Steve Ruberg's research while affiliated with NOAA Fisheries and other places

Publications (12)

Article
Full-text available
Retrieval of the phycocyanin concentration (PC), a characteristic pigment of, and proxy for, cyanobacteria biomass, from hyperspectral satellite remote sensing measurements is challenging due to uncertainties in the remote sensing reflectance (∆R rs) resulting from atmospheric correction and instrument radiometric noise. Although several individual...
Article
Full-text available
Lake Erie’s central basin experiences seasonal anoxia, contributing to internal sediment phosphorus (P) loading and exacerbating eutrophication. The precise conditions required for internal loading are poorly understood. This study constrains the timing and rates of internal P loading using continuous in situ temperature, dissolved oxygen (DO), and...
Article
Full-text available
Retrieval of aquatic biogeochemical variables, such as the near-surface concentration of chlorophyll-a (Chla) in inland and coastal waters via remote observations, has long been regarded as a challenging task. This manuscript applies Mixture Density Networks (MDN) that use the visible spectral bands available by the Operational Land Imager (OLI) ab...
Article
Despite the initial success of extensive efforts to reduce phosphorus (P) loading to Lake Erie as part of the Great Lakes Water Quality Agreement, Lake Erie appears to be undergoing a re-eutrophication and is plagued by harmful algal blooms. To offer insights into potential lake responses under differing Maumee River loads and reveal recent changes...
Article
Full-text available
Harmful algal blooms (HABs) produce local impacts in nearly all freshwater and marine systems. They are a problem that occurs globally requiring an integrated and coordinated scientific understanding, leading to regional responses and solutions. Given that these natural phenomena will never be completely eliminated, an improved scientific understan...
Article
Full-text available
Harmful algal blooms have become a more significant issue in recent years in many lakes and rivers, and it is a particularly significant issue in the western basin of Lake Erie. In response, several research organizations in the United States and Canada have increased their efforts to improve capabilities for the remote sensing of harmful algal blo...
Article
Full-text available
NOAA GLERL has routinely flown a hyperspectral imager to detect cyanobacteria harmful algal blooms (cyanoHABs) over the Great Lakes since 2015. Three consecutive years of hyperspectral imagery over the Great Lakes warn drinking water intake managers of the presence of cyanoHABs. Western basin imagery of Lake Erie contributes to a weekly report to t...
Article
Full-text available
There is a growing use of remote sensing observations for detecting and quantifying freshwater cyanobacteria populations, yet the inherent optical properties of these communities in natural settings, fundamental to bio-optical algorithms, are not well known. Toward bridging this knowledge gap, we measured a full complement of optical properties in...
Technical Report
Full-text available
This report provides a research plan and action strategy for addressing the causes and impacts of harmful algal blooms (HABs) and hypoxia on stakeholders of all types within the Great Lakes region. Over the past several decades, HABs and hypoxia (low-oxygen conditions) have caught the nation’s attention due to the associated negative socioeconomic,...
Technical Report
Full-text available
The report outlines Federal agencies’ roles and responsibilities for evaluating and managing HABs and hypoxia, agency successes since the 2008 authorization of HABHRCA, and their management and response actions. It also identifies remaining challenges and makes recommendations for actions to address these events. It draws from direct contributions...

