REPORT PROJECT BACKGROUND: Golden alga (Prymnesium parvum) is a harmful algal species that is primarily found in marine ecosystems but is also present and invasive in brackish inland waters. The first documented bloom of golden alga in the United States occurred in the Pecos River in 1985. This species has since invaded other water bodies in the Pecos River basin (e.g. sinkhole habitats, reservoirs) and has been reported in at least 23 U.S. states. Toxins produced by golden alga can be lethal to fishes, bivalves, crayfish, and gilled amphibians. The ecological and economical impacts of golden alga blooms have been severe. Recent research suggests that the frequency and severity of golden alga blooms will increase under altered flow regimes as a result of climate change; however, the mechanisms leading to bloom formation and toxicity are complex and not well understood.
The primary goal of this research is to enhance our understanding of the environmental conditions, specifically water quality variables, which promote or regulate golden alga presence and bloom formation in the Pecos River system. Our approach included sampling a wide range of habitats and environmental conditions throughout the middle and lower Pecos River basin within the Desert LCC region, and across an 18-month time-span to account for seasonal events. A suite of statistical techniques were used to relate occurrence of golden alga to environmental variables and identify specific water quality attributes that are associated with or promote golden alga bloom development.
Results of this research are expected to benefit managers of the Pecos River watershed and of its resident aquatic biota. More specifically, the information obtained may assist in the development of surface water quality criteria either to prevent or to mitigate conditions that result in toxic algal blooms.
Research conducted under the auspices of Bureau of Reclamation Agreement # R11 AP 81 529 was part of the master’s thesis project of Ms. Natascha Israël, which also addressed additional research objectives. The portion of the research pertaining to the agreement was extracted from Ms. Israël’s thesis and formatted into standard manuscript form for the purpose of future publication. This manuscript has been reviewed following U.S. Geological Survey’s FSP procedures and approved for release (IPDS # 052901).
