Bay Area Bird Blog

Last week I wrote a little item pointing out that bird deaths in the recent SF Bay oil spill were probably greatly understated.  A correspondent wrote in with a mildly dissenting view.  (You might want to take a look at the original blog post and the comments).  The correspondent and I also exchanged a few thoughts about rescuing birds and other wildlife: it takes a huge amount of effort and expense, and lots of the birds/animals die anyway, so maybe it would be better to use the effort money in other ways?  Or maybe it wouldn’t: for one thing, it may not be a choice between “have volunteers put in thousands of hours rescuing birds” and “have volunteers put in thousand of hours doing something else.” Instead, it might be a choice between “have volunteers rescue birds” and not having volunteers available at all.

Anyway, the correspondent (who I call that because I don’t know what CWilson stands for) mentioned a Commentary by J.A. Estes in 1991 in the journal Science, that looks at some data from the Exxon Valdez oil spill in Alaska back in 1989.   Specifically, the commentary considers sea otters.  Here are some numbers, taken from the commentary:

1.  The Exxon Valdez spilled more than 10 million gallons of crude oil.
2. The oil spread over about 700 kilometers as the crow flies, and soiled about 5300 km of shoreline.
3. 878 sea otter carcasses were found, but “many animals killed by the spill undoubtedly were not found.”  (According to the commentary, “data suggest that only about one in five” were found). 
4. 357 sea otters were captured and taken to rehab facilities.
5. 123 sea otters died in captivity.
6. 37 were deemed unsuitable for release and transferred to aquaria; 12 died within 10 months.
7. The remaining 197 survivors were released.  
8. 45 of them carried surgically implanted radios. 22 of these — almost exactly half — were dead within 8 months. 
9. 61 of the 357 captured sea otters were found to be uncontaminated. 
10. Rescue efforts can contribute to mortality because “otherwise healthy sea otters suffer a 5 to 10% stress-induced mortality rate under the best of circumstances.”
11. Capture and rehab costs for the sea otters were $18 million.  That means the costs were at least $80,000 per animal rehabilitated, counting every otter that survived long enough to be released or to be sent to an aquarium).  

The commentary asks, “If a species or population is not threatened with decimation or extinction by [an] event, and if methods are not available to protect and rehabilitate affected wildlife, should the time, money, and anguish be put forth to save a few individuals”?  

Many people will have a gut reaction that OF COURSE it is worth it, we have to pay whatever it takes to try to put things right, etc. But the “it’s worth any price” argument can never really be right: no one could seriously argue that we should pay, say, $10 million to rehabilitate each sea otter. To me, the discussion isn’t about whether it’s worth paying to rehabilitate sea otters: the answer is clearly Yes at $500 per otter and clearly No at $1 million per otter. The tough part is figuring out where to draw the line in between!