Tips on Fishing and on Selecting Healthful Fish

tuna and salmonGone fishing yet this summer? No?  Well, before the pleasant weather ends, you may want to try it--unless, of course, hooking worms makes you squirm.  If so, the alternative is to go fishing at your local grocery or fish store.  There, you have many types of fish to choose from. Below is the scoop on the most--and least--healthful ones. Wherever your fish dinner comes from and whatever it is, safe handling is extremely important to minimize contaminants of various kinds. Read on for many tips on all these fish-related matters. 


Fishing for Fun and Food


Much of the following advice on safe handling of fish comes from an Extension brochure entitled "Proper Care and Handling of  Fish from Stream to Table" written by food scientist Dr. Catherine Cutter, a faculty member of Penn State University's College of Agricultural Sciences and a member of this site's Advisory Board.


First and foremost, toss your line into safe waters. Before choosing a fishing site, do some research on the bodies of water you're considering for your excursion. Find out about contaminant levels by contacting your local health department, state fish advisory board, or environmental conservation office. Take the advice seriously.  If no advice is available about the fishing site(s) you're considering, the EPA (Environmental Protection Agency) recommends that children eat no more than 3 ounces per week from that location and adults no more than 6 ounces per week.


If you're fishing for sport but not for dinner, release the fish immediately after you catch it because that will improve its chances for survival. To catch a fish you plan to throw back in the water, you need only basic equipment (a pole, hook, and bait) plus a knife to cut your catch(es) loose.  If you're willing to do it, it's probably better to leave the hook in the fish and just cut the line close to the hook, food scientist Dr. Joe Regenstein (another Shelf Life Advice Advisory Board member) advises.


On the other hand, if you're fishing for dinner, keep this in mind: your "free" meal may not be so free. To fish in almost all freshwater areas in the U.S., you may need a fishing license.  In addition, if this is your first venture into this sport, you need to make a number of purchases.  Here's Dr. Cutter's list of  some equipment you may need: a sharp fillet knife, a whetstone or steel for sharpening the knife, clean cloths or paper towels for handling the fish, sealable storage bags, disposable plastic gloves, a cooler full of ice or snow, and a bucket, basket, or stringer or live box to keep fish alive. Of course, you also need food and drink to give you something to do while you wait for fish to bite. I also recommend a bucketful of patience and a loquacious companion. (It's okay to talk while you're fishing, says Dr. Regenstein.


Also one of our Advisory Board members, food process engineer, Dr. Timothy Bowser, says the following about handling fish you catch and plan to eat: "Keep them alive as long as possible.  When you're ready to go home, gut and clean the fish and put them on ice immediately.  This means you must be prepared with ice (or frozen gel packs), a cooler, a clean knife, and a cutting board."


Dr. Cutter's brochure gives specifics about the surgical procedures you should perform on your future entrée. (Consult the "After the Catch" and "Transporting and Processing Fish" sections of the brochure).  If, when it comes to killing and cleaning fish,  you're squeamish, inexperienced, confused, or clumsy with a knife, be sure the  loquacious companion by your side has some expertise in dealing with this messy process. 


Some other important pieces of advice in Cutter's article:


After the catch, do the following:

  • When cleaning the fish, remove the skin and fat deposits. Pesticides or other harmful substances may be concentrated in fatty parts of the fish.
  • Quickly cool fish to 35-40°F to prevent bacterial growth.


In the kitchen, take these steps:

  • Thaw frozen fish in the refrigerator or in the microwave.  If microwaving, cook the fish immediately thereafter.
  • If you're marinating the fish, do it in the fridge, not on the counter.
  • Cook all fish until it's flaky and reaches 145°F to reduce the risk of foodborne illness.
  • Fatty fish (such as salmon, tuna, and trout) can be dipped in ascorbic acid (2 tbsp. to 1 qt. water) to control rancidity and flavor change.
  • Lean fish (such as flounder, cod, and snapper) can be dipped in brine (1/4 cup salt in 1 qt. cold water) to firm fish and decrease drip loss upon thawing.
  • Raw fish should be stored in a covered container and cooked and served within 2 days.



