How Humanity Influence on Animals

The rise in the human population has lead to a decrease in overall biodiversity. One prime example of how specific species are affected is the whale shark. The whale shark is a suction-filter feeder and is the largest extant fish-like vertebrate (Martin, 2007). They have laterally placed and small circular eyes. It is believed that whale sharks are capable of discerning movement at close range even though they have low visual acuity. It is mostly unknow on how they filter-feed and they possess acute olfactory sensitivity.

The inner ear of the whale shark is the largest known of all animals. This makes them the most responsive to long-wavelength and low-frequency sounds. They also experience ontogenic allometric changes between birth and maturity. Juvenile sharks have an elongated body, small fins, and a heterocercal caudal fin. Adult sharks have a sublunate caudal fin, large pectoral fins, and a narrow peduncle. Their segregation by sex and size is vast (Martin, 2007).

Whale sharks are vital to the food web and ecosystem and without them, the ocean and land will be immensely affected. Martin described two different interactions with the sharks; encounters with boats and encounters with divers. Whale sharks have been seen to evade boats by swimming deeper into the sea. This could be from the low-frequency sound the motor makes because it interferes with the sharks' migration routes and feeding/mating behaviors. Due to the increase in boats in the ocean, a change migration routes or the exclusion of important feeding or mating areas may occur because of the sharks trying to avoid the boats. However, restricting the number of whale shark charter boat licenses may help because it will limit boat noise and using propeller guards may reduce harshness of whale shark injuries due to collisions. Individual sharks vary in their response, some get close to humans while others adjust their swimming to avoid humans. It was found that the proximity of the swimmer to the whale shark was a great predictor of the shark changing direction, the whale shark is less likely to change directions with each additional meter away from the swimmer (Martin, 2007).

Some individuals also allow humans to touch them without showing any signs of distress, while others become stressed with contact and respond with defensive behavior. Long-term consequences of this might include exclusion from critical habitat (Martin, 2007). Previously, whale sharks were of little interest to humans because it was nonthreatening and was not useful for consumption or products. Whale meat was wanted in Taiwan and it was described as similar to tofu and was pricy. The landing of 40 whale sharks over a 4-day period was recorded in 1982 from a fishery in India. The carcasses were discarded once the liver was removed due to no desire for the flesh. In China, the oil from the liver was desired because of the possible anti-tumorigenic properties. In other places around the world, whale sharks were killed for their liver oil and their fins. Sometimes they would get caught accidently in gill and purse seine net fisheries. Usually they would just be discarded because there was no use for them. Some tuna purse seiners watch for whale sharks and put a net around them to catch associated species that also eat plankton. The sharks are also at risk from being hit by vessels while feeding (Colman, 1997).

A key factor that will help sustain whale sharks-human interactions is understanding the population dynamics of them. When seasonal and interannual variability in abundance and distribution are known, long-term effects will be better known (Colman, 1997). The impacts on whale sharks from tourism has been researched and it is truly not a solution for the sharks. The effects can be direct or indirect and are mostly from the reoccurring human disturbances. Proximity, flash photography, touching, diving near, obstruction of path, and use of SCUBA equipment were the main factors that influenced the reactions of the whale sharks. The data was collected through the use of questionnaires that were distributed in two different locations and to the tourists. Gallagher stated that the human presence during wildlife tourism can have sublethal physiological impacts on the animals and this can lead to influences in important characteristics of animal functions. In previous research, predators have shown measurable stress responses to human presence (Gallagher et al., 2015).

Whale sharks are likely to change their path when humans are in their way or show aggressive behaviors when touched. Species can also get physically damaged through human interactions. Whale sharks have obtained scars due to collisions with boat propellers. Some tourist places allow staff and guests to handle or manipulate the sharks and this can affect shark physiology or homeostasis. Some places put the sharks into 'tonic immobility' to impress the guests, but this exercise has been shown to cause physiological and biochemical disturbance and an increase in stress levels. Human interactions could deter the sharks from completing critical behaviors. Improper operator handling could cause a false impression that sharks are aggressive. Boats cause noise pollution and physical obstruction that restrict behaviors like feeding (Gallagher et al., 2015).

Humans cause a rise in carbon dioxide, which in turn causes ocean acidification and global warming. This impacts marine life because calcium carbonate is formed and a disturbance in the acid-base physiology. The CO2 that is usually produced in cells during metabolism is hydrated to create bicarbonate and H+. This is a reaction catalyzed by carbonic anhydrase. Lower concentrations of ion transport proteins will cause a lower rate of metabolism. Marine animals rely on specialized respiratory proteins to bind oxygen to the respiratory surface and transport it the tissues for cellular metabolism. The normal gradient for the blood is not enough to facilitate sufficient oxygen saturation and unloading of the proteins (Fabry et al. 2008). The production of carbon dioxide causes acidosis which promotes the release of oxygen at the tissues. Species with high metabolic rates are the most impacted by acidification because the oxygen that binds to their blood is more pH sensitive. Ward-Paige found out through extensive research that sharks are largely absent on reefs in the Caribbean. Comparison with human population density shows that this is related to anthropogenic pressures (Ward-Paige et al., 2010).

Sharks are mostly found on the reef in areas with low human population density or in places with strong fishing regulations. Population viability analysis showed that low levels of fishing death rates cause shark populations to decrease and this alone could account for the absence of sharks. This is similar to other coastal and reef sharks. Of the species analyzed by Ward-Paige, 2 were endangered, 4 were vulnerable, 8 were near threatened, 2 were least concern, and 1 was data deficient at a global scale. For all these species, the main threat was fishing. Sharks are most susceptible to fishing pressure due to cumulative anthropogenic factors such as habitat destruction, climate change, and pollution (Ward-Paige et al., 2010). The absence of sharks has become more known and it can be linked to overfishing. Sharks can even be affected by the perception of them. Shark control programs tried to reduce the number of dangerous sharks near popular beaches. These programs resulted in a higher death rate of sharks and many other species. Shark-control programs have also been a source on unreliable information. However, in more recent times the perception of sharks has changed to a more positive one. Further research on the human dimensions of sharks, the industries that exploit them, and the communities that depend on them are extremely critical for success of conservation (Simpfendorfer et al., 2011).

As one can see, whale sharks as well as many other species are affected by humans. Humans cause global warming and ocean acidification that can be a detriment to this species. Their population declined when overfishing and hunting was present. In more present times, the human interaction has gotten better but the ecotourism approach is not as great as it seemed to be because the whale sharks are still negatively affected.

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