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Fish Tagged For Research Become Lunch For Gray Seals

Posted by Soulskill on from the earned-a-seal-of-approval dept.

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.

48 comments

  1. Well Tell Me Grey Seal How Does It Feel by Anonymous Coward · · Score: 0

    To be so wise?

  2. Seems pretty benign by EzInKy · · Score: 2

    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.
    1. Re:Seems pretty benign by Thanshin · · Score: 0

      Humans have been manipulating the evolution of other lifeforms for hundreds of thousands of years or more already.

      Humans have been doing for hundreds of thousands of years a lot of things that in modern society are frowned upon. Like, for example, eating people.

    2. Re:Seems pretty benign by Anonymous Coward · · Score: 2, Insightful

      The problem isn't the impact it has on the ecosystem, it is that the test results can become skewed by the monitored fish becomes easier to catch.

    3. Re:Seems pretty benign by Flavianoep · · Score: 1

      It's not benign to the research.

      --
      Linux is for people who don't mind RTFM.
    4. Re:Seems pretty benign by happy_place · · Score: 1

      I wonder if true fish population counts might be skewed, if the ones being monitored are all being eaten. It would show that fish populations are smaller than they really are. Which could affect local fisheries and conflate environmental impact concerns.

      --
      http://www.beanleafpress.com
    5. Re:Seems pretty benign by vikingpower · · Score: 1

      People taste great. I was once offered the forearm of a human being in Port Moresby. With curry sauce. Yum.

      --
      Religous speak to God. Insane are spoken to by God. When all shut up, one can finally hear Shostakovich in peace
  3. Fair chance by muttoj · · Score: 2

    Equip the fish with lasers to even the odds.

  4. So you use Radio instead, eh? by Anonymous Coward · · Score: 0

    It doesn't take a scientist to figure out that you shouldn't tag fish with tracking devices that seals can hear. Unless of course your grant money is paid by the same corporation that makes the tracking devices, and you're a bottom feeding scum sucking pathetic excuse for a scientist.

    1. Re:So you use Radio instead, eh? by meerling · · Score: 1

      Seals are very adept at finding an easy meal.
      I take it those particular researchers have never studied seals before. :)

    2. Re:So you use Radio instead, eh? by Zembar · · Score: 1

      It doesn't take a scientist to know that radio doesn't work well underwater either.

    3. Re:So you use Radio instead, eh? by gmarsh · · Score: 3, Informative

      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.

    4. Re:So you use Radio instead, eh? by Anonymous Coward · · Score: 0

      Exactly and only 69kHz? No distortion / harmonics? (From the emitter or the environment itself.)

    5. Re:So you use Radio instead, eh? by gmarsh · · Score: 1

      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.

    6. Re:So you use Radio instead, eh? by JesseMcDonald · · Score: 1

      ... 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
    7. Re: So you use Radio instead, eh? by gmarsh · · Score: 1

      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.

    8. Re:So you use Radio instead, eh? by Anonymous Coward · · Score: 0

      These are acoustic tags. But Vemco makes radio telemetry tags as well. They work OK.

  5. Gray Seals by Thanshin · · Score: 0

    Maybe that's what happened to Osama.

  6. It ain't the seals that are wise ... by Anonymous Coward · · Score: 0, Troll

    ... it be the humans are idiots

    Tagging somethings which give out audible sounds especially those somethings are natural foodstuffs for other animals are akin to telling the world "I am here, come eat me"

    1. Re:It ain't the seals that are wise ... by Thanshin · · Score: 2

      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

    2. Re:It ain't the seals that are wise ... by TapeCutter · · Score: 2

      -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.
    3. Re:It ain't the seals that are wise ... by beh · · Score: 1

      Apparently, if you understand the seal's dialect, you'll clearly hear them say:

      So long, and thanks for all the fish!

  7. it figures by marcello_dl · · Score: 2

    -[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
    1. Re:it figures by Anonymous Coward · · Score: 0

      You bastards! You killed Kenny!

  8. Easy solution for the scientists by yo303 · · Score: 2

    Change the scope of to study to be the migration patterns of seals who are good at finding pinging fish.

