15 Surprising Facts About Marine Biology

marine biology

Marine biology is the scientific study of all aspects of the ocean. Marine biologists explore and look at how marine life interacts with its environment. They aim to provide information that can be used to protect the world’s oceans, as well as discover new species and find out more about our own planet.

It’s no secret that our oceans and seas are filled with some pretty weird critters, but did you know just how much we have to learn about these fascinating animals?

Most marine creatures are still a mystery to us

A fish swimming under water

Despite being one of the most heavily researched branches of biology, we still know very little about marine life. In fact, only 5% of the ocean has been explored! This means that there are plenty of creatures out there waiting to be discovered.

Some marine animals can survive in extreme conditions

A piece of food

There are a few creatures that can thrive in some pretty harsh environments. For example, the icefish lives in cold water and has no red blood cells, while the tardigrade (or water bear) can survive in temperatures as low as -273 degrees Celsius.

Marine animals come in all shapes and sizes

From sponges to starfish, marine life ranges from a few millimeters long to the massive blue whale.

Many species of fish can change their sex during mating seasons

It’s not uncommon for a female fish to become a male then back into a female again, but this is different for every species. For example, clownfish will always be born as males and live in colonies with one dominant breeding female. When she dies or is unable to reproduce, one of the males changes sexes and takes her place until he too cannot breed anymore at which point another male becomes female. Some types of wrasses only have males in their group all year round while others have both males and females at certain times of the year when there is a need for more breeding.

Some marine animals can glow in the dark

There are a few creatures that emit their own light, including some fish, jellyfish, and bacteria. This can be used to attract prey, ward off predators, or just to look pretty!

Marine animals come from all over the world

Marine life can be found in every ocean on Earth and even in some of the planet’s lakes and rivers. No matter where you are in the world, there’s always something swimming around in the water!

Marine biology is essential for our survival

The ocean plays a vital role in regulating our climate and supplying us with food and oxygen. In fact, it’s estimated that more than half of the oxygen we breathe comes from marine plants.

The world’s largest animal is a marine invertebrate

In 2006, Australian scientists discovered fossils believed to be from an extinct sea creature called the blue whale ancestor – a marine invertebrate that was four times as long as a blue whale and weighed in at around 30 elephants! Other notably large creatures include the giant clam (measured across its shell) which can weigh over 400 kg (900 lbs) and reach lengths of up to 1.2 meters (3 feet 11 inches).

Marine biology has its own language

Marine biologists use their own set of jargon when discussing or writing about their work. For example, a coral head is a small coral colony that has grown large, while a trochophore is a type of free-swimming planktonic larva.

Marine animals are important for tourism

Many coastal towns and villages rely on marine life for their tourism industry. Snorkeling, diving, whale watching, and fishing are all popular activities that bring in money for local businesses and communities.

Some marine animals can be harmful to humans

Although the majority of marine life is harmless, there are a few creatures that can cause harm if they’re handled incorrectly or if someone eats them. For example, some jellyfish can cause stings while cone shells can release venom that can be fatal.

Marine animals are being threatened by climate change

Global warming is having a devastating effect on marine life, with many species struggling to survive in changing conditions. Coral bleaching is one of the most visible signs of this, where the coral turns white as it dies due to high water temperatures. This can cause entire reefs to die, which has a serious impact on the marine ecosystem.

Marine animals are also threatened by pollution

Oil spills, chemical leaks, and garbage all pose a serious threat to marine life. Over time, these pollutants can accumulate in the bodies of fish and other creatures, leading to health problems and even death.

Marine animals are being used in medical research

Many marine animals are used in biomedical research because their bodies are similar to human bodies, making them useful for studying things like the effects of drugs, the impacts of pollutants, and how well certain treatments work. Some species have even been used as models for humans – for example, zebrafish have genes that are extremely similar to our own so they’re often studied to understand genetic defects and diseases including cancer and neurological disorders.

Marine animals can be a big business

Marine life is exploited by fisheries or aquaculture farms around the world to produce food, medicinal products, cosmetics, and other items that people use every day. In fact, some types of fish farming provide more than half of all seafood consumed on the planet.


Marine life is a fascinating and important part of our world. From the largest creatures on the planet to the tiniest plankton, every type of marine animal plays a role in the health of our oceans and the planet as a whole. It’s essential that we do what we can to protect these amazing creatures for the sake of both ourselves and future generations.

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