We need sharks, because without sharks the sea dies and without the sea we all die.
The sea is the life support system of our earth, we need a healthy sea:
- The sea supplies more than half of all oxygen in the atmosphere. Phytoplankton (plant plankton) is the main producer. These innumerable microorganisms have the ability to do photosynthesis. During photosynthesis, phytoplankton extracts carbon dioxide from the seawater and releases oxygen. For this purpose, they split mineral salts contained in the sea and the carbon in sunlight into organic matter and oxygen. (Source: Federal Ministry of Education and Research – 2010)
- The sea also regulates the climate and is a pump that allows us fresh water. Together with the sun, the ocean is the driving force of the global cycle, transporting water from land to sea, into the atmosphere and back into the countryside. In addition, our demand for water is constantly increasing, so desalinated seawater is valuable to humans and animals.
- The sea provides humans and animals a source of vital food proteins. Billions of people are therefore dependent on the sea. These include restaurants, sushi bars and fish markets, but also people whose survival depends directly on whether they catch fish.
The important role of sharks
The sea is a huge ecosystem of different oceans connected by ocean currents. Sharks play an important role in this ecosystem. They are at the top of the food pyramid and regulate the populations of fish and other marine animals. The natural balance of stocks is important so that the fragile ecosystem in the sea does not tip over.
A healthy coral reef needs sharks, so that smaller predators do not multiply too much. They eat too many other herbivorous reef inhabitants like parrot fish, which in turn means that young corals are no longer protected from being overgrown by algae. Even mussels and microorganisms that cleanse the sea and keep the water quality in balance, rely on sharks to keep their predators in check.
Scientific studies prove the effects of a diminished shark population:
- In areas with over-fished sharks there is less biodiversity, less fish, and unhealthy seagrass meadows, compared to similar regions where there is a sufficient shark population.
(Source: Stevenson C. – Stanford University – 2006)
- In North Carolina, over-fishing of the sharks led to the complete collapse of the mussel fishery. The cownose rays multiplied uncontrollably without enemies, and extinguished the mussel stocks.
(Source: Ransom A. Myers – Dalhousie University – 2007)
What if there were no sharks (refer the extinction of sharks)?