(Press-News.org)
Phytoplankton determine how much life the ocean is able to support and play a role in controlling atmospheric carbon dioxide concentrations, thereby regulating our climate. These tiny marine plants depend on sunlight as well as nutrients to thrive – including elements such as iron or nitrogen that can be brought to the ocean surface by currents and upwelling.
To understand phytoplankton nutrient limitations in the ocean, scientists typically conduct experiments during research expeditions at sea. However, this approach documents only a tiny fraction of the ocean at a certain point in time. Therefore, an international team of researchers tested if a signal detected by satellites in space can be used to observe nutrient limitation – covering the whole ocean within a few days. For this purpose, they investigated whether fluorescence signals from phytoplankton in the Equatorial Pacific recorded by satellites provided information about phytoplankton nutrient limitation. Observations were made on the expedition SO267/2 with the German research vessel SONNE in 2019. In this ocean region, nutrient availability and phytoplankton productivity varies naturally due to the impacts of the El Niño Southern Oscillation (ENSO). The findings are published today in the scientific journal Nature.
“Although satellites have been making fluorescence measurements for two decades, we do not know yet how to properly interpret them”, says Dr. Thomas Browning. The marine biologist and chemist at GEOMAR Helmholtz Centre for Ocean Research Kiel (Germany) is coordinating author of the Nature publication and group leader of “Ocean Glow”. Supported by the European Research Foundation (ERC), this project aims to develop new approaches to identify which nutrients are limiting phytoplankton growth from satellite observations.
During the 2019 SONNE expedition, the researchers used experiments and analyses of phytoplankton proteins to figure out which nutrients limited phytoplankton growth. They also evaluated variations in phytoplankton fluorescence – red light emitted from phytoplankton that is thought to be regulated by the nutrients that limit phytoplankton growth. Specifically, under iron limitation phytoplankton produce pigment-protein complexes that are highly fluorescent, whereas under nitrogen limitation they do not. Importantly, they also made the same type of optical measurements made by the NASA MODIS satellites, by using instruments fitted to the front of the ship looking down at the sea surface. This field data was then compared to satellite data to assess historical trends in nutrient limitation in the Equatorial Pacific since the start of these satellite observations two decades ago.
“We found that phytoplankton were either limited by either iron or by nitrogen, which led to really distinct properties in phytoplankton fluorescence as detected by satellites. We also found that the intensity of iron limitation also influenced fluorescence signals: More intense iron limitation resulted in more fluorescence”, summarises Dr. Browning. Fluorescence observations from the satellites varied in a way that matched the supply of iron upwelled from deeper waters over ENSO cycles.
When they compared their observations to predictions made by a global biogeochemical model, the researchers found a striking difference: Changes in iron limitation were coherent with ENSO dynamics over multiple cycles. But the model overestimated the impact on phytoplankton iron limitation twofold compared to field observations. In this way, these types of synoptic observations of nutrient limitation from satellites may be key to validating and improving such models – and to better predict the impacts of future climate change on ocean ecosystems.
“These first findings demonstrate how satellite observations can help us assess the impact of nutrient limitations on phytoplankton and their important role in the global ocean and our climate system”, emphasises Dr. Browning. “However, our study was focussed on the Equatorial Pacific. With the new ERC project ‘Ocean Glow’, we plan to validate this much more robustly for all regions of the ocean.”
Original publication:
Browning, T.J., Saito, M.A., Garaba, S.P, Wang, X., Achterberg, E.P., Moore, M., Engel, A., Mcllvin, M.R., Moran, D., Voss, D., Zielinski, O., Tagliabue, A. (2023): Persistent equatorial Pacific iron limitation under ENSO forcing. Nature, doi: https://doi.org/10.1038/s41586-023-06439-0
Project funding:
This research was largely funded by the projects “Eq-Pac co-limitation” and “OceanLight” supported by the German Ministry for Education and Research (Bundesministerium für Bildung und Forschung, BMBF).
Background: Ocean Glow
The recently started project “Ocean Glow” aims to investigate the potential for observing ocean nutrient limitation globally using satellite-detected phytoplankton fluorescence signals. It is led by Dr. Thomas Browning marine biologist and chemist at GEOMAR Helmholtz Centre for Ocean Research Kiel (Germany) and supported by a Starting Grant from the European Research Council (ERC) of 1.5 million Euros.
END
Medications to treat various chronic diseases may hinder the body’s ability to lose heat and regulate its core temperature to optimal levels. The loss of effective thermoregulation has implications for elderly people receiving treatment for illnesses like cancer, cardiovascular, Parkinson’s disease/dementia and diabetes, particularly during hot weather, according to a review by a team of scientists from various institutions in Singapore.
