Ausgeology. Senior secondary lessons

SACE Stage 2 Earth and Environmental Science · Topic 1: Earth system

Earth system.

The Coorong is a long, shallow lagoon on the coast of South Australia, where the River Murray meets the sea. Use it to see how the geosphere, atmosphere, hydrosphere and biosphere work as one system, follow how they change, then plan a study of your own.

How the lesson works

1 · See the system

Screens 2 to 4. Sort the parts of the Coorong into spheres, including the parts you can’t see, then link them in a table and a web of causes and effects.

2 · Follow the changes

Screens 5 to 8. Place changes in time and space, read patterns in real data, follow an oil spill through the spheres, and predict the Coorong’s future.

3 · Plan a study

Screens 9 and 10. Plan an Earth system study of your own, then show what you know.

What we are learning

How the four spheres and their visible and hidden parts interact, how changes spread through them over different time-scales and spatial scales, how to tell cyclic patterns from unpredictable ones, and how to plan a field investigation of a local area.

I can

  • 1name visible and hidden components of each of the four spheres.
  • 2identify interactions between components of different spheres.
  • 3organise components and processes into a web of interactions and find its feedback loops.
  • 4explain how natural and human-induced factors cause changes in the spheres.
  • 5describe changes that happen over different time-scales and spatial scales.
  • 6tell cyclic patterns from unpredictable ones in data.
  • 7examine how interactions between spheres changed after a past event.
  • 8predict future changes in an area and explain what limits the prediction.
  • 9plan an Earth system study with primary and secondary data and a risk assessment.

SACE Stage 2 Earth and Environmental Science, Topic 1: Earth system. This lesson covers both Science Understanding statements and lays the groundwork for the Earth system study. The teacher notes at the end quote the statements in full.

My notebook

Printable activity

Field sheet

Three pages, one box for each screen or pair of screens: components, an interaction table, space to draw a web, scales and patterns, past and future, and a study plan. Use it with the lesson, then take it into the field. Print one per student.

Field sheet (PDF) Editable (Word)

1See the system

The four spheres.

What is the Coorong made of, and which of its parts can you not see?

Every part of a place belongs to one or more of Earth’s four spheres. Some parts are easy to see. Others are underground, dissolved in water or too small to see.

This screen · about 20 minutes

  1. Read about the Coorong and the four spheres.
  2. Sort the parts of the Coorong you can see into spheres.
  3. Add what you can’t see, and sort those parts too.
  4. Read the cards on hidden parts of the Earth, and answer the check.

The Coorong

The Coorong is a chain of long, shallow lagoons on the coast of South Australia, more than 100 km long; sources give lengths from about 110 to 140 km. A lagoon, it is separated from the Southern Ocean by the dunes of the Younghusband Peninsula, and “Exchange with the ocean occurs through the Murray Mouth, which is located near Goolwa” (Brookes and others, 2022). Five barrages, built between 1935 and 1940, separate it from Lake Alexandrina, where the River Murray ends. The North Lagoon, near the Mouth, was historically an estuary; since European settlement the South Lagoon has usually been hypersaline (Brookes and others, 2022).

The Coorong and Lakes Alexandrina and Albert were listed as a Wetland of International Importance under the Ramsar Convention on 1 November 1985. The Ngarrindjeri are the traditional owners of the Coorong, Lower Lakes and Murray Mouth (DEWNR, 2014), and “‘Kurangk’ is the name given to the area by the Ngarrindjeri people, meaning long narrow neck” (Government of South Australia, 2019).

Earth’s four spheres, as NASA describes them

Geosphere

The solid Earth

“associated with solid portions of the Earth”. It includes “rocks, sediments and soils, surface landforms and the processes that shape the Earth’s surface”, and reaches down through the crust and mantle to the core.

Atmosphere

The air

The gases around and above the surface. It relates to “weather, clouds, or aerosols (particles in the air)”.

Hydrosphere

The water

“water in solid (ice) and liquid states”: oceans, rivers, lakes, groundwater and ice. Water vapour “can be also considered as a feature of the atmosphere”.

Biosphere

Living things

“living systems such as biomes and ecosystems”, on land and in water, “and even life we cannot see with the naked eye”. People are part of it.

Source: NASA, My NASA Data, “Our Earth: A Web of Systems”, and NASA Scientific Visualization Studio (2026). NASA sometimes shows the frozen part of the hydrosphere, the cryosphere, as a fifth sphere, and the IPCC counts five parts in the climate system. The SACE outline uses four.

Hidden, but big

Hydrosphere

Water underground

Groundwater is 30.1% of Earth’s fresh water. Lakes and rivers together hold only about 0.27%.

USGS Water Science School (2018)

Biosphere

Life below the surface

The Deep Carbon Observatory (2018) estimated that about 70% of Earth’s bacteria and archaea live underground, holding 15 to 23 billion tonnes of carbon. Another estimate is several times larger: about 15% of the mass of all life (Bar-On and others, 2018). Soil may be home to 59 ± 15% of Earth’s species (Anthony and others, 2023).

Deep Carbon Observatory (2018); Bar-On and others (2018); Anthony and others (2023)

Geosphere

Carbon in the rocks

Just 0.2% of Earth’s carbon is above the surface. The rest is below it, in the crust, mantle and core.

Deep Carbon Observatory (2019)

Geosphere

Heat from inside

About 47 terawatts of heat flows out of Earth’s interior (Davies and Davies, 2010), and radioactive decay supplies about half of it (Lawrence Berkeley National Laboratory, 2011). The plates above the mantle move too: Australia’s plate moves about 7 cm a year (Geoscience Australia). Geologists still argue over what moves the plates most: convection in the mantle (SAGE), or forces at the plates’ edges, such as the pull of plates sinking at subduction zones (Earle, 2015).

Davies and Davies (2010); Lawrence Berkeley National Laboratory (2011); Geoscience Australia; SAGE; Earle (2015)

Why is groundwater a good example of a hidden component of the hydrosphere?

My notebook

1See the system

A web of causes and effects.

How does a change spread through the South Lagoon, and where does it come back round?

The table showed which spheres interact. A web shows which way each effect runs and whether it pushes the next part up or down. It also shows where a chain of effects comes back to where it started. Build a web for the South Lagoon from the evidence, then push a change through it.

This screen · about 20 minutes

  1. Read how to mark a link + or −.
  2. For each evidence card, choose the cause and the sign. Each correct card adds an arrow to the web.
  3. Decide whether each loop the web finds is reinforcing or balancing.
  4. Push a change through the web and follow it step by step. Then answer the check.

Reading a web

A + link means the two things move the same way: more of one, more of the other. A − link means they move opposite ways. Count the − links around a loop: none or an even number makes a reinforcing loop, and an odd number makes a balancing loop.

Why a web, not a chain?

In a chain, each cause has one effect. In the South Lagoon one change has several effects at once, and they can work against each other. Less river flow raises the salinity. Higher salinity harms Ruppia, but it also means less of the filamentous algae that shade and tangle Ruppia. Which effect is stronger depends on the size of each link, and the web does not show that. Only measurements in the field can.

In the web, less river flow raises the salinity of the South Lagoon. What does the web tell you about how this affects Ruppia?

My notebook

2Follow the changes

Time and space.

How long do changes in the Earth system take, how far do they reach, and what causes them?

A lightning strike lasts a fraction of a second and hits one spot. The ice ages came and went over tens of thousands of years and changed the whole planet. Changes in the spheres come in every length and size between these two, and their causes can be natural, human-induced or both.

