Which environmental factor could lead to a decrease in genetic variation in a population of tuna

The answer of the given question would be the second option. The environmental factor that could lead to a decrease in genetic variation in a population of tune is an increase in pollution. The option that only shows an environmental factor is pollution. The effect of pollution on the population of fish is that it leads to some damaging effects that affects the life cycle of the fish. 

This is s cute awee : (( . well if she's showing you signs that she may like you , then shoot your shot ! don't be afraid . & if you're unsure that she's giving you these signs , then wait out for a little bit . most girls are different . some may act really sweet , but only bc you're a good friend of hers . that , or she might like you . you just never know . but i think you should sit down with her & tell her how you feel . but don't be awkward & shy . just be straight up & tell her how you feel . if the feelings aren't mutual , then don't cry about it . you need to respect her decision & look for others in the world . feelings can be difficult & confusing , but don't be afraid to show them . i say you play it out & if you're still unsure about it , talk to her . - rach

Sure thing, i’ll you