Primary Producers are the organisms that in general convert inorganic materials (e.g., phosphate) into organic matter (e.g. lipids) through photosynthesis. In the aquatic realm, the dominant primary producers are the phytoplankton[1]. Primary Production relates to the amount of organic matter the Primary Producers build up over time, e.g. mg C / m3 / hr. Several methods exist to measure Primary Productivity: Adding radioactive tracers to a sample and measure the radioactive uptake after incubation; light-dark bottle technique comparing changes in dissolved oxygen; and various fluorescence techniques.

LISSTs cannot make any of these measurements. However, LISST data such as particle size distribution and concentration are still useful for certain aspects of primary productivity studies:

High-resolution LISST data on particle size and concentration have aided the assessment of phytoplankton abundance and distribution, essential for estimating primary productivity more accurately[i],[ii],[iii],[iv],[v],[vi],[vii].

They have also helped improving satellite-based remote sensing techniques[viii]. LISSTs provide insights into particle aggregation and flocculation processes influencing suspended particulate matter dynamics and light conditions, also affecting primary productivity [ix],[x],[xi],[xii].

Additionally, LISST data have been used to correlate particle size with chlorophyll concentrations and other biological metrics, offering a more comprehensive understanding of the biological pump and carbon sequestration processes[xiii],[xiv] ,[xv],[xvi].

While some articles do not directly link LISST instruments to primary productivity measurements, they emphasize the importance of particle dynamics in nutrient processing, which indirectly affects primary productivity [xvii], [xviii], [xix], [xx], [xxi].

[1] Bacteria can also convert inorganics into organics, and locally their role can be very significant. For the ocean, however, they are far less important than the phytoplankton.

[i] Hickey, B. M. et al. River Influences on Shelf Ecosystems: Introduction and synthesis. J. Geophys. Res.: Oceans 115, (2010).

[ii] Kostadinov, T. S., Siegel, D. A., Maritorena, S. & Guillocheau, N. Optical assessment of particle size and composition in the Santa Barbara Channel, California. Appl. Opt. 51, 3171 (2012).

[iii] Fettweis, M., Baeye, M., Zande, D., Eynde, D. & Lee, B. J. Seasonality of floc strength in the southern North Sea. J. Geophys. Res.: Oceans 119, 1911–1926 (2014).

[iv] Becker, K. W. et al. Daily changes in phytoplankton lipidomes reveal mechanisms of energy storage in the open ocean. Nat. Commun. 9, 5179 (2018).

[v] Helenius, L., Budge, S., Duerksen, S., Devred, E. & Johnson, C. L. Lipids at the plant–animal interface: a stable isotope labelling method to evaluate the assimilation of essential fatty acids in the marine copepod Calanus finmarchicus. J. Plankton Res. 41, 909–924 (2019).

[vi] Juranek, L. W. et al. The Importance of the Phytoplankton “Middle Class” to Ocean Net Community Production. Glob. Biogeochem. Cycles 34, (2020).

[vii] Renaud, P. E. et al. Extreme mismatch between phytoplankton and grazers during Arctic spring blooms and consequences for the pelagic food-web. Prog. Oceanogr. 229, 103365 (2024).

[viii] Bowers, D. G., Binding, C. E. & Ellis, K. M. Satellite remote sensing of the geographical distribution of suspended particle size in an energetic shelf sea. Estuar., Coast. Shelf Sci. 73, 457–466 (2007).

[ix] Fettweis, M., Baeye, M., Zande, D., Eynde, D. & Lee, B. J. Seasonality of floc strength in the southern North Sea. J. Geophys. Res.: Oceans 119, 1911–1926 (2014).

[x] Torregroza-Espinosa, A. C., Restrepo, J. C., Escobar, J., Brenner, M. & Newton, A. Nutrient inputs and net ecosystem productivity in the mouth of the Magdalena River, Colombia. Estuar., Coast. Shelf Sci. 243, 106899 (2020).

[xi] Wang, Y. & Gao, L. Sources and dynamics of suspended particulate matter in a large-river dominated marine system: Contributions from terrestrial sediments, biological particles, and flocculation. J. Mar. Syst. 225, 103648 (2022).

[xii] Asmala, E., Virtasalo, J. J., Scheinin, M., Newton, S. & Jilbert, T. Role of particle dynamics in processing of terrestrial nitrogen and phosphorus in the estuarine mixing zone. Limnol. Oceanogr. 67, 1–12 (2022).

[xiii] Juranek, L. W. et al. The Importance of the Phytoplankton “Middle Class” to Ocean Net Community Production. Glob. Biogeochem. Cycles 34, (2020).

[xiv] Kravchishina, M. et al. Influence of suspended particulate matter on the optical properties of seawater in the western Eurasian Arctic shelf. 28th Int. Symp. Atmos. Ocean Opt.: Atmos. Phys. 12341, 123414Z-123414Z–12 (2022).

[xv] Fukuda, H. et al. Temporal and regional variabilities in the attenuation of sinking particulate organic carbon in the Kuroshio region. Front. Mar. Sci. 9, 875362 (2022).

[xvi] Zhang, L. et al. Spatial variation of marine primary productivity over ridge and trough: A case study in the East China Sea. Cont. Shelf Res. 289, 105463 (2025).

[xvii] Scharf, F. S. et al. Seasonal and interannual patterns of distribution and diet of bluefish within a Middle Atlantic bight estuary in relation to abiotic and biotic factors. Estuaries 27, 426–436 (2004).

[xviii] Dall’Olmo, G. et al. Inferring phytoplankton carbon and eco-physiological rates from diel cycles of spectral particulate beam-attenuation coefficient. Biogeosciences 8, 3423–3439 (2011).

[xix] Larsen, L. G. & Harvey, J. W. Disrupted carbon cycling in restored and unrestored urban streams: Critical timescales and controls. Limnol. Oceanogr. 62, S160–S182 (2017).

[xx] Droujko, J. Increasing fine sediment source, flux, and connectivity understanding using novel measurement techniques and self-made turbidity sensors. (ETH Zürich, 2024).

[xxi] Karageorgis, A. P. et al. Particulate Matter Spatial, Temporal Distribution and Size Properties in the Aegean Sea. in 339–370 (2022). doi:10.1007/698_2022_899.