Upon being notified by the California Department of Fish and Game (CDFG) and U.S. Coast Guard of the November 7th Cosco Busan spill, USFWS worked with all our partners to implement our "Heightened Awareness" protocols. PRBO's island staff followed procedures that guide response actions whenever an oiling event affects island wildlife. Daily, they searched areas on shore and scanned surrounding waters from island vantage points, for evidence of oil or oiled birds. Concurrently, the Coast Guard, NOAA, and others involved with the response made periodic overflights to look for oil that could be moving out to sea and threatening the islands. Luckily, no oil was confirmed to have reached the Refuge, although water samples were collected and sent in to authorities for analysis.
|A PRBO field biologist scans the water and land at Southeast Farallon Island. PRBO photo|
At the time of year when the Cosco Busan spill occurred, Common Murres—one of the seabird species most frequently oiled—land in their colonies only occasionally, as part of their natural pre-breeding behavior. On the few days that they made landfall, we detected that 10% or less were very lightly oiled on their breast feathers. These birds were still very mobile—and situated on steep, inaccessible rocks—making intensive capture-and-rescue efforts impossible.
PRBO surveyed around Southeast Farallon by boat when the weather permitted, trying to detect whether any swimming birds had oil on them and could be captured. Oiled individuals, most with a few spots on the breast, were difficult to distinguish from healthy birds on the water and were still very active. For lightly oiled birds, we determined that capture was virtually impossible and came with unacceptable risks. A few heavily oiled live seabirds were picked up around the Farallones and brought to the San Francisco Bay Oiled Wildlife Care and Education Center in Cordelia.
Daily communication took place among PRBO biologists on the island, myself, CDFG, the Oiled Wildlife Care Network, and others involved in Cosco Busan wildlife operations. We chose a course of action with consideration for the island's unique sensitivity. In a large seabird colony such as the Farallones, even when accessibility is not an issue, one must weigh the benefits of taking injured or sick birds into rehab against the costs of disturbing nearby healthy birds, which make up the bulk of the colony. Seabirds such as murres choose to nest on secluded islands to avoid human disturbance and predators, and the habitats they nest in are easily damaged.