This screen · about 20 minutes

  1. For each change, choose its time-scale and spatial scale, then decide whether its cause is natural, human-induced or both. Some changes fit more than one box.
  2. Look at where the human-induced changes fall on the chart.
  3. Read the chart of how long water stays in each part of the Earth system.
  4. Read about the mangroves, then answer the checks.

Natural, human-induced, or both?

Some changes have natural causes only, such as a volcanic eruption or the slow cycles of Earth’s orbit. Others are human-induced, such as clearing native vegetation or burning fossil fuels. Many have causes of both kinds. When sand blocked the Murray Mouth in 1981, a newspaper of the time blamed low river flow and the drought (SA Memory). People also take water from the river upstream, which cuts the average flow at the Murray Mouth by 61% (CSIRO, 2008). Low flow at the Mouth is partly a natural change and partly a human-induced one.

Causes that start far away or long ago

A change you measure at one site may have started somewhere else, or a long time before. The water in the Coorong fell as rain across the Murray–Darling Basin. Iron in the smoke from the 2019–20 Australian bushfires probably fed widespread blooms of phytoplankton in the Southern Ocean (Tang and others, 2021), thousands of kilometres downwind of the fires (Inside Science, 2021). On farmland, dryland salinity can show up long after the native vegetation was cleared: the Australian Bureau of Statistics (2002) says salinity problems “only become apparent after long time lags, often 100 years or more”.

Mangroves on the Northern Territory coast show a cause that started far away. Between late 2015 and early 2016, mangroves “died back along 1000 km of the shoreline of Australia’s remote Gulf of Carpentaria”, from the Roper River estuary in the Northern Territory east to Karumba in Queensland, affecting more than 7,400 hectares (Duke and others, 2017). Duke and others link the dieback to “an unusually lengthy period of severe drought conditions”, “unprecedented high temperatures” and “a temporary drop in sea level” of up to 20 cm. A later study found that the fall in sea level that came with the 2015–16 El Niño in the Pacific was “the crucial factor” (Abhik and others, 2021).

How long does water stay?

Data

Water moves through the spheres at very different speeds. On average, a molecule of water stays in the atmosphere for 8 days, but in the ocean for about 3,100 years (Earle, 2023).

Show the numbers as a table

The scale multiplies at each step, so days and thousands of years fit on one chart. A bar with a lighter end shows a range. These are averages, and some water moves through much faster or slower. Sources also disagree: NOAA gives 9 to 10 days for the atmosphere, and the Science Learning Hub gives 40 to 400 years for glaciers. Data: Earle (2023), Table 11.1.1.

Which change on the chart began in one place and changed conditions across the whole globe?

Why did mangroves die back along about 1,000 km of the Gulf of Carpentaria in 2015–16?

My notebook

2Follow the changes

Patterns in data.

Which changes repeat, which build up over time, and which happen at irregular times?

Measurements of the hydrosphere and atmosphere show three kinds of pattern. A cycle repeats at regular intervals, as the tides and the seasons do. A trend is a change in one direction over many years. Irregular events, such as storms, heatwaves and floods, come at times that do not repeat. One record can show a different pattern at each time-scale, so read each record over more than one.

This screen · about 20 minutes

  1. Choose a record and a view. Decide whether it shows a regular cycle, a trend or irregular events.
  2. Read values from the line, or open the table, to check your answer.
  3. Work through all three records.
  4. Read about El Niño and about cycles in field data, then answer the check.

A cycle without a timetable

Hydrosphere and atmosphere · 2026

El Niño

The Bureau of Meteorology calls the El Niño–Southern Oscillation “a natural cycle in the global climate system”. El Niño, its warm phase, “occurs on average every 3 to 5 years”, but the gap between events varies, so the next one cannot be read off a calendar. The Bureau declared an El Niño on 16 June 2026 (The Conversation, 2026). On 8 October the World Meteorological Organization reported that “El Niño is firmly established and strengthening rapidly”. It forecast that sea surface temperatures in the central equatorial Pacific (the Niño 3.4 region) would average about 3.7 °C above normal from October to December, the highest since observations began. That figure is a forecast, not a measurement.

Bureau of Meteorology (2023); Reid, The Conversation (2026); World Meteorological Organization (2026)

Cycles in your own data

Dissolved oxygen in water is lowest just after dawn and highest in the late afternoon (NSW DPI), so a reading at 7 am and a reading at 4 pm cannot be compared fairly. At a coastal site the water level depends on the state of the tide, and the Thevenard record shows the daily range itself changing over two weeks. Record the time of every measurement, and plan to measure at the same time of day, or the same stage of the tide, at each visit.

A student measures dissolved oxygen in a creek at 7 am one week and at 4 pm the next. The second reading is higher. What should the student conclude?

My notebook

2Follow the changes

An oil spill.

How did one spill move through all four spheres, and what did science add to the argument about cleaning it up?

On 24 March 1989 the tanker Exxon Valdez ran aground in Prince William Sound, Alaska. Its oil moved from the sea into the air, onto the shore, into the sediment and through living things. The clean-up raised a question that scientists studied for years afterwards: which methods help a coast recover, and which do more harm than the oil?

This screen · about 25 minutes

  1. Step through the spill and follow the oil from sphere to sphere.
  2. Read the chart of where the oil ended up.
  3. Sort the clean-up methods by what each one does with the oil.
  4. Read what the monitoring found and the case of the X-Press Pearl, then answer the check.

Where did it end up?

Data
  • Biosphere
  • Atmosphere
  • Geosphere
  • Hydrosphere
  • Taken away by people
Show the numbers as a table

Shares of the 11 million US gallons spilled, from the estimate by Wolfe and others (1994), as given by the Exxon Valdez Oil Spill Trustee Council. Microbes broke down more of the oil than people removed. The colours show the sphere where each share ended up; for the 50%, they show the living things that broke it down.

What does each method do with the oil?

0 of 7 sorted

Choose what each clean-up method does with the oil. The feedback says what happened when it was used.

What the monitoring found

From 1990 to 2000 NOAA monitored about 20 sites around Prince William Sound: some oiled and cleaned, some oiled but not cleaned, and some not oiled at all (NOAA). Sites washed with hot water “initially suffered more severe declines in population abundance than oiled and not-washed sites”, although both kinds of oiled site recovered by about 1992–93 (NOAA). Mearns Rock, a boulder that was oiled but never cleaned, had recovered within three to four years. Clams and softer beaches took about 10 to 12 years, and NOAA scientist Alan Mearns said “we think a lot of those were blown out by the high pressure washing” (NOAA, 2009).

NOAA now writes that hot-water washing “can damage plants and animals in the treated zone directly and indirectly, short-term and long-term”, but adds: “However, this does not mean we would eliminate its use in the future.” Other questions are still argued over. About 23,000 gallons of oil remain buried in some beaches, and NOAA calls its biological significance “unclear and a source of controversy”. The Pacific herring fishery collapsed in 1993 (Exxon Valdez Oil Spill Trustee Council), and scientists still disagree about how much the spill was to blame (Incardona and others, 2015).

A chemical spill

Sri Lanka · 2021

The X-Press Pearl

On 20 May 2021, off Colombo, chemical fumes began to rise from the container ship X-Press Pearl. Explosions on 25 May spread fire through the whole ship. The fire was under control by 31 May, and on 2 June the stern sank while the ship was being towed; by 17 June the whole ship lay on the seabed. Of its 1,486 containers, at least 81 carried dangerous goods, including 25 tonnes of nitric acid, and 87 carried about 1,680 tonnes of plastic pellets, or nurdles. UNEP called it “reportedly the single largest plastic spill on record”. Plastic washed up along about 300 km of coast, and coastal fishing was banned along 80 km; the livelihoods of an estimated 20,000 fishing families were affected (UNEP, 2021).

