My advice, don't buy salmon oil from Amazon. We ordered this brand all the time from Amazon. The kidlets liked it.
However starting a few shipments ago every box came covered in salmon oil. They wised up and started shipping it in a bag since it leaked so much. But even then we were left with a bag slimed full of salmon oil and the container itself covered in it. We'd have to open the bag in the sink, wash the container before being able to handle it without dropping it. I suspect it has more to do with the knocks and bumps that happen with that kind of container than with the particular pump on that brand.
Since then we've gone back to purchasing whatever brand is available from the local pet store. Better than having who knows how much covering the packaging.