Featured Image Credit: Plymouth Herald
By: Kira Krall
There are over 350 species of distinct shark species in the world, including the largest fish in the oceans, the whale shark. Most of the time you’ll find them eating meat, but some species will dine on marine greens if the occasion calls for it (just hold the dressing).
Because of their diet, sharks are a vital link in the marine food web. They control the populations of other animals in their habitats. They even increase the health and fitness of different species by predating on the old, sick, and generally unfit individuals. Coral health is dependent on the sharks’ ability to help maintain diverse, herbivorous fish populations.
Photo Credit: Source
Sharks work a little bit differently than other gill-bearing ocean creatures. They have a body built for speed and fins that give them power and stability. They have a phenomenal sense of smell and an additional sixth sense: Their noses have ampullae of Lorenzini, which are basically pores filled with a special kind of gel that senses electric fields and temperature changes.
Most sharks, excluding some species like the nurse shark, cannot actively pump water over their gills and have to keep moving in order to breathe. That’s hard to do when you’re trapped in a net.
Sam Provstgaard Morys went snorkeling off the coast of Massachusetts and found the monofilament graves of the small-spotted catsharks in the picture below. The net was a ghost net, or a piece of fishing equipment that was discarded by fishermen. Sometimes they are accidentally lost and sometimes they are intentionally left behind, but either way, their impact is the same.
Photo Credit: Source
Sam Morys removed the net and the 9 shark carcasses contained inside it from the ocean. Theonly way to reduce the impact of ghost gear is to physically remove it.
Ghost nets aren’t just a threat to sharks. Other marine species like sea turtles, birds, and dolphins can get trapped, too. There are 85,000 ghost crustacean traps in the Florida Keys Marine Sanctuary alone. Much of the ghost gear in the ocean is the result of illegal fishing. Even legitimate lost or discarded gear is grossly underreported.
Photo Credit: Save Our Seas Ltd./Tom Campbell-Marine Photobank
Shark populations have decrease by about 90% because of one reason (you guessed it): humans.
As many as 180 sharks were killed out of fear last year during Western Australia’s shark cull. The shark fin soup industry is responsible for killing an estimated average of 38 million sharks per year. The Central Pacific fishing industry is responsible for over 150,000 dead sharks per year as a result of bycatch, or the unintentional capture of a non-targeted fishery species.
It’s our responsibility to reduce our impact on these fascinating and vital creatures.
You can read more about ghost gear and learn about other forms of marine debris here.