Science informed the response. The most contaminated burnt plastic sampled carried “the greatest amount of PAHs recorded for marine plastic debris”, and the unburnt pellets sampled carried about a hundredth as much (James and others, 2023). PAHs are potentially toxic chemicals that are also found in oil. A Woods Hole scientist, Chris Reddy, said the spill “almost amounts to two separate spills that potentially call for different clean-up strategies” (Woods Hole Oceanographic Institution, 2021). By 17 July, 251 dead turtles, 28 dolphins and 5 whales had washed ashore. The UN team cautioned “on causal attribution to the incident without scientific evidence”, because turtle strandings are normally high at the start of the monsoon and more people were watching for them (UNEP, 2021). In July 2025 Sri Lanka’s Supreme Court held the ship’s owner, operator and local agent liable and ordered an initial payment of US$1 billion. In September 2025, with the first instalment of at least US$250 million due, the operator said it and its insurer “cannot make the payment at this stage”.

UNEP (2021); James and others (2023); Woods Hole Oceanographic Institution (2021); Reed Smith (2025); Ship & Bunker (2025)

NOAA left some oiled shores uncleaned on purpose. What did these “set-aside sites” let scientists do?

My notebook

2Follow the changes

The Coorong: past and future.

How did the South Lagoon change through drought and flood, and what could happen to it next?

From 2007 to 2010 no river water flowed over the barrages into the Coorong. Floods followed in 2010–11, and in 2022–23 came the largest flood recorded in South Australia since 1956. Read what happened to the South Lagoon through these years, then use the record to predict the next twelve.

This screen · about 25 minutes

  1. Read the four events, from the Millennium Drought to 2025.
  2. Read the record of flow and salinity, year by year.
  3. Set the flow for each year from 2024 to 2035 and watch the predicted salinity. Try both estimates of the flow that resets the lagoon.
  4. Read what limits the prediction, and answer the check.

Drought, flood and a bloom

2007 to 2010

The Millennium Drought

No river water flowed over the barrages from 2007/08 to 2009/10 (Ye and others, 2020). “Prolonged drought and upstream diversion of water” dropped the water in the Lower Lakes below sea level, and South Lagoon salinity rose above 200 g/L at times (Kingsford and others, 2011). More than 200 km² of sediment around the lake margins was exposed, and when it was wetted again by rain or rising lake water, the water above it turned acid in several places, down to pH 2 to 3 (Mosley and others, 2014). Ruppia tuberosa declined from 2000 and was recorded as completely absent from the South Lagoon in 2010 (Brookes and others, 2018).

2010 to 2012

The floods return

About 12,800 GL flowed over the barrages in 2010/11 and about 9,000 GL in 2011/12 (Ye and others, 2020). Salinity fell, but Ruppia tuberosa’s recovery in the South Lagoon was “slow and limited” (Paton and others, 2017). In 2011 the stores of its seeds and turions in the mud were around 100-fold lower than in the early 1990s (Paton and Bailey, 2012).

2022 to 2023

The largest flood since 1956

Flow into South Australia peaked at 186,000 ML a day on 22 December 2022 (Mosley and others, 2024). South Lagoon salinity fell from a seasonal peak of 114 g/L in 2022 to an average of 43 g/L in January 2023 (DEW, 2023b). Ruppia tuberosa held on until salinity fell below 35 g/L, and the plants died off fully at 10 g/L (Mosley and others, 2024). Salinity stayed below 60 g/L in both lagoons for most of 2023, and once the high flows ended it rose again, particularly in the South Lagoon (Goyder Institute, 2024c).

2025

A harmful algal bloom

A bloom of the alga Karenia started in South Australian waters in March 2025. Experts named three plausible contributing factors: a marine heatwave from September 2024, with sea temperatures about 2.5 °C warmer than usual; extra nutrients washed into the sea by the 2022–23 flood; and an “unprecedented cold-water upwelling in summer 2023-24”. Experts believe the alga entered the Coorong’s North Lagoon through the Murray Mouth during a strong cold front (DEW, 2025).

Flow and salinity, year by year

Data
Show the numbers as a table

Flows are for water years, July to June. The 2022/23 bar covers July 2022 to March 2023 only, so the whole year was larger, and no totals were found for 2013/14 or 2014/15. No continuous record of South Lagoon salinity was found, so the lower chart shows the ranges and single values that monitoring reports give for each year.

A rule of thumb for the future

Scientists predict the Coorong’s future with computer models of its water and salt. The model below is far simpler: a rule of thumb taken from the record. Between high flows, South Lagoon salinity has risen by about 11 to 16 g/L a year (DEW, 2021). A big enough flow brings it back down, but the published estimates of how big disagree, and they were written for slightly different goals. One 2010 report says “A barrage release in the order of 3,000 GL would be required to reset Coorong salinity to the extent that will be achieved by” a planned pumping scheme (Taylor, 2010). Another says “barrage flows in excess of 10,000 GL” are needed “to restore target salinities” (DEH, 2010, citing Paton and others, 2009).

What limits the prediction?

Every prediction rests on assumptions. This one assumes the next twelve years behave like the years since 2010. It leaves out sea level, which is projected to rise by 22 to 25 cm by 2050 under high emissions (DEW, 2022); in one model study, “higher sea levels increased hydrodynamic connectivity between the Coorong’s two lagoons” (Lester and others, 2013). It leaves out people’s decisions about how much water to take from the river, and the same study found that “much of the degradation could be averted by reducing upstream extractions of water.” It cannot include events with no pattern in the record, such as the 2025 bloom.

In 2016/17 about 6,500 GL flowed over the barrages, and mean salinities at the South Lagoon monitoring sites were 62 to 70 psu. The year before, salinities there ranged from 74 to 117 psu (Ye and others, 2020). Which setting of the model fits this year better?

My notebook

3Plan a study

Plan a study.

How would you investigate interactions between the spheres at a site near you?

The subject outline says this topic “lays the foundation of scientific inquiry skills that students use in planning and implementing their Earth system study”. In that study you investigate a local environmental issue in the field, collect primary and secondary data, and analyse how two or more spheres interact. Start with a question that data can answer, then build a proposal around it.

This screen · about 30 minutes

  1. Sort six questions by whether data could answer them.
  2. Read what a proposal should include, and the tips for good fieldwork.
  3. Build your own study proposal, step by step, and copy the summary.
  4. Answer the check.

Could data answer it?

0 of 6 sorted

An investigable question is one you can answer by collecting and analysing data. Decide for each question.

What the proposal should include

For the Earth systems study, “The investigation must include collection and analysis of both primary and secondary data.” The outline lists what the proposal should include:

  • “a statement of an investigable question or hypothesis”
  • “a rationale for and an outline of the proposed research approach and method”
  • “a list of equipment required”
  • “the procedure to be followed”
  • “the type of data that will be collected”
  • “a risk assessment that addresses safety, ethical, and legal considerations.”

SACE’s marking guide for the study adds “independent and dependent variables” to the first point.

