As we headed to the end of the Define stage, it was clear that we had to go through an identification of key ‘ghost gear types’ types – especially the collections of pieces that were gathered up on beach cleans by members of the public, which varied in quality and quantity.
At the studio after collection, each material had undergone a manual cleaning process to remove biological contaminants (such as seaweed etc) and wash residue and sediments from the nets. All material was soaked in warm, soapy water (using a marine friendly soap by Ecover), left for half an hour, then rinsed in clean water and left to air dry thoroughly.
This method was simple, yet we believed would be sufficient for the needs of this project, which was to determine the possibility of recycling nets as a concept. There are however, further issues that would need to be considered – especially with nets that are collected from the sea / beaches and by volunteers / ‘collectors’:
- POP (persistent organic pollutants) – these can adhere to nets over time, and as nets can be ‘lost’ for significant amounts of time at sea, the possibility for contamination is quite high. This would need to be considered if a scaled version of the project was created – especially if the end product was to come in continued contact with skin. (NB – it was for this very reason that we decided early in the project to NOT create any product concepts that would come into contact with food / the mouth for example)
- Time – washing and sorting small sections of nets and net fragments is time consuming.
- Wastage can be high – especially if there is a high level of organic contaminants that has not been removed by the ‘collector’.
With this in mind, the large quantities of net that can be obtained at end-of-life directly from fishers are a better option:
- Contamination – could be lower (both of POP and certainly for visible organic matter such as seaweed)
- Time – washing would still be required, but sorting would not need to take place as the nets would be of one material sort.
- Wastage percentage would be lessened – especially if net was collected regularly from portside rather than letting it be stored in the open air.
However, using nets and fragments that have been collected by members of the public also has advantages:
- Making use of material that would otherwise be landfilled / incinerated after beach cleans.
- Engaging public in the issues with ‘ghost gear’ generally.
- Enabling products to be ‘tagged’ as being made from material collected on a certain date / location, which adds to their story and possibly desirability.
Quantifying the material – beach cleans…
We had split each of the collected and cleaned materials from beach cleans into seven different types:
- Type 1 – monofilament (nylon)
- Type 2 – Green trawl net (polypropylene)
- Type 3 – Orange trawl net / baling rope (polyethylene)
- Type 4 – Black baling rope (polyethylene)
- Type 5 – mixed rope fragments (mixed materials, some with internal cores of polystyrene for floating rope, or lead beading for sinking rope)
- Type 6 – various (unidentified mixed materials)
- Type 7 – miscellaneous fishing gear materials / items (this included floats, rope wheels and parts of crab/lobster pots)
Each location had a different build-up of material and slightly differing environmental conditions, but a pattern of the most frequently found material emerged:
It is worth noting that some areas had large collections of one material, such as rope, which skewed the results slightly, but overall, there was a similar pattern to the materials found.
- Nylon (Type 1) was relatively low in quantity
- Rope and mixed materials were quite common
- Green PP trawl net (Type 2) was the next most commonly found material. However, the USABLE material discovered across all sectors was only 5152g, with the total UNUSABLE net totalling 1522g – nearly around a third.
This material can be compared against the quantities available directly from the fishers themselves at end-of-life, which, after speaking to local representatives of the fleet would be in the region of 150,000g (150kg) per trawl net (based approximately on a 10 fathom Green PP braided net which forms our Type 2 material). As already discussed, this net would end-of-life, so would have far less contaminants, be pure, and would also help remove the net that is problematic for the fishers themselves.
If we could then monetise this material to create a product, the ‘raw material’ of the net could be purchased from the fishers, even for a nominal fee rather than them having to pay for it to be sent to landfill / incineration (at the current rate of £88.95 per tonne from April 1 2018).
Material choice for Project Net·Worth…
As far as raw material values go, nylon (and nylon 6 in particular) has the highest resale value – and is the material that Plastix and other industrial recyclers desire the most. The mixed materials found in the UK and raw material values are one of the reasons why the recycling scheme from the South Coast to Denmark with Plastix was not economically viable and suffered a loss per trip (as described in WK 8). However, if the most commonly found material (Green PP trawl netting) could be utilised locally – collected, recycled and reprocessed, this would allow for the more valuable nylon to be stored for less regular pickups by Plastix or similar whilst also creating a more regular income for the fishers.
It was decided that Project Net·Worth would progress with the green PP trawl netting (example below) as the primary feedstock material for reprocessing investigations