Trevor Platt FRS, FRSC | |
---|---|
Born | August 12, 1942 Salford, UK |
Died | April 6, 2020 Plymouth, UK |
Alma mater | Dalhousie University |
Known for | Mathematical formulation of the relationship between photosynthesis and light for phytoplankton (P-I curve) |
Spouse | Shubha Sathyendranath |
Awards | G. Evelyn Hutchinson Award, A.G. Huntsman Award |
Scientific career | |
Fields | Oceanography |
Institutions | Bedford Institute of Oceanography, Plymouth Marine Laboratory |
Trevor Charles Platt FRS FRSC (August 12, 1942 - April 6, 2020) was a British and Canadian biological oceanographer who was distinguished for his fundamental contributions to quantifying primary production by phytoplankton at various scales of space and time in the ocean. [1]
Platt was born in Salford, England in 1942 and received his BSc at the University of Nottingham, UK. He received his MA in 1965 from the University of Toronto, Canada for his thesis “Computer analysis of beam handling system for a linear accelerator”. Later in the same year, Platt started work at the Bedford Institute of Oceanography in Dartmouth, Nova Scotia. [2] With the benefit of field and laboratory work conducted by his technical assistant Brian Irwin, [3] who joined the institute in 1966, [4] Platt embarked on studies that led to the fulfillment in 1970 of his PhD thesis (“Some effects of spatial and temporal heterogeneity on phytoplankton productivity”) [5] at Dalhousie University.
Platt's early research [6] was framed by the overarching goals originally envisioned by the founders of the Atlantic Oceanographic Group of the Fisheries Research Board of Canada at the Bedford Institute of Oceanography, namely: “to describe pathways and to measure amounts and rates of energy transfer in marine biological communities; and to study the structure and degree of organization of biological systems in the sea”. [2] [7] One such early collaborative work [8] concerning energy flow and species diversity in marine phytoplankton blooms was motivated by the ideas of Ramon Margalef, who evidently was nominated by Platt in a later year to receive one of three inaugural medals of the A.G. Huntsman Award for Excellence in the Marine Sciences.
In the ensuing years, Platt, with collaborators, undertook a research program that progressed from investigations of the spatial inhomogeneity of plankton distribution in response to the power spectrum of turbulence, [9] through the physiological responses of the growth of cells in response to light and nutrients, [10] [11] to dimensional analysis and the size structure of pelagic food chains, [12] [13] further to theoretical considerations of the limits of biological production in the ocean, [14] [15] and eventually to the effects of climate change and variability on the biological cycle in the ocean. [16]
By the late 1980s, Platt's research program at the Bedford Institute of Oceanography [17] had reached a stage where the solid foundations built from a close relationship between theoretical developments and observations at sea provided the ready capabilities to embrace the possibilities offered by satellite remote sensing of the ocean. With his close collaborator Shubha Sathyendranath, Platt successfully implemented the analytical solutions and measurement-driven algorithms at regional and ocean basin scales to compute integrated primary production through the water column. [18] [19] In 1995, the long-sought calculation of annual global production by marine phytoplankton was made possible for the first time, [20] after Alan Longhurst successfully partitioned the global ocean into a set of biogeochemical provinces within which the phytoplankton are likely subject to common physical forcing. [21]
In later years after the estimation of marine primary production at large geographical scale was made operational, [22] Platt increasingly turned his attention to the use of remotely-sensed ocean colour as indicators of ecosystem performance [23] towards the management of fisheries [24] and stewardship of the ocean. [25]
Platt joined the Fisheries Research Board of Canada at the then three year old Bedford Institute of Oceanography in Dartmouth, Nova Scotia on June 22, 1965 as a research scientist in the public service. [2] In 1972, he took over from Kenneth H. Mann as head of the Biological Oceanography Section. He served as head until 2000, after which he remained in the section as senior research scientist. In 2005, he transferred to the Coastal Ocean Science Section, still at the Bedford Institute of Oceanography, and remained there until his departure in 2008. Platt was appointed Professorial Fellow at the Plymouth Marine Laboratory (UK) in 2008, and Jawaharlal Nehru Science Fellow at the Central Marine Fisheries Research Institute (India) in 2014.
Platt served the Association for the Sciences of Limnology and Oceanography (ASLO) for two separate terms as a member-at-large (1974-1977, 1986-1989), then as President (1990-1992).
Platt played an especially important role in the International Ocean Colour Coordinating Group (IOCCG), being one of the founding members of the group, and served as the first Chairman of the IOCCG for a period of 10 years (from 1996-2006).
Platt also had a long association with the Partnership for Observation of the Global Ocean (POGO), first as a visiting Professor in 2005, and then as its Executive Director from 2008 to 2015. [1]
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.
Zooplankton are the animal component of the planktonic community, having to consume other organisms to thrive. Plankton are aquatic organisms that are unable to swim effectively against currents. Consequently, they drift or are carried along by currents in the ocean, or by currents in seas, lakes or rivers.
