Sara Rivero-Calle

University of Georgia | UGA · Department of Marine Sciences

Here we describe the data obtained by a successful proof-of-concept initiative to launch the first ocean color imager on board a CubeSat satellite and collect research-grade imagery at severalfold higher spatial resolution than any other ocean color satellite mission. The 3U CubeSat, named SeaHawk, flew at a nominal altitude of 585 km. Its ocean co...

The Line Height Absorption (LHA) method uses absorption of light to estimate chlorophyll-a. While most users consider regional variability and apply corrections, the effect of temporal variability is typically not explored. The Northern Gulf of Alaska (NGA) was selected for this study because there was no published regional value and its large swin...

The field of oceanography is transitioning from data-poor to data-rich, thanks in part to increased deployment of in-situ platforms and sensors, such as those that instrument the US-funded Ocean Observatories Initiative (OOI). However, generating science-ready data products from these sensors, particularly those making biogeochemical measurements,...

Measuring net community production (NCP) is a challenging, yet important, aspect of oceanography. Methods based on discrete sample collection often have low spatial and temporal resolution, while expensive instruments are required to obtain continuous NCP measurements at high resolution. To address these issues, Izett and Tortell (2020) created a n...

The thermal inversion (TI) is an interesting feature of the global ocean that plays a significant role in ocean-atmospheric process. This study addressed the spatial variability of the TI in the northern Bay of Bengal (NBoB) associated with mixed layer depth (MLD), isothermal layer depth (ILD), barrier layer thickness (BLT), and water mass formatio...

Highly divergent estimates of benthic cover of sponges have been reported for Caribbean mesophotic reefs (90-100 m) based on quadrat point-intercept data collection using 2 methods: visual surveys conducted in situ by technical divers, and analyses of photographs taken by unmanned underwater vehicles (UUVs). The second method has been criticized fo...

The northern Bay of Bengal (BoB) has been traditionally understudied and under-sampled. Satellite and modeling products could compensate for the scarcity of in situ measurements, but this requires evaluating the accuracy of satellite and modeling products first. We present a comparison of sea surface temperature (SST) and sea surface salinity (SSS)...

The Southern Ocean is a key player in regulating the planet's biogeochemistry, productivity, and climate. Ocean color data from two NASA satellites show statistically significant increases in the concentration of chlorophyll in all sectors of the Southern Ocean, particularly in the Sub-Antarctic Zone and Permanently Open Ocean Zone. The smallest ch...

The most abundant and ubiquitous microbes in the surface ocean use light as an energy source, capturing it via complex chlorophyll-based photosystems or simple retinal-based rhodopsins. Studies in various ocean regimes compared the abundance of these mechanisms, but few investigated their expression. Here we present the first full seasonal study of...

Placement of assembled proteorhodopsin ORFs in the MicRhoDE tree clusters indicates that locally assembled rhodopsins represent much of the PR diversity The number of reads (pooled from all samples) that mapped to the assembled ORFs from metatranscriptomes (MT) and metagenomes (MG) was significant compared to number of pooled reads mapped to the cu...

Nutrients and Chlorophyll-A concentrations, cell and viral counts per ml and heterotrophic production measured in the contrasting sampling locations, San Pedro Channel All Chl-a measurements as well as nutrient measurements in October through April are courtesy of the Caron lab, USC. Values in bold are below the instrument detection limit.

Number of post quality control reads (sequencing depth) per sample in metagenomes and metatranscriptomes See data availability section for raw data accession numbers.

Read recruitment to psaA of cyanobacterial and eukaryotic origin demonstrated that the majority of psaA reads were prokaryotic in both metagenomes and metatranscriptomes (A) relative gene abundance of psaA by domain (B) relative transcript abundance of psaA by domain.

Maximum-likelihood tree of PufM and its homologue PsbA protein sequences used to build the HMM and to recruit short reads with pplacer PufM sequences appear in red and PsbA sequences in black.

Comparison of relative abundance (number of reads recruited over total number of reads per sample) of functional genes using reads recruited by HMM or reciprocal blast (A) in metagenomes and (B) in metatranscriptomes. Note that the Y-axis in B is logarithmic.

Variability of phototrophic mechanisms in metagenomes from the three sampling locations of the San Pedro Channel ( n = 4, shown in Fig. 1) Y-axis denotes the percentage of genomes with the particular phototrophic mechanism normalized to recA gene (see methods). psaA for oxygenic photosynthesis, PR for proteorhodopsin and pufM for aerobic anoxygenic...

Maximum-likelihood tree of PsaA protein sequences used to build the HMM and to recruit short reads with pplacer Bacterial sequences appear in blue, viral in red, eukaryotic in green and assembled ORFs in black.

Gene abundance and RNA/DNA ratio of different phototrophic mechanisms by sample (A) Normalized gene abundance and (B) expression of oxygenic photosynthesis (psaA, green), rhodopsin (PR, dotted blue) and anoxygenic photosynthesis (AAnP, grey).

Remote-sensing reflectance spectra (Rrs) in the week preceding the July 2012 sampling shows recovery from an algal bloom which could explain the discrepancy in PR tuning between July and October

Shannon index of evenness of rhodopsin clusters across samples Evenness in metagenomes is denoted by black bars, and in metatranscriptomes by striped bars.

The most abundant and ubiquitous microbes in the surface ocean use light as an energy source, capturing it via complex chlorophyll-based photosystems or simple retinal-based rhodopsins. Studies in various ocean regimes compared the abundance of these mechanisms, but few investigated their expression. Here we present the first full seasonal study of...

The cyanobacterium Trichodesmium fixes as much as half of the nitrogen (N2) that supports tropical open-ocean biomes, but its growth is frequently limited by iron (Fe) availability1,2. How future ocean warming may interact with this globally widespread Fe limitation of Trichodesmium N2 fixation is unclear³. Here, we show that the optimum growth tem...

The most abundant and ubiquitous microbes in the surface ocean use light as an energy source, capturing it via complex chlorophyll-based photosystems or simple retinal-based rhodopsins. Studies in various ocean regimes compared the abundance of these mechanisms, but few investigated their expression. Here we present the first full seasonal study of...

The most abundant and ubiquitous microbes in the surface ocean use light as an energy source, capturing it via complex chlorophyll-based photosystems or simple retinal-based rhodopsins. Studies in various ocean regimes compared the abundance of these mechanisms, but few investigated their expression. Here we present the first full seasonal study of...

Studies of the nitrogen cycle in the ocean generally assume that the distribution of the marine diazotroph, Trichodesmium, is restricted to warm, tropical and sub-tropical oligotrophic waters. Here we show evidence that Trichodesmium are widely distributed in the North Atlantic. We report an approximately five-fold increase during the 1980s and 199...

Passing an acid test Calcifying marine organisms will generally find it harder to make and maintain their carbonate skeletons as increasing concentrations of atmospheric CO 2 acidify the oceans. Nevertheless, some types of organisms will be damaged more than others, and some may even benefit from higher CO 2 levels. Coccolithophores are a case in p...

Although remote sensing technology is a useful tool for monitoring shallow (

The quantitative characterization of the submerged biotopes of Enrique Reef, southwestern Puerto Rico, requires atmospheric and water column corrections of satellite data before performing classification algorithms. The Lyzenga (1978) method was used for deriving three depth-invariant bands based on the visible bands of IKONOS imagery. The spectral...