Sunday, March 16, 2014

SENA14: Is Aquaculture Sustainable?

"We must plant the sea and herd its animals using the sea as farmers instead of hunters. That is what civilization is all about - farming replacing hunting."
Jacques Yves Cousteau

Aquaculture often gets a bad rap, despite the fact that about 50% of the seafood we consume comes from aquaculture. Some people outright dismiss farmed raised seafood, generally based on outdated information. The media doesn't help, preferring to print scare stories about the dangers of aquaculture, rather than discussing the success stories. In fact, aquaculture has been getting better for years, and is continuing to work towards greater sustainability. However, the question continues getting raised: Is Aquaculture Sustainable?

I attended a conference session at the Seafood Expo North America (SENA) with that same title, Is Aquaculture Sustainable?. Moderated by Linda Odierno, Outreach Specialist for National Aquaculture Association, the panelists included: Craig Tucker, Research Leader at Agriculture Research Service/USDA; Carole Engle, Aquaculture Economist ar University of Arkansas at Pine Bluff and Jesse Trushenski, Assistant Professor at the Center for Fisheries, Aquaculture, and Aquatic Sciences

Linda Odierno started off the session stating that the National Aquaculture Association is a trade organization covering all types of aquaculture, including finned fish, shellfish and plants. Then she delved into the potential for a significant food and water crisis in the future as our population continues to expand. This was the foundation for her premise that the U.S. needs to increase its aquaculture industry, so that we have sufficient food to feed our growing population.

Currently, China engages in the most aquaculture, about 61.4% of the global total, with the rest of Asia responsible for another 27.7%. Almost 90% of the world's aquaculture is in Asia! The Americas engage in about 4.3%, Europe in 4.2%, Africa in 2.2% and Oceana in 0.3%. Concentrating just on the U.S., we find that we import 46% of our farmed seafood and 45% of our wild seafood. The U.S. only catches about 6.5% of its wild seafood and farms only 2.5% on its own.

At this time, the U.S. is close to its maximum yield from wild seafood so additional seafood will need to come from aquaculture. As the world population increases, the U.S.may find less imported seafood available for purchase, as it may be needed at home, such as in Asia. To increase U.S. food security, we need to engage in more aquaculture and we have plenty of land and water available for such purposes. But the question then arises, is aquaculture sustainable?

Craig Tucker, Research Leader at Agriculture Research Service/USDA, was enlightening in his words, providing a nice historical summary on the issues. He began by noting that the historical arc of aquaculture, from 1970 to 2014, has progressed further in that time than has land agriculture in thousands of years. During the 1970s and 1980s, a number of countries noted the potential profits from certain types of aquaculture and weren't too concerned about ecological issues. Two of the biggest types were salmon in net pens and shrimp in Asian countries. There was rapid development, little and/or poor planning, and greed involved in much of it. This led to valid criticisms about aquaculture, criticisms that have unfairly stuck to all aquaculture throughout the years.

One of the problems with such criticisms is that a broad brush is often used when aquaculture can vary widely, dependent on the type of seafood, the region, and more. In addition, during the last ten or so years, aquaculture has improved greatly. Certain types of aquaculture will always have a greater impact than other types, but that is similar to any agriculture. Why did aquaculture change, and for the better? Governmental regulatory oversight has been one significant factor, as well as environmental, non-governmental organizations (NGOs). Aquafarmers have also adopted better practices, learning that reducing waste is not only better for the environment, but also helps the farmer's bottom line too.

Aquafarmers have also sought third party certifications, to help ensure others they are being sustainable. Craig isn't sure though that such certifications actually caused better environmental practices, but may rather just focus farmers on what practices they need to work on and improve.

Craig was very complementary about the Global Salmon Initiative (GSI) especially as salmon has long been one of the most criticized farmed fish. The companies within the GSI have all agreed to abide by some rather strict standards and practices by 2020, which has led salmon farmers to up their game significantly.    

Next, Craig analyzed and compared the impact of aquaculture in four areas: energy, land use, water use, and pollution. His comparisons provided ample evidence that aquaculture is sustainable, and better than a number of other agricultural practices, such as raising cattle. With energy use, the footprint of food production, much is used in producing and procuring feed. In that regard, cattle raised in feed lots require the greatest amount of energy, while eggs and poultry and not much lower than what is used for shrimp and salmon. If we look at global averages, cattles, swine and poultry require 83.4% of the energy, while capture fisheries only need 8.3% and aquaculture also needs 8.3%. So, you cannot claim that aquaculture uses too much energy.

With land use, the productivity of aquaculture leads to 2.04 metric tons/hectare while meat, milk, and eggs only lead to 0.23 metric tons/hectare. As you can see, aquaculture also wins in the land use issue. As for water use, Craig said, "It's a fish. It needs water." Despite the obvious needs, water use for cattle still ranks very high, and even higher than most aquaculture. As for pollution, there were previous problems but it has been steadily improving during the last ten years, and is becoming much less of a problem.

Craig concluded that aquaculture still needs to continue improving, yet he also believes it will be our eventual salvation. With the population growing, and food needs expanding, aquaculture can fill those gaps, if we take action and increase U.S. aquaculture.

Jesse Trushenski, Assistant Professor at the Center for Fisheries, Aquaculture, and Aquatic Sciences, followed up with efforts to bust the myths surrounding fish feed. She began her talk noting our future needs for food. It is estimated we will need 60% more food by 2050, as well as 60% more animal protein by 2030. As about 80% of wild fish stocks have been fully exploited or in decline, we need aquaculture to step in and provide the necessary food to meet these future needs.

She continued, adding that aquaculture provides the best feed conversion ratio, the amount of feed needed to cause a one pound weight gain in an animal. For fish, ratio can be as low as 1.5 to 1, while poultry is 2 to 1, pork is 3 to 1, and cattle is 8 to 1. In addition, seafood generally has a better dressout, meaning that more of the animal is edible. For example, 50-60% of a salmon is edible, while only about 40% of a cattle is edible.

One of the challenges of feeding fish in aquaculture is that there are so many different species of fish, with a diverse range of nutritional needs. In general,you can break down feed needs into three categories: high energy/carnivores, medium energy/carnivores and low energy/omnivores. Fish feed needs to be protein dense, such as fish meal. The problem is that prices for fish meal and fish oil have been rising, increasing the costs of fish feed. That contributes to the higher prices of seafood.

She then attacked the FIFO (fish in, fish out) myth, noting that FIFO rates generally are misused, making the wrong assumptions. It often ignores the amount of fish meal left over from feeding, which can be used for other fish. When properly calculated, the average global FIFO rate is more like 0.3, meaning you get three pounds of farmed fish for one pound of wild fish used for feed and oil.

I think the attendees of this conference would agree that the panelists presented a good case that aquaculture is both sustainable and necessary. I certainly agree.

"The sea, the great unifier, is man's only hope. Now, as never before, the old phrase has a literal meaning: we are all in the same boat."
Jacques Yves Cousteau


Anonymous said...

No real surprise an industry conference finds aquaculture sustainable. But until we understand fully what is happening to wild salmon, salmon aquaculture must remain suspect.

Anonymous said...

And it would have been useful to have a critical voice (there are many) on the panel.