The gloomy future of the ocean (part 2)

Heat rise

An increase in CO ₂ means that corals will have to struggle with rising temperatures . Depending on the species and habitat of corals, temperatures higher than the highest temperatures in the summer range of 1-2 ^o C for 3 or 4 weeks will turn a row of rocks into white statues. This bleaching comes from a broken relationship between warm water, soft-bodied coral and colorful endogenous algae called zooxanthellae . They are responsible for photosynthesis and coral rulers benefit in part. Sometimes the parties reunite after being separated by bleaching, but the long-term shortage of zooxanthellae will kill shallow-water corals.

The work of zooxanthellae in the last decade has revealed special properties in the heat resistance of algae. According to Ray Berkelmans, Townsville Institute of Marine Science in Australia, the coral reefs are predominantly heat resistant by a D-line variant than other strains. Scientists including Andrew Baker, University of Miami, Florida are trying to save coral reefs by replacing the weak zooxanthellae with better heat-resistant species.

This strategy does not make Hoegh-Guldberg more optimistic about the future of corals if carbon emissions continue to rise. Heat waves have bleached coral in large areas in recent years, but Hoegh-Guldberg has witnessed natural adaptation of zooxanthellae algae. 'People will have enough time to witness the magical adaptation of the coral.'

The coral adaptation prospect didn't make Hoegh-Guldbergh even more happy. Atmospheric carbon dioxide has ever peaked and ocean pH has increased in the history of the earth. So the question is whether corals survive if they only apply previous adaptive tactics.

'This is ridiculous. Ancient corals have more time to get used to hot environments and lower pH today. ' He illustrated with data from research in Science. He and his colleagues used published data on ancient ice-bubble air to calculate changes in atmospheric CO ₂ density. This density has increased 1,000 times over every century during the industrial revolution compared to 420,000 years ago.

In addition, Hoegh-Guldberg said he could hardly believe that calcified organisms actually found a way to survive the previous greenhouse gas outbreaks. During the early Triassic period, CO ₂ density reached 5 times higher than today. Hoegh-Guldberg noticed the absence of fossil evidence in both reef coral and algae.

Some corals are so ancient today that they survived through hot environments and oceanic chemical composition. These species probably existed without the need for a calcified skeleton.'They really became anemones.'

Even if all corals become successful, naked bodied species, the species that live in the reef will have no place to live. Complex fissures and cliffs in reefs are home to most ocean biodiversity, perhaps millions of species. If there are no complex habitats on reefs created by corals, the ocean will become much simpler.

Floating microorganisms

Baby with a corn grain, winged limacina helicina is the favorite food of larger creatures.The pH of reduced seawater may interfere with the process of forming its outer shell.(Photo: Hofmann)

Smaller than coral, some simple life floating in seawater like plankton also needs calcium carbonate to grow.

The microorganism coccolithophores , has become a symbol in the study of ocean pH change thanks to Ulf Riebesell of the Leibniz Marine Science Institute in Kiel, Germany. This creature-like species looks like countless wheel covers that are welded around a giant beach game ball. These splendid round caps have platelets made of calcium carbonate, which acts as a type of photosynthetic cell.

The species of coccolithophores blooming in spring like Emiliania huxleyi can stretch an area the size of Ireland. The light reflects all the platelets that make up the cloudy, blue veins on the ocean surface that can be observed from the universe.

Emiliania huxleyi has a way of forming oxidative structures unlike corals. However, coccolithophores cannot grow normally as in low pH seawater. In such experiments that simulated water environments, he witnessed stunted cells and platelets weakened or destroyed.

Growth defects are occurring in other 'undersea builders' , such as shellfish. And of the few larvae studies, Gretchen Hofmann, University of California, Santa Barbara, has presented problems that occur with sea urchins at larval stage. In excess CO2 seawater, sea urchin larvae become 'shorter and bigger.'

Outside the crust

Increasingly acidified seawater can damage Emiliania huxleyi, a shellfish from calcium carbonate platelets, but useful for Trichodesmium, a nitrogen fixing species.(Photo: Björn Rost; David Caron / Univ. Of Southern California)

Much of the first wave of research on the next generation of ocean focuses on the future of calcification. This is not bullshit at all. According to Scott Doney, Woods Hole Oceanographic Institution, organisms that make up 46 percent of America's annual seafood production form a form of calcium structure, such as sea oysters. In addition, species that eat calcium species such as pink salmon fatten themselves with pteropods. The number of these species will increase this percentage.

However, the chemical composition of water also affects the life of non-calcium ocean creatures and researchers are trying to understand these issues. For example, according to the work under study by Brad Seibel, Rhode Island University in Kingston, and colleagues, squid species seem to have difficulty moving in low pH environments. In such a sea environment, oxygen transport in the blood of squid is disordered and they become lethargic and slow.

According to David Hutchins, University of Southern California in Los Angeles, the future of the ocean will be good news for some other species, especially non-calcium species. The nitrogen-fixing cyanobacteria show that they grow stronger in experiments that simulate ocean acidification environments.'They really love CO2'.

Cyanobacteria cells, such as those in the Trichodesmium-like body, do not efficiently transport CO2 from their surroundings to their internal heat-retaining organs. A denser atmosphere will help cells work more efficiently.

Anyone who survives or disappears among the plankton species in the new ocean environment affects larger organisms. Marine animals that live on plankton can enjoy this species and are indifferent to other species. If the number of plankton changes, then those animals will also be changed. This will also affect the highest level predators, even land animals.

Based on future ocean simulation experiments, Hutchins calculates that the evolution of plankton means that more species will appear to hunt bacteria and less fish.

'It will be a world we don't like.'