==========
Fri Oct 30 18:19:41 -0700 2020

Comparison of fishing efficiency between biodegradable gillnets and conventional nylon gillnets

Two experimental gillnets, well specified:

Each gillnet had 210 mm nominal mesh opening, was made of 0.7 mm monofilament, and was 30 meshes in height and 275 meshes long (approx. 55 m stretched length).

Consequently, an assembled gillnet was 27.5 m long and had a hanging ratio of 0.5.

https://www.netsandmore.com/123-how-to/246-hanging-ratios

relates hanging ratio to width-height ratios of mesh.
50%: 86% H 50% L

So, 275 meshes * 200 mm mesh * 50% hanging ratio = 27.5 m
30 meshes * 200mm mesh * 86% hanging ratio = 5.2 m

Catch was 

We used two sets of gillnets in the experiments. Each set consisted of 16 gillnets, with eight bio gillnets (B) and eight nylon gillnets (N).

A total of 5103 cod were caught in the 43 gillnets deployments that
were included in the analysis, with 2243 and 2850 cod caught by the
bio gillnets and nylon gillnets respectively. Daily catches that varied
between 73 and 498 cod. The mean effective fishing time (SD) (the time
the gillnets remained at the sea bed) was 21 h 14 min (4 h 54 min). The
mean (SD) fishing depth was 95.7 m (10.8 m).


Length-gutted weight reported in Walsh 2005 (see also) as
"Based on the total length–gutted weight relationship for northeast Atlantic cod W = 0.013×L^2.86 (Walsh and Hiscock, 2005)..."

Meanwhile, FAO http://www.fao.org/3/a-bt963e.pdf
reports Cod Gutted, head on * 1.2 = live weight
        Cod Gutted, head off * 1.69 = live weight


Anywayyys, figured it out
Effort/catch = ["lognormal", 7060, 1.013]  # m2h/t
Gear intensity = 0.0101 kg/ hung m2




