Contents

Activity suggestions:

1. Ecosystem services

All ecosystems provide us with something called ‘ecosystem services’.

Temperate reefs, simply by existing, provide us with by-products that help us to survive.

The Reef Watch website says (http://www.reefwatch.asn.au/whyConserve.html):

Ecosystem services can be loosely defined as all the activities and functions that an ecosystem performs naturally. In particular the near shore oceanic environment provides us with food and other resources while at the same time absorbing many of our waste products including sewage and other pollutants.

The range of services carried out by marine ecosystems is too extensive to cover here, however a recent South Australian Government report attempted to put a dollar value on ecosystem services and drew the following conclusion:

The estimated value of ecosystem services carried out by marine communities within South Australian waters was in excess of $24.5 billion per year!

A large proportion of this is services carried out by reef and seagrass communities. These services are carried out by our marine environment free of charge and often without our knowledge.

Roughly grouped, some basic ecosystem services could be listed as:

• Food, medicine & material (e.g. wood, cotton) production

• Clean air

• Clean water

• Oxygen production

• Nutrient cycling (carbon and nitrogen in particular)

Using these websites as a starting point, get your students to undertake a research project to find out about the different kinds of ecosystem services. Are there different ones for the land and water? What is the significance of ecosystem services to humans? Why is it important that we retain healthy ecosystems to provide us with ecosystem services?

http://www.actionbioscience.org/environment/esa.html

http://www.amonline.net.au/factSheets/ecosystem_services.htm

2. Climate science

What are the ‘greenhouse gases’? How long do they persist in the atmosphere? How potent are they - for example, methane is 60 times more effective at trapping heat than CO2, but it breaks down more quickly. Where do they come from? What are the layers of the atmosphere?

Find out about how climate change will affect Australia.

Useful websites:

http://www.ipcc.ch

http://www.bom.gov.au/climate/change/

http://www.dar.csiro.au/information/climatechange.html

http://www.greenhouse.gov.au/impacts/overview.html

http://www.theweathermakers.com/learn/ (excellent school resources)

3. Anthropogenic threats to reefs

A recent report stated that ‘the most obvious human impacts threatening reefs include turbidity and sedimentation, nutrient enrichment, opportunistic and exotic taxa, climate change, toxicants and extractive resource use (e.g. fishing).’

a) Sedimentation is covered here

b) Exotic taxa, also known as introduced marine pests are covered here?

c) Nutrient enrichment is a polite way of saying that humans put too many nutrients in the water, which cause problems, particularly for marine plants. The two nutrients that create the most difficulties are nitrogen and phosphates. Both of these are common elements of land-based fertilisers and act as fertilisers when they wash into aquatic ecosystems, fresh or salt water. They are also found in chemicals such as laundry detergents and washing-up liquid and are difficult to remove during the waste water treatment process before the cleaned waste water is sent out to sea. Try testing some of these to find levels of nitrates/nitrites and phosphates.

For information about a free field trip to a waste water treatment plant, see the SciWorld website

In the last few years some Adelaide marine scientists have been experimenting with deliberately enriching areas of the sea with small amounts of nutrients to see what effect this had on the macroalgae. To find out more about this experiment, go here. This experiment has clear variables and results, it is a good paper for using as an example of a simple experiment.

d) Toxicants are chemicals that persist in the environment and are toxic even at low concentrations. Some of these chemicals bind to fats leading to bioaccumulation in top predators such as dolphins. Filter feeders are at high risk of having high concentrations of toxicants because they filter large quantities of water and accumulate the toxins. Examples include polychlorinated biphenyls (PCBs) and heavy metals such as copper, zinc, lead and mercury.

e) Fishing is covered in Maths.

-- GregCollings - 06 Oct 2008