Fish Contamination Education Collaborative

What is DDT?

DDT, or dichlorodiphenyltrichloroethane, is a synthetic pesticide that was widely used in the United States until the 1970s to control insects that destroy crops and carry diseases like malaria. Montrose Chemical Corporation produced DDT from 1947 to 1982 at its plant near Torrance, California. In 1972, the United States banned the use of DDT because of its potential risks to human and environmental health. However, due to their stable chemical structure, DDT and its breakdown products (often referred to collectively as DDX) remain in the environment for a very long time.

What are PCBs?

PCBs, or polychlorinated biphenyls, are a group of synthetic chemicals that were widely used in industrial processes and products, such as electrical equipment, because of their insulating properties. Like DDT, their use was banned in the 1970s because they were found to harm human health and the environment. However, PCBs do not break down easily and remain in the environment long after their release.

How did DDT and PCBs get onto the Palos Verdes Shelf?

The Montrose Chemical Corporation plant manufactured DDT from 1947 to 1982. From 1953 to 1971, Montrose disposed of chemical waste containing DDT into the Los Angeles County sanitation sewer system. During this same period, other industries released PCBs into the sewer system. These contaminants flowed through the sewers and were released into the ocean via the White Point outfall pipes off the Palos Verdes Peninsula where they accumulated in sediments on the Palos Verdes Shelf.

How widespread is the DDT and PCBs contamination off the coast?

About 1,100 tons of DDT were deposited in ocean floor sediment on the Palos Verdes Shelf. Today, about 34 square miles of ocean sediment are contaminated with these legacy pollutants. The contamination extends along the coast from Redondo Beach, CA to San Pedro, CA. High levels of DDT and PCBs in the sediment have contaminated the local food web, leading to fishing advisories for areas between Santa Monica Pier and Seal Beach Pier.

How can you tell if a fish is contaminated with DDT or PCBs?

Fish contaminated with DDT and PCBs do not look, taste, or smell any different than fish that are not contaminated. Therefore, it is important to follow the fish consumption advisories issued by the state of California.

Where can I get more information about contaminated fish?

To learn more about state fish advisories, visit:

If you live in Los Angeles County you can call
Los Angeles County Department of Health Services: (213) 240-7785

If you live in Long Beach, you can call
City of Long Beach, Department of Health and Human Services,
Bureau of Environmental Health: (562) 570-4134

If you live in Orange County you can call
County of Orange, Health Care Agency, Environmental Health: (714) 667-3600

What are the contaminated fishing areas?

Fishing areas in the red zone include Santa Monica Pier, Venice Pier, Hermosa Beach Pier, Redondo Beach Pier, Cabrillo Pier, Pier J, Rainbow Harbor, Belmont Pier, and Seal Beach Pier. View our What Fish Are Safe to Eat page to see the full map of contaminated areas.

Which fish can I eat?

The state of California has determined that five fish species are unsafe to eat: white croaker, barred sand bass, black croaker, topsmelt, and Pacific barracuda. However, many other species are safe to eat. View our What Fish Are Safe to Eat page to see which local fish are safe for consumption.

How can I safely prepare fish?

Follow official fish consumption advisories and recommended cooking methods. You can reduce your risk by choosing which fish to eat, how often you eat them, and which parts you eat (for example, eating only the fillet to reduce your exposure). The FCEC provides tips on which parts of the fish to avoid and cooking methods that can reduce your exposure to DDT and PCBs.

Can you eat fish when you are pregnant?

Because DDT and PCBs can be especially harmful to children and developing babies, fish advisories highlight pregnant women and children as sensitive groups. It is recommended that pregnant women and children strictly follow fish consumption advisories.

During pregnancy and breastfeeding, mothers can pass chemicals like DDT and PCBs to their infants. Exposure to high levels of DDT can negatively impact child development. While some studies suggest delays in growth and development in children born to mothers with high chemical exposure, sticking to the recommended advisories for the Los Angeles and Orange County coasts will help protect your health and the health of your baby.

What is mercury poisoning and how does it relate to fish?

Some fish and shellfish contain high levels of mercury, which may harm an unborn baby or young child’s developing nervous system. Therefore, the FDA and EPA advise women who are pregnant or may become pregnant, nursing mothers, and young children to avoid certain types of fish and choose options lower in mercury.

Check local fish advisories regarding the safety of fish caught in your local lakes, rivers, and coastal areas. If no advice is available, limit consumption of locally caught fish to 6 ounces per week.

What are the health effects of eating fish contaminated with DDT and PCBs?

