[Coral-List] Coral colonization of lava flows - video

[tomascik at novuscom.net]

Hi everyone,

A few weeks ago I posted an old underwater video footage of a 5 year old 
coral community that became established on a new andesitic lava flow 
following the 1988 eruption of Gunung Banda Api, Indonesia. The video 
documented the coral community from 1992 to 1994. My OneDrive had a hard 
time with all the traffic, but I hope that most of you who were 
interested seeing the video were able to do so. If you were not able to 
see it and would still like to have a look please let me know and I’ll 
send you OneDrive or DropBox link.

Following the 1992 visit to Banda Api, when I saw just how fast coral 
communities can recover following a catastrophic event, I kept wondering 
how the coral community on the lava will look like in a few decades. 
Well, I actually got a chance to see just that when in 1993 we did a 
mini-expedition up the Sangihe Islands as part of our work on “The 
Ecology of the Indonesian Seas”. We were fortunate enough to visit Ruang 
Island which, like Gunung Banda Api, is a stratovolcano. During Ruang’s 
1949 volcanic eruption a high viscosity andesitic lava flow came down 
the eastern slope and spilled into the sea creating a new habitat. Lavas 
from both Banda Api and Ruang volcanoes are very similar, since they are 
formed at destructive plate boundaries from melting crust and thus they 
both are rich in silica and produce high viscosity lava flows. In 
contrast, lava flows on Reunion and Hawaii islands are basaltic low 
viscosity lavas formed over a hot spot, thus they are very different in 
both physical and chemical properties from the Banda Api and Ruang 
lavas. When we did our dives on the Ruang lava flow in 1993, 44 years 
have passed since the catastrophic event. I thought that some of you may 
be interested to have a look at the 44 year-old coral community. Recent 
paper by Jouval et al. (2020) 
(https://doi.org/10.1038/s41598-020-77665-z) on coral colonization of 
basaltic lava flows on Reunion Island highlight the role that different 
lava flows and environmental settings may play in coral colonization 
trajectories and ecological succession.

Here are OneDrive and Dropbox links to the Ruang lava flow video clip:

https://1drv.ms/v/s!Aq1K6CQCBeATgtZiHMO8BXU8JyDb6w?e=ZJEBNt

https://www.dropbox.com/s/rltm5su2lkssv6d/Rebirth%20of%20a%20Coral%20Reef%20Ruang.mp4?dl=0

  “Nature is painting for us, day after day, pictures of infinite 
beauty.”
- John Ruskin

How true when you consider hot lava spilling into the ocean as a new 
canvas, and the coral reef as nature’s evolving work of art. The rebirth 
of coral communities (and hopefully eventually reefs) on Gunung Banda 
Api and Gunung Ruang clearly demonstrate the power of nature. In both 
instances the volcanic eruptions resulted in total destruction of coral 
reefs, but unlike in many other places around the world there was a 
rapid coral recovery. These two tales are a good example what happens on 
local scales where nature is relatively free from anthropogenic impacts. 
It is also clear to me that when it comes to ‘canvas’ choice for coral 
reef portraits, nature definitely prefers andesitic lavas.

Cheers,
Tom