Why Tilapia? Species Selection at the Aquaponics Project

IMG_0853Tilapia is one of the most commonly raised fish species in aquaponics systems, but it is not universally desirable among consumers. Why is it that tilapia is such a common choice, and why are we raising them at the CLF Aquaponics Project?

  1. Tilapia are hardy. Really hardy. In the aquaculture industry they have a reputation for being very difficult to kill, especially compared to more finicky species such as trout. They can survive wider ranges in pH, temperature, and ammonia than many other fish species, and they quickly adapt to varying conditions. Read More >

When the Fish and Plants Don’t Get Along

2013-aquaponics-tankIt’s easy to get excited about aquaponics. On the surface it seems simple: the waste from the fish is recycled into valuable nutrients for the plants, while the vegetables purify the water for the fish. Aquaponics, like any form of agriculture, is dynamic, changing with the seasons and over time. As the fish and plants grow, their needs change and shift the balance. Read More >

U.S. Testing of Seafood Imports Falls Short

A Center for a Livable Future study, published recently in Environmental Science and Technology, shows that testing of imported seafood by the U.S. Food and Drug Administration (FDA) is inadequate for confirming its safety or identifying risks.

About 85 percent of seafood consumed in the U.S. is imported, and most of those imports are produced in overseas fish farms, where drugs may be administered to the fish to treat and prevent fish diseases. In terms of food safety, imported seafood is one of the most significant high-risk foods, and FDA oversees the safety of imports. CLF researchers David Love, PhD, and colleagues believed it was important to measure and evaluate the degree to which imported seafood is tested for drug residues. Read More >

Recirculating Farms Coalition: Fish Farms Meet Agroecology

Sahib Punjabi's recirculating farm in Winter Park, Fla.

The United States needs better food systems, and it needs more jobs. Aquaponics, a relatively new type of urban food production model, can give us both—sustainable food and green jobs.

Currently, the U.S. imports about 85 percent of our seafood, a large fraction of which is produced in overseas fish farms, by a process called aquaculture. Another 10 percent is “domestic wild catch,” which is made up of seafood caught by U.S. fishermen (NOAA). The remaining 5 percent comes from U.S. aquaculture.  As global wild catch declines, aquaculture is steadily increasing as a viable replacement, although some aquaculture operations are criticized for being sited in open water or rivers, where fish escapes, exchange of fish diseases between farmed and wild fish, and environmental pollution are of concern.

But there is a different approach to aquaculture that addresses many of these concerns: aquaponics. Aquaponics is typically land-based, closed-system farming that is designed with the principles of agroecology in mind— fish species and vegetable crops are raised together in harmony— because fish waste serves as liquid plant fertilizer and plants strip the water of chemicals that are harmful to fish.

Agroecology, a method for integrating biological systems into agriculture, is widely recognized as a potential solution for increasing farm productivity and environmental sustainability of agriculture. Olivier De Schutter, UN Special Rapporteur on the Right to Food, is strongly in favor of the agroecology approach, in which farmers create “complex farming systems that replicate the complexities of nature.” Read More >

Reading between the lines: FDA indicates consumer preference not a reason for salmon labeling

FDA hosted a hearing on Tuesday, September 21 to discuss the hypothetical labeling of genetically engineered (GE) salmon. Just fifteen hours earlier the FDA finished hearing the debate on GE salmon approval, which gave the impression that FDA was moving faster on the issue than it actually is.  This compressed schedule caused frustration among experts, leading George Kimbrell of the Center for Food Safety to say “it is inappropriate to hold hearings on labeling before [GE salmon] are approved.”

In oral statements made before the FDA panel, Food and Water Watch (FWW) speaker Patty Lovera and the Alexis Baden-Mayer of Organic Consumers Association were not in favor of GE salmon, although if approved, Lovera recommended mandatory labeling of GE salmon. When pushed by the FDA panel on the material reasons for labeling, pro-labeling advocates often cited a lack of data on allergenicity of GE salmon or consumer preference. In a major break with other consumer advocacy groups, Gregory Jaffe from the Center for Science in the Public Interest indicated a preference for no GE labeling.

Salmon fillets in the grocery store (source: http://www.ctbites.com/home/2009/10/14/the-fresh-market-opens-in-westport.html)

Salmon fillets in the grocery store (source: http://www.ctbites.com/home/2009/10/14/the-fresh-market-opens-in-westport.html)

If GE salmon is approved, the FDA has indicated that labeling will be based only on material differences in GE salmon compared to non-GE salmon, and not based on consumer preferences for GE labeling. These views may not be consistent with surveys that show 70% of American consumers want GE food to be labeled, from data reported by Jaffe.

Industry groups, including Richard Carnevale of Animal Health Institute, stood in line to argue that there were no material reasons why GE salmon should be labeled. The CEO of AquaBounty, Richard Clothier gave a series of other arguments against mandatory labeling, including the “slippery slope” that may lead to labeling of all GE foods and if labeling “complicated the process it would be a pity.” It appears that all stakeholders, including the FDA, realize this is a complicated process, and are willing to work through the difficult decisions.

