The Science of Sharks

TheScience of Sharks

‘Oceans’is a 2009 Franco-American nature documentary film that seeks toexplore the marine life in earth’s five oceans. The movie presentsfactual evidence concerning the oceanic journey. It shows anexquisite world that is filled with different types of fish. Thedifferent colors of the fish blend well with the blue color of waterthus crowning the beauty. Amid such beauty and glamor, one wouldexpect peace to prevail. However, the North American version of themovie shows violent massacres of the animals. A hungry mob ofdolphins, whaler sharks and whales hunts and feasts on sardines. Somesea lions are consumed by the killer whale and the white shark. Atthe deep ends of the sea, some blue whale feast mercilessly on krill.The brutality does not end there. Outside the ocean, some babyturtles are not spared by the frigate birds. On the other hand, thecoral reef is peaceful and creatures are minding their own business.Some of the peaceful creatures such as the sheep head wrass are busymating. The migrating dolphins, sharks and whales, create beautifulcurrents that trace their paths.

Althoughthe movie showed numerous kinds of fish, I was very interested in thesharks’ behavior. The boneless fish are carnivores in nature, andthey are known for wreaking havoc in the deep blue oceans. They canmigrate for long distances at great speeds. Therefore, I wanted tofind out the relationship between their feeding habits and the longline fishing activities of man. My desire was to understand moreabout the sharks’ behavior as well as confirming whether the moviewas conveying the right information. Conduction more research wouldhelp to quench my thirst for knowledge. I conducted an in-depthsearch by using the internet and gathered a lot of information. Thisarticle is a comprehensive report of my findings.

Schindler,Essington, and Kitchell conducted a study that sought to define theimpact of pelagic fisheries on predators. The study found that theexploitation of species leads to food web consequences. A comparisonwas made between the effects of the exploitation of the fast growingspecies to the slow growing ones. The best example of a fast growingfish is the yellow tuna. Evidently, fisheries that are directedtoward the tunas end up capturing blue sharks in some incidences.Looking at the history of the sharks, the surge in finning had led toa rise in the mortality of fully grown sharks. Simple populationmodels were created in order to account for the changes in the realpopulation sizes in response to fisheries. The aim of the analysiswas to estimate the predator response to the changes in fishingpatterns. The results showed that, the low exploitation ratesaffected the sharks’ population greatly. Although the tuna havehigher predation rates than the blue sharks, long line fisheriesaffect the sharks’ predation than the tuna. Food web responses arestrongest where there are specialized predation and high unexploitedbiomass of long-lived species. Therefore, in order to minimize theoutcomes of longtime fisheries, an active management would help toreduce the mortality in sharks[CITATION Sch02 l 1033 ].

Thereis increased exploitation of sharks by long line fisheries. Thisraises some questions concerning the changes in food webs whereSharks are the apex predators. Kitchell, Essington and Boggs,evaluated the trophic interaction changes resulting from theexploitations of the sharks in the Pacific. The increasedexploitation of the blue sharks results in responses that areadvantageous to billfishes and other shark species. However, theeffects are modest on more food web components. Modest food chains,where adult sharks feed on the juvenile sharks indicate nonlinearreactions in the shark populations. The analysis of the Pacificrevealed that sharks are not the major predators. However, theincreased long line fisheries can affect the food webs that supportthe sharks’ survival[ CITATION Kit02 l 1033 ].

Thereare different kinds of sharks that are equally dangerous andunpredictable. They exhibit unique behaviors that tend to be hard tostudy. This is because they are difficult to capture and maintain.Therefore, observing their behaviors tends to be an uphill task[ CITATION Gru77 l 1033 ].It would be necessary to find some approaches that can fasten theprogress in knowing and understanding these creatures. Investigationsconcerning the sharks’ behavior require the use of methodologicalframeworks of ethology and comparative psychology.

Gruberand Myberg presented some six approaches for finding out thebehaviors of the sharks. The first approach would be to carry out anintuitive study of the natural history and fisheries statistics. Thesecond approach would be to make inferences about the sharks’behavior drawn from taxonomic and morphologic considerations. The“structure of behavior” is the third approach. It refers todirect observations of behavior. The approach incorporates someexamples of field and laboratory examinations with the sharks. Thedirect observations increase the accuracy. Studying the sharks’activity rhythms is the fourth approach. The approach gives shortterm results and fails to give much information concerning thelong-term activities. The fifth approach focuses more on thepsychological studies of learning revealed that learning is prevalentin a shark’s life. The creatures are not stupid. They can learn newthings, especially on habituation. Using the sixth approach, studyingthe sensory physiology revealed that sharks can quickly sense anyslight changes in the environmental stimuli. Scientists can easilyovercome the difficulties in understanding such behavior by using thesix approaches[ CITATION Gru77 l 1033 ].


Thecaptivating movie gave me a glimpse of the glamor in the oceans. Ilearned a lot about the behaviors of fishes in the sea. My researchhas revealed the difficulties involved in studying the behaviors ofthese animals. The study approach used in the movie entailed directobservations. The facts presented in the film are, therefore,accurate and concise. Advancement in technology has made the studiessimpler. On a sad note, an in-depth research revealed results ofman’s greed. Sharks are an endangered species. Long line fishing ishaving a greater impact on the sharks’ population. The effect istwo sided. Firstly, Sharks are hunted by man for their fins, and, onthe other hand, long line fishing reduces the small fish populationin the oceans leading to starvation for the sharks. Human activitiesare the number one threat to the survival of the shark population.Certainly, sharks adorn the oceans. In order to balance the food webin the seas and oceans, these creatures should be protected.


Gruber, Samwel H and Arthur A Myberg. &quotApporoaches to the Study of the Behavior of Sharks.&quot American Zoologist (1977): 471-476.

Kitchell, Jmaes F, et al. &quotThe Role of Sharks and Longline Fisheries in a Pelagic Ecosystem of the Central Pacific. .&quot Ecosystems (2002): 202-210.

Schindler, Daniel E, et al. &quotSharks and Tunas: Fisheries Impacts on Predators with Contrasting Life Histories.&quot Ecological Applications (2002): 735-748.