Microcystins, nutrient dynamics, and other environmental factors during blooms of non-microcystin-producing<i>Aphanizomenon flos-aquae</i>in Upper Klamath Lake, Oregon, 2009

Eldridge, Sara L. Caldwell; Wood, Tamara M.; Echols, Kathy R.; Topping, Brent R.

doi:10.1080/10402381.2013.775199

Cited by 17 publications

(5 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The death of A. flos‐aquae makes dissolved nitrogen available for non‐nitrogen‐fixing, toxigenic cyanobacteria, including Microcystis aeruginosa (Caldwell Eldridge et al. ). During the bloom‐crash period, intracellular microcystin—the toxin produced by M. aeruginosa and other cyanobacteria—can be high (≤11.8 μg/L, or ≤ 951 μg/g dry weight), but extracellular microcystin concentrations are typically low (≤3.93 μg/L).…”

mentioning

confidence: 99%

Mortality of Endangered Juvenile Lost River Suckers Associated with Cyanobacteria Blooms in Mesocosms in Upper Klamath Lake, Oregon

et al. 2020

View full text Add to dashboard Cite

Unsustainably high mortality within the first 2 years of life prevents endangered Lost River Suckers Deltistes luxatus in Upper Klamath Lake, Oregon, from recruiting to spawning populations. Massive blooms of the cyanobacterium Aphanizomenon flos-aquae and their subsequent death and decay in the lake (bloom-crashes) are associated with high pH, low percent oxygen saturation, high total ammonia concentrations, and spikes in the cyanotoxin microcystin. Poor water quality within the lake is considered the most likely cause of juvenile sucker mortality, but mechanisms causing the high mortality are not known. We introduced PIT-tagged age-1 Lost River suckers into three continuously monitored mesocosms in Upper Klamath Lake to determine the timing of juvenile sucker mortality relative to pH, temperature, and dissolved oxygen. Mortality was inferred from a lack of movement detected on remote PIT tag detection equipment within each mesocosm. Mortality was compared among mesocosms and an indoor tank-held control group. We fitted time-varying Cox hazard models to test hypotheses about short-term and chronic effects of single

show abstract

mentioning

confidence: 99%

Mortality of Endangered Juvenile Lost River Suckers Associated with Cyanobacteria Blooms in Mesocosms in Upper Klamath Lake, Oregon

et al. 2020

View full text Add to dashboard Cite

show abstract

“…Their presence could contribute to increasing the nutritional value of the main ingredients, commonly consisting of other food sources, in particular macroalgae, that are part of the sea urchin's normal diet. Even if the possibility of toxin contamination (mainly Microcystins) in Klamath has been reported by other authors [65,66], in the present investigation, we excluded such effect as we used a product intended for human consumption, where the occurrence of Microcystins was estimated at ≤1 ppm, which is lower than the recommended limit [67].…”

Section: Discussionmentioning

confidence: 80%

Blue-Green Algae as Stimulating and Attractive Feeding Substrates for a Mediterranean Commercial Sea Urchin Species, Paracentrotus lividus

Solari

Sollai

Pasquini

et al. 2023

Life

View full text Add to dashboard Cite

Sea urchins rely on chemical senses to localize suitable food resources, therefore representing model species for chemosensory studies. In the present study, we investigated the chemical sensitivity of the Mediterranean sea urchin Paracentrotus lividus to the blue-green alga Aphanizomenon flos-aquae, namely “Klamath”, and to a few amino acids chosen from the biochemical composition of the same algae. To this end, we used the “urchinogram” method, which estimates the movement rate of the sea urchins in response to chemicals. Our results showed that Klamath represents a strong chemical stimulus for P. lividus as it elicits an overall movement of spines, pedicellariae, and tube feet coupled, in some cases, to a coordinated locomotion of the animals. Sea urchins also displayed a sensitivity, even if to a lesser extent, to leucine, threonine, arginine, and proline, thus implying that the amino acids contained in Klamath may account, at least in part, for the stimulating effects exerted by the whole algae. Additionally, our results show that Klamath, as well as spirulina, another blue-green alga with high nutritional value, is very attractive for this sea urchin species. These findings gain further importance considering the potential profit of echinoderms for commercial consumers and their growing role in aquaculture. Klamath and spirulina combine high nutritional profiles with attractive and stimulating abilities and may be considered potential valuable feed supplements in sea urchin aquaculture.

show abstract

“…Regarding P, although there have been some studies on the effect of P availability on the MC production, no conclusive results were found so far. Eldridge et al [32] reported significant correlations between MC concentrations with total phosphorus (TP) and dissolved inorganic phosphorus (DIP) concentrations in sediment. A steady increase of mcyD transcripts was detected in deficiency of P with no significant changes under excess phosphate [13].…”

Section: Discussionmentioning

confidence: 99%

Transcriptional and Physiological Responses to Nutrient Loading on Toxin Formation and Photosynthesis in Microcystis Aeruginosa FACHB-905

Peng

Lin

Fan

et al. 2017

Toxins

View full text Add to dashboard Cite

An important goal of understanding harmful algae blooms is to determine how environmental factors affect the growth and toxin formation of toxin-producing species. In this study, we investigated the transcriptional responses of toxin formation gene (mcyB) and key photosynthesis genes (psaB, psbD and rbcL) of Microcystis aeruginosa FACHB-905 in different nutrient loading conditions using real-time reverse transcription quantitative polymerase chain reaction (RT-qPCR). Three physio-biochemical parameters (malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione (GSH)) were also evaluated to provide insight into the physiological responses of Microcystis cells. We observed an upregulation of mcyB gene in nutrient-deficient conditions, especially in nitrogen (N) limitation condition, and the transcript abundance declined after the nutrient were resupplied. Differently, high transcription levels were seen in phosphorus (P) deficient treatments for key photosynthesis genes throughout the culture period, while those in N-deficient cells varied with time, suggesting an adaptive regulation of Microsystis cells to nutrient stress. Increased contents of antioxidant enzymes (SOD and GSH) were seen in both N and P-deficient conditions, suggesting the presence of excess amount of free radical generation caused by nutrient stress. The amount of SOD and GSH continued to increase even after the nutrient was reintroduced and a strong correlation was seen between the MDA and enzyme activities, indicating the robust effort of rebalancing the redox system in Microcystis cells. Based on these transcriptional and physiological responses of M. aeruginosa to nutrient loading, these results could provide more insight into Microcystis blooms management and toxin formation regulation.

show abstract

Microcystins, nutrient dynamics, and other environmental factors during blooms of non-microcystin-producingAphanizomenon flos-aquaein Upper Klamath Lake, Oregon, 2009

Cited by 17 publications

References 31 publications

Mortality of Endangered Juvenile Lost River Suckers Associated with Cyanobacteria Blooms in Mesocosms in Upper Klamath Lake, Oregon

Mortality of Endangered Juvenile Lost River Suckers Associated with Cyanobacteria Blooms in Mesocosms in Upper Klamath Lake, Oregon

Blue-Green Algae as Stimulating and Attractive Feeding Substrates for a Mediterranean Commercial Sea Urchin Species, Paracentrotus lividus

Transcriptional and Physiological Responses to Nutrient Loading on Toxin Formation and Photosynthesis in Microcystis Aeruginosa FACHB-905

Contact Info

Product

Resources

About