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Dive Report

18-12-2021 La Balsa Park

Dec 19, 2021

DAY/DATE

Saturday

18/12/2021

SITE/S

La Balsa Park

 

PARTICIPANTS

Julie, Terry & David

 

TYPE

Subtidal

 

MODE

Shore Entry

 

VESSEL

 

DIVE

1

 

SITE/S

La Balsa Park (Fish Cage Entry)

 

SPECIES #

24

 

DURATION

149 Min

 

DEPTH/RANGE

To 6.1 m

 

TEMP.

27 C

 

VIS.

5 m

 

SURGE

 

CURRENT

Usual tidal run

 

COMMENTS & OBSERVATIONS

The Park was fairly quiet at 06:00 am. We entered and descended at the Fish Cage Stairs. The park may have been quiet however it was anything but under the water. The water traffic was constant and some of it very noisy indeed. Terry and David are still spending much of their time working to come to grips with the new photographic rigs rather than searching for subjects. Hydroid coverage seems to be down somewhat explaining the drop in specimen numbers of aeolids recorded, apart from Flabellina lotos. Even the specimen count of Goniodoridella sp. 01 has plummeted. The sponge eaters Goniobranchus daphne and Hypselodoris obscura are still well represented though. A specimen of headshield slug – Philinopsis speciosa – was recorded – just – as a fish swooped in and devoured it before the second photograph could be taken. Upon exiting the water we found the park to be just as busy as the waterway, being a hive of activity with many and varied pastimes being enjoyed by a cross section of the community.

Taxonomic Diversity:
Out of the species total of 24: 11 were cladobranchs with all but 1 being aeolids. A further 11 were dorids comprising 4 x cryptobranchs (contract gill into a pocket), 6 x phanerobranchs (unable to retract gill) and 1 x porostome (radulaless suctorial feeder). The balance was completed by 1 x cephalaspidean and 1 x sacoglossan.

Our Historical data:
– 87 surveys conducted at this site since the first on 08/03/2014.
– Last surveyed 05/11/2021
– 225 species recorded by us at this site.
– Our most commonly recorded species at this site are: Hypselodoris obscura (90%), Goniodoridella sp. 1 (85%), Goniobranchus daphne (79%), and Flabellina rubrolineata (69%).
– This is the first time we have recorded Dendrodoris nigra at this particular site.
– There are dramatic fluctuations in the number of organisms we record at this site but, overall, the number of species recorded per survey seems to be relatively constant – see graph below in the Image Gallery.

Guide to Symbols:
+++ New Species
+ First time sighted at this site
# Most commonly sighted at this site with %

TOTAL SPECIES SIGHTED: 24

 

SPECIES LIST – ALPHABETICAL

Cratena lineata -7
Cratena sp,. 07 -1
Dendrodoris nigra -2 +
Dermatobranchus oculus -1
Eubranchus sp. 10 -1
Flabellina lotos -54
Flabellina rubrolineata -11 #69%
Goniobranchus daphne -21 #79%
Goniobranchus decorus -1
Goniobranchus geometricus -3
Goniodoridella savignyi -1
Goniodoridella sp. 01 -15 #85%
Goniodoridella sp. 06 -1
Gymnodoris sp. 09 -1
Gymnodoris sp. 10 -1
Gymnodoris sp. 13 -2
Hypselodoris obscura -9 #90%
Philinopsis speciosa -1
Tenellia sp. 23 -1
Thuridilla carlsoni -3
Unidentia sp. 01 -1
Unidentia sp. 02 -1
Unidentia sp. 05 -1
Unidentia sp. 11 -1

SPECIES GROUPED BY ORDER

Nudibranchia
Cratena lineata -7
Cratena sp,. 07 -1
Dendrodoris nigra -2 
Dermatobranchus oculus -1
Eubranchus sp. 10 -1
Flabellina lotos -54
Flabellina rubrolineata -11 
Goniobranchus daphne -21 
Goniobranchus decorus -1
Goniobranchus geometricus -3
Goniodoridella savignyi -1
Goniodoridella sp. 01 -15 
Goniodoridella sp. 06 -1
Gymnodoris sp. 09 -1
Gymnodoris sp. 10 -1
Gymnodoris sp. 13 -2
Hypselodoris obscura -9 
Tenellia sp. 23 -1
Unidentia sp. 01 -1
Unidentia sp. 02 -1
Unidentia sp. 05 -1
Unidentia sp. 11 -1

Cephalaspidea
Philinopsis speciosa -1

Sacoglossa
Thuridilla carlsoni -3

Umbraculoidea

Pleurobranchoidea

Anaspidea

DIVE IMAGES GALLERY

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