Perhaps the most important message the Discovery Channel’s Shark Week can deliver is not how sharks may be dangerous, but how these fantastic fish are in danger.

While it’s hard to estimate the total number of sharks killed each year by humans, due to the illegal and unregulated nature of practices like shark finning, some studies put the number at around 100 million per year, says Shark Stewards’ founder David McGuire. The World Wildlife Fund reports that this number is also growing at about 5% each year.

McGuire, also an Academy research associate and a lecturer at the University of San Francisco, calls himself a “conservationist with science training” who hopes to spend the rest of his life protecting sharks.

He earned his shark chops here at the Academy, working with, and learning from, the amazing John McCosker, who has spent his life swimming with fewer and fewer sharks.

McGuire began telling his shark tales with a documentary in 2006 called “Shark Stewards of the Reef,” documenting the connection between sharks and coral reefs and highlighting the important role these top predators play in supporting the health of coral reefs.

A few years later, he was on the front lines of the shark fin ban here in California, which was successfully passed into law in 2011.

As McGuire has watched more states join the ban and other organizations get involved here in the United States, he’s moved his sights to Asia, to create more awareness about the plight of sharks worldwide. He’s working with eco-tourism and ecosystem restoration organizations, as well as focusing on educating a public that might consume sharks and shark fins without truly understanding the consequences to the health of the fish and the oceans in general.

After returning from a three-week trip to Cambodia, Malaysia, and Hong Kong, McGuire stopped by the Academy this week to give us an update on his work. “The idea is to bridge American relationships and resources to small grassroots organizations in Asia, as well as bring the message of shark conservation in a good way, not pointing fingers. We want people to have the information to make better decisions,” he explains.

Shark Stewards recently joined the Earth Island Institute in order to further its cause. McGuire is working on ads and videos providing solutions to the overhunting of sharks and recently organized two “Swim for Sharks” awareness events—3.5 mile swims here in San Francisco and also in Hong Kong, the center of the shark fin trade.

McGuire won’t stop in the fight for shark conservation. “It’s daunting,” he says of the work ahead in Asia, “but it’s also exciting.”

Follow McGuire’s work on his blog.

Image: David McGuire

Top predators (think sharks, lions, wolves) may eat many animals within an environment, but they also keep the ecosystem in check.

This may seem counter-intuitive, but according to science writer Mary Ellen Hannibal, “We need a full complement of species on wild landscapes so that nature can fulfill its whole cycle.  It turns out that top predators—the wolf, for example—play an outsize role in keeping the whole system together.”

This was, in fact, the subject of her very excellent OpEd piece in the New York Times last fall entitled, “Why the Beaver Should Thank the Wolf.”

And scientific studies reflect this, too. A study out this week in the Journal of Animal Ecology demonstrates why the grizzly bear should also thank the wolf.

Bill Ripple, Bob Beschta, and their colleagues discovered that the return of wolves to Yellowstone National Park is beginning to bring back a key part of the diet of grizzly bears that has been missing for much of the past century—berries that help bears put on fat before going into hibernation.

“Wild fruit is typically an important part of grizzly bear diet, especially in late summer when they are trying to gain weight as rapidly as possible before winter hibernation,” Ripple says. “Berries are one part of a diverse food source that aids bear survival and reproduction, and at certain times of the year can be more than half their diet in many places in North America.”

Looking at bear scat, the researchers found that the level of berries consumed by Yellowstone grizzlies is significantly higher now that shrubs are starting to recover following the re-introduction of wolves, which have reduced over-browsing by elk herds. The berry bushes also produce flowers of value to pollinators such as butterflies, insects, and hummingbirds; food for other small and large mammals; and special benefits to birds.

When wolves were removed from Yellowstone early in the 1920s, increased browsing by elk herds caused the demise of young aspen and willow trees—a favorite food—along with many berry-producing shrubs and tall, herbaceous plants. The recovery of those trees and other food sources since the re-introduction of wolves in the 1990s has had a profound impact on the Yellowstone ecosystem, researchers say.

Hannibal points out that Beschta and Ripple didn’t set out to study wolves. In an email to Science Today, she says, “They set out to study the health of the Lamar River… But in looking for a cause to explain the degradation of the river, what they found is that super-abundant elk were eating the vegetation down to the roots on the river banks, and the vegetation wasn’t able to ‘recruit,’ or grow up strong and healthy. When wolves were reintroduced to Yellowstone, the vegetation started to recover. Beschta and Ripple and many other scientists documented this and analyzed it, and it turns out that elk change their behavior when wolves are around, and they stay on the move, which gives the vegetation time to recover.”

“Studies like this point to the need for an ecologically effective number of wolves,” Beschta says in a press release. “As we learn more about the cascading effects they have on ecosystems, the issue may be more than having just enough individual wolves so they can survive as a species. In some situations, we may wish to consider the numbers necessary to help control overbrowsing, allow tree and shrub recovery, and restore ecosystem health.”

Beschta’s and Ripple’s work is featured in Hannibal’s Spine of the Continent, a great story of conservation efforts to create wildlife corridors to protect these top predators and the ecosystems that depend on them. Look for more of these stories here in Science Today, and in an Academy exhibit, Life Connected, opening in Spring 2014.

Image: Bobisbob at en.wikipedia

At over three feet, you’d think the solo coral grouper would be threatening enough. Threatening sure, but a successful lone hunter? Well, not so much, according to National Geographic News Watch:

When hunting alone, groupers only catch their prey about 1 out of every 20 attempts.

So the grouper teams up with the even fiercer moray eel, or the very large Napolean wrasse, to go hunting. The fish are looking for smaller coral reef fishes that hide from their predators under rocks and coral. When the grouper detects the hiding prey, it signals its hunting friend and together they both flush the prey out of hiding.

The cooperation, however, ends there. Whoever gets the prey, eats it whole. There’s no sharing of the spoils. Still, for the grouper, it’s worth the shared hunting, says National Geographic News Watch:

When they have help, the ratio is significantly better—about one out of seven.

What’s most significant about this shared hunting are the signals the grouper makes to its partner during the hunt, say scientists. Researchers studying the fish observed dozens of events where groupers performed upside-down headstands with concurrent head shakes to indicate the presence and location of particular prey to cooperative partners. Their study, published last week in Nature Communications, call the groupers’ signals “referential gestures”. From the abstract:

In humans, referential gestures intentionally draw the attention of a partner to an object of mutual interest, and are considered a key element in language development. Outside humans, referential gestures have only been attributed to great apes and, most recently, ravens.

It’s likely that these gestures have been understudied in non-primate species, say Academy researchers, who point to hunting dogs and even bee dances as potential consideration for referential gestures.

The researchers of the study say that the mental processes underlying these gestures in fish, apes and ravens are unclear and may well vary among these taxa. Their findings point to the fish having developed cognitive skills according to their particular ecological needs.

Whatever the cause, these hunting tactics are pretty extraordinary. Videos of the behaviors can be found here. For more information on the study, visit the University of Cambridge website.

Image: jon hanson/Wikipedia