Reference

Glossary

Every key term, then every name, place and institution in the atlas, A to Z.

Search 234 terms and 261 names

Key terms

30x30: A global biodiversity target to protect 30 percent of the world's land and ocean area by 2030.D.3See alsoMarine protected area, Locally managed marine area (LMMA), BBNJ Agreement

Abyssal hill: A small volcanic hill on the deep ocean floor, among the most common landforms on Earth.Volume 02See alsoAbyssal plain, Seamount, Seafloor spreading
Abyssal plain: A flat expanse of deep ocean floor, typically between about 3,000 and 6,000 meters deep.D.1See alsoMarine snow, Sediment core, Abyssal hill, Hadal zone
Additionality: The requirement that a carbon credit represent emissions reductions or removals that would not have occurred without the specific funded project.D.2See alsoBlue carbon credit, Payment for ecosystem services, Carbon offset
Age of Discovery: The fifteenth to seventeenth centuries, when European powers launched major transoceanic voyages.Volume 01See alsoCircumnavigation, Carrack and caravel, Portolan chart
Albedo effect: The reflection of solar radiation by a bright surface such as ice; as ice melts, the darker ocean absorbs more heat, reinforcing warming.C.3See alsoSea ice, Heat capacity, Ocean heat content
AMOC: The Atlantic Meridional Overturning Circulation, a system of currents that carries warm water north and cold water south in the Atlantic Ocean.C.2See alsoThermohaline circulation, Deep water formation
Annona: The Roman state system that guaranteed grain supply to Rome via maritime shipping routes.2.3
Apex predator: An animal at the top of a food web with no natural predators.Volume 03See alsoTrophic cascade, Keystone species
Aquaculture: Farming fish, shellfish or seaweed under controlled conditions.Volume 04See alsoIntegrated multi trophic aquaculture (IMTA), Polyculture, Mariculture
Asthenosphere: The weak, slowly flowing mantle layer beneath the lithosphere over which tectonic plates move.Volume 01See alsoLithosphere, Subduction zone

Banded iron formation: Layered sedimentary rock of iron oxides and silica that records ancient ocean chemistry.1.3See alsoGreat Oxidation Event, Cyanobacteria, Stromatolite
Bathypelagic zone: The open water layer roughly between 1,000 and 4,000 meters deep, also called the midnight zone.B.3See alsoHadal zone, Mesopelagic zone, Piezophile
BBNJ Agreement: The 2023 international treaty on the conservation and sustainable use of marine biological diversity in areas beyond national jurisdiction, also called the High Seas Treaty.C.1See alsoExclusive economic zone (EEZ), Marine protected area, 30x30
Benthic zone: The seafloor and the life that lives on or in it.Volume 02See alsoHadal zone, Abyssal plain
Bill of lading: A carrier's legal document listing the type, quantity and destination of shipped goods.Volume 04See alsoMarine insurance, Containerization
Bioerosion: The wearing down of reef or rock by living things such as sponges, worms or parrotfish.Volume 03See alsoReef building coral, Calcification
Biological pump: The set of processes that transport carbon from the surface ocean to deep water.A.3See alsoSolubility pump, Export production, Deep scattering layer, Diel vertical migration
Bioluminescence: Light produced by a living organism through a chemical reaction.B.3See alsoMesopelagic zone, Deep scattering layer, Symbiotic bacteria
Biomass: The total mass of living things in a given area or layer.Volume 03See alsoCarrying capacity, Krill
Black smoker: A hydrothermal vent that emits dark, mineral laden water due to high concentrations of sulfide particles.D.2See alsoHydrothermal vent, Chemosynthesis, Cold seep
Bloom: A rapid increase in phytoplankton numbers, usually tied to light and nutrient availability.A.2See alsoPhytoplankton, Diatom, Chlorophyll
Blue bond: A loan instrument that raises money for ocean conservation or sustainable marine projects.Volume 04See alsoBlue carbon credit, Debt-for-nature swap
Blue carbon: Carbon captured and stored by coastal and marine ecosystems such as mangroves, seagrass and salt marshes.C.1 D.2See alsoMangrove, Seagrass, Salt marsh, Blue carbon credit
Blue carbon credit: A tradable certificate representing a verified amount of carbon stored or avoided through the protection or restoration of coastal ecosystems.A.3See alsoBlue carbon, Natural capital accounting, Payment for ecosystem services
Blue corridor: A migratory route used consistently by marine species, often crossing multiple national waters.B.1See alsoNatal homing, Pelagic zone, Ecosystem connectivity
Blue economy: Economic use of the ocean that aims to keep marine ecosystems healthy.Volume 04See alsoNatural capital, Ecosystem services
Bottom trawling: A fishing method that drags heavy nets along the seafloor, often damaging slow growing habitat.E.5 B.4See alsoMaximum sustainable yield, Marine protected area
Brine rejection: The release of salt into surrounding water as sea ice forms, making that water denser.Volume 02See alsoSea ice, Deep water formation, Salinity
Buccaneer: A Caribbean pirate or privateer of the seventeenth century, often targeting Spanish shipping.Volume 01See alsoPrivateer, Golden Age of Piracy
Buffer zone: An area that absorbs disturbance, such as floodwater or pollutants, before it reaches a more sensitive area.C.3See alsoMarine protected area, Locally managed marine area (LMMA)
Bulk carrier: A ship built to carry loose cargo such as grain, coal or ore.Volume 04See alsoLiner, Flag of convenience

Calcification: How marine organisms build shells or skeletons from calcium carbonate.Volume 03See alsoCalcifying organism, Ocean acidification, Reef building coral
Calcifying organism: An organism such as a coral, oyster or certain plankton that builds hard structures from calcium carbonate.D.3See alsoOcean acidification, pH scale, Calcification
Cambrian explosion: A relatively rapid diversification of complex animal life that began about 540 million years ago.1.5See alsoTerrestrialization, Food web, Trophic level
Carbon offset: A credit for a cut or removal of emissions, used to compensate for emissions elsewhere.Volume 04See alsoBlue carbon credit, Additionality
Carbon sink: A natural system, such as the ocean or a forest, that absorbs more carbon from the atmosphere than it releases.D.1 C.2
Carrack and caravel: Ship types used by Portuguese and Spanish explorers, designed for long ocean voyages.3.2See alsoCircumnavigation, Age of Discovery, Lateen sail
Carrying capacity: The maximum level of visitor use or development an ecosystem or destination can sustain without significant degradation.B.3See alsoMaximum sustainable yield, Biomass, Tragedy of the commons
Chartered company: A company granted government-sanctioned monopoly trading rights and quasi-sovereign powers over distant territory.4.1See alsoJoint-stock company, Trading post, Treasure fleet
Chemical evolution: The gradual process by which simple molecules combined into more complex ones before biology existed.Volume 01See alsoPrebiotic chemistry, Hydrothermal vent, Stromatolite
Chemosynthesis: The process by which some organisms produce food using chemical energy instead of sunlight.D.2See alsoHydrothermal vent, Black smoker, Cold seep
Chlorophyll: The green pigment that lets phytoplankton and plants capture sunlight.Volume 03See alsoPhytoplankton, Bloom, Diatom
Circumnavigation: A complete voyage around the world, first achieved by the remnants of Magellan's expedition in 1519 to 1522.3.2See alsoCarrack and caravel, Age of Discovery, Rhumb line
Classification society: An organization that sets and checks technical standards for ship design and safety.Volume 04See alsoPort state control, Marine insurance
Coaling station: A port facility supplying coal fuel for steamships on long-distance routes.4.2See alsoLiner, Transatlantic telegraph cable
Cold seep: A site where gases, usually methane, escape from the seafloor without being heated by magma.D.3See alsoChemosynthesis, Black smoker, Methane
Compass rose: A figure on a chart showing the main and intermediate directions.Volume 01See alsoPortolan chart, Rhumb line
Compensation depth: The depth at which photosynthesis and respiration in a plankton cell are equal.A.1See alsoPhotic zone, Euphotic, Phytoplankton
Containerization: The system of transporting cargo in standardized, stackable intermodal containers.4.3See alsoIntermodal transport, Liner, Twenty-foot equivalent unit (TEU)
Coral atoll: A ring shaped reef and island formed around a sunken volcanic peak.Volume 03See alsoReef building coral, Guyot
Coral bleaching: The loss of symbiotic algae and color in corals under heat or other stress.E.2See alsoZooxanthellae, Marine heatwave, Reef building coral
Coral polyp: A small, soft bodied animal that builds a calcium carbonate skeleton and forms reef structures in colonies.E.1See alsoReef building coral, Zooxanthellae, Calcification
Coriolis effect: The apparent deflection of moving fluids caused by Earth's rotation, curving currents right in the north and left in the south.A.3See alsoGyre, Western boundary current
Cyanobacteria: Photosynthetic microbes credited with producing the first significant oxygen on Earth.1.3See alsoGreat Oxidation Event, Banded iron formation, Stromatolite

