Sarah Fawcett is a South African oceanographer and climatologist. [1] A senior lecturer in the Department of Oceanography at the University of Cape Town, she is particularly interested in the role of oceans in regulating biogeochemical cycles and how their dysregulation contributes to climate change. [2] [3] She was honoured in the World Economic Forum Young Scientists Class of 2020, [4] and a P-Rating from the National Research Foundation, which recognizes that the scientist's work will likely have high impact. [2]
Fawcett was born in Benoni, Gauteng, and attended Benoni High School. [3] She went on to study Earth and planetary science at Harvard University (2006) and completed a PhD at Princeton (2012) where she later held a postdoctoral fellowship (2012-2015). [5]
In 2015, Fawcett was appointed a lecturer in oceanography at the University of Cape Town. [2] She has worked to build up a diverse research group, aware of the discrimination still faced by female scientists. [2] [3] From 2016, she has participated in the SEAmester scheme that aims to train up postdoctoral oceanography researchers. [2]
In her doctorate Fawcett investigated the relationship between nitrogen and populations of phytoplankton in upwelling ecosystems of the Sargasso Sea. [6] She has continued to work on these relationships, concentrating on the subpolar North Atlantic and Southern Ocean as areas of particular importance. [3] The sequestration of carbon through the biological pump in these regions may be an important regulatory of the global ocean system, but the dynamics of the nitrogen-phytoplankton system limit its efficiency. [6] Much of Fawcett's works is based on measurements of stable nitrogen isotopes. [5] Fawcett is also addressing the lack of research in the Benguela Upwelling System, which is important for the biodiversity and economy of the region. [3] She is also primary investigator for the Antarctic Circumnavigation Expedition (ACE). [7]
In 2017, she received the South African Network for Coastal and Oceanic Research (SANCOR) Young Researchers Award and the Claude Leon Merit Award for Early-Career Researchers. [2] She was also distinguished as one of the Top 200 Young South Africans by the Mail and Guardian and received a NRF P-rating meaning her early career had suggested she would go on to become "a future international leader in [her] field". [2] [5] In 2018, the University of Cape Town awarded her its College of Fellows Young Researcher Award. [8] In 2020, the World Economic Forum added Fawcett to its group of 25 young researchers at the "forefront of scientific discovery" for that year on account of her research on "ocean chemistry and biology in climate" and the "impacts of human activities on marine environments." [4]
Antarctic Circumpolar Current (ACC) is an ocean current that flows clockwise from west to east around Antarctica. An alternative name for the ACC is the West Wind Drift. The ACC is the dominant circulation feature of the Southern Ocean and has a mean transport estimated at 100–150 Sverdrups, or possibly even higher, making it the largest ocean current. The current is circumpolar due to the lack of any landmass connecting with Antarctica and this keeps warm ocean waters away from Antarctica, enabling that continent to maintain its huge ice sheet.
The photic zone, euphotic zone, epipelagic zone, or sunlight zone is the uppermost layer of a body of water that receives sunlight, allowing phytoplankton to perform photosynthesis. It undergoes a series of physical, chemical, and biological processes that supply nutrients into the upper water column. The photic zone is home to the majority of aquatic life due to the activity of the phytoplankton. The thicknesses of the photic and euphotic zones vary with the intensity of sunlight as a function of season and latitude and with the degree of water turbidity. The bottommost, or aphotic, zone is the region of perpetual darkness that lies beneath the photic zone and includes most of the ocean waters.
An algal bloom or algae bloom is a rapid increase or accumulation in the population of algae in freshwater or marine water systems. It is often recognized by the discoloration in the water from the algae's pigments. The term algae encompasses many types of aquatic photosynthetic organisms, both macroscopic multicellular organisms like seaweed and microscopic unicellular organisms like cyanobacteria. Algal bloom commonly refers to the rapid growth of microscopic unicellular algae, not macroscopic algae. An example of a macroscopic algal bloom is a kelp forest.
Upwelling is an oceanographic phenomenon that involves wind-driven motion of dense, cooler, and usually nutrient-rich water from deep water towards the ocean surface. It replaces the warmer and usually nutrient-depleted surface water. The nutrient-rich upwelled water stimulates the growth and reproduction of primary producers such as phytoplankton. The biomass of phytoplankton and the presence of cool water in those regions allow upwelling zones to be identified by cool sea surface temperatures (SST) and high concentrations of chlorophyll a.
The Benguela Current is the broad, northward flowing ocean current that forms the eastern portion of the South Atlantic Ocean gyre. The current extends from roughly Cape Point in the south, to the position of the Angola-Benguela front in the north, at around 16°S. The current is driven by the prevailing south easterly trade winds. Inshore of the Benguela Current proper, the south easterly winds drive coastal upwelling, forming the Benguela Upwelling System. The cold, nutrient rich waters that upwell from around 200–300 m (656–984 ft) depth in turn fuel high rates of phytoplankton growth, and sustain the productive Benguela ecosystem.
The Canary Current is a wind-driven surface current that is part of the North Atlantic Gyre. This eastern boundary current branches south from the North Atlantic Current and flows southwest about as far as Senegal where it turns west and later joins the Atlantic North Equatorial Current. The current is named after the Canary Islands. The archipelago partially blocks the flow of the Canary Current.
