Seagrasses are an unsung hero of the Australian shoreline. They are flowering plants unlike many of the seaweeds that you find along the tide line. A long time ago they were plants living on the land and eventually made their way into the shallow sea in the same way that the ancestors of some animals like whales, seals and penguins did.
Since seagrasses are flowering plants they have true leaves, roots and flowers. They need sunlight to make food so they only survive in the shallow seas. There are 57 species around the world and over 30 live under Australian waters.
Seagrasses help to protect the coastline by softening the surge of the waves. They are often described as 'food factories'. Bacteria busy breaking down the seagrass leaves provide lots of food for plankton, nursery fish and other small marine animals. However larger animals that eat seagrass are black swans, dugong and turtles. Many of the fish we eat need to spend some of their time as they grow in these seagrass meadows.
If you want to know more about the seagrasses that grow around Australia you can see some of the different types on the following webpages:
If it is hard to find a biscuit tin to make your seagrass porthole, you might like to consider an aluminium pie tin.