Ecoregion
Connect carbonate production with marine life
Use the reef as an example alongside CFD B7–B10; distinguish living structures from the later dissolution and burial pathways.
Ocean Literacy Principle 2
The ocean and life in the ocean shape Earth
Follow matter through the atmosphere, hydrosphere, biosphere, and lithosphere. Connect the rock cycle and plate tectonics with ocean carbon, phosphorus, nitrogen, and silica cycles.
Guiding question: How do ocean processes and marine organisms cycle matter and build or transform Earth materials?
NMEA grade band: Grades 9–12
Other grade bands are in preparation.
At a glance
What students should take away
Trace matter between Earth’s reservoirs, distinguish recycling from long-term storage, and explain how marine life and human activities alter these pathways.
Learning goals
- Explain how weathering, subduction, sedimentation, accretion, and volcanism connect ocean and land.
- Distinguish organic and inorganic carbon pathways, including carbonate formation and fossil fuels.
- Compare phosphorus and nitrogen uptake, regeneration, burial, and human inputs.
- Explain how silica structures can dissolve or enter the sedimentary record.
Teach this principle
Why this matters
The CFD connects geology and biology through the movement and transformation of matter. Students can compare rapid recycling in seawater and food webs with slower burial, rock formation, uplift, and weathering.
Trace a rock-cycle pathway
- Student task
- Use CFD branch A and the ocean-features map to draw a route from weathered continental rock to ocean sediment, subduction or accretion, and uplift. Label each process.
- Ask the class
- How is sedimentation different from subduction or accretion?
- Listen for
- Settling and transport redistribute sediment; subduction recycles lithosphere, while accretion adds material to a plate.
Compare two carbon pathways
- Student task
- Use CFD B2–B11 to trace organic carbon through biomass and respiration, then inorganic carbon through a shell, dissolution or burial, and rock formation.
- Ask the class
- Which pathways recycle carbon quickly, and which can store it for longer?
- Listen for
- Respiration and dissolution return carbon to inorganic pools; some carbon is buried in rocks or fossil fuels. Burning fossil fuels returns carbon dioxide to the atmosphere.
Teaching resources
Follow phosphorus through a food web
- Student task
- Use CFD B12–B18 to connect rock weathering, dissolved phosphorus, producers, consumers, regeneration, upwelling, and burial. Add a fertilizer or wastewater input.
- Ask the class
- Why does an essential nutrient become a problem when its supply increases too much?
- Listen for
- Phosphorus supports growth, but excess inputs can drive eutrophication and change food webs; some phosphorus takes the slower sedimentary route.
Teaching resources
Identify transformations in the nitrogen cycle
- Student task
- Use CFD B19–B25 to explain why atmospheric nitrogen needs transformation before most organisms can use it. Compare this cycle with phosphorus.
- Ask the class
- What role do nitrogen-fixing microorganisms play?
- Listen for
- They make nitrogen available to biological pathways. Nitrogen changes chemical form, cycles through food webs, and can be buried or added by human activities.
Teaching resources
Connect microscopic structures to rocks
- Student task
- Use CFD B26–B32 to trace silica from weathering into a diatom or sponge, then compare dissolution with burial. Add the route that exposes rock on land again.
- Ask the class
- Does every silica skeleton become a rock?
- Listen for
- Most biogenic silica dissolves; a smaller fraction enters sediments and sedimentary materials. Upwelling, uplift, and weathering reconnect different parts of the cycle.
Teaching resources
Check understanding
Trace one element from a land source into ocean life, then into a sedimentary rock and back toward the ocean. Identify a shorter recycling route and a human influence on the cycle.
Explore the concepts
Rock cycle and plate tectonicsWeathering, erosion, sedimentation, accretion, and volcanism connect land and ocean.
Rocks break down and materials move to the ocean.
Weathering and erosion break down rocks; rivers and atmospheric deposition carry many of the products into the ocean. Materials remain there for different lengths of time, called residence times. Rock breakdown, formation, subduction, and uplift are parts of a continuing cycle.
Subduction reshapes plate boundaries.
