An extremely toxic Microcystis bloom on a pond in the Padre Island National Seashore was associated with a significant mortality of redhead ducks (Aythya americana). The primary concern is the mortality of redhead ducks that use this region as a major wintering ground. The NCCOS Event Response Program has funded a researcher from Texas A&M University Corpus Christi, partnering with the National Park Service. They plan to treat the pond with hydrogen peroxide, which selectively kills cyanobacteria and degrades the toxins.

An additional threat of the bloom is to other migratory fowl and local fauna that use the pond as a freshwater drinking source. Since little is known about the trophic transfer of microcystins, a secondary concern is the potential impact to the local ecosystem when scavengers eat dead ducks. Given thelack of knowledge about the long-term persistence of the toxin in exposed ducks, the potential threat to human health due to the redhead duck popularity with mid-western hunters is also being considered.

While hydrogen peroxide is generally considered safe, researcherswill test the minimum effective dose in pond enclosures that mimic natural conditions before treating the pond and carefully monitor water quality and toxicity in the enclosures and later in the pond. They will take various precautions to minimize treatment impacts to other aquatic life and wildlife in the area.

While the NCCOS Prevention, Control, and Mitigation of HABs program funded research on HAB control since 2010, this is the first Event Response award for HAB control.

For more information, contact Quay.Dortch@noaa.gov.