Slashdot Mirror

← Back to Stories (view on slashdot.org)

Restoring Salmon To Their Original Habitat -- With a Cannon

Posted by timothy on from the going-up? dept.

StartsWithABang writes Hydroelectric dams are one of the best and oldest sources of green, renewable energy, but — as the Three Gorges Dam in China exemplifies — they often cause a host of environmental and ecological problems and challenges. One of the more interesting ones is how to coax fish upstream in the face of these herculean walls that can often span more than 500 feet in height. While fish ladders might be a solution for some of the smaller dams, they're limited in application and success. Could Whooshh Innovations' Salmon Cannon, a pneumatic tube capable of launching fish up-and-over these dams, finally restore the Columbia River salmon to their original habitats?

14 of 147 comments (clear)

  1. just a little bigger... by Anonymous Coward · · Score: 4, Funny

    Then we can have a shark cannon... that will attach lasers to their heads ... And put bees in their mouths.

    The cold war with Russia is back baby!

    1. Re:just a little bigger... by fuzzyfuzzyfungus · · Score: 5, Funny

      What about a rail gun salmon launcher? After they mate they are completely spent and become zombie fish. Hardly edible.

      The engineering considerations surrounding such a device seem formidable indeed. Most of the data available are for humans(who, shockingly enough, have most of the medical budget dedicated to measuring delicate electrical signals through their muscle tissue); but if we assume that salmon tissue is approximately similar to human muscle, at least for the purposes of the currents and voltages a railgun implies, we can conclude that (A) the math is obnoxious. (B) fish are shitty conductors (C) fish have other obnoxious properties like 'capacitance' and non-homogenous conductivity.

      Given the substantial resistance of our pisciform projectile, and the railgun's need for heroically high peak currents, supply voltage will have to be quite high, introducing additional insulation challenges, risks of air-gap breakdown between the rails, damaging arcs in other areas of the apparatus, and so on. Further issues may arise because of the projectile's non-uniform conductivity and substantial fluid content: with current flow, and resistive heating, highest along the most conductive regions, the projectile may exhibit substantial internal deformation, or even catastrophic loss of structural integrity, during acceleration or at a very early stage of flight. While it may have valuable specialty applications, this so-called 'frangible fish' effect markedly reduces effective range and almost entirely precludes survival of the projectile.

      It is conceivable that advances in Aquatic-Preservation Discarding Sabot technology will allow a suitably packaged salmon to successfully traverse the accelerator rails while retaining the buoyancy necessary for continued survival by discarding the conductive jacket before entry into the target body of water. However, such developments are presently theoretical and cannot form the basis of a viable ecological dominance capability in the near term.

  2. Pet Peeve by Jane+Q.+Public · · Score: 5, Insightful

    I get pretty pissed off when people say that hydroelectric power is "cheap" or "free" or "clean" energy, or that all the money to build the dams came from the Federal government so everyone should enjoy the benefits.

    It DOES have ongoing costs to people who live in the region, and they aren't small. While some recreational activities are created, others are lost, so that's a zero-sum. But then there are the other ecological costs: loss of fish and fisheries for many thousands of square (not to mention linear) miles of waterway. There is the loss of land behind the dam which was often (perhaps typically) farmland. And so on.

    There are many other factors: wildlife typically will no longer migrate across the reservoir, leading to loss of habitat. Etc. etc.

    It ain't free, and people in the region do pay for it.

    1. Re:Pet Peeve by Anonymous Coward · · Score: 5, Interesting

      Would these be the inflated waste storage costs paid to store the waste in the least safe and most expensive manner possible because the anti-nuclear lobby has campaigned to prevent the nuclear industry from storing the waste in the sensible places they originally intended to?

      Also, hydroelectric doesn't scale. Need twice as much energy? Too bad, there's only so much flow through the river and only so many places where it can be sensibly dammed up. Meanwhile, nuclear scales nicely.

      "But at least there aren't meltdowns..."

      Ever seen a dam break? Look up the number of casualties due to dam breaks in the last 50 years vs the number of casualties due to nuclear meltdowns in the last 50 years. Then divide by watts.

