Why care about sharks?
Updated: Apr 3
The word “shark” can strike fear into the hearts of many people. Our primal terror of large predators means we often associate these animals with threat or horror. However, in reality, there are very few species of sharks which actually pose a threat to human beings and even these ‘dangerous’ animals are critical for the health of our planet.
We are now more aware than ever that our environment is threatened by human activity; climate change, plastic pollution, ocean acidification; we hear these terms in the news and on social media regularly. So, with the looming threat of melting polar icecaps, global desertification and extreme weather events, you might ask yourself why the plight of sharks should be a priority?
Are sharks even threatened by human activity? And why would this even affect your life?
In short… why should you care?
You should care, for several reasons. Let’s see if we can find one that applies to you:
The Health of the Environment
Sharks are predators, meaning they gain their nutrition from consuming other animals. Some sharks are “mesopredators”, some are “apex predators”, so they often occupy a high level in a trophic food web and exert “top-down” control of the ecosystem. The eradication of sharks and subsequent removal of this top-down control impacts upon every species beneath sharks in lower trophic levels. This can not only impact each species individually, but also affect the dynamics of the entire community; shifting nutrient cycling and even altering the physical “abiotic” environment. The removal of the apex predator shark, means the species which these animals normally consume (mesopredators) experience release from predation pressure and the population can explode. This means more mesopredators hunting “herbivores”, which means their populations decrease. With less herbivores grazing,“producers” such as algae can flourish, which can form blooms that smother coral reefs. You might not think the shark at the top has anything to do with the plants at the bottom, but every species within a community is interconnected with every other in a delicately balanced web of interactions. To keep our marine ecosystems healthy it is critical that healthy populations of every different type of species is maintained, including sharks (Ferretti et al., 2010).
Our Leisure Activities
Many people use the ocean environment for leisure activities during their free time. For example, some enjoy a spot of fishing. Some fish for relaxation; enjoying time out in the fresh air and enjoying nature, others fish for sport, in competitions. Many people also enjoy scuba diving or snorkelling to see corals, fish and (maybe) sharks, either on a regular basis or as an exciting treat during a tropical holiday. In fact, there are booming tourism industries exploiting the ocean environment in more countries than I can mention. If shark populations collapsed, these activities will no longer be on the schedule at the weekend or on your next holiday. I know that is something I would certainly miss.
The Global Economy
The aforementioned booming tourism industry is also critical to the economy of many nations; the industry creates localised and national capitol, and creates millions of jobs globally, supporting communities. This is not just limited to tropical climes, but is very important to the economies of many western nations, including the UK. Whale watching, shark watching, dolphin watching expeditions are big business in many British coastal communities and are important to the country’s economy as a whole. It is not just ticket sales that these companies affect, but there are numerous jobs in the local community that are created surrounding successful tourism; hotels, restaurants, local shops. If ocean ecosystems are permanently damaged and these industries collapse, it could have a huge affect on individuals and communities up and down the country (Cisneros-Montemayor et al., 2013).
Human Food Sources
Many people are not interested in environmental concerns, as these issues seem to be detached from their lives and, therefore, irrelevant. However, the survival of sharks may be more relevant to your daily life than you ever realised. As we have already discussed, top-down control can be critical in maintaining healthy populations of mid-trophic level species. Many of these species are, in fact, our seafoods. If a trophic cascade caused the localised collapse of fish stocks, this could have a huge impact upon our future diets. If fisheries did collapse and were forced to close, not only may you not be able to enjoy certain seafoods, but this could have an enormous impact upon countries which rely upon seafood at a substance level. Many communities of the coastal countries in Africa and Asia rely on fishing for their food and the Food and Agriculture Organisation estimates that an excess of 1 billion people globally rely on seafood as their major source of protein. If we do not manage shark populations successfully, it is possible we could see localised famines in the future (FAO, 2000).
Human beings as a species are generally consumerist; we exploit natural resources and engineer our environment for our own comfort and prosperity, but many would argue that we are animals like any other and we have no more right to this world that any other species. It could be argued that human beings are responsible for the snowballing extinctions currently occurring and that we therefore have a moral responsibility to do everything we can to protect the populations that we are damaging.
Because we are damaging shark populations, globally, at an alarming rate.
Cisneros-Montemayor, A., Barnes-Mauthe, M., Al-Abdulrazzak, D., Navarro-Holm, E. and Sumaila, U. (2013). Global economic value of shark ecotourism: implications for conservation. Oryx, 47:03, 381-388. Access online.
FAO (2000). The State of World Fisheries and Aquaculture. FAO, Rome, Italy. Access online.
Ferretti F., Worm B., Britten G.L., Heithaus M.R & Lotze H.K. (2010). Patterns and ecosystem consequences of shark declines in the ocean. Ecology Letters, 13, 1055-1071, doi: 10.1111/j.1461-0248.2010.01489.x. Access online.