==========
Sun Oct 04 12:17:35 -0700 2020

Watanabe 2016 = "Life Cycle Inventory Analysis for a Small-Scale
Trawl Fishery in Sendai Bay, Japan"

Sustainability 2016, 8, 399; doi:10.3390/su8040399

Key data: inventory of a fleet of 10 "small" trawlers
the inventory model is simplified.

good list of references to check

Not clear whether they accounted for gear maintenance or only gear construction.

"Because items such as fishing boats and fishing gear are used for several years, their lifetimes were assigned values of 30 years and 3 years, respectively."

So, usage over a year was assigned:
1667 kg nets
1667 kg trawl line
1667 kg ground rope
333 pieces net float
6.7 pieces otter board
166.7 pieces weight
333.7 [typo?] kg fishing gear accessory

212 t landed catch for the year [[ what about bycatch? ]]:
  78.7 t brown sole
  20.2 t stone flounder
  13.5 t marbled sole
   8.0 t olive flounder
  91.5 t all others

there is the issue of bycatch... according to Gilman, increase the catch by 36-44%

let's say 300 t catch + bycatch

Omitting weights, otter boards, and accessories, this leads to a gear weight of 5333 kg gear [allocated] divided into 300 t total capture = 56.3 capture *per year of operation* [this still needs to be in there!]
or 0.0178 kg gear*year per kg catch 


322,046 L heavy fuel oil

for this small scale trawl study we can figure most fuel use is during fishing operations [because trawl is fuel intensive and because in this study the fishing grounds are near-shore in a bay

so the fuel use, or maybe 75% or maybe 90% of the fuel use, can be allocated to fishing operations- giving us kwh/t

322046 L heavy fuel oil * 0.75 alloc to fishing time * 10-10.5 kWh/L / 212 t
 = 2.4-2.5 x 10^6 / 300 ==> 8000-8500 kWh/t
 that figure is quite high compared to the industrial / GFW estimates

about 1100 kWh/t corresponds to CHN and RUS GFW stats

well. There are plenty of data points in the vicinity of 8000 kwh/t


