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This is not a technology or IT related topic but it is more about how nature rejuvenates itself.
Source: https://www.nytimes.com/2017/01/19/...ml?smid=tw-nytimes&smtyp=cur&mtrref=t.co&_r=1
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A wall of ice filled with dead fish photographed in 2015 in South Dakota’s Lake Andes National Wildlife
The fish in this photo look as if they have frozen to death midjump. But what really happened is more complicated. And while it’s easy to feel sorry for the frozen fish and worry that something has gone terribly wrong, you can take comfort in the fact that their deaths were part of an ecological reboot for the lake where they died.
“Sometimes nature seems harsh, but it is all a part of the life cycle of a wetland,” Kelly Preheim, a kindergarten teacher and birder who first shot the photo last February, wrote in an email.
The National Wildlife Refuge System, part of the United States Fish and Wildlife Service, first shared the photo on its Facebook page as part of a picture captioning contest in December. But it received renewed attention this week after the Department of Interior shared it on Twitter.
Ms. Preheim was amazed to see a four-foot wall of frozen fish while birding in Lake Andes National Wildlife Refuge in South Dakota and said she had never heard of this phenomenon. But commenters on Facebook reported seeing something like it before. And in 2014, a man and his miniature schnauzer stumbled upon a whole school of frozen pollock along the surface of a bay in Norway. The man thought the fish had gotten trapped in the bay while trying to escape a predator, and then strong winds and freezing temperatures froze the fish in place.
But South Dakota’s “fishcicles” as Ms. Preheim calls them, offer up a slightly more complex story. According to an account she shared when the refuge posted her picture, the fish died in a lake depleted of oxygen.
In 2015, at the time the photo was taken, she said, the area around the lake had been suffering from a drought, and water levels were low. Thick ice formed on the lake’s surface that, along with snow cover, blocked sunlight and prevented algae and other aquatic plants from conducting photosynthesis. Without the plants’ converting carbon dioxide to oxygen, the oxygen levels dropped. Plants died and decomposed, depleting even more oxygen. And then the fish suffocated and died under the icy surface before floating to the top by the thousands.
The fish did not die by freezing midair.
There are two possible explanations for the wall of fish ice in the photo. One is that as the weather got colder, the ice expanded. It reached the shore, cracked, crumpled and shot upward, fish included. Or, it’s possible that strong winds alone pushed the frozen water and its fishy contents upward into an ice wall.
Hundreds of bald eagles and gulls feasted on the dead fish that year. But it wasn’t until a full year later that the full effects were seen: Wildlife had exploded around the lake, Ms. Preheim noted on her blog. According to Mick Hanan, a wildlife biologist at the refuge, this bloom of living things resulted because the drought provided a reset for the wetlands. The fish, which were overabundant and non-native, had thrown the whole system off balance. In their absence, nutrients recycled between the soil and water, the water cleared up and the remaining plants thrived in more sunlight. More plants meant more bugs, frogs, fish, snakes and birds that fed on them all.
And in case you were wondering, the winning caption was submitted by Adam Seymour, a follower of the refuge system’s Facebook page: “Can someone please hit the Play button?”
Source: https://www.nytimes.com/2017/01/19/...ml?smid=tw-nytimes&smtyp=cur&mtrref=t.co&_r=1
================================================
A wall of ice filled with dead fish photographed in 2015 in South Dakota’s Lake Andes National Wildlife
The fish in this photo look as if they have frozen to death midjump. But what really happened is more complicated. And while it’s easy to feel sorry for the frozen fish and worry that something has gone terribly wrong, you can take comfort in the fact that their deaths were part of an ecological reboot for the lake where they died.
“Sometimes nature seems harsh, but it is all a part of the life cycle of a wetland,” Kelly Preheim, a kindergarten teacher and birder who first shot the photo last February, wrote in an email.
The National Wildlife Refuge System, part of the United States Fish and Wildlife Service, first shared the photo on its Facebook page as part of a picture captioning contest in December. But it received renewed attention this week after the Department of Interior shared it on Twitter.
Ms. Preheim was amazed to see a four-foot wall of frozen fish while birding in Lake Andes National Wildlife Refuge in South Dakota and said she had never heard of this phenomenon. But commenters on Facebook reported seeing something like it before. And in 2014, a man and his miniature schnauzer stumbled upon a whole school of frozen pollock along the surface of a bay in Norway. The man thought the fish had gotten trapped in the bay while trying to escape a predator, and then strong winds and freezing temperatures froze the fish in place.
But South Dakota’s “fishcicles” as Ms. Preheim calls them, offer up a slightly more complex story. According to an account she shared when the refuge posted her picture, the fish died in a lake depleted of oxygen.
In 2015, at the time the photo was taken, she said, the area around the lake had been suffering from a drought, and water levels were low. Thick ice formed on the lake’s surface that, along with snow cover, blocked sunlight and prevented algae and other aquatic plants from conducting photosynthesis. Without the plants’ converting carbon dioxide to oxygen, the oxygen levels dropped. Plants died and decomposed, depleting even more oxygen. And then the fish suffocated and died under the icy surface before floating to the top by the thousands.
The fish did not die by freezing midair.
There are two possible explanations for the wall of fish ice in the photo. One is that as the weather got colder, the ice expanded. It reached the shore, cracked, crumpled and shot upward, fish included. Or, it’s possible that strong winds alone pushed the frozen water and its fishy contents upward into an ice wall.
Hundreds of bald eagles and gulls feasted on the dead fish that year. But it wasn’t until a full year later that the full effects were seen: Wildlife had exploded around the lake, Ms. Preheim noted on her blog. According to Mick Hanan, a wildlife biologist at the refuge, this bloom of living things resulted because the drought provided a reset for the wetlands. The fish, which were overabundant and non-native, had thrown the whole system off balance. In their absence, nutrients recycled between the soil and water, the water cleared up and the remaining plants thrived in more sunlight. More plants meant more bugs, frogs, fish, snakes and birds that fed on them all.
And in case you were wondering, the winning caption was submitted by Adam Seymour, a follower of the refuge system’s Facebook page: “Can someone please hit the Play button?”
