
Salmon Cannon Fires 40 Fish a Minute - jjp
http://www.cnet.com/uk/news/salmon-cannon-fires-40-fish-a-minute-up-to-22mph/
======
limaoscarjuliet
Reminds me of Chatham Island black robin conservation efforts that turned out
not so good:

[http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjourna...](http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0079066)

Conservation management often focuses on counteracting the adverse effects of
human activities on threatened populations. However, conservation measures may
unintentionally relax selection by allowing the ‘survival of the not-so-fit’,
increasing the risk of fixation of maladaptive traits. Here, we report such a
case in the critically-endangered Chatham Island black robin (Petroica
traversi) which, in 1980, was reduced to a single breeding pair. Following
this bottleneck, some females were observed to lay eggs on the rims of their
nests. Rim eggs left in place always failed to hatch. To expedite population
recovery, rim eggs were repositioned inside nests, yielding viable hatchlings.
Repositioning resulted in rapid growth of the black robin population, but by
1989 over 50% of all females were laying rim eggs. We used an exceptional,
species-wide pedigree to consider both recessive and dominant models of
inheritance over all plausible founder genotype combinations at a biallelic
and possibly sex-linked locus. The pattern of rim laying is best fitted as an
autosomal dominant Mendelian trait. Using a phenotype permutation test we
could also reject the null hypothesis of non-heritability for this trait in
favour of our best-fitting model of heritability. Data collected after
intervention ceased shows that the frequency of rim laying has strongly
declined, and that this trait is maladaptive. This episode yields an important
lesson for conservation biology: fixation of maladaptive traits could render
small threatened populations completely dependent on humans for reproduction,
irreversibly compromising the long term viability of populations humanity
seeks to conserve

~~~
bayesianhorse
I think the lesson should be: If a species is hovering over the brink of
extinction, it's a better idea to do whatever it takes and only worry about
the consequences later...

Of course, if rim-laying had been fixated, the species would still have become
extinct...

~~~
shostack
Or perhaps to dig deeper as to WHY they are on the brink of extinction. If
they develop a trait that causes them to lay their eggs on the rim (which can
be directly linked to the species decline), isn't that just Darwin at work?
Who are we to step in an say "yep, they're idiots for doing it, but we should
still save them."

~~~
bayesianhorse
Charles Darwin was a scientist, not a super-natural deity responsible for
evolution. He can't be "at work".

Extinction events for natural reasons shouldn't be as frequent. Otherwise
there would be far fewer species left. Therefore any extinction process we
witness, especially with a species starting out with a healthy population,
probably isn't natural.

------
arethuza
Transferring live fish by pipeline has been used in the fishing industry for a
long time - large trawlers will store fish in salt water in tanks and when
they get into port they are transferred by pipeline directly from the trawler
to the fish processing plant so they are still alive when they hit the table
where they are "processed".

[NB A fisherman explained this to me in Mallaig Scotland, none of the fishing
boats I've been on were so high tech!]

~~~
Gracana
I wonder if the tech is any different. If the fish are going to be slaughtered
shortly, then it wouldn't matter (ethics aside) if they're a little hurt in
the process, provided the meat isn't damaged, whereas here it is quite
important that the fish remain unharmed.

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ChuckMcM
I do not want to be there when the bears learn implicitly that salmon spring
from the end of the tube :-) But I love the concept.

~~~
coldcode
As a bear I will fall in love with the lunch tube.

~~~
yutah
some commercial fisheries will enjoy renting those too

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hudibras
This is Hyperloop's MVP.

~~~
fit2rule
Yeah, I was just thinking it'd be great to have a human-scale version of this
.. to get from one Soapy Land to another, perhaps?

~~~
kylek
Commuting to work by slip-and-slide sounds like a blast to me...!

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SinFulNard
I feel like this was the highlight;
[http://gfycat.com/SophisticatedFarawayEthiopianwolf](http://gfycat.com/SophisticatedFarawayEthiopianwolf)

~~~
Kiro
Sophisticated Faraway Ethiopian Wolf?

~~~
Terr_
It's an ID or hashcode, but in English words rather than hexadecimal.

Easier for humans to recall, communicate, and error-check.

~~~
ANTSANTS
An utter bitch to type compared to a short string of garbage, though, and
typing a URL manually (friend gives you a URL over the phone or in person) is
the only case I can think of where the URL itself matters.

