Showing posts tagged as "salmon"
A Sad Anniversary—and a Cautionary Tale for Our Oceans
By Jim Covel, Director of Guest Experience
September 1 marked the 100th anniversary of the death of the last passenger pigeon. Named “Martha,” this bird has the dubious distinction of being an “endling,” meaning she was the very last of her species. Martha spent most of her estimated 29 years at the Cincinnati Zoo in one of the first captive breeding programs, which was ultimately unsuccessful.
What makes Martha’s story so remarkable—and regrettable—is that a century earlier the number of passenger pigeons in North America was estimated as high as 3-5 billion birds! The flocks depended on large tracts of hardwood forest for food, nesting and roosting areas. One nesting area in Wisconsin was estimated at 850 square miles hosting over 130,000,000 passenger pigeons. Migrating flocks would darken the skies for hours or days at a time.
Despite those unimaginable numbers, in less than 100 years only Martha remained—and then there were none. Unregulated commercial hunting wiped out one flock after another. The bird’s habit of consistently returning to the same areas facilitated the slaughter. Removing vast tracts of forest that were essential habitat for the passenger pigeon put the final nail in the species coffin.
In retrospect, Martha and her kind provided an awful awakening that we humans had the power to drive nearly any species over the precipice into extinction. Martha inspired a new round of conservation measures that limited and eventually eliminated many forms of commercial hunting. It would be nice to know that we learned that lesson well. But have we?
Passenger Pigeons of the Ocean?
If we look to the sea rather than the sky, there are fishes that might be considered the passenger pigeons of the ocean—species once so abundant their numbers were considered both inestimable and inexhaustible. The great runs of salmon on our Pacific Coast might be one example. Most major rivers along this coast supported runs of salmon ranging from the hundreds of thousands to over 10 million in the Columbia River. These fish were concentrated into defined spawning runs, much like the passenger pigeons occupied specific nesting and roosting areas. Early fishers could row from shore placing large seine nets around the salmon and then using teams of horses to drag the laden nets up onto shore.
Yet today many salmon runs are considered endangered. Commercial salmon fishing is highly regulated as is sport fishing, so why are salmon numbers still in trouble? The quality of salmon habitat—particularly spawning streams and rivers—continues to decline. Just as farmland replaced the extensive hardwood forests the passenger pigeons relied upon, human demands for fresh water leave less and less available in streams for the fish. A universal truth in nature is that any species is only as healthy as the habitat it depends upon.
So if we work toward healthy oceans and healthy streams, perhaps we can enjoy healthy populations of many important fishes well into the future. The very thought that someday there could be an “endling” coho salmon, or bluefin tuna is too terrible to contemplate. Remember Martha, and as we acknowledge her regrettable anniversary we can renew our commitment to prevent similar tragedies in the future.
Learn more about conservation at the Aquarium
(Image from Smithsonian Institution Archives)
Can you find her? One of the Chinook salmon in the Monterey Bay Habitats exhibit is undergoing the typical changes that precede spawning. These fish live to about about four years old and display these changes, such as the traditional hooked jaw, at the end of their lifespan.