Thursday, April 30, 2020

'Last to Sea' #2 - Abalone

Work continues on this year's contribution to the Elora Sculpture Project : 'Last to Sea'
Overall installation rough

"  d) Abalone - forged from a single plate, (about 10 inches). Several types off North American almost extinct through over fishing. Unchanged for 70 million years, through 1 Extinction Event (the ‘youngest’ type portrayed).  "

Living abalone showing epipodium and tentacles, in display tank at Ty Warner Sea Center on Stearns Wharf, Santa Barbara, California. (image from Wikipedia)
In total, abalone are found world wide, with 56 different species. They have been exploited, primarily as a food source, by humans since pre-history. (Tracing size of shell middens over time has shown over harvesting leading to declining populations in local areas is also consistent through human actions.) 
" According to a status review by Alistair Hobday and Mia Tegner1, an estimate of the total abundance of white abalone in California and Mexico is around 1,600 animals. This is less than 0.1% of the estimated pre-exploitation population size. This reduction has occurred in the last 30 years. "

" Although this piece of information would seem to provide hope for recovery, actual densities (20 white abalone/ha, at best) are not high enough to allow for reproduction. At present densities the probability of reproduction in the wild is believed to be close to zero because a male and female must be within a few meters to spawn successfully. "

National Oceanic and Atmospheric Administration (USA)
It could be argued that strictly speaking, it is not Climate Change that is the cause of the virtual extinction of the white abalone. Direct Human Impact, via over harvesting, is most certainly the reason. In the USA, the pink and green abalone are also on the Endangered List.

There is reference (on Wikipedia) that changes in acidification of sea water (caused by increasing atmospheric C02 levels) increasingly impact proper shell formation by abalone.
Increasingly, stocks of wild abalone (those species considered large enough for food source) are rapidly declining world wide. This has lead to a successful 'ranching' industry (especially in Australia). There abalone are seeded into human constructed, but still open ocean, 'farms', for later harvesting.

A living White Abalone
In creating a sculptural version of an abalone for 'Last to Sea', I picked up on a number of visual aspects (blending of the two reference images) :
1) Overall shape and size (white abalone described as 'up to 10 inches')
2) Shell above with living mantle below
3) Distinctive line of holes along one edge of shell
4) Cluster of tentacles to one end

The material chosen was 1/8 thick mild steel plate (which I have a large quantity of, gathered as scrap off cuts).
The shell portion was created first. The oval shape was rough cut with a torch, then the edges ground smooth. This piece was heated in the gas forge, then dished using a bowl shaped bottom tool and a wide faced crowning hammer.
After first dishing step - Piece 'just' fits into my 2 burner gas forge.

Once the overall dished form was hammered in, this was adjusted to sit more or less flat around the edges.
Next step was to indent the metal to form the line of 'vent holes'. This was done working from the inside surface, using a ball headed punch. The punch forced the surface down into small diameter dishing stake. I had to have assistance (thanks to Kelly Probyn-Smith here) to hold the plate in place over the stake while I positioned the punch in one hand and hammer in the other. In some cases, the extruded plate ended up tearing a the bottom of the shape. These were trimmed and edges softened afterwards.

The next step was cutting the second piece that would serve to suggest the fleshy mantle.
Finished shell, next to rough torch cut plate for the mantle.
In the image above, you can see how the outline of the shell piece was traced to the starting plate, with the cut line running just beyond it. Quite specifically (!!) I over heated the cutting process with the torch. I also deliberately let the cut waver back and forth. This edge was not ground to smooth any of the blobs from overheating. The overall effect is to create a more 'natural' looking organic line.

Four short pieces of 1/4 inch diameter round rod were forged into long tapering points. These were cut to random lengths, then quickly forged to irregular S shapes.

For final assembly, a long bolt was welded to the bottom plate. This will be used to secure the sculpture to a natural stone slab base.
The four tentacles were welded in place along one edge of the bottom plate.
Working from inside four holes drilled into the bottom plate that would fit along the edge of the shell, the two pieces were welled together.

Finished 'Abalone' element
Again, quite intentionally, I am leaving all the individual sculpture elements within 'Last to Sea' with their natural forged / fire scale surfaces. This creates a mottled dark grey colour when the piece is first installed. This will certainly rust with time as the pieces weather. The transition from 'as forged' to rust is also intended as a refection of loss over time.

Next up : Horseshoe Crab

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February 15 - May 15, 2012 : Supported by a Crafts Projects - Creation and Development Grant

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