Answer:
59 feet below sea level
Explanation:
(It might be a little confusing because the question says "swim up" which might think you need to add when you actually need to subtract).
Keep in mind that sea level is exactly 0 feet.
73-14 = 59
The fish starts off at 73 feet below sea level.
It swims up 14 ft.
I took 73 and subtracted 14 from it and got 59.
Does this make sense? I'm here if you need help clarifying!
Hope this helps!