Shipping poses a ‘significant threat’ to endangered species of whale sharks, marine biologists have earlier warned. They have discovered that ships end up killing significant numbers of sharks, the biggest fish species alive on the planet today. All over the world, their numbers have started declining in recent years but experts have been bemused as to what could be the reason.
Scientists from the Marine Biological Association (MBA) and the University of Southampton have conducted path-breaking research that justifies lethal collisions of whale sharks with large vessels are largely underestimated and maybe the reason why the populations are reducing.
It has previously been suggested that as whale sharks spend a lot of time in coastal regions and surface waters, a significant number of deaths could have been brought about by collisions with large ships. However, there was no effective way of monitoring the threat till now.
Scientists from about 50 international universities and research institutions have tracked the movements of ships and whale sharks all over the globe to recognize the areas of potential collisions and risks.
The team has mapped some areas as shark ‘hotspots’ that overlapped with global fleets of fishing, cargo, and passenger’s vessels as well as tankers to reveal that more than 90% of whale shark movements had fallen under the footprint of shipping activities.
The study reflected that whale shark tag transmissions had been ending more frequently in busy shipping channels than what is likely, even when they ruled out technical glitches. The team concluded that the loss of transmissions was possible because whale sharks get struck, killed, and eventually sink onto the ocean floor.
A PhD Researcher named Freya Womersley from the University of Southampton spearheaded the study for the Global Shark Movement Project. She mentioned that the maritime shipping industry allows sourcing a variety of products globally, which may be resulting in the decline of whale sharks, a hugely important species living in the oceans.
Satellite tracked movement data from nearly 350 whale sharks was also submitted into the Global Shark Movement Project, led by researchers from the Marine Biological Association (MBA).
Whale sharks are slow-moving giants of t that feed on microscopic animals known as zooplankton. They generally grow to be larger than a double-decker bus: between 20 to 52 feet but maybe up to 65 feet long. Whale sharks help regulate the ocean’s plankton levels and play a vital role in the healthy ocean ecosystems and marine food web.
Professor David Sims, a senior research fellow and the founder of the Global Shark Movement Project mentioned that some of the tags that record depth and the location reflected whale sharks sliding into the shipping channels and then, slowly sinking to the seafloor almost several hundreds metres below. This is the “smoking gun” of a lethal ship strike.
Currently, there is no international regulation to protect whale sharks against vessel collisions. The research team warns that the species faces an uncertain future if actions are not taken immediately. They hope the findings they’ve furnished inform management decisions and protect whale sharks from more population declines in the near future.