Hypoxia Research Programs

Hypoxia, or low dissolved oxygen, occurs when the amount of dissolved oxygen in water becomes too low to support most aquatic life (typically below 2 mg/l). Hypoxia is a globally expanding problem impacting aquatic ecosystems and although hypoxia can occur naturally, it is often a symptom of degraded water quality resulting from man-made activities (e.g. nutrient pollution). Common sources of nutrient pollution include agricultural runoff, the burning of fossil fuels and wastewater treatment discharges. Over half of US estuaries experience natural or human-induced hypoxic conditions at some time each year and the frequency and duration of hypoxic events have increased exponentially over the last few decades.

Hypoxic waters can become dead zones or lifeless as mobile animals that can escape, move to other areas and those that cannot often die. Sub-lethal effects also occur to organisms in the affected areas and can include cell damage and other oxidative stresses, endocrine disruption, reproductive impairment, and impacts on behavior or movement. These effects can indirectly influence health or survival and over the long term, animal populations and commercial and recreational shellfish and fisheries decline within hypoxic zones.