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.
1 Do have sex once a day near the time of ovulation. 2  Daily intercourse during the days leading up to ovulation might increase the odds of conception. 3  Although your partner's sperm concentration is likely to drop slightly each time you have sex, the reduction isn't usually an issue for healthy men.