Cyclones and the affects on Marine Life Year 6 Science Unit 3 Lesson 6 - 8

How do Cyclones Affect Marine Life? Cyclones affect marine life in a number of ways Heavy rainfall flows into coastal rivers and creeks causing mudslides, landslides, with silt, rubbish and sediment polluting the sea.

Our Coastline Heavy seas cause erosion along the coastline affecting beach dwelling marine creatures and others who nest on the beach such as turtles. Huge amounts of sand are displaced, creating new sand hazards in the sea, and washing away beaches.

Deep Water Dwellers In deep water, the seas get stirred as if with a giant spoon with colder saltier water from the depths coming to the top. Reduced amounts of dissolved oxygen, rapid salinity changes, and wave action kill marine life in this zone.

Shallow Water Dwellers In shallow water, the vast amount of rainwater deposited on top of the sea heavily reduces salinity – virtually changing the sea from salt water to fresh. Fish and marine animals asphyxiate due to lack of oxygen.

Slow to Recover Unlike the land which recovers quickly once the cyclone has passed, water can remain turbulent for up to a week after the cyclone finishes and can extend 100m below the surface.

Choking to Death Cyclonic turbulence strips coral reefs of vegetation, and choke them with debris, as well as hindering the light penetrating the surface necessary for the survival of coral due to hazy, dirty water.

Food Stock Depletion Damaged feeding grounds, such as seagrass beds, result in marine animal starvation and death.

How can we Minimise Damage? The best way we can help minimise the damage caused by cyclones is to vegetate our river banks. Planting halts erosion and saves dirt and silt washing downstream. Collection of waste from storm water drains also stops rubbish from being washed into the sea.

Clean Marine Starts with Us We cant control the weather, but we can help preserve the environment and ensure the creatures of Moreton Bay live in conditions best suited to their future survival.