College of Marine Science, University of South Florida, St. Petersburg, FL, USA.
Biota.earth, Berkeley, CA, USA.
Sci Rep. 2020 Apr 29;10(1):7282. doi: 10.1038/s41598-020-63875-y.
Predators impact preyscapes (3-D distribution of forage species) by consuming prey according to their abilities or by altering prey behavior as they avoid being consumed. We elucidate prey (Antarctic silverfish[Pleuragramma antarctica] and crystal krill[Euphausia chrystallorophias]) responses to predation associated with the marginal ice zone (MIZ) of the McMurdo Sound, Antarctica, polynya. Prey abundance and habitat was sampled across a 30 × 15 km area by remotely-operated vehicle, and included locations that were accessible (ice edge) or inaccessible (solid fast ice) to air-breathing predators. Prey and habitat sampling coincided with bio-logging of Adélie penguins and observations of other air-breathing predators (penguins, seals, and whales), all of which were competing for the same prey. Adélie penguins dived deeper, and more frequently, near the ice edge. Lowered abundance of krill at the ice edge indicated they were depleted or were responding to increased predation and/or higher light levels along the ice edge. Penguin diet shifted increasingly to silverfish from krill during sampling, and was correlated with the arrival of krill-eating whales. Behaviorally-mediated, high trophic transfer characterizes the McMurdo Sound MIZ, and likely other MIZs, warranting more specific consideration in food web models and conservation efforts.
掠食者通过捕食猎物，或者通过改变猎物的行为来避免被捕食，从而影响猎物的生境（饲料物种的三维分布）。我们阐明了南极银鱼（Pleuragramma antarctica）和水晶磷虾（Euphausia chrystallorophias）对与南极洲麦克默多海峡边缘冰区（MIZ）相关的捕食的反应。通过遥控潜水器对 30×15 公里的区域进行了猎物丰度和栖息地的采样，包括可到达（冰缘）或不可到达（坚固的快速冰）空气呼吸掠食者的位置。猎物和栖息地的采样与阿德利企鹅的生物记录和其他空气呼吸掠食者（企鹅、海豹和鲸鱼）的观察同时进行，所有这些掠食者都在争夺相同的猎物。阿德利企鹅在冰缘附近潜水更深、更频繁。冰缘处磷虾数量减少表明它们已经耗尽，或者对沿冰缘增加的捕食和/或更高的光照水平做出了反应。在采样过程中，企鹅的饮食逐渐从磷虾转向银鱼，这与磷虾食性鲸鱼的到来有关。麦克默多海峡 MIZ 以行为介导的高营养转移为特征，可能还有其他 MIZ，这在食物网模型和保护工作中值得更具体的考虑。
