The Central CA MAMU IBA occupies 13,312 hectares of pelagic open water habitat. The IBA is located in the Northern California ecoregion.

The northernmost point of this IBA is Point Pescadero State Beach and the southernmost point is just south of the city of Davenport. The middle area is marked by Ano Nuevo State Park, which runs about 25 miles along the coast.

It is owned and managed as: state-other, and has the following primary uses: other and tourism/recreation-other.

Central CA MAMU is an IBA for the following species: Marbled Murrelet. It contains an estimated 1,330 Marbled Murrelet (breeding). The following species are on the Audubon WatchList: Marbled Murrelet.

Ornithological Summary

Central CA MAMU is an IBA for the following species: Marbled Murrelet. It contains an estimated 1,330 Marbled Murrelet (breeding). These surveys were conducted between 2007 and 2009. The following species are on the Audubon WatchList: Marbled Murrelet.
Marbled Murrelets are small, dove-sized seabirds with a diverse breeding range between central California and Alaska. Marbled Murrelets are unique birds in that they nest in trees in close proximity to the ocean where they feed. Instead of nesting in large colonies like most seabirds, these birds nest in solidarity or in loose aggregations in the upper, broad branches of coniferous tress. Due to various reasons, population numbers have been declining in recent years. In 1992, Marbled Murrelets were federally listed as a threatened species (U.S. Fish and Wildlife Service 1992). The total North American population is between 263,000-841,000 individuals with a separate subspecies and population in Russia (Ralph 1995). In the summer, the murrelets feed in bays, inlets, fjords and open ocean between 5-50 meters from the coast. In California, Oregon, Washington, and British Columbia the birds remain closer to shore, mostly around 5 meters. Although Marbled Murrelets are found along the coast between the Bering Sea in Alaska to Central California, the majority of the population is found in Alaska. Outside of these areas the populations become more disjointed and scare, largely due to availability of nesting sites. The total Marbled Murrelet population is estimated to range between 263,000-841,000 individuals (Ralph 1995). In California, the population is about 6,450 (Ralph and Miller 1995).

Conservation Issues

The threats to Marbled Murrelets vary depending on each location but overall populations have been declining. The decline has been attributed to a number of factors including reduction and fragmentation of old growth forests, increased predation, pollution, and mortality from fishing nets (Burket 1995). The smaller, more southern subpopulations are more at risk (Piatt and Naslund 1995). Oil spills also pose a threat to populations. Because of foraging close to shore and small body size, Marbled Murrelets are extremely high risk. Also because of their disjunct range, a large spill could wipe out many of the smaller populations. For example, the Exxon Caldez spill killed 3.4% of the Alaskan population (Carter and Kutltz 1995). Other pollutants and toxins are present are present from oil transport and development, mining, and pulp mills (Carter and Kuletz 1995, Fry 1995, Speckman 1996). Disturbances are another threat including; disturbance at the nest sites from airplanes, aircrafts, and boats, logging at nest sights and disturbance from traffic on local highways (Kuletz 1996 and Speckman 1996; USFWS 1992). Fishing causes significant mortalities to the Marbled Murrelet population especially in gillnets. About 0.5-2% of the Alaskan population and 6.2% of the British Columbian population are killed each year. Fewer numbers are killed in Oregon and California because of the ban on gillnets (Carter 1995; Piatt and Naslund 1995). Although data is lacking, these is significant evidence that suggests the populations are drastically declining by up to 50% in the last 10-20 years (Piatt and Naslund WB).

Ownership

The Central CA MAMU IBA is owned and managed as: state-other.

Habitat

The Central CA MAMU IBA is characterized by the following habitat types: open water. The IBA is located in the Northern California ecoregion. The Big Basin Redwoods State Park is located inland, which provides the breeding habitat for the feeding Marbled Murrelets. Old growth forests also thrive in Ano Nuevo State Park.

Land Use

The Central CA MAMU IBA is used for: other and tourism/recreation-other.

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