More recent penguin research documents the bio-accumulation of organic pollutants in the soil of Adelie Penguin colonies. As reported in the Journal of Environmental Monitoring, the authors found concentrations of persistent organic pollutants such as DDT, DDE, and PCB's 10 to 100 times higher in soils of penguin colonies than in nearby reference areas. Although these pollutants have been known in penguins, where they bio-accumulate from pollutants distributed to the Antarctic through long-range atmospheric transport from other areas, this research suggests that these birds further bio-accumulate these pollutants at their colonies through defecation. Thus, the soils around the penguin colonies are "hot spots" of persistent organic pollutants.
Other penguin items of note include this National Geographic video here with a couple of brief shots of yours truly counting penguins. This video is from two years ago when Boyd Matson accompanied us on the National Geographic Endeavour and it includes a number of the Oceanites researchers in the video. It is a fairly good if not brief overview on the current status of penguins on the Antarctic Peninsula.
Oh yeah, and one more thing. Those penguins that are occasionally reported off the Pacific coast of North America are probably unwilling hitchhikers from farther south. An article by A. N. Van Buren and P. Dee Boersma in the Wilson Journal of Ornithology examined the occurrences of penguins north of the equator (excluding the Galapagos Penguin which nests on Isabella Island in the Galapagos just north of the line). Although penguins are known to move very long distances (I once found a Magellanic Penguin, which normally breeds in southern South America, near Palmer Station on the Antarctic Peninsula), these movements are all within cold or cold waters of the southern hemisphere. They argue against natural vagrancy for the northern observations because a penguin would likely overheat in the equatorial waters before finding cold waters north of the equator.
The authors explain that the occurrences of these birds is probably due to intentional capture and subsequent release by fishermen moving from the cold southern waters to the cold northern waters and provide information on a number of penguins found on fishing vessels in northern waters.
Laurence Roosens, Nico Van Den Brink, Martin Riddle, Ronny Blust, Hugo Neelsa and Adrian Covaci. 2007. Penguin colonies as secondary sources of contamination with persistent organic pollutants. Journal of Environmental Monitoring 9 pp. 822-825.
A. N. Van Buren and P. Dee Boersma. 2007. Humbolt Penguins (Spheniscus humbolti) in the Northern Hemisphere. The Wilson Journal of Ornithology 119(2)284-288.