volcanoes were spewing largely the same stuff.

University of Hawai'i geologist Michael Garcia said that the best guess is that during that period, there was a single source that fed both volcanoes, but that both before and after that, lava produced in eruptions of the volcanoes came from different places..

“The notion is that a blob of material was under both volcanoes for a short time in the recent past,” Garcia said in an email.

“Otherwise, the sources of the two closely spaced volcanoes are distinct for many hundreds of thousands of years,” he wrote.

The July 15 issue of the journal “Earth and Planetary Science Letters” contains the paper by Jared Marske, Aaron Pietruszka, Dominique Weis and Michael Rhodes and Garcia. It is entitled, “Rapid passage of a small-scale mantle heterogeneity through the melting regions of Kilauea and Mauna Loa Volcanoes.”

Scientists use all kinds of techniques to try to envision what's under the volcanoes, and the chemistry of rocks is among them. The best assessment is that during this period, during the period Hawaiians were populating the Hawaiian archipelago, coming up from deep in the earth, “there was a filament that was large enough to be tapped by both volcanoes,” Garcia said.

The scientists studied the ratios of isotopes of three elements—lead, strontium and neodymium—in lavas of both volcanoes. Normally, the two volcanoes have distinctly different lava composition, but during the period in question, the compositions seemed to blend into each other.

“The Kilauea lavas span the (lead) isotopic divide that was previously thought to exist between these two volcanoes,” the authors write.

The lavas “moved towards an intermediate composition, and subsequently returned to typical values.”

© 2007 Jan W. TenBruggencate

Superferry: What the Hawai'i Supreme Court really said

Almost everybody has missed key points in the Hawai'i Supreme Court's Superferry ruling.

Not surprising, perhaps. The ruling is 104 pages long. A small book. Who had time to read it on deadline?

Off deadline, we spent some time with it.

The Superferry is a business that proposes to run high-speed passenger-and-cargo vessels between Hawai'i ports.

The Hawai'i Supreme Court shocked the business, environmental and government communities by ruling on an appeal that the state Department of Transportation (DOT) needs to conduct environmental assessment (EA) for its harbor improvements that benefit the Hawai's Superferry, as well as on some of the direct impacts of the Superferry operation itself.

Before a lower court could issue rulings giving force to the Supreme Court decision, the ferry folks decided to start operating.

Kaua'i residents shocked Superferry passengers, the Coast Guard, the state and to some degree the nation when dozens of them leaped into the ocean to form a human blockade preventing its access to Nawiliwili, the primary harbor on Kaua'i.

It made national news.

Many of the protestors argued with the Coast Guard personnel trying to haul them aboard or shove them out of the way. They weren't the lawbreakers, they said, the ferry was.

The Hawai'i Supreme Court ruling is complicated, but it seems clear that the ferry wasn't actually the lawbreaker.

The lawbreaker was the state Department of Transportation, which owns the harbor in which the protesters were swimming.

But it's also clear that the ferry was pretty audacious in deciding to begin running passengers into the seriously murky legal waters created by the court.

Here are some of the results of a reading of the court ruling, which at this writing (Aug. 3, 2007) is being considered by the 2nd Circuit Court on Maui.

A warning: This is going to get a little technical, but not nearly as technical as the actual ruling, which is available on the web from the August 2007 files at: www.courts.state.hi.us/page_server/LegalReferences/73DFB8859867A628EAE7AB3DC5.html.

*** One of the first issues is one that will benefit citizen pro-environment movements for years to come. (We'll get to the Superferry stuff, but this piece of the case may be more important, ultimately, than that.)

The Maui Circuit Court had ruled that the Maui Sierra Club, Maui Tomorrow and the Kahului Harbor Coalition lacked standing—meaning they couldn't claim relief because they weren't sufficiently affected by the DOT's failure to do an EA.

The environmental groups claimed four injuries: threats by the Superferry to endangered marine species; the threat of introducing alien species to the island; limitations due to the Superferry's operation to recreational uses in harbors; and traffic problems. In short, whales, coqui frogs and miconia, canoes and surfers, and finally, traffic jams.

The Supreme Court ruled that they did have a right to sue, that a band of citizens has an interest in whether the state is doing right by the environment—a right sufficient to go take to court.

“If these Appellants do not have standing to bring this claim, it is hard to imagine who, if anyone, would,” the court said.

The Supreme Court said that the right to sue in environmental cases is derived in part directly from the state Constitution, and that legal standing must be more readily granted in environmental cases than in others.

**** The Maui court ruled that even if the environmental groups had standing to sue, the DOT did the right and legal thing in exempting itself from doing an EA.

The DOT asked the state Office of Environmental Quality Contol whether the Superferry harbor improvements fell into a couple of categories for which exemptions from an EA are permitted.

But the Supreme Court said it's not enough for DOT to simply conclude that a project fits into an exemption category--it actually has to make a review and correctly conclude there will be no significant environmental impact.

“...blind deference to agency exemption determinations is not appropriate,” the court wrote.

**** The Supreme Court said that the crucial issue in the case is whether the DOT was right in considering only the specific harbor improvements in deciding not to do an EA. Because, the court said, if it considered the larger issue of the Superferry's overall impact, there would be no question.

