David Tarnas represents House District 7 (North Kohala, South Kohala and North Kona) and is Chair of the Hawai'i State House Committee on Water and Land. As Chair, Rep. Tarnas works to pass legislation that strengthens the State's capacity to manage our oceans, coasts, and watersheds sustainably and adapt to sea level rise and other impacts of global climate change. Working closely with State Senator Lorraine Inouye (Chair of the Senate Water and Land Committee) in the 2021 legislative session, Rep. Tarnas was able to gain approval for major long-delayed legislation as well as innovative resource management policy reforms. On World Oceans Day, state leaders said 2021 was the most productive legislative session for ocean policy in over twenty years. During a bill signing ceremony for numerous sustainability bills passed in 2021, the Governor said this was a banner year for environmental legislation, and acknowledged Rep. Tarnas' leadership.

Returning to the State House after twenty years, Rep. Tarnas was elected in 2018 and now is in his second term as a returning State Representative, having previously served as the State Representative for Kohala and Kona from 1994-1998. He has lived in the district for over 35 years.

Rep. Tarnas and his wife, Carolyn Stewart, raised two children in Waimea, one of whom is currently a public health graduate student and the other is a planetary science post-doctoral fellow. Rep. Tarnas is a professional environmental planner with a local firm that he and his wife Carolyn formed to provide community planning, natural resource management, watershed management planning, impact analysis, permitting, compliance monitoring, reporting, government and community relations. For more than two decades, Rep. Tarnas has worked as a planner and meeting facilitator on projects in Hawai'i to develop harbors, highways, farms, ranches, fishponds, and forest plantations, as well as scientific research facilities and renewable energy projects.

Rep. Tarnas is co-author of the Hawai'i Ocean Resources Management Plan (1990), co-founding board member of Malama Kai Foundation, former UH Sea Grant Extension Agent for West Hawai'i, and author of Act 306, the 1998 law which created the West Hawai'i Regional Fishery Management Area. Over his career, Rep. Tarnas has served as a member of the Hawai'i County Agriculture Advisory Commission, member of the Community Advisory Group for the U.S. Army Garrison - Hawai'i Pohakuloa Training Area, and as the Hawai'i County Chairman of the Democratic Party of Hawai'i.