Which environmental factor could lead to a decrease in genetic variation in a population of tuna? an increase in food availability
an increase in pollution
a decrease in tuna fishing
a decrease in tuna predators

The environmental factor that could lead to a decrease in genetic variation in a tuna population is an increase in pollution (second option).

Explanation:

There is a correlation between genetic variability and environmental pollution, the latter being a factor that impacts negatively on the variability of a specific population.

The concept of pollution stress not only implies a low rate of reproduction, but it is also a factor that prevents genetic exchange with other populations, which is a factor that makes the genetic variability decrease in a population.

For these reasons an increase in pollution implies a decrease in genetic variability in a tuna population.

only about ten percent of the energy at one trophic level is passed on to organisms at the next trophic level. the remainder of the energy is used in life processes or lost as heat.