What is IGCSE Marine Science? Overview for Students

IGCSE Marine Science is one of the most distinctive and rewarding science subjects you can choose. It opens a window into the ocean - how it works, why it matters and how humans depend on it. This guide gives you a clear, confident overview of what the course includes and helps you decide whether it’s the right fit for your interests and future goals.

Key Takeaways

• IGCSE Marine Science explores ocean biology, chemistry and physical processes, helping students understand how marine ecosystems function and why they matter.

• The course covers six core topics including sea water, marine organisms, ecology, and human impacts on the ocean.

• Assessment consists of two written exam papers testing knowledge, data handling and practical investigation skills.

• Students develop strong analytical, scientific and environmental skills useful for further study in biology, geography or environmental science.

• Marine Science supports future pathways in marine biology, conservation, oceanography and sustainability-focused careers.

What is IGCSE Marine Science?

IGCSE Marine Science (opens in a new tab) is a Cambridge science qualification focused entirely on the ocean. Its aim is simple and powerful: to help students understand the biology, chemistry and physical processes that shape marine environments, and the ways humans interact with them. 

The course explores everything from microscopic plankton to global ocean currents. It shows how life survives underwater, how ecosystems function, and how climate change, pollution and overfishing affect the seas. 

This subject is ideal for anyone with a curiosity about marine life or global environmental issues.

What Topics Are Covered in IGCSE Marine Science?

The syllabus is broad and engaging, blending biology, ecology, chemistry and environmental science. Here’s a breakdown of the six topic areas:.

The Earth and its oceans

• The Earth’s layered structure (core, mantle, crust).

• Tectonic plates - earthquakes, volcanoes and tsunamis.

• Continental shelves, trenches and ridges.

• Currents moving water around the world.

• Tides caused by the Moon and Sun.

Sea water

• Water moving through the water cycle (evaporation, condensation, precipitation).

• pH and salinity depending on location.

• Dissolved gases such as oxygen and carbon dioxide (and their origins).

• Temperature and density of water, and convection currents.

Marine organisms

• Cells and organisms - living things grouped into domains and kingdoms.

• The reasons behind the movement of marine organisms - finding food, breeding or seeking safer habitats.

• Vertical migration (up and down water layers) and horizontal migration (across the oceans e.g. whales and turtles).

Nutrients and energy

• Nutrients for growth, repair and energy: proteins, carbohydrates, lipids, vitamins and minerals.

• How nutrients are recycled within ecosystems through the action of decomposers.

• Photosynthesis - marine producers include plants, algae and some bacteria.

• The function of upwellings in bringing nutrients to the surface.

• Energy ecosystems - how energy from the Sun is transferred through food chains and webs.

Marine ecology

• Population fluctuations and the impact of food, disease, predators and competition.

• Types of marine ecosystems include coral reefs, mangroves, rocky shores and the open ocean.

• Coastal ecosystems - productivity and the impact of human activity.

• Sampling species using quadrats and transects.

Human influences on the marine environment

• Humans’ dependence on marine ecosystems - food, tourism, materials and coastal protection.

• The impact of overfishing, pollution, development and tourism.

• Sustainably of fishing (quotas, protected areas, seasons).

• Aquaculture (fish farming).

• Oil extraction and spills.

• Plastics and microplastics.

• Excess fertilisers - algal blooms and oxygen loss.

• Climate change - sea levels, temperatures and marine habitats.

How is IGCSE Marine Science Assessed?

Cambridge IGCSE Marine Science 0697 is externally assessed. There are two exam papers that students sit at the end of the course.

Paper 1 – Theory and Data Handling

• Written paper, 1 hour 45 minutes, 80 marks

• This paper contains compulsory short-answer and structured questions.

• Paper 1 tests assessment objectives AO1 (Knowledge with understanding) and AO2 (Handling information and problem-solving).

Paper 2 – Theory and Practical Skills

• Written paper, 1 hour 45 minutes, 80 marks

• This paper contains compulsory short-answer and structured questions.

• Paper 1 tests assessment objectives AO1, AO2 and AO3.

Assessment objective AO3 (Experimental skills and investigations) assesses candidates’ understanding of practical skills in both familiar and unfamiliar contexts.

