Skip to main content

Coral reefs

Hello!

We would love to introduce you to the topic of coral reefs and especially coral reef bleaching, as it is a greatly ignored but certainly significant topic. Have fun!

5 coral reef facts

1. The Great Barrier Reef is the largest living structure on the planet and is 2300 km long!
2. Less than 0.1% of the world's ocean surface is covered in coral reefs.
3. At least 25% of all marine animals live there.
4. Coral reefs are often known as the rainforests of the ocean.
5. In 1 square kilometre of coral reef, up to 35 tons of fish can be 'produced'.

The 5 biggest coral reefs in the world

1. Great Barrier Reef (near Australia)
2. Red Sea Coral Reef (near Egypt, Israel and Djibouti)
3. New Caledonia Reef (Pacific Ocean near New Caledonia)
4. The Mesoamerican Barrier Reef (near Mexico, Belize, Guatemala and Honduras)
5. Florida Reef (Atlantic Ocean/Gulf of Mexico near Florida)

What is coral?

Coral is actually made up of small animals called polyps, who are related to jellyfish and sea anemones. Multiple polyps join together to ensure that at least some of them survive. The coral works together with algae called Zooxanthellae. The algae photosynthesise and give some of its oxygen and sugar to the coral and the coral gives the algae carbon dioxide back in return. This is called a symbiotic relationship. The coral receives up to 90% of its food from the algae. The algae also give the coral its colour. 

Coral reef bleaching

Coral reef bleaching is a term that all of us have probably heard multiple times in the last year. In 2016 and 2017 there were two mass bleaching events back to back. And afterwards, the coral was white. But why?
Coral reef bleaching is a problem that all coral reefs face. When faced with conditions that are different from normal (for instance, warmer water temperatures), the coral expels the algae. This may sound like a silly thing to do, but it is self-defence. The coral hopes that the algae will drift to an area with better conditions. If it does not, it would die. The coral's only hope is that the conditions will go back to normal and the algae will return. In the meantime, the coral returns to its original colour, white. It does not die but will slowly starve until the algae returns. If the algae do not return fast enough, then the coral dies of starvation.
10% of all coral reefs have already died due to human-caused bleaching and another 60% are severely threatened. The main causes of bleaching are changes in the water conditions, mainly caused by climate change

Your Green World Blog TeamšŸ’š


Sources:

Images:
Coral reef: This image, owned by Greg Goebel (on flickr.com), is licensed under CC BY-SA 2.0.
Bleached coral reef: This image, owned by ARC Centre of Excellence for Coral Reef Studies (on flickr.com), is licensed under CC BY-ND 2.0.

Comments

Popular posts from this blog

April Top Tips: ten tips for environmentally friendly travel

Hi Everyone! We haven't been very present on the blog again recently but we are back today with ten top tips for environmentally friendly travel. Most forms of travel over long distances (unless you are willing to put in a lot of physical effort) use fossil fuels and are generally not good for our planet. So today we will be giving you a few tips which although won't mean that your travel is 100% planet friendly, will be a good start to doing as much as you can.  Your Green World Blog TeamšŸ’š 1. Use trains and boats rather than planes where possible Planes are awful for the environment. They are, however, extremely practical and so easy to use, cheap...It's hard to avoid them! They are so quick too so you don't have to spend as much time travelling. However, they are really bad for the environment. For example, you could fly once to Edinburgh from Heathrow for the same carbon dioxide levels as driving to Edinburgh 336 times! 2. Fly...

El NiƱo & La NiƱa - what are they and what effects do they have?

Hello everyone, You've probably heard of El NiƱo and La NiƱa before. Especially El NiƱo has been discussed a lot recently in the media. El NiƱo and La NiƱa are part of a climate pattern found in the Pacific Ocean that occurs roughly every two to seven years. However there is no real regularity or predictability further into the future. They affect global weather patterns and economies. So first of all, let's cover what is actually happening here. In normal circumstances trade winds blow across the Pacific from South America to Asia. This pushes warm water from South America to Asia meaning that the ocean is a lot cooler off the west coast of the Americas compared to the east coast of Asia. The cold water off the coast of the Americas comes from the ocean's depths and is filled with nutrients. During El NiƱo those driving trade winds become weaker or even stop entirely. Scientists haven't work...

Maldives - the direct impacts of climate change

Welcome back, Today we’re looking at the direct impacts of the climate crisis . The main reason why people don’t believe in climate change is that they can’t see it with their own eyes. So, we’re going to have a look at the Maldives where the effects of climate change become more obvious with every passing year. Maldives The full name of the Maldives is The Republic of the Maldives. It is an independent country made up of about 1 200 islands in the North Indian Ocean. The northernmost island is situated 370 miles away from the mainland (India). The islands are actually the tips of an ancient volcanic mountain range that is now almost completely submerged. In fact, the highest point is 1.8m-2.4m above sea level with the average elevation being 1m above sea level. The islands have a large tourism industry, due to the stunning nature found on and around the islands. 500 000 - 1 500 000 tourists visit the islands each year. This is mainly 'nature to...