Denser oceanic plates can descend beneath continental plates. Subduction can uplift continental margins and add scraped-off oceanic rocks and sediments to them. Trenches, island arcs, stratovolcanoes, and some mountain ranges are associated with subduction; subduction boundaries are prominent around the Pacific Rim.
Some oceanic rocks and sediments travel into the upper mantle with a subducting plate; other material is scraped off and added to the continental margin. These are different destinations within the rock cycle.
Sedimentation, accretion, and volcanism form new rocks.
Sedimentation includes particles settling under gravity and material moved along the seafloor by currents or waves. Accretion adds material to a tectonic plate. Along with uplift, sea-level change, and wave action, these processes reorganize Earth materials. Volcanism at plate boundaries and within plates forms new rock through igneous processes.
Uplift and erosion can expose both igneous and sedimentary rocks. Exposure reveals existing material; volcanism forms new igneous rock by cooling magma or lava.
Connected concepts in other principles
Carbon cycleTrace rapidly recycled carbon alongside the longer routes through sediments, rocks, and fossil fuels.
The ocean connects Earth’s chemical reservoirs.
Matter cycles through the atmosphere, hydrosphere, biosphere, and lithosphere. The ocean plays a major role in cycles essential to life. Seawater contains elements at different concentrations, including carbon, phosphorus, nitrogen, sulfur, oxygen, iron, zinc, calcium, sodium, and potassium; some organisms also require silicon or strontium.
Carbon moves between inorganic and organic forms.
The ocean is the largest reservoir of rapidly cycling organic and inorganic carbon. Atmospheric carbon dioxide enters through diffusion, mixing, and bubble entrainment. Carbon occurs in dissolved inorganic forms such as carbon dioxide, bicarbonate, and carbonate; in organic compounds such as carbohydrates, lipids, and amino acids; and in particles, including living and dead organisms. Photosynthesis and chemosynthesis turn inorganic carbon into organic matter; respiration returns much of it to inorganic forms. Some organic carbon sinks, accumulates, and may eventually become fossil fuel.
Mixing includes convection when density differences cause water to overturn, exchanging dissolved materials between layers.
Carbonate shells connect life with the rock cycle.
Corals and other organisms use dissolved inorganic carbon to form calcium carbonate shells and skeletons. Much of this carbonate dissolves in deep water; some accumulates in limestone, chalk, and carbonate banks. Uplift, accretion, and sea-level changes can expose marine sedimentary rocks on land, where weathering and erosion return material toward the ocean. Burning fossil fuels releases carbon dioxide to the atmosphere, affecting climate and ocean pH.
Both organic-carbon-bearing sediments and inorganic carbonate sediments can enter long geological pathways involving burial, rock formation, uplift and exposure. Weathering and erosion return material to active carbon cycling; oxidation of exposed organic carbon can return carbon dioxide. This geological return is distinct from human combustion of fossil fuels.
Connected concepts in other principles
Phosphorus cycleFollow phosphorus from weathered rocks through organisms, seawater, and sediments.
Phosphorus supports essential cellular compounds.
All life needs phosphorus for compounds such as ATP, DNA, and phospholipids. Weathering of rocks on land is its main ocean source. Phosphorus occurs in dissolved inorganic forms such as phosphate, in organic forms, in particles such as apatite minerals, and in living and dead organisms.
Biological recycling and burial create different pathways.
Phytoplankton and other primary producers take up dissolved phosphorus, which then moves through food webs. Respiration and regeneration return organic phosphorus to dissolved inorganic forms; upwelling returns phosphorus toward the surface. Some organic and inorganic phosphorus accumulates in sediments and becomes part of sedimentary rocks. Uplift, accretion, sea-level change, weathering, and erosion reconnect this long-term store to the ocean. Fertilizers and wastewater can add phosphorus through waterways, promoting eutrophication and altering food webs.
Connected concepts in other principles
Nitrogen cycleDistinguish abundant atmospheric nitrogen from the forms organisms can use.
Microorganisms transform nitrogen into usable forms.
Life needs nitrogen for amino acids and proteins. Atmospheric nitrogen gas cannot be used directly by most organisms. Some bacteria, including cyanobacteria, fix nitrogen into forms that can enter biomass and support other organisms. Nitrogen cycles among nitrate, nitrite, ammonium, and organic compounds through fixation, nitrification, denitrification, assimilation, ammonification, and anaerobic ammonium oxidation.
