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Assessment schedule: Science 90953 Carbon Cycling in the Southern Ocean
Judgements for Achievement
The student demonstrates understanding of carbon
cycling.
The student:
 presents at least two complete examples that
describe the addition, removal, and storage
processes of the carbon cycle in the context of the
southern ocean. This includes how long carbon
remains in some stages of the cycle
o dissolving in water
o photosynthesis by phytoplankton
o sedimentation of phytoplankton bodies
o outgassing of CO2 from ocean
o burning oil and gas
 identifies the links between the addition, removal,
and storage of carbon
 arranges and connects these examples in valid
ways to show carbon cycling
 shows the links between the different stages of
carbon cycling
 describes how key stages of carbon cycling are
linked, taking into consideration the addition,
removal, and storage of carbon
 may support their report with data, information
and/or visual images gathered from any
experiments, field trips, or other activities, where
relevant.
Judgements for Achievement with Merit
The student demonstrates in-depth understanding of
carbon cycling.
As for achieved plus the student:
 shows the links between the different stages of
carbon cycling and the two different examples
 explains how key stages of carbon cycling are
linked, taking into consideration the addition,
removal, and storage of carbon
Judgements for Achievement with Excellence
The student demonstrates comprehensive
understanding of carbon cycling.
As for merit plus the student:
 shows and explains the multiple links between key
stages of carbon cycling, and the multiple links
between the two different examples
 explains the multiple links between key stages of
carbon cycling, taking into consideration the
addition, removal, and storage of carbon
Final grades will be decided using professional judgement based on a holistic examination of the evidence provided against the criteria in the Achievement
Standard.
For Example:
Evidence for Achievement
Strong winds mix carbon dioxide into waters of the
southern ocean, removing it from the atmosphere.
Phytoplankton use carbon dioxide in the water when
they carry out photosynthesis, turning it into sugars and
other chemicals in their body.
Phytoplankton also release carbon dioxide when they
break down sugars during respiration.
Phytoplankton usually only live for a few days so
carbon is stored in their bodies short term.
Carbon dioxide in the water can also be released back
into the atmosphere from the southern ocean.
Evidence for Achievement with Merit
Evidence for Achievement with Excellence
Strong winds mix carbon dioxide into the waters of the
southern ocean where it is dissolved, removing it from
the atmosphere.
Strong winds mix carbon dioxide into the waters of the
southern ocean where it is dissolved, removing it from
the atmosphere. The cool waters of the southern ocean
allow for a high concentration of carbon dioxide to
remain dissolved in the water.
Phytoplankton use carbon dioxide in the water when
they carry out photosynthesis, turning it into sugars and
other chemicals in their bodies.
Phytoplankton also release carbon dioxide when they
break down sugars during respiration to provide
themselves with energy.
Phytoplankton only live for a few days so carbon is
stored in their bodies short term.
When phytoplankton die they sink to the deep ocean
and form part of the sediment. Decomposers can break
down the carbon in the bodies of phytoplankton
releasing it into the water.
Carbon dioxide in the water can also be released back
into the atmosphere from the southern ocean.
If the phytoplankton are buried before decomposers
break them down their bodies can be trapped in the
sediment sometimes for millions of years. Over time
the chemicals in their bodies are converted into oil and
natural gas.
Phytoplankton use carbon dioxide in the water when
they carry out photosynthesis, turning it into sugars and
other chemicals in their bodies.
Phytoplankton also release carbon dioxide when they
break down sugars during respiration to provide
themselves with energy.
Phytoplankton only live for a few days so carbon is
stored in their bodies short term.
When phytoplankton die they sink to the deep ocean
and form part of the sediment. Decomposers can break
down the carbon in the bodies of phytoplankton
releasing it into the water.
If the phytoplankton are buried before decomposers
break them down their bodies can be trapped in the
sediment sometimes for millions of years. Over time
the chemicals in their bodies are compressed by
sediments and are slowly converted into oil and natural
gas. These chemicals are known as fossil fuels and
humans burn them to produce energy. As they are
burned, carbon dioxide is released into the
atmosphere. The burning of fossil fuels is causing a
sharp rise in atmospheric carbon dioxide.
In some regions of the southern ocean water rich in
carbon dioxide is rising from great depths up to the
surface. The carbon dioxide is then released back into
the atmosphere.