{"id":2635,"date":"2024-03-08T09:55:13","date_gmt":"2024-03-08T09:55:13","guid":{"rendered":"http:\/\/versicolor.ca\/barbados\/?page_id=2635"},"modified":"2026-02-04T12:05:39","modified_gmt":"2026-02-04T12:05:39","slug":"effects-of-2023-extreme-warming-events-on-millepora-spp","status":"publish","type":"page","link":"https:\/\/versicolor.ca\/barbados\/observations-ii\/vauxhall-reef-environs-2024\/effects-of-2023-extreme-warming-events-on-millepora-spp\/","title":{"rendered":"Effects of 2023 extreme warming events on Millepora spp"},"content":{"rendered":"

NAVIGATION
\nThis page is a sub-page of Vauxhall Reef & Environs 2024.<\/strong><\/a><\/small>
\nVauxhall Reef & Environs 2024<\/strong>\u00a0is a sub-page of ObsII<\/a> a top-level page on the website Barbados Fringing Reefs and Seagrass Beds<\/a> (www.versicolor.ca\/barbados).
\nGo to ObsII<\/a> to view a list of all pages and subpages under ObsII<\/small><\/p>\n

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Some good news: Millepora alcicornis<\/em> on Vauxhall Reef was largely unaffected by the extreme warming events in the fall of 2023<\/strong><\/p><\/div>\n

Note: I am recognizing only two species of Millepora<\/em> at Vauxhaul and nearby fringing reefs: M. complanata<\/em> and M. alcicornis<\/em> (see Taxonomic Issues<\/a>).
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Tom Goreau<\/a> cited the Acropora<\/em> and Millepora<\/em> species as the reef-building species most affected by extreme warming in the fall of 2023.<\/p>\n

The loss of Milleporas in 2023 was perhaps unexpected, re: comments by E. Penessi, 2022 in “How does Caribbean fire coral thrive as others vanish?<\/a>” (Article on science.org) she cites Peter J. Edmunds 2022 in proc. Roy Soc B: Persistence of a sessile benthic organism promoted by a morphological strategy combining sheets and trees<\/a>. However in his review, Lewis 2006, p 30 describes many bleaching events affecting Millepoa species. *Biology and Ecology of the Hydrocoral Millepora on Coral Reefs<\/a> in ADVANCES IN MARINE BIOLOGY<\/em> VOL 50<\/small><\/p>\n

Both the “true” coral\u00a0A prolifera<\/em> and the coral-like hydrozoan\u00a0 M. complanata\u00a0<\/em>occur, with the colonial\u00a0 zoanthid\u00a0\u00a0Palythoa caribeana,\u00a0<\/em>in the “A. prolifera<\/em> Mother Colony Complex<\/a>” at Vauxhall.<\/p>\n

Both\u00a0A prolifera<\/em> and\u00a0M.\u00a0complanata <\/em> were uniformly drab and covered with epiphytic growth when I viewed the colony on Jan 12, 2023, in sharp contrast to the vibrant colours of a year earlier (Palythoa\u00a0caribeana <\/em>was ‘normal’ in both years)\u00a0<\/em>:<\/p>\n

Click on images for larger versions<\/em><\/p>\n

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“A prolifera<\/em> Mother Colony Complex” in early 2023 (left) and early 2024 (right)<\/strong>
They are taken from different vantage points;
the M. complanata<\/em> colony at bottom left in the 2023 photo is at top right in the 2024 photo<\/p><\/div>\n

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Closeup of the same M. complanata<\/em> colony in early 2023 (left) and early 2024 (right)<\/strong><\/p><\/div>\n

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Close-up of M. complanata<\/em> in the Mother Colony on Feb 22, 2024<\/strong>. It illustrates how quickly the blades became colonized as the warming events were likely in Oct\/Nov, only 2-3 months earlier.<\/p><\/div>\n

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Coral head fromed by Millepora complanata<\/em>\u00a0 in the Reef Crest zone at Vauxhall, in 2017 (mosty living) and 2024 (mostly dead).<\/strong> Photos from slightly different vantage points.<\/p><\/div>\n

