Every Bird Matters
news and views from international bird rescue

Posts Tagged ‘study’

September 22, 2009

Clues starting to surface in Farallones bird deaths

The outbreak of seabird deaths this spring and summer in Northern California has scientists turning their attention to krill and how some animals can adapt to changing foodstocks and others don’t.

In a story in the San Francisco Chronicle today, researchers are studying how the disappearance of Anchovies – that left diving birds like Cormorants starving – has affected other animals like humpback whales.

The whales adapt better and have turned their feeding attention to more krill, a type of shrimp-like marine invertebrate animal. Cormorants haven’t or can’t adapt to feeding on other forms of ocean food.

“We’ve had an extraordinary number of dead animals,” said Jan Roletto, the research coordinator for the Gulf of the Farallones National Marine Sanctuary. “It seems to be that the animals that suffered the most were the animals that forage on anchovies.”

Here at IBRRC we saw huge numbers of dead and dying Brandt’s cormorants along beaches in Central and Northern California. The birds can dive as deep as 300 feet for prey. According to PRBO researchers the birds did not produce any chicks this year on the Farallones or on Alcatraz Islands. This is compared to a total of 15,000 chicks in 2007.

According to scientists, the Cassin’s Auklet, a small seabird that feeds on krill, has had above-average nesting success this year.

Read more: Hunt for clues to sea life deaths at Farallones

August 17, 2009

Bird hazing twist at airports: Warning birds visually

A new idea in hazing birds from busy airport flight paths includes the idea that birds can be warned when they’re in harms way. According to a recent NPR news report, some wildlife biologists are testing their theory by communicating with them visually.

“Vision is the primary sensory pathway in birds,” says a researcher. He and his research team hope to “play upon that sensory pathway, understand it and use the lights that are on the aircraft basically to buy time for the aircraft — and buy time for the birds.”

After US Airways jet hit geese after takeoff from a New York airport and made an emergency landing in the Hudson River in January, it turned spotlight on the high level of bird strikes. Airports try a lot of tricks to keep birds away, but now some researchers are shining light on a possible solution.

At Plum Brook Station, a 6,000-acre, high-security government campus near Sandusky, Ohio, scientists are literally flying a plane at groups of geese and watching how they react. It’s a radio-controlled model plane — a 9-foot wingspan aircraft that looks like a miniature Cessna.

It’s a phenomenon that others have investigated less formally. One effort mentioned in a National Transportation Safety Board report in May was by Qantas Airlines. The Australian carrier reported a 10- to 40-percent drop in bird strike rates after they mounted pulsating lights on their 737s.

Read and listen to the full report on the NPR website

June 2, 2009

Fishing line injury study: Pelicans most affected

A recent study has concluded, not surprising, that pelicans suffer the most fishing line injuries. Over 30% of the animals harmed by fish hooks and entangled fishing line were Brown Pelicans.

The report was published in the Journal of Wildlife Diseases, 45(2), 2009, pp. 355–362. The report was authored by Brynie Kaplan Dau including contributors, Jay Holcomb of IBRRC, Kirsten V. K. Gilardi and Michael H. Ziccardi of UC Davis’ Wildlife Health Center.

The study says that pelican injuries caused by fishing gear were most common in the
Monterey Bay region, where 59.6% of the pelicans rescued and admitted to a
rehabilitation center were injured by fishing gear over the 6-yr period.

The highest prevalence of fishing gear–related injury in gulls was documented in the Los Angeles/Orange County region (16.1%), whereas the highest prevalences in pinnipeds (elephant and harbor seals) were seen in the San Diego region (3.7%).

A total of 9,668 cases were included in this study, of which 1,090 (11.3%) were
fishing gear–related injuries.

To reduce risk of injury and death for coastal marine wildlife and people, the SeaDoc Society, a marine ecosystem health program of the University of California Davis Wildlife Health Center, launched the California Lost Fishing Gear Recovery Project in 2005. To date, more than 11 tons of lost fishing gear have been removed from near shore marine waters surrounding the Channel Islands, and hundreds of pounds of recreational fishing gear (such as fishing line and hooks, tackle, and ropes) have been cleaned off public-access fishing piers.

To prevent the reaccumulation of discarded gear at these piers, monofilament disposal stations have been established on many coastal public piers.

