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Sanctuary Rocky
Intertidal Open
Ocean & Endangered
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Examples of Endangered and Threatened Species in the Sanctuary Before an animal species can receive protection under the Endangered Species Act, it must first be placed on the federal list of endangered and threatened wildlife. An "endangered" species is one that is in danger of extinction throughout all or a significant portion of its range. A "threatened" species is one that is likely to become endangered in the foreseeable future. More than 55 percent of all the species federally listed as threatened or endangered reside in California. Twenty-six of these reside within the Sanctuary. One Sanctuary resident, the American Peregrine Falcon, brings a hopeful sign for the future. It was removed as a threatened species in August 1999 due to the species' recovery but will be monitored closely for the next five years. The tidewater goby is currently under consideration for delisting in the future.
We are very close to losing coho salmon from coastal streams of the Monterey Bay National Marine Sanctuary. The only remaining streams in the Monterey Bay region having adult coho salmon runs in most years are Scott and Waddell creeks, located in northern Santa Cruz County. They have been lost from the larger San Lorenzo River and Soquel Creek watersheds, and a recovery plan is underway. Steelhead populations are faring better than coho around the Sanctuary. Since the drought of 1987-92, higher annual rainfall has allowed increased juvenile populations in most watersheds with some population stability. Most of the major coho and steelhead watersheds entering the Sanctuary are described briefly below. In Scott and Waddell creeks, coho populations have been severely reduced by natural phenomena such as drought and late winter storms as well as water diversions, erosion induced by logging, and a toxic chemical spill on Waddell Creek. The mouth of Scott Creek is negatively impacted by the Highway 1 bridge, which often delays the opening of the sandbar to allow upstream migration and causes premature sandbar closure in the spring. Adult coho populations are unstable at 100 to 200 in Waddell and 100 to 500 in Scott Creek. Steelhead, with their more flexible life history for spawning and rearing, are faring better at stable adult populations of 200 to 400 in each creek. The San Lorenzo River watershed is impacted by the flood control channel through Santa Cruz; the artificial breaching of the summer sandbar at the river mouth, which destroys lagoon nursery habitat; water diversion, which makes spawning migration difficult, if not impossible; and accelerated logging without adequate regulation and enforcement. The San Lorenzo River supports approximately 2,500 steelhead adults and 150,000 juveniles. The Soquel Creek watershed is threatened by suburban sprawl in the lower valley, with proposed winter water diversion and increasing amounts of impermeable surfaces that increase winter storm flows, washing away steelhead nests and reducing summer base flow important for rearing juveniles. Increased logging without adequate environmental protection has accelerated erosion and sedimentation. The lower five miles of Soquel Creek have lost substantial riparian vegetation to stream bank erosion, and few steelhead use this reach for rearing, presumably due to high summer water temperatures and poor spawning success. Soquel Creek supports 500 to 800 adult and 50,000 juvenile steelhead. The large Pajaro River watershed is being devastated by human development outside Santa Cruz County. Municipal water diversion, reservoirs, and agricultural pumping have drastically reduced rearing habitat throughout. Steelhead habitat exists only in the upper headwaters of tributaries. Thus, successful adult passage to spawning grounds and successful smolt passage to Monterey Bay are critically important. The lower reaches of most Pajaro tributaries go dry in summer. If they become dewatered earlier in spring, smolt migration will become even more tenuous. During the past drought, only hatchery augmentation maintained the Pajaro steelhead population, which probably numbers in the low to mid hundreds as adults. Though the steelhead run of the Carmel River has rebounded from near extinction since the drought to 500+ adults counted at the San Clemente Dam in the late 1990s, the population is maintained by an active rescue effort. This involves relocating juveniles from the lower river to perennial habitat below San Clemente Dam each summer/fall, as municipal well pumping dewaters the lower valley. Adults must be trapped and trucked above Los Padres Reservoir in winter to access 15+ miles of the best habitat. Spawning and rearing habitat in the lower watershed has become severely degraded from sedimentation caused by increased agricultural development (vineyards) and is further threatened by sediment to be released from behind San Clemente Dam. In the Santa Rosa Creek watershed, juvenile steelhead in the lower valley are restricted to shallow pools -- primarily under woody debris and overhanging willows -- and in the upper canyon, to deeper pools, hiding under banks protected by riparian trees and under large boulders. Potentially increased water dev-elopment that would further reduce summer base flow is a concern here. Recent agricultural conversion from cattle grazing to vineyards may result in increased stream sedimentation with reduced summer base flow. The juvenile population has increased steadily since the drought, to about 50,000, with a probable adult run of 200 to 400 fish in this important southern watershed. Although juvenile steelhead numbers have improved, coho have
been lost from major watersheds and risk extinction within the
Sanctuary. Coho and steelhead habitat is threatened throughout
the Sanctuary from increased water development, urbanization,
flood control projects, marine mammal predation, agricultural
conversion, and destructive logging practices. The California
Forest Practices Rules must be strengthened, and long-term monitoring
and maintenance of erosion control measures should be instituted
after timber harvest to allow further coho and steelhead recovery.