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I have called these castle-like formations of M. complanata<\/em>\u00a0that occur in the Seaward Slope “Cities of Gold”<\/strong>. They tend towards a ‘squarrose form’ (but I am not convinced<\/a> they are Millepora squarrosa<\/em>) and the individual compartments host a wide variety of sea life. This particular example is on Reef 32 in the MPA, but they also occur on Vauxhall Reef. All of the colonies I have observed in 2024 appear mostly dead, but still hosted\u00a0 the same variety and abundance of sea life. The closeup photos illustrate how quickly the blades became colonized –\u00a0 the warming events were likely in Oct\/Nov, only 2-3 months earlier.<\/p><\/div>\n

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Millepora alcicornis<\/strong><\/em> and M. complanata<\/em> on spurs, Seaward Slope Zone in 2015 and 2024.\u00a0<\/strong>Photos are in different stands but are representative: both species healthy and common 2015…mid 2023, as at left. In early 2024: most A. alcicornis was\u00a0 unaffected<\/em>, most M. complanata<\/em> had died (re extreme warming\u00a0 in Oct, Nov 2023)<\/p><\/div>\n

In regard to the Acropora<\/em> species: because their distribution is limited at Vauxhall and I have a lot of photos from earlier years,\u00a0 I was able to make some estimates of the degree of dieback due to the 2023 warming events. It was highly variable\u00a0 between specimens for A. palmata<\/em> (0-100%); evidently 100% for A. prolifera<\/em> (no regrowth observed, at least up until March 2024), and slightly less than 100% for A. cervicornis <\/em>(see this page<\/a> for details).<\/p>\n

To date in 2024, I\u00a0 have observed a few small specimens of Millepora complanata that appeared not have been affected; in a few – mostly on spurs close to the Reef Front – there was partial dieback. Otherwise virtually all specimens – many – I have seen look dead, but those could include specimens that aged earlier or were killed bu other factors.<\/p>\n

On the other hand, of about 20 sites where I have viewed M. alcicornis<\/em>, only at one was there any specimens\u00a0 that appeared to have died recently; in that case there was a much larger clump of living M. alcicornis<\/em> next to it.<\/p>\n\n\n\n
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M. complanata\u00a0<\/em>exhibiting partial dieback.<\/strong>(Some might call it M. squarrosa.<\/em>) Located at leading edge of a spur at Vauxhall, Mar 10, 2024,<\/p><\/div><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Update Mar 19, 2024<\/p>\n

I am noticing more partially living M. complanata and small specimens totally living, some examples below. I dont know whether I missed them previously or they represent new growth.<\/p>\n\n\n\n
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Reef 33, seaward slope Mar 17, 2024<\/p><\/div><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n","protected":false},"excerpt":{"rendered":"

NAVIGATION This page is a sub-page of Vauxhall Reef & Environs 2024. Vauxhall Reef & Environs 2024\u00a0is a sub-page of ObsII a top-level page on the website Barbados Fringing Reefs and Seagrass Beds (www.versicolor.ca\/barbados). Go to ObsII to view a … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"parent":2351,"menu_order":40,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-2635","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/versicolor.ca\/barbados\/wp-json\/wp\/v2\/pages\/2635","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/versicolor.ca\/barbados\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/versicolor.ca\/barbados\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/versicolor.ca\/barbados\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/versicolor.ca\/barbados\/wp-json\/wp\/v2\/comments?post=2635"}],"version-history":[{"count":49,"href":"https:\/\/versicolor.ca\/barbados\/wp-json\/wp\/v2\/pages\/2635\/revisions"}],"predecessor-version":[{"id":5018,"href":"https:\/\/versicolor.ca\/barbados\/wp-json\/wp\/v2\/pages\/2635\/revisions\/5018"}],"up":[{"embeddable":true,"href":"https:\/\/versicolor.ca\/barbados\/wp-json\/wp\/v2\/pages\/2351"}],"wp:attachment":[{"href":"https:\/\/versicolor.ca\/barbados\/wp-json\/wp\/v2\/media?parent=2635"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}