Microcystin Prevalence throughout Lentic Waterbodies in Coastal Southern California

Abstract

Toxin producing cyanobacterial blooms have increased globally in recent decades in both frequency and intensity. Despite the recognition of this growing risk, the extent and magnitude of cyanobacterial blooms and cyanotoxin prevalence is poorly characterized in the heavily populated region of southern California. Recent assessments of lentic waterbodies (depressional wetlands, lakes, reservoirs and coastal lagoons) determined the prevalence of microcystins and, in some cases, additional cyanotoxins. Microcystins were present in all waterbody types surveyed although toxin concentrations were generally low across most habitats, as only a small number of sites exceeded California’s recreational health thresholds for acute toxicity. Results from passive samplers (Solid Phase Adsorption Toxin Tracking (SPATT)) indicated microcystins were prevalent throughout lentic waterbodies and that traditional discrete samples underestimated the presence of microcystins. Multiple cyanotoxins were detected simultaneously in some systems, indicating multiple stressors, the risk of which is uncertain since health thresholds are based on exposures to single toxins. Anatoxin-a was detected for the first time from lakes in southern California. The persistence of detectable microcystins across years and seasons indicates a low-level, chronic risk through both direct and indirect exposure. The influence of toxic cyanobacterial blooms is a more complex stressor than presently recognized and should be included in water quality monitoring programs.

Multiple Stressors at the Land-Sea Interface: Cyanotoxins at the Land-Sea Interface in the Southern California Bight

“…The recognition of harmful genera and occasionally toxins in streams [32], lakes/lentic water bodies [30,33], and rivers [33] that lead to the coast prompted this coordinated sampling effort at the land-sea interface. The objectives were to identify potential toxin-producing cyanobacterial taxa and to determine if specified cyanotoxins were present in detectable quantities within these brackish water ecosystems.…”

Algal Blooms and Cyanotoxins in Jordan Lake, North Carolina

“…CyanoHABs may consist of multiple forms of toxins, but limited data is currently available on where and when toxins co-occur and under what environmental conditions [ 47 , 65 , 66 , 67 ]. To our knowledge, this study is unique in providing a year-round and multi-year record that allows the confirmation of the presence and co-occurrence of four cyanotoxins (dissolved MCY, CYN, ANA and BMAA) in a US freshwater body ( Table 2 and Table 5 ).…”

The Effect of Organic Carbon Addition on the Community Structure and Kinetics of Microcystin-Degrading Bacterial Consortia

“…Furthermore, the relatively high magnitude of MC (200 µg/L) and ethanol (~300 mg/L) concentrations that were employed in this study were selected to represent worst case bloom conditions. Past sampling of lakes and reservoirs throughout the United States (U.S.) has indicated that concentrations of total MC rarely exceed 200 µg/L [78][79][80][81][82][83][84], whereas total dissolved organic carbon (DOC) concentrations ranged from 0.2 to 516 mg/L [40]. It is important to note a considerable portion of the readily bioavailable fraction of the total DOC pool may be attributed to secreted algal organic matter, especially in HAB impacted environments [38,39].…”