Warming sea temperatures, El Nino, Crown of Thorn Starfish. After all of these threats to reef health, it’s no wonder Maldive reefs have been struggling. And now a fourth (!) assailant entered the scene – Indian Ocean Dipole. The BBC describes the IOD, aka “The Indian Ocean El Nino” (“Indian Ocean Dipole – What Is It?”):
- “Temperatures in the eastern part of the ocean oscillate between warm and cold compared with the western part, cycling through phases referred to as “positive”, “neutral” and “negative”. The dipole’s positive phase this year – the strongest for six decades – means warmer sea temperatures in the western Indian Ocean region, with the opposite in the east.”
And this added boost to ocean temps isn’t only a hazard to corals, but to other life in the atolls. Notably, in the recent loss of mangroves as examined in this month’s Nature article “Sea-level rise and extreme Indian Ocean Dipole explain mangrove dieback in the Maldives”:
- “Mangrove forests enhance Small Island Developing States’ resilience to climate change, yet in 2020, a mangrove dieback impacted ~ 25% of mangrove-containing islands in the Maldives…We attribute this dieback to salinity stress driven by record-high sea levels in 2020, linked to an extreme positive Indian Ocean Dipole event.”