The paper was published in the Journal of Wildlife Diseases. Read the abstract

May 17, 2009

Studying natural oil seepage in Santa Barbara area

There’s an excellent report on the Santa Barbara natural oil seepage from the Woods Hole Oceanographic Institution. The study documents the 5,280 to 6,600 gallons (nearly 20 to 25 tons) of oil per day that seeps into the area waters and has been active for hundreds to thousands of years. In earlier days local Native Americans used the oil to waterproof their boats.

From the online report:

The water was calm and flat—dampened by a widespread, iridescent film of oil on the surface. Big oil patties floated about. The air smelled like diesel fuel.

By any definition, it was a classic oil spill. But we were the only boat in the area—no Coast Guard, no oil booms, no throngs of cleanup crews in white Tyvek suits, no helicopters, no media, and no shipwreck.

Why? Because this oil spill was entirely natural. The oil had seeped from reservoirs below the seafloor, leaked through cracks in the crust about 150 feet (45 meters) under water. Lighter than seawater, the escaped oil floated to the ocean surface.

Read more & view photos: While Oil Gently Seeps from the Seafloor

May 13, 2009

Mystery solved: Why big Mercury levels in ocean fish

Scientists have gotten closer to figuring out why ocean fish have high levels of Mercury even though the levels of the chemical aren’t that high in surrounding Pacific Ocean waters. >> See Mercury cycle explained by Oceana

A new study has concluded that the Pacific Ocean absorbs Mercury from the pollutants in the atmosphere where it sinks and decomposes into deeper water and then releases a highly toxic form of the metal that poisons fish.

According to the report, the mercury pollution is a byproduct of coal combustion, industrial waste and other human activities. The study also projects a 50 percent increase in mercury in the Pacific Ocean by 2050 if mercury emission rates continue to climb. From the mid 1990s to 2006, mercury levels increased 30 percent in the ocean.

The study was released this month by a group of scientists from the United States Geological Survey. >> Read full USGS study

Media story:

Link between air pollution, contaminated seafood: New York Times

How to Avoid Mercury When Buying Fish: Oceana

February 23, 2009

Study: Seabird deaths linked to red-tide foam

An important new study about the 2007 Monterey Bay bird die off is pointing toward a red-tide algae bloom that induced a dangerous sea foam. According to the study, the birds feathers lost their water-repellant nature after being coated with the foam.

The main species in the red tide was a type of dinoflagellate known as Akashiwo sanguinea. The red tide event hit when large numbers of migrating birds had arrived in the area. Also big waves churned up the water creating the sea foam that stripped birds feathers of natural insulating properties.

Birds affected included grebes, loons, northern fulmars, and surf scoters. Stranded birds were found starving and severely hypothermic. Nearly 600 birds were located alive and 207 were found dead during this event.

According to the report, freshly stranded birds had a pungent odor similar to that of linseed oil while still wet, but with time, this material dried, leaving a fine, pale yellow crust with minimal smell.

Raphael Kudela, professor of ocean sciences at the University of California, Santa Cruz, teamed up with scientists from California Department of Fish and Game (CDFG), Monterey Bay Aquarium Research Institute (MBARI), and Moss Landing Marine Laboratories (MLML)–all members of the Central and Northern California Ocean Observing System (CeNCOOS).

These kinds of red-tide events may occur more often in the future, Kulea said. These changes are probably due in part to the effects of climate change on surface water temperatures.

The study alludes to another interesting fact about other compounds in the bay worth studying:

…Extracts of seawater from four areas in northern Monterey Bay heavily impacted by the red tide were analyzed for polar and non-polar compounds by gas- and liquid chromatography-mass spectroscopy and were found to be negative for petroleum compounds, commercial surfactants, pesticides, domoic acid, okadaic acid, and microcystin toxins. However, samples of the co-occurring surface foam present at these same sites contained significant concentrations of an organic compound with a predominant chromatographic peak at 1230 mw, corresponding to a m/z 616 dimer composed of carbon, hydrogen, nitrogen and oxygen…

Researchers are releasing this study through an online journal called PLoS One: Mass Stranding of Marine Birds Caused by a Surfactant-Producing Red Tide

Read the Press Release on the UC Santa Cruz website

February 11, 2009

Another wake up call: Global warming and birds

If you’ve been on the fence regarding global warming, here’s a sobering Audubon California report that should move you to some sort of action.