Primary data are your own measurements and observations. Secondary data come from other sources, such as the Bureau of Meteorology’s records or satellite images. SACE’s subject assessment advice for 2025 says “Secondary data must also be included for comparison with the student’s primary data”, so look for secondary data you could link to your question before you settle on the final one. One draft of your proposal goes to your teacher for feedback and approval before you start, and you may trial your methods while you design it.

Good fieldwork

Calibrate

Check your meters

“Field meters will not provide accurate results unless they are calibrated before use.” Calibrate an EC or pH meter before each visit.

EPA SA (2007)

Choose sites

Typical, safe and easy to find

Sample away from the edge, because “edge water quality is generally not typical of the majority of the waterbody” (EPA SA). Do not wade in to get there. Keep “a good distance back from the edge of the bank” and extend a sampling pole to the middle of the waterway (Waterwatch). Choose sites that are safe to reach in all flows and “easily identifiable for later sampling” (EPA SA).

EPA SA (2007); Waterwatch, North Central CMA

Control

Keep conditions the same

Measure at the same time of day, at the same depth and in the same season at every visit, and use the same method at every site. Results from different methods are hard to compare.

EPA SA (2007); NSW DPI; Baruch and others (2018)

Repeat

Repeat readings and visits

Repeat each measurement, and compare your results with a partner’s. For soil infiltration, set up about three rings on each soil and average them. Plan several visits, too. SACE’s subject assessment advice says that in 2025 the more successful studies “collected data over a longer period of time (weeks to months) rather than a single lesson and/or day”.

Waterwatch, North Central CMA; AWRI (2010); SACE Board: 2025 subject assessment advice

The proposal’s risk assessment should address “safety, ethical, and legal considerations”. Which of these is a legal consideration?

My notebook

4Show what you know

Show what you know.

Nine questions, one for each of the I can statements on screen 1. You get one try at each, so think before you tap.

Which pair matches a hidden component of the Coorong with its sphere?

Which interaction starts in the atmosphere and changes the geosphere?

More Ruppia plants leave more seeds and turions, and more seeds and turions grow more plants. What kind of loop is this, and why does it matter?

Sand blocked the Murray Mouth in 1981. Which statement best explains the cause?

Which change works over the longest time-scale and at a global scale?

Which of these could you predict a year ahead from its own past record?

What did NOAA’s monitoring after the Exxon Valdez spill find about shores washed with hot water?

Published estimates of the flow that resets the South Lagoon range from about 3,000 GL to more than 10,000 GL. What does this mean for a prediction of its salinity?

Which plan best meets the requirements of the Earth systems study?

Printable activity

Field sheet

Three pages, one box for each screen or pair of screens: components, an interaction table, space to draw a web, scales and patterns, past and future, and a study plan. Use it with the lesson, then take it into the field. Print one per student.

Field sheet (PDF) Editable (Word)
For teachers

Curriculum

SACE Board of South Australia, Stage 2 Earth and Environmental Science Subject Outline (accredited for teaching at Stage 2 from 2018, reissued for 2025), Topic 1: Earth system. NT students take the subject as part of the NTCET. The topic outline says:

This topic lays the foundation of scientific inquiry skills that students use in planning and implementing their Earth system study. Students examine in detail the interaction between and within the Earth’s spheres — the atmosphere, hydrosphere, geosphere, and biosphere — and apply their learning to investigating their local area, as well as considering wider implications.

Students participate in field trips and use technology to develop their observational, recording, and analytical skills in preparation for the main study. They consider how their findings may provide advice to appropriate groups for future action.

The topic has two Science Understanding statements, and this lesson covers both. In the outline’s table the second statement’s list runs on into a new row, which holds the dot points on past and future changes; the lesson treats them as part of that statement. SACE’s grid “Integration of Earth System concepts into a teaching program” numbers them differently: the dot point on cyclic or unpredictable patterns and the one on past changes become 1.3, and predicting future changes becomes 1.4. The list below covers every dot point either way. The outline’s list of topics calls it “Topic 1: Earth systems”, and the topic’s own heading calls it “Topic 1: Earth system”; the lesson uses the heading.

The four Earth’s spheres are the geosphere, atmosphere, hydrosphere, and biosphere.

  • Investigate the components of each of the four spheres.
  • Identify visible and ‘hidden’ components and processes of spheres.
  • Identify interactions between components of spheres.
  • Describe dynamic relations within and between spheres.
  • Organise components and processes into a web of interactions.

A change in any one sphere can impact others at a range of temporal and spatial scales.

  • Explain how changes in spheres can be caused by natural or human-induced factors.
  • Describe that changes within a sphere and between spheres can occur over a variety of time-scales.
  • Identify patterns and changes over a variety of time-scales.
  • Discuss how a change in the Earth spheres can influence conditions at a range of spatial scales from local to global.
  • Explain that changes in spheres may have cyclic or unpredictable patterns.
  • Examine changes in interactions between Earth spheres that have occurred in the past.
  • Predict future changes within and between Earth spheres in a given area.

Where the lesson covers them:

  • The components of each sphere, visible and hidden: screen 2 (a cross-section of the Coorong with a second layer for what you can’t see, and cards on groundwater, life underground, carbon and heat inside the Earth), and exit question x1.
  • Interactions between components of spheres: screen 3 (a table of the four spheres with eleven interactions at the Coorong, and the 2026 Planetary Health Check), and x2.
  • Dynamic relations, and a web of interactions: screen 4 (a web of nine components in the South Lagoon, with signed links, two feedback loops and a tool that pushes a change through the web), and x3.
  • Natural and human-induced factors, time-scales, and spatial scales from local to global: screen 5 (eleven changes, from a lightning strike to the ice ages, placed on a chart of time against space; causes far away, including the 2015–16 mangrove dieback in the Gulf of Carpentaria; and how long water stays in each store), and x4 and x5.
  • Patterns and changes over a variety of time-scales, cyclic or unpredictable: screen 6 (sea level at Thevenard, temperature at Adelaide Airport and River Murray flow, each read at two or three time-scales, and El Niño in 2026), and x6.
  • Past changes in interactions: screen 7 (the Exxon Valdez spill through the four spheres, the clean-up debate and the X-Press Pearl) and screen 8 (the South Lagoon from the Millennium Drought to the 2025 algal bloom), and x7.
  • Predicting future changes in a given area: screen 8 (a rule of thumb for South Lagoon salinity to 2035, two published estimates of the flow that resets it, and what limits the prediction), and x8.
  • The Earth systems study: screen 9 (investigable questions, what the proposal should include, good fieldwork, and a proposal builder), and x9.

The lesson also uses these of the outline’s possible contexts:

Use ‘Planetary Boundaries’ from the Stockholm Resilience Institute with the movie ‘Breaking Boundaries’ by David Attenborough on Netflix as a discussion starter about the interconnections between spheres.

Investigate the interaction of the four Earth spheres in the local area and construct a table to show how the four Earth spheres can interact.

Use an example such as the Exxon Valdez oil spill or the fire on a cargo ship in Sri Lanka, to examine the contribution of science to the public debate on suitable methods to stimulate ecological recovery after an oil spill or chemical spill.

Gather background information, such as from maps and satellite imagery, and/or research the outcomes of prior studies.

Screen 3 has the 2026 Planetary Health Check from the Potsdam Institute for Climate Impact Research; the planetary boundaries page of the Stockholm Resilience Centre (the outline says Institute) gives the same count of seven of nine. Screen 3’s table and the field sheet suit a local study. Screen 7 covers both the Exxon Valdez and the X-Press Pearl. Screen 9 lists free map and satellite tools, and the FieldMove Clino app that the outline suggests for field notes, photos and strike and dip. The outline links NOAA’s oil spill education page: its activities are written for primary students, and Mearns Rock, used on screen 7, is the one Exxon Valdez item on it. Two other contexts can follow this lesson:

Conduct a field activity in which students participate in a whole-class Earth systems study to develop appropriate science inquiry skills and make connections with science as a human endeavour.

