A study published in Science Advances examines the practice of government subsidies for high seas fishing—that which is conducted outside jurisdictional waters—and finds that it is often not profitable as well as being destructive to ocean health.

According to National Geographic’s analysis of the issue, such unprofitable or “marginally profitable” fishing represents only a small portion of global fishing activity, but it is often associated with damaging practices such as deep sea trawling and labor exploitation and depletes fisheries and natural habitats.

In light of the findings and in order to address the problem, National Geographic Explorer-in-Residence and lead author on the study Enric Sala suggests development of a high seas marine reserve that covers two-thirds of the world’s oceans.

Read more in the National Geographic article or watch Sala’s TED Talk.