Whale sharks use oil and gas rigs as pit stops during their migrations, traveling thousands of kilometers across the oceans. These human-made structures attract marine life, providing the sharks with an easy meal of plankton. However, experts are concerned that this lure could put the endangered whale sharks at risk of ship strikes or chemical pollution. Satellite tracking off the coast of western Australia shows how oil and gas platforms influence the movements of these gentle giants, with the sharks using the rigs as stopping points before continuing their migration.
Reaching up to 18 meters in length, whale sharks are the largest fish on the planet and consume around 20 kilograms of plankton daily. Oil and gas rigs act like artificial reefs, attracting plenty of prey for the sharks to feed on. Researchers have tagged and tracked 78 whale sharks over 14 years to study their movements and how geomorphological features influence their routes. While natural features like pinnacles, canyons, and seamounts also act as pit stops for the sharks, the attraction towards oil rigs, possibly due to plankton being drawn to the platforms’ beams of light, could put the filter feeders at risk of ship strikes and pollution from oil spills or discharges.
The authors of the study hope that their findings will help decision-makers managing marine protected areas and raise awareness of the potential impact on marine life when human-made platforms are decommissioned or new structures like offshore wind turbines are built. The increasing development of renewable energy sources will add additional structure to many areas along continental margins, potentially posing a threat to marine life. The concern is particularly relevant as whale sharks are listed as endangered by the International Union for Conservation of Nature, highlighting the importance of understanding and protecting these gentle giants as they navigate the oceans.
The comparison of oil and gas rigs to truck stops on a highway provides an analogy for how whale sharks use these seafloor features as rest stops during their migrations. Like how a family may stop at a truck stop to fuel up and grab a quick bite during a road trip, whale sharks use oil rigs and other underwater structures to feed before continuing their journey. The platforms act as a buffet of prey for the sharks, attracting them with an abundant food source. However, the potential risks of collision with vessels and exposure to pollution highlight the need to consider the impact of human-made structures on marine life.
The study emphasizes the importance of understanding the interactions between marine species and human-made structures to mitigate potential risks to vulnerable species like whale sharks. As offshore development for renewable energy sources increases, awareness of these impacts becomes crucial for conservation efforts. By studying the movements of whale sharks in relation to oil and gas rigs, researchers can provide valuable insights into how these structures influence the behavior and migration patterns of marine animals. Ultimately, this research aims to support informed decision-making in managing marine ecosystems and protecting endangered species in the face of ongoing environmental changes.
