Tag: seabirds

Stealing Fish To Study Seabirds

Scientists are snatching fish from Rhinoceros Auklets to find out how much pollution they're exposed to in their diets. Seabird populations in Puget Sound have declined since the 1970s. | credit: Peter Hodum
Scientists are snatching fish from Rhinoceros Auklets to find out how much pollution they’re exposed to in their diets. Seabird populations in Puget Sound have declined since the 1970s. | credit: Peter Hodum

 

By Ashley Ahearn, KUOW

SEATTLE — Seabird populations in Puget Sound have declined since the 1970s and scientists believe pollution is partially to blame.

But how do you prove that? Study what the seabirds are eating. A new paper published in the journal Marine Pollution Bulletin found that seabirds in Puget Sound are eating fish that are two to four times more contaminated than fish on Washington’s outer coast.

To gather the data, scientists camped out on three remote islands – one in Puget Sound and the other two on Washington’s outer coast – that are nesting spots for Rhinoceros Auklets, a small dark seabird shaped “like a football,” said Tom Good, the lead author of the study and a biologist with the National Oceanic and Atmospheric Administration in Seattle.

Good and his team waited in the dark for the mom and dad auklets to fly home with beaks full of fish for their chicks. Then, when the birds landed, the scientists flashed on their headlamps, startling the birds so they would drop their fish.

Watch: Rhinoceros Auklets landing at a remote island as scientists wait.

“It’s called spotlighting,” Good explained.

“It sounds worse than it is,” Good said, “but yeah, we’re stealing food from the mouths of babes, basically.”

Good didn’t harm any birds in his research. And the confiscated fish provided an immense amount of data.

Chinook salmon, sandlance and herring were the main items on the auklet menu. The top three pollutants found in the fish were PCBs, DDT and flame retardants.

Salmon samples taken from auklets on Tatoosh Island, near the mouth of the Strait of Juan de Fuca, had the lowest levels of contaminants, when compared to salmon caught at the other two islands in Puget Sound and along Washington’s outer coast.

Mink will be trapped to right the wrongs of Exxon Valdez

By John Upton, Grist

Pigeon guillemots
Jerry Kirkhart
Pigeon guillemots, a kind of puffin.

 

Nearly a quarter of a century after the Exxon Valdez crashed and spewed 11 million gallons of crude into Prince William Sound, one species of seabird still has not recovered from the disaster. To help it recover, the federal government is proposing to get rid of lots of American minks. Allow us to explain.

Thousands of pigeon guillemots were killed by the Valdez disaster — some coated with oil, others poisoned by it for a decade afterward. The guillemots are the only marine bird still listed as “not recovering” from the accident; the local population is less than half what it was before the spill.

The birds used to flourish on the Naked Island group in the middle of the sound, but fewer than 100 remain there now. To boost that number back up to the pre-spill level of 1,000, the U.S. Fish and Wildlife Service is proposing to trap most of the islands’ American minks — aquatic ferret-like creatures that feast on the birds’ chicks and eggs. If trapping doesn’t work, shooting the minks is the backup plan.

 

American mink
Leo-Avalon
American mink.

 

The minks are native to the region, but nobody knows for sure whether they are native to the islands in question. What scientists do know is that the islands’ mink populations skyrocketed in the immediate aftermath of the 1989 spill. “[T]he increase in mink caused pigeon guillemots and other bird species (whose nests are susceptible to mink predation) to decline significantly,” the FWS wrote in a draft environmental assessment detailing its proposal.

From the Alaska Dispatch:

Figuring out how many mink to remove is “the hard part,” [FWS seabird coordinator David] Irons said, as the exact number inhabiting the cluster of islands is unknown, although their numbers are estimated to range roughly from 200-300.

By removing the mink, several other species of birds that nest on the islands would benefit as well, Iron said. Parakeet auklets, tufted puffins and horned puffins have also been on the decline in the past decades, but those birds are not on the [Exxon Valdez oil spill] Trustee Council’s list of affected animals.

“Right now Naked Island is a desert of birds — it used to be a hot spot,” Irons said, adding that the Prince William Sound used to be home to 700 parakeet auklets, whereas now only around 40 remain.

It’s hard to imagine how an oil spill would cause a mink population to explode. But Irons points out that that’s not the main concern — what’s important to the Exxon Valdez oil spill Trustee Council is that the birds “were affected by the oil spill” and it is therefore the council’s responsibility to do what it can to help them out, drawing on $900 million in civil penalties paid by Exxon.

This map shows the Naked Island group. The Exxon Valdez ran aground bear Bligh Island.

Prince William Sound
U.S. Fish & Wildlife Service