By George Stubbs
The Melrose Recycling Committee has in the past year taken a longer look at food waste and the significant fraction of our waste stream that it constitutes. We have noted that the United States wastes up to 40% of food every year, amounting about $165 billion dollars in value left on the table—or in landfills, fields, roadsides, oceans, and waterways—and we provide supporting documentation of these and other facts about food waste on our compost web page.
Now it appears that all that wasted food is having impacts—many of them negative—on the world’s wildlife. The general pattern is this: large amounts of food discarded in landfills or at other land-based sites, or at sea by fishing operations, are attracting opportunistic species that thereby multiply and then crowd out other species, some of which are already endangered or threatened.
Writing for Yale Environment 360, a publication of the Yale School of Forestry & Environmental Studies, National Magazine Award-winning journalist Richard Conniff catches us up with a study investigating the fate of steelhead trout in Monterey Bay. The study, conducted by marine ecologists at the University of California-Santa Cruz and published in the journal Biological Conservation, notes that the steelhead trout population in the bay has declined by upwards of 90% over the past century, and the study investigates the role that waste disposal and fishery discards may be playing in that decline.
What the study finds is that Western gulls have been “subsidized” by mounting volumes of easily available food wastes, on land at uncovered municipal solid waste landfills or at sea by dumped fish remains, and they have been multiplying substantially. The gulls, whose numbers have as much as quadrupled in parts of the bay over the last few decades, have turned to preying on juvenile steelhead, forcing other fish-eating birds, such as Brandt’s cormorants and marbled murrelets, to shift down the food chain for sustenance.
Conniff writes that, following a similar pattern, yellow-legged gulls in the western Mediterranean Sea, are putting pressure on species such as European storm petrels and Auduoin’s gulls. Meanwhile, back here in the U.S., ravens and coyotes in the Mojave Desert are feeding on municipal garbage, multiplying, and compromising the chances for survival of the already threatened desert tortoise. Ravens and coyotes are accomplished scavengers, but they are skilled hunters when they have to be, and with their numbers multiplying thanks to our discards, they now have turned increasingly to hunting.
There’s nothing new about animals picking up our scrap, as Conniff points out. On a trip to Yellowstone National Park in 1967, I remember the grizzly bears walking up and down lines of cars looking for handouts, and getting them. This activity, and the practice of dumping wastes behind Yellowstone’s lodges to attract the bears for a “show,” emboldened the bears and is thought to have led to some sensational maulings of campers—thus compelling the Park Service to prohibit those practices and remove “problem” bears. Turned out this policy was better for the bears, as they returned to a more natural diet and flourished.
It’s more a matter of volume today: Too much food waste subsidizing some opportunistic species that function well not only in the wild but on the edges of our world—or, like gulls, crows, and ravens, boldly and directly in our world—and thereby crowding out other species.
Of course, from our standpoint, there are reasons to reduce food waste that are more direct and beneficial than simply protecting other species. We can reduce our waste disposal costs and, through composting, provide valuable soil amendments for our gardens, among other things. Or we can help reduce hunger by redirecting surplus food supplies to food pantries. But just in case you needed another reason, we now have biodiversity concerns to consider.