I was excited about returning to the Seychelles eleven years after surveying 12 sites during my Churchill Fellowship travel. I remember all the dives well, especially two of them, which are still vivid in my memory as two of the best dozen or so dives I’ve done anywhere in the world. Huge granite blocks and slopes, covered in corals and teeming with life. Tunas and massive humphead parrots swimming past.
As well as returning to the same sites to document any change 11 years on, the plan this time was to train up Kaylee Smit and Matt McLean. Kaylee and Matt are two of the growing international network of RLS scientific collaborators, both keen to tie RLS activities into their research activities in their parts of the world (South Africa and USA). Stuart Laing (the University of Seychelles) was also hoping to join us in the water, but ended up in an evening data support role due to work commitments. It turned out to be a great little team for the adventure.
Liz at Big Blue Divers was super helpful and planned the itinerary for the four days around our needs, and we managed to resurvey all 12 sites, scoring 245 reef species in the process. Without wanting to shed a negative light on the Seychelles (which is a truly spectacular place to visit), the impacts of the 2016 mass coral bleaching event were unfortunately stark at many of the sites we surveyed. My two favourite sites were now just bare granite slopes and piles of rubble, with few fish to count or see swimming past. Not all sites changed for the worse though, and a memorable dive at the “Aquarium” felt exactly like it was in 2012, with hovering schools of Myripristis violacea covering the reef like a cloud over a mountain top.
The species list continued to grow as more surveys turned up the odd individual of species not scored in 2012 (even if they were there and just managed to escape the transect blocks). But interestingly, I didn’t even catch a glimpse of a few species that were very common back in 2012, including a regional endemic butterflyfish, Chaetodon zanzibarensis (recorded on 75% of the transects in 2012, and not seen once this time). And how crazy not to see a single blue-green chromis (Chromis atripectoralis) anywhere across the 12 sites, after scoring schools of them on 60% of the transects in 2012 (and being super common right across the Indo-Pacific!). Likewise, the pretty little Hector's goby, (Koumansetta hectori), or coral-associated tubemouth wrasse (Labrichthys unilineatus) (both scored on 50% of transects in 2012) seemed to have disappeared. Whether these absences were related to sporadic recruitment from distant sources or are consequences of warmer waters or coral cover declines between the surveys, they do highlight the importance of the consistent, quantitative observations we do in RLS. Being able to confirm what isn’t there (or common enough to be seen on transects) anymore can be as important as what is there.
Eventually we’ll do some formal analysis of the data and try to better understand what has been happening more broadly, but for now the focus is still on continuing the effort to resurvey RLS sites around the world. Thanks to everyone helping with the effort, under and above the water.
Hoping to see some Chromis atripectoralis again soon…..