Nitrogen compounds have different oxidation states: nitrate, nitrite and ammonium participate in different chemical and biological transformations. Organic nitrogen compounds include urea; a list of nitrogen forms should distinguish chemical state from biological role.
Nitrogen cycles through food webs, sediments, and human inputs.
Primary producers take up dissolved nitrogen; consumers obtain it through food webs. Respiration and regeneration return organic nitrogen to dissolved inorganic forms, and upwelling brings nitrogen toward the surface. Some organic nitrogen is buried and incorporated into sedimentary rocks, which uplift, accretion, and sea-level changes can expose to weathering and erosion. Fertilizers, wastewater, and fossil-fuel combustion add nitrogen through waterways or the atmosphere; excess inputs can promote eutrophication and alter food webs.
Connected concepts in other principles
Silica cycleConnect mineral weathering with the hard parts of organisms and their sedimentary record.
Some organisms build hard parts from silica.
Diatoms, radiolarians, and some sponges build silica structures, including frustules, tests, spines, and spicules. Weathering on land and volcanic activity supply silicon to the ocean; rivers carry weathering products seaward. Silicon occurs in dissolved forms and in particles, including minerals and biological skeletal material.
Dissolution, burial, and weathering complete the cycle.
Most biogenic silica dissolves after organisms die; upwelling returns dissolved silicon toward surface waters. A smaller fraction is buried and transformed into sedimentary materials such as chert, diatomite, and clay minerals. Uplift, accretion, and sea-level changes can expose these materials on land, where weathering and erosion return them toward the ocean. Human changes to continental weathering, including acid rain, and to the water cycle can change silicon delivery to the ocean.
Teaching resources
Start here
Explore this principle with the platform
WebGIS
Locate ocean features and discuss the geological processes in CFD branch A. Use the original sheet to trace the chemical cycles.
Sources and curriculum alignment
Grades 9–12 conceptual alignment: Adapted from NMEA Ocean Literacy Scope and Sequence under CC BY-NC-SA 4.0.
Adapted from the NMEA Grades 9–12 Principle 2 CFD (2021, handbook page 61). The guide follows the rock-cycle branch and all four biogeochemical cycles. Classroom tasks and platform links are Blue Biome teaching suggestions, not activities supplied by NMEA.
Source concepts and connections
The notes below paraphrase the English NMEA source. They also explain qualified adaptations and corrected references.
A · Rocks break down and materials move to the ocean.
- Weathering and erosion move land-derived rock material into the ocean as rocks continually form and break down.
Adaptation notes (English)
Describe pathways and use can for subduction and uplift rather than implying every rock or plate follows one inevitable path. Define accretion as material addition, not every process that affects a plate.
Read the explanationA1 · Rocks break down and materials move to the ocean.
- Weathering, erosion, subduction, and uplift break down and recycle rocks.
A2 · Rocks break down and materials move to the ocean.
- Rivers and atmospheric deposition deliver weathering products.
- ocean materials have different residence times.
A3 · Subduction reshapes plate boundaries.
- Dense oceanic plates subduct beneath continental plates and can cause continental uplift.
Adaptation notes (English)
Describe pathways and use can for subduction and uplift rather than implying every rock or plate follows one inevitable path. Define accretion as material addition, not every process that affects a plate.
Read the explanationA4 · Subduction reshapes plate boundaries.
- Subduction can add scraped-off oceanic rocks and sediments to continental margins.
- Subduction carries some rocks and sediments into the upper mantle while other material joins the continental edge.
A5 · Subduction reshapes plate boundaries.
- Trenches, island arcs, stratovolcanoes, and some mountain ranges are associated with subduction.
A6 · Subduction reshapes plate boundaries.
- Subducted plate boundaries characterize parts of the ocean such as the Pacific Rim.
A7 · Sedimentation, accretion, and volcanism form new rocks.
- Accretion, sedimentation, volcanism, and igneous processes continually form rocks.
A8 · Sedimentation, accretion, and volcanism form new rocks.
- Accretion adds material to a tectonic plate.
- the diagram connects this with subduction, uplift, sea-level change, and waves.