Eating contaminated fish does not make people sick right away. However, these chemicals can build up in your body over time and pose a risk to human health. The more contaminated fish you eat over your lifetime, the greater your risk of developing health problems.

Health effects associated with exposure to DDT and PCBs include a higher risk of cancer, liver damage, and negative impacts on the immune, nervous, and reproductive systems. These chemicals can also affect child development.

I have been eating fish caught off the coast for years. How is this affecting my health now?

It is difficult to say exactly how your health is being affected now. Whether you experience health effects depends on the type of fish you eat, how often you eat it, and which parts of the fish you consume. Generally, if you follow the fish advisories and eat within recommended limits, you minimize your chance of developing health problems related to site contamination.

If you have eaten white croaker from the Los Angeles coast on a weekly basis, for example, you may have higher levels of PCBs and DDT in your body, but that does not strictly mean you will experience immediate health effects.

Should senior citizens be concerned?

Yes. Because these chemicals can impact the immune system, senior citizens should take care to follow fish consumption advisories. It is best to follow recommended preparation and cooking practices to lower the possibility of developing health problems. You can reduce your risk by following the state fish advisories for senior citizens.

Why have I not heard of this problem before?

Fish consumption advisories have been in place since 1985 (Interim Fish Advisory) and 1991 (Final Fish Advisory) due to high levels of DDT and PCBs. While stories have appeared in local media, these early efforts may not have reached all affected populations.

In 2001, the EPA issued an Action Memorandum to implement an Institutional Controls program to increase public awareness of local fish contamination and associated health risks. In 2003, the U.S. EPA established the Fish Contamination Education Collaborative

(FCEC) to implement the public outreach and enforcement components of this program. Today, the FCEC, a partnership of federal and state agencies, community-based organizations, and local health departments, conducts outreach in multiple languages at piers, markets, and community events to ensure the message reaches those most at risk.

Are fish caught in areas outside of Los Angeles and Orange Counties safer to eat?

It is likely that fish caught further from the Palos Verdes Shelf will have lower levels of PCBs and DDT. To ensure safety, federal and state agencies conduct ongoing monitoring of fish tissue and sediment. The EPA’s most recent Five-Year Review (2024) and Monitored Natural Recovery Report (2024) continue to track contamination levels.

You should always check for fish consumption advisories in other areas through the Office of Environmental Health Hazard Assessment (OEHHA). Additionally, follow general safe eating habits: eat different types of fish from a variety of places, eat smaller legal-size fish, and cook fish so that the fat drips away (fillet the fish and remove the skin and guts). Also see more information on cleaning and cooking fish safely.

Fish advisories help people make informed decisions about which fish to eat and where to fish. These advisories recommend that people limit or avoid eating certain types of fish caught from specific coastal waters to minimize exposure to harmful chemicals.

Because some chemicals may be more harmful to sensitive groups, the advisories include specific recommendations for women and children. The EPA follows health advisories issued by OEHHA, which highlight that women and children should eat less fish than other groups to reduce their risk.

What about other seafood? Is it ok to eat crabs and shrimp caught off the coast?

Invertebrate organisms, such as crabs, live in contaminated sediment and accumulate DDT and PCBs in their bodies. These contaminants can build up in the fatty parts of shellfish. It is best to limit consumption of shellfish caught in the red zone areas (such as White Point and near the piers listed in the advisories). You should especially avoid eating the hepatopancreas (butter or tomalley) of lobster caught in these areas, as its high fat content can store unsafe levels of DDT and PCBs.

Shellfish may also be unsafe to eat due to other factors, such as paralytic shellfish poisoning or bacteria. Always check with your local health department for the most current recommendations on shellfish safety.

What effect does the runoff after it rains have on the fish?

Runoff after rain can carry pollutants like motor oil, pesticides, litter, and bacteria into storm drains and eventually into the ocean. While the DDT and PCB contamination at the Palos Verdes Shelf site are from historical disposal practices, stormwater pollution can negatively impact the general environment and sea life. Practicing pollution prevention measures helps protect our coastal waters.

If I shouldn’t eat certain fish from the red zone, is it okay to swim there?

Yes. There is no known health risk associated with swimming in the coastal areas around the Palos Verdes Shelf related to DDT or PCBs. The contaminated sediment is located on the ocean floor, approximately 200 feet below the surface—too deep for human contact. However, there may be health risks posed by swimming in waters with high levels of bacteria or viruses, especially after heavy rain. To find information on water quality for swimming, please check the Beach Report Card or the State’s Safe to Swim Portal.

