The importance of biodiversity

And why  you should care about coral reefs

In a nut shell, richly varied ecosystems make for strong networks of healthy animals, plants (and humans), who can survive when faced with disease, individual extinctions and changes in climate. On a global scale, ecosystems become entwined in the web of life and all of us rely on this web to survive, even the most of us who live in cities. 

The Brazilian rainforest as a richly varied and diverse ecosystem, and losing one minor species might not affect that particularly diverse environment in a major way. But the effect will most certainly be to weaken it, and will never be positive.

But if you lose one species essential to almost all of the inhabitants’ survival, like the trees, then you are looking at potential collapse of a whole environment. And that can cause tremors of repercussions on a far greater scale.

Coral Reefs

Coral reefs are immensely diverse ecosystems, and like rainforests, they play vital roles in global climates. The corals are so integral to the reef, they are like the trees in a forest. Without them, that ecosystem cannot survive.

Corals are animals and they provide so many functions on which marine life depend, such as shelter, food, cleaning stations and nurseries for juvenile fish like whales- just for example. Around 25% of all marine life in the oceans rely on coral reefs.

But reefs are being systematically destroyed by sea temperature rises as a direct result of pollution from Carbon Dioxide usage. When the ocean temperature rises, even by just 2°, this causes corals to bleach.

Bleaching is a sign that the coral is dying. The coral skeleton is what can be seen when this happens and it will change from a variety of healthy colours to various neons, to white to brown and covered in algae. And as it has been pointed out to us in the documentary ‘Chasing Coral’, “dying reefs are a sign of unhealthy oceans.”

Mass coral bleaching, notice the lack of fish. Image source unknown.

After the El Nino of 2015, whole reefs have been collapsing and the Great Barrier Reef in Australia lost a whopping 29% of its corals in 2016 alone. That’s about equal to losing all the trees in the UK.

And this is not just one animal at stake but all the anemones, angelfish, clownfish, starfish, squid, wrasse, grouper, cuttlefish, sweetlips, nudibranchs, parrotfish, triggerfish, eels and flora like seaweed, kelp, mangroves, sponges, sea cucumber, seagrasses, which all live and depend on that reef.

Then there’s the larger residents and visitors like schools of fish, turtles, manatees, sharks, rays, manta rays, dolphins, octopus and whales which come to be cleaned, to prey and, as we’ve seen in many a David Attenborough documentary, to nurse their young in the shallow, warm waters.

manta-ray-ryan-jeffery frazer island - cleaning
Manta Ray at a cleaning station, Frazer Island, Australia. The fish are eating parasites from wounds and scratches on the Ray.  Image by Ryan Jeffries

All of these marine animals and plants depend on the coral’s ability to thrive because the web of food and life here is so intertwined, from the smallest creatures to the largest predators. Billions of humans across the world also rely directly on the health of reefs for food and income, from fishing and tourism.

The Great Barrier Reef is the largest living structure on the planet and just one example of global coral reefs negatively impacted by threats to biodiversity mainly caused by human activity.

Why is biodiversity on the GBR threatened?

A recent article in the Guardian stated that whole sections of the Great Barrier Reef are in collapse. Why? [hyperlink-

Ocean acidification, sea temperature rise, pollution, trawler nets, tourism, overfishing, drilling for oil, natural disasters like cyclones, and the exotic animal trade are all significant threats to coral reefs.

One of the major problems is ocean acidification. Ocean acidification happens as a result of excess CO2 absorption in to the oceans. This then causes sea temperatures to rise because CO2 is very good at trapping heat.

Chasing_Coral_dying coral
Corals dying on the Great Barrier Reef

One of the main things oceans do is to create oxygen just like trees, but now that co2 levels are higher than ever, the oceans’ capacity to convert it back to oxygen is being tested. And overfishing, chemical run off from farms and plastic pollution in the oceans (to name just a few) are all putting additional pressures on the oceans’ ability to produce the air we need.

Sea corals thrive in very specific conditions. They like lots of sunlight so they can photosynthesise and need clear water to do that. Temperatures need to be between 23° and 29° C. Anything below or above this and they begin to die/don’t grow at all. Some corals can survive in temperatures as high as 40°, but only for a short time. And sea temperatures have been rising above 29°C consistently with global warming rates for the last few years, with bleaching happening since the 1980s.


What happens to the reef when coral dies?

The next thing to go is the fish and marine inhabitants, which have either died as well or moved on. By this stage, the reef is already in to collapse, as the cycle of visitors will not be attracted to the reef to feed or clean.

But where else can they go?

Most marine life are internally programmed to visit particular areas to eat, mate and clean. It is an evolutionary behaviour learned over millennia and not something as easily changed as shopping at a more ethical supermarket (ahem).

Expecting an animal to just change where they feed and sleep as a result of our destructive habits, would be like expecting an old lady, who has lived in the same house all her life to move house to make way for a fracking site.

chasing coral, still
A school of blue fin tuna on a bleaching reef. Image from Chasing Coral.

Leatherback turtles visit reefs in Malaysia to mate every year, travelling thousands of miles from their feeding grounds. The females then climb the beaches to lay their eggs. If they haven’t been poached by humans or predators by the time the eggs hatch, the baby turtles – about 100 in a nest- then have a mad dash back to the sea, trying to avoid being eaten on the way by birds and lizards, where they have a one in 10,000 chance of survival to sexual maturity 30 years later when the whole process starts again.

But Leatherbacks are critically endangered as a result of habitat loss to tourism, such as lights across beaches which scare off mothers and confuse hatching babies. Now with the pollution and destruction of reefs all over the world the noose has tightened even more around the survival chances of these iconic animals and their countless neighbours.

The answer?

Basically we need to stop treating the seas like it’s the world’s toilet.

If we can protect oceans, halt ocean pollution and limit/completely stop our reliance on fossil fuels, we may be able to save these essential ecosystems.

Great-Barrier-Reef-Turtle-Wallpaper healthy
A Hawksbill turtle glides over a healthy reef. Image courtesy Google Images


How you can help  

  • Stop using bleach and other products that pollute water.
  • Avoid unnecessary plastics such as single use and NEVER use products containing micro beads.
  • Don’t drive your car unless you can’t avoid it.
  • Switch to an eco-friendly energy provider.
  • Limit your consumption of fish or even stop eating it altogether.
  • Know where your fish comes from and don’t believe labels that simply state something is ‘responsibly sourced’ when there’s no evidence to prove it.
  • Donate to environmental charities and get involved in campaigns.
  • Think hard about whether you want another child. Population growth is a major driving force in climate change. Having one less child would save around 9,441 tons of CO2.
  • Share this information with your friends and family. Word of mouth is so powerful and the more people who know and use this knowledge, the greater positive impact we can have.

Remember, there is still hope, we can still turn things around, but we have to do it together and we have to act now.


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