~~~
vacri
On mobile, perhaps, where you're pecking at a keyboard like a chicken, but
with a keyboard it's easier to type.

~~~
Sambdala
I find it the opposite to be honest, but probably only because I'm using swype
on mobile.

It's easy to hit random characters when touch typing on a full keyboard, but
it's much easier to just swipe a couple words together in the url bar than it
is to get the correct capitalization as well as having to hold down the key
for about a second each time you need a number.

~~~
thaumasiotes
If I need a number, I just swipe down from the letter that the number appears
under. No press-and-hold needed. Does that not work on your phone?

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tombrossman
I wonder how this affects the fish's slime coating, which is important to
preserve. It seems like this would be rubbed off on the material as the fish
is propelled along the tube, no?

~~~
sjtrny
How do they get the coating in the first place? They create it of course. I'm
sure they can create more if this scrapes it away.

~~~
tombrossman
They can create more just as your body would create scar tissue if I scraped
some of your skin off. Meanwhile, the exposed area is far more likely to
become infected as your skin no longer protects it. Not a perfect analogy but
it illustrates my point well enough.

~~~
zizee
Since this is to help them on their final stage of their migration to the
spawning grounds (after spawning they die), I don't think infection is a big
issue.

~~~
Gravityloss
Not all salmon die after spawning.

~~~
Turing_Machine
All Pacific salmon (which is what these are) die after spawning. A few
Atlantic salmon (about 10%, ATW) will survive to make another trip.

The Pacific species basically start to decompose as soon as they hit fresh
water.

Once they've spawned, they fall apart like something out of a bad horror
movie. I've seen semi-alive fish that you could stick your thumb through
without any effort (usually snagged by a tourist who's proud of his
accomplishment).

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morganm
I recently watched DamNation [1] and was quite surprised at the shear number
of dams located in the United States. The film claims that most have outlived
their purpose. I can't recall the exact cost stated per fish to divert them
around dams or raise them in a hatchery, but it was fairly high. The film's
production quality was quite high and was fairly eye opening.

While doing a little googling, I found an article [2] claiming $7 million in
fish ladder work after structural damage forced a reduction in water level. So
perhaps this solution could be cost effective or quickly put in place in case
damage occurs just before a run.

[1] [http://damnationfilm.com/](http://damnationfilm.com/) [2]
[http://www.columbian.com/news/2014/apr/12/crack-in-dam-
force...](http://www.columbian.com/news/2014/apr/12/crack-in-dam-forces-
costly-fish-ladder-work/)

~~~
stevenrace
Per this comment, I checked out 'DamNation'. It was fascinating, thanks for
the recommendation.

The number quoted as $9,000/'Snakeriver Sockeye' that made the 800 mile
journey upstream to Redfish Lake, Idaho. In 1992, as they tell it, only one
fish made it. But that apparently was the first year after the project began.
Then again, only 243 made it 2011 [1]. Only ~1,500 made it back to Granite
lake, which is 400 miles upstream [2]. So it's part of a larger problem in the
area.

So the $40million spent equates to 222 fish per year on average.

I'm pretty sure the 'Fish Canon', however humane, can at least match the 1
fish every 36hrs rate of existing systems.

It's also worth noting the US Army Corp of Engineers ship large numbers of
juvenile fish downstream on barges. Collecting them with the 'Fish Cannon' and
then shipping them on barges back upstream (or furthest upstream lock) is just
a budget/politics problem not one of technology.

[1]
[http://seattletimes.com/html/localnews/2019705443_captivefis...](http://seattletimes.com/html/localnews/2019705443_captivefish18m.html)

[2] [http://www.bpa.gov/news/newsroom/Pages/Snake-River-
sockeye-c...](http://www.bpa.gov/news/newsroom/Pages/Snake-River-sockeye-
continue-upward-trend-in-2011.aspx)

------
ars
Watch only the second video, the first is terrible.

~~~
Gracana
Oh, I'm glad you said that. I didn't watch the second video because I didn't
expect it to be any better than the first, but it turns out it's way more
informative.

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cwal37
If you're interested in the current state of the US hydropower generation,
potential resource out there, and really most everything around hydropower in
the USA, check out the NHAAP website.

[http://nhaap.ornl.gov/](http://nhaap.ornl.gov/)

NHAAP is the National Hydropower Asset Assessment Program, and it's put
together a large chunk of the groundwork for the DOE's hydropower vision
project.

[http://energy.gov/eere/water/new-vision-united-states-
hydrop...](http://energy.gov/eere/water/new-vision-united-states-hydropower)

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alexissantos
In 20 Million Years...

"Our ancestors traveled the beige tube to new waters, while the two-legged
creatures watched and guided them."

