Gulf Shrimp Oil-Tainted? Grow Them in the Pacific

BP’s oil spill in the Gulf of Mexico will impact the shrimp sector, but an alternative way to cultivate large, tasty and less expensive shrimp may be emerging.

BP's oil spill in the Gulf and an already-tight global shrimp market have stimulated shrimp prices. Shrimp, which ranks among the world's most valuable seafood, is a favorite among U.S. consumers. More than half the shrimp consumed worldwide is farmed, with the majority being cultivated in Asia and Latin America, a market valued at $20 billion per year.

But before ordering a shrimp cocktail, consider shrimp history. According to Dr. Stephen Levitt, author of the books Freakonomics and Superfreakonomics, between 1980 and 2005 annual shrimp consumption in the U.S. nearly tripled, from 1.4 pounds to 4.1 pounds per person.

Louisiana leads in providing wild-caught shrimp, with a market share valued at $2.9 billion per year, according to the National Oceanic and Atmospheric Administration (NOAA). However, since the oil spill, Louisiana shrimp production is down 30%, according to the Louisiana Seafood Promotion & Marketing Board.

U.S. shrimp farmers must meet stricter environmental standards than other countries, making U.S.-farmed shrimp a "Best Choice" or "Good Alternative" to U.S. consumers, while imported shrimp are listed as "Avoid," according to the classification system devised by the Monterey Bay Aquarium.

The California institution is concerned about how large areas of tropical coastal mangrove forests in Asia have been destroyed to build shrimp farms. Mangroves are an important habitat for a diverse community of fish, invertebrates and birds. Loss of habitat has had devastating impacts on local artisanal fisheries that many communities previously relied upon for food.

Environmental impacts vary widely from farm to farm and country to country. "Independent certification schemes for shrimp farms are still at a very early stage of development," according to the Monterey Bay Aquarium website.

In addition, the supply chain is complex, comprising ~400,000 farmed-shrimp producers worldwide, numerous independent processing plants, multiple distributors that import the product and thousands of large retailers and restaurant chains that buy directly from distributors.

In general, domestic wild shrimp, representing ~10% of all shrimp consumed in the U.S. (about 75% of which hail from the Gulf of Mexico), is considered significantly more sustainable than farmed shrimp. Yet some NGOs claim that wild shrimping in the U.S. poses a bycatch danger to other species such as large fish and sea turtles. Until now, 90% of shrimp consumed in the United States have been farmed imports.

Problems and solutions

On his website, Levitt notes that rising demand and fishery depletion have caused a rapid increase in shrimp farming, which now provides over half of all shrimp consumed. However, farm-raised shrimp have inferior flavor, poor texture and pale color. Moreover, farm productivity is reduced by disease, such as white spot, and production scalability is limited due to environmental contamination and habitat destruction.

There are different approaches that can be used to solve this problem.

Consider Aquapods, in which hundreds of individual triangular, recycled-polyethylene panels are covered with steel wire mesh and joined together to form a geodesic sphere. Each Aquapod has a volume of 957,000 gallons and a diameter of 64 feet. The structures are placed several kilometers from shore in waters around 200 feet deep, where they are protected from storms that would destroy floating pens. The pods also provide protection from predators that breach conventional net pens.

Another alternative may be found in the methods devised by Texas AgriLife Research. One scientist in Corpus Christi believes he has achieved a new world record in shrimp production, using an environmentally-friendly system that requires no water exchange throughout the growing cycle. The new system, called a 'super-intensive raceway system,' has taken five years to develop and could revive a U.S. shrimp-farming industry that has been decimated over the years by cheaper foreign imports.

"This grow-out system could be built near large cities to serve niche markets of consumers willing to pay premium prices for tasty, fresh, never-frozen shrimp," said Dr. Tzachi Samocha, a Regents Fellow and professor at the AgriLife Research Mariculture Laboratory in Corpus Christi. "Diners could pick shrimp out of a restaurant tank, much as they do with lobsters," he added. The new system is also a greener way to grow shrimp because its water is never released into the environment. The downside: it uses a lot of water and is expensive.

Another aquafarm option is the method devised by Aonori Aquafarms, Inc. (AAI, also known as Sinaloa Seafields), a bi-national startup whose proprietary, patented technology reproduces the natural marine habitat of shrimp. Crustaceans are fed on Aonori (Ulva clathrata), a high-protein macro-alga (the one sometimes used to roll sushi). The "[f]lavor, coloration and texture are superior to farmed shrimp, [and are] comparable to wild-caught," said Armando León, CEO of Aonori Aquafarms.

AAI is running tests and raising money for a pilot program to demonstrate its innovation. The bi-national team, led by Benjamin Moll, Ph.D., the key inventor of the technology, patented the low-cost, high-yield Aonori pond-culture method that not only delivers low production costs but also provides in-pond pollution remediation and healthier shrimp.