Investigate the many factors that limit predictions about the effects of combustion of fossil fuels on global warming.

The field sheet is built for the first: it follows the screens and has space for a local site. Screen 8 looks at the limits of a prediction for one lagoon; the Climate evidence lesson takes up climate models.

Science as a human endeavour runs through the lesson. Its key concepts in the outline include these, used in the screens shown:

Science informs public debate and is in turn influenced by public debate; at times, there may be complex, unanticipated variables or insufficient data that may limit possible conclusions.

Screen 7: the argument over hot-water washing, and the turtle and dolphin deaths after the X-Press Pearl, which have no established cause; screen 8: two published estimates of the flow that resets the South Lagoon.

The use of scientific knowledge may have beneficial or unexpected consequences; this requires monitoring, assessment, and evaluation of risk, and provides opportunities for innovation.

Screen 5: the barrages kept the Lower Lakes fresh for irrigation and changed the Coorong; screen 7: hot water removed oil and harmed shore life, which NOAA found by monitoring sites that were left uncleaned.

Collaboration between scientists, governments, and other agencies is often required in scientific research and enterprise.

Screen 7: the UN advisory mission to Sri Lanka in June 2021; screen 8: the Goyder Institute’s research on the 2022–23 flood for the Healthy Coorong, Healthy Basin program.

New technologies improve the efficiency of scientific procedures and data collection and analysis. This can reveal new evidence that may modify or replace models, theories, and processes.

Screen 6: an hourly tide gauge record and a fitted tide; screen 9: DEA Coastlines, Copernicus Browser and phone apps for field data.

The Earth systems study is assessed on IAE1 to IAE4, KA1 and KA4. SACE’s marking guide for the study puts every part of the proposal under IAE1, and divides the report between KA1 (purpose and background), IAE2 (collecting and presenting data), IAE3 (analysing the interactions of two or more spheres, and a conclusion with predictions or advice), IAE4 (limitations and improvements) and KA4 (terms, format and references). The lesson gives practice in IAE1 (screen 9), IAE2 (the tables on the field sheet), IAE3 (screens 4, 6 and 8, and the advice step on screen 9), IAE4 (screen 8: what limits the prediction), KA1 and KA2 (the checks and sorts), KA3 (screen 7) and KA4 (the notebook and the field sheet).

How the lesson is taught

The lesson follows research on systems thinking in Earth science. Ben-Zvi Assaraf and Orion (2005) described eight characteristics of systems thinking, using the water cycle, and found that junior high school students developed them in sequence. In their study about 70% of students could identify a system’s components and processes; about 50% could identify relationships and dynamic relationships between components; about 30 to 40% understood the system’s cyclic nature, organised components in a network of relationships and made generalisations; and 10 to 30% grasped the hidden components and could think in time, looking back at a system’s history and predicting its future. Later papers call this the System Thinking Hierarchical (STH) model, with three levels: analysis, synthesis and implementation (Assaraf, Dodick and Tripto, 2013). The SACE dot points follow the same skills, and so do the screens: components, visible and hidden (screen 2), relationships (screen 3), a network with feedback (screen 4), time and cycles (screens 5 and 6), and looking back and predicting (screens 7 and 8). The hidden layer on screen 2 and the push tool on screen 4 aim at the skills the students in that study found hardest.

Ben-Zvi Assaraf and Orion recommend inquiry-based learning and “Use of the outdoor learning environment for the construction of a concrete model of a natural system”, which is the job of the field sheet. In a quasi-experimental study with seventh graders, a month of work with systems tools, including causal loop diagrams, gave the experimental group “significantly better systems thinking and dynamic environmental problem solving skills” than a comparison group, although “standard science achievement did not improve at all” (Doganca Kucuk and Saysel, 2018). Eidin and others (2023) note that explaining behaviour through feedback “has been documented as particularly challenging for students”, and found that some of the Grade 10 students in their study “continue to favor linear causal explanations”. Screen 4 asks students to classify each loop and then follow a change round the web.

  • Timing. About four hours: five 50-minute lessons. Lesson 1: screen 1 together, then screens 2 and 3. Lesson 2: screens 4 and 5. Lesson 3: screens 6 and 7. Lesson 4: screen 8 and the field sheet. Lesson 5: screens 9 and 10. SACE’s integration grid shows how Topic 1 can instead be taught inside the other three topics, with most of its links in Topic 4, so you could also spread the screens through the year.
  • Pairs or alone. Screens 3 and 4 work well in pairs. Screen 9 is better done alone, since in the Earth systems study “Students work individually in their data collection and field or laboratory analysis, and preparation of reports for external assessment.”
  • Discussion points. After screen 4, ask which link in the web students would most like to measure, and how. After screen 6, ask which records could be predicted a year ahead. After screen 8, compare predictions: who chose which reset estimate, what evidence would settle the question, and what the rule leaves out.
  • A local site. The lesson uses the Coorong, but every box on the field sheet works for a creek, a beach, a park or the school grounds. If your class runs a whole-class field study, use the field sheet on the day and screen 9 to plan it.
  • The study itself. Screen 9 is practice. For the study, “Each student designs an investigation proposal” (subject outline), and SACE’s 2025 subject assessment advice says the more successful studies “investigated the student’s own topic rather than a topic specified by the teacher” and collected data over weeks to months. The less successful ones spent words on risks that did not apply, or moved the method into an appendix, which is not assessed. The combined word count for the proposal and report should be at most 2000 words if written. The steps on screen 9 for variables, equipment, secondary data and risks follow this advice.
  • The field sheet has six boxes, one for each screen or pair of screens: a table of components, an interaction table, space to draw a web, a table of scales, past and future, and a study plan. Collect it as evidence of learning.

Handle with care

  • The Coorong, Lower Lakes and Murray Mouth are Ngarrindjeri country. DEWNR (2014) names the Ngarrindjeri as “the traditional owners of the Coorong, Lower Lakes and Murray Mouth area”, and the Ramsar site information says “The area is central to aboriginal culture and spiritual beliefs.” The lesson gives these facts and the name Kurangk, and tells no Ngarrindjeri stories. If your class studies the area, follow your school’s protocols and, where you can, the guidance of the Ngarrindjeri Regional Authority.
  • The 2019–20 bushfires on screen 5 killed 33 people and destroyed more than 3,000 homes (Royal Commission, 2020). Some students may have been affected by them, or by drought or the 2022–23 flood on the River Murray. Keep the discussion on how the spheres interact.
  • The X-Press Pearl case involves animal deaths, lost livelihoods and legal proceedings that were still going on in 2026. Screen 7 gives each claim with its source and says that the cause of the deaths is not established. The ship’s operator has criticised the judgment (X-Press Pearl Information Centre, 2025), and in September 2025 it said that it and its insurer “cannot make the payment at this stage” (Ship & Bunker, 2025). Reports from 2026 describe criminal and civil proceedings against the ship’s local agent and a dispute over how the case has been handled (Daily Mirror, 2026); we could not confirm its current status.
  • The hazards on screen 9 are a starting point. South Australian Department for Education schools need a risk assessment that “must occur before the site leader gives approval”, under the Camps and excursions procedure.