Dead zone: An area of water with oxygen levels too low to support most marine animal life, often caused by nutrient pollution and warming.D.4 C.3See alsoNutrient cycling, Stratification
Debt-for-nature swap: A deal that cuts a country's debt in exchange for funding conservation.Volume 04See alsoBlue bond, Marine protected area
Decarbonization: Reducing carbon dioxide emissions from an economy or industry.Volume 04See alsoGreen methanol, Stranded asset, Divestment
Deep scattering layer: A dense band of animals detected by sonar that rises and sinks each day.Volume 03See alsoDiel vertical migration, Mesopelagic zone
Deep sea mining: Extracting minerals, such as polymetallic nodules, from the deep seafloor.Volume 04See alsoPolymetallic nodules
Deep water formation: The sinking of cold, salty surface water that drives deep circulation.Volume 02See alsoThermohaline circulation, AMOC, Brine rejection
Deuterium: A heavy form of hydrogen with one extra neutron. Its ratio to normal hydrogen acts as a fingerprint of water's origin.1.1See alsoLate heavy bombardment, Outgassing
Dhow: A traditional Arab sailing vessel with a triangular lateen sail, well suited to monsoon winds.2.4See alsoMonsoon trade route, Lateen sail, Spice trade
Diatom: A common group of phytoplankton with cell walls made of silica.A.2See alsoPhytoplankton, Bloom, Chlorophyll
Diel vertical migration: The daily cycle of animals moving up at night and down during the day.A.3See alsoMesopelagic zone, Deep scattering layer, Biological pump
Divestment: The withdrawal of investment, often for ethical or risk related reasons, from companies or sectors engaged in a targeted activity.C.4See alsoStranded asset, Decarbonization, Carbon offset
Double-hulled canoe: A voyaging canoe built from two parallel hulls, stable and roomy enough for long ocean crossings.Volume 01See alsoOutrigger canoe, Wayfinding

Ecosystem connectivity: The degree to which separate habitats and ecosystems are linked by the movement of species, nutrients or water.E.4See alsoLarval dispersal, Spillover effect, Blue corridor
Ecosystem engineer: A species that physically modifies its habitat in ways that create conditions for other species.E.3See alsoKeystone species, Oyster reef, Reef building coral
Ecosystem services: The benefits people obtain from ecosystems, including regulating services like climate control and provisioning services like food.A.1See alsoNatural capital, Externality, Payment for ecosystem services
Endemic species: A species found naturally in only one region.Volume 03See alsoMarine biodiversity hotspot
Epipelagic zone: The sunlit upper layer of the open ocean, roughly the top 200 metres.Volume 02See alsoPhotic zone, Mesopelagic zone, Pelagic zone
Estuary: A partially enclosed coastal body of water where fresh river water mixes with salty ocean water.A.4See alsoSalt marsh, Tidal flushing, Longshore drift
Euphotic: A term for water that still receives about 1 percent or more of surface sunlight.A.1See alsoPhotic zone, Compensation depth, Phytoplankton
Exclusive economic zone (EEZ): A sea zone extending up to 200 nautical miles from a coastal state's shore, within which it has special rights over resource exploration and use.C.1See alsoMarine spatial planning, Institutional capacity
Export production: The portion of organic carbon produced near the surface that sinks out of the upper ocean into deeper water.D.2See alsoBiological pump, Nutrient cycling, Solubility pump
Externality: A cost or benefit of an activity that falls on third parties and is not reflected in its market price, such as pollution or habitat loss.A.1See alsoNatural capital, Tragedy of the commons, Ecosystem services

Fetch: The uninterrupted distance over open water that wind blows, which together with wind speed and duration determines wave size.A.1See alsoSwell, Rogue wave, Internal wave
Filter feeder: An organism that feeds by straining suspended particles and plankton out of water.E.3See alsoOyster reef, Ecosystem engineer
Fisheries subsidy: Public money given to fishing fleets, which can drive overfishing when poorly designed.Volume 04See alsoMaximum sustainable yield, Tragedy of the commons
Flag of convenience: A registration of a ship in a country other than that of its owners, often chosen for lower regulatory or tax costs.B.1See alsoPort state control, Classification society, Bulk carrier
Floating offshore wind: Wind turbines mounted on floating platforms anchored to the seabed, allowing deployment in waters too deep for fixed foundations.B.5See alsoOffshore wind farm, Tidal stream turbine
Food web: The network of feeding links between organisms in an ecosystem.Volume 03See alsoTrophic cascade, Trophic level, Keystone species

Geobukseon: Korean armored turtle ships used defensively against 16th century Japanese invasions.3.1See alsoTreasure fleet
Golden Age of Piracy: Roughly the 1650s to the 1730s, when piracy was widespread in the Atlantic and Caribbean.Volume 01See alsoBuccaneer, Privateer, Pirate code
Great Oxidation Event: The period, roughly 2.4 to 2.0 billion years ago, when atmospheric oxygen rose sharply.1.3See alsoCyanobacteria, Banded iron formation, Stromatolite
Green methanol: A methanol fuel produced from renewable electricity or biomass rather than fossil natural gas, used to cut shipping emissions.B.1See alsoDecarbonization, Flag of convenience
Guyot: A flat topped seamount, formed when a volcanic island erodes and sinks below sea level.Volume 02See alsoSeamount, Hotspot volcanism, Coral atoll
Gyre: A large system of rotating ocean currents, typically centered on an entire ocean basin.A.3See alsoCoriolis effect, Western boundary current

Hadal zone: The deepest ocean zone, found in trenches below about 6,000 meters, named after Hades.B.4 D.1See alsoOcean trench, Bathypelagic zone, Piezophile
Halocline: A layer where salinity changes sharply with depth.Volume 02See alsoPycnocline, Salinity, Thermocline
Heat capacity: The amount of heat energy required to raise the temperature of a substance, which is very high for water compared to air or rock.C.1See alsoOcean heat content, Ocean-atmosphere coupling, Albedo effect
Holdfast: The root like structure that anchors a kelp plant to the seafloor.C.4See alsoKelp forest, Urchin barren, Keystone species
Hotspot volcanism: Volcanism over a fixed mantle plume, producing island chains as plates move over it.Volume 02See alsoSeamount, Guyot
Hydrothermal vent: A fissure on the seafloor releasing heated, mineral-rich water, proposed as one possible cradle for early chemistry.1.2 B.3See alsoChemosynthesis, Black smoker, Cold seep