If GE salmon is approved, consumers will have the ultimate say in its success. Salmon is the 3rd most consumed seafood product in the US and its popularity and high market price will likely continue,whether or not consumers know what kind of salmon they are eating.  It remains to be seen if the aquaculture industry realizes that the rising interest in communicating where and how our food is raised may be a benefit as opposed to a liability.    Elliot Entis, the founder of AquaBounty, indicated he would be in favor of voluntary labeling as a type of product branding. Entis was in favor of calling their salmon “Panama Reds,” although one can only wonder if this is just a red herring.

– Dave Love

Maryland public hearing on proposed oyster policy draws a crowd

Citizens descended on the small town of Wye Mill, Maryland at Chesapeake College Thursday, August 5th to attend the final public comment period for Maryland’s sweeping new oyster policies. The overcast and muggy weather provided a sober backdrop for intense discussions on how Maryland will manage the future of the Eastern oyster (Crassostrea virginica)— a bivalve mollusk central to the culture and livelihood of generations of watermen.

Maryland Department of Natural Resources (DNR) staff reviewed a package of eight regulations, ranging from expanded oyster sanctuaries, changes to public shellfish fishery areas, leasing for shellfish aquaculture, to a study of power dredging. According to the Southern Maryland Online, more than a thousand people have already commented on these proposed oyster policies, which were posted on February 2010.

Tom O’Connell, Director of DNR Fisheries Service defended the plan saying “there is broad stakeholder agreement that the status quo is not acceptable” and that the policies as presented will “make it better for the oyster, the oystermen, and aquaculture.”

Eastern oyster (Crassostrea virginica)

Eastern oyster (Crassostrea virginica). Image by Tony Weeg/Creative Commons

One of the main points of contention was over expanded oyster sanctuaries. Conservation groups see these sanctuaries, instead of lost resources, as preserves where oyster populations can grown and evolve natural resistance to menacing oyster diseases. An appropriate analogy is the creation of “national parks” or sanctuaries for oysters where they can flourish, in addition to “national forests” or public waters where oysters can be selectively, commercially harvested. Signs of natural disease resistance have been reported in Chesapeake Bay oysters, which highlights need for increasing oyster sanctuaries.

There is a growing sense of urgency to approve the state’s plan. Stephanie Westby, a fisheries scientist with the Chesapeake Bay Foundation called for “ new management strategies while we still have something to protect.” A member of the Queen Anne’s Conservation Association echoed support for the new DNR plan and pointed out that rockfish and blue crabs have both rebounded from overharvesting following management the state, and oysters are next on the list of species that need saving.

Questions about the plan to increase oyster sanctuaries from 9% to 25% of remaining oyster beds and carve out private lease areas drew sharp criticism from one oystermen who asked, “why take my bottom from me?”

Marylanders have historically regarded oyster bottom— sea floor capable for growing oysters— as public property, while most other states on the East Coast, including Virginia, consider oyster bottom as privatized, leasable land. Transitioning from public oyster grounds to leasable plots in selected areas is a first step in developing oyster aquaculture in Maryland.

More than 90% of oysters consumed in the US are raised by aquaculture, so Maryland’s latest decision to promote aquaculture along with wild harvesting is consistent with, if not somewhat lagging national trends. Read More >

Book Review: The World is Blue: How Our Fate and the Ocean’s Are One


By my estimation, seventy-five-year-old author Dr. Sylvia Earle has spent more than 1% of her life underwater. If her dives were connected in time, it would be as if she slipped into the ocean on New Year’s Day and did not re-emerge until some time after Labor Day.

Her book chronicles her experiences as a 1960s pioneer in underwater exploration, with stirring accounts of the inquisitive fish and mammals she met in the deep blue. Anthropomorphizing these animals would be an insult, given all the trouble humans have caused by overfishing, pollution, and acidification of the oceans. With these issues, she deftly takes an animal’s perspective in deconstructing our troubled oceans.

I once found an enterprising hermit crab with its vulnerable posterior neatly tucked into a discarded Bayer aspirin bottle, a modern, lightweight, durable substitute for a traditional snail shell. A decorator crab on a nearby reef had artfully placed a disposable fast-food ketchup envelope on its back along with bits of algae, hydroids and normal camouflaging elements. The ketchup container actually helped the crab blend in with other trash.

