Encouraging seabirds to recolonize regions of the Channel Islands National Park in California requires more than just erecting artificial nests and hoping they’ll return. They also need native island flora and the sweet serenade from their own species resonating above sheer, volcanic cliffs.
Photo by Chuck Graham
Since 2008, the National Park Service has been aggressively restoring lost habitat for seafaring birds like the nocturnal ashy storm petrels and the seafaring Cassin’s auklets on Santa Barbara Island, and on large rock outcroppings like Orizaba Rock, but especially on Scorpion Rock near the southeast end of Santa Cruz Island.
The project has been funded by the Montrose Restoration Program, which oversees the restoration of natural resources in southern California marine environment that were harmed by DDT and PCBs. From the late 1940s to the early 1970s, Montrose Chemical Corporation’s DDT manufacturing plant in Torrance, CA, dumped millions of tons of DDT-contaminated wastewater in the Southern California Bight near Catalina Island. The results were devastating for the pelagic food web. Ocean sediments in the region now contain the largest known concentration of DDT in the world.
In March 2001, following 25 years of litigation, Montrose and three other corporations — that were manufacturing PCBs and releasing their waste into the ocean through the same channels as Montrose — were ordered to pay $140 million in restitution with $40 million going towards restoring natural resources like seabird colonies on the Channel Islands National Park.
Photo by Chuck Graham
Twelve species of seabirds nest on the archipelago. Besides Cassin’s auklets and ashy storm petrels, the other 10 species include double-crested, pelagic, and Brandt’s cormorants, pigeon guillemots, Scripps’s murrelets, California brown pelicans, western gulls, black oystercatchers, and two more types of petrels, black and leach’s. Eight of those species utilize Scorpion Rock, which is nearing the end of a major facelift, botanically speaking.
At one time or another all five islands that make up the Channel Islands National Park experienced ranching, mainly between the 1830s and the late 1980s. When non-native animals are brought to islands non-native plants also come along. Perpetual northwest winds blew seeds onto the islands’ rock outcroppings, including Scorpion Rock. The result was invasive crystalline ice plant, cheesehead, and goosefoot colonizing the offshore rock. Now, after years of stripping Scorpion Rock of the nonnative flora, restoration ecologist Dave Mazurkiewicz is winning the battle against the invasives on the wave-battered rock outcropping. Along with a slew of volunteers, the restoration team have removed about eight tons of the nonnative plants from the volcanic crag and at the same time planted 18 species of native island flora.
Photo by Chuck Graham
“The ice plant crystallizes and salt drips on the ground not allowing native plants to germinate,” explained Mazurkiewicz who works with the Montrose Restoration Program. “The ice plant physically blocks access for Cassin’s auklets, the only seabird on the islands that burrows into the ground to nest.”
Currently, about 35 breeding pairs of auklets nest inside artificial and natural burrows, while Mazurkiewicz and volunteers landscape the seabird guano-cloaked Scorpion Rock with coreopsis, sea blithe, alkali heath, California saltbush, prickly pear, Santa Cruz Island buckwheat and other native plants. The restoration team keeps a small nursery of native island flora on Santa Cruz Island and paddles them by kayak out to Scorpion Rock for planting. The laborious effort is paying off though and Mazurkiewicz sees a light at the end of the tunnel.
“It’s simply staying on top of the new plantings and monitoring nest sites,” he says of the work at hand now.
Photo by Chuck Graham
The biggest challenge facing the restoration process has been water. It’s been 7 years between significantly wet winters with 2010 being the last notable rainfall. That was until this winter. As of January, the island had already received over 10 inches of rain, good news for island flora gaining a foothold on Scorpion Rock. Earlier, rain totals were lean, the National Park Service had been transporting up to 1200 gallons of water per year to the island by boat. They would fill drums of water on Scorpion Rock and water the new plantings.
“We need one more big push next year,” says Mazurkiewicz. “You can’t just throw plants in the ground. Ideally it’s 10 years. Five years on the ground effort, then going into maintenance mode.”
On Scorpion Rock and Orizaba Rock, seven miles to its west, and Santa Barbara Island 40 miles to its south, social stimulation has encouraged the return of Cassin’s auklets and ashy storm petrels. To enhance colonization, biologists have used solar panels to power up MP3 players to broadcast the weak, croaking songs of the Cassin’s auklet that becomes a mighty chorus on windy, foggy nights. The audio broadcasts of the ashy storm petrel’s rising and falling vocals attracts petrels to potential nest sites on Orizaba Rock and the windswept cliffs on Santa Barbara Island.
“There’s been an increase in the number of nests,” says Laurie Harvey, a former seabird biologist for the Montrose Restoration Program. “Seabirds need habitat and no outside disturbances, but they also need social stimulation.”
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