Illegal, unreported and unregulated (IUU) fishing: Fishing activity that violates national or international rules, or that goes unreported to relevant authorities, undermining stock management.B.4
Institutional capacity: A government's practical ability to design, implement and enforce policy, including staffing, funding, technical expertise and monitoring systems.D.6See alsoExclusive economic zone (EEZ), Social licence to operate, Marine spatial planning
Integrated multi trophic aquaculture (IMTA): An aquaculture design combining species such as fish, shellfish and seaweed so that nutrient waste from one is used as food or filtration input by another.D.4See alsoAquaculture, Polyculture, Mariculture
Intermodal transport: Freight transport using multiple modes, such as ship, rail and truck, without unloading the cargo itself.4.3See alsoContainerization, Liner, Twenty-foot equivalent unit (TEU)
Internal wave: A wave that travels along a density boundary inside the ocean rather than at the surface.Volume 02See alsoPycnocline, Stratification
Invasive species: A non native organism that causes ecological or economic harm where it is introduced.Volume 03See alsoEcosystem connectivity, Trophic cascade

Joint-stock company: A business structure allowing many investors to hold tradable shares and share risk, pioneered at scale by the VOC.3.4See alsoChartered company, Trading post
Just transition: Changing an economy while protecting the workers and communities affected.Volume 04See alsoDecarbonization, Stranded asset, Social licence to operate

Kelp forest: A dense underwater forest of large brown algae that shelters coastal life.Volume 03See alsoHoldfast, Urchin barren, Keystone species
Keystone species: A species whose presence has an outsized effect on the structure of its ecosystem.C.4See alsoTrophic cascade, Apex predator, Ecosystem engineer
Krill: Small shrimp like crustaceans that form a major food source for many whale species.B.2See alsoWhale pump, Biomass, Food web

Larval dispersal: The drift of young marine animals on currents before they settle.Volume 03See alsoSpillover effect, Nursery habitat, Ecosystem connectivity
Late heavy bombardment: A period of intense asteroid and comet impacts on the young Earth, roughly 4 billion years ago.1.1See alsoDeuterium, Outgassing, Prebiotic chemistry
Lateen sail: A triangular sail that let ships sail closer to the wind.Volume 01See alsoCarrack and caravel, Dhow
Latent heat: Energy released when water vapor condenses into liquid droplets, a key fuel source for storms and hurricanes.C.3See alsoHeat capacity, Tropical cyclone, Ocean-atmosphere coupling
Letter of marque: An official license authorizing a private ship to attack and seize enemy vessels.3.6See alsoPrivateer, Pirate code, Golden Age of Piracy
Library of Alexandria: An ancient center of scholarship that collected manuscripts on navigation, astronomy and geography.2.2
Liner: A large ship operating on a fixed, scheduled route, as opposed to irregular voyages.4.2See alsoContainerization, Coaling station, Bulk carrier
Lithosphere: Earth's rigid outer shell, the crust and uppermost mantle, broken into tectonic plates.Volume 01See alsoAsthenosphere, Mid-ocean ridge, Subduction zone
Locally managed marine area (LMMA): A nearshore marine area managed largely by the coastal community that depends on it, often combining traditional and modern management tools.D.5See alsoMarine protected area, Social licence to operate, Spillover effect
Longitude problem: The historical challenge of finding a ship's east to west position at sea.Volume 01See alsoMarine chronometer, Portolan chart, Compass rose
Longship: A long, narrow, shallow-draft Viking vessel designed for speed on both open sea and rivers.2.5See alsoWayfinding, Sunstone
Longshore drift: The transport of sediment along a coastline caused by waves approaching the beach at an angle.A.4See alsoRip current, Estuary

Mangrove: A salt tolerant coastal tree forming forests that protect shores and store blue carbon.Volume 03See alsoPneumatophore, Blue carbon, Nursery habitat
Mariculture: Aquaculture in seawater or coastal environments.Volume 04See alsoAquaculture, Integrated multi trophic aquaculture (IMTA)
Marine biodiversity hotspot: A region with an exceptionally high number of marine species, often under threat.Volume 03See alsoEndemic species, Coral bleaching
Marine chronometer: A precise sea clock used to calculate longitude during long voyages.Volume 01See alsoLongitude problem, Rhumb line
Marine heatwave: A prolonged period of unusually warm ocean water that can trigger widespread coral bleaching.E.2See alsoCoral bleaching, Species range shift, Ocean heat content
Marine insurance: Financial coverage against the loss of ships or cargo, developed extensively in 17th century London.3.4See alsoBill of lading, Classification society
Marine protected area: A defined ocean area where human activity, especially fishing, is restricted to protect ecosystems.E.5See also30x30, Locally managed marine area (LMMA), Marine spatial planning
Marine snow: A continuous shower of organic particles, dead organisms and waste falling from upper ocean layers to the deep seafloor.B.1 B.3See alsoAbyssal plain, Sediment core, Export production
Marine spatial planning: Organizing human activities across ocean space to reduce conflict and harm.Volume 04See alsoExclusive economic zone (EEZ), Marine protected area
Maximum sustainable yield: The largest catch or extraction rate that a renewable resource can sustain indefinitely without declining.A.2See alsoCarrying capacity, Tragedy of the commons, Fisheries subsidy
Mesopelagic zone: The twilight layer of the ocean, roughly between 200 and 1,000 meters deep.A.3See alsoBathypelagic zone, Diel vertical migration, Deep scattering layer
Methane: A gas commonly released at cold seeps, used as an energy source by chemosynthetic bacteria.D.3See alsoCold seep, Chemosynthesis, Outgassing
Microplastic: A small plastic fragment, generally under 5 millimeters, formed from the breakdown of larger plastic waste.E.5See alsoDead zone, Externality
Mid-ocean ridge: An underwater mountain chain where tectonic plates separate and new oceanic crust is created.1.4See alsoSeafloor spreading, Subduction zone, Wilson cycle
Middle Passage: The forced transatlantic crossing endured by enslaved Africans under brutal conditions.3.5See alsoTriangular trade
Monsoon: A seasonal wind system that reverses direction roughly twice a year, historically used to time ocean voyages.2.4 C.3See alsoMonsoon trade route, Dhow, Trade winds
Monsoon trade route: A seasonal Indian Ocean route that relied on predictable reversing monsoon winds.Volume 01See alsoMonsoon, Dhow, Trade winds
Multibeam sonar: A sonar system that emits multiple simultaneous beams to map a wide swath of seafloor depth and shape in a single pass.C.2See alsoSeabed 2030, Seamount

Natal homing: The tendency of an animal to return to the area where it was born to reproduce.B.1See alsoBlue corridor, Pelagic zone, Spawning aggregation
Natural capital: The stock of natural assets, such as oceans, forests and soils, that produce a flow of goods and services over time if not degraded faster than they regenerate.A.1See alsoEcosystem services, Externality, Natural capital accounting
Natural capital accounting: A statistical framework that records the stocks and flows of natural assets alongside conventional economic accounts.A.3See alsoNatural capital, Blue carbon credit, Payment for ecosystem services
Nilometer: An ancient device used to measure the Nile's flood level to predict harvests.2.2
Nursery habitat: A sheltered area where juvenile marine animals grow before moving to open water.C.1See alsoLarval dispersal, Mangrove, Spawning aggregation
Nutrient cycling: The movement and reuse of elements such as nitrogen and phosphorus through an ecosystem.Volume 03See alsoWhale pump, Upwelling, Export production

