The older that such fish become, the more mercury they may have absorbed. Anything that eats these fish within the food chain also consumes the higher level of mercury that the fish have accumulated. This process explains why predatory fish such as swordfish and sharks or birds like osprey and eagles have higher
The goal, then, when it comes to having a boy is to increase the likelihood that a Y chromosome sperm reaches the egg first. Many medical researchers believe that Y chromosome sperm are faster swimmers, but that X chromosome sperm have more endurance.
The truth: A manâs age matters. As men get older, the chances of conceiving and having a healthy child decline. Male fertility starts to decline after 40 when sperm quality decreases. This means it takes longer for their partners to conceive and when they do, thereâs an increased risk of miscarriage.