This review article examines the effect of aquaculture on global fish supplies. It finds that while aquaculture has more than doubled global fish production in the past 15 years and now accounts for over 25% of fish for human consumption, some aquaculture practices may diminish wild fish stocks. Specifically, farming carnivorous species like salmon and shrimp requires large inputs of wild fish used for feed. On balance, aquaculture still contributes to global fish supplies, but to sustain this contribution into the future, the industry must reduce reliance on wild fish in feeds and adopt more environmentally sound practices.