Adaptation notes (English)
Describe pathways and use can for subduction and uplift rather than implying every rock or plate follows one inevitable path. Define accretion as material addition, not every process that affects a plate.
Read the explanationA9 · Sedimentation, accretion, and volcanism form new rocks.
- Sedimentation includes gravity settling and material moved along the seafloor by waves or currents.
A10 · Sedimentation, accretion, and volcanism form new rocks.
- Volcanism at plate boundaries and within plates and other igneous processes create rock formations.
- Uplift and erosion expose igneous and sedimentary rocks.
B · The ocean connects Earth’s chemical reservoirs.
- The ocean is central to biogeochemical cycles essential for life.
B1 · The ocean connects Earth’s chemical reservoirs.
- Elements occur in seawater at different concentrations.
- many are essential to life, while silicon and strontium are needed by some organisms.
B2 · Carbon moves between inorganic and organic forms.
- The ocean is the largest reservoir of rapidly cycling organic and inorganic carbon.
B3 · Carbon moves between inorganic and organic forms.
- Atmospheric carbon dioxide enters through diffusion, mixing, and bubbles.
- ocean carbon occurs in dissolved organic and inorganic forms and in particles and organisms.
- Convective mixing exchanges carbon-containing materials between water layers.
Adaptation notes (English)
Use named inorganic/organic pools rather than copying ambiguous or incomplete chemical formula lists. Do not classify methane as inorganic carbon or imply all sugars and lipids contain phosphorus or nitrogen. Describe dissolved silicon separately from particulate silica.
Read the explanationB4 · Carbon moves between inorganic and organic forms.
- Photoautotrophs and chemoautotrophs fix inorganic carbon into organic matter.
B5 · Carbon moves between inorganic and organic forms.
- Respiration converts much organic carbon back to inorganic carbon.
B6 · Carbon moves between inorganic and organic forms.
- Some organic carbon sinks, accumulates on the seafloor, and may become fossil fuel.
B7 · Carbonate shells connect life with the rock cycle.
- Organisms use dissolved inorganic carbon to form calcium carbonate shells and skeletal parts.
B8 · Carbonate shells connect life with the rock cycle.
- Much shell-derived calcium carbonate dissolves in the deep ocean.
B9 · Carbonate shells connect life with the rock cycle.
- Some shell and coral carbonate accumulates in limestone, chalk, and carbonate banks.
B10 · Carbonate shells connect life with the rock cycle.
- Uplift, accretion, and sea-level change can expose carbon-bearing marine rocks to weathering and erosion on land.
- Organic and inorganic sedimentary carbon both have geological return pathways through uplift, exposure and weathering.
B11 · Carbonate shells connect life with the rock cycle.
- Fossil-fuel combustion transfers organic carbon to atmospheric carbon dioxide and affects climate and ocean pH.
B12 · Phosphorus supports essential cellular compounds.
- Life needs phosphorus for ATP, DNA, and phospholipids.
B13 · Phosphorus supports essential cellular compounds.
- Weathering of terrestrial rocks is the main ocean phosphorus source.
B14 · Phosphorus supports essential cellular compounds.
- Ocean phosphorus occurs in dissolved inorganic and organic forms, particles including apatite, and organisms.
Adaptation notes (English)
Use named inorganic/organic pools rather than copying ambiguous or incomplete chemical formula lists. Do not classify methane as inorganic carbon or imply all sugars and lipids contain phosphorus or nitrogen. Describe dissolved silicon separately from particulate silica.
Read the explanationB15 · Biological recycling and burial create different pathways.
- Producers take up phosphorus, food webs transfer it, regeneration returns inorganic forms, and upwelling returns phosphorus to the surface.
B16 · Biological recycling and burial create different pathways.
- Some organic and inorganic phosphorus enters sediments and later sedimentary rocks.
Adaptation notes (English)
Use named inorganic/organic pools rather than copying ambiguous or incomplete chemical formula lists. Do not classify methane as inorganic carbon or imply all sugars and lipids contain phosphorus or nitrogen. Describe dissolved silicon separately from particulate silica.
Read the explanationB17 · Biological recycling and burial create different pathways.
