Gulf mammal deaths likely far higher than body count, scientists say
A NOAA Fisheries Service graphic illustrates the sharp rise in Gulf of Mexico dolphin deaths that began even before the oil spill.
March 31st, 2011
02:43 PM ET

Gulf mammal deaths likely far higher than body count, scientists say

For every dead dolphin or whale that washes up on Gulf Coast beaches, there may be 50 more that no one ever sees, a new study suggests.

Natural factors and last year's oil spill in the Gulf of Mexico probably have caused thousands more dolphin and whale deaths than have been observed, a team of scientists says in a study published Wednesday by the journal Conservation Letters.

The scientists, led by Rob Williams, said 101 cetacean, or marine mammal, carcasses had been observed in the water or on beaches as of the time of their study.

After analyzing historical data on populations and death rates of 14 species in the northern Gulf, the scientists determined that carcasses are found in only 2% of cetacean deaths.

"Thus, the true death toll could be 50 times the number of carcasses recovered, given no additional information," they write, adding that they don't know what the true figure is.

The scientists urge environmentalists and authorities not to rely solely on observed carcass counts in judging the severity of an event, but to develop standard formulas for more accurate estimates.

Scientists and observers have been alarmed by the high number of dead baby and preterm dolphins that washed ashore in February during the first calving season since the spill.

The National Oceanic and Atmospheric Administration's Fisheries Service counted 36 infant dolphin strandings in February; there was just one in February 2010, and the 2002-2007 average for February is 2.2. Stranding is the scientific term for marine mammals that end up on land.

NOAA had noticed a rise in cetacean deaths even before the spill which resulted from an April 20 explosion and fire on the Deepwater Horizon oil rig that killed 11 workers.

"We have been monitoring an increase of dolphin deaths in the northern Gulf since February of 2010," NOAA Fisheries spokeswoman Karrie Carnes said.

The numbers of stranded (dead or alive) dolphins and whales are shocking: Against a 2002-07 average of 31.4 for January through March, there were 76 for that period in 2010 and 139 in 2011, according to NOAA.

Scientists aren't jumping to conclusions about what's killing the animals. Similar "unusual mortality events" occur from time to time; the Gulf has seen 13 of them since 1991, said Blair Mase, NOAA's lead marine mammal stranding coordinator. Marine mammals are particularly susceptible to harmful algal blooms, infectious diseases, temperature and environmental changes, and human impact, she said.

"Frankly, it's just too early to tell at this point," Mase said in February. "It's obviously on everyone's radar screen. Everyone's concerned about any impact of the BP oil spill, but we have to be very cautious as to identify any particular cause. We won't know until we have these samples analyzed and be able to identify the source."

soundoff (117 Responses)
  1. Gbagbo

    If you tell me one thing about her that I don't already know, I will tell you two. Then I will go away. I will not bother her, Spock, or you. Just one thing. Just don't lie. That's the main rule.

    March 31, 2011 at 7:46 pm | Report abuse |
  2. Gbagbo

    David TIME 7:32. You're fake.

    March 31, 2011 at 7:49 pm | Report abuse |
  3. ferret


    March 31, 2011 at 7:55 pm | Report abuse |
  4. Gbagbo

    Deals off david. Ill see you saturday. Ill have a different name. One clue: it will start with an E. I wonder what name you will have, LIAR.

    March 31, 2011 at 7:59 pm | Report abuse |
  5. ferret


    March 31, 2011 at 8:51 pm | Report abuse |
  6. L64

    Hi ferret.

    March 31, 2011 at 10:41 pm | Report abuse |
  7. ryan

    What a bunch of losers you are... thought CNN might actually be the place to read intellectual opinions rather than this shizz. Fukk all you retards, guess I will join in...

    March 31, 2011 at 10:43 pm | Report abuse |
  8. david

    I don't think you can join us. Your knot stupid enough ryan

    March 31, 2011 at 11:04 pm | Report abuse |
  9. JAZZ

    No Ryan join us , we need someone to keep us all in check , NOT

    April 1, 2011 at 12:03 am | Report abuse |
  10. raven

    This is me ,the real raven . I apologise to all posters and readers, And to the hijackers and silly people throwing my name around: its not just me youre affecting ,there are others who use this forum whom im sure are beginning to resent ME because of what YOURE doing. Im sure you have some legitimate thoughts to post on the TOPICS?? Please stop tossing my name around and hijackin it.and again to other readers,apologies all around .

    April 1, 2011 at 12:04 am | Report abuse |
  11. Brad


    April 1, 2011 at 12:05 am | Report abuse |
  12. Jacob

    Be quiet fake raven. The real raven has better grammar than you meat head. What a loser and a fake. The real raven is asleep right now. She is so sweet. I love most of her opinions.

    April 1, 2011 at 12:12 am | Report abuse |
  13. raven

    Lol, Jacob! Im flattered but this really is me ! I just scanned all the posts and saw how much my names bein used. I can only imagine how irritating it must be for legit posters and readers to have to scroll thru all the junk just to post . As for my grammar,well,what can I say? I sound like a meat head ??ouch!! But thanks for the other,kind things you said,thats nice to hear and i look forward to readin your opinions too .

    April 1, 2011 at 12:23 am | Report abuse |
  14. Gary

    The real raven is low profile and bright. This fake can't even spell apologize. The true raven has a good head on her shoulder. Few posts, but enough to gauge that sweet little gal. The fake raven can't even space her words correctly or punctuate. lmao

    April 1, 2011 at 12:23 am | Report abuse |
  15. Jacob

    Gary I bet it's a guy. At least he is harmless no verbal attacks or profanity. He must get a rise out of getting peoples' attention. Get a life dude.

    April 1, 2011 at 12:29 am | Report abuse |
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