"With little or no dependence on marine resources, no pollution, no habitat destruction, no bycatch, and no damage to sea bottoms, this is simply a better way to provide shrimp. In addition, it produces a high value co-product," explained León. He added: "AAI's shrimp-culture method produces top-quality shrimp, sustainably grown at significantly lower cost."

This method also significantly lowers cost due to decreased feed cost (at least 45% reduction), higher growth rate (60% increase), and much lower risk of disease during production.

Bigger shrimp

AAI has expertise in algae and shrimp culture, reflected in proprietary technology in the form of patents and trade secrets. León's company has been refining the idea and managing the economic and entrepreneurial factors since 1995.

AAI has two key patents, and three more that support their business model. AAI's algae-culture technology lets them grow Ulva clathrata with high productivity and low cost. For example, they promise five times the number of tons per acre per year (dry weight) and almost 10 times less cost per dry ton as can be achieved using other methods. The algae and the ecology that AAI supports serve as the major feed source for shrimp, and provide nutritional benefits that result in faster growth and much greater disease resistance than conventional shrimp culture.

The patented method developed by AAI, which asked to keep the process private, avoids the regulatory and supply issues that trouble the wild-caught shrimp industry, such as the ban on shrimp imports from the Gulf of California due to the failure to control bycatch and the expected after-effects of the Gulf of Mexico oil spill. A further benefit of AAI's technology is that it makes shrimp culture practical on the Pacific side of Baja California, using clean oceanic waters in an area isolated from other shrimp farms.

AAI Shrimp/Ulva co-culture is environmentally benign. Like other farming methods, it avoids the problems of over-fishing, bycatch and any damage to the environment at the bottom of the pond. In addition, this new technique avoids the three main environmental problems of conventional farming methods: mangrove destruction, water pollution, and excessive demand for fish meal.

How does this method solve these problems? Conventional shrimp farms require substantial water exchange to maintain water quality, taking in clean water and flushing out microalgae and bacteria, as well as mineral nutrients such as nitrogen (as ammonia, which is toxic, and nitrate), plus phosphate. Water quality stays high for extended periods and water exchange is required mainly for salinity control. In the absence of fertilization, nutrients are depleted rapidly, within two to three days, so when water discharge occurs, it can be done when nutrient content is low. This is good practice both from an environmental and an economic viewpoint.

In AAI's experience, biochemical oxygen demand of discharged water from Ulva ponds is lower than the intake water demand, so water pollution is not a problem if ponds are managed correctly. A large fraction of the nutritional needs of the shrimp are supplied by the Ulva and the microfauna it supports. "How much depends on local and seasonal conditions and stocking density," Leon explained, "so we may use supplemental feed in some phases of production. We prefer low-cost feed intended as a supplement for microfauna, with the great majority of protein supplied by Ulva, but some conventional shrimp feed may be used. The amount of balanced feed, will be much lower than in conventional shrimp farming, hence decreased demand on fisheries for fish meal."

"AAI shrimp will be sustainably grown, in the sense that farm construction and operation will not damage the environment. In addition, if energy costs rise or fossil-fuel use is restricted, our reduced water exchange needs and high fertilizer-use efficiency will deliver a greater relative production-cost advantage compared to conventional shrimp farms. Our method does not fit current designations of 'organic' but easily qualifies as sustainable (green label) under the rules laid out, for example, by the Blue Ocean Institute."

Co-production of Aonori, usable for producing nori for sushi and other products that take advantage of its flavor and exceptional nutritional values, will result in considerable additional income and more efficient use of capital.

AAI plans to open a facility in San Quintín, Baja California, in Mexico. This region has an optimal climate for marine agriculture/aquaculture, pristine ocean water, and affordable land, and is close to U.S. markets, thus reducing transportation costs.

AAI also plans to raise money that will be used to start with a relatively small operation consisting of 36 ponds, to establish the company in the marketplace, and to train personnel. The startup has established a collaboration agreement with one of the largest independent developers of new food and beverage products in the United States to create a successful 'Prime Shrimp' brand. This retailer has the know-how to turn products into viable commercial businesses.

However, problems not only inspire solutions, but sometimes create more problems. The Southern Shrimp Alliance, which represents the American warm-water shrimp industry, is concerned about "the decision by the Environmental Protection Agency (EPA) to allow undersea use of chemical dispersants, further endangering the already beleaguered Gulf of Mexico commercial fisheries," according to a statement (PDF) posted on their web page.

The impact of BP's efforts to stop the oil slick in the Gulf could destroy the crustaceans' larvae. Nobody yet knows the impact of BP's attempted solutions and how many years it could take to recover the Gulf's commercial fishing industry.