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 temperatures measured in that area (normally over a 30 year period) for at least 5 days.

So what are the impacts of such an increase in temperature? Surprise surprise: marine heatwaves aren't exactly good for the environment. It is worth mentioning here, that marine heatwaves are natural occurances in the ocean temperature and have always been around. But the frequency and intensity of them is not natural. Both of these parameters have been rising rapidly in the last 100 years. Marine heatwaves can cause waters to reach temperature of 30°C, which is about the temperature of a warm bath. El Niño, a weather cycle that repeats about every 7 years, is shown to cause stronger heatwaves.

In the late 1990s, a marine heatwave intensified by El Niño lead to a reproductive failure and mass mortality in Galápagos sea lions and king penguins. Then, in 2011, the western coast of Australia was hit by a marine heatwave that caused the mass dieback of kelp forests and impacted ecosystems hundreds of kilometers further along the coast. An interesting phenomen was seen here, when several fish species changed their habitat and spread further towards the poles. This has been seen a couple time since in multiple species, sometimes the fish return once the waters have cooled, sometimes they stay in their new home and sometimes they die, either from new predators or a lack of food.
In 2014-2016, the northeastern Pacific saw mass mortality in seabirds as they failed to adapt to soaring temperatures. In 2017, there are reports of mass mortality affecting 40 coral reef fish species correlated with an increased risk of bacterial infection and harmful algal blooms, which produce toxins. And finally, in August 2020, a marine heatwave in the East China Sea caused a major typhoon in that area. The East China Sea rarely experiences typhoons and normally those that come in from the Pacific tend to die down, but this time the high surface temperatures caused a typhoon of Category 3.
There are some postives, mussels have been found to be able to change their heart rate so as to better deal with higher temperatures. This is just one example of how amazing and resilient nature can be.

So marine heatwaves are clearly a massive problem. As you can imagine, typhoons and collapsing fish populations are also a bit of a disaster for us. These marine heatwaves will only continue to become more frequent and more devastating as climate change warms up our oceans. We couldn't cover all of the aspects in this post so let us know what we missed in the comments. We hope this was a good introduction in this complex topic. Have a nice weekend!

Your Green World Blog Team💚

Sources:
https://www.nature.com/articles/s41612-023-00449-5
https://www.annualreviews.org/doi/10.1146/annurev-marine-032122-121437
https://en.wikipedia.org/wiki/Marine_heatwave
https://www.sciencedaily.com/releases/2023/09/230921105743.htm

Image:

Title image: This image is owned by a blog editor.
"Galapagos sea lion", owned by Darek Keats (on flickr.com), is licensed under CC BY 2.0.
"Baltic blooms", owned by European Space Agency (on flickr.com), is licensed under CC BY-SA 2.0.

Comments

16.08.2020 Animal of the week: Elephant

Hello. On the 12th of August it was International Elephant Day, so we decided that this week's post should be about elephants. Elephants are the largest living land mammals. There are three types of elephant; the African bush elephant; the African forest elephant and the Asian elephant. African elephants have larger ears, whereas Asian elephants have smaller ears. Elephants use their trunks to breath, bring food and drink to their mouths and to grasp objects. Elephants' legs are like pillars. They carry the Elephant's massive weight. African bush elephants weigh 6000kg, Asian elephants weigh 4000kg and African forest elephants weigh 2700kg. Basically, they are very heavy.Elephants eat grasses, small plants, bushes, fruit, twigs, tree bark, and roots. Elephants can live up to 70 years old in the wild. They communicate by sight, touch and smell. Sadly, these wonderful mammals are in danger. African elephants are listed as vulne...

Discussion || Should Everyone Switch To Electric Cars?

Hi Everyone! Thank you so much for joining me today, as I hop on the blog to discuss whether everyone switching to electric cars would really help the environment. In other words, should everyone switch to electric cars? This is the first part of a two-part series, discussing electric cars, so stay tuned for part two!! I would like to start this post by stating that I am by no means an expert. This is knowledge I have from my own experience, and from research I have done. If anything is incorrect please take it as it is and accept that this is a discussion and I am taking on board all opinions from reliable sources on this complex topic. Electric cars are a huge topic when it comes to sustainability and "saving our planet". There is no debating the fact that electric cars are better for the environment than diesel or petrol once they are on the road. But the production of them is often very polluting, with one study show...

Greta Thunberg's Speech at the UN Climate Action Summit 2019

Hi Everyone! I thought I would share the transcript of Greta Thunberg's inspiring speech from the UN Climate Action Summit. The phrase we remember is 'How dare you!'. But what did she really want us to take away from it? She wanted us to act, so watch the video using the link below and take action because the world isn't just going to heal itself. Greta Thunberg's speech at the UN Climate Action Summit video "My message is that we'll be watching you. This is all wrong. I shouldn't be up here. I should be back in school on the other side of the ocean. Yet you all come to us young people for hope. How dare you! You have stolen my dreams and my childhood with your empty words. And yet I'm one of the lucky ones. People are suffering. People are dying. Entire ecosystems are collapsing. We are in the beginning of a mass extinction, and all you can talk about is money and fairy tales of eternal economic g...

