The ecological ValuE of sharks

Sharks keep marine ecosystems in balance

That balance is the product of thousands of years of evolution and adaptation.

Ecosystems are finely tuned systems that are based on many species. All members play an integral role. The top predators are critical in keeping ecosystems in balance. The ocean needs apex predators. 

A natural balance is nearly impossible to recreate once it has been destroyed. 

Because sharks are very slow to mature and will only have a small number of pups a year (or every other year), population sizes of sharks don’t recover easily once they have been decimated, unlike other schooling fish such as tuna, which hatch thousands of eggs every year. 

It is estimated that even if all commercial fishing were to cease, many of the large sharks may not recover within 50 years, if ever. As apex predators, sharks are not equipped to withstand predation themselves and are highly vulnerable to exploitation.

Sharks keep our oceans healthy and strong

Sharks stop disease from spreading by preying on the sick and dying. They keep populations strong and vibrant by taking out the weak and slow. Sharks are the major driving force behind natural selection in the ocean realm. Their presence often dictates the behavior of other species, which in turn regulates how reef fish, sea turtles, and other grazers behave. And that has consequences for how healthy reefs and sea grass beds are maintained. 

There is no other animal (including humans) that can do the job sharks perform so perfectly. Sharks and rays have evolved into roughly 500 different species, each of them adapted and specialized to function in a particular niche and layer of the ocean world.

Other fish need sharks

Fish stocks that we like to catch and that all of us count on for food also need sharks. It may seem counterintuitive to see a predator as anything else than competition. After all, they eat the fish we want to catch, right?

Wrong! For example, without the control of sharks, populations of smaller predators can rapidly increase, which may seem like a good thing for people who want to catch more fish. However, the problem is that the consequence of too many small hunters can cause the opposite effect. They may eat too many reef fish, which are also priced as food fish. And without reef fish that graze on coral reef, algae can quickly overtake the reef. Coral polyps die when covered by algae. The reefs are the birthplace for most fish (even the pelagic ones like tuna) – No reef, no fish, no fishing.

Additionally, once the smaller predators have depleted their own food source, their numbers will drastically diminish as well. The end result – no one wins. This is just one example of how the system gets disrupted by taking away the top predator. 

The food chain needs all links intact