Welcome to BYC. Glad you decided to join our flock. If your chicks can slip through the openings in the chain link, there are plenty of predators that can slip though them as well such as rats, snakes, weasels, minks, etc. Also predators such as raccoons will reach through the openings in the chain link and grab your chickens with their paws, pulling them against the fence and killing them. I would strongly advise putting hardware cloth over that chain link. Also you need to make sure that the top of the enclosure is covered with hardware cloth as well or predators will climb up the chain link and enter from above. Adding hardware cloth will add some expense to your coop/run, but it's a one time expense and it's cheaper than replacing your flock. Also, make sure that you use either a padlock or a double action latch on your coop door as raccoons can easily figure out how to open a single action latch. There is a good article at
http://www.the-chicken-chick.com/2013/07/11-tips-for-predator-proofing-chickens.html on predator proofing your chickens. Please feel free to ask any questions you may have. We are here to help in any way we can. Good luck in protecting your flock from predators.