Our unloved backyard

Lesson overview

This is the first of a two-lesson focus on the continental shelf seascape and associated water column. This lesson focuses on the commercial uses of the continental shelf and the potential impact of human activity on this area of the ocean.

Learning outcomes
  • Understand why the continental shelf is a special part of the ocean
  • Explore the useful things we get from the continental shelf
  • Consider how using the continental shelf for money can sometimes cause problems for nature
  • Research real-life examples of how humans use the continental shelf and the impacts
Lesson steps

1. Introduction to the Continental Shelf (10 minutes)

Introduce the learning objectives for the lesson using slide 2. Then use the slideshow to explain that the continental shelf is an underwater landmass that surrounds continents and islands, extending from the shore to the deep ocean, showing the bathymetric map on slide 4. Most people are familiar with the coastal environment and deep oceans, but the continental shelf often goes overlooked, despite its importance to humans and coastal nations. Slide 5 then shows how the continental shelf relates to countries’ Exclusive Economic Zone (EEZ) the area of the ocean and seabed that nations can exploit commercially.

Slides 6 to 9 then show how including the ocean in our idea of the UK is important, potentially increasing the UK’s area by 28 times. Use slide 10 to show the UK’s territorial seas in purple and the outline of the UK EEZ in red. Explain to students that the normal limit of an Exclusive Economic Zone is 200 nautical miles. This can be shortened where two countries’ EEZs would overlap and an agreed boundary is made. It can also be extended, with the UK claiming that a small rocky island, Rockall, should be part of the UK and decide its EEZ (see tiny writing to the right of the west coast of Scotland.

With the mention of overseas territories on slide 9, show the EEZ map again on slide 11 to demonstrate this with St Helena and Ascension Island as examples of UK Overseas Territories in the middle of the Atlantic between the coast of West Africa and Brazil.

2. Uses of the continental shelf (10 minutes)

This section looks at why the continental shelf is so important to nations. It is the area close to shore and not too deep where a lot of commercial activity takes place. Run through the diagram on slide 13 and then hand out Student Sheet Continental shelf resources & uses. Ask students to categorise the different resources and uses, as well as underlining any activities or resources that could be harmful to the ocean environment.

The continental shelf provides numerous resources and services, including:

  • Food: Fish, shellfish, and seaweeds
  • Energy: Fossil fuels and renewable energy sources
  • Minerals and building materials: Mined from the seabed or precipitated from seawater
  • Shipping transport: Utilizing surface waters for international trade
  • Undersea telecommunications: Fibre optics and cables placed on the seafloor
  • Carbon sequestration: Helping to combat global climate change
  • Providing diverse habitats: Supporting a variety of marine life, both in the water column and on the seafloor

There can be conflicts between economic and environmental uses of the continental shelf. Due to their remote location, these areas can be vulnerable to over-exploitation, disruption, and damage. Understanding this environment is essential for managing these conflicts and protecting marine ecosystems. Discuss the importance of the continental shelf and potential conflicts between economic exploitation and environmental conservation.

3. Fishing and marine biology (10 minutes)

Commercially important fish species rely on nutrient-rich waters, which can be influenced by ocean currents. This section explores a series of maps and videos focusing on fisheries and their connection to the continental shelf habitat.

Historically, most coastal cultures harvested the sea at a small scale, allowing resources to recover. However, the belief that ocean resources were endless led to the development of more efficient fishing methods, eventually resulting in overfishing and the collapse of traditional fisheries.

Show students the maps of ocean currents, upwelling, fishing grounds, and EEZs on slides 16 to 19. A gallery of the maps is linked to this lesson if students can work on their own devices. Ask students to analyse the maps and answer the questions on slide 20, either as a plenary discussion or in their books.

Reveal the impact of certain fishing techniques using the embedded videos on slides 22 to 24.

The video on slide 22 shows a recovered seabed off the coast of the Isle of Arran. Students will be able to see the edible crabs, the arms/legs of brittle stars to the left, as well as the clear sacks of sea squirts to the right, and tangles of pink bryozoans, a type of colonial animal.

The video on slide 23 is an animation that shows the impact of fishing techniques such as bottom trawling and dredging.

The video on slide 24 then shows what the seabed looks like after bottom trawling. As a note for comparison, this trawled seabed video is taken from the same area around the Isle of Arran. The difference between the two videos shows how a community Marine Protected Area (MPA) has banned fishing and allowed the seabed to recover.

Use the questions on slide 25 as prompts for discussion or written notes.

4. Case Study Enquiry (25 minutes)

Human activities such as overfishing, mineral extraction, and fossil fuel exploration have led to significant impacts on the continental shelf and associated waters. Marine science and oceanography can help understand these impacts and inform sustainable resource management practices.

Introduce the case study enquiry activity, focusing on human exploitation and impacts on the continental shelf. Provide students with a list of potential case studies using slides 27 to 29, such as overfishing in the North Atlantic, mineral overexploitation in Hallsands, Devon, and the Piper Alpha disaster. Divide students into small groups and assign each group a case study. Students research their case study, examining human activities, impacts, and potential solutions, with a brief on slide 30.

This enquiry activity could be extended into home learning.

5. Reflection and wrap-up (5 minutes)

Discuss the importance of balancing economic activities with environmental conservation in the continental shelf region. Encourage students to consider the role of scientific research, such as the Convex Seascape Survey, using slide 31, in informing sustainable management practices

Home learning

Either complete the group enquiry activity or visit the Convex Seascape Survey website and complete the reflection pyramid on Student Sheet Convex Seascape Survey.