The yearly aggregation of camouflage grouper (Epinephelus polyphekadion) has been known for many decades in Palau. Scientists have come and gone since the late 70’s observing their patterns and protecting them and their vulnerable spawning sites around the islands during the months of June through to August. Since then no-one had witnessed or at least not documented any spawning style, timing or pattern in Palau until 2015 when Sam’s Tours Unique Dive Expeditions crew slowly put all the pieces of the puzzle together.
Over the last ten years spawning diving in Palau has become an addiction for a few pioneering dive shops. Finding an aggregation is like finding treasure, and once found the exact location should be kept secret or at least try to be kept secret from risk of overfishing or mass tourism. Once you find an aggregation of fish normally hundreds to tens of thousands which can be found consistently either yearly or monthly, you can start working on the formula of tide, moon and month to crack the code. This takes hours of in water observation to finally be able to say you can ‘nail it’.
Paul Collins and myself over the last six years spent large periods of time watching and observing the camouflage grouper fighting for territory, displaying sexual dimorphism (color change) but we had not witnessed spawning and neither had anyone else in Palau. We wanted to put that final piece of the puzzle to rest and so sat painfully at times watching and waiting each year passing by as their short window came and went.
As the fish only stayed at the site for a limited period of time, each year we would slowly tick off all the possible combinations of tide, moon and time until one day it all fitted together.
We were not expecting the camouflaged grouper (Epinephelus polyphekadion) spawning to be such a spectacle. Our other spawning expeditions of snappers (Lutjanus bohar) and bumphead parrotfish (Bolbometepon muricatum) had close to guaranteed bullsharks (Carcharhinus leucas) and oceanic blacktip sharks (Carcharhinus limbatus) during spawning time and that we thought was going to be hard to beat.
During the daytime we only saw a handful of sharks around this aggregation. A few whitetip reef sharks (Triaenodon obesus) and grey reef sharks (Carcharhinus amblyrhynchos), so our expectation levels were low on shark predation.
As night fell everything changed as large sickle-fin lemon sharks (Negaprion acutidens), which I had only seen a handful of times in Palau, begin to appear. These quite large and agile sharks, seek out the grouper using their sensors at night.
As the spawning time approaches more species of sharks begin to appear, grey reef and oceanic blacktip sharks lurk through the night. We have been studying the timing for years and what we have been so longing to see was just about to happen. The sharks have also been waiting. Their timing however is always on cue and when the sharks appear, the showdown is about to unfold. Unlike the lemon sharks these sharks find it hard to hunt under the corals. Their technique is to strike during a spawning rush.
As the spawning erupts our patient waiting is over and some of the questions we have been wondering our answered. Males push out their females that they have been protecting from their night time holes for several days, both rising to the surface spiraling like a mini tornado as they release their gametes.
Oceanic blacktip and grey reef sharks buzz through your lights trying to pick off the grouper as they spawn in front of you, their silhouettes lit up by our lights. The water becomes milky with milt and gametes and its time to find our exit line.
Its nice to get rewarded from time to time. Most of our dives learning these exact times can be very uninteresting. Hours of fish not really doing much at all, so when it all comes together you can imagine what comes out of our mouths when we break the surface…….