加州Santa Monica海湾鳍足类的生态学

研究了加州Santa Monica海湾鳍足类的生态学.从1997-2007年乘船调查了277次,发现海狮(Zalophus californianus)是最常见的动物(89%,见到的次数为1393次),其次是港海豹(Phoca vitulina richardsi,8%,n=131)和北象海豹(Mirounga angustirostris,1%,n=15).在29%的遇见次数(观察到瓶海豚205次)中,发现海狮(偶尔也发现港海豹)与瓶鼻海豚集群(Tursiops truncatus);短喙真海豚(Delphinus delphis)与长喙真海豚(D.capensis)在53% 的遇见次数(遇见真海豚次数n=155)中,发现短喙真海豚(Delphinus delphis)与长喙真海豚(D.capensis)集群;一般在沿岸水域(离岸边距离<500 m)见到海狮和港海豹,但在整个海湾也能见到,表现出这两个物种对海底峡谷的偏爱.北象海豹仅见于近海,主要在海底峡谷附近. 经常看到海狮、港海豹和北象海豹游动(50%,n=728)、进行热调节(14%,n=205)、以及取食(3.2%,n=47),但几乎见不到有社会性活动(0.21%,n=3).

Pinniped ecology in Santa Monica Bay, California

We investigated pinniped ecology at sea in Santa Monica Bay, California. Animals were studied during 277 boat-based surveys conducted in 1997-2007 documenting that California sea lion Zalophus californianus was the most observed species (89%, n sightings=1393), followed by harbor seal (Phoca vitulina richardsi; 8%, n sightings=131), and northern elephant seal (Mirounga angustirostris; 1%, n sightings=15). Sea lions, and occasionally harbor seals, were found in aggregations with bottlenose dolphins Tursiops truncatus in 29% of the sightings (n bottlenose dolphin sightings=205), short-beaked common dolphins Delphinus delphis and long-beaked common dolphins D.capensis in 53% of the sightings (n common dolphins=155). Sea lions and harbor seals were regularly observed in coastal waters (<500 m from shore) but also in the entire bay, with both species showing a preference for submarine canyons. Northern elephant seals were only seen in offshore waters and mostly in proximity of the canyons. The three species were frequently observed traveling (50%, n=728), thermoregulating (14%, n=205), and feeding (3.2%, n=47) but rarely socializing (0.21%, n=3). This is the first long-term study on at-sea distribution, occurrence, frequency and behavior of pinnipeds in Santa Monica Bay.