Vanishing Seabirds...and Other Species
This spunky marbled murrelet chick makes appears on the upcoming reissue of Rare Bird by The Mountaineers Books. (Illustration by Paul Harris Jones).
Thanks to the Washington State Audubon list-serve,"The Case of the Vanishing Seabirds" "The Case of the Vanishing Seabird" arrived in my inbox this week. It's fascinating article from Crosscut.com about the marbled murrelet by award-winning science writer, Eric Scigliano.
I am grateful to Scigliano for his article, despite the fact that I was criticized for "neglecting" to address the collapsing Pacific coast fisheries in my book, Rare Bird: Pursuing the Mystery of the Marbled Murrelet.
For the record, Rare Bird was published in the spring of 2005--my research being completed in 2004, shortly after the publication of the UC-Berkeley study, which suggested declining reproduction rates among marbled murrelets could be exacerbated by reduced prey availability, based on observations that murrelets were spending more time diving in pursuit of prey.
I was aware of the UC-Berkeley study prior to its publication, but 1) it was just one study (among hundreds I read on the murrelet),2) the study was based on research conducted in central California (a fraction of the murrelet's range), and 3) I did not feel this newly documented potential threat deserved the kind of focus I devoted to the well-studied, range-wide threats to the murrelet: harvesting of the old-growth forests, catastrophic oil spills and chronic oil pollution, gill-net fishing, and increased nest predation.
Moreover, it was not until 2007 that the UC-Berkeley study on prey species was published--the study containing much of the information I Scigliano says I neglected in my 2005 book. This study--the real subject of Scigliano's article--presents evidence that murrelets have been "feeding down the food chain"--that the historically abundant and fatty prey such as sardines, anchovies, and squid have been overfished and that the murrelets are spending more and more time pursuing smaller and smaller (and less nutritious) fish, including even tiny krill.
Thanks to the Mountaineers Books, Rare Bird is being reissued in paperback this September and in my new epilogue I have addressed the increasingly complex suite of threats facing the marbled murrelet at sea. In addition to a reduction in quantity and quality of their prey species, murrelets continue to face the pernicious threat oil pollution and catastrophic oil spills, which are likely to increase in both the U.S. and Canada with the recent push in domestic oil production. Increases in offshore oil drilling, gas-platform development, shipping traffic (including oil tankers) in the coastal waters where murrelets are most abundant put the species at high risk. Gillnet fishing, though banned in California and in Oregon, is still practiced in Washington, Alaska, and British Columbia. (In B.C. alone, about 550 murrelets drown by entanglement each year as bycatch).
Newly documented threats to murrelets at sea includes entrapment in derelict fishing gear (abandoned gillnets, purse seines, crab pots, and other fishing lines); warming ocean temperatures, changes in upwelling patterns, ocean acidification, sea-level rise, and other climate-change-associated phenomena affect the murrelet's prey species. The frequency of algal blooms and accumulated biotoxins (such as PCBs and PDBE) causes the deaths of seabirds through contaminated their prey species; some algal blooms produce compounds that reduce feather waterproofing and cause hypothermia. Increased levels of domoic acid cause neurological damage among seabirds. Increased aquaculture displaces murrelets from foraging habitat and degrades the spawning ground of their prey fish. Elevated underwater sound disturbance, such as pile driving and detonations has been shown to cause injuries and mortality among seabirds and also disrupt their foraging behavior. Even so-called green energy has a cost: murrelets risk collision with massive underwater wave and tidal turbines in their foraging grounds; onshore and offshore wind turbines add the risk of collision to airborne murrelets if they are placed in the murrelet’s sea-to-forest flight path.
These threats affect not only marbled murrelets--a federally threatened species--but also many other seabirds. The marbled murrelets are considered an indicator species--they are sensitive to changes in the ocean where they spend 95% of their time and in the old-growth coastal forests where the breed.
What they are and have been indicating for several decades is that these ecosystems are badly broken and that the future looks bleak for many species, including our own, as we spend more and more time extracting, harvesting, mining increasingly precious resources.
Thanks to Eric Scigliano for his well-written fascinating article and the opportunity to discuss the important research on the marbled murrelet.