Overcoming Misconceptions About the Oceans
Despite the ocean covering 70% of Earth’s surface and its waves lapping at the shores of the continents we all live on, many people around the world have a poor understanding of our planet’s largest natural wonder. Some misconceptions are rather small and finding out the truth just adds another interesting, wacky fact to our brains. Yet many of our misunderstandings can be extremely harmful to our oceans as we fail to understand the true impact of our actions on marine ecosystems. So let’s delve into our seas and start sifting the fact from fiction.
Misconception 1 – Whales spray water from their blowholes. Blowholes actually act as a whale’s nose, allowing them to take in oxygen when they rise to the surface. The giant puffs they let out which signal their location for miles around are actually the result of their exhale. As whales breathe out, the warm air from their lungs meets the much cooler sea air and condenses into water vapour. Alongside this water vapour, whales also eject mucus… those whale watching trips don’t sound quite so majestic now! In fact, scientists are now using drones with petri dishes attached to them to fly over whales, catch the mucus from their blows and analyse the slime to identify viruses, DNA and environmental toxins in whales’ bodies.
Misconception 2 – Great garbage patches are floating islands of trash. When we hear of the Great Pacific Garbage Patch, we often conjure an image of a mountain of plastic bottles and bags which peter out to create a flatter shoreline of straws and Styrofoam chips. In reality, these giant patches of rubbish are composed mainly of microplastics which we struggle to see with the human eye and this explains why these patches can’t be seen from space despite their enormous size. The natural currents of the ocean create a large whirlpool type system which pulls in pieces of plastic before trapping them in the centre of the swirling water. Yet the plastic is distributed all the way through the water column, accumulating not just on the surface but all the way down to the invisible sea floor. So instead of forming an island, these areas of the sea are more like a cloudy alphabet soup, with the various letters switched for an array of tiny plastic fragments.
Misconception 3 – Great garbage patches can be cleaned up easily. With most of the plastic in these patches bobbing about under the surface of the water, clean-ups are actually very difficult and in fact, a significant amount of the plastic in our oceans is trapped within ice caps, the sea floor and even animals’ bodies, making it impossible for us to reach. Whilst new technology is allowing us to scoop up some swathes of junk from the sea surface, tiny nanoplastics are still able to escape our best efforts and continue on their way to wreak havoc under the waves.
Misconception 4 – The hottest part of the ocean is at the Tropics. Whilst the warmest sea surface temperatures indeed lie within the tropics and form gentle ripples around palm fringed coastlines, the hottest part of the ocean is actually near the sea floor. In certain areas of the world far below the waves, the Earth’s crust is very thin and red hot magma slowly travels beneath the seabed. In places where there is a crack, seawater enters the gap, gets warmed by the magma and can then explode from these cracks at 400°C! These areas are called hydrothermal vents, the underwater equivalent of a volcano and these geological features are thriving with life as living beings use chemical energy to convert the water from the vents into sugars to eat.
Misconception 5 – Plastic takes 450 years to break down. This is a common statistic which has been shared by multiple organisations, yet plastic was only invented 150 years ago and only became a popular item found in households in the 1950s. So how do we really know how long plastic will take to break down? The second issue with this statistic is that it implies that plastic will break down, yet in many cases, plastic simply breaks up. The inventor of plastics certainly did their job well as this material was designed to last forever and unfortunately, it does this far too effectively. Plastic does not biodegrade like many of our other materials, rather it photodegrades which means that the sun beats down on the plastic until it is split into individual molecules which then form miniscule nanoplastics, invisible to the naked eye. So that single use water bottle, designed to last maybe an hour, could remain on our planet ultimately, forever.
Misconception 6 – Sharks hunt humans. Sharks have been given a ruthless reputation for years as merciless killers, yet out of nearly 500 different shark species, only three have a body count of over 10. Humans simply aren’t part of a shark’s natural diet, with many preferring to snack on krill, small fish, molluscs and maybe the odd seal. Whilst shark deaths are on the rise, this is simply because humans are rediscovering the joys of spending time in the ocean, not because sharks have suddenly developed a refined palette.
