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. david

    Thanks fake dave

    March 31, 2011 at 5:57 pm | Report abuse |
  2. Gbagbo

    Unga maronga, stay in ferret hungawa mangawa.

    March 31, 2011 at 6:00 pm | Report abuse |
  3. david

    @gbagbo.. This is a private fukkin conversation you motherfukker stay in your cage

    March 31, 2011 at 6:03 pm | Report abuse |
  4. raven

    is that really you david? I think now maybe its YOU faking posts.

    March 31, 2011 at 6:04 pm | Report abuse |
  5. ThomasD

    Thats a good question, Mama. How can you fairly judge a disaster and effectively fine without first knowing all long term effects?

    March 31, 2011 at 6:04 pm | Report abuse |
  6. david

    Wow fake dave, take it easy

    March 31, 2011 at 6:04 pm | Report abuse |
  7. david

    It wasn't me real david, I think there's another fukker

    March 31, 2011 at 6:06 pm | Report abuse |
  8. Gbagbo

    Shut up david you cheat on your girl. Shut up raven you cheat on your boyfriend. I should be your boyfriend raven. I can love you so much. I will treat you like a queen.

    March 31, 2011 at 6:10 pm | Report abuse |
  9. ferret

    mah friend morgan says i Gorra mouth like a motor boat da brain is fast but da mouth is always first

    March 31, 2011 at 6:13 pm | Report abuse |
  10. Gbagbo

    raven,david is blog-tarded. Do you read what he posts? I should be your on-line boyfriend. I will let you keep your real boyfriend.

    March 31, 2011 at 6:15 pm | Report abuse |
  11. david

    Hey ferret, we told you to stay out you asholl, go fukk your mama

    March 31, 2011 at 6:16 pm | Report abuse |
  12. Gbagbo

    raven, ok true ferret is a tad dumber than david but both are well below average. I-Q about 35-50. I am 38 years old raven. How old are you cup cake.

    March 31, 2011 at 6:19 pm | Report abuse |
  13. david

    raven has a yeast infection, bagboy

    March 31, 2011 at 6:21 pm | Report abuse |
  14. david

    Hey stupid ass that's not raven, the raven you're talking to is a man, maybe you will like his dikk

    March 31, 2011 at 6:25 pm | Report abuse |
  15. Gbagbo

    How would you know. You just want raven all for yourself you swine david

    March 31, 2011 at 6:26 pm | Report abuse |
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