| Would the world be better off without sharks? |
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The apex predator is the lead actor in any habitat’s story. The apex predator governs the balance of all species below it. They keep other species of fish in check, ensuring that certain species do not grow uncontrollably. They also play a critical role in the evolution of other species.
Photo: Rob Stewart In the Myers study, an analysis of 17 fishery surveys on the east coast of the United States between 1970 and 2005, with the addition of computer modeling, indicated that the populations of scalloped hammerhead sharks, tiger sharks, bull sharks, dusky sharks and smooth hammerhead sharks may have declined by as much as 97-99%. The decline was largely driven by the dramatic increase in demand for shark fins, as described elsewhere on this site. Without the sharks, former prey have flourished, including rays, skates and small sharks. The cownose ray was especially fruitful, growing tenfold in population. "There may now be over 40 million rays in the population," the researchers say, “which is remarkable for a species with such a low reproductive rate”. And, they love mollusks. This population now consumes 840,000 tons of mollusks each year, several times that of the entire fishery for that part of the mid-Atlantic states. There is increasing alarm around how the loss of sharks may affect the oceans as the great lungs of the earth. Phytoplankton are the micro-plants of the ocean that collectively represent the biggest quantity of vegetation on the planet. Phytoplankton consume more carbon dioxide than all the trees in our forests and produce most of the oxygen we breathe. And, they are food for lots of different species of fish. And many of those fish are, in turn, shark food. Will phytoplankton go the way of North Carolina’s scallops? Sources:
Research Shows Overfishing of Sharks Key Factor in Coral Reef Decline Comments (1)
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