Citations

... For example, Kudela et al. (2015b) used airborne (HyspIRI airborne campaign) and satellite (Hyperspectral Imager for the Coastal Ocean or HICO) hyperspectral images to differentiate between Aphanizomenon and Microcystis in Pinto Lake, CA (Kudela et al., 2015b). O'Shea et al. (2021) also demonstrated that phycocyanin concentrations, and hence cyanobacteria biomass, could be retrieved from HICO data using a class of neural network models known as mixture density networks. ...
... More precisely, we presume this timelag was caused by the slow reduction of Fe(III) to Fe(II), given our observation of a change in color from red to gray at the sediment surface. This is consistent with recent observations from Lake Erie, where PO 4 3 − release was not observed under hypoxic conditions, but instead was observed between 12 and 24 h following the onset of anoxic conditions ( Anderson et al., 2021 ). Due to this suppression of PO 4 3 − fluxes at the start of the anoxic trials, PO 4 3 − fluxes were only calculated after this 20-hour time window had passed, once the PO 4 3 − concentration started increasing. ...
... Numerous approaches for estimating chlorophyll concentrations in freshwater have been established, including semi-empirical indices and other metrics of spectral shape that compare reflectance values between bands (Ekstrand, 1992;Hellweger et al., 2004;Sass et al., 2007;Liu et al., 2010;Khan et al., 2021). More recently, machine learning approaches have been developed for this purpose (Doerffer and Schiller, 2007;Kajiyama et al., 2019;Pahlevan et al., 2020;Smith et al., 2021). ...
... Because the Great Lakes have minimal amounts of salt (specific conductance ranges from $ 95 to 350 mS/cm, (Chapra et al., 2012; see also ESM Table S1), a salinity of zero was assumed. Total silica and total phosphorus concentrations were also assumed to be zero as they are 1.5 to three magnitudes lower in concentration (by mass) than open-lake alkalinity values (e.g., (Barbiero et al., 2012;Chapra et al., 2012;Lin and Guo, 2016a;Rowland et al., 2020). ...
... • In future, short-term advective forecasts might be improved by adding a biological model or machine learning component to improve the prediction during the onset of blooms. Another direction for which these advective models might be important is the cross boundary, to alert between different currently discrete regional modelling systems (Maguire et al., 2016;Anderson et al., 2019). Nevertheless our results have shown that the choices underlying the hydrodynamic model setup also have a significant effect on the results and improvements to the understanding and implementation of these models is as important as adding extra features. ...
... The portability of satellite-derived algorithms as applied to imagery with higher spectral (hyperspectral), spatial, and temporal resolutions is not well understood particularly with respect to assessing the life cycle characteristics of cyanobacteria bloom events. For example, hyperspectral sensors have greater utility for detecting and quantifying HAB indicators as they have hundreds of narrow spectral bands which allows for the identification of spectral features characteristic of HABs: green reflectance (550 nm), phycocyanin absorption (620 nm), chlorophyll a absorption (665 nm -680 nm), and cell backscattering or turbidity (709 nm) (Davis and Bissett, 2007;Lekki et al., 2019;Shen et al., 2012;Stumpf et al., 2016). ...
... It can collect data at a high spatial resolution of 1 m, with the advantage of on-demand airborne flight paths not affected by cloud cover [19]. The HSI2 camera images have been used for assessing spatial and temporal variability of blue-green algae, chlorophyll, and temperature [20]. The airborne imagery serves as a complement to satellite-based measurements. ...
... Additionally, a highthroughput microscopy denoted as environmental high content fluorescence microscopy (e-HCFM), has recently been described for generating 3D multi-channel images of nanoplankton (5-20 µm) and microplankton (20-180 µm) from preserved samples (Figure 1B). These instruments deliver highly diverse and continuous image datasets from planktonic populations, and some can be deployed for in situ monitoring (e.g., for harmful algal blooms; Moore et al., 2017;Moore et al., 2019;Henrichs et al., 2021) and/or for in situ quantification of fragile organisms that are difficult to collect by nets (Hull et al., 2011;Biard et al., 2016;Gaskell et al., 2019). It is expected that the volume and complexity of marine data will increase by orders of magnitude in the coming years and the annotation rate of human experts is currently lagging behind the data generated. ...
... Much measures including drainage water management and subsurface fertilizer application were applied to reduce the inputs of nitrogen and phosphorus pollutants from terrestrial sources in order to reverse the eutrophication of lakes [48,53]. However, the eutrophication state of these shallow lakes has not been really alleviated [52,56,57]. With the further research of eutrophication issue, sediment internal phosphorus has been concerned and was thought to be a major driver of harmful algal blooms due to the fact that the path of phosphorus translation fewer and simpler compared with that of nitrogen [34,36]. ...
... Zamyadi et al. [7] study to control and reduce the effects of algae bloom on freshwater ecosystems are essential for ensuring the safety of drinking water supplies monitoring the frequency and the physiological state of the bloom is vital to develop efficient for managing water resource. In a wide region, the detection of algae blooms can be possible through monitoring by aerial aircraft using hyper-spectral or multispectral images taken from drones, aircraft or satellites has been proven to be a successful method [8][9][10]. Whereas constant and direct monitoring is necessary for quick and efficient operational responses within water management districts and services for processing drinking water to prevent unintentional algae bloom. ...