“If DOT was required to consider the Superferry project itself, as opposed to the harbor improvements alone, in making this exemption determination, it is clear that the exemption would not apply,” the court said.

That's clear, the court said, in part because of the Superferry's own actions. When the ferry company announced it had developed internal policies to minimize its environmental impact, even though not admitting there would be significant impacts, the comments “make it clear that the Superferry project itself—were its environmental effects considered—does not meet the standard of an exempt action.”

The court said that the DOT clearly failed to consider “whether its facilitation of the Hawaii Superferry Project will probably have minimal or no significant impacts, both primary and secondary, on the environment.”

And in failing to consider that, it was wrong, the court said.

The court ruled DOT's exemption from the EIS process invalid.

“The exemption being invalid, the EA requirement...is applicable,” the court said.

The Supreme Court went on to note that while Hawai'i Superferry's voluntary decision to develop its own environmental policies is a good thing, it's not he same as a public process, which by definition allows public participation.

“The public was prevented from participating in an environmental review process for the Superferry project by DOT's grant of an exemption,” the court said.

**** What's still left unsaid is how broad an environmental review is needed. Clearly, the Supreme Court decision requires that an EA be performed, and must consider both the harbor improvements and “the secondary impacts on the environment that may result from the use of the Hawaii Superferry in conjunction with the harbor improvements.”

Does that mean the Maui court can simply limit the EA to direct impacts of the Superferry on Maui harbor users and Maui island drivers, farmers and so on? Presumably it could, but it's also clear that such a ruling could take it right back on appeal before a Hawai'i Supreme Court that has already expressed serious concern with the legality of such limits.

The court does not specifically say that the DOT needs to do an environmental review that considers the Superferry's statewide impact, but that seems to be the essence of its message. And indeed, in meetings with stakeholders Monday, Sept. 3, the DOT said its EA would in fact include all the island harbors to be used by the Superferry.

*** Some folks have argued that citizens stepped up to the plate too late on the Superferry issue. But most of the same arguments we hear today were being made three years ago when the ferry was before the state Public Utilities Commission for a permit. And the PUC, far from deciding an EA or environmental impact statement (EIS) wasn't necessary, said there were in fact “important issues that should be addressed.”

The PUC failed to require a study, the Supreme Court ruling says in a footnote, because 1) the PUC expected the DOT to consider the issues and 2) the Hawai'i Legislature “has determined that this application should be processed expeditiously.”

© 2007 Jan W. TenBruggencate

Ocean acidity--the next big climate thing

The next big thing in the
climate change debate is
the changing acidity of
the oceans.
Researchers in Hawai'i are
among scientists worldwide
who are tracking the slow
but apparently quite real
movement of the oceans from being slightly basic toward
being acidic.
The argument is that this is a direct result of the
increasing amounts of carbon dioxide in the atmosphere.
(This is going to get a little technical, but
essentially, carbon dioxide, which comes in part
from the burning of oil and coal, is a greenhouse gas.
It's a major cause of global warming. And while there
are still some folks out there debating whether 1. there
is global warming, or 2. whether that's a bad thing--there
is no real debate that 3. the percentage of carbon
dioxide in the atmosphere has increased dramatically
in the past century, and continues to rise.)
(When you mix carbon dioxide with water, you get a mild
acid. More carbon dioxide, a higher concentration of
acid. So at its simplest, that's what's going on with
the oceans—more carbon dioxide in the air, and the
oceans become more acid.)
The Center for Biological Diversity
(www.biologicaldiversity.org) has recently asked seven
coastal states, including Hawai'i, to act on this.
That's because these are the states most likely to
suffer from changing ocean acidity.
The organization has asked Alaska, Florida, Hawai'i,
Oregon, New Jersey, New York and Washington to declare
their coastal waters impaired under the Clean Water Act.
California was asked to do so earlier.
“Ocean acidification is quietly, lethally altering the
fundamental chemistry of the world's oceans. We must
act now to prevent global warming's evil twin, ocean
acidification, from destroying our ocean ecosystems,”
wrote Miyoko Sakashita, an attorney and head of the
center's oceans program.
Alkalinity or acidity is measured on a pH scale from
1 to 14, in which 1 is very acid and 14 is very
alkaline. Neutral is 7.
Lemon juice is quite acid, with a pH of 2.4, while
hand soap, which is alkaline, is about 9 or a little
more.
The oceans are slightly alkaline, at about 8. But with
the increasing carbon dioxide in the atmosphere,
oceanic pH has decreased by a little more than a tenth
of a point. It's not a lot, but nobody knows yet (lot
of research is getting started) at what point the
change begins causing reefs to decompose and sea
creatures' shells to stop forming.
Sakashita says the carbon dioxide is increasing so
rapidly that the oceans will change their pH faster
than species can evolve and adapt.
The Center for Biological Diversity hopes that the
Clean Water Act might be used as a lever to force
changes in the society's production of carbon dioxide.
“If ocean waters are listed (as impaired), the law would
require states to limit carbon dioxide pollution entering
the ocean waters under their jurisdiction,” Sakashita
said in a press release.

© 2007 Jan W. TenBruggencate