By: Natalie Cooke, News Writer
Human activity has threatened extinction for sharks and rays, according to a study published by a team of SFU researchers. The study found that 59% of sharks and rays associated with coral reefs, may be facing extinction.
Earth.com reported, “This is due to the fact that coral reefs — which harbor over a quarter of all marine animals and plants — are seriously menaced by a variety of human-related threats, including overfishing, pollution, and climate change.”
The study found fishing has the biggest effect on the shark and ray populations. Sharks cannot reproduce as fast as humans are killing them: this makes them an extremely vulnerable species for extinction.
Sharks and rays are hunted by humans to use in a variety of products. They are commonly used for human consumption, creation of clothing and accessories, and traded internationally for their fins, skins, and meat. They are also used for aquarium display, food for animals, and in medicines.
The SFU researchers emphasized the importance of reducing the amount of shark fishing. To help the shark population recovery, the researchers suggested fishing undertaken by individual fishing households, and industrial fisheries need to be controlled and the management systems need to improve.
The researchers also explained climate change is a threat to coral reefs and their inhabitants, but it is not the most impactful threat when compared to issues such as overfishing.
However, the percentage of CO2 in the atmosphere has increased due to human activity and is impacting the underwater ecosystems. The National Oceanic and Atmospheric Administration explained, “Because of human-driven increased levels of carbon dioxide in the atmosphere, there is more CO2 dissolving into the ocean. The ocean’s average pH is now around 8.1 [ . . . ] as the ocean continues to absorb more CO2, the pH decreases and the ocean becomes more acidic.” When pH levels get too high, organisms cannot build and maintain their skeletons, shells, and other bodily structures.
Ironically, sharks can help make oceans more resilient to climate change. Some shark species can prevent overgrazing from other marine life which allows seagrass to be stronger and denser. This is important as seagrass catches CO2 from the air, preventing ocean water from becoming overly acidic. There are many ways in which sharks and rays can benefit the ecosystem, which is why their extinction would also threaten our changing climate.
To learn more about the study, visit the research article published on Nature Communications’ website.