Misconceptions the screens target

  • The water cycle starts and ends somewhere, and leaves out groundwater (screens 2 and 5, x1). In Ben-Zvi Assaraf and Orion’s study, about half the students still agreed after teaching that the water cycle has beginning and ending points. Groundwater was missing from about 60% of their drawings before teaching, and from about a third after it. Groundwater is 30.1% of Earth’s fresh water, and the residence-time chart shows water moving on from every store.
  • Earth systems are rocks, air and water, without living things (screen 2). Most students in the same study left plants, animals and people out of their drawings. The Coorong picture includes microbes, larvae and seeds.
  • Causes and effects run in a straight line (screen 4, q-web, x3). A change in the South Lagoon reaches Ruppia by two paths with opposite effects, and two loops push changes back or further.
  • Fresher water is always better for the Coorong (screens 4 and 8). Ruppia tuberosa’s target band is 60 to 100 g/L; in the 2022–23 flood the plants died off fully when salinity fell to 10 g/L, and lower salinities favour filamentous algae.
  • A clean-up always helps (screen 7, q-spill, x7). Shores washed with hot water declined more at first than oiled shores that were left alone.
  • A change has either a natural cause or a human one (screen 5, x4). The 1981 Mouth closure and the 2019–20 bushfires had both.
  • A change at a site has its cause at that site (screen 5, q-mangrove). The Gulf of Carpentaria mangroves died back in 2015–16 when the El Niño in the Pacific lowered the sea level in the Gulf.
  • A cycle repeats on a fixed timetable (screen 6). El Niño comes on average every 3 to 5 years, at irregular intervals; in most dry years river flow follows a regular monthly pattern only because people set the delivery schedule.
  • A prediction is a single number (screen 8, x8). The model gives a band, and two published reset estimates give very different futures for the same flows.
  • The Sun is part of the atmosphere (screen 2). It is outside the Earth system and drives it.

About the data and the models

  • The Coorong picture (screen 2) is a schematic cross-section of the South Lagoon, not to scale, and the parts on it are placed from the sources named in each answer. Lengths of the Coorong in the sources run from about 110 km to 140 km, probably measured between different points, so screen 2 says more than 100 km.
  • The Gulf of Carpentaria dieback (screen 5): Duke and others (2017) weigh drought, heat and low sea level together, while Abhik and others (2021) identify the fall in sea level as “the crucial factor”. The 7,400 hectares were 6% of the mangroves in the affected stretch of coast, not of Australia’s mangroves.
  • Sea level at Thevenard (screen 6): hourly Bureau of Meteorology data from the Australian Baseline Sea Level Monitoring Project, as packaged in the R package TideHarmonics (Stephenson, 2017), converted to the Australian Height Datum by subtracting 0.993 m, the value given by both the package and the Bureau’s station table. The predicted tide is our own least-squares fit of 68 tidal constituents to the 2012 to 2014 record (UTide). It explains 81.0% of the variance, and it is not a Bureau prediction; the gap between measured and predicted is our calculation, not the Bureau’s residual series. We found no source naming the weather behind the surge of 8 July 2014.
  • Temperature at Adelaide Airport (screen 6): the Bureau’s daily maxima for station 023034, as downloaded by the R package austemp (Russo), which ends on 1 April 2024. These are the station’s own values, not a series adjusted for changes of site or instrument. The record high of 45.8 °C on 24 January 2019 matches the Bureau’s annual summary, and the monthly averages agree with the Bureau’s station statistics to within 0.1 °C (our check).
  • River Murray flow (screen 6): the Bureau’s Water Data Online, station A4261001, River Murray at Calculated Flow to SA, monthly and daily means; months missing in the source are Feb 1977, Mar to May 2017, Jan, Mar and May 2026, and November 2026, the current month. The daily peak of the 2022–23 flood is 185,745 ML a day in the Bureau’s data (our conversion from 2,149.827 m³/s); DEW gives a peak of around 190 GL a day, and a daily mean is lower than the highest flow within the day. In the dry years from 2002 to 2006, 42 of 60 months were within 3% of the monthly entitlement schedule (our arithmetic), which is the regular pattern people set.
  • Flow and salinity, year by year (screen 8): barrage flows to 2018/19 from Ye and others (2020), then from DEW’s River Murray Flow and Use Reports and Water for the Environment Report. We found no totals for 2013/14 or 2014/15; DEW (2021) gives an average of 1,524 GL a year for the calendar years 2013 to 2015. The 2022/23 figure covers July 2022 to March 2023 only. We found no continuous South Lagoon salinity series, so the chart shows the yearly ranges in monitoring reports. Salinity in psu, ppt and g/L is about the same.
  • The prediction model (screen 8) is a rule of thumb, not one of the Coorong’s hydrodynamic models. It starts at 55 g/L, because the South Lagoon stayed below 60 g/L for most of 2023 (Goyder Institute, 2024c); adds 11 to 16 g/L in each year without a resetting flow, the rise DEW (2021) reports between high flows; and resets to 50 g/L, near the 43 g/L of January 2023. Flows are grouped as low (under 3,000 GL), medium (3,000 to 10,000 GL) and flood (over 10,000 GL). With the “more than 10,000 GL” setting a medium year holds salinity steady: that part is our assumption. The 5% evaporation setting is the 2050 scenario in DEW (2021). The two reset estimates were written for slightly different goals: Taylor (2010) gives the flow that would match a planned pumping scheme, and DEH (2010), citing Paton and others (2009), the flow that would restore target salinities.
  • Residence times (screen 5) are from Earle (2023), Table 11.1.1. Other sources give different values: NOAA 9 to 10 days for the atmosphere, a 2017 study 8.9 ± 0.4 days (van der Ent and Tuinenburg), and the Science Learning Hub 14 to 28 days for soil moisture and 40 to 400 years for glaciers. Some of the difference comes from what each source counts as a store.
  • The oil spill (screen 7): where the oil went is the estimate of Wolfe and others (1994), as given by the Exxon Valdez Oil Spill Trustee Council. Sources give the volume as 10.8 to 11 million US gallons and the oiled shoreline as 1,000 to 1,300 miles; the page uses the Trustee Council’s figures and converts them (1 US gallon = 3.785 L; 1 mile = 1.609 km). The X-Press Pearl’s pellets are given as about 1,680 tonnes (UNEP, 2021), about 1,500 tons (WHOI) and 78 tonnes (one 2025 news report); the page uses UNEP’s figure. Counts of dead animals rose over time: 176 turtles by 7 July 2021, 251 by 17 July, and 417 in a 2025 report. The latest court news we found is from January 2026, when the Attorney General’s Department told the Supreme Court that it had taken steps to begin criminal and civil proceedings against the ship’s local agent (Daily Mirror, 2026).
  • Where the sources disagree, the page or these notes say so. The 1981 Mouth closure: “completely close” in Mosley, Gibbs and Zampatti (2024) and “almost physically closed” in Higham (2012), so the page says the sand blocked the Mouth, as the newspaper record does. Water use upstream: CSIRO (2008) gives a 61% cut in flow at the Mouth, and Mosley, Gibbs and Zampatti (2024) say that before the Basin Plan the flow over the barrages was 41% of the natural flow, which is close. The 2022–23 flood: “the largest flood event since 1956” (DEW’s Flow and Use Report for October to December 2022) and “the second largest on record, only surpassed by the 1956 flood” (Goyder Institute, 2024a). Life underground: about 70% of Earth’s bacteria and archaea (Deep Carbon Observatory, 2018) or about 15% of all biomass (Bar-On and others, 2018). Heat from Earth’s interior: 47 TW (Davies and Davies, 2010) or about 44 TW (Lawrence Berkeley National Laboratory, 2011).

