Translation of "헤엄치며" in English

‎상어는 주변을 헤엄치며 ‎문어 냄새를 추적했어요 ‎그 모습을 보니 불안감이 엄습했죠

Then you just saw the shark swimming on the periphery, picking up her scent. And I thought, "Oh, no, this is this whole...