Vol. 15, No. 1, Fall 2001

Changing Waters

Jacquelyn Ross

As a child, one of my favorite activities was fishing on Clear Lake with my father. An expert fisherman, he has "fish patience" and optimism and so he would wait a long time for the fish to nibble before moving the boat to more promising locations. He would pull the old oars back to glide gently across the water and hover above another catfish hole set back in the tall shade of the tules. Sometimes we would talk a little; more commonly we would sit quietly, soaking up the deep green stillness of the water, watching the shadows of the fishing lines shift on the surface, looking down to catch a glimpse of fin, waiting for the fish to strike. When a big fish came around and took some interest in the bait, Dad would begin a low-voiced narrative of the action. "He’s coming in now. See the line move? Coming in, coming in…Get ready now…he’s going to hit fast. There he goes! Okay. Pull ’im up! Steady now. Now." Success! Whew.

During a break or after the fishing, we’d have something to eat, fruit and maybe some sandwiches. Every so often, Dad would bring along a steel tub with grill and charcoal briquettes. Barbecuing hot dogs out on the water in the boat seemed forbidden somehow and therefore added to the sense of adventure. After several hours of fishing, we would go back to the launch, put the boat back on the trailer and head home with channel catfish, crappie, or perch. There would be fresh fish for supper that night, sweet and clean-fleshed. Mom would often remark on how the Clear Lake fish tasted so good, unlike the muddy-tasting cats she remembered from her Midwest childhood. This always made us feel good, like maybe it had something to do with the fishermen.

You see a lot of people fishing, not only in lakes and not just in the country but in the cities, off bridges, municipal piers, and docks. If water and fish are around, there seems to be a magnetic draw to toss in a hook and line and catch some dinner. As it turns out, those fresh fish we so enjoy may contain a little something extra. I was in college before I bothered to look closely at the California Department of Fish and Game (DFG) regulations in detail. And then I saw the section "Public Health Advisories on Fish Consumption." Clear Lake. Oops.

Why is a health advisory on fish needed? Fish are full of protein, low in saturated fat, offer good nutrition, and are delicious. Quite commonly, health and dietary guidelines advocate eating fish as a protein replacement for high-cholesterol and high-fat meats. In short, fish are good for us. They are a part of traditional diets for numerous tribes in California and beyond. What could be wrong with them?

The problem does not start with the fish but with contaminants in the water. Over the years of industrialization, our water has been poisoned. In California, two main contaminants are PCBs (polychlorinated biphenyls) and methylmercury. Other contaminants may include pesticides, herbicides, fuel additives, and chemicals from spills, agricultural runoff, or deliberate dumping of hazardous materials. In Canada and the far north, cadmium is revealed to be a significant contaminant in the livers and kidneys of moose and caribou. If you are highly dependent on natural foods from your local lake, river, bay, or stream and know of or suspect that there are contaminants in your water systems, it might be wise to examine what you eat and how you prepare your food.

The Flight of the PCBs

The Office of Environmental Health Hazard Assessment (OEHHA) defines PCBs as "a large group of industrial chemicals with a common structure. They are oily liquids or solids, clear to light brown in color, and have no smell or taste." PCBs are sneaky. Volatile PCBs can exist as a vapor, and through evaporation and rain, they can cycle between air, water, and soil. This allows them to travel and they are now found in humans in every industrialized country in the world. Before the halt of PCB manufacture in 1977 (due to evidence of harm to health and the environment) they were used to make electrical equipment ranging from transformers to household appliances, pesticides, protective wood coating, inks and dyes, and a number of other substances and goods. PCBs are fairly resilient and do not break down quickly. They have made their way into the soil, sediments, water, and air. This could have happened for a number of reasons: damage of the goods they were a part of, poor handling and accidents in transport and disposal, and leaks from hazardous storage, for example.