Answers at a glance

  • Screen checks: q-spheres, groundwater is water out of sight but about 30% of Earth’s fresh water; q-links, Hydrosphere row, Atmosphere column; q-web, two paths push Ruppia opposite ways, so the result depends on how strong each link is; q-scales, Mount Pinatubo; q-mangrove, drought, heat and a fall in sea level linked to El Niño; q-patterns, nothing yet, because dissolved oxygen follows a daily cycle; q-spill, telling the effects of the oil from the effects of the clean-up; q-coorong, about 3,000 GL; q-study, the landholder’s permission.
  • The Coorong picture: Southern Ocean, lagoon water, groundwater, salt and water in the mud are hydrosphere (salt, groundwater and the water in the mud may add geosphere); dunes, mud and soil are geosphere (mud may add biosphere and hydrosphere, soil all three others); dune plants, Ruppia, waterbirds, seeds and turions, larvae and microbes are biosphere; clouds and water vapour are atmosphere, hydrosphere or both; the Sun is none of the four.
  • The interaction table (from the row to the column): atmosphere to geosphere, wind builds the dunes; hydrosphere to geosphere, waves carry sand into the Mouth; hydrosphere to atmosphere, evaporation; atmosphere to hydrosphere, hot dry weather concentrates the salt; hydrosphere to biosphere, salinity makes it harder for seeds to sprout; biosphere to biosphere, algae shade Ruppia; biosphere to geosphere, rotting algae and dredging; geosphere to hydrosphere, acid lake sediments; geosphere to biosphere, mudflats feed shorebirds; hydrosphere to hydrosphere, winter sea level. Six boxes stay empty: geosphere to geosphere, geosphere to atmosphere, atmosphere to atmosphere, atmosphere to biosphere, biosphere to atmosphere and biosphere to hydrosphere.
  • The web: river flow lowers salinity (−) and sand in the Mouth (−); evaporation raises salinity (+); salinity lowers Ruppia (−) and algae (−); algae lower Ruppia (−) and shorebird feeding (−); Ruppia raises seeds and turions (+) and they raise Ruppia (+); sand raises dredging (+) and dredging lowers sand (−). The sand and dredging loop is balancing; the Ruppia and seed loop is reinforcing. Pushing river flow down raises salinity and sand, cuts algae and gives Ruppia a mixed result.
  • Time and space: lightning, seconds to days and local (natural); the 2019–20 bushfires, weeks to a few years and continental to global (both); Pinatubo, weeks to a few years and global (natural); El Niño, weeks to a few years and continental to global (natural); the yearly carbon dioxide cycle, weeks to a few years and continental to global (natural); rising carbon dioxide, decades to centuries and global (human); ice ages, thousands of years or more and global (natural); the Himalaya, thousands of years or more and regional to continental (natural); the 1981 Mouth closure, weeks to a few years and local to regional (both); the barrages, weeks to centuries and regional (human); dryland salinity, decades to centuries and local to regional (human).
  • Patterns: sea level over two days and one month, a regular cycle; the tide and surge, irregular events; temperature over one month, irregular events; over three years, a regular cycle; 1956 to 2023, a trend; river flow over four months and 1977 to 2026, irregular events.
  • Clean-up methods: booms and skimmers, and picking and sieving pellets, take the pollution out; dispersants, burning and hot-water washing move it somewhere else; fertiliser and leaving the shore alone let it break down naturally.
  • The prediction model, with evaporation as now: repeating 2012/13 to 2023/24 gives 0 to 1 of 12 years above 100 g/L with about 3,000 GL, but 4 to 7 years with more than 10,000 GL, the low estimate staying above 100 g/L from 2030 to 2033. A medium year every third year never passes 100 g/L with about 3,000 GL, but passes it in 6 to 9 years with more than 10,000 GL. Twelve dry years give 8 to 10 years above 100 g/L with either setting, ending at about 190 to 250 g/L in 2035.
  • Exit check: x1 Ruppia seeds and turions, biosphere; x2 wind builds the dunes; x3 reinforcing, so a low seed bank keeps recovery slow; x4 both natural and human-induced; x5 the ice ages; x6 the times of high tide; x7 a steeper path to recovery; x8 give a range and state the assumptions; x9 the calibrated EC meter at three sites with rainfall records.