    2. Re:Pet Peeve by art6217 · · Score: 5, Informative
      Charles Darwin, The Origin of Species:

      When ducks suddenly emerge from a pond covered with duck-weed, I have twice seen these little plants adhering to their backs; and it has happened to me, in removing a little duck-weed from one aquarium to another, that I have unintentionally stocked the one with fresh-water shells from the other. But another agency is perhaps more effectual: I suspended the feet of a duck in an aquarium, where many ova of fresh-water shells were hatching; and I found that numbers of the extremely minute and just-hatched shells crawled on the feet, and clung to them so firmly that when taken out of the water they could not be jarred off, though at a somewhat more advanced age they would voluntarily drop off. These just-hatched molluscs, though aquatic in their nature, survived on the duck's feet, in damp air, from twelve to twenty hours; and in this length of time a duck or heron might fly at least six or seven hundred miles, and if blown across the sea to an oceanic island, or to any other distant point, would be sure to alight on a pool or rivulet.

  3. They are pussies by Tablizer · · Score: 5, Funny

    Can't they just evolve and grow legs to hike up? We did it, dammit!

    --
    Table-ized A.I.
  4. Shoot, it's worth a try by penguinoid · · Score: 5, Funny

    Q: What did the fish say when it bumped into a concrete wall?
    A: Dam!

    --
    Don't waste your vote! Vote for whoever you want, unless you live in a swing state it won't matter anyways
  5. It's not just a fish cannon. by SuricouRaven · · Score: 4, Funny

    It's an eagle entertainment device.

    1. Re:It's not just a fish cannon. by istartedi · · Score: 5, Funny

      It's an eagle entertainment device.

      This bears watching to see what happens.

      --
      For all intensive purposes, "whom" is no longer a word. That begs the question, "who cares"?
  6. Incidentally... by fuzzyfuzzyfungus · · Score: 5, Interesting

    I cannot independently confirm the truth of this; but I was told, in all apparent seriousness, by someone I know well and who I know to have a long association with the hydroelectric generation business, that the term for what happens to a fish that fails to avoid the turbine intakes is "turbine induced stress". As one might imagine, this 'stress' tends toward the lethal end of the spectrum.

  7. But it's safe! by thegarbz · · Score: 5, Informative

    But Hydroelectric is incredibly safe when you look at all other forms of energy production. It certainly has never displaced as many people or killed as many people as nuclear.

    Oh wait!

    The halo effect describes cognitive bias people have about others based on an impression. It applies to industry just as much as it applies to people. Look at the full lifecycle cost of anything and nothing is really without issues, especially hydroelectric power which currently wins top prize as worst accident by death toll ever though the Chinese government list it as a natural disaster.

  8. Re:that gets the salmon upstream... by Half-pint+HAL · · Score: 5, Informative

    Actually, the problem is indeed the downstream trip, but not like that. A fish heading downstream naturally navigates towards the fastest flowing water channel... which in this case is the turbine intake.

    --
    Got them moderator blues I blieve I walk out the do', With these mod-points I been gettin', I 'most never post no mo'
  9. Do the calculations by sjbe · · Score: 5, Insightful

    I haven't performed the calculations behind it but I have a sneaking suspicion that it's cheaper than nuclear power

    Then do the calculations before spouting off publicly and anonymously about it.

  10. Salmon by sjbe · · Score: 4, Insightful

    it's clean because using the power produces no big emissions(apart from manufacturing replacement parts).

    Emissions are not the only type of pollution that matters. Hydro dams mess up ecosystems rather badly in a lot of cases. They might be the least worst alternative but "clean" in this case is only a relative term. They are certainly not consequence free.

    also the thing with salmon is tha wild salmon from the rivers wouldn't fill the supermarkets anyways - it's just a sport... a niche sport.

    Salmon serve ecological purposes beyond simply occupying space in grocery stores and providing entertainment for fishermen. Salmon are important parts of food chains and dams tend to interrupt this food chain with sometimes serious consequences.