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appendix b final 2008 biological surveys of los angeles and long ...

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10.0 Marine Mammals<br />

Gray whales differ from other baleen whales,<br />

primarily in their feeding behavior. These<br />

whales are bottom feeders, taking up<br />

mouthfuls <strong>of</strong> sediment <strong>and</strong> then straining out<br />

water <strong>and</strong> mud through their baleen to capture<br />

benthic invertebrates.<br />

In San Pedro Channel areas toothed whales<br />

<strong>and</strong> particularly dolphins can be found in larger<br />

groups <strong>of</strong> up to a thous<strong>and</strong> or more<br />

(Leatherwood <strong>and</strong> Reeves 1983). Several<br />

species <strong>of</strong> dolphin <strong>and</strong> porpoise that are<br />

commonly found in coastal areas near Los<br />

Angeles include the Pacific white-sided<br />

dolphin, Risso’s dolphin (Grampus grisseus),<br />

Dall’s porpoise (Phocoenoides dalli),<br />

bottlenose dolphin, northern right whale<br />

dolphin (Lissodelphis borealis), <strong>and</strong> common<br />

dolphin, with the common dolphin the most<br />

abundant (Forney et al., 1995). Bottlenose<br />

dolphin (Tursiops spp.) occur from southern<br />

California to the tropics. In California, both<br />

coastal <strong>and</strong> <strong>of</strong>fshore forms are found<br />

(Lagomarsino 1992). The coastal form inhabits<br />

shallow areas beyond the surfzone <strong>and</strong> is<br />

sometimes observed in bays <strong>and</strong> estuaries. This species is generally abundant, especially in<br />

southern California coastal waters.<br />

10.4 HISTORICAL COMPARISONS<br />

Since most marine mammals were observed or sighted during other survey activities, it is<br />

difficult to compare historical levels among previous Port baseline <strong>and</strong> monitoring studies. It is<br />

likely that the diversity <strong>and</strong> abundance <strong>of</strong> marine mammals have not changed significantly<br />

between the baseline <strong>surveys</strong>. Some <strong>of</strong> the most commonly observed species, such as<br />

California sea lions <strong>and</strong> harbor seals, can be seen on channel markers (buoys), sleeping on<br />

boat swim steps (California sea lions), <strong>and</strong> hauled out on riprap rocks that line various locations<br />

throughout the harbors.<br />

10–2 <strong>2008</strong> Biological Surveys <strong>of</strong> Los Angeles <strong>and</strong> Long Beach Harbors<br />

April 2010

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