Linking climate change and inequality - 'The Great Carbon Divide'

Hey everyone, Have you heard of 'The great carbon divide‘? It is often referred to as the 'carbon footprint gap' or the 'emissions imbalance‘, and produces frightening numbers. The great carbon divide describes the huge gap between the amount of carbon dioxide the rich versus the poor emit, and these numbers shocked even us. What does this mean? There have been many different studies, and all of them show terrifying results. One study from the Guardian and Oxfam, reports that the richest 1% of the world's population emit more carbon than the poorest 66%. The richest 1% consist of 77 million people, which may seem like a lot at first, but the poorest 66% refers to over 5 billion people! Africa, which is home to 17% of the world's population, only causes 4% of the world's emissions. This top 1% emitted 16% of global CO2 emissions in 2019, that's 5.9 billion tonnes of CO2. Modelling suggests that it would take someone who isn't in the top 1% about 150...

Ecosia

We all need to do something to save our planet: it is no use just leaving it to Greta Thunberg! She is very inspirational, yes, but she can only do so much. She isn't superhuman! The climate crisis is up to us; up to you. We all have to get stuck in. Research, learn, discover and most importantly: never give up! The world's animals need us. The world's trees need us and a simple way to do this is to switch to Ecosia. Ecosia is a search engine but it plants trees while you search the web. Okay, it doesn't have as many websites as google so you may want to have google as a backup but it plants trees: this is your opportunity to make a simple change. Just google Ecosia and search to plant trees. Make a difference. Image: This image is owned by Binyamin Mellish on pexels.com .

An exciting initiative from Co-op and Sainsbury's...

Hi Everyone! Today I want to tell you about something I think is very exciting. If you want to recycle more plastic then this could be your chance! Co-op and Sainsbury's have both launched a new soft plastics recycling scheme where you bring your 'soft plastics' (things like crisp packets, chocolate wrappers and fruit and veg bags) into a designated area. For 'hard plastics' such as yoghurt pots, juice cartons and fruit and veg punnets, you can use either your local kerbside collection but not every area collects plastics in this way, including mine so we collect ours and bring it to the tip ourselves. To check if it's a soft plastic you can use the scrunch test- scrunch up the object and if it pings back then it is probably plastic. Then you need to clean it and bring it into one of the stores. Co-op even accepts plastics from other retailers! Co-op uses the plastic to make bin bags for use in the store which I think is a g...

Eco system Galápagos: Part 1 Geography

Hello and welcome to the first post about the Galapagos Islands. Currents and Winds The volcanic islands of Galápagos started to form 4 million years ago. Where they lie, is unique. They are situated directly on the equator, on the Nazca tectonic plate. The Galapagos Islands are on the crossroads of three currents. The cold South Equatorial Current flows westward towards Galapagos. The warm Panama Current runs in from the north. And finally, the deep sea Cromwell Current runs from the west. The Galapagos Islands are also where the Northeast Trade Wind meets the Southeast Trade Wind. Galapagos Hotspot 21 Volcanoes make up the Galápagos Islands with 13 still active. The reason for this volcanic activity is a giant hotspot under the island. A hotspot is a gigantic column of super heated molten lava, rising up towards the surface. It is immense; at least sixty miles (97 kilometers) across and 1800 miles (2897 kilometers) deep. It connects the islands to ...

How much do you know about air pollution? | quiz

Hi Everyone! Welcome back to another quick quiz! Today we wanted to share some questions about air pollution. This is a very complex issue with many statistics, so these were all taken from reliable sources such as Friends Of The Earth ( friendsoftheearth.uk ) and the World Health Organisation ( who.int ). We hope this is educational and enjoyable! Let us know your score in the comments, or which answer surprised you the most! 1. Around how many early deaths are caused by air pollution each year in the UK? a) 3, 000 b) 30 000 c) 300 000 2. Which of these can microscopic pollutants affect? a) lungs and heart b) lungs and brain c) lungs, heart and brain 3. How long did it take for a road in London to breach the air pollution limits for the year in 2017? a) 5 days b) 5 weeks c) 5 months 4. True or False? You are exposed to 8 times more pollution as a cyclist compared to being inside a car. 5. How...

The life of ... an emperor penguin

Hello, Today, we're looking at the fascinating lives of emperor penguins. These incredible creatures have adapted to survive in the extreme conditions of Antarctica, and in this post, we'll explore their incredible lives. In late May to early June just before the Antarctic winter sets in, female emperor penguins lay a single egg. They then leave the colony and go on a two month hunt. The male rests the egg on his feet and covers it with warm, feathered skin called the brood pouch. He will eat nothing for these two months. The chick hatches in August and the female returned to take over. She has spent two months feeding and now regurgitates some food for the newly-hatched chick. The male leaves to feed himself as he has been living off his fat reserves for the past two months. The female keeps the chick in her brood pouch until the sea ice close to the breeding site breaks up as the temperatures warm. The chick is now strong eno...

Green World

Search This Blog