Measurement of Cyanobacterial Bloom Magnitude using Satellite Remote Sensing

Scientific Reports, Journal Year: 2019, Volume and Issue: 9(1)

Published: Dec. 4, 2019

Abstract Cyanobacterial harmful algal blooms (cyanoHABs) are a serious environmental, water quality and public health issue worldwide because of their ability to form dense biomass produce toxins. Models algorithms have been developed detect quantify cyanoHABs using remotely sensed data but not for quantifying bloom magnitude, information that would guide management decisions. We propose method seasonal annual cyanoHAB magnitude in lakes reservoirs. The is the spatiotemporal mean weekly or biweekly maximum cyanobacteria season year. CyanoHAB quantified standard reflectance spectral shape-based algorithm uses from Medium Resolution Imaging Spectrometer (MERIS). demonstrate Florida Ohio (USA) respectively during 2003–2011 rank based on median over study period. new can be applied Sentinel-3 Ocean Land Color Imager (OLCI) assessment change time, even with issues such as variable acquisition frequency sensor calibration uncertainties between satellites. support monitoring decision-making recreational drinking sources.

Language: Английский

---

Response of cyanobacteria and phytoplankton abundance to warming, extreme rainfall events and nutrient enrichment

Global Change Biology, Journal Year: 2019, Volume and Issue: 25(10), P. 3365 - 3380

Published: May 16, 2019

Cyanobacterial blooms are an increasing threat to water quality and global security caused by the nutrient enrichment of freshwaters. There is also a broad consensus that with warming, but impacts other concomitant environmental changes, such as increase in extreme rainfall events, may affect this response. One potential effects high events on phytoplankton communities greater loss biomass through hydraulic flushing. Here we used shallow lake mesocosm experiment test combined of: warming (ambient vs. +4°C increase), (flushing) (no seasonal events) loading (eutrophic hypertrophic) total chlorophyll-a cyanobacterial abundance composition. Our hypotheses were that: (a) would be higher heated mesocosms; (b) stimulatory enhanced mesocosms, resulting synergistic interaction; (c) recovery from flushing induced losses quicker nutrient-enriched treatments, during growing season. The results supported first and, part, third hypotheses: increased mesocosms common bloom-forming taxa-Microcystis spp. Dolichospermum Recovery was slowest winter, unaffected or loading. Contrary second hypothesis, antagonistic interaction between detected for both cyanobacteria demonstrating ecological surprises can occur, dependent context. While study highlights clear need mitigate against oversimplification change should avoided; stressor gradients considered important factors shaping

Language: Английский

---

Under the radar: long-term perspectives on ecological changes in lakes

Proceedings of the Royal Society B Biological Sciences, Journal Year: 2019, Volume and Issue: 286(1906), P. 20190834 - 20190834

Published: July 10, 2019

Aquatic ecosystems are constantly changing due to natural and anthropogenic stressors. When dealing with such ‘moving targets’, one of the greatest challenges faced by scientists, managers policy makers is use appropriate time scales for environmental assessments. However, most aquatic systems lack monitoring data, if a programme does exist, rarely have data been collected more than few years. Hence, it often difficult or impossible determine nature timing ecosystem changes based on these short-term datasets. Furthermore, as assessments typically performed after problem identified, critical regarding pre-disturbance (or reference) conditions available. Here, I summarize some recent studies employing lake sediment analyses (i.e. palaeolimnology) that provided retrospective emerging slowly innocuously ‘under radar’. My examples include identification legacy effects acid rain logging, namely long-term declines in calcium concentrations softwater lakes, which led significant repercussions services. then show past trajectories aerial pollution from burgeoning oil sands operations western Canada can be tracked using proxies preserved dated cores, how used relative contributions versus industrial sources pollutants. conclude reviewing palaeolimnological linked climate change proliferation harmful blue-green algal (cyanobacterial) blooms, even without addition limiting nutrients. Collectively, effective management, particularly incremental stressors, requires temporal sampling windows not readily available standard monitoring, but supplemented high-resolution analyses.

Language: Английский

---

A Review of Water Quality Responses to Air Temperature and Precipitation Changes 2: Nutrients, Algal Blooms, Sediment, Pathogens

JAWRA Journal of the American Water Resources Association, Journal Year: 2018, Volume and Issue: 55(4), P. 844 - 868

Published: Dec. 20, 2018

Abstract In this paper we review the published, scientific literature addressing response of nutrients, sediment, pathogens, and cyanobacterial blooms to historical potential future changes in air temperature precipitation. The goal is document how different attributes water quality are sensitive these drivers, characterize risk, inform management responses, identify research needs fill gaps our understanding. Results suggest that anticipated present a risk ecosystem degradation many United States locations. Understanding responses is, however, complicated by inherent high spatial temporal variability, interactions with land use management, dependence on uncertain hydrology climate. Effects pollutant loading watershed settings generally correlate projected precipitation runoff. all regions, increased heavy events likely drive more episodic bodies. algal could increase due an expanded seasonal window warm temperatures for increases nutrient loading. Increased also affect survival waterborne pathogens. Responding challenges requires understanding vulnerabilities, strategies reduce risk.

Language: Английский

---

The NSERC Canadian Lake Pulse Network: A national assessment of lake health providing science for water management in a changing climate

The Science of The Total Environment, Journal Year: 2019, Volume and Issue: 695, P. 133668 - 133668

Published: Aug. 4, 2019

The distribution and quality of water resources vary dramatically across Canada, human impacts such as land-use climate changes are exacerbating uncertainties in supply security. At the national level, Canada has no enforceable standards for safe drinking comprehensive water-monitoring program to provide detailed, timely reporting on state resources. To Canada's first assessment lake health, NSERC Canadian Lake Pulse Network was launched 2016 an academic-government research partnership. LakePulse uses traditional approaches limnological monitoring well state-of-the-art methods fields genomics, emerging contaminants, greenhouse gases, invasive pathogens, paleolimnology, spatial modelling, statistical analysis, remote sensing. A coordinated sampling about 680 lakes together with historical archives a geomatics analysis over 80,000 watersheds used examine extent which being altered now future, how this aquatic ecosystem services societal importance. Herein we review network context, objectives methods.

Language: Английский

---