This contrail, a brick red streak of processed krill, more watery than particulate, was our first direct evidence that blue whales were feeding in winter at the Costa Rica Dome.

• 这条轨迹是消化过的磷虾残渣，较稀而不结块，这是我们头一次得到直接证据，确知蓝鲸冬天在哥斯达黎加圆突区进食。