Global Citizenship -
Marine Environment

Global Citizenship – Marine Environment is a maintenance theme that will enable you to discover how your work on the Green-Schools programme has positively influenced environments worldwide while focusing your work on our oceans and seas.

Global Citizenship Marine Environment is the eighth theme of the Green-Schools programme. As with the previous themes, you will see that this theme cross-cuts and integrates with previous themes in many ways. 


Why Global Citizenship Marine Environment?

As with the other Global Citizenships themes, Global Citizenship Marine Environment will enable you to discover how your work on the Green-Schools programme has, positively, influenced people and their local environments worldwide while focusing your work on our oceans and seas. 

This time we are asking schools to look at Global Citizenship in relation to the Marine Environment. Although we have named five oceans, they are all part of one large global ocean. The ocean contains unique biodiversity, provides valuable food resources and is a major sink for anthropogenic carbon. As an island, Ireland has a close connection with the Atlantic Ocean. Did you know that Ireland’s seabed territory is one of the largest in Europe and more than 10 times Ireland’s land mass? That’s a lot of ocean to protect, and that is exactly what we all need to do. As you worked on the themes of Water and Biodiversity before you will understand the importance of water and ecosystems; the marine environment is another very important ecosystem. Your school does not need to be a coastal school to take part. Through your work on this theme, you will discover the importance the marine environment plays in all our lives. We will be asking you to identify the threats to the Marine Environment with a particular focus on Marine Litter. 


Why is the Marine Environment so important and why should we conserve it?

When we speak about the marine environment it encompasses a vast variety of coastal and marine ecosystems which create very diverse habitats with many different plant and animal species adapted to live in these habitats. A few examples: 

  • Estuaries – a fantastic habitat for our wintering wading birds as they provide a huge source of food for them
  • Lagoons – a very special habitat that supports species adapted to live in semi saline/brackish waters
  • Coral reefs – supports a huge variety of biodiversity through offering food shelter and highly protected breeding grounds
  • Mangroves – highly specialised salt tolerant trees that are adapted to live in harsh coastal conditions in tropical and sub-tropical areas.
  • Intertidal zones – also known as foreshore or seashore is an area that is above water at low tide and under water at high tide. This area can include many different types of habitats, with many types of animals, such as starfish, sea urchins, and numerous species of coral. This habitat creates extremely harsh conditions and supports a variety of organisms adapted to live in this harsh climate.
  • Open ocean – Where we can see our most beautiful species of whales, dolphins and sharks
  • Deep sea bed – Very specialised species live in and on the deep sea bed, most feed on detritus that sinks to the seabed and these species are thus extremely important to the cycling of nutrients in our oceans, just like the animals that live in your compost bin!

Marine ecosystems are amongst the most productive ecosystems in the world. Apart from providing us with a basic intrinsic value, marine ecosystems give us products such as seafood, fertilisers, sand, oil, medicine, they help to maintain ecological diversity, regulate climate change, provide employment, are an important part of the shipping industry. The coast provides us with fantastic places to relax in; who doesn’t enjoy building sandcastles, watching birds swoop around sea cliffs or swimming through the waves?


Threats to the Marine Environment

  1. Marine Litter and Pollution 
  2. Overfishing 
  3. Climate Change 
  4. Invasive Species 
  5. Commercial Shipping 
  6. Offshore Mining 


Marine Litter

Marine litter is any man-made material that has ended up in the marine environment after being lost or discarded at sea or on land. Approximately 10 million tonnes of litter end up in the world’s oceans and seas each year. The term ‘marine litter’ covers a range of materials which have been deliberately discarded, or accidentally lost on shore or at sea, and it includes materials that are carried out to sea from land, rivers, drainage and sewerage systems, or the wind. (European Commission, 2013). 

What we find on our beaches is not the full extent of the marine litter load in the environment. It is estimated that 70% of marine litter is on the seabed and 15% is what we find on our shores (OSPAR, 1995). Marine litter consists of a wide range of materials, including plastic, metal, wood, rubber, glass and paper. However, it is dominated by plastic which accounts for 80% of the items found on our beaches. 


Why is marine litter harmful to the environment?

There are many reasons why marine litter is harmful to the environment. Here are some examples: 

  • Marine litter can become a health and safety issue for beach users, e.g. broken bottles, food packaging, may attract rats. 
  • Plastics do not decompose. They break into smaller pieces over time and are ingested by wildlife. 
  • Microplastics carry toxins which wildlife may ingest causing harm to them and us as they end up in our food chain. 
  • Floating debris can carry invasive species. 
  • Larger marine debris can crush sensitive habitats, such as coral reefs and sea grass. 

Marine wildlife can:

  • Ingest plastics causing blockages in the digestive system resulting in malnutrition and/or starvation. 
  • Be poisoned by plastic as it absorbs chemical pollution in the sea 
  • Suffocate by swallowing or being covered by plastic bags (e.g. sea turtles eat plastic bags which can be mistaken for jellyfish. 
  • Become entangled in fishing nets and ropes 


Climate Change and the Marine Environment

The ocean covers 70% of our earth’s surface and it contains 97% of all the water on earth. The marine environment plays a very important role in maintaining our Climate. It helps soak up energy (heat) and distribute it more evenly around the earth. It also soaks up carbon dioxide (CO2) and has been responsible for slowing down the warming of the planet caused by man-made CO2 emissions. In fact, scientists maintain that at least one quarter of the CO2 released by the burning of fossil fuels (coal, oil and gas) is dissolved into the oceans saving us from living on an even warmer planet by acting as a carbon sink. 

The ocean does an excellent job of absorbing excess heat from the atmosphere. So, as our planet warms, the oceans get most of the extra energy. The downside is that if the oceans get too warm the plants and animals that live in it must adapt to these warmer waters or they will die. Another unfortunate result of the oceans absorbing this excess CO2 is that it becomes more acidic which also has devastating effects on marine wildlife. The rise in sea surface temperatures is also likely to causing more extreme weather events such as storms and hurricanes. 

 Even if you never have the chance to see or touch the ocean, the ocean touches you with every breath you take, every drop of water you drink, every bite you consume. Everyone, everywhere is inextricably connected to and utterly dependent upon the existence of the sea. Sylvia Earle

Now is the time to take action! As a global citizen, we are responsible for the health of our oceans. Let’s dive into this theme and explore the marine environment, its importance and find out what we can do to protect it. 



The Global Citizenship Marine Environment theme is supported by the Marine Environment section of the Department of Housing, Local Government and Heritage. The Marine Environment section of the department aims to protect Ireland’s marine and coastal habitats. They do this by implementing national, European and international policy focusing on maintaining or achieving the good environmental status of our seas and oceans. The aim is to ensure our seas are clean, healthy, and productive. Having healthy and functioning ocean ecosystems is vital for protecting public health, preserving our environment, and supporting Ireland’s economy. 

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