Why Eat Fish? Which Fish Should You Be Eating?


Fish are an important part of a heart-healthy diet.  The federal government's recent (June 2014) draft advisory says that pregnant women and young children especially need to increase fish consumption "in order to gain important developmental and health benefits." Fish have "important nutrients that can have a positive impact on growth and development as well as on general health."  The advice (from the FDA and EPA) is that pregnant women eat at least 8-12 ounces (2-3 servings) per week of fish that are low in mercury. 


Mercury levels and their risks:


Mercury contamination in humans comes mostly from the food they eat. Although concentrations of mercury are in many foods, the amounts are negligible compared to the quantity in fish.  All kinds of fish contain some mercury. Mercury gets into fish when industrial pollution contaminates the water they live in. Larger fish also get mercury from the smaller fish they consume. Therefore, mercury levels tend to be higher in larger fish.


The government recommends that people eat seafood or fish lower in mercury such as shrimp, pollock, salmon, canned light tuna, tilapia, and cod. The government also recommends that pregnant women, nursing mothers, women of child-bearing age, and young children all avoid fish that are high in mercury such as shark, swordfish, king mackerel, tilefish, and other large species.  The Chicago Tribune also points out that the FDA/EPA doesn't mention these popular fish that contain significant amounts of mercury: orange roughy and Chilean sea bass.


Why is it so important to avoid mercury, especially for fetuses and young children?  Methylmercury, the most toxic type of mercury, can affect the immune system, alter genetic and enzyme systems, and damage the nervous system, including coordination and the senses of touch, taste, and sight.  Chicago Tribune gives these scary specifics:  "Studies have shown that exposure to mercury in the womb, mostly from fish eaten by women, can irreversibly damage the brain before a child is born, causing subtle delays in walking and talking as well as decreased attention span and memory.  Some research suggests that mercury also can increase the risk of heart disease in adults."


How much mercury is too much for people to consume?  There is no simple, one-number answer. The role of selenium (which is in the human brain and is found in different amounts in different fish) must be considered.  Selenium can neutralize some of the harmful effects of mercury, Dr. Regenstein points out.  But scientists have different opinions about the quantity of selenium needed to make a fish dish safe to consume. How much canned tuna is it safe to eat weekly? In addition to the quantity of selenium, many factors must be considered, such as the type of tuna and the age and weight of the person.  To read more about this controversial, complicated matter, check out these articles:  "Consumer Reports misses mark on mercury" and "Toxic Tuna: Does Selenium Cancel Out Methyl Mercury?"


Forty states have issued advisories for methymercury in at least some bodies of water within their state.  Coastal areas along the Gulf of Mexico, Maine, and the Atlantic Ocean from Florida through North Carolina have methylmercury advisories for some fish. 


PCB levels and their risks:


PCBs (Polychlorinated Biphenyls) are a group of man-made organic chemicals. They were used in hundreds of industrial and commercial applications until their manufacture was banned in 1979.  These compounds found their way into the air, water, and soil as a result of improper disposal. The rate of their biodegradation is very slow; without proper clean-up, they can remain in water for hundreds of years.


PCBs are classified by the EPA as probable human carcinogens. In addition, they have been associated with many other harmful medical conditions.  PCBs can enter the bodies of animals and some plants and then get into the human body when these are consumed.  For more information about how PCBs get into plants and animals and how they might harm humans, go to the EPA link "Understanding PCB Risks."


PCBs are found in mainly meat, larger fish, the fatty parts of fish, and fish caught near industrial areas. To avoid consuming significant amounts of PCBs, the FDA advises people to eat fish that contain only small amounts of these chemicals. 


