Answer:
Sunlight
Explanation:
An abiotic factor (non living) such as sunlight could limit populations as at deeper depths, there is a lack of sunlight because rays have difficulty penetrating through deep depths of water. This means that certain plants which require sunlight for photosynthesis may not be able to grow.
Of course, there are other abiotic factors such as temperature, water salinity, nutrient levels etc.
hope this helps :))
