Living as part of a blue planet

Whilst it may seem that here in Cambridge we could not be further away from the oceans, this is simply not true. As part of a blue planet, we rely on the marine environment for almost all aspects of our daily lives, from controlling climate and the oxygen we breathe, to supporting activities we enjoy and the food we eat. We are intrinsically connected to the threats that the oceans face, but importantly also to the solutions for saving them! It is time to start acting more proactively in our daily lives if we want to ensure that the damage we humans have caused can be reversed and that we can enjoy healthy oceans once more!

Coral reefs form the most biodiverse ecosystems in the world and as the most critically and irreversibly endangered, they must take centre stage when we consider marine conservation. As an example, one single reef from the Coral Triangle in the Indo-Pacific can be home to as many as over 1500 species of fish and 600 species of corals – all relying on each other in a close symbiosis! Unfortunately, due to multiple human effects, reefs around the world are being degraded and lost forever. One of the major impacts comes from the warming of ocean waters around the tropics, which causes a process known as coral bleaching. A permanent increase of as little as 1ºC above the normal average sea temperature can lead to the death of a coral reef and as shown by the photo on the right the noticeable difference is truly heartbreaking! We will return to explore the effects of coral bleaching in sections further down, but it’s important to remember that its impact is worsened by other human activities, so the actions we take need to address them collectively!

Most of the problems the oceans face, such as coral bleaching and pollution, are caused by the small actions that we might not think make a difference. Major threats stem from our daily use of nonrecyclable plastics, consumption of fish from fisheries that damage the environment, and the energy we use around the house (like leaving lights or other electronic appliances on when not in use) – all of these are very easy to reduce!

There are many things you can do daily to have a positive impact. From recycling plastic to raising awareness for conservation campaigns, all of these solutions help us to protect the oceans and the livelihoods they sustain for the future!

To better understand the actions you can take and how they help, try to match each of the problems shown on the poster (on the right) with a relevant solution! The answers are shown as inverted at the bottom.

Among the numerous threats to ocean biodiversity, coral bleaching is projected to cause the biggest disturbance to the reef communities supporting fish stocks and to the hundreds of millions of people that rely on them. The bleaching process all comes down to the symbiotic relationship between the polyps forming the coral structures and tiny zooxanthellae algae that live inside their cells and provide the polyps with nutrients in exchange for a safe home. When the algae are stressed by changes in ocean temperature, intense sunlight or pollution, they actively leave the coral and break that relationship, so the polyps begin to starve and may die. As the algae have photosynthetic pigments, the colour of the corals disappears together with them and that is how we see bleaching occur. Importantly, if conditions improve the algae can be up-taken by the coral again and some species are more resilient to environmental changes than others, so there is some hope for restoration projects. The colour reference chart, which you can see on the bottom of our coral photos and shown here as used by researchers at the University of Queensland, was originally developed by Siebeck et al. in 2006 and it has been very important for allowing a cheap and reliable method to standardise the surveillance of coral reefs around the world by comparing their colours in each stage of the bleaching process to the relevant hue of the chart. The bleaching shown in the photos has been scaled to represent what a 1ºC increase in temperature would cause for the corals.

Multiple citizen science projects are currently using this methodology, offering an opportunity for the public to get involved.

To illustrate how you can use the Coral Health Chart described above, you can try to score the following corals yourself and arrange the five images by the degree of bleaching that you observe from the healthiest to the most severely affected. The Coral Watch website has a lot of useful information if you want to learn more about how to use the chart and how you can actively get involved yourself in monitoring coral reefs in the UK or abroad. The answer for their order is given on the last image.

How our trash can travel the seas

As well as the effects of climate change and ocean acidification, the biggest problem that we should aim to combat as individuals is marine pollution. The amount of trash that is shipped around the world and eventually dumped into the oceans can be easily reduced if we all recycle more of our products, especially our clothes and plastic items that can be reused, repurposed, or replaced with organic biodegradable materials. In our quiz, you can see some surprising (and common) items that have been found on a coral reef off the coast of Singapore.

Choosing sustainable fish to eat

The fishing industry has a huge effect on marine ecosystems around the world, with millions of people relying on fishing for their livelihood and as an important source of protein. It would not be feasible to completely stop extracting fish, but what we can do is support the fisheries that are the most sustainable. If for whatever reason you cannot stop eating fish altogether, the Good Fish guide is a brilliant resource for getting information on what fish is good or bad to eat, based on which fishery it comes from and what their impact on the environment is. Here is a fun quiz for you to practise using the guide!

This short quiz asks about certain types of fish, and what the sustainability impact of eating each of them is, ranked from “Good” to “Terrible”. Whilst eating no fish or seafood is the best way to avoid damaging marine ecosystems, it is possible to enjoy fish sustainability too. You can download the MCS Good Fish guide for free here to help you work out how each fish is ranked, or make your own predictions and submit your answers – the quiz will generate a summary at the end discussing pros and cons of each fish, based on the Good Fish Guide. Make sure to click “View Score” at the end to see how you did!

Cambridge University Marine Conservation Society

All of the material was created collaboratively by the committee of the Cambridge University Marine Conservation Society: Nikita Bedov, Rosa Prosser, Kathryn Skazick, Shermen Ang and Tom Wyllie. With special thanks to Dr Toh Tai Chong and Manjeeti Paton for their assistance. All photos are copyright-free and were edited by Nikita Bedov for illustrative purposes on this page.

We hope that these resources can help to promote and encourage the need for marine conservation and the daily actions that we can all take individually for this cause – only together can we save the world!

If you have any questions or are interested to find out more, please do not hesitate to email us at or message through our Facebook page!

Related Posts

Stories to Inspire

Q&A – How can we choose sustainability?

Join us for an expert panel discussion about how we can choose sustainability.

Stories to Inspire

The making of an island

Discover how Europe's biggest conservation NGO teamed up with Crossrail to create one of the largest wetlands in western Europe while simultaneously protecting vulnerable coastal communities from flooding.

Make a Difference

Keep fish on your plate and in the sea, forever

2021 is a chance to make better choices for us, and our planet. Where better to start than with the food we eat every day. Check out these top tips from MSC to help you make better seafood choices every day.