Ocean Acidification: Saturation State
DetailsPermalink to Details
- Added to the Catalog
- Available for
- Water: Life, Human Impact, Chemistry
- Carbon Cycle
- Marine Ecosystems
- Ocean Acidificaiton
DescriptionPermalink to Description
Ocean acidification is an often overlooked consequence of humankind's release of carbon dioxide emissions into the atmosphere from fossil fuel burning. Excess carbon dioxide enters the ocean and reacts with water to form carbonic acid, which decreases ocean pH (i.e., makes seawater less basic), and lowers carbonate ion concentrations. Organisms such as corals, clams, oysters, and some plankton use carbonate ions to create their shells and skeletons. Decreases in carbonate ion concentration will make it difficult for these creatures to form hard structures, particularly for juveniles. Ocean acidification may cause some organisms to die, reproduce less successfully, or leave an area. Other organisms such as seagrass and some plankton species may do better in oceans affected by ocean acidification because they use carbon dioxide to photosynthesize, but do not require carbonate ions to survive. Ocean ecosystem diversity and ecosystem services may therefore change dramatically from ocean acidification.
This datasets shows computer model simulations of surface ocean aragonite saturation state from 1861 to 2100, based on historical data and future projections of carbon dioxide emissions, with continents and coral reefs in purple marked. Aragonite saturation state is commonly used to track ocean acidification because it is a measure of carbonate ion concentration. Aragonite is one of the more soluble forms of calcium carbonate and is widely used by marine calcifiers (organisms with calcium carbonate structures). Corals and other calcifiers are more likely to survive and reproduce when the saturation state is greater than three. When aragonite saturation state falls below 3, these organisms become stressed, and when saturation state is less than 1, shells and other aragonite structures begin to dissolve. The predicted pH decrease of approximately 0.3 units during the 21st century would be a greater change than possibly at any time in the last 300 million years.
The model simulation is driven with atmospheric emissions based on records of atmospheric carbon dioxide levels for past dates, and the CMIP5 IPCC RCP 8.5 scenario for future dates (approx. 950 ppm atmospheric CO2 by 2100).
Next Generation Science StandardsPermalink to Next Generation Science Standards
Cross-cutting ConceptsPermalink to Cross-cutting Concepts
C1 Patterns. Students identify similarities and differences in order to sort and classify natural objects and designed products. They identify patterns related to time, including simple rates of change and cycles, and to use these patterns to make predictions.
C5 Energy and Matter. Students learn matter is made of particles and energy can be transferred in various ways and between objects. Students observe the conservation of matter by tracking matter flows and cycles before and after processes and recognizing the total weight of substances does not change.
C7 Stability and Change. Students measure change in terms of differences over time, and observe that change may occur at different rates. Students learn some systems appear stable, but over long periods of time they will eventually change.
C1 Patterns. Students recognize that macroscopic patterns are related to the nature of microscopic and atomic-level structure. They identify patterns in rates of change and other numerical relationships that provide information about natural and human designed systems. They use patterns to identify cause and effect relationships, and use graphs and charts to identify patterns in data.
C5 Energy and Matter. Students learn matter is conserved because atoms are conserved in physical and chemical processes. They also learn within a natural or designed system, the transfer of energy drives the motion and/or cycling of matter. Energy may take different forms (e.g. energy in fields, thermal energy, energy of motion). The transfer of energy can be tracked as energy flows through a designed or natural system.
C7 Stability and Change. Students explain stability and change in natural or designed systems by examining changes over time, and considering forces at different scales, including the atomic scale. Students learn changes in one part of a system might cause large changes in another part, systems in dynamic equilibrium are stable due to a balance of feedback mechanisms, and stability might be disturbed by either sudden events or gradual changes that accumulate over time
C1 Patterns. Students observe patterns in systems at different scales and cite patterns as empirical evidence for causality in supporting their explanations of phenomena. They recognize classifications or explanations used at one scale may not be useful or need revision using a different scale; thus requiring improved investigations and experiments. They use mathematical representations to identify certain patterns and analyze patterns of performance in order to re-engineer and improve a designed system.
C3 Scale Proportion and Quantity. Students understand the significance of a phenomenon is dependent on the scale, proportion, and quantity at which it occurs. They recognize patterns observable at one scale may not be observable or exist at other scales, and some systems can only be studied indirectly as they are too small, too large, too fast, or too slow to observe directly. Students use orders of magnitude to understand how a model at one scale relates to a model at another scale. They use algebraic thinking to examine scientific data and predict the effect of a change in one variable on another (e.g., linear growth vs. exponential growth).
C5 Energy and Matter. Students learn that the total amount of energy and matter in closed systems is conserved. They can describe changes of energy and matter in a system in terms of energy and matter flows into, out of, and within that system. They also learn that energy cannot be created or destroyed. It only moves between one place and another place, between objects and/or fields, or between systems. Energy drives the cycling of matter within and between systems. In nuclear processes, atoms are not conserved, but the total number of protons plus neutrons is conserved.
C7 Stability and Change. Students understand much of science deals with constructing explanations of how things change and how they remain stable. They quantify and model changes in systems over very short or very long periods of time. They see some changes are irreversible, and negative feedback can stabilize a system, while positive feedback can destabilize it. They recognize systems can be designed for greater or lesser stability
Disciplinary Core IdeasPermalink to Disciplinary Core Ideas
ESS2.C The Roles of Water in Earth's Processes. Most of Earth’s water is in the ocean and much of the Earth’s fresh water is in glaciers or underground.
