Research press release


Communications Biology

Environment: Coral species at risk of extinction in Mexican Caribbean due to deadly disease

メキシコ沖のカリブ海で、約450 kmにわたるサンゴ礁系の調査が行われ、イシサンゴ組織喪失病の発生によって、一部のサンゴ種の死滅率が最大94%に達していることが明らかになった。こうした知見は、この地域の一部のサンゴ種の絶滅を防ぐために人為的介入が必要なことを浮き彫りにしている。これらの結果を報告する論文が、今週、Communications Biology に掲載される。


今回、Lorenzo Álvarez-Filipたちの研究チームは、2016年から2017年の間(イシサンゴ組織喪失病がメキシコ沖のカリブ海に拡大する前)に35か所の調査を実施し、2018年7月から2020年1月の間(イシサンゴ組織喪失病がメキシコ沖のカリブ海に出現した後)に101か所の調査を実施した。

Álvarez-Filipたちは、イシサンゴ組織喪失病がメキシコ沖のカリブ海で大発生した後に調査したサンゴ群体(2万9095)のうち、17%が既に死滅し、10%がこの病気にかかっていることを明らかにした。調査対象のサンゴ種(48種)のうち、この病気にかかった21種の死滅率は、10%未満から最大94%の範囲だった。脳サンゴと迷路サンゴのグループに属する造礁サンゴ種が、最も深刻な影響を受け、迷路サンゴ種とDendrogyra cylindrus(柱サンゴ)の個体数が、80%以上減少した。これらの数値は、この地域に生息するサンゴ種の一部に絶滅の恐れがあることを示しており、Álvarez-Filipたちは、造礁サンゴ種の個体数減少が、サンゴ礁の環境変化に対処する能力を弱めるかもしれないという考えを示している。



An outbreak of stony coral tissue loss disease has led to mortality rates of up to 94% among some coral species in the Mexican Caribbean, according to surveys of a 450 kilometre reef track. The findings, published this week in Communications Biology, highlight the need for human interventions to prevent the extinction of some coral species within this region.

Stony coral tissue loss disease was first reported in Florida in 2014 and has since spread across the Caribbean. Previous research has found that the disease can kill infected corals within weeks, however prior to this study, the regional impacts and extent of population declines were unclear.

Lorenzo Álvarez-Filip and colleagues surveyed 35 sites between 2016 and 2017 — before stony coral tissue loss disease reached the Mexican Caribbean — and 101 sites between July 2018 and January 2020 — after the disease reached the region.

The authors found that of the 29,095 coral colonies surveyed after the outbreak in the Mexican Caribbean, 17% were already dead and an additional 10% were afflicted with the disease. Out of 48 species surveyed, mortality rates among the 21 afflicted with the disease ranged from less than 10% up to 94%. Species belonging to the reef-building maze and brain coral groups were the most severely affected, with maze coral species and the pillar coral Dendrogyra cylindrus experiencing population losses greater than 80%. These numbers indicate that some species are at risk of extinction within the region and the authors suggest that the loss of reef-building species could impair the ability of coral reefs to cope with environmental changes.

In addition to population losses, the researchers observed a 30% reduction in the ability of coral communities to produce calcium carbonate, the material required to make the complex three-dimensional structures of coral reefs. They propose that this could lead to reef frameworks being destroyed faster than they are produced.

The authors conclude that stony coral tissue loss disease could become the most deadly disturbance ever recorded in the Caribbean. Human interventions such as rescuing colonies of vulnerable species, preserving their genetic material, and implementing restoration efforts will likely be needed to facilitate reef recovery and prevent the region-wide extinction of some species, they add.

doi: 10.1038/s42003-022-03398-6


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