In an effort to keep more than 30 rare species of plants and animals from vanishing in Channel Islands National Park, federal biologists are developing a new strategy to protect the native flora and fauna before it’s too late.
Scientists from the U. S. Fish and Wildlife Service and Channel Islands National Park are crafting a conservation agreement designed to prevent further decline of the native species on four of the park’s northernmost islands.
As the plan is being developed, officials are considering removing or restricting some livestock and game animals that had been placed on the islands, and eventually weeding out non-native plants. Biologists may also nurture native species with some plantings.
A similar plan is being developed for the four southern Channel Islands by Fish and Wildlife’s office in Carlsbad.
Much of the disturbance on the islands has been caused by grazing and browsing of game animals imported for hunters or livestock, including cattle, elk, deer, pigs and sheep, said Connie Rutherford, a botanist heading up the agreement development for Fish and Wildlife.
While most of the large grazing animals have already been removed from Anacapa and San Miguel islands, the other two islands covered by the conservation agreement, Santa Cruz and Santa Rosa, still host the large grazers.
The animals denude rare shrubs and disrupt top soil with their hoofs, allowing the more aggressive invasive plants and weeds to crowd out native grasses and plants, she said. That reduces the vegetation available to native animals as well.
“In a couple of decades, you can undo what nature took thousands of years to create,” Rutherford said. “Putting the pieces back together is not so easy.”
The new conservation plan will try to take a broader look at protecting species than the government has taken in the past.
“This is a much more comprehensive approach,” Rutherford said of the conservation agreement. “We’re looking at the whole habitat or the whole ecosystem rather than just isolated portions of it.”
The developing agreement reflects the U. S. Department of Interior’s new direction for implementing the 20-year-old Endangered Species Act, which comes up for congressional reauthorization this year.
Interior Secretary Bruce Babbitt has instructed the Fish and Wildlife Service to avoid “train wrecks” and “crisis management” in part through conservation agreements among agencies overseeing public lands. Those agreements should help protect habitat and preclude the need for placing species on the endangered list, the department said.
When completed next year, the Channel Islands National Park conservation agreement should prevent species from becoming extinct.
“All plants and animals have a value in nature, and we don’t want to take the risk of causing the extinction of a species before we know what the value is,” Rutherford said.
Among the measures considered for the agreement include sparking controlled fires or selective use of herbicides to rid the islands of some weeds introduced by Europeans in the last century. Officials are also thinking about re-vegetation programs to bring back the native plants, using fences to keep non-native animals out of certain areas or restricting grazing to certain times of the year critical to plant growth.
But eliminating non-native grazing animals is by far the most important measure to preserve native species, Rutherford said. “Those animals are the main concern,” she said.
The conservation agreement could call for gradually scaling back the ranching operation on Santa Rosa Island, where Vail & Vickers Co. runs about 4,500 head of cattle, said C. Mack Shaver, superintendent of Channel Islands National Park.
The company also has a herd of 100 elk and 100 deer, which may be hunted for a fee.
But Shaver disputed that the grazing animals are an immediate threat to native species of plants and animals.
“Before we change radically the grazing on Santa Rosa, we need to understand those problems to be sure we don’t end up with a worse problem than we started with,” he said.
Shaver referred to an unexpected problem that arose on Santa Cruz Island when the Nature Conservancy, which owns 90% of the island, pulled all the cattle and sheep off the island as soon as it took possession.
Instead of native grasses beginning to flourish, weedy, bamboo-like fennel grew in abundance, choking out native plants, Shaver said.
Feral pigs still roam much of the rest of the island. The National Park Service is negotiating to buy the final 25% of the 10% of the island that is still privately owned. If the Park Service is successful, it will remove the sheep kept there by the Gherini family.
Shaver said that when money allows, the Park Service will also remove the feral pigs from all of Santa Cruz Island.
On Santa Rosa Island, the problems with non-native animals will take longer to resolve, Shaver said. Three years ago, the Park Service hired professional hunters to kill the feral pigs on the island.
But under the agreement to purchase the island from Vail & Vickers in 1987, the cattle ranching and deer and elk hunting operations will be allowed to continue until 2012, as long as they don’t interfere with park management.
Shaver said he sees no such interference, but that the conservation agreement will outline measures to prevent any further decline of native species until the agreement expires.
“The land is in transition from ranch to park and eventually we will have all the non-native animals off the land,” he said. “In the meantime, we need to learn as much as we can about the ecosystems so we don’t end up with a catastrophe when we pull the animals off.”
But other interested parties, such as the California Native Plant Society, say the operations need to be curtailed now.
The society’s staff botanist, Mark Skinner, said he realizes that the Park Service would not have been able to acquire Santa Rosa at all without the agreement to operate the cattle ranch, but he said the native species could be irreparably damaged if the Park Service waits until 2012 to act.
Skinner said that the Native Plant Society brought up the urgency of the matter in a lawsuit and that the Fish and Wildlife Service is in the process of proposing that 18 plants on the Channel Islands be added to the endangered species list.
“Impacts from introduced herbivores are overwhelmingly the No. 1 threat to these plants,” he said. “The vegetation and rare plants are in really bad shape now, and some of them will undergo additional decline in the next couple of decades, and it’s possible some may disappear.”
The same may be true for another 20 species of plants and animals that are candidates for the endangered species list, biologists said.
Skinner said the National Park Service tries to abide by its mandate to be a good steward of the land, but that it also wants to honor its agreement with ranchers.
“But those two objectives are mutually exclusive,” he said. “It’s the ranching operations on Santa Rosa that are having such an adverse impact. The Park Service is not taking sufficient initiative to change the practices to protect rare and endangered plants.”
It was the California Native Plant Society that sued the Fish and Wildlife Service in 1991 for failing to propose for listing 159 species statewide that were identified as candidates.
As part of the suit settlement, the Fish and Wildlife Service agreed to propose the plants for the endangered species list by September, 1996. Skinner said the society hopes to avoid any future legal action against the federal government to force it to take care of the Channel Islands.
But the islands are far to valuable to ignore, he said.
“The Channel Islands are a very special place,” he said. “The Channel Islands have a number of endemic species found no place else in California or in the world. From a biological standpoint, they’re priceless.”