Why do dead whales continue to be washed away in San Francisco?
A series of recent deaths in the area has raised concerns, but scientists say it may not be a sign of a catastrophe on April 8 at Muir Beach near San Francisco for adult females. Gray whale is dead. Photo: The Marine Mammal Center / Reuters A 45-foot corpse angered the waves at Fort Funston Beach, just south of San Francisco, attracting a small crowd of hikers and hang gliders. The stench remained in the evening breeze as the seabirds circled the young fin whale animals. The whale was the fifth whale to be washed ashore in the area this month. The other four were gray whales. Giant whales travel 11,000 miles each year from Alaska to Baja and vice versa. All of these were found on the beach near the city in just eight days. Each was an amazing scene, raising immediate concerns for many observers. Whales are an important part of the ecosystem and are often regarded as markers of marine health, and whale death can serve as an indicator of something wrong. But scientists say the situation is more complicated. Investigations into the death of whales are ongoing, and experts say that so far no smoke-breathing guns have been used. Some marine researchers believe that death can be more cyclical than the signs of a catastrophe. “At first glance, it sounds scary,” says Joshua Stewart, a researcher at the National Oceanic and Atmospheric Administration (Noaa). “But this is not an isolated event, and I feel relieved to some extent.” After the endangered species in the 1950s, gray whales made a remarkable recovery and were removed from the endangered species list in 1994. It has recovered to the level that allows it. North in early spring. They are also one of the most studied marine mammals, with data dating back to the 1960s. Every time a whale lands, scientists have a new opportunity to learn about ocean conditions. However, the West Coast gray whale population has declined in recent years, down about 24% from 2016. According to Noaa’s data, there are currently an estimated 20,580 whales remaining. And this month’s mass deaths weren’t the first. In 2019, Noaa declared an ongoing “abnormal death event” when 122 whales were washed away on the west coast from California to Alaska. This is more than four times the average of 29 for the last 18 years. .. Stewart, who is tracking gray whale populations, says that even if they decline, populations are still close to record highs. “Despite these recessions, which were very painful at the time, they bounced back and forth many times,” he added, adding that they are a highly adaptable and elastic species. It was. “I want to know if this decline is ongoing or temporary.” Gray whales are one of the most studied marine mammals. Photo: Giller Moarias / AFP / Getty Images On April 8th, we investigated two whales in the bay at the same time. One corpse floated for days before anchoring at Berkeley Marina. The other was washed ashore at Muir Beach, just north of San Francisco. A team from the Marine Mammals Center and the California Academy of Sciences performed an autopsy that included tissue sampling, evaluation of internal organs and reproductive tract, and evaluation of ribs and vertebrae for signs of trauma or impact. Moe Flannery, senior collection manager for birds and mammals at the California Academy of Sciences, says he is at the site of the autopsy and the team has not completed the investigation. However, causes can include lack of food and illness. “There is no real answer yet,” she said, adding that despite her death, scientists are hoping for a recovery in gray whale populations. “They are resilient species and I think they are concerned, but this is just a little blip of time and I hope the species themselves will rebound as they did in the past.” Discovered on Friday. Ship strikes have already been identified as the cause of several deaths, including fin whales. Unlike gray whales, fin whales are still listed as endangered. With an estimated 3,200 remaining along the west coast off California, Oregon and Washington, ship strikes are the greatest threat to their survival. “This shows the number of threats these whales face,” says Callie Steffen, project scientist at the Benioff Ocean Initiative. Steffen works for the team that developed the Whale Safe project. This project will use the data to help seafarers map where whales are when planning a voyage off Southern California. “It’s like a smokey bear fire warning, but it’s for whales,” she says, with a positive impact. However, a 2019 study by the Scripps Institution of Oceanography at the University of California, San Diego shows that whales approach the coast and are at increased risk of harm from ship collisions, loud destructive noise from harbors, chemical pollution, and entanglement. There is a possibility. .. The authors of the study believe that this change is related to the whale’s biological clock. Ali Friedrender, a marine ecologist who teaches and leads the lab at the University of California, Santa Cruz, should consider whale death a danger signal, whether or not the whale was killed by malnutrition or a ship strike. It states. Human activity, from shipping to the climate crisis, is causing changes that adversely affect whales, even if the only cause behind the decline cannot be addressed. “That means people are more likely to affect and change these whales’ food-hungry ecosystems,” says Friedlander. “There are so many downstream influences and implications that we do in our daily lives. The actions we take locally can have consequences and implications over a very long period of time. Must be open. “