Peka Peka beach after storm

[GrahamB]

Hi,

just got back from a walk along Peka Peka beach (road end to the small estuary to the north - ca. 1km) as soon as the rain cleared today. As expected, the wave surge had cut right into the dune front. Immediately apparent was the very large numbers of stranded goose barnacles. Rather than attached to the usual wood or other flotsam, these were all in small groups attached to what looks like a gelatinous sponge. It is probably autocthonous though, with a small debris particle in the centre. I don't know what species this is yet but will probably find out when I next visit the Crustacean department in Te Papa.


Another nice find was a new Janthina for me - Janthina globosa, rather than the more common J. exigua. This species has a "spout-shaped" anterior (siphonal) canal.



Also one fresh Common Diving Petrel corpse.

As is usual now, Claire and I take a plastic bag whenever we go to the beach at Waikanae and pick up plastic. Fairly paltry in the big scheme of things but it is surprising how it soon mounts up. This is today's haul from the 1km Peka Peka stretch (and doesn't include all the very small, <5mm stuff that was there) - banana just for scale!


Cheers,
GrahamB

[Colin Miskelly]

Hi Graham

Mary McEwen found a similar bunch on Waikanae Beach last week. Rick Webber (Te Papa Crustacea curator) identified them:

"This organism is indeed a barnacle, called a buoy barnacle (Dosima fascicularis) because it makes its own flotation device rather than attaching to some bit of floating flotsam. It is a stalked barnacle in the family Lepadidae as are most of the stalked barnacles you see commonly washed ashore attached to fishing floats, bits of wood, polystyrene etc.

In your photo you can see the float in the centre with the short-stalked barnacles attached round it like petals. They come ashore mainly on the west of the North Island but don’t seem to be found nearly as often as the more common species of lepadids. most of which belong in the genus Lepas. "

His reply fits your image perfectly

Cheers
Colin

[GrahamB]

Hi Colin,

these goose barnacles were very abundant today - I've not seen this form, or so many before, and I didn't have a key at hand to identify them. Thanks for the ID via Rick - I hope to get in to see him next week anyway.

Shame about all the "wrong" albatross/petrel/shearwater food - lots of it blue and therefore very attractive to pelagic feeders.

Cheers
Graham

P.S. went down to the Waikanae spit on Saturday about 2.00 pm before the rain set in. Again about 300 WF terns. I didn't see any BF terns although Roger Smith photographed a couple of juveniles there on Friday. No sign of the Gull-billed.