Ocean acidification: A decrease in ocean pH caused by absorption of carbon dioxide, which makes it harder for corals to build skeletons.E.2See alsopH scale, Calcifying organism, Calcification
Ocean heat content: The total amount of heat stored in the ocean, used by scientists to track long term warming trends.C.1See alsoMarine heatwave, Heat capacity, Ocean-atmosphere coupling
Ocean resilience: The capacity of marine ecosystems to absorb disturbance and still maintain their basic structure and function.E.4
Ocean rewilding: Restoring marine ecosystems and populations toward a less disturbed state.Volume 03See alsoTrophic cascade, Marine protected area
Ocean thermal energy conversion (OTEC): A technology that generates electricity from the temperature difference between warm surface seawater and cold deep seawater.D.1
Ocean trench: A long, narrow seafloor depression formed where one plate sinks beneath another.Volume 02See alsoSubduction zone, Hadal zone, Piezophile
Ocean-atmosphere coupling: The exchange of heat, moisture and momentum between the sea surface and the air.Volume 02See alsoTeleconnection, Heat capacity
Offshore wind farm: A group of wind turbines at sea generating electricity.Volume 04See alsoFloating offshore wind, Decarbonization, Tidal stream turbine
Opus caementicium: Roman hydraulic concrete capable of hardening underwater, used to build durable harbor structures.2.3See alsoTrireme
Outgassing: The release of gases and water vapour from a planet's interior through volcanism.1.1See alsoLate heavy bombardment, Deuterium
Outrigger canoe: A canoe with one or more side floats, used by Austronesian voyagers for stability at sea.Volume 01See alsoWayfinding, Polynesian triangle, Double-hulled canoe
Overtourism: A level of visitor pressure that damages the environmental, social or infrastructural fabric of a destination.B.3See alsoVisitor quota, Social licence to operate, Marine protected area
Oyster reef: A dense, self sustaining structure built up by generations of oysters growing on top of each other's shells.E.3See alsoFilter feeder, Ecosystem engineer

Payment for ecosystem services: Paying people to conserve or restore natural systems that benefit others.Volume 04See alsoBlue carbon credit, Ecosystem services
Pelagic zone: The open water column of the ocean, away from the coast and the seafloor.B.1See alsoEpipelagic zone, Mesopelagic zone, Blue corridor
pH scale: A logarithmic scale measuring acidity or alkalinity, where each whole number change represents a tenfold change in acidity.D.3See alsoOcean acidification, Calcifying organism, Calcification
Photic zone: The sunlit surface layer of the ocean where photosynthesis can occur.A.1See alsoEuphotic, Compensation depth, Epipelagic zone
Phytoplankton: Microscopic, photosynthetic organisms that live near the ocean surface and form the base of most marine food webs.D.2 A.2See alsoDiatom, Bloom, Chlorophyll
Piezophile: An organism adapted to thrive under extremely high pressure.D.1See alsoHadal zone, Ocean trench, Bathypelagic zone
Pirate code: Rules agreed among pirate crews on conduct, discipline and the sharing of plunder.Volume 01See alsoPrivateer, Letter of marque, Buccaneer
Pneumatophore: A specialized root that grows upward out of the mud to take in oxygen for a mangrove tree.C.1See alsoMangrove, Rhizome, Blue carbon
Polyculture: A farming system that grows multiple species together, often at different trophic levels, so that one species' waste becomes another's input.D.4See alsoIntegrated multi trophic aquaculture (IMTA), Aquaculture, Mariculture
Polymetallic nodules: Potato sized mineral concretions found on the deep seafloor, containing cobalt, nickel, manganese and copper.B.5See alsoDeep sea mining
Polynesian triangle: The vast Pacific region bounded by Hawaii, Rapa Nui and Aotearoa, settled by Austronesian-descended voyagers.2.1See alsoWayfinding, Outrigger canoe, Double-hulled canoe
Port state control: Inspection of foreign ships in port to enforce safety and environmental rules.Volume 04See alsoFlag of convenience, Classification society
Portolan chart: A practical medieval and early modern nautical chart showing coastlines and compass bearings.3.3See alsoRhumb line, Compass rose
Prebiotic chemistry: Chemical reactions that could have produced the building blocks of life before biology existed.1.2See alsoChemical evolution, Hydrothermal vent, Stromatolite
Privateer: A privately owned ship authorized by a government to attack enemy shipping.3.6See alsoLetter of marque, Pirate code, Golden Age of Piracy
Pycnocline: A layer where water density rises quickly with depth, resisting vertical mixing.Volume 02See alsoThermocline, Halocline, Stratification

Reef building coral: A category of coral species whose colonies form the hard structural base of a reef.E.1See alsoCoral polyp, Zooxanthellae, Coral atoll
Rhizome: An underground stem that spreads horizontally and anchors seagrass in sediment.C.2See alsoSeagrass, Mangrove, Pneumatophore
Rhumb line: A line on a navigational chart showing a constant compass bearing, used to plot sea routes.3.3See alsoPortolan chart, Compass rose, Marine chronometer
Rip current: A narrow, fast current flowing away from shore, formed by waves and the shape of the seabed.Volume 02See alsoLongshore drift, Estuary
Rogue wave: An unusually large, unpredictable wave that rises far above the surrounding sea.Volume 02See alsoSwell, Fetch

Sakoku: Japan's policy of restricted foreign contact during the Tokugawa period.3.1
Salinity: The amount of dissolved salt in seawater, about 35 grams per kilogram on average.Volume 02See alsoHalocline, Thermohaline circulation
Salt marsh: A coastal wetland dominated by salt tolerant grasses that is regularly flooded by tides.C.3See alsoEstuary, Blue carbon, Tidal flushing
Sea ice: Frozen seawater that forms and melts with the seasons in polar regions.Volume 02See alsoBrine rejection, Albedo effect
Seabed 2030: An international initiative aiming to produce a complete high resolution map of the world's ocean floor by 2030.C.2See alsoMultibeam sonar
Seafloor spreading: The process by which new oceanic crust forms at mid ocean ridges and moves away from the ridge axis over time.B.3See alsoMid-ocean ridge, Wilson cycle, Subduction zone
Seagrass: A group of flowering plants adapted to live fully submerged in shallow marine water.C.2See alsoRhizome, Blue carbon, Nursery habitat
Seamount: An underwater mountain, usually of volcanic origin, that rises at least 1,000 meters from the surrounding seafloor without reaching the surface.B.2See alsoGuyot, Hotspot volcanism, Abyssal hill
Sediment core: A cylindrical sample drilled from the seafloor that preserves layers of sediment in chronological order.B.1See alsoAbyssal plain, Marine snow, Stratification
Small island developing state (SIDS): A group of low lying island and coastal countries that share development challenges including limited institutional capacity relative to very large exclusive economic zones.D.6See alsoBlue economy, Overtourism, Fisheries subsidy
Social licence to operate: The ongoing acceptance of a company's or sector's operations by the local community, public and other stakeholders, beyond formal legal permission.C.4See alsoInstitutional capacity, Just transition, Overtourism
Solubility pump: The physical process by which cold, dense surface water absorbs carbon dioxide and sinks, transporting that carbon to the deep ocean.D.1See alsoBiological pump, Export production, Ocean acidification
Spawning aggregation: A temporary gathering of many fish at one place and time to reproduce.Volume 03See alsoLarval dispersal, Natal homing
Species range shift: A change in where a species lives, often driven by warming water.Volume 03See alsoMarine heatwave, Teleconnection
Spice trade: The historic commerce in Asian spices that drove European exploration and colonization.Volume 01See alsoChartered company, Monsoon trade route
Spillover effect: The movement of fish biomass, larvae or adults from inside a marine protected area into surrounding waters, benefiting nearby fisheries.D.3See alsoMarine protected area, Ecosystem connectivity, Larval dispersal
Spring tide: A tide of unusually large range that occurs when the Sun, Earth and Moon are aligned, reinforcing the gravitational pull.A.2See alsoTidal range, Tidal flushing
Star compass: A traditional navigation method using the rising and setting points of stars to hold a steady course.Volume 01See alsoWayfinding, Sunstone, Rhumb line
Storm surge: An abnormal rise of seawater pushed onshore by a storm's winds and low pressure.Volume 02See alsoTropical cyclone, Latent heat
Stranded asset: An investment that loses value before the end of its expected life because of changing regulation, markets or technology.B.2See alsoDivestment, Decarbonization, Just transition
Stratification: The layering of ocean water by density, which can reduce the mixing of oxygen and nutrients between surface and deep layers.D.4See alsoThermocline, Pycnocline, Halocline
Stromatolite: A layered rock structure built by ancient microbial mats, among the oldest direct fossil evidence of life.Volume 01See alsoCyanobacteria, Great Oxidation Event
Subduction zone: A region where one tectonic plate sinks beneath another, often producing deep ocean trenches.1.4 B.4See alsoMid-ocean ridge, Wilson cycle, Ocean trench
Submarine cable: A cable on the seafloor carrying data or electricity; such cables carry about 99% of intercontinental internet traffic.Volume 04See alsoTransatlantic telegraph cable
Sunstone: A crystal, possibly calcite, theorized to have helped Viking sailors locate the sun under cloud cover.2.5See alsoWayfinding, Star compass
Sustainable seafood certification: A label showing seafood was caught or farmed with responsible practices.Volume 04See alsoMaximum sustainable yield, Aquaculture
Swell: Organized, long period waves that have travelled beyond the storm that generated them, keeping their shape over great distances.A.1See alsoFetch, Rogue wave, Internal wave
Symbiosis: A close biological relationship between two different species, such as tube worms hosting chemosynthetic bacteria.D.2See alsoZooxanthellae, Symbiotic bacteria, Chemosynthesis
Symbiotic bacteria: Bacteria living inside or on another organism, here converting chemical energy into food for their host.D.3See alsoChemosynthesis, Hydrothermal vent, Symbiosis

