BYRON BAY’S VALLEY OF RAYS

Julian Rocks, off Byron Bay , is one of those dive sites that is always full of surprises. On a recent visit in January we were hoping to see a manta ray and harlequin shrimp that had both been sighted the day before, but instead had one of the most amazing stingray encounters we have every had.
    It all happened on Australia Day, we couldn’t think of a better way to celebrate Australia ’s national day than to head to Byron Bay for a day of diving. Arriving at Sundive at 7am, we loaded our dive gear onto Plucka Duck, one of the two large rigid hull inflatable boats that Sundive operate to the local dive sites daily.
    With skipper Jai, deckie and guide Mark, and a group of very keen underwater photographers ready to go we climbed into the back of the troop carrier for the quick drive to the beach to launch the boat. It was a beautiful day for diving; sunny, warm, light winds and slight seas. The crew quickly launched the boat and we were off to explore Julian Rocks.
    For our first dive we tied up to the Nursery mooring, on the western side of Julian Rocks, and the plan was to swim around The Needles, where the manta ray had been seen, to Hugo’s Trench, where the harlequin shrimp was, on the south-eastern side of the rocks.
    Upon entering the water the visibility wasn’t the best, eight to 12m, not the 30m it had been days before due to northerly winds. We quickly crossed the rocky bottom at The Nursery seeing lots of hard coral, blue gropers, octopus, anemonefish, moray eels and a couple of shy leopard sharks. On thing we did find unusual was the large number of blue spotted stingrays, it is common to see a few on a dive at Julian Rocks, but we were seeing dozens, but all singular.
    Arriving at The Needles we explored a series of gutters and bommies coated in lovely soft corals and sponges. As we drifted through The Needles we had large mackerels and barracuda swimming over head and also saw wobbies, turtles, eagle rays, several black blotched stingrays and a few more leopard sharks. The blue spotted stingrays were also getting thicker, now in groups of twos and threes.
    Exiting The Needles we next came to Elwood’s Trench. This wide sandy gutter was just packed with blue spotted stingrays; in front of us we could see thirty to forty of these small rays. Some were just lying on the bottom, but others were heading up the trench, so we followed. The further we went up the trench the thicker the blue spotted stingrays became. At the end of the trench, where the sand gives way to a slope of boulders, the number of rays was just amazing, there must have been several hundred rays either swimming about or lying on the bottom.
    For the next ten minutes we watched and photographed the rays as they swarmed about the trench. But they weren’t the only creatures here as between them were swimming several large black blotched stingrays and white-spotted shovelnose rays, while above were schools of kingfish, trevally, snapper and sweetlips – a real fish soup!
    Why were all these blue spotted stingrays aggregating we wondered? There appeared to be no breeding behaviour, and most of them appeared to be female and this was after the normal breeding season in spring. Were they pregnant females gathering to pup? But none of them looked pregnant, unlike several of the black blotched stingrays with huge bulges on their backs. Were they gathering to feed? We were very puzzled.
    After returning to Sundive for morning tea, we head out for a second dive and this time Jai tied up at the mooring at Elwood’s Trench. We first ventured into nearby Hugo’s Trench, the harlequin shrimp long forgotten, to see if the blue spotted stingrays were also in here. But there were only a handful of rays; instead saw large wobbies, turtles and schools of bream, sweetlips, snapper and morwong.
    We returned to Elwood’s Trench and at first we thought that all the rays had dispersed, as there were much fewer at the entrance to the trench. However, we soon found out why as there were even more at the end of the trench, there must have been over a thousand rays swarming on the sand and boulders. This seething mass of blue spotted rays was an amazing sight; some were lying on the bottom, some under the sand, other were lying on top of other rays, but the vast majority of them were swimming around in a giant chaotic flock.
    We observed and photographed the rays for another twenty minutes hoping to get a clue as to why they were aggregating, but again didn’t see any behaviour that hinted why they were gathering in such large numbers. From our knowledge of rays we knew that this was very unique behaviour, as far as we knew only two other species of stingray had been known to aggregate, and this was for breeding.
    Later speaking to Phil Buckland, one of Sundive’s most experienced dive guides, he informed us that the rays aggregated each summer for several weeks. We had always avoided visiting Byron Bay during the peak of summer, to avoid the holiday crowds, so had missed this amazing and unique gather of stingrays in the past. But will now be keen to visit each summer.
    The aggregation of blue spotted stingrays will no doubt have disappeared by the next time we visit Byron Bay , but there is always something special happening at Julian Rocks that makes it one of Australia ’s best dive sites.

Article appeared in Dive Log No.273 April 2011

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