Salinity and Ocean Life

  • The ocean hosts 99% of all living space on earth.
    The ocean hosts 99% of all living space on earth.
  • Marine organisms range from microscopic viruses to giant blue whales.
    Marine organisms range from microscopic viruses to giant blue whales.
  • Each organism has specific needs in terms of habitat and food that it consumes.
    Each organism has specific needs in terms of habitat and food that it consumes.
  • Salinity plays a role in where many organisms live in the ocean.
    Salinity plays a role in where many organisms live in the ocean.
  • Sea surface salinity data help researchers determine likely locations of some marine organisms.
    Sea surface salinity data help researchers determine likely locations of some marine organisms.
1 2 3 4 5 6

“No water, no life. No blue, no green.” —Dr. Sylvia Earle

The ocean is vast, so finding specific organisms is vastly challenging. We can use environmental clues to hone in on areas where organisms might live. For example, searching for fish by watching for flocks of diving seabirds. But what if you need to look over a broader area? That’s where satellite data can come in handy!

Many environmental factors influence where specific types of organisms live in our ocean, including salinity. Salinities at the margins or outside the tolerance range of a particular species are “stressors.” Stressors can prevent a species occurrence, change their behavior, or limit reproduction… thus reducing their fitness for survival in that environment. In other words, you probably won’t find that species where such stressors exist.

There are many reasons we want to know where organisms live. We can identify target areas for maximum harvest. Conversely, we can use such information to protect them through targeted conservation efforts.

Click the stars on the map below to learn more about how researchers are using salinity data to find out where organisms live.

The map shows sea surface salinity during September 2017. It is based on Soil Moisture Active Passive (SMAP) data processed using the Jet Propulsion Laboratory’s Combined Active-Passive (JPL CAP) retrieval algorithm. More information on these maps can be found here here.

Related Publications

  • Ceríaco, L., Santos, B., de Lima, R., Bell, R., Norder, S. and Melo, M. (2022). Physical Geography of the Gulf of Guinea Oceanic Islands, In: Ceríaco, L.M.P., de Lima, R.F., Melo, M., Bell, R.C. (eds) Biodiversity of the Gulf of Guinea Oceanic Islands. Springer, Cham. https://doi.org/10.1007/978-3-031-06153-0_2.
  • Feng, Y., Huang, J., Du, Y., Balaguru, K., Ma, W., Feng, Q., Wan, X., Zheng, Y., Guo, X. and Cai, S. (2022). Drivers of Phytoplankton Variability in and Near the Pearl River Estuary, South China Sea During Typhoon Hato (2017): A Numerical Study, J. Geophys. Res. Biosciences, 127 (10), e2022JG006924, doi: 10.1029/2022JG006924.
  • Nordmo, T.-A., Kvalsvik, O., Kvalsund, S., Hansen, B., Halvorsen, P., Hicks, S., Johansen, D., Johansen, H. and Riegler, M. (2022). FishAI: Sustainable Commercial Fishing Challenge, Nordic Machine Intelligence, 2, 1-3, doi: 10.5617/nmi.9657.
  • Carlson, M., Ribalet, F., Maidanik, I., Durham, B., Hulata, Y., Ferrón, S., Weissenbach, S., Shamir, N., Goldin, S., Baran, N., Cael, B., Karl, D., White, A., Armbrust, V., and Lindell, D. (2022). Viruses affect Picocyanobacterial Abundance and Biogeography in the North Pacific Ocean, Nat. Microbiol. 7, 570–580, doi: 10.1038/s41564-022-01088-x.
  • Jiang, X., Dong, C., Ji, Y., Wang, C., Shu, Y., Liu, L., and Ji, J. (2021). Influences of Deep-Water Seamounts on the Hydrodynamic Environment in the Northwestern Pacific Ocean, J. Geophys. Res. Oceans, 126(12), e2021JC017396, doi: 10.1029/2021JC017396.
  • Yoon, J.-E., Son, S., and Kim, I.-N. (2021). Capture of Decline in Spring Phytoplankton Biomass Derived from COVID-19 Lockdown Effect in the Yellow Sea Offshore Waters, Mar. Pollut. Bull., 174, 113175, doi: 10.1016/j.marpolbul.2021.113175.
  • Belmadani, A., Auger, P.-A., Gomez, K., Maximenko, N., and Cravatte, S. (2021). Similarities and Contrasts in Stationary Striations of Surface Tracers in Pacific Eastern Boundary Upwelling Systems, Preprints, 2021060207, doi: 10.20944/preprints202106.0207.v1.
  • Belkin, I. (2021). Remote Sensing of Ocean Fronts in Marine Ecology and Fisheries, Remote Sens. 2021, 13(5), 883, doi: 10.3390/rs13050883.
To view all salinity publications, visit the publications page.
Salinity Quiz
How Salty (or Fresh) Are You? Take our four-question quiz to discover which habitat and organism most closely matches your own preferences.

Featured Publications

Heavy rain over the ocean

Conserving key habitats for wildlife conservation can be challenging. Conserving key habitats for species that move to different places throughout the year is extra challenging. This study presents a multi-species assessment of year-round habitat patterns for five species of sea ducks in eastern North America as they migrate from boreal/arctic terrestrial breeding sites to coastal, aquatic non-breeding habitats. By examining multiple species of ducks across their annual migration, researchers identified key habitat features (including surface salinity) and periods of vulnerability to create an annual cycle conservation strategy.


Lamb, J.S., Paton, P.W.C., Osenkowski, J.E., Badzinski, S.S., Berlin, A.M., Bowman, T., et al. 2020. View the full paper.

Figure Caption

Maps of habitat suitability scores for five species of sea ducks during the fall, post-breeding period. Darker colors indicate higher suitability of the habitat.

NOAA mooring at sunset

Extremophiles are organisms that thrive in the harshest environments on earth, such as extreme heat, salinity, radiation, pollutants, pH, or pressure. These microorganisms and the enzymes they produce to survive these extreme conditions are a key resource in the development of biofuels, bioremediation, and biotechnology. Finding these organisms, however, can be a challenge. In this study, researchers use satellite salinity data to hone in on areas to look for halophiles - extremophiles that thrive in high salinity environments.


Donato, P.D., Buono, A., Poli, A., Finore, I., Abbamondi, G.R., Nicolaus B., and Lama, L. 2018. View the full paper.

Figure Caption

Monthly average global sea surface salinity. Areas with salinity over 38 psu (orange to red) are likely areas to find extremophiles. Source: SMAP JPL CAP Monthly Data, September 2021.

Argo deployment

The Amazon River pours 5 trillion cubic meters into the Atlantic Ocean every year. That’s more than enough water to fill the Grand Canyon to the brim. As this freshwater mixes with seawater and becomes entrained into ocean currents, it influences the growth of phytoplankton. In this study, researchers developed a model to determine the extent to which salinity “explained” – i.e., influenced, limited, determined – how much primary production occurred in a given area.


Gouveia, N.A., Gherardi, D.F.M., Wagner, F.H., Paes, E.T., Coles, V.J., and Aragão, L.E.O.C. 2019. View full the paper.

Figure Caption

Spatial limitation of primary production as a result of the Amazon River Plume. LEFT: Model results depicting the level to which salinity influences primary production. Blues indicate areas where production was less influenced by salinity and reds indicate areas that were more influenced. RIGHT: Location of the Amazon River plume waters, delineated by salinity.