Earth Day, Sharks and Coral Reefs. Are they connected?

 Earth Day is fast approaching. Shark populations are dwindling and, in some cases, nearing extinction. There are reports that the Great Barrier reef is losing its ability to recover from another bleaching incident. How are all these events related. Well, read on my friends.

Look at this picture of the plant we call Earth. See anything that strikes you? Like all that blue water? The Ocean covers over 70% of the plant, and yet we call it Earth Day. I won’t go into the history of Earth Day, you can do that for yourself. And yes, taking care of our precious “land plant” with recycling and other wonderful things is awesome. But what about “Mother Ocean”?

earth day

Well, in honor of Earth Day, let us consider the apex predator of the Ocean and what losing sharks means to us all.  Sharks are often the top of the food chain in their eco system. They remove the weak, injured and sick of many different species. Sharks that reach adult hood have few predators. So, think of the Ocean as a huge food chain. Big fish eat smaller fish, and so on. But if we remove the apex predator what happens? Simply put, fewer apex predator mean more lower level carnivores which leaves fewer herbivores which then leaves more macro algae. I am sure as divers you have seen more algae on the reef. That algae is smothering the corals. And with less corals we have other issues coming from the sea.

For Earth day let us try and understand what this means. Studies of remote reefs have revealed ecosystems that are very different from those we know today.  Yes, humans are creating major issues both on land and at sea.

A study of reefs in the Northwestern Hawaii Islands found that apex predators, including sharks, comprise over half of the fish biomass compared to less than 10% on reefs that are fished. On the unaltered reefs the sharks are bigger and populations of all species are far greater. Additionally the unaltered reefs are home to a larger variety of other species than regularly fished reefs.

yes that is a fishing hook in the sharks mouth

The presence of sharks can also protect seagrass beds from over-grazing by dugongs and green sea turtles. These animals prefer to eat in the middle of a sea grass bed where the quality of food is the highest. But it is harder for them to escape a hunting shark from the middle of a large seagrass bed, so they stay on the outside when sharks are present. Seagrass beds are an important habitat for many fish and invertebrate species.

So for Earth day let us expand our thoughts to “Mother Ocean”

Celebrate Earth Day

So, yesterday was Earth Day, a day to celebrate earth and support environmental protections that was first started in 1969 with the actual first Earth Day in 1970. It was mostly an American event and largely acknowledged by the youth and in Universities until 1990 when Earth Day went “global”. For many it is a reminder that we need to protect our resources and Earth Day is largely responsible for many of the recycling projects that many people start in their own homes, but what I noticed yesterday is how many of the post to social media and even in the evening news was only about earth and not water. In other words it was all about the less than 30 percent of the surface of the earth.

earthdayWe celebrate Earth Day as a reminder to take care of our planet every year, but we largely ignore the ocean. After all, the ocean covers over 70% of the planet and gives us so much in the way of food and energy and yes even entertainment. In 2000, research showed that 11% or the planet’s coral reefs were damaged and degraded beyond recovery and in 2004 just about 20% of the reefs were dead. We are slowly losing a major player in maintaining our biological diversity as the coral reefs die off due to pollution and other factors.  One such factor is the new deep water port for the cruise ships just off Palencia in Southern Belize. Yes, we celebrate Earth Day; but we forget about Mother Ocean.

If you haven’t downloaded the free book from Project Aware’s website, I will encourage you to do so. Just 115 pages it is an easy and quick read and yes you can even earn a PADI specialty afterward, but the book is very enlightening about our water covered world.