by Cesar Barrio Amorós
A healthy natural system is expected to possess five “consumer” categories. For example, in the ocean the first stage of the food pyramid is the phytoplankton, a microscopic algae, which is eaten by zooplankton, tiny microscopic animals either in their larval, juvenile or adult stages, which are then consumed by shellfish, corals, mollusks, and small filtering fish. Above them are carnivores, basically predators and cetaceans.
At the very top of the pyramid are the super predators, basically sharks and orcas. Currently, global overfishing is mainly affecting predators (tuna and other fish that we eat every day, marlin, mahi mahi, swordfish, snapper, sea bass) and filtering fish, such as crustaceans and shrimp. The most affected are the top predators, specifically sharks which are responsible for keeping the system clean and healthy.
They feed on sick animals and carrion, and also accumulate all toxins of the food pyramid, especially mercury. Apart from this, sharks cannot excrete urea as mammals, by urinating. Their “urine” is eliminated through the blood, so there is a high amount of uric acid in their flesh. Basically, shark meat is toxic!
In Costa Rica “ceviche” and even shark steaks (bolillo in Spanish) are very popular. Bolillo is the denomination applied to several species of sharks that are caught without regard, trapped in gillnets and longlines. Very affected is the endangered hammerhead shark, which comes to Costa Rica’s Pacific coast for breeding. Costa Rica with principles based on ecology, should be the first in the world in categorically prohibiting shark fishing of any kind, and thereby setting an example for the rest of the planet.
Without sharks, there will be no healthy fish or oceans for future generations.