Over half of all humans live near the coast where impacts are felt from habitat destruction to overfishing. One report in the journal Nature found industrial fishing has removed 90% of all large fish from the ocean. As oceanic currents sweep away human litter, a convergence of garbage is amassing in the middle of the Pacific Ocean. To make a small dent in the trash issue, Earle tells of the Ocean Conservancy’s yearly coastal clean-up that in 2008 drew participants from 100 countries, collecting 6.8 million tons of trash with the top 10 offenders being: 1) cigarette butts; 2) plastic bags; 3) food containers; 4) caps and lids; 5) plastic bottles; 6) paper bags; 7) straws and stirrers;  8) cups, plates, eating utensils; 9) glass bottles; and 10) beverage cans. So many of these items are food related, which is a sign to me that our food system is in disrepair. Read More >

International aquaculture course stresses natural systems thinking for fish farming

Last week I had the pleasure of attending the 12th annual International Aquaponics and Tilapia Aquaculture Course in St. Croix at the University of the Virgin Islands (UVI). I was able to meet and learn from many wonderful people who traveled from about 21 U.S. states and 18 countries including Canada, Mexico, six Caribbean islands, Peru, Argentina, the United Kingdom, Nigeria, Singapore, and Saipan, a tiny island in the middle of the Pacific Ocean. Course participants ranged from commercial and aspiring farmers to backyard hobbyists, non-profit and international development workers, aquaculture extension specialists, academics, entrepreneurs, and investors.


Charlie Schultz, course instructor, harvesting basil

Throughout the week, the course instructors emphasized that integratedfarming systems, such as aquaponics, can be more environmentally sustainable, resilient and potentially more profitable than monoculture of either fish or plant species. Course lectures included tilapia biology, broodstock spawning, fry cultivation and growout, plant propagation and hydroponics, integrated pest management, system design, and commercial considerations. Field work followed in-class lectures for hands-on learning activities.

Aquaponics is essentially a method for boosting profits from aquaculture (i.e., fish farming) by capturing excess nutrients inherent in fish waste to raise plants as a secondary revenue crop. In this regard aquaponics borrows heavily from hydroponics — a method for raising plants in a soil-less, nutrient-rich water, but it differs in one key respect. Hydroponics is performed with microbiologically clean water where all inputs come from fertilizers, while in aquaponics “we keep our system dirty” says the course’s lead instructor and UVI professor, Dr. Jim Rakocy, repeating the mantra this leader in the aquaponics movement has developed during his 30 years of research. Read More >

Aquaculture Bill to Protect Ocean Ecosystem

A new aquaculture bill entitled the “Research and Aquaculture Opportunity and Responsibility Act” introduced last week by Senator by David Vitter (Louisiana) is worthy of support. As described in the press release, the bill calls for a 3.5 year delay on new offshore aquaculture permitting. The bill would require a report to Congress on the environmental risks, economic impacts and regulatory guidelines for offshore aquaculture.

fish farm, Scotland creative commons

fish farm in Scotland; creative commons

The US lags behind other countries, like Norway, Chile and the UK, in marine aquaculture production, and this bill would further delay activity. Understanding the risks of offshore aquaculture has long-term benefits that may be difficult to quantify, at least compared to the more immediate profits from fish sales. It is important, however, to conduct such research to ensure the health of our waters and sustainability of our fisheries.

The Vitter bill is supported by environmental and consumer advocacy group, as mentioned in the press statement, and does not shy away from confronting potential human health and environmental impacts of offshore aquaculture. The bill asks regulators to devise guidelines to prevent:

  • “pollution from concentrated fish feces and uneaten food;
  • parasites, diseases, and their effects on native wildlife species;
  • escape of marine species from offshore aquaculture facilities;
  • degradation of wild stocks of marine species;
  • negative impacts on commercial and recreational fishing;
  • inefficient reliance on wild forage fish to feed marine species in offshore aquaculture facilities;
  • inappropriate use of chemicals to treat parasites and disease in off- shore aquaculture;
  • negative health impacts from consumption of marine species produced in offshore aquaculture.”

The economic potential of land-based recirculating aquaculture also will be studied if the bill is made law. Recirculating aquaculture is a more biosecure form of fish farming where the water and fish waste are treated, then recycled back into the fish tanks. Recent 2010 funding initiatives by NOAA Aquaculture Program targeted just marine aquaculture, and therefore Vitter’s bill may help support aquaculture for land-locked states and states that do not have access fishable waters, it could also be an important step in promoting a more sustainable form of fish production.

– Dave Love

Fish and Health: More to the Story

I’d like to expand a little on my recent interview for a CNN piece by Elizabeth Landau entitled “Farmed or wild fish: Which is healthier?

At face value, this question can partialy be answered by comparing the nutritional content in farmed and wild fish and weighing the health benefits of fish consumption against the risks of pollutants present in fish. The Institute of Medicine of the National Academies has expertly covered this topic in Seafood Choices: Balancing Benefits and Risks, and authorities like Dr. Charles Santerre, have produced an excellent seafood consumer guide (Fish for Your Health wallet card) based on Omega-3 fatty acids, mercury and PCBs in fish. These comprehensive benefit-risk analyses and consumer-friendly information are useful and important contributions, though focus solely on human health.


In any discussion of seafood, it is also important to consider the negative impacts of fish farming or wild-caught fishing can have on the environment. These environmental impacts are considered as the basis for progressive fish certification schemes (examples: Friends of the Sea or Marine Stewardship Council) and consumer recommendation lists (example: Monterey Bay Aquarium wallet card) (read more). Sustainability should be an important consumer consideration, though in these certification schemes and consumer guidance materials, human health considerations are often absent.

Read More >