﻿OTTER-TRAWL 
  FISHERY. 
  63 
  

  

  and 
  that 
  round 
  fishes 
  and 
  flat 
  fishes 
  each 
  followed 
  the 
  same 
  general 
  

   trend. 
  From 
  1903 
  to 
  1906 
  and 
  again 
  from 
  1906 
  to 
  1912 
  steam 
  trawl- 
  

   caught 
  demersal 
  fishes 
  as 
  a 
  whole, 
  as 
  well 
  as 
  both 
  round 
  fishes 
  and 
  

   flat 
  fishes, 
  showed 
  heavy 
  decreases, 
  the 
  total 
  percentile 
  falling 
  off 
  

   in 
  the 
  flat 
  fishes 
  being 
  the 
  greatest. 
  

  

  Steam 
  trawl-caught 
  cod 
  gained 
  in 
  total 
  catch 
  from 
  1891 
  to 
  1898 
  

   and 
  from 
  1898 
  to 
  1901 
  but 
  exhibited 
  a 
  falling 
  off 
  of 
  about 
  3 
  per 
  cent 
  

   from 
  1903 
  to 
  1906. 
  From 
  1906 
  to 
  1912, 
  however, 
  there 
  was 
  a 
  mate- 
  

   rial 
  increase, 
  and 
  it 
  is 
  apparent 
  that 
  the 
  total 
  catch 
  of 
  the 
  species 
  by 
  

   trawlers 
  increased 
  more 
  or 
  less 
  continuously 
  from 
  1891 
  to 
  1912, 
  

   Steam 
  trawl-caught 
  haddock 
  on 
  the 
  contrary 
  declined 
  in 
  total 
  

   throughout 
  the 
  entire 
  time, 
  and 
  in 
  the 
  two 
  periods, 
  from 
  1891 
  to 
  

   1901, 
  and 
  from 
  1903 
  to 
  1912, 
  the 
  decreases 
  amounted 
  to 
  33 
  per 
  cent 
  

   and 
  44 
  per 
  cent, 
  respectively. 
  In 
  the 
  case 
  of 
  the 
  plaice 
  there 
  was 
  an 
  

   increase 
  in 
  the 
  catch 
  between 
  both 
  1891 
  and 
  1898 
  and 
  1898 
  and 
  1901, 
  

   the 
  aggregate 
  of 
  the 
  two 
  amounting 
  to 
  35 
  per 
  cent 
  of 
  the 
  catch 
  of 
  

   1891. 
  In 
  both 
  1906 
  and 
  1912 
  the 
  catch 
  was 
  much 
  less 
  than 
  in 
  1913, 
  

   and 
  the 
  decrease 
  in 
  the 
  entire 
  period 
  was 
  nearly 
  53 
  per 
  cent. 
  For 
  the 
  

   entire 
  term 
  from 
  1891 
  to 
  1912 
  there 
  was, 
  therefore, 
  an 
  increase 
  in 
  the 
  

   total 
  catch 
  of 
  cod 
  by 
  steam 
  trawlers 
  and 
  a 
  decrease 
  in 
  the 
  catches 
  

   of 
  haddock 
  and 
  plaice, 
  especially 
  the 
  former. 
  

  

  The 
  foregoing 
  discussion 
  is 
  concerned 
  with 
  the 
  total 
  catches 
  of 
  the 
  

   several 
  classes, 
  categories, 
  and 
  kinds 
  of 
  fishes; 
  but 
  while 
  the 
  indi- 
  

   cated 
  changes 
  were 
  taking 
  place 
  there 
  were 
  synchronous 
  but 
  not 
  

   necessarily 
  parallel 
  changes 
  in 
  the 
  composition 
  and 
  fishing 
  power 
  of 
  

   the 
  fleet 
  and 
  variations 
  in 
  the 
  intensity 
  of 
  the 
  fishery 
  conducted 
  by 
  

   it. 
  To 
  eliminate 
  these 
  variables 
  as 
  far 
  as 
  possible 
  the 
  catch 
  may 
  be 
  

   reduced 
  to 
  the 
  average 
  per 
  vessel, 
  the 
  average 
  per 
  voyage, 
  or 
  the 
  

   average 
  per 
  day's 
  absence 
  from 
  port. 
  The 
  first 
  is 
  objectionable 
  in 
  

   that 
  it 
  does 
  not 
  eliminate 
  the 
  effects 
  of 
  variations 
  in 
  the 
  number 
  of 
  

   vessels 
  tied 
  up 
  for 
  variable 
  and 
  undeterminable 
  periods, 
  and 
  we 
  have, 
  

   therefore, 
  confined 
  ourselves 
  to 
  the 
  consideration 
  of 
  the 
  other 
  two. 
  

  

  Unfortunately 
  these 
  methods 
  of 
  analysis 
  can 
  not 
  be 
  applied 
  at 
  all 
  

   prior 
  to 
  1903, 
  as 
  the 
  data 
  are 
  not 
  furnished 
  in 
  the 
  reports, 
  and 
  for 
  

   1903 
  and 
  the 
  following 
  years 
  the 
  average 
  catch 
  per 
  day's 
  absence 
  is 
  

   stated 
  for 
  a 
  part 
  only 
  of 
  the 
  total 
  catch 
  (that 
  not 
  landed 
  in 
  London 
  

   where 
  most 
  of 
  the 
  fish 
  are 
  brought 
  in 
  by 
  carriers 
  and 
  not 
  by 
  the 
  

   fishermen). 
  The 
  catch 
  per 
  voyage 
  is 
  not 
  given 
  at 
  all, 
  although 
  the 
  

   average 
  duration 
  of 
  the 
  voyages 
  is 
  given 
  for 
  all 
  ports 
  excluding 
  

   London. 
  

  

  As 
  this 
  information 
  applies 
  to 
  the 
  major 
  portion 
  of 
  the 
  fishing 
  

   operations, 
  it 
  may 
  be 
  assumed 
  that 
  it 
  is 
  reasonably 
  applicable 
  to 
  all. 
  

  

  