In a contaminated body of water, insects, tiny animals, and plants absorb PCBs. At this point, it is helpful to know two terms, bioaccumulation and biomagnification. When a substance bioaccumulates, it stays in its host and builds up over time as the result of ingesting contaminated food, or other mechanisms. In comparing young fish and older fish in a contaminated fishing hole, the older fish will have a higher concentration of contaminants. In biomagnification, the contaminant load is passed up the food chain from insect, small animals or plants to whoever is next in line. If a small fish is eaten by a bigger fish, the bigger fish now has the PCBs. Top predators will have the heaviest load.
PCBs, like some other contaminants, both bioaccumulate and biomagnify. They settle in fatty tissue in their animal and human hosts. It is suspected that PCBs can be passed from human mothers to a baby in the womb through the placenta. It is known that PCBs pass through to nursing babies through breast milk, which is a rich fluid high in fat. This is not a reason not to breastfeed your child. If you suspect you have had significant levels of PCB exposure, you should talk to your doctor about breastfeeding. Women of childbearing age and pregnant and nursing mothers are urged to be extremely cautious about eating fish from tainted areas. Some cautionary notices advise that women stop eating fish for up to a year prior to an anticipated pregnancy. Young children and babies have much lower tolerance for toxins than do adults and are at higher risk. According to the OEHHA suspected effects of PCB contamination in humans include cancer, gastrointestinal discomfort, anemia, fatigue, and acne-like skin irritations. In children, lighter birth weights and delayed development of mental function and muscle coordination are suspected. In animals, PCBs affect the liver, stomach, thyroid glands, and reproduction.

Mercury Falling

The other big culprit is mercury, which appears in California waters as methylmercury. This means that it has gone through a methylization process and is now part of a larger hydrocarbon molecule. There are also inorganic forms of mercury (elemental mercury). The OEHHA states "Mercury is released from the earth as a vapor, condenses in clouds, and then falls in rain. Rain water runs off the land, also carrying with it mercury from soil and rocks, and particularly from tailings from abandoned mercury mines." In California, especially in the Coastal Range, mercury was mined in the form of cinnabar ore. This was converted to liquid metallic mercury that was then used to extract small amounts of gold from ore in the Sierras. Now there is contamination at many of these mining sites in both the Coastal Range and the Sierras. Industrial sources such as paper making, burning of fossil fuels, and large-scale earth disturbances such as mining and dam building can also increase the amount of mercury in our environment.
Mercury biomagnifies. Animals at the top of the food chain carry a heavy mercury load. Large and long-lived fish, including shark, swordfish, and channel catfish, are likely to carry these larger loads. If your diet is high in fish or shellfish that come from mercury-contaminated waters, you may be exposed to higher mercury levels. This poses a particular dilemma for our cousins in the north for whom marine mammals such as whales, walruses, and seals are a mainstay of traditional diet and culture.
Methylmercury is very dangerous to children and can cause problems with the mind, muscles, coordination, heart rate, blood pressure, and even brain size. This contaminant can be passed to children through placenta and breast milk. Again, talk to your doctor about breastfeeding if you have had mercury exposure. In adults, large or long-term exposure to methylmercury can result in damage to the nervous system and to the kidneys.

Rules to Live By

The health advisories issued by the California Department of Fish and Game and the Office of Environmental Health Hazard Assessment pinpoint specific areas of the state where people need to be cautious in their fish consumption because of contaminants in the waters and the capacity of certain species to bioaccumulate. The site-specific consumption recommendations are sobering, especially if viewed in terms of someone who may eat local fish as a regular part of their daily or weekly diet for reasons of preference, self-sufficiency, or economy. Some advisories note a poundage limit for consumption during any given month, usually one to three pounds depending on the species and the size of the fish. Other guidelines may simply recommend a one or two meal limit of fish for a month. In this context, a meal means eight ounces of fish. (A piece of fish the size of a deck of cards is about six ounces. Some people would call that an appetizer!)

