Wadeable streams as widespread sources of benthic cyanotoxins in California, USA

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

“…Moreover, research on phytoplankton toxins in Southern California has largely focused on marine algae because of increased awareness resulting from visible manifestations of these blooms, and their correlation with wildlife mass mortality events for nearly two decades [43,44]. In contrast, the widespread distribution of potentially toxic cyanobacteria in freshwater ecosystems across the region has been recognized only recently [32]. As a consequence, scientific recognition and understanding of the importance of cyanotoxins of freshwater origin in estuaries throughout the Southern California Bight (and an unknown number of other regions globally) has significantly lagged behind our knowledge of marine systems.…”

“…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.…”

Benthic soft-bodied algae as bioindicators of stream water quality

“…Qualitative analysis of additional fresh samples is an important step for identifying macroalgae, because large amount of algal material is observed including reproductive structures. Fresh samples allow isolation, culturing and molecular studies on species of interest, such as taxonomically problematic genera (e.g., Zygnema and Spirogyra (Stancheva et al, 2012c(Stancheva et al, , 2013a, rare, sensitive and potentially endemic species (Wehr et al, 2013), or nuisance algae and harmful cyanobacteria (Fetscher et al, 2015). This methodology, although time-consuming, enhances the power of water-quality assessments by better knowledge of local algal flora .…”

“…Benthic chlorophyll values above 100 mg·m −2 have been considered excessive, representing a critical level for an aesthetic nuisance (Welch et al, 1988). As system becomes more productive, different species of algae become more competitive, including toxin-producing cyanobacteria (Fetscher et al, 2015), and species composition shifts occur. Usually, nuisance algal growths in streams and rivers are monitored by quantitative sampling of algal biomass.…”

“…In addition, algal-nutrient interactions are discussed in the light of their bioindicator potential. Examples are included from our research experience incorporating soft-bodied algae in stream bioassessment in California as part of the Surface Water Ambient Monitoring Program of the California State Water Resources Control Board (SWAMP, http://www.waterboards.ca.gov/water_ issues/programs/swamp/) (Stancheva et al, 2012a(Stancheva et al, ,b, 2013a(Stancheva et al, ,b, 2014Fetscher et al, 2013Fetscher et al, -2015Wehr et al, 2013).…”