The Southern sea otter population is healthy at the core of its range along the California coast, but the aquatic mammals are still struggling to expand north and south, probably because of predation by sharks, scientists said as they released the results of the latest annual otter survey.
“The population index has exceeded 3,090 for the first time, and that’s encouraging,” said Lilian Carswell, Southern Sea Otter Recovery Coordinator for USFWS, referring to a threshold number for recovery. If the population stays above that number for three years in a row, the U.S. Fish and Wildlife Service could consider a delisting proposal.Sea otters were presumed to be extinct in California in the early 1900s, but a remnant population of 30 animals was discovered and protected in the 1930s near Bixby Bay, north of Big Sur. They were listed as a threatened species in 1977, deemed at risk from oil spills. Continue reading “California sea otter population growing steadily”→
For now, the world’s oceans are sucking up so much carbon dioxide that it’s helping to slow the rate of global warming. But that’s expected to change in the future, researchers warned after taking a detailed look at the rate of ocean acidification in the northeast Pacific Ocean. Continue reading “How long can the oceans soak up CO2?”→
New website highlights the widespread problem of plastic debris
Microplastic pollution is widespread in many rivers flowing into the Great Lakes, according to U.S. Geological Survey scientists who recently took water samples from 29 Great Lakes tributaries in Minnesota, Wisconsin, Indiana, Michigan, Ohio and New York. The researchers found microplastics in all those streams, which together make up about 22 percent of the water flowing into the Great Lakes.
Systemic pesticides seen to affect hives in various ways
A new study led by a University of Nebraska-Lincoln entomologist reinforces the link between neonicotinoid pesticides and declining honeybee colonies. The researchers experimentally fed queen bees with a syrup laced with imidacloprid, finding that queens laid significantly fewer eggs than queens in unexposed colonies.
“The queens are of particular importance because they’re the only reproductive individual laying eggs in the colony,” said lead author Judy Wu-Smart, assistant professor of entomology. “One queen can lay up to 1,000 eggs a day. If her ability to lay eggs is reduced, that is a subtle effect that isn’t (immediately) noticeable but translates to really dramatic consequences for the colony.” Continue reading “Queen bees exposed to neonicotinoids lay fewer eggs”→
As if toxic waste from chemical manufacturing and other industrial processes weren’t enough, scientists say some streams are also being fouled by remnants of amphetamines — in some cases at high enough levels to alter the base of aquatic food chain.
A new study, published in the journal Environmental Science & Technology, traced the presence of illicit drugs at six stream sites around Baltimore, focusing on the Gwynns Falls watershed, which is part of the Baltimore Ecosystem Study Long-Term Ecological Research program. Two rural streams were also sampled in the Oregon Ridge watershed, the closest forested region. Continue reading “Study tracks amphetamine pollution in Baltimore streams”→
New study suggests climate is very sensitive to greenhouse gases
Although the rate of global warming has increased dramatically in the last few decades, a new study suggests that human activities have been driving climate change for the past 180 years. The findings suggest that global warming is not just a 20th century phenomenon, and that the climate system is, indeed, quite sensitive to the buildup of heat-trapping pollution.
The study was led by Nerilie Abram, of The Australian National University, who warming began during the early stages of the Industrial Revolution and started leaving a fingerprint in the Arctic and tropical oceans around the 1830s, much earlier than scientists had expected. Continue reading “Global warming started earlier than you think”→
Disease may be exacerbated by warm water, low stream flows
The Yellowstone River, part of Montana’s iconic western landscape, is once again beset by environmental woes, as a rapidly spreading fish kill has spurred state resource managers to close the river to all recreational uses, including fishing, boating and tubing. Biologists with Montana Fish, Wildlife and Parks said they’ve counted more than 2,000 dead mountain whitefish, and the estimate the total mortality in the tens of thousands. The river was also hammered by an oilspill in 2011 after pipeline burst. Continue reading “Environment: Massive fish kill reported in Yellowstone River”→