- Uplift, accretion, and sea-level changes can expose phosphorus-bearing marine rocks to weathering and erosion.
B18 · Biological recycling and burial create different pathways.
- Fertilizer and wastewater phosphorus can reach the ocean through waterways, fuel eutrophication, and alter food webs.
Adaptation notes (English)
Treat eutrophication as nutrient enrichment that can promote blooms and alter food webs, not as a synonym for harmful algal blooms.
Read the explanationB19 · Microorganisms transform nitrogen into usable forms.
- Life needs nitrogen for amino acids and proteins.
- most organisms cannot directly use atmospheric nitrogen gas.
B20 · Microorganisms transform nitrogen into usable forms.
- Nitrogen-fixing bacteria including cyanobacteria make nitrogen available to marine life.
B21 · Microorganisms transform nitrogen into usable forms.
- Biological transformations cycle nitrogen among inorganic and organic forms through fixation, nitrification, denitrification, assimilation, ammonification, and anaerobic ammonium oxidation.
- Nitrogen forms have different oxidation states; urea is an organic nitrogen compound.
B22 · Nitrogen cycles through food webs, sediments, and human inputs.
- Producers take up nitrogen, food webs transfer it, regeneration returns inorganic forms, and upwelling returns nitrogen to the surface.
B23 · Nitrogen cycles through food webs, sediments, and human inputs.
- Some organic nitrogen enters sediments and becomes organic matter in sedimentary rocks.
Adaptation notes (English)
Use named inorganic/organic pools rather than copying ambiguous or incomplete chemical formula lists. Do not classify methane as inorganic carbon or imply all sugars and lipids contain phosphorus or nitrogen. Describe dissolved silicon separately from particulate silica.
Read the explanationB24 · Nitrogen cycles through food webs, sediments, and human inputs.
- Uplift, accretion, and sea-level changes expose nitrogen-bearing marine rocks to weathering and erosion.
B25 · Nitrogen cycles through food webs, sediments, and human inputs.
- Nitrogen from fertilizers, wastewater, and fossil-fuel combustion reaches the ocean through water or air and can fuel eutrophication and alter food webs.
Adaptation notes (English)
Treat eutrophication as nutrient enrichment that can promote blooms and alter food webs, not as a synonym for harmful algal blooms.
Read the explanationB26 · Some organisms build hard parts from silica.
- Diatoms, radiolarians, and sponges use silica for hard parts such as tests, frustules, spines, and spicules.
B27 · Some organisms build hard parts from silica.
- Weathering and volcanic activity supply ocean silica.
- rivers transport land-weathering products.
B28 · Some organisms build hard parts from silica.
- Ocean silicon occurs in dissolved forms and in particulate minerals and biogenic skeletons.
Adaptation notes (English)
Use named inorganic/organic pools rather than copying ambiguous or incomplete chemical formula lists. Do not classify methane as inorganic carbon or imply all sugars and lipids contain phosphorus or nitrogen. Describe dissolved silicon separately from particulate silica.
Read the explanationB29 · Dissolution, burial, and weathering complete the cycle.
- Most biogenic silica dissolves after death.
- upwelling returns dissolved silicon to the surface.
B30 · Dissolution, burial, and weathering complete the cycle.
- A smaller silica fraction is buried and transformed into sedimentary materials including chert, diatomite, and clay minerals.
B31 · Dissolution, burial, and weathering complete the cycle.
- Uplift, accretion, and sea-level changes expose silica-bearing marine rocks to weathering and erosion.
B32 · Dissolution, burial, and weathering complete the cycle.
- Human effects on weathering, including acid rain, and on the water cycle can change silica delivery to the ocean.
Concept pathways (English)
Rock cycle and plate tectonics: Weathering, erosion, sedimentation, accretion, and volcanism connect land and ocean.
Carbon cycle: Trace rapidly recycled carbon alongside the longer routes through sediments, rocks, and fossil fuels.
Phosphorus cycle: Follow phosphorus from weathered rocks through organisms, seawater, and sediments.
Nitrogen cycle: Distinguish abundant atmospheric nitrogen from the forms organisms can use.
Silica cycle: Connect mineral weathering with the hard parts of organisms and their sedimentary record.