Organic matter: does size matter?
- José Luis García
- Dec 7, 2022
- 2 min read
The Bentayga is an eddy that rotates clockwise, which affects how the organic matter produced and used by organisms that inhabit the ocean is distributed. Organic matter is made up of myriads of chemical compounds based on carbon atoms, forming carbon-carbon or carbon-hydrogen bonds. It can be divided into dissolved and particulate, depending on its size, and the limit is dictated by the pore size used to filter the water (between 0.2 and 0.7 micrometers).
José Luis filtering water to collect particulate organic matter (left) and an example of a filter with particles from the sediment traps (right)
Dissolved organic matter represents 97% of all organic matter in the ocean and represents one of the largest reservoirs of organic carbon on the planet. The highest concentration is found on the surface ocean, where the effect of the Bentayga is most noticeable. 95% of the dissolved organic matter comes directly or indirectly from phytoplankton, which are the organisms responsible for photosynthesis in the sea, and the remaining 5% from terrestrial or atmospheric sources. The functions of dissolved organic matter in the ocean are diverse, intervening in carbon dynamics in the ocean (Biological Carbon Pump), buffering and contributing to water alkalinity, complexing trace metals or damping the damaging effect of UV radiation on organisms inhabiting the ocean.
Particulate organic matter is made up of all living organisms that inhabit the ocean, and fundamentally, by particles of sizes ranging from micrometers to centimeters. These particles can be found in suspension or sedimentation more or less rapidly in the water column, being their main source waste materials from marine trophic webs. As they are larger, these particles sink, transporting carbon and other elements from the surface to the bottom of the sea, contributing to the Biological Carbon Pump.
In an eddy like the Bentayga we are observing that the main fractions of organic matter are dissolved and particulate matter in suspension and, therefore, the vertical transport of this matter dominates the flow of large particles, in sedimentation by gravity.
Really clear breakdown of the dissolved vs. particulate split — the 0.2–0.7 μm pore-size cutoff is one of those details that trips up a lot of students, and framing it around the Bentayga eddy makes the vertical-transport story much easier to picture. The point about 95% of DOM tracing back to phytoplankton is a great reminder of how tightly the biological carbon pump is coupled to primary production.
I ended up saving this to my notes while reading. As a small tip for anyone doing the same: I keep my study notes in Markdown and use a free viewer to render them cleanly (equations, tables, diagrams) without any install mark down viewer has been handy for that. Thanks for the…
ไม้สน (Pine Wood) เป็นวัสดุยอดนิยมในงานตกแต่งภายในและงานเฟอร์นิเจอร์ เพราะมีเอกลักษณ์เฉพาะตัวที่หาตัวจับยาก แต่ก็มีข้อควรระวังในการใช้งานที่ต้องพิจารณาให้เหมาะสมกับประเภทของงานครับ
http://khaimai.com/%E0%B9%84%E0%B8%A1%E0%B9%89%E0%B8%9D%E0%B8%B2/
This study on the role of organic matter size in marine ecosystems is a fascinating deep dive into oceanographic processes. For researchers and students accessing these detailed papers and datasets remotely, ensuring a stable connection is vital, and a quick SatSpeedCheck is an excellent way to guarantee uninterrupted access to this important work.
Thanks for this deep dive into organic matter, José Luis! The distinction between dissolved and particulate matter, and the specific size limits, was particularly well-explained. It reminds me how satisfying it is to put logical pieces together, much like I enjoy a good brain teaser like MeowdoKu in my downtime.
The discussion around the Biological Carbon Pump and the movement of particulate organic matter was very clear. It's amazing to think about the vast scale of these processes. After absorbing all this great scientific information, sometimes I need a quick mental break, and a game like StonkRider can be a fun way to reset.