Sharks are an amazing example of evolutionary design success, according to Mahmood Shivji, director of the Guy Harvey Research Institute at Nova Southeastern University.
“They have been around in various shapes and sizes for over 400 million years, making them much older lineage than even the dinosaurs,” he said.
“There are approximately 500 known shark species currently worldwide, and likely to be more species discovered in very deep depths.”
This is one of many reasons Mr. Shivji has dedicated his professional life to protecting the animals, most recently by helping Guy Harvey launch a new campaign to protect shark species in the Bahamas.
Mr. Harvey is working with the Pew Environment Group and the Bahamas National Trust to enact legislation that prevents commercial fishing in the region.
“Sharks need to be protected everywhere including here in the Cayman Islands,” Mr. Harvey said.
“The Bahamas has more sharks than any other country in the western Atlantic because they banned long line fishing within their 200 mile Exclusive Economic Zone over 20 years ago. Long line fishing has caused the indiscriminate annihilation of sharks, billfish turtles and seabirds around the world, except in places where it is banned.”
He explained that sharks are slow growing fish that reach maturity at a late age and live a long time.
“Animals with this reproductive strategy do not last long when heavily extracted,” he said. “Every single shark fishery has not lasted for long because the fishing of sharks is unsustainable.”
Now there is a large market for dried shark fins in Asia that is causing this overfishing, according to Mr. Harvey.
“The practice of shark finning is a barbaric technique of catching sharks, cutting their fins off while they are alive and throwing the body back into the sea,” he said.
“There is pressure from Asian countries to obtain permits to fish the shark population. It would lead to an irreversible demise of the sharks in the Bahamas, and the government realizes this.”
Mr. Shivji describes sharks as animals that are often misunderstood, but always fascinating.
“As predators living in a three-dimensional, complex environment, they have highly developed senses of smell and vision that we recognize but still don’t yet fully understand,” he said.
“They come in a wide range of adult sizes, from approximately 17 centimetres in length (a type of deep sea lantern shark) to the biggest fish in the sea, the whale shark, which can get as big as a 1,000 centimetres in length.”
Only a dozen or so sharks get bigger than 450 centimetres in length, according to Mr. Shivji.
“Sharks have no true bone and their skeleton is made up of cartilage (like in human noses), giving them tremendous flexibility,” he explained.
One shark fact that is not commonly known is only about half a dozen of the approximately 500 known shark species have been implicated in bites on humans.
One of the myths about all sharks is that they hunt humans, when in fact there have been very few cases of shark attacks and only from a few species. In the Caribbean, sharks play a vital role in tourism and the reef systems.
“Living sharks are worth hundreds of thousands of dollars over their life time in ecotourism, versus a few hundred dollars as fins and meat in a one-time catch,” Mr. Harvey said.
Interacting with sharks has become a major tourist attraction for both divers and non-divers. “For example, just in the Bahamas, shark diving related tourism generates about US$78 million a year,” Mr. Shivji said.
“Such shark tourism operations are becoming widespread in many parts of the world.”
Shark species like the Caribbean reef sharks in the Atlantic, and whitetip and blacktip reef sharks in the Indo-Pacific are specialized to living in and around coral reefs.
“As top-level predators on reefs, they play a key ecological role in keeping the entire reef ecosystem in balance,” he added.
Mr. Shivji said he gets a personal satisfaction in protecting sharks. “Sharks are a marvel of evolutionary design and longevity,” he said. “As key ecological species, the presence of healthy shark populations is integrally tied to keeping marine ecosystems functioning normally.
“They deserve our respect and protection for the remarkable creatures they are, their key ecological importance in keeping our oceans balanced and healthy, and their great vulnerability to overfishing.”