The future is here, and it's not pretty
By now I think we've all heard various stories of impending environmental doom. Stories like "Humans are causing mass extinctions," "Coral reefs are dying," and "All the world's fisheries will collapse by 2050" are commonplace in the news, but at the same time it is quite easy to shrug those things off as something that will happen in the future. Sadly, I think the future is now.
Sea lions have been called the canary in the coal mine that is our ocean. They are an important sentinel species as they inhabit the same coastal areas, prey on the same types of fish, and contract the same diseases as many people. And now they're dying--what does this mean?
California sea lions (Zalophus californianus) are found along the western coast of the U.S. and Mexico, with a subspecies (Zalophus californianus wollebacki) found in the Galapagos, and number about 200,000. During the summer of 2009, The Marine Mammal Center rescued 1698 animals, approximately 1400 of which were California sea lions. That number is three times the number of animals rescued in an average year.
Why were we swamped with sea lions? Because they were starving to death. I don't have an exact number handy, but I'd estimate that at least 1000 of the animals we rescued were yearlings. Pregnant sea lions give birth in June, and before doing so they will "kick out" the previous year's pup, leaving it to fend on its own. But this past summer there were no fish to be found, and the yearling pups began starving and dying by the thousands. For awhile, you couldn't go to a central California beach and not see at least one dead sea lion.
It wasn't just the yearlings that were starving; newborn pups in two Southern California rookeries experienced a mortality rate of more than 28% (normal mortality rate is 6%), and at least two species of cormorant--Brandt's and Double-crested--experienced significant starvation events during Summer 2009 as well.
So, why are there no fish for these animals to eat? Where did the fish go? The National Marine Fisheries Service (NMFS) reported a "disruption in the coastal upwelling process off central and northern California during May and June" which would have affected nutrient distribution, and therefore the entire food web. Basically, small prey fish would have moved off in search of food, and larger predators (fish, birds, and marine mammals alike) would normally follow them. But small, inexperienced, comparatively weak yearling sea lions and nursing mothers were unable to travel far out to sea in search of food and thus could not eat.
There's also the issue of overfishing. It is a well-known fact that fisheries around the world are in decline, and some major fisheries have already collapsed. Close to home, the herring fishery in San Francisco Bay was closed by the state Fish and Game Commission this past September. Herring are a major prey species for sea lions, and local fishermen are saying there are none around. The truth is, upwellings or not, there just aren't as many fish out there in the oceans as people might think.
As if that wasn't enough, San Francisco's famed sea lion colony at Pier 39 has vanished. A record 1701 animals were counted on the Pier October 23rd, 20 were there on November 28th, and today there are between zero and 6. Some tagged animals were reported to have travelled south to the Monterey Bay area, while others were said to have moved north to Oregon. It is highly suspected that the animals moved away in search of food.
So, in case you're wondering what the death of the oceans is going to look like, well, open your eyes. We're watching the beginning of the largest extinction event of the past 65 million years. Hang on; it's going to be a rough ride.
Sea lions have been called the canary in the coal mine that is our ocean. They are an important sentinel species as they inhabit the same coastal areas, prey on the same types of fish, and contract the same diseases as many people. And now they're dying--what does this mean?
California sea lions (Zalophus californianus) are found along the western coast of the U.S. and Mexico, with a subspecies (Zalophus californianus wollebacki) found in the Galapagos, and number about 200,000. During the summer of 2009, The Marine Mammal Center rescued 1698 animals, approximately 1400 of which were California sea lions. That number is three times the number of animals rescued in an average year.
Why were we swamped with sea lions? Because they were starving to death. I don't have an exact number handy, but I'd estimate that at least 1000 of the animals we rescued were yearlings. Pregnant sea lions give birth in June, and before doing so they will "kick out" the previous year's pup, leaving it to fend on its own. But this past summer there were no fish to be found, and the yearling pups began starving and dying by the thousands. For awhile, you couldn't go to a central California beach and not see at least one dead sea lion.
It wasn't just the yearlings that were starving; newborn pups in two Southern California rookeries experienced a mortality rate of more than 28% (normal mortality rate is 6%), and at least two species of cormorant--Brandt's and Double-crested--experienced significant starvation events during Summer 2009 as well.
So, why are there no fish for these animals to eat? Where did the fish go? The National Marine Fisheries Service (NMFS) reported a "disruption in the coastal upwelling process off central and northern California during May and June" which would have affected nutrient distribution, and therefore the entire food web. Basically, small prey fish would have moved off in search of food, and larger predators (fish, birds, and marine mammals alike) would normally follow them. But small, inexperienced, comparatively weak yearling sea lions and nursing mothers were unable to travel far out to sea in search of food and thus could not eat.
There's also the issue of overfishing. It is a well-known fact that fisheries around the world are in decline, and some major fisheries have already collapsed. Close to home, the herring fishery in San Francisco Bay was closed by the state Fish and Game Commission this past September. Herring are a major prey species for sea lions, and local fishermen are saying there are none around. The truth is, upwellings or not, there just aren't as many fish out there in the oceans as people might think.
As if that wasn't enough, San Francisco's famed sea lion colony at Pier 39 has vanished. A record 1701 animals were counted on the Pier October 23rd, 20 were there on November 28th, and today there are between zero and 6. Some tagged animals were reported to have travelled south to the Monterey Bay area, while others were said to have moved north to Oregon. It is highly suspected that the animals moved away in search of food.
So, in case you're wondering what the death of the oceans is going to look like, well, open your eyes. We're watching the beginning of the largest extinction event of the past 65 million years. Hang on; it's going to be a rough ride.