Nothing Fishy About the Smell of Success in California Sea Grant’s Seafood Extension Program
May 9, 2006
Contact: Christina S. Johnson, csjohnson@ucsd.edu, 858-822-5334
The issues come and go for Pamela Tom, but her message to consumers remains the same: "Seafood is good for you."
Tom manages a seafood education and outreach program for California Sea Grant's Extension Program. She oversees one of the most comprehensive sources of information about seafood safety and quality anywhere – the Seafood Network Information Center (SeafoodNIC). Her website http://seafood.ucdavis.edu is recognized worldwide in industry and government circles as the definitive one-stop source of seafood information. Last year she was lauded as "technologist of the biennium" by an international fish inspectors group for her website and for her role in creating seafood safety and quality training programs.
California Sea Grant educator Pamela Tom (right) confers with Lori Randall and Mario Pineda Vergara during an April 2006 train-the-trainer course offered in Dallas, Texas. Thirty-one participants from nine countries learned about seafood safety management procedures. Credit: Jon Bell (Louisiana State University Sea Grant Seafood Specialist)
Among the items docked at Tom's virtual port are links to more than 50 different institutes, trade associations and seafood councils throughout the country; nutrition and food labeling information for educators and retailers; an A-to-Z guide of national and international regulations affecting seafood commerce for government agencies; advice to consumers on how to spot a safe seafood seller and, of course, recipes on what to do with the catch of the day. These days one of Tom's chief concerns is misinformation that may be distorting consumers' perceptions of a source of high-quality, heart-healthy protein.
"The benefits of consuming seafood are becoming overshadowed by some of the hype I've seen that deals with the risk of consuming certain varieties of seafood," she said in a recent interview. "But studies on the benefits and risks of seafood consumption show that fear to be overblown."
Concern about contaminants such as mercury, for instance, need to be put in context so as not to tarnish the image of all seafood, according to Tom. Many ocean fish contain trace amounts of methylmercury, but the risk to people is very small. In large predator fish like shark, mercury levels become elevated, but that shouldn't scare people away from eating other types of fish. "There are plenty of fish with low or undetectable amounts of mercury," she said. "Consumers need sound, science-based information to help them select what fish to eat."
The U.S. Food and Drug Administration and the U.S. Environmental Protection Agency issued a joint consumer advisory on the subject in 2004. "Consumers should know that fish and shellfish can be important parts of a healthy and balanced diet," it stated. "As a matter of prudence, women might wish to modify the amount and type of fish they consume if they are planning to become pregnant, pregnant, nursing or feeding a young child."
The advisory recommends that those at-risk groups avoid eating shark, swordfish, king mackerel and tilefish but encourages the consumption of up to 12 ounces – about two average meals – a week of fish and shellfish that are lower in mercury such as shrimp, canned light tuna, salmon, pollock and catfish. (The advisory can be viewed at http://www.fda.gov/bbs/topics/news/2004/NEW01038.html.)
"Keep in mind that there has never been a reported case of mercury poisoning from seafood consumption," Tom said. "People ought to be more concerned about the risks associated with eating raw fish."
The biological hazards associated with the consumption of raw or partially cooked fish, especially shellfish, include some nasty bacteria such as Listeria monocytogenes, Vibrio vulnificus and Shigella; viruses like hepatitis and Norwalk; and assorted parasites and protozoa – tapeworms, flukes, cryptosporidium and giardia. These microorganisms and naturally occurring toxins can cause a variety of ailments – from flu-like symptoms to debilitating skin conditions and in extreme cases even death. Contrary to popular myth, some trendy dishes such as pan-seared fish and ceviche do not kill off all the potential pathogens in the center of the food.
Seafood is delicate and can spoil easily. When a fish is pulled out of the water and killed, millions of bacteria begin to breakdown its flesh. As the bacteria grow and multiply, they produce compounds causing that "fishy" smell. Other spoilage bacteria cause fish tissue to soften, further reducing quality. In certain species such as tuna, mahi mahi and bluefish, spoilage bacteria and enzymes break down protein tissue and cause the formation of histamines that induce an allergic reaction in some people.
"High-quality seafood should not smell fishy at all," Tom said. "If it smells fishy, don't buy it. High-quality seafood should appear shiny and firm and smell like fresh ocean air."