Here's how you can avoid consuming PCBs in the fish and seafood you prepare at home, according to the California Office of Environmental Health Hazard Assessment (OEHHA):  


  • Clean and gut the fish you catch before cooking it. Some chemicals, including PCBs, build up in organs, especially in the liver.
  • PCBs are stored mainly in the fat. Trim the fat, remove the skin, and fillet the fish before cooking.
  • Don't use the fat, skin, organs, juices, (or whole fish) in soups or stews.
  • Bake or grill fish in a manner that lets the juices drain away. 
  • If you eat crabs or lobsters, do not eat the soft green parts because PCBs can build up there.


According to the Wisconsin Department of Health Services, "The top level predators such as walleye and bass contain the highest amounts of contaminants. Since PCBs are stored in fat, smaller, leaner, shorter-lived species such as bluegills, crappie, and yellow perch contain very low or undetectable levels of PCBs."


Salmon--few risks, many benefits:


"Salmon is the only popular type of seafood that is both low in mercury and high in beneficial fatty acids," says the Chicago Tribune. These benefits make salmon a great choice for your fish dinner. 


Dr. Bowser tells us what kind to buy: "Wild Alaskan salmon are simply the best and probably the healthiest fish product out there. They live in pristine waters and consume an all-natural diet. There are five species available, and I haven't tasted one I didn't like. " 


Dr. Regenstein regrets the fact that, in retail stores, the particular species of salmon on sale are not identified for customers.


Dr. Regenstein also mentions the pesticides issue: "To significantly decrease the pesticide level and the level of other undesirable compounds that are fat soluble, before cooking, remove the dark muscle along the lateral line just under the skin, and cook the salmon without the skin on so that any fat drips out." [Everyone seems to agree that that fat is bad.  So why does it have to taste so good?]


The June issue of the Tufts University Health & Nutrition Letter calls the return of fresh wild salmon to supermarkets "among the many pleasures of summer." Various species of fresh wild salmon are in season from May through September.  It's America's third most-consumed seafood, preceded only by shrimp and tuna.  The Tufts University article says that, in general, the highest levels of omega-3 fatty acids are in "species like king salmon, which swim in the coldest waters."


Farm-raised Atlantic salmon has been linked to higher levels of PCBs because it is in their feed (smaller fish) they eat.  If you don't eat the skin of the salmon or the fat directly beneath it, you'll avoid a lot of the PCBs.  (Unfortunately, you'll also be cutting away some of the beneficial omega-3s).  The Tufts Letter recommends that pregnant women and those with a family history of cancer limit farm-salmon consumption to once or twice a month because of the PCB content. 


Healthful salmon is available all year round because flash-frozen salmon is as nutritious as fresh. It holds up in the freezer for about 4 months.  Canned salmon is also a good choice; the bones provide a calcium boost. Dr. Regenstein makes these bones into a powder and consumes them as part of whatever recipe he uses with the canned salmon.


Final thought: For people of all ages, the health benefits of eating fish outweigh the risks, especially for those who take the precautions suggested in this article and choose the right fish.


To learn more about fish and shellfish, go to these Shelf Life Advice links: "Fish and Shellfish" and "Zapping Our Seafood Favorites for Safety's Sake."





Timothy J. Bowser, Ph.D., Oklahoma State University, Dept. of Biosystems and Agricultural Engineering


Catherine N. Cutter, Ph.D., Pennsylvania State University, Dept. of Food Science


Joe Regenstein, Ph.D., Cornell University, Dept. of Food Science "FDA and EPA issue draft updated advice for fish consumption" "Proper Care and Handling of Fish from Stream to Table,"


USGS (U.S. Geological Survey) "Mercury in the Environment" "Slow Fish: Mercury" "Understanding PCB Risks" "Fish" "Getting your omega-3s vs. avoiding those PCBs."


Tufts University Health & Nutrition Letter, "Smart Shopping for Salmon," June 2014.


Chicago Tribune, "EPA, FDA update diet advice: Go fish," June 11, 2014. "Fish Consumption Advisories"


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