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 biological pump (or ocean carbon biological pump or marine biological carbon pump) is the ocean's biologically driven sequestration of carbon from the atmosphere and land runoff to the ocean interior and seafloor sediments. In other words, it is a biologically mediated process which results in the sequestering of carbon in the deep ocean away from the atmosphere and the land. The biological pump is the biological component of the "marine carbon pump" which contains both a physical and biological component. It is the part of the broader oceanic carbon cycle responsible for the cycling of organic matter formed mainly by phytoplankton during photosynthesis (soft-tissue pump), as well as the cycling of calcium carbonate (CaCO3) formed into shells by certain organisms such as plankton and mollusks (carbonate pump).
The Bedford Institute of Oceanography (BIO) is a major Government of Canada ocean research facility located in Dartmouth, Nova Scotia. BIO is the largest ocean research station in Canada. Established in 1962 as Canada's first, and currently largest, federal centre for oceanographic research, BIO derives its name from the Bedford Basin, an inland bay comprising the northern part of Halifax Harbour, upon which it is located.
SeaWiFS was a satellite-borne sensor designed to collect global ocean biological data. Active from September 1997 to December 2010, its primary mission was to quantify chlorophyll produced by marine phytoplankton.
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.
Colored dissolved organic matter (CDOM) is the optically measurable component of dissolved organic matter in water. Also known as chromophoric dissolved organic matter, yellow substance, and gelbstoff, CDOM occurs naturally in aquatic environments and is a complex mixture of many hundreds to thousands of individual, unique organic matter molecules, which are primarily leached from decaying detritus and organic matter. CDOM most strongly absorbs short wavelength light ranging from blue to ultraviolet, whereas pure water absorbs longer wavelength red light. Therefore, water with little or no CDOM, such as the open ocean, appears blue. Waters containing high amounts of CDOM can range from brown, as in many rivers, to yellow and yellow-brown in coastal waters. In general, CDOM concentrations are much higher in fresh waters and estuaries than in the open ocean, though concentrations are highly variable, as is the estimated contribution of CDOM to the total dissolved organic matter pool.
Ocean color is the branch of ocean optics that specifically studies the color of the water and information that can be gained from looking at variations in color. The color of the ocean, while mainly blue, actually varies from blue to green or even yellow, brown or red in some cases. This field of study developed alongside water remote sensing, so it is focused mainly on how color is measured by instruments.
Paul G. Falkowski is an American biological oceanographer in the Institute of Marine and Coastal Sciences at Rutgers University in New Brunswick, New Jersey. His research work focuses on phytoplankton and primary production, and his wider interests include evolution, paleoecology, photosynthesis, biogeochemical cycles and astrobiology.
Michael John Robert Fasham, FRS was a British oceanographer and ecosystem modeller. He is best known for his pioneering work in the development of open ocean plankton ecosystem models.
The PIcurve is a graphical representation of the empirical relationship between solar irradiance and photosynthesis. A derivation of the Michaelis–Menten curve, it shows the generally positive correlation between light intensity and photosynthetic rate. It is a plot of photosynthetic rate as a function of light intensity (irradiance).
The A.G. Huntsman Award for Excellence in the Marine Sciences was established in 1980 by the Canadian marine science community to recognize excellence of research and outstanding contributions to marine sciences. It is presented by the Royal Society of Canada. The award honours marine scientists of any nationality who have had and continue to have a significant influence on the course of marine scientific thought. It is named in honour of Archibald Gowanlock Huntsman (1883–1973), a pioneer Canadian oceanographer and fishery biologist.
Alan Reece Longhurst was a British-born Canadian oceanographer who invented the Longhurst-Hardy Plankton Recorder, and is widely known for his contributions to the primary scientific literature, together with his numerous monographs, most notably the "Ecological Geography of the Sea". He led an effort that produced the first estimate of global primary production in the oceans using satellite imagery, and also quantified vertical carbon flux through the planktonic ecosystem via the biological pump. In later life he offered several critical reviews of several aspects of fishery management science and climate change science.
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.
William Li is a Canadian biological oceanographer who did research on marine picoplankton, marine macroecology, ocean surveys of plankton from measurements of flow cytometry, and detection of multi-annual ecological change in marine phytoplankton.
Benthic-pelagic coupling are processes that connect the benthic zone and the pelagic zone through the exchange of energy, mass, or nutrients. These processes play a prominent role in both freshwater and marine ecosystems and are influenced by a number of chemical, biological, and physical forces that are crucial to functions from nutrient cycling to energy transfer in food webs.
The Great Calcite Belt (GCB) refers to a region of the ocean where there are high concentrations of calcite, a mineral form of calcium carbonate. The belt extends over a large area of the Southern Ocean surrounding Antarctica. The calcite in the Great Calcite Belt is formed by tiny marine organisms called coccolithophores, which build their shells out of calcium carbonate. When these organisms die, their shells sink to the bottom of the ocean, and over time, they accumulate to form a thick layer of calcite sediment.
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.
Shubha Platt, known professionally as Shubha Sathyendranath, is a marine scientist known for her work on marine optics and remote sensing of ocean colour. She is the 2021 recipient of the A.G. Huntsman Award for Excellence in the Marine Sciences.
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