Shark Hunting Shark Hunting and Commercial Fishing For thousands of years, sharks have been considered to be highly protein food, with great commercial and even recreational value. Shark fishing is a very popular activity around the world, for various purposes.
Messenger New South Wales is the latest Australian state to hear calls for sharks to be culledin response to a spate of fatal and non-fatal incidents. Put simply, there is no scientific support for the concept that culling sharks in a particular area will lead to a decrease in shark attacks and increase ocean safety.
Western Australia tried culling sharks with baited drum lines last year. The tactic did not improve the safety of swimmers, surfers or divers — one of the reasons why scientists actively opposed the cull. A similar long-standing policy in Queensland has shown little evidence of effectiveness.
Born survivors Sharks have inhabited this planet for more than million years, and have survived five mass extinctions. Sharks are especially vulnerable because of their low reproductive rates, slow growth and delayed rates of maturity.
As apex predators, they maintain community structure and biodiversity by regulating predator and prey abundance. Even light fishing pressure such as species-target line fisheries can cause dramatic declines in populations of large coastal sharks. Meanwhile, indirect fishing via shark meshing programs can catch a range of targeted and non-targeted species of sharks.
Shark culling is best thought of as an indiscriminate method of removing sharks from our coastal ecosystems. The WA and Queensland culls have led to the capture and death of many non-targeted sharks. Similarly, spinner and dusky sharks have very low survival rates within the first few hours of being hooked, and sharks that are hooked and subsequently released do not necessarily survive.
Hooking in the gut is very common. Stainless steel hooks do not rust out but become encapsulated in the tissue over time, causing starvation, wasting of the body known as cachexiaand eventual death.
If we remove sharks as top predators from the ecosystem, the effects will filter down to animals lower down the food chain and cause unexpected changes to ecosystems. We are already seeing such changes in areas where sharks are overfished. Declines in the number of blacktip sharks in North Carolina in the late s and s caused an increase in the relative abundance of cownose rays and a corresponding decrease in scallops over the ensuing decades.
Healthy aquatic ecosystems are typified by a complexity of players in the food chain, and removing such macropredators will result in decreasing ecosystem resilience. What can we do instead of culling? Indiscriminately culling sharks is dangerous to marine ecosystems, not to mention expensive and futile.
We would be far better off allocating resources to achieving a greater understanding of the ecology and behaviour of these large predators. We can increase knowledge of why and where sharks are likely to attack humans by tagging sharks and following their movements over timeor through genetic studies that can assess effective population sizes.
Current aerial surveys are unlikely to be a successful strategy, however. Scientific analysis has already discredited aerial programs in NSW. Aerial surveys have only a As surveys are only done for a few hours per week, and pass over a particular beach in minutes, these patrols can give the public a false sense of security.
Other non-invasive methods of mitigation are currently being developed, including the use of erratic walls of bubbles to deter sharks, and the development of wetsuits and surfboards that sharks are less likely to mistake as prey. But ultimately, we also need to take personal responsibility, and reduce the likelihood of an attack by not swimming at dawn and dusk, not entering the water at the mouth of estuaries with poor visibility, or in areas of baitfish.
After all, even sharks can make mistakes.There are many reasons why you need to eat healthily: be in a good mood, decrease weight, become more productive, become healthier, etc. You can tell about the pros and cons of electric cars and make the accent on disadvantages.
In practice, electric cars don’t cause pollution directly. Why do we need to stop tipping waiters? In fact. Do we need to cull whales?
International opinion on commercial whaling; Conclusion; Download a printable version of the ‘Why Commercial Whaling must End’ report. Introduction. Since the indefinite commercial whaling moratorium was introduced in , the whaling nations have killed around 15, whales between them.
States Andersen, “If we can put a man on the moon, we certainly can determine a method to ensure sharks and humans can peacefully coexist in the shark’s domain.
Programs like the Shark Spotters in South Africa prove that there are viable alternatives to shark nets . The ocean is our domain and sharks have no place destroying lives and livelihoods; these predators are lurking out there ready to cull humans and we as a community must find a permanent solution.
Early man hunted whales because their meat and blubber were able to fulfill his basic survival needs. For thousands of years, the climate was too cold for many people, including the Eskimos and the indigenous people living in Greenland, to grow their own vegetables.
In biology, culling is the process of segregating organisms from a group according to desired or undesired characteristics. In animal breeding, culling is the process of removing or segregating animals from a breeding stock based on specific trait.
This is done to exaggerate desirable characteristics, or to remove undesirable characteristics by altering the genetic diversity of the population.