  9. The solution by Anonymous Coward · · Score: 0

    The solution to this is to end cruelty to animals. There is no conclusive evidence that scientific research on animals yields meaningful results for human welfare. We constantly hear the corporatist oligarchs saying how human medicine would not exist without animal research, and that is total and utter bullshit. These people just get a cheap thrill out of convincing government that animal research is needed, taking millions in taxpayer money, and using in to torture and kill innocent animals for their own sick amusement.

    1. Re:The solution by Muros · · Score: 1

      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.

    2. Re:The solution by Anonymous Coward · · Score: 0

      Or maybe research on scientists that do research on animals. We should fund both the research on animals and the research on scientists until we get this burning question answered!

  10. Get rid of those evil seals by Anonymous Coward · · Score: 1

    First they screw the penguins, and now they eat our fish.

    What next?

    1. Re:Get rid of those evil seals by PPH · · Score: 1

      What next?

      Is your bicycle locked up?

      --
      Have gnu, will travel.
    2. Re:Get rid of those evil seals by fredrated · · Score: 1

      What, seals can ride bikes now?

  11. Protocol issues by Anonymous Coward · · Score: 0

    Sounds like they need to stop those fish responding to ICMP echo requests from all and sundry. You can't just stick a fish on a public network and assume that seals aren't going to ping it for reconnaissance. I'd suggest using some kind of port knocking.

  12. Seals are Bastards by Anonymous Coward · · Score: 0

    http://www.dailymail.co.uk/sciencetech/article-2839233/The-shocking-photographs-revealed-seals-having-sex-penguins-sparked-international-furore.html

    1. Re:Seals are Bastards by BarbaraHudson · · Score: 1

      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.
  13. based on what a girl once told me by argStyopa · · Score: 1

    Maybe it's just polite foreplay?

    http://www.dailymail.co.uk/sci...

    --
    -Styopa
  14. Re:Easy solution for the scientists^Polar Bears by BarbaraHudson · · Score: 3, Interesting

    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.
  15. Better than Sea Lions by squiggleslash · · Score: 1

    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.
  16. With the rate the fishing industry is collapsing by Anonymous Coward · · Score: 0

    With the rate the fishing industry is collapsing nothing here is going to matter much. Every time one fish type is collapsed and we(the people) put a much to late restriction on them, the fleets move to another type of fish and work fast on killing that species all off.

    http://en.wikipedia.org/wiki/Collapse_of_the_Atlantic_northwest_cod_fishery

  17. Observer effect by The+Grim+Reefer · · Score: 2

    It is meaningful in all kinds of ways.

  18. Re:Easy solution for the scientists^Polar Bears by Anonymous Coward · · Score: 0

    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.

    Are you SURE polar bears are in serious decline?

    Global population of polar bears has increased by 2,650-5,700 since 2001

    IUCN Polar Bear Specialist Group says its global population estimate was “a qualified guess”

  19. so use negative reinforcement by milkmage · · Score: 1

    attach the pingers to sharks and orcas too.

  20. Are any of these fish researchers named "Pavlov"? by idontgno · · Score: 1

    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.
  21. Re:Easy solution for the scientists^Polar Bears by tlhIngan · · Score: 1

    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.

    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.

    The problem isn't the impact it has on the ecosystem, it is that the test results can become skewed by the monitored fish becomes easier to catch.

    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.

  22. Re:Easy solution for the scientists^Polar Bears by yo303 · · Score: 1

    Are you SURE polar bears are in serious decline?

    This sounds suspiciously like something a seal would say.

  23. Re:Easy solution for the scientists^Polar Bears by Anonymous Coward · · Score: 0

    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.

    Are you SURE polar bears are in serious decline?

    Global population of polar bears has increased by 2,650-5,700 since 2001

    IUCN Polar Bear Specialist Group says its global population estimate was “a qualified guess”

    Yes

  24. Re:Easy solution for the scientists^Polar Bears by Anonymous Coward · · Score: 0

    Al Gore showed a picture of a dead polar bear, so they must be in serious decline.

  25. Re:Easy solution for the scientists^Polar Bears by Anonymous Coward · · Score: 0

    Al Gore showed a picture of a dead polar bear, so they must be in super cereal decline.

    FTFY

  26. Just like using bells on hikers by Anonymous Coward · · Score: 0

    Just like using bells on hikers so the grizzly bears know where to find them