Teleconnection: A link between weather or climate anomalies in distant parts of the world, often driven by patterns like ENSO.C.4See alsoOcean-atmosphere coupling, Species range shift
Terrestrialization: The evolutionary process by which aquatic organisms adapted to live on land.1.5See alsoCambrian explosion, Food web
Thermocline: A layer where temperature drops quickly with depth, separating warm surface water from cold deep water.Volume 02See alsoPycnocline, Stratification, Halocline
Thermohaline circulation: Deep ocean circulation driven by differences in water density caused by temperature and salinity, rather than by wind.C.2See alsoAMOC, Deep water formation, Salinity
Tidal flushing: The repeated exchange of water between a marsh and the sea driven by the tidal cycle.C.3See alsoEstuary, Salt marsh, Spring tide
Tidal range: The vertical difference in sea level between high tide and low tide at a given location.A.2See alsoSpring tide, Tidal flushing
Tidal stream turbine: An underwater turbine that generates electricity from the kinetic energy of tidal currents, similar in principle to a wind turbine.D.1See alsoOffshore wind farm, Floating offshore wind
Tradable share: A unit of company ownership that can be bought and sold, pioneered at scale by the VOC.4.1
Trade winds: Persistent easterly winds near the equator that normally push warm surface water toward the western Pacific.C.4See alsoMonsoon, Monsoon trade route, Coriolis effect
Trading post: A fortified settlement set up by a chartered company to control overseas commerce.Volume 01See alsoChartered company, Joint-stock company
Tragedy of the commons: The tendency for a shared resource with no clear ownership to be overused because no single user bears the full cost of depletion.A.2See alsoExternality, Natural capital, Maximum sustainable yield
Transatlantic telegraph cable: An undersea cable, first working in 1858 and reliably from 1866, that linked Europe and North America.Volume 01See alsoSubmarine cable, Containerization, Coaling station
Treasure fleet: The large Ming dynasty naval expeditions led by Admiral Zheng He between 1405 and 1433.3.1See alsoChartered company
Triangular trade: The three-legged Atlantic trading system linking Europe, Africa and the Americas.3.5See alsoMiddle Passage
Trireme: A fast ancient Greek warship powered by three rows of oarsmen.2.3
Trophic cascade: A chain reaction of ecological change that spreads through a food web after a key species is lost or added.E.4See alsoKeystone species, Apex predator, Food web
Trophic level: An organism's position in a food web, based on what it eats and what eats it.Volume 03See alsoFood web, Apex predator
Tropical cyclone: An intense rotating storm over warm tropical water, called a hurricane or typhoon by region.Volume 02See alsoStorm surge, Monsoon, Latent heat
Twenty-foot equivalent unit (TEU): The standard measure of cargo capacity, based on one twenty foot container.Volume 04See alsoContainerization, Intermodal transport

Ultra deepwater drilling: Oil and gas extraction at water depths beyond about 1,500 metres, requiring specialised floating platforms and remote operated equipment.B.2
Upwelling: The rising of cold, nutrient rich water from depth toward the surface, often triggered by currents, wind or seafloor topography.B.2See alsoNutrient cycling, Export production
Urchin barren: A seafloor area stripped of kelp by overgrazing sea urchins, usually after predator loss.C.4See alsoKelp forest, Holdfast, Trophic cascade

Visitor quota: A cap on the number of people permitted to access a site in a given period, used to limit ecological or crowding pressure.D.5See alsoOvertourism, Social licence to operate

Wayfinding: A traditional navigation method using natural signs such as stars, swells and wildlife instead of instruments.2.1See alsoStar compass, Sunstone, Outrigger canoe
Western boundary current: A fast, narrow, warm current on the western edge of an ocean basin, such as the Gulf Stream.Volume 02See alsoGyre, Coriolis effect
Whale fall: The carcass of a dead whale that sinks to the seafloor and supports a long lived community of organisms.B.2See alsoWhale pump, Chemosynthesis
Whale pump: The process by which whale feces fertilize surface water with nutrients from deeper feeding grounds.B.2See alsoWhale fall, Krill, Nutrient cycling
Wilson cycle: The repeated process by which ocean basins open through rifting and later close through subduction.Volume 01See alsoMid-ocean ridge, Subduction zone, Seafloor spreading

Zooxanthellae: Microscopic algae that live inside coral tissue and provide it with food through photosynthesis.E.1See alsoCoral polyp, Symbiosis, Reef building coral

Index of names

People, places, ships and institutions mentioned in the subsections. Numbers link to each mention.

AdenA port city at the mouth of the Red Sea, a historic hub on Indian Ocean monsoon trade routes.2.4
Admiral Yi Sun-sinA Korean naval commander famed for defeating Japanese invasion fleets using armored turtle ships.3.1
Admiral Zheng HeA Ming dynasty Chinese admiral who led massive treasure fleet voyages across the Indian Ocean.3.1
AfricaThe continent bordered by the Atlantic and Indian Oceans, central to early trade routes and the triangular trade.3.2 3.5 C.3 C.4
AfricanRelating to Africa, its peoples and coasts, referenced across Indian Ocean and Atlantic trade history.2.4 3.2 3.5
AfricansPeople of Africa, millions of whom were forcibly transported across the Atlantic during the triangular trade.3.5
AlexandriaAn ancient Egyptian port city famed for its lighthouse and library, a hub of early maritime knowledge.2.2 2.3
AlvinA deep sea research submersible used to explore hydrothermal vents and other ocean floor features.D.2
AmazonThe world's largest river basin, often compared with the ocean in oxygen and carbon cycling.D.2 A.2
AmericaA continent reached by Norse voyagers and later central to Atlantic trade and ENSO climate patterns.2.5 C.4
AmericasThe continents reached by European voyages after 1492, central to colonial trade networks.3.2 3.5
AmsterdamA Dutch port city that became the financial capital of early multinational trading companies.3.4 4.1
Ancient WorldThe period of early Mediterranean and Near Eastern civilizations, including Egypt's maritime achievements.2.2
Anne BonnyAn Irish-born pirate who sailed the Caribbean during the early eighteenth century Golden Age of Piracy.3.6
AntarcticThe southern polar ocean region, important for deep water formation and conservation.D.6
AotearoaThe Maori name for New Zealand, one of the farthest points reached by Austronesian voyagers.2.1
ArabRelating to Arab traders and navigators who linked the Indian Ocean, Mediterranean and East Africa.2.4 3.3
ArabiaThe peninsula whose coasts and merchants connected East Asia to Indian Ocean trade networks.3.1
ArcticThe northern polar ocean, discussed for tipping points, warming and sea ice loss.C.3 D.6
AsiaThe continent central to Austronesian expansion, Indian Ocean trade and early European voyages east.2.1 2.4 3.1 3.2 C.3
AtlanticThe ocean basin central to Viking voyages, European exploration, the triangular trade and major currents.2.5 3.2 3.4 3.5 3.6 A.1 A.3 B.1 C.2 C.4 A.2 D.6
Atlantic CurrentA surface current system carrying warm water northward across the Atlantic Ocean.A.3
Atlantic Meridional Overturning CirculationA major system of ocean currents, including the Gulf Stream, that moves heat northward in the Atlantic.C.2 C.3
Atlantic OceanThe ocean basin that opened as Pangaea broke apart, now shaped by plate tectonics.1.4
AustraliaA continent whose ancient rocks preserve early oxygenation evidence and whose reefs face climate stress.1.3 C.4 E.1
AustronesianRelating to seafaring peoples who expanded from Taiwan across the Pacific more than 3,000 years ago.2.1

