Idea or model
Ocean zones
The ocean is layered by depth. Only the upper 200 meters gets enough light for photosynthesis, and below 1,000 meters it is completely dark.
Marine Biology
Life in the ocean, from the sunlit surface to deep-sea vents.
Marine biology is the study of life in the ocean, from tiny plankton to whales.
Marine biologists study ocean zones, plankton, coral reefs and deep-sea life, including communities that run on chemical energy at hydrothermal vents.
Topics include primary production by phytoplankton such as Prochlorococcus, coral bleaching during marine heatwaves, bioluminescence and chemosynthetic symbioses.
Big questions
- How does life survive in the dark deep sea?
- Why do corals bleach?
- How much of Earth's photosynthesis happens in the ocean?
Key ideas
Open any idea in the knowledge graph to see what it connects to, here and in other fields.
Organism or group
Phytoplankton
Microscopic photosynthetic organisms drifting in sunlit water. Ocean producers account for roughly half of the carbon fixed on Earth each year.
Organism or group
Prochlorococcus
The smallest known photosynthetic organism, about half a micrometer across. The ocean holds an estimated 2.9 × 10²⁷ of these cells.
Process
Coral bleaching
When water is too warm, corals expel the algae living in their tissues and turn white. Record heat in 2015 and 2016 caused the third global bleaching event since the 1980s.
Process
Bioluminescence
Light made by living things. In surveys off California, about three-quarters of the observed animals could make light.
Structure
Hydrothermal vents
Hot springs on the seafloor, first explored on the Galápagos Rift in the late 1970s, where whole communities run on chemical energy.
Process
Chemosynthesis
Making food from chemical energy instead of light. At vents, bacteria inside tube worms oxidize hydrogen sulfide to feed their hosts.
Process
Primary production
Carbon fixed by plants, algae and photosynthetic microbes: about 105 billion tonnes a year worldwide, roughly half on land and half in the ocean.
Also in Marine Biology
Explore it in the labs
Interactive explorer
Compare bacteria, archaea, fungi, protists and viruses side by side, and model how a bacterial culture grows.
- Microbiology
- Evolution
- Immunology
Simulation
Change temperature, rainfall, soil and populations in a plant, herbivore and predator food chain, and watch the whole web respond.
- Ecology
- Plant Biology
- Evolution
Current research
Search published papers and preprints in Marine Biology, with clear labels for reviews, primary research, clinical trials and preprints.
Search papers in Marine BiologySources & further reading
The explanations on this page are our own summaries of these sources. Follow a link to read the original; if anything here disagrees with it, the original wins. How we choose and check sources.
How far does light travel in the ocean? (opens the original in a new tab)
NOAA National Ocean Service. oceanservice.noaa.gov. National Oceanic and Atmospheric Administration.
Fact sheetGovernment sourcePrimary production of the biosphere: integrating terrestrial and oceanic components (opens the original in a new tab)
Field CB, Behrenfeld MJ, Randerson JT, et al. (1998). Science 281:237-240.
Global net primary production of about 105 petagrams of carbon per year, split roughly evenly between land and ocean.
Peer-reviewedPrimary researchGlobal warming and recurrent mass bleaching of corals (opens the original in a new tab)
Hughes TP, Kerry JT, Álvarez-Noriega M, et al. (2017). Nature 543:373-377.
Peer-reviewedPrimary researchLayers of the Ocean (opens the original in a new tab)
NOAA JetStream. noaa.gov. National Oceanic and Atmospheric Administration.
ReferenceGovernment sourceEducationalWhat are phytoplankton? (opens the original in a new tab)
NOAA National Ocean Service. oceanservice.noaa.gov. National Oceanic and Atmospheric Administration.
Fact sheetGovernment sourceProchlorococcus, a marine photosynthetic prokaryote of global significance (opens the original in a new tab)
Partensky F, Hess WR, Vaulot D (1999). Microbiology and Molecular Biology Reviews 63:106-127.
Peer-reviewedReviewPresent and future global distributions of the marine Cyanobacteria Prochlorococcus and Synechococcus (opens the original in a new tab)
Flombaum P, Gallegos JL, Gordillo RA, et al. (2013). Proceedings of the National Academy of Sciences 110:9824-9829.
Peer-reviewedPrimary researchWhat is coral bleaching? (opens the original in a new tab)
NOAA National Ocean Service. oceanservice.noaa.gov. National Oceanic and Atmospheric Administration.
Fact sheetGovernment sourceWhat is bioluminescence? (opens the original in a new tab)
NOAA Ocean Exploration. oceanexplorer.noaa.gov. National Oceanic and Atmospheric Administration.
Fact sheetGovernment sourceQuantification of bioluminescence from the surface to the deep sea demonstrates its predominance as an ecological trait (opens the original in a new tab)
Martini S, Haddock SHD (2017). Scientific Reports 7:45750.
In 17 years of video off California, 76% of observed animals were capable of bioluminescence.
Peer-reviewedPrimary researchBioluminescence in the ocean: origins of biological, chemical, and ecological diversity (opens the original in a new tab)
Widder EA (2010). Science 328:704-708.
Peer-reviewedReviewSubmarine thermal springs on the Galápagos Rift (opens the original in a new tab)
Corliss JB, Dymond J, Gordon LI, et al. (1979). Science 203:1073-1083.
Report of the first hydrothermal vent communities observed on the sea floor.
Peer-reviewedPrimary researchFactsheet: Hydrothermal Vents (opens the original in a new tab)
NOAA Ocean Exploration. oceanexplorer.noaa.gov. National Oceanic and Atmospheric Administration.
Fact sheetGovernment sourcePhotosynthesis vs. Chemosynthesis (opens the original in a new tab)
NOAA Pacific Marine Environmental Laboratory. pmel.noaa.gov. National Oceanic and Atmospheric Administration.
ReferenceGovernment sourceEducationalProkaryotic cells in the hydrothermal vent tube worm Riftia pachyptila Jones: possible chemoautotrophic symbionts (opens the original in a new tab)
Cavanaugh CM, Gardiner SL, Jones ML, et al. (1981). Science 213:340-342.
Peer-reviewedPrimary research