Can Anglers Reduce Their Mercury Exposure?

This 83 cm long Lake Trout was caught in Telaquana Lake in Lake Clark National Park & Preserve.

NPS / D. Forster

State and federal agencies offer general guidance to help people reduce mercury exposure from eating fish. However, many rural fishing areas lack guidance tailored to specific locations. Late in 2025, scientists from the U.S. Geological Survey and National Park Service completed a study of Lake Trout from ten lakes in four of Alaska’s national parks (Gates of the Arctic National Park and Preserve, Wrangell-St. Elias National Park and Preserve, Lake Clark National Park and Preserve, and Noatak National Preserve). We examined whether visible fish characteristics could indicate mercury concentrations, with the goal of providing practical advice to people who fish and eat Lake Trout from waters without local mercury guidance. Our study found that mercury exposure can be reduced by harvesting Lake Trout <70 cm long from surface waters, or by choosing Lake Trout with heads <25% of their body length from any depth.

Laske, S. M., D. B. Young, K. K. Bartz, V. R. von Biela, and M. P. Carey. 2026. Indicators of mercury concentration in Lake Trout: Can fish location and appearance provide information to anglers to reduce their exposure? North American Journal of Fisheries Management. 46(3).

Tags: gates of the arctic national park & preserve, lake clark national park & preserve, noatak national preserve, wrangell - st elias national park & preserve, alaska, science articles, mercury contamination