BalticA northern European sea that Viking seafarers used as a route for trade and raiding.2.5
BataviaThe Dutch East India Company's colonial headquarters, now Jakarta, in the East Indies.4.1
Battle of HimeraAn ancient battle between Carthage and Greek city-states in Sicily, in 480 BCE.2.3
Biodiversity Beyond National JurisdictionAn international framework and treaty governing marine life in waters beyond national control.C.1
Black SeaA sea connected to the Mediterranean, linked to Viking river routes and ancient trade.3.3
BristolAn English port city important in Atlantic trade, including the slave trade, and early steam shipping.4.2
Burgess ShaleA fossil deposit in Canada preserving exceptionally detailed soft-bodied Cambrian animals.1.5

Cabo PulmoA Mexican marine protected area known for dramatic fish recovery after protection.D.3
CadizA Spanish port city central to voyages of exploration and Atlantic trade.3.2 3.5
CaesareaAn ancient Roman port city on the Mediterranean coast built with advanced harbor engineering.2.3
Calico Jack RackhamAn English pirate captain active in the Caribbean during the Golden Age of Piracy.3.6
CalicutAn Indian port city, a key stop on Indian Ocean trade routes and early European voyages.2.4 3.1
CaliforniaA US Pacific coast state known for upwelling currents, seamounts and kelp forests.A.3 B.2 B.1 C.4
CambrianThe geological period, beginning about 540 million years ago, marked by rapid animal diversification.1.5
CanadaA North American country whose fossil sites and Atlantic waters feature in ocean history and ecology.1.5
Canadian RockiesA mountain range in Canada home to the fossil-rich Burgess Shale.1.5
Cape of Good HopeThe southern tip of Africa rounded by Portuguese navigators seeking a sea route to Asia.3.2
CaribbeanA sea region central to piracy, colonial trade and modern reef conservation.3.4 3.5 3.6 A.3 D.6
Carta PisanaOne of the oldest surviving portolan charts, a navigational map from medieval Italy.3.3
CarthageAn ancient North African maritime power and trading rival of Greece and Rome.2.3
CastileA medieval Spanish kingdom that sponsored early transoceanic voyages of exploration.3.2
Census of Marine Life synthesisA major scientific effort that compiled global data on ocean biodiversity.A.3
Challenger DeepThe deepest known point in the ocean, in the Mariana Trench.B.4 D.1
Chesapeake BayA large US estuary known for its oyster reefs, salt marshes and low-oxygen summers.C.3 E.3
ChinaAn East Asian nation historically linked to treasure fleets and today a major shipbuilding power.3.1 B.1
Christopher ColumbusA Genoese navigator whose 1492 voyage opened sustained contact between Europe and the Americas.3.2
Clarion Clipperton ZoneA vast Pacific seafloor region rich in polymetallic nodules targeted for deep sea mining.B.5
Convention on Biological DiversityAn international treaty to conserve biodiversity, including marine protected area targets.D.3
CoriolisShort for the Coriolis effect, which deflects moving water and air because Earth rotates.A.3

Deep Sea Conservation CoalitionAn alliance of organizations advocating protection of deep sea ecosystems.C.4
DublinAn Irish port city founded by Viking settlers.2.5
Dutch East India CompanyA powerful seventeenth century Dutch trading company, often cited as the first multinational corporation.3.4 4.1
Dutch RepublicA seventeenth century maritime and trading power that built a global commercial empire.3.4 3.6

East AfricaThe eastern African coast, a historic hub of Indian Ocean trade and community mangrove projects.3.1 D.6
East AsiaThe region including China, Japan and Korea, with a long maritime and naval history.D.6
East India CompanyA British chartered trading company that dominated commerce between Europe and Asia.4.1
East IndiesA historical term for the islands of Southeast Asia, a major target of European trading companies.3.4 4.1
Easter IslandA remote Pacific island settled by Austronesian voyagers, known as Rapa Nui.2.1
EcuadorA South American country whose coastal waters are strongly affected by El Nino.C.4
EgyptAn ancient civilization along the Nile that developed some of the earliest navigation knowledge.2.2
EgyptiansThe ancient people of Egypt, early builders of river and sea going ships.2.2
El NinoThe warm phase of the El Nino Southern Oscillation, altering Pacific temperatures and global weather.C.4
El Nino Southern OscillationA recurring climate pattern of warm and cool phases in the tropical Pacific.C.4
Emory UniversityA US university that hosts the Slave Voyages research database.3.5
Encyclopaedia BritannicaA general reference encyclopedia cited for historical maritime facts.2.3 3.3
EnglandA European kingdom whose merchants and navy built major overseas trading companies and routes.3.4
ENSOAbbreviation for the El Nino Southern Oscillation, a major driver of global climate variability.C.4
EuropeThe continent whose explorers, companies and industries shaped much of global maritime history.2.4 2.5 3.1 3.3 3.5 4.1 A.3 C.2 C.4 C.3
European Commission Joint Research CentreA European Union scientific body cited for research on coastal erosion.A.4

FAOThe Food and Agriculture Organization of the United Nations, which reports on world fisheries and aquaculture.C.1 E.5 A.2 B.4 D.4 D.6
Ferdinand MagellanA Portuguese navigator whose expedition achieved the first circumnavigation of the globe.3.2
FijiA Pacific island nation where tourism supports marine conservation.D.5
FranceA European power that built colonial trading companies and took part in the triangular trade.3.4 4.1
Francis DrakeAn English privateer and explorer known for raiding Spanish shipping and sailing around the globe.3.6

Galapagos IslandsA Pacific island group near where hydrothermal vents were first discovered in 1977.D.2
Galapagos RiftAn undersea spreading ridge near the Galapagos Islands where hydrothermal vents were first found.D.2
GalileoAn Italian scientist whose work belongs to the age of science, empire and cartography.3.3
GCRMNThe Global Coral Reef Monitoring Network, which tracks reef health worldwide.C.3
GEBCOThe General Bathymetric Chart of the Oceans, a project mapping the global seafloor.C.2
GenoaAn Italian maritime republic known for navigation, cartography and trade in the medieval era.3.3
Global Carbon BudgetAn annual scientific assessment of sources and sinks of carbon dioxide.D.1
Global Carbon ProjectA research initiative that compiles data on the global carbon cycle.D.1
Global Coral Reef Monitoring NetworkA worldwide scientific network that monitors coral reef condition.C.3
Global Fossil Fuel Divestment Commitments DatabaseA tracker of institutional pledges to withdraw investment from fossil fuels.C.4
Grand BanksA fishing region off Newfoundland famous for its collapsed cod fishery.A.2
Great Barrier ReefThe world's largest coral reef system, off Australia, facing repeated bleaching events.E.1 E.2 C.3
Great OxidationShort for the Great Oxidation Event, when atmospheric oxygen rose sharply about 2.4 billion years ago.1.3
GreeceAn ancient Mediterranean civilization whose city-states built major maritime trade and naval power.2.2
GreenlandA large Arctic island reached and partly settled by Norse voyagers.2.5