~~~
Terr_
_Old_ waters. They return the waters of their birth.

Also, the storytellers die before their audience hatches...

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ASneakyFox
This would be crazy if fish start to understand the cannon. Use it on their
own and then continue on to find their destination (rather than be totally
lost and confused)

~~~
timje1
Unless I'm mistaken, the fish head upstream to die. None of them will
encounter the cannon twice, unless the same river has multiple dams on it.

~~~
JumpCrisscross
Similar to how the salmon "learned" to swim back to where they were born, the
increased survival frequency of salmon who can efficiently negotiate such a
cannon would be expected to change the population.

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freejack
I've just finished listening to a radio interview where the guest asserted
that technology and innovation is solely the domain of young white males
focused on social networking problems to make money for the benefit of
investors. I am so happy to have seen this on the heels of such a terrible
interview.

 _And_ I love the thinking that went into this invention. I really appreciate
the novel approach although I can't help but wonder how they've dealt with the
issue of friction and how that might affect the fish - I imagine that there's
a fair amount of heat created over such a long run, even at the relatively low
speeds described in the videos.

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lubos
Could this be used for humans? Looks like fun way to commute.

~~~
DLister
You mean kind of like the public pneumatic tube transport in futurama?

~~~
yen223
But with none of the comfort. Or safety.

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chrisBob
What attracts the fish to the tube? The ladders work by providing some water
that is going down stream slowly it is an obvious path. If there is no water
to swim upstream against I don't understand why a fish would enter a random
tube.

~~~
XaspR8d
At about 88 secs in the second video[1] they show the inside of some sort of
"trap" for the fish where water flows rapidly over a grate (and claim
"volitional entry"). But I agree it's still an open question whether you could
mitigate the fish's behavior effectively.

[1]
[https://www.youtube.com/watch?v=wSBS2F9VXaE#t=88](https://www.youtube.com/watch?v=wSBS2F9VXaE#t=88)

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ErikRogneby
This is a huge improvement on trucking them around the dams when the
reservoirs are too low for the fish ladders.

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gipp
How do they get back down?

~~~
jws
They don't. For salmon it is spawn and die. Their fry will come back down with
the water.

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jevgeni
I'm happy to live in these times.

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davidgerard
Science article headline of the year.

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anon4
I've watched all the videos and I still can't understand how that thing can
possibly work. They say it creates vacuum and transports things using
atmospheric pressure, but both ends of the tube are open! What vacuum are they
talking about? Is there a pump at one end sucking air? Am I looking at an
elaborate prank?

~~~
frandroid
[https://www.youtube.com/watch?feature=player_embedded&v=SDzJ...](https://www.youtube.com/watch?feature=player_embedded&v=SDzJbhOVm0Q#t=14)

Look at 0:14. This thing is put a little bit after the start of the pipe,
creating a draft. The fish's own body becomes the "plug" that this air pump
pushes up.

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ommunist
This device in its usefulness reminds me the squid gun of the infamous Vector
superhero from Despicable Me. Normal people build cascades around dams for
salmon. Once built these require zero maintenance.

~~~
awjr
I think for specific situations this can be useful. In the final video they
show a 'holding tank' the salmon eventually get to and are then hand
transported through the building to the next body of water.

I think it has been designed for a very specific commercial issue (maximising
the restocking of wild salmon). I'm guessing this has applications elsewhere
where you want to transport live fish/tubular slimy animals.

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nether
into my mouth

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Fragment
How long before this is a Minecraft mod?

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dsirijus
It's a good thing to get out of your comfort zone every once in a while.

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praptak
Here is a Cow Cannon, we can estimate its firing rate at 10 cows per second:
[https://www.youtube.com/watch?v=F8sMXp6zCl8#t=205](https://www.youtube.com/watch?v=F8sMXp6zCl8#t=205)