It is tested in Paper 2 and accounts for 40% of the marks for Paper 2 and 20% of the marks overall. 

While studying the qualification, candidates are expected to be able to do the following (these are skills acquired when completing practical activities detailed in the syllabus):

• Demonstrate knowledge of experimental techniques, apparatus and materials and how to use them safely.

• Plan experiments and investigations.

• Make and record observations, measurements and estimates.

• Interpret and evaluate experimental observations and data.

• Evaluate methods and suggest possible improvements.

Skills You’ll Develop in IGCSE Marine Science

Marine Science builds a strong foundation in scientific thinking - all through the lens of the ocean. Skills include:

• Critical thinking: interpreting new information quickly and accurately.

• Observation and analysis: reading data, graphs and experimental results.

• Environmental awareness: understanding global ocean issues and conservation.

• Scientific literacy: writing clear, precise explanations using scientific terminology.

• Problem-solving: predicting outcomes and analysing human impacts.

• Fieldwork mindset: planning investigations and thinking like a scientist.

These skills transfer into any science subject, and many non-science subjects, and are especially useful for students considering environmental or biological careers.

Why Choose Marine Science?

Marine Science stands out from the usual IGCSE subjects - the world’s oceans cover about 71% of Earth’s surface (opens in a new tab), yet most people know little about them.

IGCSE Marine Science is:

• Unique and fascinating: No other subjects take you deep into topics like coral reefs, ocean currents, climate change and marine animals. It’s science with a sense of adventure.

• It’s globally relevant: Understanding marine science helps you engage with major issues such as sustainability, conservation and climate change.

• It appeals to curious, environmentally minded students. If you care about the planet, wildlife, ecosystems and scientific discovery, this subject gives you the opportunity to explore those interests.

Tips for Success in IGCSE Marine Science

Make Use of Visual Aids

Marine systems are often easier to understand when you can see them visually. Fortunately, there are a wealth of relevant resources that should be easy to access. Seek out:

• Diagrams and labelled sketches.

• Infographics.

• Videos and documentaries.

• Model animations of, for example, currents, tides and reef structures.

Practise Interpreting Data

Both papers require you to be able to interpret and evaluate experimental observations and data. Practising the following is essential:

• Reading and describing charts, tables and other methods of displaying data.

• Spotting trends and anomalies in data.

Students should review past papers and mark schemes to familiarise themselves with the common types of questions.

Connect Learning to the Real World

Marine Science is science live - you can learn from text books, but real-world case studies should prove far more compelling. The following will help bring the subject to life:

• Watching marine documentaries.

• Following ocean news and conservation projects.

• Researching real case studies (e.g. coral bleaching, overfishing).

• Exploring virtual field trips and oceanographic maps.

• Finally, if you live near the sea, engage with relevant volunteering activities.

Frequently Asked Questions

Is IGCSE Marine Science hard?

It’s no harder than other science subjects. The syllabus is extensive and students will need to have (or acquire) great data-handling skills and the ability to apply theory to a range of different scenarios. 

That being said, students who have a passion for marine science tend to thrive.

How is Marine Science different from Biology or Geography?

Marine Science combines parts of both subjects, but focuses entirely on the ocean. Like Biology, it explores ecosystems and organisms. 

Like Geography, it studies tides, currents and human impact. There is definite overlap, so all three subjects are complementary.

What careers can IGCSE Marine Science lead to?

Marine science helps prepare you for a number of pathways, including: marine biology, environmental science, oceanography, conservation and sustainability, fisheries management, ecotourism and climate research. 

It’s a strong starting point for anyone interested in ocean or environmental fields.

Final Thoughts

IGCSE Marine Science is a fascinating subject that blends scientific discovery with real-world impact. It helps you understand the ocean - the system that shapes weather, supports ecosystems and sustains life on earth. If you’re curious about marine life, passionate about the environment, or excited by science that connects directly to global challenges, this course could be ideal for you.

References

• Cambridge IGCSE Marine Science (0697): (opens in a new tab)https://www.cambridgeinternational.org/programmes-and-qualifications/cambridge-igcse-marine-science-0697/ (opens in a new tab) 

• National Geographic (opens in a new tab) https://education.nationalgeographic.org/resource/ocean/ (opens in a new tab)