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Fish Tagged For Research Become Lunch For Gray Seals
sciencehabit writes: When scientists slap an acoustic tag on a fish, they may be inadvertently helping seals find their next meal. The tags — rods a few centimeters long that give off a ping that can be detected from up to a kilometer away — are often used to follow fish for studies on their migration, hunting, or survival rates. Researchers working with 10 gray seals (Halichoerus grypus) who were captive for a year have now reported that the animals can learn to associate the pings with food. If the findings hold true in the wild, the authors warn, they could skew the results of studies trying to analyze fish survival rates or predation.
Humans have been manipulating the evolution of other lifeforms for hundreds of thousands of years or more already. Perhaps mostly inadvertantly, but our effect is nonetheless there. The trick here would be ensure that only the furriest seals benefit from this technology.
Time is what keeps everything from happening all at once.
Equip the fish with lasers to even the odds.
Seals are very adept at finding an easy meal. :)
I take it those particular researchers have never studied seals before.
It doesn't take a scientist to know that radio doesn't work well underwater either.
-[Seal] Give me a ping, fish, one ping only....
-[TAG] PING
-[Fish] WTF again?!?!
-[Seal] GULP
-[Humans] Damn, we lost another one... oh well, back to youporn.
---- MISSING MISCELLANEOUS DATA SEGMENT --- [sigdash] trolololol
Let me help you a bit further:
Why's it never light on my lawn?
Why did it rain and never say good day to the newborn?
On the big screen they showed us a sun
But not as bright in life as the real one
It's never quite the same as the real one
And tell me, grey seal
How does it feel to be so wise?
To see through eyes that only see what's real
Tell me, grey seal
I never learned why meteors were formed
I only farmed in schools that were so worn and torn
If anyone can cry then so can I
I read books and draw life from the eye
All my life is drawings from the eye
And tell me, grey seal
How does it feel to be so wise?
To see through eyes that only see what's real
Tell me, grey seal
Your mission bells were wrought by ancient men
The roots were formed by twisted roots
Your roots were twisted then
I was reborn before all life could die
The phoenix bird will leave this world to fly
If the phoenix bird can fly, then so can I
And tell me, grey seal
How does it feel to be so wise?
To see through eyes that only see what's real
Tell me, grey seal
Change the scope of to study to be the migration patterns of seals who are good at finding pinging fish.
First they screw the penguins, and now they eat our fish.
What next?
-Engage Scottish Accent -
Just one ping! We don't want to be mobbed by hungry seals.
And did you exchange a walk on part in the war for a lead role in a cage? - Pink Floyd.
Maybe it's just polite foreplay?
http://www.dailymail.co.uk/sci...
-Styopa
Radio waves don't travel well underwater. You need stupidly low frequencies like those used for submarine communication, and you won't be able to generate those frequencies from an object that's a few cm long which means you're stuck with acoustic methods. The tags in question operate at 69KHz, which as far as I know is outside the hearing range of seals - this article makes me wonder though, I've got it bookmarked and I'll give the underlying paper a good read when I've got the time.
I'm actually an engineer at the company that makes the tags in question. We're hardly a huge corporation (100 people) and we don't have the financial clout or even any obvious reason to bankroll corrupt science - we just make scientific gear that helps scientists do their science. I wouldn't consider us to be much different from a company that makes lab coats or glassware.
Now that we've solved the problem of feeding seals, let's tag those seals so that polar bears (who are in serious decline) can get their share.
"Transparent" is a shit show that trades on every stereotype going. A man in drag is NOT a transsexual.
There is no conclusive evidence that scientific research on animals yields meaningful results for human welfare.
We need more research on animals to test this.
I guess we can count ourselves lucky it was seals fouling up the experiment, at least they leave and don't mess up the surveys even more, unlike those damned sea lions.
You are not alone. This is not normal. None of this is normal.
Apparently, if you understand the seal's dialect, you'll clearly hear them say:
So long, and thanks for all the fish!
It is meaningful in all kinds of ways.
Pretty disgusting, but not all that surprising. Ever had a dog hump your leg? Or heard of these idiots having sex with a porcupine? Or a moose trying to get it on with a lawn ornament? And lots of stories of moose in love with cows. And dogs mating with cats ...
"Transparent" is a shit show that trades on every stereotype going. A man in drag is NOT a transsexual.
Going higher than 69KHz reduces the range of the tags, as higher frequencies are attenuated more in water. This means you'll need a more powerful tag (with size/battery life implications) or more deployed receivers to make the system work at a higher frequency.
The tags do produce harmonics at 138KHz/207KHz/onwards, but there's no distortion mechanism present that should allow frequencies lower than 69KHz to be created. There's no modulation done on the 69KHz carrier, the carrier is on/off keyed with time differences from one ping to the next being used to encode the tag's unique ID.
attach the pingers to sharks and orcas too.
Maybe he's not a fish research. Maybe he's a seal behaviorist. Or maybe he wants the cute seals to stay well fed.
Welcome to the Panopticon. Used to be a prison, now it's your home.
Not unless the seals get through the orcas first. (In the Pacific Northwest, there are two types of orca pods - "resident" and "transient". One of them pretty much eats just fish, the other, seals. If you go whale watching at the right time, you can see them catch seals. It's a rather organized affair - if the seal is on a floating object, the orcas bump into said object to send the seals flying (literally) through the air.
Seals also have adapted to humans - they know a fishing boat from a regular one, and will often try to steal fish from a fishing boat. There's a video where a seal swims behind a fishing boat, and the fisherman opens a hatch on the side of the boat, and you see the seal jump onto the boat.
Seals also often get close to regular boats where there are orcas around in an attempt to hide from said whales or seeking protection.
A Heisenbug! The act of observation changes the result. (Often confused with the Heisenberg Uncertainty Principle even by Heisenberg himself, when the actual name is Observer Effect). In this case, observing the fish changes the result because those tags are now appealing to seals.
Are you SURE polar bears are in serious decline?
This sounds suspiciously like something a seal would say.
... there's no distortion mechanism present that should allow frequencies lower than 69KHz to be created. There's no modulation done on the 69KHz carrier, the carrier is on/off keyed ...
No signal which carries information can be perfectly distortion-free. Just switching the carrier on and off is a form of modulation (akin to a continuous wave RF transmitter), with a bandwidth dependent on just how quickly the amplitude is switched, which is related in turn to the maximum rate of data transmission. This can easily result in signal components below the carrier frequency.
However, a quick search suggests that harbor seals respond to frequencies as high as 180 kHz in water (with a peak sensitivity around 32 kHz), so they may well be able to hear the tags' carrier frequency directly.
"The state is that great fiction by which everyone tries to live at the expense of everyone else." - Bastiat
True. The ping frequency is low though (hundreds of ms between pings) which limits the modulation sidelobes, and even the initial banging on of the carrier at the beginning of each ping is fairly well bandpass filtered by the high Q of the transmitter. You can't hear a tag click/chirp/whatever if you hold it against your ear.
But if seals can detect upwards of 180khz as you're saying... Yeah, that's a problem.