COMMENTS & OBSERVATIONS

After 2 months of strong winds (Blow’n Bowen living up to its name) we finally have a nice forecast so time to check out Holbourne Island and do a spot of whale watching on the way. We were lucky to see a couple of small pods of dolphins (something we don’ t see that often here) and a mother whale and calf just chilling out on the way up. We also saw another couple of whales in the distance, so that was a tick for the whale watching.

We anchored up in about 6m of water and we could see the bottom so hopes were high for good visibility. Unfortunately the viz. on the bottom was not that great at around 8m and the deeper you went the worse it got, so we spent our time at a depth of no more than 7m. We found enough critters to keep us entertained for a short while but with the water being so chilly we called the dives short and although our overall count was acceptable, it was possibly lower than it would have been if the water was a few degrees warmer. We were serenaded by whale song throughout the dives so that was a bonus.

Taxonomic Diversity:
Sixteen of the twenty species sighted were nudibranchs, 14 being dorids comprising 9 x porostomes (suctorial feeders), 3 x phanerobranchs (non-retractile gill), 2 x cryptobranchs (retractable gill); and nil cladobranchs comprising 0 x aeolids, 2 x arminids and 0 x dendronotinids. Four sacoglossans complete the sightings. A total of 63 specimens were sighted. If diet is considered, eleven of the twenty were spongivores

Our Historical Data:
– We have now completed 19 surveys at Manta Reef since our first survey here on 13/03/2023.
– We have recorded 80 species at this site.
– Our most frequently recorded species here are Phyllidiella sp. a (58%), Phyllidia varicosa (53%), Phyllidiella cf. pustulosa (47%), and Phyllidiella zeylanica (42%).
– The most abundant species recorded by us at this site are Phyllidiella sp. a (1.8 per dive), Plakobranchus sp. 04 (1.4/ dive), Plakobranchus sp. 01 (1.1/dive), Thuridilla sp. 13 (1/dive).
– This is the first occasion on which we have recorded the species we are currently calling Phyllidiella cf. cooraburrama at this site. This species looks very similar to P. cooraburrama but has a pale mantle margin lacking in P. cooraburrama.
– Our last dive at this site was on 18/04/2026.
(Historical data courtesy of Terry Farr, who extracts it from his comprehensive database.)

Key to symbols
+++ New Species
+ First time sighted at Whitsundays
# Most commonly sighted at this site with %

TOTAL SPECIES SIGHTED: 20

DIVE IMAGES GALLERY

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