It looks like some kind of underwater ballet: two killer whales rubbing their bodies together as they move through the water. What's trickier to see in this new research footage, that was captured by scientists using drones, is a piece of kelp between the bodies of the two animals.这种看上去就像某种水下芭蕾舞的动作其实是两只虎鲸在水中移动时一起摩擦着身体。在科学家用无人机拍摄的这段研究画面中，更难以观察到的是这两只动物的身体之间有一条海带。

The scientists don't know if this seaweed tool use is unique to the population of orcas they've studied, a group known as the Southern Resident Killer Whales, but they think it could have multiple benefits for the animals.科学家尚不清楚这种使用海藻作为工具的行为是否是他们所研究的、被称为南方居留虎鲸这个种群所特有的行为，但他们认为这一行为可能对虎鲸有多种益处。

In 12 days of following these killer whales the researchers saw kelp rubbing 30 times. They hope that this new intimate insight into the lives of these magnificent but threatened animals will help highlight the importance of protecting the coastal waters where they live, hunt and often massage one another.在追踪这些虎鲸的 12 天当中，研究人员观察到了 30 次用海带按摩的行为。研究人员希望，本次对虎鲸这种宏伟而受威胁的生物生活方式的近距离观察了解能帮助他们强调保护海岸水域的重要性，这些水域是虎鲸赖以生存、捕猎和时常按摩彼此的栖息地。