Cyanobacteria in the sixth Great Lake: geospatial pigment mapping and phytoplankton community composition in Mississquoi Bay, Lake Champlain

摘要

Geospatial pigment mapping is feasible and could be applied at large or small scales for first-tier monitoring of algal blooms. Relationships between temperature, community composition, and blue-green pigments in Missisquoi Bay are complex. On a given date, a large dense bloom with potential for toxin production may occur where a temperature threshold is reached, but not in every patch. Furthermore, on a given date, blooms within the bay vary with respect to species composition. This suggests that bloom formation is individualistic and controlled by numerous factors with a threshold temperature acting as a trigger. Further research on bloom formation driving factors is needed to assess relationships between blue-green species composition, environmental cues for bloom formation, seasonal patterns, and toxin production. Future lake assessment protocols for toxins and public health alerts should consider spatial variability in bloom size, extent, species composition, and toxin level prior to alerting entire water bodies to potential health risks. Current alert systems often ignore spatial scale and rely on simple triggers from fixed sample sites to develop alerts for entire water bodies.