Tilapia farming practices in some countries have also raised concerns for consumers. The best sources of farmed tilapia include the United States, the Netherlands, Canada, Peru, and Ecuador. Wild-caught tilapia are also available, but wild versions are hard to find, so most are farmed fish. Fortunately, finding good-quality farmed tilapia fillets is generally not a problem. You can easily find tilapia fillets in many supermarkets. While they are sold most commonly as frozen fillets, you can find fresh fillets as well. All in all, tilapia that is raised properly is a low-mercury fish that's a great source of nutrition.