Dam Aliens

Fight disinformation: Sign up for the free Mother Jones Daily newsletter and follow the news that matters.


600px-Volta_lake.jpg Freshwater ecosystems are losing even more species than
terrestrial or marine environments. Why? Because of dams. More than 80,000 major dams and 2.5 million smaller
reservoirs have altered natural hydrology across the U.S. The result: nearly 1,000 introduced species disrupting native aquatic systems.

The study published in the September Frontiers in Ecology
and the Environment
concludes that dam construction and biological invasions are closely linked, reports Environmental Science & Technology.

A University of Colorado Boulder team analyzed conditions in 4200 natural lakes and 1081 impoundments in Wisconsin and Michigan. They looked at five widespread nuisance species: Eurasian water milfoil (Myriophyllum spicatum), zebra mussel (Dreissena polymorpha), spiny water flea (Bythotrephes longimanus), rainbow smelt (Osmerus mordax), and rusty crayfish (Orconectes rusticus).

Species were 2.4 to 7.8 times more likely to occur in dammed water bodies than in natural lakes. Reservoirs were significantly more prone to hosting multiple non-natives. Boaters and fishers are the unwitting coyotes smuggling in the aliens. Zebra mussels attach to boat bottoms. Milfoil plants clings to boat trailers. Smelt and crayfish used to be used as bait, though that’s now illegal.

Of course the troubles with dams don’t end there. Some large dammed areas become major greenhouse gas emitters (though in all fairness hydroelectric plants are way cleaner than coal). Many dams disrupt fish breeding cycles. Many large dams submerge unique ecosystems and/or human cultures and artifacts. Some superlarge dams and their lakes may stress load earthquake faults.

Just to make things even weirder, there are now plans to log a Ghanaian forest submerged by the Akosombo Dam that created Lake Volta nearly 50 years ago. Old-growth, rot-resistant hardwood trees like ebony, wawa, and odum are still in excellent shape underwater, reports ENN. The project is led by a privately owned Canadian company, CSR Developments. They aim to harvest 1500 million cubic feet of timber worth about $4 billion. They estimated there are 12 million acres of salvageable submerged tropical timber in hydroelectric reservoirs.

Ideally the underwater harvet would help slow deforestation on land and curb emissions of greenhouse gases linked to burning of forests.

Stay tuned.

Julia Whitty is Mother Jones’ environmental correspondent, lecturer, and 2008 winner of the Kiriyama Prize and the John Burroughs Medal Award.

WE'LL BE BLUNT

It is astonishingly hard keeping a newsroom afloat these days, and we need to raise $253,000 in online donations quickly, by October 7.

The short of it: Last year, we had to cut $1 million from our budget so we could have any chance of breaking even by the time our fiscal year ended in June. And despite a huge rally from so many of you leading up to the deadline, we still came up a bit short on the whole. We can’t let that happen again. We have no wiggle room to begin with, and now we have a hole to dig out of.

Readers also told us to just give it to you straight when we need to ask for your support, and seeing how matter-of-factly explaining our inner workings, our challenges and finances, can bring more of you in has been a real silver lining. So our online membership lead, Brian, lays it all out for you in his personal, insider account (that literally puts his skin in the game!) of how urgent things are right now.

The upshot: Being able to rally $253,000 in donations over these next few weeks is vitally important simply because it is the number that keeps us right on track, helping make sure we don't end up with a bigger gap than can be filled again, helping us avoid any significant (and knowable) cash-flow crunches for now. We used to be more nonchalant about coming up short this time of year, thinking we can make it by the time June rolls around. Not anymore.

Because the in-depth journalism on underreported beats and unique perspectives on the daily news you turn to Mother Jones for is only possible because readers fund us. Corporations and powerful people with deep pockets will never sustain the type of journalism we exist to do. The only investors who won’t let independent, investigative journalism down are the people who actually care about its future—you.

And we need readers to show up for us big time—again.

Getting just 10 percent of the people who care enough about our work to be reading this blurb to part with a few bucks would be utterly transformative for us, and that's very much what we need to keep charging hard in this financially uncertain, high-stakes year.

If you can right now, please support the journalism you get from Mother Jones with a donation at whatever amount works for you. And please do it now, before you move on to whatever you're about to do next and think maybe you'll get to it later, because every gift matters and we really need to see a strong response if we're going to raise the $253,000 we need in less than three weeks.

payment methods

WE'LL BE BLUNT

It is astonishingly hard keeping a newsroom afloat these days, and we need to raise $253,000 in online donations quickly, by October 7.

The short of it: Last year, we had to cut $1 million from our budget so we could have any chance of breaking even by the time our fiscal year ended in June. And despite a huge rally from so many of you leading up to the deadline, we still came up a bit short on the whole. We can’t let that happen again. We have no wiggle room to begin with, and now we have a hole to dig out of.

Readers also told us to just give it to you straight when we need to ask for your support, and seeing how matter-of-factly explaining our inner workings, our challenges and finances, can bring more of you in has been a real silver lining. So our online membership lead, Brian, lays it all out for you in his personal, insider account (that literally puts his skin in the game!) of how urgent things are right now.

The upshot: Being able to rally $253,000 in donations over these next few weeks is vitally important simply because it is the number that keeps us right on track, helping make sure we don't end up with a bigger gap than can be filled again, helping us avoid any significant (and knowable) cash-flow crunches for now. We used to be more nonchalant about coming up short this time of year, thinking we can make it by the time June rolls around. Not anymore.

Because the in-depth journalism on underreported beats and unique perspectives on the daily news you turn to Mother Jones for is only possible because readers fund us. Corporations and powerful people with deep pockets will never sustain the type of journalism we exist to do. The only investors who won’t let independent, investigative journalism down are the people who actually care about its future—you.

And we need readers to show up for us big time—again.

Getting just 10 percent of the people who care enough about our work to be reading this blurb to part with a few bucks would be utterly transformative for us, and that's very much what we need to keep charging hard in this financially uncertain, high-stakes year.

If you can right now, please support the journalism you get from Mother Jones with a donation at whatever amount works for you. And please do it now, before you move on to whatever you're about to do next and think maybe you'll get to it later, because every gift matters and we really need to see a strong response if we're going to raise the $253,000 we need in less than three weeks.

payment methods

We Recommend

Latest

Sign up for our free newsletter

Subscribe to the Mother Jones Daily to have our top stories delivered directly to your inbox.

Get our award-winning magazine

Save big on a full year of investigations, ideas, and insights.

Subscribe

Support our journalism

Help Mother Jones' reporters dig deep with a tax-deductible donation.

Donate