High-nutrient, low-chlorophyll (HNLC) regions are regions of the ocean where the abundance of phytoplankton is low and fairly constant despite the availability of macronutrients. Phytoplankton rely on a suite of nutrients for cellular function. Macronutrients are generally available in higher quantities in surface ocean waters, and are the typical components of common garden fertilizers. Micronutrients are generally available in lower quantities and include trace metals. Macronutrients are typically available in millimolar concentrations, while micronutrients are generally available in micro- to nanomolar concentrations. In general, nitrogen tends to be a limiting ocean nutrient, but in HNLC regions it is never significantly depleted. Instead, these regions tend to be limited by low concentrations of metabolizable iron. Iron is a critical phytoplankton micronutrient necessary for enzyme catalysis and electron transport.
Ocean fertilization or ocean nourishment is a type of technology for carbon dioxide removal from the ocean based on the purposeful introduction of plant nutrients to the upper ocean to increase marine food production and to remove carbon dioxide from the atmosphere. Ocean nutrient fertilization, for example iron fertilization, could stimulate photosynthesis in phytoplankton. The phytoplankton would convert the ocean's dissolved carbon dioxide into carbohydrate, some of which would sink into the deeper ocean before oxidizing. More than a dozen open-sea experiments confirmed that adding iron to the ocean increases photosynthesis in phytoplankton by up to 30 times.
Sallie Watson "Penny" Chisholm is an American biological oceanographer at the Massachusetts Institute of Technology. She is an expert in the ecology and evolution of ocean microbes. Her research focuses particularly on the most abundant marine phytoplankton, Prochlorococcus, that she discovered in the 1980s with Rob Olson and other collaborators. She has a TED talk about their discovery and importance called "The tiny creature that secretly powers the planet".
The Malaspina circumnavigation expedition was an interdisciplinary research project to assess the impact of global change on the oceans and explore their biodiversity. The 250 scientists on board the Hespérides and Sarmiento de Gamboa embarked on an eight-month expedition scientific research with training for young researchers - advancing marine science and fostering the public understanding of science.
Nils Daniel Bang was a South African oceanographic scientist who was a pioneer in the study of the fine structure of coastal upwelling systems. In March 1969, Bang initiated, planned and executed South Africa's first truly multi-ship oceanographical research operation, the Agulhas Current Project, along the current's length. Although the research was conducted on a limited budget and with rudimentary equipment, Bang's studies using thousands of closely spaced bathythermograph readings were later corroborated by satellite imagery and airborne radiation thermometry.
Johann Reinder Erlers Lutjeharms, was a leading South African marine scientist and an authority in the oceanography of the Agulhas Current, who authored a definitive work on the subject, The Agulhas Current. His main field of investigation was the large-scale circulation patterns of the oceans adjacent to southern Africa and their influence on weather and climate, and he participated in 17 research cruises and was responsible for a further 48 projects undertaken on such cruises.
Susana Agustí Requena is a Spanish biological oceanographer who has participated in over 25 oceanographic expeditions in the Arctic, Southern Ocean (Antarctic), Atlantic, Pacific and Indian Oceans. She played a key role in the Malaspina Circumnavigation Expedition. She is professor in Marine Science at King Abdullah University of Science and Technology in Saudi Arabia and an adjunct Professor at the University of Tromsø (Norway).
The viral shunt is a mechanism that prevents marine microbial particulate organic matter (POM) from migrating up trophic levels by recycling them into dissolved organic matter (DOM), which can be readily taken up by microorganisms. The DOM recycled by the viral shunt pathway is comparable to the amount generated by the other main sources of marine DOM.
The Marine biodiversity of South Africa is the variety of living organisms that live in the seas off the coast of South Africa. It includes genetic, species and ecosystems biodiversity in a range of habitats spread over a range of ecologically varied regions, influenced by the geomorphology of the seabed and circulation of major and local water masses, which distribute both living organisms and nutrients in complex and time-variable patterns.
Bess Ward is an American oceanographer, biogeochemist, microbiologist, and William J. Sinclair Professor of Geosciences at Princeton University.
Patricia A. Wheeler is a retired American phycologist and oceanographer. She is known for her work physiology and ecology of marine phytoplankton and primary production in marine ecosystems.
Clarice Morel Yentsch is a scientist, author, education and museum professional, and community benefactor. As a scientist, she pioneered the use of flow cytometry to investigate marine phytoplankton and co-founded Bigelow Laboratory for Ocean Sciences.
Low-nutrient, low-chlorophyll (LNLC)regions are aquatic zones that are low in nutrients and consequently have low rate of primary production, as indicated by low chlorophyll concentrations. These regions can be described as oligotrophic, and about 75% of the world's oceans encompass LNLC regions. A majority of LNLC regions are associated with subtropical gyres but are also present in areas of the Mediterranean Sea, and some inland lakes. Physical processes limit nutrient availability in LNLC regions, which favors nutrient recycling in the photic zone and selects for smaller phytoplankton species. LNLC regions are generally not found near coasts, owing to the fact that coastal areas receive more nutrients from terrestrial sources and upwelling. In marine systems, seasonal and decadal variability of primary productivity in LNLC regions is driven in part by large-scale climatic regimes leading to important effects on the global carbon cycle and the oceanic carbon cycle.
Edem Mahu is a Ghanaian marine scientist who is a senior lecturer at the University of Ghana. Her research considers ocean health, oyster fisheries and climate change. She was awarded the 2022 American Geophysical Union Africa Award for Research Excellence in Ocean Sciences.