ESS2.E Biogeology. Living things can affect the physical characteristics of their environment.
ESS3.A Natural Resources. Energy and fuels humans use are derived from natural sources and their use affects the environment. Some resources are renewable over time, others are not.
ESS3.C Human Impact on Earth systems. Societal activities have had major effects on the land, ocean, atmosphere, and even outer space. Societal activities can also help protect Earth’s resources and environments.
LS1.A Structure and Function. Organisms have both internal and external macroscopic structures that allow for growth, survival, behavior, and reproduction.
LS1.B Growth and Development of Organisms. Reproduction is essential to every kind of organism. Organisms have unique and diverse life cycles.
LS2.B Cycles of Matter and Energy Transfer in Ecosystems. Matter cycles between the air and soil and among organisms as they live and die.
PS1.A Structure of Matter. Because matter exists as particles that are too small to see, matter is always conserved even if it seems to disappear. Measurements of a variety of observable properties can be used to identify particular materials.
ESS2.C The Roles of Water in Earth's Processes. Water cycles among land, ocean, and atmosphere, and is propelled by sunlight and gravity. Density variations of sea water drive interconnected ocean currents. Water movement causes weathering and erosion, changing landscape features.
ESS3.A Natural Resources. Humans depend on Earth’s land, ocean, atmosphere, and biosphere for different resources, many of which are limited or not renewable. Resources are distributed unevenly around the planet as a result of past geologic processes
ESS3.C Human Impact on Earth systems. Human activities have altered the biosphere, sometimes damaging it, although changes to environments can have different impacts for different living things. Activities and technologies can be engineered to reduce people’s impacts on Earth.
LS1.A Structure and Function. All living things are made up of cells. In organisms, cells work together to form tissues and organs that are specialized for particular body functions
LS1.B Growth and Development of Organisms. Animals engage in behaviors that increase the odds of reproduction. An organism’s growth is affected by both genetic and environmental factors.
LS2.A Interdependent Relationships in Ecosystems. Organisms and populations are dependent on their environmental interactions both with other living things and with nonliving factors, any of which can limit their growth. Competitive, predatory, and mutually beneficial interactions vary across ecosystems but the patterns are shared.
LS2.B Cycles of Matter and Energy Transfer in Ecosystems. The atoms that make up the organisms in an ecosystem are cycled repeatedly between the living and nonliving parts of the ecosystem. Food webs model how matter and energy are transferred among producers, consumers, and decomposers as the three groups interact within an ecosystem.
LS2.C Ecosystem Dynamics, Functioning and Resilience. Ecosystem characteristics vary over time. Disruptions to any part of an ecosystem can lead to shifts in all of its populations. The completeness or integrity of an ecosystem’s biodiversity is often used as a measure of its health.
PS1.A Structure of Matter. The fact that matter is composed of atoms and molecules can be used to explain the properties of substances, diversity of materials, states of matter, phase changes, and conservation of matter.
ESS2.C The Roles of Water in Earth's Processes. The planet’s dynamics are greatly influenced by water’s unique chemical and physical properties.
ESS2.E Biogeology. The biosphere and Earth’s other systems have many interconnections that cause a continual co-evolution of Earth’s surface and life on it
ESS3.A Natural Resources. Resource availability has guided the development of human society and use of natural resources has associated costs, risks, and benefits.
ESS3.C Human Impact on Earth systems. Sustainability of human societies and the biodiversity that supports them requires responsible management of natural resources, including the development of technologies that produce less pollution and waste and that preclude ecosystem degradation.
LS1.A Structure and Function. Systems of specialized cells within organisms help perform essential functions of life. Any one system in an organism is made up of numerous parts. Feedback mechanisms maintain an organism’s internal conditions within certain limits and mediate behaviors.
LS2.A Interdependent Relationships in Ecosystems. Ecosystems have carrying capacities resulting from biotic and abiotic factors. The fundamental tension between resource availability and organism populations affects the abundance of species in any given ecosystem.
LS2.B Cycles of Matter and Energy Transfer in Ecosystems. Photosynthesis and cellular respiration provide most of the energy for life processes. Only a fraction of matter consumed at the lower level of a food web is transferred up, resulting in fewer organisms at higher levels. At each link in an ecosystem elements are combined in different ways and matter and energy are conserved. Photosynthesis and cellular respiration are key components of the global carbon cycle.
PS1.A Structure of Matter. The sub-atomic structural model and interactions between electric charges at the atomic scale can be used to explain the structure and interactions of matter, including chemical reactions and nuclear processes. Repeating patterns of the periodic table reflect patterns of outer electrons. A stable molecule has less energy than the same set of atoms separated; one must provide at least this energy to take the molecule apart
PS1.B Chemical Reactions. Chemical processes are understood in terms of collisions of molecules, rearrangement of atoms, and changes in energy as determined by properties of elements involved.
Notable FeaturesPermalink to Notable Features
- Decreases in carbonate ion concentration will make it difficult for these creatures to form hard structures, particularly for juveniles
- Aragonite saturation state is commonly used to track ocean acidification because it is a measure of carbonate ion concentration.
- When aragonite saturation state falls below 3, these organisms become stressed, and when saturation state is less than 1, shells and other aragonite structures begin to dissolve.
Data SourcePermalink to Data Source
NOAA GFDL Earth System Model (ESM2M)