How can you identify White Croaker?

White Croaker is known by several names, including Kingfish and Tom Cod. Key identifying features include 12 to 15 spines on the dorsal fin, a black spot just above the pectoral fin (the fin next to the gill), a horizontal mouth, and a slightly protruding snout. White Croaker may resemble Queenfish.

Why does White Croaker have higher levels of DDT and PCBs?

White Croaker are bottom-feeders that eat invertebrate organisms, such as aquatic worms and crabs, that live in the contaminated sediment on the ocean floor. Because they feed directly from the source of the contamination and are a fatty fish, DDT and PCBs build up in their bodies at higher levels than in other species. White croaker caught from yellow zone areas generally have lower levels of DDT and PCBs than those caught from the red zone areas.

Why can we not eat White Croaker from the red zones but can eat them from other zones?

The highest concentrations of DDT and PCBs are found in the sediment near the White Point outfalls (the red zone). Contamination levels in the water and sediment generally decrease the further you are from this source. Decades of fish sampling and testing have shown that White Croaker caught in the red zone have significantly higher levels of DDT and PCBs than those caught further away (often referred to as the yellow zone).

Because White Croaker feed directly off the ocean floor where the chemicals are located, and because these chemicals accumulate in fatty tissues, the location of the catch is critical. Following the specific consumption recommendations for the different zones will help minimize your exposure to chemicals.

How do I know that the fish I buy in the market doesn’t come from the contaminated areas?

Commercial fishing for White Croaker is banned in the area of the Palos Verdes Shelf that has the highest known sediment contamination. The California Department of Fish and Wildlife enforces this ban to prevent contaminated fish from reaching local businesses. Additionally, the FCEC collaborates with the CDFW to conduct inspections of local fish markets and restaurants to ensure that contaminated fish aren’t being sold or served to the public.

Enforcement includes inspections and seizures of contaminated White Croaker found in markets. Data from commercial and recreational inspections (2015–2022) shows that the amount of White Croaker observed has decreased significantly, helping ensure that fish sold in local stores does not come from the contaminated area.

How can you tell that the fish caught in the yellow zone didn’t come from the red zone?

It is difficult to determine exactly where a fish has been. However, species like White Croaker are bottom feeders that tend to stay in specific local areas. Because they feed directly off the ocean floor where contamination is highest, White Croaker caught in the red zone are significantly more contaminated than those caught further away. Conversely, other species listed as unsafe, such as Pacific Barracuda, may swim over larger areas but still accumulate unsafe levels of chemicals in their bodies.

Will cooking the fish remove the chemical contaminants?

Unlike bacterial or viral contaminants, cooking fish contaminated with DDT and PCBs will not completely remove the chemicals. However, proper preparation can reduce the levels of contaminants. Because DDT and PCBs build up in fatty tissues, you should:

1. Remove all fatty parts of the fish, including the skin, guts, belly fat, and the fatty dark meat along the length of the fillet.

2. Eat only the cooked fillet.

3. Bake, broil, steam, or grill the fish on a rack to let the cooking juices and fat drip away.

4. Do not use the whole fish or bones when making soups, caldos, stews, or chowders.

Will frying the fish remove the contaminants?

Cooking fish by most methods can help decrease levels of PCBs and DDT if the fat is allowed to drain away. However, frying often seals the fat (and chemicals) into the fish. It is best to bake, broil, or grill fish. Remember that preparation and cooking methods do not get rid of all the chemicals, so it is important to stay within the recommended consumption amounts listed in the fish advisories.

Note: Preparation and cooking methods do NOT decrease the amount of mercury in any fish.

Is it safe to feed fish skin and fatty parts to pets?

No. Animals can accumulate chemicals in their bodies just like humans. Feeding pets the skin, guts, and fatty parts, where DDT and PCBs are most likely to accumulate, will increase their exposure and may increase the risk of developing health problems.

Are fish eggs considered part of the guts?

Eggs (roe) are not technically organs or "guts", but they do tend to have higher fat levels. Because contaminants build up in fat, it is best not to eat the eggs to reduce your intake of PCBs and DDT.

Is it better to fish in a boat or on a pier?

It depends on the type of fishing experience you want. Generally, sport fishing charters and private boats provide access to the open ocean and deep water. Pier fishing keeps you closer to the shore and is a popular way for anglers in Los Angeles County to fish without a permit. Many fishing piers in California extend into the ocean far enough to allow for catch of legal-sized bass, halibut, and rockfish. Whether by boat or pier, fishing is an integral part of the local community and economy.