6) Oceans on the Edge

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Useful Links
Useful artilce on the possible extinction of Coral Reefs
A summary of two ocenas in 2050 - links with article above
Interactive site on Coral Reefs:
Guardian article where the WWF warns on danger to Coral Reefs
More detail on mangrove swamps:
Interactive marine food web:


Create an ocean food web:

      www.vtaide.com/png/foodchanins.htm and www.vtaide.com/png/oceanweb2.htm 

Key Words

Aqua culture – commercial fish farming, e.g. rearing fish prawns in ponds of submerged cages

Biodiversity – the number and variety of living species found in a specific area
Bleaching – degradations of coral reefs under conditions of increased acidity in seawater
Climate change – long term changes in temperature and precipitation
Continental shelf – the submerged edge of a continental land mass
Coral reef – a hard stony ridge, just above or below the surface of the sea, formed by the external skeletons of millions of tiny creatures called polyps.
Estuaries – a river mouth that is wide and experiences tidal conditions
Eutrophication – the loss of oxygen in water after too much nutrient enrichment has taken place
Extinction – the permanent loss of something, generally used with reference to species of plants or animals, when there are no living examples left
Food web – an illustration of the of the grouping of animals and plants found in an ecosystem, showing the sources of food for each organism
Habitat – an animal or plant’s natural home
Mangrove swamp – a tidal swamp dominated by mangrove trees and shrubs that can survive salty and muddy conditions found along tropical coastlines
Marine ecosystem – the web of organisms that that live in the ocean or a part of the ocean
Nutrient cycle – a set of process whereby organisms extract minerals necessary for growth from soil or water, before passing them on through the food chain – and ultimately back into the soil and water.
Overfishing – taking too many fish (or other organisms) from the water before they have had time to reproduce and replenish stocks for the next generation
Pollution – the presence of chemicals, noise, dirt or other substances which have a harmful or poisonous effect on an environment
Run-off – water that flows directly over land towards the sea or rivers after heavy rainfall
Sea level rise – the increase in the level of the sea, relative to the land
Siltation – the deposition of silts (sediments) in rivers and harbours
Sustainability – the ability to keep something going at the same rate or level.  From this stems the idea that the current generation of people should not damage the environment in ways that will threaten future generations’ environment.
Unsustainable – unable to be kept going at the same rate or level
At the end of this unit you should...
- What different types of marine ecosystems there are

- The distribution of marine ecosystems globally

- How humans use mangrove swamps for resources
- Which human activities, like overfishing, are degrading marine ecosystems
- How these human activities can lead to damage and destruction
- What nutrient cycles are and food webs
-How humans can damage marine food webs and nutrient cycles
- How climate change might change marine ecosystems
- That marine ecosystems are under increasing pressure
- How this pressure affects ecosystems locally, such as Firth of Clyde
- Why, locally, people’s views on ecosystems can lead to conflict
- What sustainable management means
- How sustainable management can protect ecosystems
- How global actions such as CITIES and the IWC can help improve sustainability
Luke Kemish,
28 Feb 2010, 01:57