While on my morning walk, combing the beach for artist inspiration I came across this odd looking thing! It is hard and hollow.
I let the kids take it to school and see what the other kids think it is. I had a bit of a google and couldn’t find the answer myself.
I contacted NIWA (National Institute of Water and Atmospheric Research) via their Facebook page and they kindly contacted Marine Biologist Alan Hart who informed me of the following:
“It is a very distinctive swimbladder, it comes from this chap below:
(from: New Zealand Fishes Volume 1 A field guide to common species caught by bottom and midwater fishing).
The bladder is reasonably common on NZ beaches, mainly I presume due to the way the Porcupine fish can die in their inflated state (probably as by-catch to inshore trawlers discarding them). The buoyant body washes ashore inflated with air, the swimbladder intact and over-inflated due to the change in pressure when it was trawled from up to 320 m. The body is washed ashore to the high tide mark, dries in the sun and the bladder hardens fully inflated. Chances are the body is “popped” by seagulls or small boys and the swimbladder is detached, floating further down the beach or to a new location away from the body.Few other fish bladders have that combination of happenstance to produce such well preserved bladders, though many common inshore species have equally robust bladders.”