After 6 years, marine life has yet to recover from the ocean’s brutal heat point

Nicknamed the “Blob,” a large slick of abnormally warm water that covered part of the Pacific Ocean from 2014 to 2016 behaved just like a B-grade horror movie, having a devastating effect on a variety of species.

A new study on the Santa Barbara Channel off the California coast sheds light on how this environmental horror show continues to impact marine ecosystems.

The point caused major shifts in the aquatic ecosystems of the time, especially the sessile animals, the ones that stuck in place like anemones. This latest research shows that after six years, the underwater inhabitants that inhabit the kelp forest ecosystem still haven’t gone back to where they used to be.

While levels of sessile invertebrates — filter feeders attached to coral reefs — have generally rebounded, so have numbers belonging to invasive species. Watersipura Supatra (modern access) f Bogula Nritina (Long-time resident) Flourished. These are types of algae. Small, colonial, tentacled animals that essentially work together in groups as a single organism.

“The groups of animals that seemed to be the winners, at least during the warm period, were longer-lived species, such as clams and sea anemones,” says ecologist Christine Michaud, of the University of California, Santa Barbara.

“But after the Blob, the story is a bit different. Bryozoan cover has increased very quickly, and there are a couple of invasive bryozoans that are now more abundant.”

Populations of gentle invertebrates experienced an initial decline of 71 percent over 2015 when the point settled, because warmer water means creatures like anemones, tubeworms and clams run out of phytoplankton to feed on.

Plankton depend on nutrients from cold waters, which were limited by the presence of warm water. The heat also increased the metabolism of these sessile invertebrates, which meant that they needed more food than they were given.

Several reasons can be responsible for dominance W Supatra And the B. neritinaThey include the ability to survive at higher temperatures, the researchers say, and to compete more aggressively for space on corals. In addition, the continued resilience of kelp forests in the region may have helped make room for these algae.

Another native gastropod is known as the scaly vermiform snail (Squamous Thylacodes) was doing well, likely because it is better able to tolerate warmer waters, and because its food source choices go beyond plankton.

The problem with these changes is that the newcomers do not play the same role in the ecosystem as the species they replaced. For example, bryozoans are shorter-lived and grow faster, not as adept at surviving less intense periods of warming but for longer periods as those of the animals they replaced.

“This pattern in community structure persisted throughout the post-point period, suggesting that this may be more of a long-term shift in benthic animal populations,” says Michaud. “These communities may continue to change as we see more marine heat waves and continued warming.”

The waters in the Santa Barbara Channel are often subject to temperature fluctuations, such as those caused by El Niño events. However, unlike the Blob, these events are also accompanied by large wave action and storms – which, for example, rip off the covers of kelp forests.

While corals have been shown to be able to bounce back from these warmer periods, the blue dot has increased temperatures without driving seas into a frenzy. This makes it a very interesting period for researchers to study, not least because ocean temperatures continue to rise due to global warming.

The region has been closely monitored for decades, and such monitoring will continue. Researchers expect the Blob’s continuing effects, including the ways in which it affects marine species higher up the food chain, to continue.

“The Blob is exactly the kind of event that demonstrates why long-term research is so important,” says marine ecologist Bob Miller, of the University of California, Santa Barbara. “If we had to respond to such an event with new research, we would never know what the real effect was.”

Research published in Communication biology.

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