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References

  • Abhik, S., and others (2021). Influence of the 2015–2016 El Niño on the record-breaking mangrove dieback along northern Australia coast. Scientific Reports, 11, 20411.
  • Alaska Department of Environmental Conservation (1993). The Exxon Valdez oil spill: Final report, State of Alaska response, Chapter 2: Technology.
  • Anthony, M. A., Bender, S. F., & van der Heijden, M. G. A. (2023). Enumerating soil biodiversity. Proceedings of the National Academy of Sciences, 120(33), e2304663120. https://doi.org/10.1073/pnas.2304663120
  • Assaraf, O. B.-Z., Dodick, J., & Tripto, J. (2013). High school students’ understanding of the human body system. Research in Science Education, 43(1), 33–56. https://doi.org/10.1007/s11165-011-9245-2
  • Australian Bureau of Statistics (2002). Measuring Australia’s Progress, 2002 (1370.0), Land degradation.
  • Bar-On, Y. M., Phillips, R., & Milo, R. (2018). The biomass distribution on Earth. Proceedings of the National Academy of Sciences, 115(25), 6506–6511. https://doi.org/10.1073/pnas.1711842115
  • Baruch, Z., Caddy-Retalic, S., Guerin, G. R., Sparrow, B., Leitch, E., Tokmakoff, A., & Lowe, A. J. (2018). Floristic and structural assessment of Australian rangeland vegetation with standardized plot-based surveys. PLoS ONE, 13(9), e0202073.
  • Ben-Zvi Assaraf, O., & Orion, N. (2005). Development of system thinking skills in the context of earth system education. Journal of Research in Science Teaching, 42(5), 518–560. https://doi.org/10.1002/tea.20061
  • Brookes, J., Dalby, P., Dittmann, S., O’Connor, J., Paton, D., Quin, R., Rogers, D., Waycott, M., & Ye, Q. (2018). Recommended actions for restoring the ecological character of the South Lagoon of the Coorong (Technical Report 18/04). Goyder Institute for Water Research.
  • Brookes, J. D., Huang, P., Zhai, S. Y., Gibbs, M. S., Ye, Q., Aldridge, K. T., Busch, B., & Hipsey, M. R. (2022). Environmental flows to estuaries and coastal lagoons shape the salinity gradient and generate suitable fish habitat: Predictions from the Coorong, Australia. Frontiers in Environmental Science, 10, 796623.
  • CSIRO (2008). Water availability in the Murray-Darling Basin. A report to the Australian Government from the CSIRO Murray-Darling Basin Sustainable Yields Project.
  • Davies, J. H., & Davies, D. R. (2010). Earth’s surface heat flux. Solid Earth, 1, 5–24. https://doi.org/10.5194/se-1-5-2010
  • Department for Environment and Heritage (2010). Technical feasibility assessment: Pumping hypermarine water out of the Southern Lagoon of the Coorong. Government of South Australia.
  • Department for Environment and Water (2022). Guide to climate projections for risk assessment and planning in South Australia 2022. Government of South Australia.
  • Department for Environment and Water (2023a). Ecological Character Description 2015: The Coorong and Lakes Alexandrina and Albert Wetland. Government of South Australia.
  • Department for Environment and Water (2023b). The flood of a generation (news article). Government of South Australia.
  • Department of Environment, Water and Natural Resources (2013). Information sheet on Ramsar wetlands: The Coorong, and Lakes Alexandrina and Albert Wetland. Government of South Australia.
  • Doganca Kucuk, Z., & Saysel, A. K. (2018). Developing seventh grade students’ understanding of complex environmental problems with systems tools and representations: A quasi-experimental study. Research in Science Education, 48(2), 491–514. https://doi.org/10.1007/s11165-017-9620-8
  • Duke, N. C., and others (2017). Large-scale dieback of mangroves in Australia’s Gulf of Carpentaria: a severe ecosystem response, coincidental with an unusually extreme weather event. Marine and Freshwater Research, 68, 1816–1829.
  • Earle, S. (2015). 10.5: Mechanisms for plate motion. In Physical Geology. BCcampus.
  • Earle, S. (2023). 11.1: The hydrologic cycle. In Environmental Geology. Geosciences LibreTexts.
  • Eidin, E., Bowers, J., Damelin, D., & Krajcik, J. (2023). The effect of using different computational system modeling approaches on applying systems thinking. Frontiers in Education, 8, 1173792. https://doi.org/10.3389/feduc.2023.1173792
  • Engineering Heritage South Australia (2009). River Murray Barrages: Award of National Engineering Landmark (ceremony report).
  • Environment Protection Authority South Australia (2007). EPA guidelines: Regulatory monitoring and testing, water and wastewater sampling.
  • Goyder Institute for Water Research (2024a). Response of the Coorong: Sediment (Project Highlights fact sheet, Healthy Coorong, Healthy Basin).
  • Goyder Institute for Water Research (2024b). Response of the Coorong: Water quality (Project Highlights fact sheet, Healthy Coorong, Healthy Basin).
  • Goyder Institute for Water Research (2024c). Response of the Coorong to the 2022–2023 River Murray flooding (summary placemat; no date shown, published online November 2024).
  • Higham, J. S. (2012). An analysis of MDBA modelling outputs for the draft Basin Plan: Hydrodynamic modelling of the Coorong and Murray Mouth (DENR Technical Report). Department of Environment and Natural Resources, Adelaide.
  • Incardona, J. P., Carls, M. G., Holland, L., Linbo, T. L., Baldwin, D. H., Myers, M. S., Peck, K. A., Tagal, M., Rice, S. D., & Scholz, N. L. (2015). Very low embryonic crude oil exposures cause lasting cardiac defects in salmon and herring. Scientific Reports, 5, 13499. https://doi.org/10.1038/srep13499
  • James, B. D., Reddy, C. M., Hahn, M. E., Nelson, R. K., de Vos, A., Aluwihare, L. I., Wade, T. L., Knap, A. H., & Bera, G. (2023). Fire and oil led to complex mixtures of PAHs on burnt and unburnt plastic during the M/V X-Press Pearl disaster. ACS Environmental Au, 3(5), 319–335. https://doi.org/10.1021/acsenvironau.3c00011
  • Jewell, S. A., Fortunato, A., & Walker, D. (2011). Generation of flood dominance in a mixed tidal system: A numerical investigation of the Murray Mouth. Coasts & Ports 2011, Perth.
  • Khaykin, S., Legras, B., Bucci, S., Sellitto, P., and others (2020). The 2019/20 Australian wildfires generated a persistent smoke-charged vortex rising up to 35 km altitude. Communications Earth & Environment, 1, 22. https://doi.org/10.1038/s43247-020-00022-5
  • Kingsford, R. T., Walker, K. F., Lester, R. E., Young, W. J., Fairweather, P. G., Sammut, J., & Geddes, M. C. (2011). A Ramsar wetland in crisis: The Coorong, Lower Lakes and Murray Mouth, Australia. Marine and Freshwater Research, 62(3), 255–265. https://doi.org/10.1071/MF09315
  • Lester, R. E., Fairweather, P. G., Webster, I. T., & Quin, R. A. (2013). Scenarios involving future climate and water extraction: Ecosystem states in the estuary of Australia’s largest river. Ecological Applications, 23(5), 984–998.
  • Miller, A., & Gibbs, M. (2021). Initial hydrodynamic model scenarios to inform Coorong Infrastructure Investigations project (DEW Technical Report 2021/10). Department for Environment and Water. Cited on the page as DEW (2021).
  • Mosley, L. M., and others (2014). Acidification of lake water due to drought. Journal of Hydrology, 511. https://doi.org/10.1016/j.jhydrol.2014.02.001
  • Mosley, L. M., Dittmann, S., Ye, Q., and others (2024). South Australian Murray-Darling Basin 2022–2023 flood environmental response in the Coorong (Technical Report 2024/02). Goyder Institute for Water Research.
  • Mosley, L. M., Gibbs, M., & Zampatti, B. P. (2024). The past, present and future of the Coorong, Lower Lakes and Murray Mouth. In Radcliffe and Flapper (eds), A thriving Murray-Darling Basin in 50 years (pp. 151–166). Australian Academy of Technological Sciences and Engineering.
  • Mosley, L. M., Priestley, S., Brookes, J., and others (2020). Coorong water quality synthesis with a focus on the drivers of eutrophication (Technical Report 20/10). Goyder Institute for Water Research.
  • Native Vegetation Council (2024). Bushland Assessment Manual. Department for Environment and Water.
  • Paton, D. C., & Bailey, C. P. (2012). Annual monitoring of Ruppia tuberosa in the Coorong region of South Australia, July 2011. University of Adelaide.
  • Paton, D. C., Paton, F. L., & Bailey, C. P. (2017). Monitoring of Ruppia tuberosa in the southern Coorong, summer 2016–17. University of Adelaide.
  • Royal Commission into National Natural Disaster Arrangements (2020). Report.
  • Stephenson, A. (2017). TideHarmonics: Harmonic analysis of tides (R package version 0.1-1).
  • Tang, W., Llort, J., Weis, J., Perron, M. M. G., Basart, S., and others (2021). Widespread phytoplankton blooms triggered by 2019–2020 Australian wildfires. Nature, 597, 370–375. https://doi.org/10.1038/s41586-021-03805-8
  • Taylor, B. (2010). Ecological justification for the South Lagoon Salinity Reduction Scheme: A discussion paper. Department of Environment and Natural Resources, Adelaide.
  • UNEP and UN OCHA (2021). X-Press Pearl maritime disaster, Sri Lanka: Report of the UN Environmental Advisory Mission.
  • van der Ent, R. J., & Tuinenburg, O. A. (2017). The residence time of water in the atmosphere revisited. Hydrology and Earth System Sciences, 21(2), 779–790. https://doi.org/10.5194/hess-21-779-2017
  • Webster, I. T. (2010). An evaluation of three management strategies for the mitigation of high salinities in the Coorong. CSIRO Water for a Healthy Country Flagship.
  • Wolfe, D. A., and others (1994). The fate of the oil spilled from the Exxon Valdez. Environmental Science & Technology, 28(13), 560A–568A. https://doi.org/10.1021/es00062a712
  • Ye, Q., Bucater, L., Short, D., & Giatas, G. (2020). Coorong fish condition monitoring 2008−2019: Black bream, greenback flounder and smallmouth hardyhead populations (SARDI Research Report Series No. 1066).

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Word list