Secchi disks are lowered into the water to measure phytoplankton abundance. Credit score: AMT
A easy 19th Century device continues to be helpful to ocean scientists within the age of satellites, new analysis revealed in Frontiers in Marine Science reveals.
A Secchi disk – traditionally referred to as a “dinner plate” by sailors – is used within the open ocean to measure concentrations of microscopic algae referred to as phytoplankton.
It really works by reducing the white disk into the water and recording the depth at which it disappears.
Within the new research, a analysis staff together with the College of Exeter, Plymouth Marine Laboratory, Vrije Universiteit (Netherlands) and the Italian Institute of Marine Sciences (ISMAR) in contrast the efficiency of Secchi disks with satellites and high-performance chromatography.
Secchi disks carried out nearly in addition to fashionable strategies at monitoring phytoplankton abundance – that means Secchi measurements going again greater than a century can assist scientists perceive long-term modifications within the ocean.
“Phytoplankton produce half the world’s oxygen and type the bottom of ocean meals webs, so monitoring them helps us observe every part from local weather change to the well being of ecosystems,” stated Dr. Bob Brewin, from the Centre for Geography and Environmental Science on Exeter’s Penryn Campus in Cornwall.
“New expertise undoubtedly offers us new alternatives, however our research reveals Secchi disks do a great job of estimating chlorophyll (a manner of measuring phytoplankton abundance) – which suggests we should always be capable to combine information from the previous with fashionable measurements.
“This offers us a priceless supply of long-term information on how our oceans are altering.”
Secchi disks are nonetheless used all world wide to observe ocean biomass and water high quality, and co-author Dr. Jaime Pitarch, from ISMAR, stated the findings help their continued use.
“It’s a easy, low cost device, however our analysis reveals it’s additionally remarkably efficient,” he stated.
In truth, researchers together with Dr. Brewin at Exeter, are engaged on a project that will use 3D-printed Secchi disks to observe water high quality in lakes in India and Africa, and coastal regions of the US.
Previous to the 1850s, mariners used quite a lot of objects (in the identical manner as Secchi disks) to assist with navigation, together with cloths, pans, and plates.
It was the Vatican astronomer Angelo Secchi, invited by the Papal Navy Commander Alessandro Cialdi to hitch a scientific cruise to check the murkiness of the ocean in 1865, who standardized the strategy.
The paper, revealed within the journal Frontiers in Marine Science, is entitled: “Evaluating historic and fashionable optical strategies for monitoring phytoplankton biomass within the Atlantic Ocean.”
Reference: “Evaluating historic and fashionable optical strategies for monitoring phytoplankton biomass within the Atlantic Ocean” by Robert J. W. Brewin, Jaime Pitarch, Giorgio Dall’Olmo, Hendrik J. van der Woerd, Junfang Lin, Xuerong Solar and Gavin H. Tilstone, 7 March 2023, Frontiers in Marine Science.
DOI: 10.3389/fmars.2023.1111416
The measurements within the new research have been collected on Atlantic Meridional Transect cruises. A UKRI Future Chief Fellowship funds Dr. Brewin’s work.
