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. raven

    Ouch you guys! I never worry too much about punctuation and spacing too much . What I do worry about is getting my point across. Right now I feel kinda sad but my point is this: I dont want people resenting ME cuz of what OTHERS are doing WITH my name and TO my name .

    April 1, 2011 at 12:44 am | Report abuse |
  2. fake raven, fake jazz, fake dave, et al

    thank you for apologizing. I have enjoyed impersonating you folks. Spent my day off convulsing in laughter at your reactions. Why? Well, I have, in fact been irritated by your lengthy (nearly incessant) personal conversations. While you often begin with a somewhat cogent comment in reference to the relevant story, you usually digress into chit-chat amongst yourselves. You might appreciate that there are more appropriate venues for that. No malice intended. Consider it an early April Fool's prank and please forgive me for upsetting your applecart. Adieu.

    April 1, 2011 at 1:00 am | Report abuse |
  3. david

    Lots of dead fish

    April 1, 2011 at 1:15 am | Report abuse |
  4. Enco

    Hey david what's up bi_ch?

    April 1, 2011 at 1:17 am | Report abuse |
  5. david

    Work work work. Tax is here so fast too.

    April 1, 2011 at 1:19 am | Report abuse |
  6. enco

    Got a refund, $380

    April 1, 2011 at 1:21 am | Report abuse |
  7. Mohamad

    Lucky you. I am having to pay over $200 this year.

    April 1, 2011 at 1:23 am | Report abuse |
  8. Hurst

    Lol I'm working my taxes right now along with a warm cup of chocolate. Its still a little cold in Maine.

    April 1, 2011 at 1:26 am | Report abuse |
  9. raven

    Well if there was no malice why not just use your own name ? Its pretty hypocritical to say you were annoyed by our chit chat yet you took an awful lot of time,space and effort that couldve been used to post your own thoughts under your own name relating to the topic. I may digress but i dont think i incessantly chit chat. My apology was sincere yours just sounds like a condescending segue into a way to show everyone how clever you think you are. Im sorry I irritated you that much, you could have just told me instead of trying to humiliate me .

    April 1, 2011 at 1:29 am | Report abuse |
  10. Chrissy

    Lol I love hot chocolate. I always put 3 marsh mellows on top.

    April 1, 2011 at 1:32 am | Report abuse |
  11. Cesar r

    Hey raven join the party. Forget about that troll the guy probably doesn't have a life anyway.

    April 1, 2011 at 1:34 am | Report abuse |
  12. banasy

    3 marsh mellows. I use 6.

    April 1, 2011 at 1:36 am | Report abuse |
  13. jj

    I wish the marsh mellows would last longer. They melt so quickly.

    April 1, 2011 at 1:38 am | Report abuse |
  14. Linda

    I like vanilla coffee

    April 1, 2011 at 1:41 am | Report abuse |
  15. faker

    You humiliate yourself, Raven. You will notice I "humiliated" a lot of people, not just you. True, my apology was sent with a smirk. I enjoyed myself; I won't lie. If you people weren't so pre-occupied with yourselves you might have noticed the many attempts made by many posters to get you to understand that this a BLOG, a PUBLIC forum. No place for conversation off topic. This is not a chat room. You deserved what everyone else got from you. I have nothing for which to apologize.

    April 1, 2011 at 1:42 am | Report abuse |
1 2 3 4 5 6 7 8