Protect Our Fisheries: Pesticide No-Spray Buffer Zones

photo of salmon swimming underwater

Fried fish sticks and fillets aren’t the only seafood on concession menus these days. With park visitors expecting healthier and more varied fare, it’s just as likely that a delicious salmon or steelhead entrée will make it to the dinner table, even in landlocked national parks.

The future is looking a little brighter for six species of Pacific salmon (five of which are commercially caught) and steelhead trout that spawn in California, Oregon, and Washington rivers. The United States Environmental Protection Agency (USEPA) has reinstated streamside no-spray buffer zones for five commonly used pesticides in West Coast waters that support endangered and threatened salmon and steelhead. This should help with increasing Pacific salmon populations from those particular rivers and streams. (Note: Wild-caught Pacific salmon and steelhead come only from healthy fish runs.)

To support the ruling, concessioners operating in California, Oregon, and Washington must ensure that they are not using or planning to use products that contain carbaryl, chlorpyrifos, diazinon, malathion, and methomyl within 20 yards of salmon-supporting waters for ground pesticide applications and 100 yards for aerial pesticide applications. For a specific look at where these pesticides cannot be used, look at the USEPA-developed Salmon Mapper, an interactive map that illustrates specific waters affected by the no-spray buffer zones for each pesticide.

As concessioners are already required to obtain permission from parks annually on what pesticides are planned to be used, there should be little chance that the five pesticides of interest would be improperly applied in the parks. Regardless, concessioners should review their pesticide stocks to identify which of their products might contain any of the pesticides below so that their potential use can be reported to the parks and carefully controlled.

  • Carbaryl is an insecticide used to control a wide variety of pests, and has been used to treat lawns, ornamental plants, trees, and building foundations. Over 300 products containing carbaryl are actively registered with the USEPA, but some of the most common ones are SevinTM, AdiosTM, CarbamecTM, and SlamTM. Its toxicity to fish has a wide range.
  • Chlopyrifos is an insecticide that treats many different kinds of pests, including termites and mosquitoes. Its only legal indoor use is in containers with treated baits, but it is also used on golf courses and other areas to control fire ants and mosquitoes. It is very toxic to fish.
  • Diazinon is an insecticide used in agriculture (residential and indoor uses of diazinon were cancelled in 2004). Old stock of residential and indoor use of diazinon – whether in dust, granule, liquid, or concentrate form – could be stored at concessioner facilities. It is moderately to highly toxic to fish.
  • Malathion is an insecticide commonly used outdoors to control mosquitoes. Thousands of products contain malathion. It is moderately to highly toxic to fish.
  • Methomyl, also known as metomil and mesomile, is a classified Restricted Use Pesticide. As a broad spectrum insecticide, it is used on commercial ornamentals. It is moderately to highly toxic to fish.

Of course, the best option is to avoid using pesticides in the first place, if at all possible. Park or regional integrated pest management coordinators can assist in this effort to help protect the health of our wildlife and fisheries, and people too! Contact your IPM (or concession specialist) if you have questions on how to responsibly manage pests affecting concession operations.