- Identify basic concepts of shark classification
- Identify components of shark anatomy
- Identify basic concepts of shark physiology
- Identify different forms of shark behavior
- Identify components of shark interactions
- Identify different species of sharks
Sharks are a vital component of marine ecosystems; as apex predators they control their prey populations: stabilizing population fluctuations and removing diseased or genetically flawed individuals. Their disappearance can be extremely damaging.Nevertheless, sharks are being subjected to intense fishing pressure as a result of the high demand for shark fins and cartilage. Since many sharks travel long distances, crossing oceans and national boundaries, they are susceptible to the unregulated fishing efforts of multiple nations. Consequently, shark populations have plummeted worldwide to less than 30 percent of their numbers two decades ago. This decline, coupled with the slow reproductive rate of most sharks has meant that there is now considerable concern about the health of shark populations and an urgent need for effective conservation and management.
There is a well-documented history of shark stocks that have undergone a brief period of fisheries exploitation followed by a sudden collapse in yield. Examples of collapsed shark fisheries include the porbeagle (Lamna nasus) fishery in the North Atlantic, the soupfin shark (Galeorhinus galeus) fishery of California, various basking shark (Cetorhinus maximus) fisheries, and the spiny dogfish (Squalus acanthias) fisheries, both in the North Sea and off British Columbia. All unregulated targeted shark fisheries have been boom and bust endeavors. This is marked by a relatively short period of booming business, which is followed by a rapid decline in catches and a long period of either slow recovery, or no recovery at all.
The increase in demand for shark fins in the Asian markets has further increased the exploitation of sharks around the world. Shark fin soup is a delicacy in Asian restaurants where it is reported that a bowl of shark fin soup can cost as much as $250 per bowl, depending on the amount and type of shark fin used in the soup. Many times the sharks are finned, a practice whereby the fins are removed from the shark, while it is still alive, and the body is thrown back into the sea. The fins are the most valuable part of the shark and thus the fishermen would rather fill their boats with fins rather than the less valuable shark meat.