Melting Glaciers Nourishing Oceans With Ancient Carbon


Glaciers that naturally melt each summer along the Gulf of Alaska flush out huge amounts of organic material, made up mostly of dead microbes.
Those microbes had feasted on ancient carbon from boggy forests, which lined the Alaska coast between 2,500 to 7,000 years ago and were later trapped under glaciers.

Once released via glacial melt, the dead microbes provide a tasty treat for living microbes, which are at the base of the marine food web, researchers say. (See map.)

Previous studies had shown that carbon from living forests eventually makes its way into fish through the water cycle, so “fish are made out of the forest,” said study leader Eran Hood, an environmental scientist at the University of Alaska Southeast in Juneau.

(Related: “Glacier ‘Bleeds’ Proof of Million-Year-Old Life-Forms.”)

The new study reveals “the same kind of thing—the fish are probably made out of carbon from glaciers,” Hood said. “This is a surprising thing we didn’t know before.”

Glacial melt may even have a hand in maintaining Gulf of Alaska fisheries, some of the most productive in the country, he added.

Giant Water Pump

The Gulf of Alaska drainage basin is a giant water pump: It includes more than 10 percent of the mountain glaciers on Earth, and annual runoff from the region produces the second largest discharge of fresh water into the Pacific Ocean.

Hood and colleagues analyzed organic matter in runoff from 11 coastal watersheds in 2008, during the annual peak of glacial melting.

The team sampled streams running through watersheds with different amounts of glacial coverage.

Watersheds with no glaciers at all would be expected to contain less meltwater, while those dominated by ice would be filled with glacial runoff.

What they found is that streams fed by glacial melt had a surprising amount of easily digestible, or “bioavailable,” carbon.

In addition, the more glacially rich the water, the older the carbon—up to 4,000 years old.

Glacial melt is seasonal—ice builds up during the winter and sloughs off in the summer. But rising temperatures have set off a worldwide thaw of many glaciers and ice sheets, which collectively act as the second largest reservoir of Earth’s fresh water, Hood said.

If glaciers continue to disintegrate due to climate change, an initial bounty of carbon released into the oceans would be followed by the complete loss of a major source of nutrients, he said.

Marine ecosystems are nourished by many sources other than glaciers, Hood added.

Ocean upwelling, for example, is a natural cycle in which cold water filled with nutrients rises from the seafloor, feeding surface life.

But a sudden influx of fresh water from melting ice could also disrupt the ocean currents that drive upwelling.

No Expiration Date

The new study goes against a long-held belief that older carbon is less palatable to simple organisms, Hood added.

For instance, in most of the world’s water bodies, the older the carbon, the less easily microbes can digest it.

“That’s the stuff that’s been worked over—it’s no good,” Hood said. “But in our case the older it was, the more the microbes wanted to eat it.”

That’s mainly because glacial carbon is made of dead microbes that have been essentially preserved in ice.

The dead microbes contain more easily digestible nitrogen and not much lignin, a plant compound that’s tough for microbes to break down.

Overall, the contribution of glaciers to the productivity of rivers and oceans is “greatly underappreciated,” the study authors write.

“It’s good to understand the uniqueness of glacier ecosystems and the important role that they play as a source of water and nutrients,” Hood added.

Courtesy:nationalgeographic

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How can you help?

How can you help?
The best way is to pay attention to how you are using water. Be careful not to waste it or pollute it.
One important thing each of us can do to conserve water is to not let the faucet run longer than necessary. For example, turn off the faucet while brushing your teeth. Then use a glass of water for rinsing your mouth. There’s no need to leave it running, so turn it off! If you notice a faucet is dripping, ask your parents to fix it.
With only 1 percent of water available to drink, there’s not a drop to waste!
Don’t use the toilet as a trash can. That wastes water and may pollute it, too. If you have chemicals, old medicines or anything else you aren’t sure whether it is safe to put into a toilet, ask an adult how to dispose of them properly.

Don’t take your water for granted

Don’t take your water for granted

Between 70 and 75 percent of the Earth’s surface is covered with water, but only 1 percent of all the world’s water can be used for drinking. Nearly 97 percent of the world’s water is salty or otherwise undrinkable. Another 2 percent is frozen in ice caps and glaciers, leaving only 1 percent to drink.
It is difficult and expensive for people to produce make more fresh water to drink, so each one of us needs to conserve our precious resource.

Courtesy:Department Of Environmental Protection

What are surface water cleanup plans?

Drinking water in a public water system is treated to make sure it is safe to drink before it enters all those pipes. Surface water treatment plants filter the water to remove particles of dirt, minerals, microorganisms and other stuff you wouldn’t want in your glass of water.
The water from public water systems using surface water or groundwater is then disinfected to kill dangerous germs. Chlorine is a chemical commonly used to disinfect water supplies.
Families that use their own drinking water wells have to make sure the water is clean and safe to drink.

Where does Drinking water comes from?

Drinking water begins its journey to homes, schools and businesses from either a surface water source or a groundwater source.
Surface water sources are streams, rivers and lakes. They are on the surface of the land and are exposed to the air, rain and water flowing downhill from land near the source.
Groundwater is in the ground, not on top of it. We pull it up from wells drilled into the ground. Most groundwater comes from rain and melting snow soaking into the ground. Water fills the spaces between rocks and soils, making an “aquifer.”
About half of our nation’s drinking water comes from ground water. Most is supplied through public drinking water systems, though many families rely on their own wells. On average, eight out of 10 Pennsylvania residents receive their water from public water systems.

What Can You do to Protect Your Watershed?

After that walk, I bet you have some good ideas on what you can do to protect your watershed!  Let’s name a few:
  • Always pick up after your pet!
  • Be aware of how much water you use. Think of ways to conserve!
  • Never throw trash on the ground. Make sure to put it in the trash, and remember to recycle when you can.
  • Convince your parents to drive less. Try to plan trips to the store, school and gas station or other places in the same area so you waste less gas and time. The shorter the trip, the less air pollution.
  • Ask you parents to wash the car in the yard, where suds can absorb into the soil, and water the grass all at the same time!
  • Tell your parents to never use fertilizer or other items with chemicals especially before it rains. Use natural fertilizers like manure, mulch, or compost.
  • Plant some trees or grass next to the stream in your watershed. These plants will help keep the dirt in place and out of the stream. They will also help catch some of the bad chemicals that can get washed into streams

Courtesy:Department Of  Environmental Protection

 

the susquehanna river watershed

Illustration of the Susquehanna River Basin
Now, let’s use the Susquehanna River as an example. ALL the water (from rain, melting snow, even sprinklers and hoses) that falls within the Susquehanna River watershed (no matter how far away from the river), will eventually travel all the way to the Susquehanna River. That means that everything that happens in the Susquehanna River Watershed has an impact on the river, and the Chesapeake Bay, too! This is because the Susquehanna River Watershed is part of the larger Chesapeake Bay Watersheds.