winter storms. The forests may also serve 

 as protection from predators such as white 

 sharks. If kelp surface canopies are 

 present, otters sleep in them, and are 

 often observed with strands of kelp draped 

 over their bodies, presumably to prevent 

 movement (Kenyon 1969). Jameson's (pers. 

 comm. ) current studies on sea otter 

 behavior have also shown a close 

 association between sea otters and kelp. 

 Otters are most commonly found in 

 protected inshore kelp canopies in central 

 California in winter, when storms remove 

 canopies in deeper water. Otters 

 gradually move out into the offshore 

 canopies as these reform in spring and 

 summer. After the extreme winter storms 

 of 1982-83, Jameson (pers. comm.) observed 

 that most otters along the shore near San 

 Luis Obispo were inhabiting the few small, 

 shallow stands of giant kelp that 

 remained; we observed similar behavior in 

 Carmel Bay. 



Kelp forests also function as a 

 nursery area for females with pups. 

 Sandegren et al. (1973) postulated that 

 females give birth to pups while in the 

 water. Jameson (1983) discovered a 

 mother-pup pair hauled-out on land minutes 

 after the pup had apparently been born. 

 He hypothesized that sea otters give birth 

 in kelp forests whenever possible. When 

 kelp surface canopies are unavailable, 

 however, birth may be accomplished on 

 land. In heavy seas, pups use kelp 

 strands as anchors while females forage. 

 During winter storms in central California 

 when the kelp canopy is reduced, increased 

 competition between mother-pup pairs may 

 occur for space in the available canopy 

 (Sandegren et al . 1973) . 



The diet of sea otters in kelp 

 forests consists of epibenthic 

 invertebrates commonly associated with low 

 intertidal and subtidal rocky substrata 

 with deep crevices (e.g., sea urchins, 

 abalone), and with kelp fronds (e.g., 

 Tegula spp., kelp crabs; see review in 

 Woodhouse et al. 1977, Estes et al . 1981). 

 Otters forage at depths to 40 m, securing 

 their prey with their forepaws, and 

 returning to the surface to eat (Kenyon 

 1969). California sea otters display a 

 unique type of tool-using behavior when 

 feeding on hard-shelled invertebrates: 

 food items may be pounded against a rock 



held on the otter's chest while floating 

 at the water's surface (Fisher 1939). 

 Houk and Geibel (1974) described an 

 incident of a sea otter, underwater, 

 pounding an attached abalone with a rock. 



Costa (1978) calculated that an 

 average-sized otter must consume 25% of 

 its body weight daily to meet its energy 

 needs. Ostfeld (1982) studied the 

 foraging "strategies" of a colonizing 

 group of otters in a Macrocystis forest 

 off Point Santa Cruz, California. 

 Initially, red sea urchins were the 

 otter's major prey item. Kelp crabs and 

 clams replaced urchins as major prey items 

 as urchins became increasingly scarce. 

 Abalone and cancer crabs were consistently 

 exploited as dietary items at relatively 

 low levels. Other rocky substrata prey 

 items include snails, mussels, octopus, 

 chitons, tubeworms, limpets, barnacles, 

 scallops, and starfish (Ebert 1968, Wild 

 and Ames 1974, Shimek 1977, Woodhouse et 

 al. 1977, Estes et al. 1981). Van Wagenen 

 et al. (1981) observed sea otters preying 

 on seabirds. 



Otters are able to adapt to diverse 

 environments (Woodhouse et al. 1977). The 

 spreading fronts of the California 

 population have successfully occupied 

 sandy and silty bottom coastal zones, 

 exploiting Pismo clams, gaper clams, razor 

 clams, mole crabs, and even echiuroid 

 "worms" as prey (Wild and Ames 1974, 

 Stephenson 1977, Hines and Loughlin 1980). 

 Outside the protection of the kelp canopy, 

 the sea otter is susceptible to attacks by 

 the great white shark (Ames and Morejohn 

 1980). Other than man and parasites, this 

 shark is its only known predator in 

 California waters. 



Before commercial exploitation, the 

 range of the sea otter extended in a 

 continuous arc from the northern islands 

 of Japan, along the Kamchatka coastline, 

 across the Aleutian Islands chain, and 

 southward along the west coast of North 

 America into lower Baja California, Mexico 

 (Kenyon 1969). The population southeast 

 of the Aleutian chain was believed to be 

 extinct until the discovery in 1938 of a 

 raft of 50 to 90 individuals along the 

 central California coast (Bolin 1938, 

 Woodhouse et al. 1977). After legal 

 protection was afforded, the range of the 



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