Are bugs really disappearing?

“Arthropods, a group that includes insects, spiders, and crustaceans, make up roughly half of all animals on Earth, by biomass. There are, for example, an estimated 20 quadrillion ants. And because insects are superabundant and everywhere — in streams and lakes, deserts and mountaintops — they are essential parts to every ecosystem.
Scientists estimate that about 90 percent of flowering plants are pollinated by animals, most of which are insects. More than a third of our food crops depend on pollinators, including almonds, chocolate, and coffee.

Insects also make up a huge part of the diet of many animals. Nearly all terrestrial birds in North America feed their young invertebrates. “If you like birds, you should thank an insect,” Black said.

Many fish eat insects, too, including salmon, he said. “They would not make it to the ocean without feeding on insects,” Black said. “This goes all the way up the food chain. Think of grizzly bears. They eat salmon, which rely on insects. And their other main food source is berries, which are insect-pollinated. So bears almost exclusively eat a diet that comes from insects.”

Also worth mentioning: Insects, like dung beetles, clean up animal feces that might otherwise smother the ground and fill the air with a foul stench.”

https://www.vox.com/explain-it-to-me/371434/insect-apocalypse-bees-decline-loss

It’s even hot underwater

“Hotter surface water can slow upwelling, a phenomenon that brings nutrients from deep in the water like nitrogen and phosphorus compounds toward the surface, feeding the plankton that form the foundation of the food pyramid. Roughly half of the fish in the world are caught in upwelling zones.

Hotter water also holds onto less oxygen, which can suffocate sea life. Earlier this year, thousands of dead menhaden fish washed up on the shores of Texas, due in large part to high water temperatures. The water itself becomes more acidic as it heats up, which can disrupt coral formation. And when the temperature rises too high, coral will expel the symbiotic algae that live in their tissues, turning completely white. This is called coral bleaching. All these effects of hotter water temperatures can then make coral more vulnerable to disease.

Sargassum, a type of algae, has seen massive and growing blooms in the Caribbean Sea and Atlantic Ocean in recent years, but there’s been a record quantity this summer, enough to be seen from the sky, washing up on beaches from South America to Florida. As it rots, it emits smelly, toxic hydrogen sulfide gas. Higher water temperatures are likely a factor here as well.

It’s not clear yet exactly how the alarmingly hot waters of the Caribbean will affect seafood catches, but scientists warn that extreme marine heat has proven devastating to fisheries in the past.”

America’s Fishing Industry Is Getting Caught Up in the Trade War

“Tariffs on seafood have hit Alaska in particular, Alaska’s fishing industry generates over $5 billion dollars in economic activity and creates nearly 70,000 jobs in the state, making it a vital lifeline for the state. Over 40 percent of U.S.-caught Alaskan salmon and one-third of all seafood from Alaska is exported to China each year. Much of it is processed in China and then re-imported to the United States for sale in grocery stores.

As the National Fisheries Institute points out, this split processing stream has contributed to rising seafood costs for U.S. consumers, as China’s retaliatory tariffs hit seafood when imported for processing and the original U.S. tariffs hit products upon their return to American shores.”

“For consumers, meanwhile, these costs are discouraging consumption of fish, according to a February study published by data analytics firms IRI and 210 Analytics. That month alone, sales of frozen seafood products decreased by 9.4 percent, while fresh seafood sales decreased by 12 percent.”

What’s killing the world’s biggest fish?

“The largest fish on Earth is a shark. Capable of reaching a length of up to 60 feet — roughly the height of a four-story building — whale sharks, named for their size, are so large that they make great whites look like minnows.

But even giants can disappear. Over the last several decades, more than half of all whale sharks have vanished from the ocean. Some populations have fallen by more than 60 percent.”

“A study in the journal Proceedings of the National Academy of Sciences reveals that cargo ships are likely a leading cause of whale shark deaths. Often, where you find high densities of these endangered fish, you also find shipping traffic, the authors found, and ships are already known to strike and kill these animals.”

“Whale sharks are not the only roadkill. Vast cargo vessels harm many species of marine giants, such as the endangered North Atlantic right whales, and some smaller creatures, like sea turtles. Ships also emit loud noises that disrupt marine life and spew planet-warming carbon dioxide into the atmosphere.

