Whales are some of the most fascinating creatures roaming the world’s oceans. They play an integral role in the overall health of the marine environment. Previous studies revealed that each great whale sequesters an estimated 33 tons of CO2 on average, thus playing their part in the fight against climate change. Unfortunately, they are also some of the most vulnerable animals.
Reports show that 6 out of the 13 great whale species are classified as endangered or vulnerable, even after decades of protection. This unfortunate truth is primarily due to habitat loss, global warming, and climate change. As our oceans continue to warm, whale populations are finding it extremely hard to adapt. Rises in sea levels, acidification, freshening of seawater, changes in sea temperature, the decline of food sources, and the loss of icy polar habitats are just some of the many dangers which climate change poses for these giant mammals.
According to One Green Planet, an online guide to making conscious choices that help people, animals and the planet, whaling practices went into overdrive at the turn of the last century due to a rapid increase in demand for whale meat in many countries. An estimated 1,339,232 whales were killed by commercial whaling fleets in the Antarctic alone 1904 to 1987. This is equivalent to 16,000 whales being murdered every year for 83 consecutive years. While hunting for blue whales was banned in 1964, their numbers remain critically low because, by the time the ban was implemented, the population had dropped significantly.
Last year’s reports revealed that blue whales still struggle to repopulate with only around 2,000 of them. Worldwide numbers of these marine mammals have reduced from 220,000 to as little as 3,000. Other species of whales have also been suffering. For instance, north Atlantic right whales are considered one of the most endangered species with little sign of recovery in most areas. In the east, sightings are extremely rare.
Impacts of Climate Change on Whales
Multiple studies have shown that climate change is expected to be the main reason for mass extinctions in the 21st century, and whales will be among the most vulnerable species. The rapid warming of the planet is leading to a loss of habitat for whales and greater competition for a diminishing amount of prey species. Climate change has been affecting the timing and ranges of their migration, their distribution and even their ability to reproduce.
A 2015 study documented how whales have adapted to increasing sea surface temperature for the past decades. According to Phys.org, an internet news portal that provides the latest news on science, the researchers studied fin and humpback whales, which have existed for millions of years, to learn how they have adapted to past climate changes and have been successful in evolutionary terms. "To our knowledge, this is the first study showing how such long-lived species adapt to climate change,” Dr. Christian Ramp, a lead author of the study, said.
The findings of the study published in the scientific journal PLoS ONE found put that whales arrived at feeding grounds on average one day earlier each year, suggesting that they changed the timing of their seasonal migration in response to global warming. The team was surprised to discover that the two species synchronized their arrival times each year to avoid competing with each other for food, despite following separate migration routes. They studied 450 fin whales and 270 humpbacks for 27 years.
"Whether this pattern can continue as ocean temperatures increase is an open question, and the implications for these two species in the region are uncertain but could be profound. The continuing rise in ocean temperatures could eventually cause problems for long-distance migrating humpback whales to time their arrival in the feeding grounds with the occurrence of their main prey,” Ramp said.
Whales Face More Fatal Ship Collisions
Whales are facing multiple threats from habitat loss and fishing to warming waters. Now, scientists have identified another threat to their populations: ship strikes. Scientists recently found out that warming waters are causing the right whales and some other species to stray outside protected zones designed to keep them safe from ships.
“When one of their main food resources goes away, it means they start exploring new areas for food. And that means they’re encountering all new sources of mortality because they are going into these places where they are not protected,” Nick Record, a senior research scientist at Bigelow Laboratory for Ocean Sciences in East Boothbay, Maine, said.
Recent reports showed that at least three right whales died from ship strikes last year, which have been documented in the Gulf of Saint Lawrence off Canada. Scientists reported that the risk of such accidents has been increasing since the start of the 20th century. There’s also an increased ship strike involving rare North Atlantic right whales on the East Coast and giant blue whales on the West Coast, while the number of strikes off California increased threefold in 2018.
The death toll among whale species is driving them closer to extinction. According to Time, an American weekly news magazine and news website published based in New York City, one of the most frequent causes of accidental death in large whales is vessel strikes. Many advocates and scientists have encouraged the International Maritime Organization to step up to protect the whales. However, this will be hard to do without cooperation from the worldwide shipping industry.
Scientists have also debated whether or not enforcing slower speeds for large ships will be a great solution. Some companies in the shipping industry have expressed their willingness to help. For instance, the World Shipping Council expressed a willingness to keep working to keep shipping activity away from whales. However, they are skeptical about whether slowing vessels would help. “Reduced ship speeds also increase the residence time of a ship in a given area where whales are active. Given those factors, there is some notable uncertainty about how effective reducing ship speeds is in lowering the risk of whale strikes,” they said.
Recently, the Center for Biological Diversity sent a notice letter that threatened a lawsuit against the National Marine Fisheries Service and the US Coast Guard if officials continue ignoring the requirements of the Endangered Species Act in agency consultations, studies, and actions, which includes speed limits in shipping lanes or protecting critical habitat areas. “Ship strikes kill far too many endangered whales off California’s coast, and the Trump administration can’t keep ignoring a deadly threat that’s only getting worse,” Brian Segee, an attorney at the Center, said.