Announcement: Factfile

This image is owned by a blog editor.

Marine heatwaves - an ever growing threat?

Hi everyone, So today we're talking about marine heatwaves. We all know about normal heatwaves, they come almost every summer and are either a blessing or a curse depending on where you live. But today we're talking about marine heatwaves. They are increasing rapidly and have become a commonly mentioned topic. There are multiple definitions of marine heatwaves. Generally, they are considered a period of time with unusually high temperatures. Exactly how high and for how long changes depending on which definition you choose. The most common one definition is when the temperature is over the 90th percentile of the area's average seasonal temperature for at least 5 days in a row. For anyone who doesn't know what a percentile is, if you take a test and are at the 90th percentile then it means you are better than 90% of the people who took that test. So in our context, the temperature has to be higher than 90% of the seasonal temperatu...

Marjory Stoneman Douglas

Hi everyone, Today we wanted to talk about Marjory Stoneman Douglas, a writer, and conservationist who lived from 1890 to 1998. To find out more about other inspirational environmentalists, we already have posted about  Dara McAnulty ,  Wangari Maathai ,  Sir David Attenborough ,  Maria Sibylla Merian ,  Rachel Carson , and  Jane Goodall . As stated above, Marjory was born in 1890, in Minneapolis, USA. In her childhood, she was a passionate reader, which lead her to study English at University and to become a journalist for a newspaper her father ran. Through this job, Marjory was able to spread awareness about issues she cared about: politics, civil rights, the suffrage movement, and of course, environment conservation. In the early 1940s, Marjory became interested in the Everglades in South Florida. At this time, very little was known about them, so she spent five years researching their history and ecology. The book she w...

January Top Tips // 5 ways you can individually tackle climate change

Hi Everyone! This is the first of our new monthly posts for 2022! We will be sharing top tips every month, near the beginning, for things you can do during that month for the better. It's almost like a whole year of new year's resolutions (though let's hope they are achieved)! In these posts, we aren't just going to talk about climate change , of course, there will also be posts about animals , plants, habitats, plastic pollution and so much more! They will not be huge tips though, they won't demand too much of you (usually!). We need rebellions and people in the public eye spreading the word of course but we also need people like you, who can just do their bit. So, welcome to our top tips posts! We all know that we need to come together to fight the climate crisis, but we don't seem to be doing that right now. So here are our top tips for ways you can individually tackle climate change, even if this means simply spreading ...

Hummingbirds

Hello, Today, we're talking about an amazing group of birds that are known for their colours and the speed they beat their wings. That's right: hummingbirds! General Hummingbirds live in North and South America. They are some of the smallest and most colourful birds in the world. There are about 330 different kinds. Their name comes from the humming sound that their wings make. They eat nectar and insects using their long bills. Some species migrate during the winter. Flight The wings of a hummingbird beat so fast that the hummingbird can hover in one place and can fly forwards, backwards or sideways. Small hummingbirds beat their wings about 70-80 times per second. During courtship displays or when chasing rivals, their wings can beat up to 200 times per second. Feeding Hummingbirds eat the nectar from the insides of flowers. They hover in front of a flower and put their long and slender bills inside to suck up the nectar. This prov...

The limits of the Earth - the planetary boundary model

Hi everyone, So today we're talking about a model that was introduced in 2009 and has offered a new perspective to thinking about environmental issues. The planetary boundary model has 9 boundaries, each has a safe zone. Once the safe zone is exceeded, the stable conditions on our planet are considered at risk, and there can be severe and possibly irreversible changes. The nine boundaries are considered separate however, they greatly affect each other. Novel Entities describes the introduction and accumulation of man-made novel chemical compounds. These include pesticides, nuclear waste and microplastics. Stratospheric Ozone Depletion refers to the depletion of the ozone layer which was a major problem in the 90s. Atmospheric Aerosol Loading is air particle pollution.  Ocean Acidification is self-explanatory. The boundary Biochemical Flows is composed of two separate boundaries; nitrogen and phosphorus. Both of the ele...

2022 in a nutshell - stats, opinions, updates and goals

Happy New Year! We hope you are all enjoying the last day of 2022 (or whatever day you are reading this on). Today we are going to be looking back on 2022 and setting goals for 2023.  2022 in stats 48 posts 3191 views most viewed post: The Amazon Rainforest part 4 best posting month: October worst posting month: March 166% increase in views compared to last year How was it for us? Elsie: I really enjoyed this year from about May. After some behind-the-scenes changes, we managed to get so many more posts out and writing them felt a lot less stressful. I also really enjoyed the experience of having a guest blogger (click here ). My favourite posts to write were the Pride Month post and the ' how trees communicate ' post. They both required quite a bit of background research, which was fun and interesting. Freya: Although I haven't written on here as much as I was hoping this year, I have loved still being a part of this blog ...