Different advisories have been issued for different parts of California. In Clear Lake and Lake Berryesa, due to elevated mercury levels, nine fish species are on the advisory list. These include largemouth and smallmouth bass; white and channel catfish; rainbow trout, brown bullhead, Sacramento blackfish, crappie, and hitch. Carp is not listed here for Clear Lake but some people do eat them. Carp appear as a "less safe" fish on a cautionary notice for the Lake Erie Basin. An advisory exists for the San Francisco Bay and Delta Region because of mercury, PCBs and other chemicals, with sturgeon and striped bass as named species. In the Salton Sea (Imperial and Riverside Counties), croaker, orangemouth, corvina, sargo, and tilapia are listed. Los Angeles and Long Beach harbor have recommended limits for white croaker, queenfish, surfperches, and black croaker.

The overall list is daunting and more than a little discouraging, yet not having this information can be dangerous. If you or your tribe are not sure about the water in your area, seek testing. If you feel like a "lone wolf" in your concern about water contaminants, there are private companies that analyze water samples for a fee. Before you take this step, contact a state office such as the OEHHA to see if testing is in progress or planned for your area.

Ecologist/Conservation biologist Don Hankins (Plains Miwok/Osage) is concerned about water quality and the restoration of marshlands in areas once abundant in native wildlife and fish. He notes that he has seen hunting and fishing publications that recommend limiting one’s intake of waterfowl because of related chemical and elevated contaminant levels. Hankins says, "It’s important to be up front and bold about the hard facts of chemical dangers for Indian country and the general public. We need to recognize those life cycles from the smallest organism to the largest in the way our ancestors did and understand how our actions at any point in that cycle will impact the system (which we are part of) as a whole." As part of his personal commitment, Hankins is studying the tradition of fire ecology as a viable tool for restoration and for reduction in the common use of chemicals to manage pests and weeds.

I eat fish and shellfish and enjoy them, but I am more careful now about all my food than in my younger years. (See "Fish Tips.") Although this article focused on fish and water in California, contaminants have found their way around the world. Sound cautionary principles can be applied to other traditional foods and environments. While the health implications are troubling for all, they are especially so for indigenous people whose bodies run best on traditional food. Highly-processed foods such as dairy products, white sugars, and white flours make some people quite ill. A return to traditional foods is often advocated in overall plans for improved well-being and physical stamina. When our fish, plants, and animals are threatened, where do we turn? Protection and restoration of our natural places should be among our highest priorities if we are serious about interdependence and good health. Know and protect the sources of your food.

Complete information about the health advisories and can be found at the Department of Fish and Game and OEHHA websites listed in the accompanying resource list.

Thanks and Resources

The author wishes to thank Robert Brodberg of the OEHHA and Don Hankins for their generous discussions on this topic. Thanks to Liz Hankins for website resources.

Most of the technical information for this article came from the following sources:

California Department of Fish and Game www.dfg.ca.gov
Health advisory sites and lists

Office of Environmental Health Hazard Assessment
PETS/OEHHA
1515 Clay Street, 16th Floor
Oakland, CA 94612
(510) 622-3170
(916) 327-7319
Detail and Q & A on health advisories, Mussel Watch information
Centre for Indigenous Peoples’ Nutrition and Environment www.cine.mcgill.ca
Native-directed site from Canada explaining risks and benefits of traditional food

Monterey Bay Aquarium
Seafood Watch list

Agency for Toxic Substances and Disease Registry (ATSDR)
U.S.Department of Health and Human Services, Public Health Service.
1-888-422-8737
Exhaustive and understandable discussion about toxins, their effects, and responsible disposal.

Rob Whitlow and The E.A.G.L.E. Project (Effects on Aboriginals from the Great Lakes Environment)

"A Family’s Guide to Eating Fish from the Lake Erie Basin"
The Lake Erie Binational Public Forum
(312) 554-0900