[MARMAM] oil spills and cetaceans

marmamed at uvic.ca marmamed at uvic.ca
Fri Jul 9 10:31:02 PDT 2010

>From Craig Matkin (comatkin at gmail.com)

Although the ongoing oil spill in the Gulf of Mexico is larger and may
have more complex effects on the environment than the *Exxon Valdez* oil
spill,  the potential for similar impact on cetaceans is very real.  I was
intimately involved in studying the damages following of the *Exxon
Valdez* spill in Alaska and have published a recent paper on the long term
effects on killer whales. (see link at
www.whalesalaska.org/publications.htm and abstract below). Unfortunately
in a spill of any size, the great majority of the oil cannot be cleaned up
no matter how large or numerous the skimmers. Although we cannot stand by
and due nothing, the idea that a significant amount of the oil can be
recovered is fallacy.   Prevention is the only rational approach and must
be taken extremely seriously. Cetaceans do not avoid oil, they are not
equipped to deal with large oil slicks of any size, and their chances for
deadly respiratory exposure can be high.

I am extremely saddened when I consider all the humans and animal's that
are dealing with the aftermath of this continuing spill. Our greatest
hope from the Gulf of Mexico disaster is that regulations and oversight on
oil production and transportation are seriously strengthened as they were
for oil transport in Prince William Sound following the *Exxon Valdez* .
Additionally the Minerals Management Service must revamped to serve the
interests of the public rather than the oil industry. Finally a
comprehensive energy policy that weans us from our need to continue these
dangerous drilling practices is essential.

*Ongoing population-level impacts on killer whales Orcinus orca following
the 'Exxon Valdez' oil spill in Prince William Sound, Alaska*

*C. O. Matkin, E. L. Saulitis, G. M. Ellis, P. Olesiuk, S. D. Rice*

Marine Ecology Progress Series 356:269-281.

ABSTRACT: Killer whales were photographed in oil after the 1989 Exxon
Valdez oil spill, but preliminary damage assessments did not definitively
link mortalities to the spill and could not evaluate recovery. In this
study, photo-identification methods were used to monitor 2 killer whale
populations 5 yr prior to and for 16 yr after the spill. One resident pod,
the AB Pod, and one transient population, the AT1 Group, suffered losses
of 33 and 41%, respectively, in the year following the spill. Sixteen
years after 1989, AB Pod had not recovered to pre-spill numbers. Moreover,
its rate of increase was significantly less than that of other resident
pods that did not decline at the time of the spill. The AT1 Group, which
lost 9 members following the spill, continued to decline and is now listed
as depleted under the Marine Mammal Protection Act. Although there may be
other contributing factors, the loss of AT1 individuals, including
reproductive-age females, accelerated the population's trajectory toward
extinction. The synchronous losses of unprecedented numbers of killer
whales from 2 ecologically and genetically separate groups and the absence
of other obvious perturbations strengthens the link between the
mortalities and lack of recovery, and the Exxon Valdez oil spill.

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