“Shipping is a serious problem for giants of the sea,” said Robert Harcourt, a marine ecologist at Macquarie University in Australia who was not affiliated with the study. “We have an economy that’s derived from moving things around the world in a way that’s not taking into account the cost to the environment.””

“A good step toward decreasing collisions is figuring out where animals are most at risk, and that’s where this new whale shark study comes in. Large ships are required to report their locations, and the authors compared those points to the movement of hundreds of whale sharks, which they had previously tagged with satellite trackers. (This is no easy feat: “You’ve gotta have some nice long fins, a good pair of lungs, and sprint after it underwater,” said David Sims, a marine ecologist at the University of Southampton and a study co-author.)

The results revealed just how vulnerable these fish are: More than 90 percent of the ocean’s surface area that whale sharks use overlaps with the routes of tankers, passenger ships, and fishing vessels. Whale sharks tend to congregate near the coast, where shipping is especially busy”

“many of the sharks’ tracking devices stopped working when the animals entered busy shipping lanes, perhaps because they were killed by ships. (Some trackers even showed sharks swimming into dense shipping routes and then sinking slowly to the seafloor — “the smoking gun for a lethal ship strike,” as Womersley and Sims wrote in The Conversation.)”

“Making oceans safer for marine giants is conceptually simple, and one option is to route ships away from animal hot spots.”

“Even just slowing ships down can make a huge difference. The chance that a cargo ship will kill a whale falls to below 50 percent when it’s moving at around half speed (10 knots, or 11.5 miles per hour), compared to nearly 100 percent when it’s moving more quickly, according to one 2006 study.”

“there’s a big drawback to ships slowing down or going on a different route: It takes longer to deliver goods. That’s one reason studies like this don’t always translate into shipping restrictions. That drawback also makes alternative approaches, such as designing quieter ships or adding wildlife deterrents or propeller guards, appealing (although the benefits of these technologies aren’t well established).”

Climate scientists should pay more attention to fish poop. Really.

“The story goes something like this: Tiny marine organisms called phytoplankton absorb carbon from the water and air around them. As the plankton are eaten by increasingly larger creatures, the carbon then travels up the food chain and into fish. Those fish then release a lot of it back into the ocean through their poop, much of which sinks to the seafloor and can store away carbon for centuries. The scientific term for carbon storage is sequestration.

“We think this is one of the most effective carbon-sequestration mechanisms in the ocean,” Bianchi told Vox. “It reaches the deep layers, where carbon is sequestered for hundreds or thousands of years.”

Carbon that’s stored in the deep sea is carbon that’s not making the oceans more acidic or trapping heat in the atmosphere. In other words, fish poop could be a bulwark against climate change.

The problem is that commercial fishing has sliced the global fish population to a fraction of its former level. As scientists figure out the importance of fish poop, they’re also recognizing a new danger of large-scale fishing. Beyond putting ecosystems at risk, the industry is messing with big nutrient cycles — and perhaps eating into an important carbon sink.”

What Netflix’s Seaspiracy gets wrong about fishing, explained by a marine biologist

“The film includes all the damning evidence and dramatic footage required to make the important point that industrial fishing is — throughout the world — a too often out-of-control, sometimes criminal enterprise that needs to be reined in and regulated. In this, it reinforces and shares with a wide audience a knowledge that is widespread in the ocean conservation community, but not in the public at large.

However, overall Seaspiracy does more harm than good. It takes the very serious issue of the devastating impact of industrial fisheries on life in the ocean and then undermines it with an avalanche of falsehoods. It also employs questionable interviewing techniques, uses anti-Asian tropes, and blames the ocean conservation community, i.e., the very NGOs trying to fix things, rather than the industrial companies actually causing the problem.

Most importantly, it twists the narrative about ocean destruction to support the idea that we — the Netflix subscribers of the world — can save ocean biodiversity by turning vegan. In doing so, Seaspiracy undermines its tremendous potential value: to persuade people to work together, and push for change in policy and rules that will rein in an industry which often breaks the law with impunity.”