The group, led by Associate Professor Jason Lee from the Human Potential Translational Research Programme at the Yong Loo Lin School of ...
Leaf-tailed geckos are masters of camouflage. Some species have skin flaps around the whole body and head, as well as flattened tails. During the day, they rest head-down on tree trunks with these skin flaps spread out, and blend seamlessly into their surroundings, making them nearly impossible to spot. At night, they awaken to prowl the fine branches of the understory looking for invertebrate prey.
“When we first discovered this species in 2000, we already suspected it might be new to science,” says Dr Frank Glaw, curator of herpetology at the Bavarian State Collection of Zoology, lead author on the study. “But ...
HOUSTON ― The University of Texas MD Anderson Cancer Center’s Research Highlights showcases the latest breakthroughs in cancer care, research and prevention. These advances are made possible through seamless collaboration between MD Anderson’s world-leading clinicians and scientists, bringing discoveries from the lab to the clinic and back.
Recent developments include a novel single-cell sequencing technology that allows for rapid analyses of archived and frozen cells, greater understanding of the ...
Researchers have found a way to control the interaction of light and quantum ‘spin’ in organic semiconductors, that works even at room temperature.
Spin is the term for the intrinsic angular momentum of electrons, which is referred to as up or down. Using the up/down spin states of electrons instead of the 0 and 1 in conventional computer logic could transform the way in which computers process information. And sensors based on quantum principles could vastly improve our abilities to measure and study the world around us.
An international team of researchers, led by the University of ...
Francis Crick Institute press release
Under strict embargo: 16:00hrs BST 16 August 2023
Peer reviewed
Experimental study
Animals
Research finds that molecules in vegetables can help to ease lung infection
Researchers at the Francis Crick Institute have found that molecules in vegetables like broccoli or cauliflower help to maintain a healthy barrier in the lung and ease infection.
The AHR – aryl hydrocarbon receptor – is a protein found at barrier sites like the gut and the lung. Natural molecules in cruciferous vegetables – for example, kale, cauliflower, broccoli, or cabbage – are dietary ...
In countries such as Peru, Bolivia and Chile, it’s not uncommon for people who live in foggy areas to hang up nets to catch droplets of water. The same is true of Morocco and Oman. These droplets then trickle down the mesh and are collected to provide water for drinking, cooking and washing. As much as several hundred litres of water can be harvested daily using a fog net only a few square metres in area. For regions with little rain or spring water, but where fog is a common occurrence, this can be a blessing.
One crucial drawback with this method, however, ...
About The Study: Children who experienced assault had, on average, a 2 times higher risk of receiving a mental illness diagnosis and were more likely than children who had not experienced assault to present to acute care for mental illness. Early intervention to support mental health of assaulted children is warranted, particularly in the first year following assault.
Authors: Natasha Ruth Saunders, M.D., M.Sc., of the Hospital for Sick Children in Toronto, is the corresponding author.
To ...
About The Study: In this study of 28,000 middle and high school students, the prevalence of vaping cannabidiol (CBD) was high, particularly among e-cigarette users and Hispanic and sexual minority populations. The findings suggest that evidence-based educational campaigns, interventions, and public policy changes are needed to reduce the harmful health outcomes possible with vaping CBD among developing youths.
Authors: Hongying Daisy Dai, Ph.D., of the University of Nebraska Medical Center in Omaha, is the corresponding author.
To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/
(doi:10.1001/jamanetworkopen.2023.29167)
Editor’s ...
About The Study: The incidence rates in the U.S. of early-onset cancer (younger than age 50) increased from 2010 to 2019 in this study of 562,000 patients. Although breast cancer had the highest number of incident cases, gastrointestinal cancers had the fastest-growing incidence rates among all early-onset cancers. These data may be useful for the development of surveillance strategies and funding priorities.
Authors: Daniel Q. Huang, M.B.B.S., M.M.E.D., and Cheng Han Ng, M.B.B.S., of the National University of Singapore, are the corresponding authors.
To access the embargoed study: ...
In a groundbreaking study published today in Nature, Australian scientists have resolved a long-standing problem in regenerative medicine. Led by Professor Ryan Lister from the Harry Perkins Institute of Medical Research and The University of Western Australia and Professor Jose M Polo from Monash University and the University of Adelaide, the team developed a new method to reprogram human cells to better mimic embryonic stem cells, with significant implications for biomedical and therapeutic uses.
In a revolutionary advance in the mid-2000s, it was ...
