Performs work requiring a professional knowledge of fishery biology. Develops, conserves, manages, and administers fishery resources. Evaluates impact of construction projects and other socioeconomic activities presenting potential or actual adverse effects on fishery resources and their habitat. Determines, establishes, and applies biological facts, principles, methods, techniques, and procedures for production and/or management of aquatic resources in their natural habitat and/or within facilities and systems constructed for their benefit and public use.