{"id":14611,"date":"2018-03-02T09:15:10","date_gmt":"2018-03-02T09:15:10","guid":{"rendered":"https:\/\/www.revoscience.com\/en\/?p=14611"},"modified":"2020-05-27T06:07:17","modified_gmt":"2020-05-27T06:07:17","slug":"high-salinity-protects-corals-heat-stress","status":"publish","type":"post","link":"https:\/\/www.revoscience.com\/en\/high-salinity-protects-corals-heat-stress\/","title":{"rendered":"High salinity protects corals from heat stress"},"content":{"rendered":"

Corals living in highly saline waters may be more tolerant to rising water temperatures.<\/strong><\/em><\/span><\/p>\n

\"\"
Systematic experiments on a species of sea anemone indicates that increased salinity promotes thermotolerance in the presence of specific symbionts. The findings hold implications for the impact of climate change on coral reefs.
Credit : \u00a9 2018 Hagen M. Gegner<\/figcaption><\/figure>\n

Scientists have long suspected that corals living in very salty water can also tolerate higher water temperatures, but the link has never been verified. Now, KAUST researchers have shown that salinity directly influences the ability of the coral model organism Aiptasia to cope in warmer water and may have identified the compound that helps this process.\u00a0<\/span><\/p>\n

\u201cWe, like others, had observed that corals from highly saline waters like the Red Sea can tolerate high water temperatures, but no one had systematically analyzed this,\u201d says Ph.D. student Hagen Gegner, who worked on the project with supervisors Christian Voolstra and Manuel Aranda and colleagues. \u201cWe conducted heat stress experiments to determine the effects of different salinity levels on two Aiptasia strains and their associated symbionts, strains of the dinoflagellate algae Symbiodinium.\u201d<\/span><\/p>\n

The sea anemone Aiptasia is closely related to reef-building corals, and it is regularly used as a coral model organism because it is easier, cheaper and quicker to grow than corals themselves. The researchers chose two Aiptasia strains, H2 and CC7, each of which hosts a different Symbiodinium strain. When corals and anemones are under heat stress, they respond by expelling their symbionts in a process called bleaching, which can kill corals if stresses persist.\u00a0<\/span><\/p>\n

The team reared Aiptasia anemones at a constant temperature of 25 degrees Celsius before transferring them into low-, medium- and high-salinity tanks. Each tank was then heated to 34 degrees Celsius and maintained at the higher temperature. They measured Symbiodinium levels at the beginning of the experiment and again once bleaching had occurred.\u00a0<\/span><\/p>\n

\u201cFor one of the anemone-symbiont combinations, the severity of bleaching was significantly reduced as salinity increased,\u201d says Gegner. \u201cAlthough both combinations lost Symbiodinium at all salinity levels, more were retained by Aiptasia H2. This also coincided with limited damage to the animal\u2019s photosynthetic efficiency.\u201d<\/span><\/p>\n

A previous study led by Voolstra showed that a compound found in corals called floridoside is increased, or upregulated, under high-salinity conditions. Floridoside is an antioxidant that also regulates osmotic pressure within the animal. This means it may counter the stress-induced overproduction of toxic reactive oxygen species within cells and help prevent severe bleaching.\u00a0<\/span><\/p>\n

\u201cSo we know thermotolerance is increased at high salinity for certain host-symbiont relationships and that floridoside is abundantly present at high salinity,\u201d says Gegner. \u201cNow we need to determine if floridoside is the molecule that confers thermotolerance within specific host-symbiont relationships. We also need to conduct experiments in actual corals to understand how this might affect both individual corals and reef ecosystems.\u201d<\/span> <\/p>\n","protected":false},"excerpt":{"rendered":"

Corals living in highly saline waters may be more tolerant to rising water temperatures. Scientists have long suspected that corals living in very salty water can also tolerate higher water temperatures, but the link has never been verified. Now, KAUST researchers have shown that salinity directly influences the ability of the coral model organism Aiptasia […]<\/p>\n","protected":false},"author":6,"featured_media":14612,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[16,17],"tags":[],"class_list":["post-14611","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-biology","category-research"],"featured_image_urls":{"full":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/03\/5340.jpg",722,350,false],"thumbnail":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/03\/5340-150x150.jpg",150,150,true],"medium":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/03\/5340-300x145.jpg",300,145,true],"medium_large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/03\/5340.jpg",722,350,false],"large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/03\/5340.jpg",722,350,false],"1536x1536":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/03\/5340.jpg",722,350,false],"2048x2048":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/03\/5340.jpg",722,350,false],"ultp_layout_landscape_large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/03\/5340.jpg",722,350,false],"ultp_layout_landscape":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/03\/5340.jpg",722,350,false],"ultp_layout_portrait":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/03\/5340.jpg",600,291,false],"ultp_layout_square":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/03\/5340.jpg",600,291,false],"newspaper-x-single-post":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/03\/5340.jpg",722,350,false],"newspaper-x-recent-post-big":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/03\/5340.jpg",550,267,false],"newspaper-x-recent-post-list-image":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/03\/5340.jpg",95,46,false],"web-stories-poster-portrait":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/03\/5340.jpg",640,310,false],"web-stories-publisher-logo":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/03\/5340.jpg",96,47,false],"web-stories-thumbnail":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/03\/5340.jpg",150,73,false]},"author_info":{"info":["Amrita Tuladhar"]},"category_info":"Biology<\/a> Research<\/a>","tag_info":"Research","comment_count":"0","_links":{"self":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts\/14611","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/comments?post=14611"}],"version-history":[{"count":0,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts\/14611\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/media\/14612"}],"wp:attachment":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/media?parent=14611"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/categories?post=14611"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/tags?post=14611"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}