The Unsung Heroes of Our Ocean Planet

We so often see the huge eyes and fluffy faces of endangered pandas, tigers and monkeys staring up at us from adverts and flyers, each and every one melting our hearts while we convince ourselves we will do something to help keep them roaming the planet. Nevertheless, when was the last time you saw a shark staring back at you, or an octopus or even just a brightly striped fish? For a long time, conservation campaigns have tugged on our emotions to raise funding, with the cuter, rarer and more impressive species stealing the spotlight. These iconic animals are often known as charismatic megafauna. While they still front our campaigns, zoos and conservation groups are increasingly focussing on other, more functional species which contribute essential skills to their habitat and under our current extinction threat, provide the best chance of survival for our ecosystems. Marine species barely even swim their way onto endangerment posters, with only three of the top 20 charismatic megafauna living in the deep. There is so much unknown life beneath the waves, with scientists estimating that for every species of marine life we know of, at least three others are yet to be discovered. So who are the unsung heroes of our ocean planet?

Throughout Earth’s turbulent history, there have been five major mass extinctions; the largest resulted in the loss of 96% of marine life as the atmosphere was ramped up to a greenhouse state. Many argue that we are currently in the sixth mass extinction as humans have accelerated the natural rate of extinction by over 1,000 times as we hack away at rainforests, meddle with natural systems and happily burn away fossil fuels. It is for this reason that focussing on functional species which can create positive change in their ecosystem is essential as it will protect a wide range of biodiversity and mitigate our destructive actions.

Surprisingly, the most functional species in our oceans cannot be seen with the naked eye. Plankton, meaning wanderer, float under the radar for most yet these are the most abundant form of life in the ocean both in terms of weight and sheer number. Phytoplankton are tiny plants which form the very basis of the food chain while also generating massive amounts of oxygen and greedily consuming our carbon dioxide. Yet this is only the start of these eco-warriors’ work reversing climate change. Phytoplankton release particles called dimethyl sulphide (DMS) as a waste product during their life. These particles float to the surface where they evaporate into the atmosphere. Once free in the atmosphere, water droplets latch on to create clouds and the more DMS particles there are, the less sharing water droplets have to do as they spread themselves out across the sky. This spreading causes clouds to be whiter which in turn reflects more sunlight back out into space and away from our planet, thus cooling our environment. While this alone is no match for our power stations and traffic jams, these little critters are doing more than their fair share to further our sustainable pursuits.

The 7,000 algal species, including all seaweeds, have also hopped on this climate-saving bandwagon as marine plants produce between 70-80% of the oxygen present in our atmosphere. Tangled underwater mazes of kelp forests can grow up to 2 foot a day and provide an essential store of carbon; often even dead pieces of kelp and their carbon are stored safely under the thick muck on the seabed. Kelp forests are a source of both shelter and food for species such as fish, sharks and crabs yet they would flounder without sea otters. Sea otters are a keystone species, they are individuals which define an entire ecosystem and all its organisms; the social influencers of the sea. Often keystone species are not the most common in an environment and so each and every one counts. In these tousled forests, otters feed on sea urchins and control their population numbers; without this natural regulation, sea urchins would run amok, devouring kelp and destroying the safe hiding places for fish. These undeniably adorable otters also improve the productivity of the kelp itself, with their presence increasing the annual carbon uptake of seaweed by 4.4-8.7 megatons, the equivalent of 3-6 million cars!

Other keystone species include parrotfish which are the caretakers of the reef. Each hungry fish can nibble away up to 4,500 kilograms of algae each year which leaves the corals free to bask in the sunlight and gain their daily vitamins. While sharks are depicted as the devil from the deep, they actually often scavenge for leftover food, eating up the dead carcasses floating amongst the waves which stops bacteria multiplying in ocean environments. They also keep fish populations in check, making sure no one species gets too popular and upsets the delicate balance.

The last type of species we should consider over their fluffy counterparts is indicator species. These creatures help us assess our impact on the ocean and provide an essential port of call in scientific research. Marine invertebrates, those lacking a backbone, are underrepresented in conservation yet they form a whopping 92% of marine life, playing a crucial role in sustaining food chains but due to their lack of public appeal, have failed to gain legal protection unlike many marine mammals. Giant squid are the largest marine invertebrate, stretching up to 59 foot long and can weigh almost a ton! Yet these giants are increasingly emerging from deep sea canyons as warmer, more acidic waters are causing them to migrate towards the surface where their blood fails to adapt to high levels of oxygen, meaning squid strandings now highlight the severity of climate’s impact on the ocean. Oysters, clams and mussels are important indicators to help us gauge the level of plastic pollution in our oceans and therefore aid in assessing our wasteful habits. These organisms take in water, absorb any tasty treats and then expel the remaining water back out but in our increasingly plasticised world, microplastics and microbeads are taking the place of food in their tissues. This is causing a decline in reproduction as the little energy they gain from natural food is fed into growing their shells, not creating offspring.

All these incredibly intelligent and useful species fail to make the covers of magazines or the lead role on TV, and we haven’t even touched on the weird and wacky deep-sea creatures including the piglet squid, red-lipped fish or the blobfish. So while our gentle giant whales and majestic manta rays can, and should, still inspire awe within us, spare a thought for the forgotten heroes who tirelessly work to make our planet a better place, even when all our actions seem to do is disturb their home.

By Neve McCracken-Heywood

Rory Sinclair