Human Interaction

Fisheries management programs are necessary for a sensible shark harvest.

Only the United States, New Zealand, and Canada have started shark management plans.

On April 26, 1993, the National Marine Fisheries Service (NMFS) implemented a plan to manage U.S. shark fisheries of the Atlantic Ocean, Gulf of Mexico, and Caribbean Sea. The plan included the following features:

• Yearly commercial limits, which are divided into semi-annual quotas.
• Provisions for closing a fishery for a species group when the semi-annual quota is met.
• Catch limits for recreational anglers.
• Permit requirements for commercial vessels that catch sharks.
• A requirement that vessels land fins in proportion to carcasses (effectively prohibiting the practice of shark finning).
• A requirement that when sharks are not kept, they are released in a manner that ensures the probability that they will survive.

The state of California passed a law in 1993 totally protecting the great white shark.

The law set forth by NMFS placed limits on 22 species of large coastal, seven species of small coastal, and 10 pelagic species of sharks. A yearly catch limit of 5.4 million pounds of sharks still failed to stop declining shark populations. In the spring of 1997, NMFS cut the quota of large sharks to 1.285 metric tons, limited the catch of small coastal sharks, and banned the commercial harvest of whale, great white, basking, sand tiger, and bigeye sand tiger sharks (Odontaspis noronhai).

Future research into population dynamics of commercially important shark species will yield important information about longevity, reproduction, and growth. The information can be used to design effective fisheries management programs.

For more information see Longevity & Causes of Death.

Research

The piked dogfish may be the most numerous shark, since an estimated 27,000,000 were fished off the Massachusetts coast each year. Yet, many species such as the combtoothed lanternfish (Etmopterus decacuspidatus) are known only from a single specimen. The bizarre goblin shark (Mitsukurina owstoni), with its odd pointed snout, was not discovered until 1898. For many shark species, even basic information about them is rare.

Scientists would like to know more about sharks, especially their behaviors and learning capacities. In experiments, nurse and lemon sharks showed surprising abilities to learn, recognize, and remember different shapes and sound cues. Sharks are proving not to be the mindless creatures once depicted in the past.

Recent studies have also shed light on shark behavior. As the name would suggest, nervous sharks (Carcharinus cautus) are timid and skittish when approached by divers. Greenland sharks are so sluggish that they can actually be lifted out of the water without any resistance. But many other species readily investigate humans in the water as if out of curiosity.

An increasing area of study is in the development of shark repellents and protective dive gear.

A chain mail suit made of 400,000 tiny, interlocking stainless steel rings (price tag: around $5,000) proved effective against the bites of smaller sharks.

The opposite extreme of this is the fundoshi, a long, thin red cloth that female Japanese divers wear around their waists. The divers believe the fluttering tail may scare some sharks away or divert the shark into biting the cloth.

The state of California passed a law the same year totally protecting the great white shark.

One especially promising device is called the Shark Screen. The Shark Screen is like a plastic sleeping bag that floats in the water. Most shark attacks on humans occur on easier targets like arms and legs. A person inside the Shark Screen has the advantage of appearing as one large mass to a shark, with no easy targets to bite. Also, body chemicals and blood cannot escape into the water to attract sharks.

SeaWorld Parks & Entertainment and the Hubbs/SeaWorld Research Institute study sharks and educate the public on their vital role in the ocean environment.

The education team at SeaWorld conducts dozens of classes, tours, camps, and hands-on encounters that show guests the importance of sharks. ShamuTV, a distance learning program, provides classrooms and homes around the world with an up-close look into the world of sharks and other animals.

The SeaWorld & Busch Gardens Conservation Fund (SWBGCF) supports projects to protect sharks around the world. Little information exists, for example, on the Puget Sound’s sixgill shark population. The SWBGCF has funded studies on the migration patterns, population status, sizes, and age/genders of these mysterious sharks.

In China and Central and South America, the SWBGCF and WildAid’s Shark Conservation Program teamed up to elevate the importance of conserving shark populations from finning practices. Numerous laws have been strengthened to protect sharks, and there has been a decrease in the amount of shark consumption in key Asian countries thanks to this effort.

In Belize, the Meso-American Reef area is being threatened by unregulated tourism, over-fishing, and agricultural runoff. A grant by the SWBGCF is helping to bring neighboring countries together to discuss ways to conserve this vital area. Such funding helps to protect shark species, such as the whale shark, as well as all of the other marine life found in this the second largest barrier reef system in the world.

Sharks have a value far beyond human economics. Perhaps the greatest challenge with shark conservation is convincing people of the need to protect them.

Often sharks eat sick and weak prey. This actually improves the gene pool for the stronger, healthier individuals that go on to reproduce. Shark overfishing removes this vital link in the delicate balance of the ocean ecosystem.

When sharks were overfished around Australia, the octopus population increased dramatically. The octopus then preyed heavily on spiny lobsters and decreased that population, causing hardship to local lobster fishermen. By destroying sharks, humans may unwittingly be removing a key that keeps the populations of countless ocean creatures healthy.