Knowing how to spot incipient signs of spoilage is science groomed to an art in the world of government sensory analysts or "noses." Tom works with the top noses in the country at the U.S. Food and Drug Administration and the U.S. Department of Commerce Seafood Inspection Program in offering sensory evaluation workshops. Their expertise is in increasing demand with seafood importers, brokers, processors and regulators. More than 80 percent of the seafood consumed in the United States is imported from about 160 countries, and that figure is expected to increase as Americans eat more seafood each year.
The sensory evaluation workshops have taken place in a number of California locations and elsewhere in the coastal United States. More recently, Tom and the noses traveled to Thailand and Vietnam. "That's where most of our seafood comes from," she says. "We were invited by the Vietnamese Association of Seafood Exporters and Producers to come share our knowledge with quality-control personnel, inspectors and university academics. We had 37 people in one class and 40 in another."
People attending these fee-based, self-supporting workshops learn how to rate the quality of popular seafood products such as tuna, mahi and shrimp on a scale from one to 100 and to use terminology developed by expert sensory panels to describe what they're experiencing. An aroma of "slightly sweet cucumbers" would score higher than "rotting onions," obviously. Does that tuna steak leave a clean aftertaste or is there something a tad rancid?
"What we're trying to do in these workshops is calibrate the human nose," she said. "Although there are electronic noses available for gauging seafood sensory quality, they are labor intensive and can be expensive to operate. Relying on the extraordinary sensitivity of the human nose is still the easiest and quickest method."
Seafood has a very good track record for safety. According to the Centers for Disease Control and Prevention, the number of seafood-borne illness outbreaks is small and is decreasing. During the 15-year period between 1973 and 1987, there were 3,703 food-borne outbreaks of disease reported through the CDC's surveillance system. Of these outbreaks, 5.7 percent of them were attributed to shellfish and 14.7 percent were reportedly caused by finfish. In a subsequent five-year period (1993-1997), shellfish accounted for only 1.7 percent of the outbreaks and finfish 5.1 percent.
Put another way, your chances of illness are one in 2 million servings of seafood when raw or partially cooked shellfish (oysters, clams and mussels) are excluded. For all seafood, the figure is one in 250,000. For raw shellfish alone, which accounts for 85 percent of all seafood-related illness, the figure is one in 2,000. By comparison, the risk is one in 25,000 servings of chicken. This risk assessment was developed by the CDC and the FDA in a 2001 report.
One of the main reasons seafood in the U.S. is safe has a great deal to do with a monitoring system known as Hazard Analysis Critical Control Point (HACCP). The seafood industry has been aggressive in implementing this proactive approach to eliminate conditions conducive to harmful microorganisms and other potential biological, chemical or physical contaminants. Tom conducts workshops and short courses on seafood quality and safety for processors, retailers and commercial laboratories and also gets the HACCP message out through an internet email list that currently has more than 900 subscribers.
Many of them like Mas Hori, a former seafood investigator and supervisor with the California Department of Health Services, Food and Drug Branch, and now a HACCP coordinator in private industry, appreciate the fact they've got some place to turn for science-based information. Hori took a "train-the-trainer" course in 1996 and has since taught most of the Southern California seafood processors, dealers, distributors and others how to implement and document measures to ensure product safety and quality.
"Sea Grant has been instrumental in helping me with the technical information I need to help the processors I work for maintain control and safety of their seafood products," Hori said. "Most seafood businesses are small and can't afford the quality control staff of a large food processor, so having access to sound information is crucial."
Hori"s sentiments are echoed by Robert Ross, executive director of the California Fisheries & Seafood Institute, the nation's largest regional trade organization representing members of the consumer seafood supply industry. "Simply put and not to overstate it, Pamela Tom is to many of our members a superstar who knows seafood technology issues and how the issues can be applied to every day industry practices," he said. "She is admired by the seafood industry and has helped make seafood handling practices better and has enhanced consumer confidence and demand for seafood as an increasingly healthy part of the American diet."
More than 350 commercial species of fish from throughout the world are available in U.S. markets. Tom is one of the people working behind the scenes to make sure that fish is safe and wholesome when it arrives at the fish counter of the neighborhood grocery store.
"Consumers need only practice variety, moderation, sanitation and proper cooking and holding temperatures," she said. "Advances in seafood technology and education continue to make seafood an excellent source of protein. The fact is it's one of the healthiest food choices you can make."
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