The study released Tuesday finds that California will lose significant numbers of its native birds as the continuing shifts in climate change quickly shrinks the range and habitat of more than 100 species. See Audubon website

According to the report:

Climate change is already pushing species globally poleward and higher in elevation. In California, directional changes in climate during the 20th century were substantial. Throughout this period, and in the centuries before, California also experienced cyclical changes as a result of a weather pattern known as the Pacific Decadal Oscillation4. Hence, bird species in California have managed to survive various forms of past climate change, often by shifting their distributions around the state. But will they be able to continue to respond to future changes of a much larger magnitude?

Two factors argue that they will not. The first is that our current network of protected lands was not designed to buffer species, communities, and whole ecosystems against large-scale processes like climate change. The second is that the major climate variables influencing species’ distributions are expected to change so quickly that even highly mobile species like birds will be unable to keep pace. Hence, future climate change threatens California’s birds with massive range reductions and, in extreme cases, statewide extirpations and global extinctions.

These dire predictions are based on models of future climates, and serve as a companion to a nation-wide Audubon Society study. Using data collected over the past 40 years, that study concluded that 177 bird species in the U.S. are spending the winter farther north because of a warming world.

In California, scientists worry that the quickly warming climate might not only force certain species to move northward, but wipe out others that are not quick to adapt.

At IBRRC our observation and treatment of sick Brown Pelicans these last two months seems to support our concerns. In fall 2008, Pelicans spent longer in the north where fish stocks seem to be more plentiful. When the weather changed quickly in Oregon and Washington, they got stuck in freezing temperatures and fled south. Some got off course and other died in route. Over 200 ended up being treated at our California bird centers. See: Update on California Brown Pelicans in distress

All is not lost. The study suggests that if we can significantly curb our output of greenhouse gas emissions (cars, factories) and invest in conservation (walk, bus, bike, invest in a lower wattage footprint) we can greatly reduce the damage.

Come on folks, this is not a drill. Our health, planet and bird’s lives depend on us to get off our butts!

Read: Curbing greenhouse gas emissions will reduce future California bird loss (PDF download)

November 1, 2008

Has S.F. Bay recovered a year after oil spill?

Lots of stories will emerge this month on how the fragile San Francisco Bay is doing following last year’s Cosco Busan oil spill. Most of them so far seem to have swallowed the state’s reports verbatim.

The first that I saw is from the San Francisco Chronicle: S.F. Bay seems recovered a year after oil spill

You can certainly debate how well the bay has recovered. I don’t pretend to be a biologist, but common sense – if earlier oil spills are any indication – tells us that longer periods of study are required. See: NOAA: Remaining impacts of Exxon Valdez spill

From a Mother Jones report, Oil Spills are Forever:

In the wake of the 1989 Exxon Valdez disaster, scientists have traced much of the trouble to polycyclic aromatic hydrocarbons, or PAHs, an especially persistent family of chemicals found in oil that can cause deformities, slower growth, and poorer reproduction in many birds and animals.

Read more online about this issue and a interview with Riki Ott who a trained marine toxicologist, she has studied the bilogical and societial issues surrounding the Exxon Valdez spill.

Even a government scientific report posted online, suggests that further study is in order:

…State and federal trustee agencies have been assessing the ecological injuries and impacts to human activities
caused by the Cosco Busan oil spill…1,859 [birds] collected dead, hundreds observed oiled but not captured. Total mortality estimation, taking into account birds missed and scavenged, and dead birds not related to the spill, is on-going. Recovery times will vary across species.

See: Natural Resource Damage Assessment for Cosco Busan Oil Spill (PDF)

August 6, 2008

Record numbers of Pelicans on Farallon Islands

There’s tell tale research from scientists studying Brown Pelicans on the Farallon Islands: The numbers are way up.

Researchers at the Point Reyes Bird Observatory (PRBO) counted a new peak of 5,856 pelicans on the the islands. The low was in 1968 when only 363 pelicans were counted.

“Only in 1984 were there counts over 5,000 on the island,” said PRBO biologist Russ Bradley. “The birds have now covered the marine terrace and are roosting in huge numbers in many other areas of the island as well. This number may increase, as pelican abundance usually peaks in the fall.”

This may explain the huge numbers of pelicans spotted foraging for fish in Northern California. The pelicans have been colliding and competing with fishermen especially along the Santa Cruz County coast where they’ve congregating near fishing piers. IBRRC has been treating hundreds of injured, starving and sick pelicans since mid-year.

Pelicans have made a major comeback after facing extinction from exposure to DDT other man-made factors in California 40 years ago. This year the U.S. government is leaning on removing the majestic bird from the endangered species list.

Read the full story in the Marin IJ or see the PRBO website