Misconception 7 – The oceans are big enough to dilute pollutants safely. In previous decades, many believed that the oceans were so vast that they could easily absorb all our waste and no one would notice any difference. In fact, a common mantra was ‘the solution to pollution is dilution’. Whilst this may have been true when our population was dramatically smaller and the only waste we produced was sewage, this phrase has been held onto for far too long as our giant quantities of rubbish now consists of chemicals, oil and plastic. These can lead to algal blooms and disease within marine ecosystems but thankfully, it seems some businesses are now realising that waste is a by-product of inefficient practices, providing some motivation to turn off the tap on our flow of pollution.
Misconception 8 – Cold regions are unproductive and house few living beings. Whilst this may be true on land, out at sea some of the most biologically productive waters are in cold regions where deep water rises to the surface and brings with it a cloud of nutrients. Antarctica, for example, brims full of life as whales from around the world migrate thousands of miles to these icy waters to feed on tiny krill which live around the ice shelves. Joining them are seals, penguins, seabirds, sea squirts, feather stars and hundreds more.
Misconception 9 – There is only one solution to the plastic problem. If we really want to take on the battle against plastic, then there really is no single solution which will bring us victory. Initiatives depend on the location, the community, finance available, the specific problem, the type of plastic and many more factors. So plastic taxes, beach cleans, recycling, return schemes and redesign will all be needed in different areas of the world or in regards to various types of plastic product.
Misconception 10 – The seabed is flat and slopes downwards towards the centre of the ocean. The seafloor is actually very similar to our landscapes above the waves and is filled with aquatic alter egos of mountains, deep canyons, flat plains, trenches and rainforests in the form of coral gardens. The Mid-Atlantic Ridge is an undersea mountain range stretching North to South for 10,000 miles whilst close to the coast of California lies Monterey Canyon, a 1.5 kilometre deep void which is comparable in size to the Grand Canyon.
Misconception 11 – The salt in seawater is like table salt. The scientific definition of salt is actually fairly broad and so all minerals which are washed from the ground into the ocean via rain or snow melt add to the salt in the sea. So, our oceans do contain lots of sodium and chlorine but also magnesium, calcium, sulphates and potassium.
Misconception 12 – Plankton are small and insignificant. Plankton, despite their tiny size, are actually essential in our oceans as they form the base layer of our food chain, with animals of all sizes feasting on these critters, from fish to shrimp to blue whales. Phytoplankton are also incredibly useful in limiting climate change as they absorb vast quantities of carbon dioxide which then gets stored in the ocean safely out of our atmosphere.
Misconception 13 – Living inland means you do not have any impact on the ocean. Whilst living far from the coast may make the dwindling state of the ocean seem less relevant, inland dwellers still have a massive impact on our blue planet. Pretty much everyone on the planet uses plastic and this plastic can wind its way into our oceans either from poor processing at large plants and landfills or via the wind, rain and rivers if it is dropped on the ground. In fact, one of the most common sources of ocean litter is cigarette butts which are dropped on town streets and then washed into storm drains during the next downpour and carried out to sea. So whilst you may have a negative impact wherever you live, you can also have a positive one by reducing your consumption of single-use plastic or carrying out a litter clean in your community. You can easily influence other threats facing the ocean too by choosing to eat sustainable seafood and by reducing your carbon footprint to play your part in reducing the effects of climate change.
Misconception 14 – Corals are mineral deposits, fossils or rocks. Despite looking a lot like colourful rocks, corals are actually living beings. Each delicate branch is made up of tiny invertebrates called polyps which then collect calcium carbonate from the surrounding seawater to build a hard skeleton to protect themselves. They even have a small mouth surrounded by stinging tentacles which they use to catch food passing by in the water.
So there you have it, a few of our largest ocean misconceptions debunked along with some fun facts which may help you at your next quiz night. Now that you know a little bit more about the ocean, do you want to help protect it even more?
By Neve McCracken-Heywood