30 March 2008

Canaries or canards?

As the Whirligig spins faster, the canaries stop singing, one by one. While it may be outdated, the idea of 'canaries in a coal mine' as a metaphor for the events occurring as we meet our onrushing environmental fate remains useful. The birds go silent – an ill wind blows. Time to heed the warnings or a false alarm?

Bats in New York state are dying, and no one knows why.

Wildlife biologists fear a significant die-off in about 15 caves and mines in New York, as well as at sites in Massachusetts and Vermont. Whatever is killing the bats leaves them unusually thin and, in some cases, dotted with a white fungus. Bat experts fear that what they call White Nose Syndrome may spell doom for several species that keep insect pests under control.

Researchers have yet to determine whether the bats are being killed by a virus, bacteria, toxin, environmental hazard, metabolic disorder or fungus. Some have been found with pneumonia, but that and the fungus are believed to be secondary symptoms.

Of course, climate change could be considered, but it could be through a second-order effect. For example, some subtle alteration in the timing of severity of the seasons could upset the balance of the local ecology, altering the microbial environment and ultimately resulting in dead bats and serious alteration of the local environment. However, discerning the interactions between the myriad variables – their interactions and feedbacks – is difficult work. Ultimate cause and effect is hard to establish.

This is witnessed in the case of the vanishing harlequin frogs in Costa Rica. AS the story notes, '...teams of biologists have been sifting spotty evidence and pointing to various culprits in the widespread vanishing of [the] frogs'. The person quoted below has the correct perspective

“There is so much we still do not know!”... The origin of the fungus and the way it kills amphibians remain unknown and there are ample mysteries about why it breaks out in certain places and times and not others.

Different approaches and paradigms of different researchers lead to different answers. In science, one paper or observation is not definitive...replication is key. And given the complexity of ecosystems, many of the hypotheses may be partially right. It may be years or decades (or never!) before we have certainty that the 'truth' is known.

The disappearing salmon off the California coast are another sign of something gone amiss. The reason for the decline is unclear.

The reason for the decline is unclear. Both hatchery and naturally produced fish have been negatively affected, and returns of coastal stocks in Oregon, in the Columbia River, and in British Columbia were all low in 2007. The decline seems to be a coastwide phenomenon, probably related to ocean conditions.

In Chile, the fishing methods used have been indicted in a salmon virus outbreak. A Change in the Wind has a comprehensive post on the closure of the fisheries and the sources of uncertainty in ascertaining the cause. A link between the Pacific Decadal Osciallation and the number of salmon is explored. As before, nothing is certain. They are many partially correct explanations. Disentangling natural variability vs climate change is next to impossible in the short term.

Are they canaries or canards? The increasingly frequent timing of these events and others like them, in light of the known greenhouse gas forcing and other 'environmental crimes' of humanity, is worrying. But the answers don't come easily. Nonetheless, one can only imagine that whatever Nature's verdict, Humanity will be implicated. Our environmental impacts are enormous. We are the common factor in all these events. Of course we're responsible. And if it doesn't immanently lead to societal and/or ecosystem collapse, then all the luckier for humanity. That gives us more time to act, and allows us to maintain the faint hopes that it is not too late. While success is not assured, despair guarantees failure. Nature always bats last.

Image: Dante Fenolio/Atlanta Botanical Garden via New York Times

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