COMMENTS & OBSERVATIONS

Following the abortive attempt at a dive excursion last Sunday, due to an un-forecasted increase in wind strength, we decided this time to leave from the Mooloolah River, head north and tuck inside the north side of Mudjimba Island just in case a similar wind increase occurred for the forecast southerly. We had not dived the North West Reef site at Mudjimba Island for quite some time and it usually proved rewarding in species numbers recorded. On the surface there was some swell moving through and the visibility looked unpromising but we are optimists if nothing else and took the plunge. Visibility was low and the surge annoying but we persevered nevertheless, however the sightings were disappointingly low.

Taxonomic Diversity:
7 of the 8 species sighted were nudibranchs, with all being dorids (88% the overall total) comprising 0 x phanerobranch (non-retractile gill), 2 x porostomes (suctorial feeders and all Phyllidiidae family) and 5 x cryptobranchs (retractable gill) (all belonging to the Chromodorididae family). The other single non-nudibranch sea slug species was a Sacoglossan. If diet is considered then 7 of the 8 species sighted are spongivores.

Our Historical Data:
– This excursion brings the survey number to 44 at this site since we commenced fully recording data here on 04/10/2011.
– 165 species have been recorded at this site.
– Other than Chromodoris elisabethina, which has only been recorded by us at this site on four previous occasions, all species recorded on this survey are commonly recorded at this site.
– This is the fewest number of both species and overall number of organisms we have recorded at this site on our surveys (see graph in image gallery below), possibly a result of the prolonged period of poor weather exacerbated by the low visibility and surge on this dive.
– This site last surveyed on 25/08/2020.

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

TOTAL SPECIES SIGHTED: 14 (6/5)

DIVE IMAGES GALLERY

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