Hamersley BasinAn Australian geological region where banded iron formations record early ocean oxygenation.1.3
HavanaA Caribbean port city that gathered Spanish treasure fleets and drew pirates and privateers.3.6
HawaiiA central Pacific island chain settled by Polynesian voyagers.2.1 B.5
Henry MorganA Welsh privateer who led major raids against Spanish colonies in the Caribbean.3.6
High Seas TreatyAn international agreement to protect biodiversity in waters beyond national jurisdiction.C.1 D.3
HoustonA major US port tied to the growth of container shipping.4.3
Hurricane KatrinaA devastating 2005 Atlantic hurricane that struck the US Gulf Coast.C.3
HywindThe world's first commercial floating offshore wind farm, off Scotland.D.1

IcelandA North Atlantic island settled by Norse voyagers, sitting on the Mid-Atlantic Ridge.2.5 A.1 B.3
IEAThe International Energy Agency, which reports on global energy, including offshore wind.D.1
Imjin WarA late sixteenth century war between Japan and Korea that featured major naval battles.3.1
IMTAIntegrated multi trophic aquaculture, farming several species together so one's waste feeds another.D.4
IndiaA South Asian nation whose coasts were central to Indian Ocean trade and European voyages.2.4 3.1 3.2
Indian OceanThe ocean basin linking Africa, Arabia and Asia through ancient monsoon trade routes.2.4 3.1 3.4 A.3 D.6
IndonesiaA Southeast Asian archipelago nation central to the spice trade and affected by El Nino.4.1 C.4 B.1
Intergovernmental Panel on Climate ChangeThe United Nations body that assesses scientific evidence on climate change.C.1 D.1 D.4
International Cable Protection CommitteeAn organization focused on protecting undersea telecommunications cables.B.5
International Energy AgencyAn intergovernmental organization analyzing global energy markets, including offshore energy.B.2 D.1
International Institute of Social HistoryA research institute whose archives document early trading companies.3.4 4.1
International Maritime OrganizationThe United Nations agency for shipping safety and environmental rules.4.2 B.1
International Seabed AuthorityThe body that regulates mineral activities on the international seabed.B.5
IPBESThe Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services.E.4
IPCCThe Intergovernmental Panel on Climate Change, which assesses global climate science.E.4
IRENAThe International Renewable Energy Agency, which tracks renewable energy including marine sources.B.5 D.1
Island Southeast AsiaThe archipelago region from which Austronesian seafarers launched their Pacific expansion.2.1
IUCNThe International Union for Conservation of Nature, which assesses species and ecosystem status.B.1 B.2 B.3 C.4 E.1 E.2 E.3 C.1

Jack HillsAn Australian rock formation holding crystals that suggest liquid water about 4.4 billion years ago.1.1
JapanAn East Asian island nation with a long maritime history and a major shipbuilding industry.3.1 B.1
Joan Blaeu's Atlas MaiorA seventeenth century Dutch atlas regarded as a masterwork of cartography.3.3
Juan Sebastian ElcanoA Basque navigator who completed the first circumnavigation after Magellan's death.3.2

KenyaAn East African nation known for community mangrove and blue carbon projects.A.3
Kenya's Gazi BayA coastal site in Kenya where a pioneering mangrove blue carbon project operates.D.2
KievA city on Viking river routes linking Scandinavia to the Black Sea.2.5
KilwaA historic Swahili trading city important in Indian Ocean commerce.2.4
KoreaAn East Asian nation with historic naval wars against Japan and a large modern shipbuilding industry.3.1
Kunming Montreal Global Biodiversity FrameworkA 2022 global agreement with a target to protect 30 percent of land and sea by 2030.D.3

L'AnseShort for L'Anse aux Meadows, a confirmed Norse settlement in Newfoundland, about 1000 CE.2.5
La NinaThe cool phase of the El Nino Southern Oscillation, affecting global weather.C.4
Library of CongressThe US national library, holder of major historic map collections.3.1 3.2 3.3
Lighthouse of AlexandriaAn ancient wonder built to guide ships into the harbor of Alexandria, Egypt.2.2
LisbonThe Portuguese capital and a major departure point in the age of exploration.3.5
LiverpoolAn English port city that profited heavily from the transatlantic slave trade.3.5
Lloyd's Coffee HouseA seventeenth century London coffee house where modern marine insurance began.3.4
Lloyd's of LondonA London insurance market that grew out of marine insurance for shipping.3.6
Locally Managed Marine Area NetworkA network supporting community based ocean management.D.5
LondonThe English capital and a major historic center of maritime trade and insurance.3.4
LorientA French port founded for the French East India Company.3.4

MadagascarA large island off East Africa reached by Austronesian voyagers long before European contact.2.1
MaerskA major Danish shipping company, early in container shipping and in lower carbon fuels.B.1
MalaccaA historic Southeast Asian port city controlling a key trade strait.2.4 3.1
Malcom McLeanAn American trucking entrepreneur credited with pioneering modern container shipping in 1956.4.3
MalindiA historic East African port where Vasco da Gama found a pilot for India.3.1
MallorcaA Mediterranean island known for its medieval school of nautical cartography.3.3
Mare NostrumLatin for "our sea", the Roman name for the Mediterranean.2.3
Mariana TrenchThe deepest oceanic trench on Earth, containing the Challenger Deep.B.4 D.1
Mary ReadAn English pirate who sailed the Caribbean during the Golden Age of Piracy.3.6
MediterraneanA sea bordered by Europe, Africa and Asia, central to ancient trade, war and navigation.2.2 2.3 2.4 3.3 E.5 D.6
MeijiA late nineteenth century Japanese era of rapid modernization, including naval reform.3.1
MexicoA North American nation with Pacific marine protected areas and Gulf oil and gas.D.3 B.5 D.3
Mid-Atlantic RidgeThe undersea mountain chain where the Atlantic seafloor spreads apart.1.4
Mikoko PamojaA community mangrove project in Kenya that sells verified blue carbon credits.D.2
MingThe Chinese dynasty that sponsored Zheng He's treasure fleet voyages.3.1
Mississippi RiverA major US river whose nutrient runoff feeds the Gulf of Mexico dead zone.D.4
MogadishuA historic East African port important to medieval Indian Ocean trade.2.4
Monterey CanyonAn undersea canyon off California where deep sea life and whale falls are studied.B.2

NantesA French port city that led France's part in the Atlantic slave trade.3.5
Napoleon BonaparteA French military and political leader of the early nineteenth century.3.4
NASAThe US space agency, a source on early Earth oceans and satellite ocean data.1.2 D.2
NassauA Caribbean port that served as a notorious pirate base in the early eighteenth century.3.6
National Geographic SocietyAn organization promoting exploration and education, cited for ocean history.2.2
National Maritime MuseumA UK museum in Greenwich documenting exploration and seafaring.3.2
National Museum of DenmarkA Danish museum with major Viking ship collections.2.5
NatureA leading scientific journal.A.4
Nature GeoscienceA scientific journal cited for research on early Earth's water.1.1
Nauru AgreementA Pacific island fisheries agreement managing tuna across member nations.D.6
NetherlandsA European nation whose trading companies and capital markets shaped early globalization.3.4
New YorkA major US port city.4.2
NewarkA US port where the first container ship voyage departed in 1956.4.3
NewfoundlandA Canadian island reached by Norse voyagers and site of the collapsed Grand Banks cod fishery.2.5 A.2
NileThe Egyptian river whose seasonal flooding shaped early navigation and farming.2.2
Nippon FoundationA Japanese foundation that funds the Seabed 2030 global ocean mapping project.C.2
NOAAThe US National Oceanic and Atmospheric Administration, a key source on ocean science.D.1 A.1 A.3 C.2 D.1 D.2 D.3
NOAA Coral Reef WatchA NOAA program that monitors coral reefs for bleaching risk worldwide.E.2
NOAA FisheriesThe NOAA agency that manages US marine fisheries and protected species.B.1 E.3 D.4
NOAA National Hurricane CenterThe NOAA center that tracks and forecasts tropical storms and hurricanes.C.3
NOAA Ocean ExplorationA NOAA program exploring largely unknown parts of the ocean.1.5 B.2 B.3 D.1 D.2 D.3
NorseRelating to the Scandinavian peoples of the Viking age who voyaged across the North Atlantic.2.5
Northern HemisphereThe half of Earth north of the equator, where currents are deflected to the right.A.3
NorwayA Scandinavian nation central to Viking history and modern floating offshore wind.2.5 A.3 B.2
Nova ScotiaA Canadian province on the Bay of Fundy, home of the world's largest tides.A.2

