Aquaculture will have to be the primary source of our seafood now and into the future.
(From Scientific American/ by Halley Froehlich and Rebecca Gentry) — Seafood is an essential staple in the diets of people around the world. Global consumption of fish and shellfish has more than doubled over the last 50 years, and is expected to keep rising with global population growth. Many people assume that most seafood is something that we catch in the wild with lines, trawls and traps. In fact, aquaculture (aquatic farming) accounts for just over half of all the seafood consumed worldwide.
Today aquaculture is the fastest-growing food sector in the world. Most farmed seafood is currently produced in freshwater environments such as ponds, land-based tanks and raceways, but some producers are expanding to the open ocean.
Aquaculture dates back thousands of years, but has only recently become an essential part of our global food system. However, most of the world’s wild fisheries are already fished at their maximum sustainable yield, so aquaculture will have to be the primary source of our seafood now and into the future.
This means that we need to understand how to farm fish and shellfish sustainably. We do not have broad-scale understanding today about the ecological limits and potential of cultivating seafood in the oceans. As a first step, we recently published a study that estimated the offshore potential for aquaculture in marine waters, based on the growth performance of 180 farmed fish and shellfish species. We calculated that marine aquaculture could produce as much seafood as all of the world’s wild marine fisheries, using less than 0.015 percent of the space in the world’s oceans.
Conflicting views of ocean aquaculture
Total global wild catches have remained relatively unchanged for the past two decades. In 2015, 92 million tons of wild species were harvested worldwide – the same amount as in 1995. In contrast, seafood production from aquaculture increased from 24 million tons to 77 million tons during the same time period, and is still rising to help meet growing demand. In fact, it’s estimated that the world will need around 40 million more tons of seafood as soon as 2030.
Like all food production, aquaculture affects the environment and can be done in ways that are more or less sustainable. We want our science to help avoid destructive forms of aquaculture, such as converting mangrove forests into shrimp farms, and support more sustainable production. When it is done properly, aquaculture can be an efficient farming method with reduced impacts, compared to other types of protein such as beef, pork and even chicken.