No-cut buffers should be established and enforced along all watercourses
in all timber harvest zones, residential areas, and agricultural
lands to protect remaining habitat. Donald Alley
One of the greatest mysteries of the sea turtle world is where the pelagic leatherback (Dermochelys coriacea) spends its time. The leatherback is the largest turtle in the world and has the widest geographic range of any reptile. It is found in all of the world's major oceans and has been observed from the Arctic Circle to the edges of the Antarctic convergence zone. Leatherbacks are also one of the deepest diving animals known -- descending to depths in excess of 1,300 meters. We have monitored individuals as they circumnavigate entire ocean basins -- distances of more than 10,000 kilometers -- in a single year. To observe or study leatherbacks is extremely difficult, however: not only do they range across open oceans, they rarely stop swimming and they spend more than 80 percent of their lives underwater. For these reasons, their activities in the open sea remain poorly understood. Yet understanding the oceanic movements of this turtle, and applying
this knowledge to related management issues, is critical to its
survival. The leatherback is the world's most endangered sea turtle,
with populations in the Pacific Ocean declining at a disastrous
rate. Since 1980 leatherback populations in the Eastern Pacific
have dropped by more than Satellite telemetry has become a vital tool in our efforts to understand this species' use of the oceans. In our studies, we have monitored the movements of female leatherbacks from nesting beaches in the Atlantic and the Pacific and discovered that these turtles make extraordinary post-nesting migrations of tens of thousands of kilometers, sometimes along distinct oceanic corridors. However, getting access to the turtles in order to attach transmitters is challenging. In all past studies transmitters were attached to females during nesting (when the turtles were on land and therefore accessible). Further, due to technical challenges most tracking cycles have been limited to less than a year in duration, with our longest track covering eighteen months -- whereas in the Pacific leatherback females only return to nest every three years. Where do they travel in the intervening years and what habitats are important to this global wanderer? These are questions that we have yet to answer.
This summer, with the financial support of our home institutions (National Marine Fisheries Service and Hubbs Sea World Research Institute) and Chevron Oil Company and with the logistical support of Moss Landing Marine Laboratory and the Monterey Bay National Marine Sanctuary, we accomplished an exciting breakthrough. For the first time in the Pacific, transmitters were placed on leatherbacks at sea. We captured, tagged, and released two mature females while they were foraging on jellyfish in the Sanctuary. Genetic analysis has revealed that both turtles originate from Western Pacific nesting beaches, possibly in Indonesia. As this is written, both turtles appear to be headed directly to their natal areas in Asia on what we hope is a pre-nesting migration. Each transmitter is sending us data that are important to understanding habitat use, including water temperature, the depth and duration of dives, and the length of time spent at particular depths. If we are successful at tracking these turtles all the way home, it will represent the first time leatherbacks have been tracked during their migrations prior to nesting, as they move from foraging grounds in the eastern Pacific to their nesting beaches in Asia. (To follow these leatherbacks with us, visit our Web site at: www.hswri.org.)
Scott A. Eckert1 and Peter H. Dutton2 |
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For comments or question please refer to the Webmaster Last modified on: Jan 15, 2000 |
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