OECDThe Organisation for Economic Co-operation and Development, a source of ocean economy statistics.A.1 B.3
OrmuzA historic port and strait controlling access between the Persian Gulf and the Indian Ocean.2.4
OstiaThe ancient port of Rome, central to Mediterranean grain shipping.2.3

PacificThe world's largest ocean, central to Austronesian voyaging and ENSO.2.1 A.1 A.3 B.1 C.1 C.4 B.1 E.4 E.5 B.5 D.6
Pacific NorthwestA North American coastal region where ocean acidification hit oyster hatcheries.D.3
PangaeaThe ancient supercontinent that began breaking apart about 200 million years ago, opening the Atlantic.1.4
Persian GulfA Middle Eastern sea long central to trade and today a major oil and gas basin.2.4 B.2
PeruA South American nation off whose coast El Nino was first named by fishers.C.4
PharosThe island and lighthouse of Alexandria, one of the Seven Wonders of the ancient world.2.2
PhilippinesA Southeast Asian archipelago reached during Magellan's voyage, where he was killed in 1521.3.2
PhoeniciansAncient Mediterranean seafarers known for pioneering long distance maritime trade.2.3
PilbaraAn Australian region holding some of the oldest known evidence of microbial life.1.2
PiraeusThe port of Athens, central to Greek naval and trading power.2.3
PolynesianRelating to the Pacific peoples descended from Austronesian voyagers who settled remote islands.2.1
Port RoyalA Jamaican port once notorious as a base for pirates and privateers.3.6
PortugueseRelating to Portugal, a pioneer of transoceanic exploration and the sea route to India.2.4 3.2 3.6

Rapa NuiThe Polynesian name for Easter Island.2.1
RAPIDA long running ocean observing array that measures the strength of the AMOC.C.2
Red SeaA sea between Africa and Arabia important to ancient Egyptian and Indian Ocean trade.2.2
RomeThe ancient capital whose empire dominated Mediterranean trade, war and engineering.2.3
RotterdamEurope's largest port and a hub for container shipping.4.3 B.1
Royal Museums GreenwichA UK museum group documenting maritime exploration and naval history.3.2 3.6 4.2

SagresA Portuguese coastal site linked to Prince Henry and early navigation.3.2
SamoaA Pacific island nation settled during the Austronesian expansion.2.1
Sargasso SeaA clear, nutrient poor region of the North Atlantic defined by floating seaweed.A.1
ScotlandA UK nation home to the first commercial floating offshore wind farm.D.1
SevilleThe Spanish city that controlled trade with the Americas in the sixteenth century.3.2
ShanghaiThe world's busiest container port.4.3 B.1
SicilyA Mediterranean island fought over by Greeks, Carthaginians and Romans.2.3
SidonAn ancient Phoenician city known for maritime trade and craftsmanship.2.3
SingaporeA major Southeast Asian port and global shipping hub.4.3 B.1
Slave VoyagesA research database documenting transatlantic and intra-American slave trade voyages.3.5
Smithsonian InstitutionA US museum and research complex cited on ocean and evolutionary history.1.2 1.5 2.1
SofalaA historic East African port linked to the gold trade of the Indian Ocean.2.4
SOLASThe International Convention for the Safety of Life at Sea, first adopted after the Titanic sank.4.2
South AmericaA continent whose western coast is strongly affected by El Nino and La Nina.C.4
South KoreaAn East Asian nation and leading center of commercial shipbuilding.B.1
Southeast AsiaA region of islands and straits central to the spice trade and maritime routes.C.4
Southern HemisphereThe half of Earth south of the equator, where currents are deflected to the left.A.3
SpainA European kingdom that sponsored early transoceanic voyages including Magellan's.3.2
Spice IslandsThe Maluku islands of Indonesia, prized for cloves and nutmeg.3.2
Strait of MagellanA sea passage at South America's southern tip, first crossed by Magellan in 1520.3.2
Strait of MalaccaA narrow Southeast Asian passage that remains one of the busiest shipping routes on Earth.2.4
SwahiliA coastal East African culture shaped by centuries of Indian Ocean trade.2.4

TaiwanAn East Asian island considered the starting point of the Austronesian expansion.2.1
ThamesThe river through London, tied to England's maritime trade.3.4
The National ArchivesThe UK government archive holding records on trading companies and colonial history.3.4 4.1
ThermopylaeAn ancient Greek battle site of 480 BCE, fought alongside the naval battle of Artemisium.2.3
Thingvellir National ParkAn Icelandic park where the Mid-Atlantic Ridge can be seen on land.B.3
TitanicAn ocean liner that sank in 1912, prompting major maritime safety reforms.4.2
TokugawaThe Japanese shogunate that limited foreign sea contact for over two centuries.3.1
TriesteA bathyscaphe that made the first crewed descent to the Challenger Deep in 1960.D.1
TyreAn ancient Phoenician city renowned for seafaring, trade and purple dye.2.3

UNCTADThe United Nations Conference on Trade and Development, a source on shipping and trade data.2.4 4.3 A.3 B.1 D.2
UNEPThe United Nations Environment Programme, a source on blue carbon and marine ecosystems.A.2 C.1 C.2 C.3 E.5 D.2
UNESCOThe United Nations body for education, science and culture, which coordinates ocean science.2.1 2.2 3.1 3.5
UNESCO Intergovernmental Oceanographic CommissionA UNESCO body coordinating international ocean science and observation.D.4 C.3
United KingdomA European nation with a long history in shipping, offshore oil, gas and wind.B.2
United NationsThe international organization behind major ocean treaties.A.3 C.1
United StatesA North American nation with Pacific and Atlantic coasts and major ocean science agencies.C.4
US Geological SurveyA US federal science agency studying geology, plate tectonics and earthquakes.1.1 1.3 1.4 2.3
USGSAbbreviation for the United States Geological Survey.1.4

Vasco da GamaA Portuguese navigator who opened the first direct European sea route to India in 1498.2.4 3.2
VeniceAn Italian maritime republic that became a center of trade and cartography.3.3
VictoriaThe only ship of Magellan's fleet to complete the first circumnavigation, in 1522.3.2
VietnamA Southeast Asian nation with large mangrove forests.C.1
VikingRelating to Norse seafarers who raided, traded and settled across the North Atlantic.2.5
VOCAbbreviation for the Dutch East India Company.4.1

West AfricaThe western African coast, tied to the transatlantic slave trade and modern offshore oil.B.2
Western AustraliaAn Australian region with some of the oldest rocks on Earth and the vast Shark Bay seagrass.1.1 1.2 C.2
Woods Hole Oceanographic InstitutionA leading US ocean research institution.A.3
World BankAn international financial institution that reports on coastal and ocean economies.B.3
World Meteorological OrganizationThe United Nations agency for weather, climate and water.A.1
World Resources InstituteA research organization that reports on reefs and natural capital.A.2
WWFThe World Wide Fund for Nature, a conservation organization.A.1

Zheng HeA Ming dynasty Chinese admiral who commanded treasure fleets across the Indian Ocean, 1405 to 1433.3.1