﻿THE 
  HERRING 
  FISHERIES 
  OF 
  THE 
  NORTHEAST 
  COAST. 
  409 
  

  

  On 
  the 
  coast 
  of 
  ISTorway 
  the 
  spawning 
  season 
  is 
  about 
  the 
  same 
  as 
  in 
  

   Scotland, 
  but 
  on 
  the 
  coast 
  of 
  BohuslJin 
  the 
  bulk 
  of 
  the 
  spring 
  spawning 
  

   is 
  in 
  April, 
  though 
  to 
  some 
  extent 
  it 
  occurs 
  also 
  in 
  March 
  and 
  ]\Iay, 
  

   thus 
  more 
  nearly 
  corresponding 
  to 
  the 
  season 
  in 
  the 
  P.ay 
  of 
  Fiindy. 
  

   The 
  isothermal 
  lines 
  extend 
  parallel 
  to 
  the 
  coast 
  of 
  Korway 
  and 
  thence 
  

   across 
  the 
  Korth 
  Sea 
  to 
  Scotland, 
  which 
  means 
  that 
  the 
  waters 
  on 
  the 
  

   two 
  coasts 
  have 
  practically 
  the 
  same 
  temperature, 
  while 
  the 
  spring 
  

   fisheries 
  of 
  Bohusliin 
  are 
  no 
  doubt 
  influenced 
  by 
  the 
  discharge 
  of 
  cold 
  

   water 
  from 
  the 
  Baltic, 
  which 
  is 
  frozen 
  during 
  the 
  winter. 
  The 
  later 
  

   occurrence 
  of 
  our 
  spring 
  fisheries 
  is 
  probably 
  connected 
  with 
  the 
  lower 
  

   temperature 
  of 
  the 
  waters 
  on 
  our 
  coast 
  in 
  early 
  spring, 
  owing 
  to 
  the 
  

   influence 
  of 
  the 
  Arctic 
  current 
  flowing 
  southward 
  between 
  the 
  coast 
  

   and 
  the 
  Gulf 
  Stream. 
  The 
  effect 
  of 
  this 
  is 
  to 
  produce 
  a 
  sharp 
  southerly 
  

   deflection 
  of 
  both 
  summer 
  and 
  winter 
  isothermal 
  lines, 
  so 
  that 
  they 
  

   reach 
  the 
  coast 
  in 
  a 
  much 
  lower 
  latitude 
  on 
  the 
  western 
  than 
  on 
  the 
  

   eastern 
  shore 
  of 
  the 
  Atlantic. 
  

  

  There 
  are 
  no 
  records 
  available 
  which 
  will 
  show 
  the 
  temperatures 
  upon 
  

   the 
  spring 
  spawning-grounds, 
  but 
  it 
  is 
  probable 
  that 
  owing 
  to 
  the 
  strong 
  

   tidal 
  circulation 
  the 
  temperature 
  in 
  Oak 
  Bay 
  does 
  not 
  difler 
  much 
  from 
  

   that 
  at 
  Eastport, 
  where 
  ten 
  years' 
  observation 
  shows 
  that 
  a 
  mean 
  bottom 
  

   temperature 
  of 
  40° 
  F. 
  is 
  not 
  reached 
  before 
  the 
  middle 
  of 
  May. 
  The 
  

   minimum 
  temperature 
  for 
  the 
  year, 
  about 
  31° 
  F., 
  was 
  observed 
  during 
  

   March, 
  the 
  mean 
  for 
  that 
  month 
  being 
  about 
  33.4° 
  F. 
  After 
  March 
  the 
  

   temperature 
  gradually 
  rises 
  until 
  it 
  reaches 
  the 
  maximum 
  of 
  52.8° 
  F. 
  

   in 
  September, 
  the 
  mean 
  of 
  ten 
  years 
  observation 
  being 
  50.4° 
  F. 
  

  

  The 
  following 
  table 
  gives 
  a 
  record 
  of 
  the 
  mean 
  temperatures 
  of 
  the 
  

   air 
  and 
  water 
  at 
  Eastport, 
  Me., 
  for 
  ten-day 
  periods 
  from 
  1878 
  to 
  1887, 
  

   inclusive. 
  The 
  observations 
  were 
  made 
  by 
  the 
  Signal 
  Service, 
  United 
  

   Sta?tes 
  Army, 
  daily 
  between 
  the 
  hours 
  of 
  1 
  ]). 
  m. 
  and 
  3 
  p. 
  m. 
  

  

  Date. 
  

  

  1878-1887. 
  

   Jan. 
  10 
  

  

  20 
  

  

  30 
  

  

  Feb. 
  9 
  

  

  19 
  

  

  Mar. 
  1 
  

  

  11 
  

  

  21 
  

  

  31 
  

  

  Apr. 
  10 
  

  

  20 
  

  

  30 
  

  

  May 
  10 
  

  

  20 
  

  

  30 
  

  

  June 
  9 
  

  

  19 
  

  

  29 
  

  

  o 
  p^ 
  

  

  23.52 
  

  

  23.13 
  

  

  22.99 
  

  

  23. 
  28 
  

  

  27.09 
  

  

  20. 
  .52 
  

  

  28.71 
  

  

  32. 
  24 
  

  

  34.71 
  

  

  38.64 
  

  

  43.47 
  

  

  47.25 
  

  

  49.81 
  

  

  51.92 
  

  

  54.38 
  

  

  57. 
  42 
  

  

  59.47 
  

  

  63.86 
  

  

  Surface. 
  

  

  ° 
  F. 
  

  

  38. 
  03 
  

  

  36.89 
  

  

  36.04 
  

  

  34.57 
  

  

  34.20 
  

  

  33. 
  47 
  

   33.39 
  

   33.72 
  

  

  34. 
  :<7 
  

  

  35. 
  28 
  

   36.49 
  

   37.96 
  

   38.69 
  

   40. 
  U3 
  

   41.01 
  

   42.40 
  

   43. 
  86 
  

   45.35 
  

  

  Bottom- 
  

   depth 
  

   2 
  to 
  32 
  

  

  feet. 
  

  

  o 
  jP. 
  

  

  38.02 
  

  

  36.83 
  

  

  35.89 
  

  

  34.40 
  

  

  34.01 
  

  

  33.34 
  

  

  33.12 
  

  

  33.32 
  

  

  33.82 
  

  

  34.58 
  

  

  35.67 
  

  

  37.04 
  

  

  37.93 
  

  

  ■'(9. 
  HI 
  

  

  40.19 
  

  

  41.34 
  

  

  43.05 
  

  

  44.42 
  

  

  Date. 
  

  

  1878-1887, 
  

   July 
  9.... 
  

  

  19 
  

  

  29 
  

  

  Aug. 
  8 
  

  

  18 
  

  

  28 
  

  

  Sept. 
  7 
  

  

  17 
  

  

  27 
  

  

  Oct 
  7 
  

  

  17 
  

  

  27 
  

  

  Nov. 
  8 
  

  

  16 
  

  

  26 
  

  

  Dec. 
  6 
  

  

  16 
  

  

  31 
  

  

  Bottom- 
  

   depth 
  

   2 
  to 
  32 
  

   feet. 
  

  

  o 
  F. 
  

  

  45.87 
  

  

  46.92 
  

  

  47.75 
  

  

  48.65 
  

  

  49.53 
  

  

  50.12 
  

  

  50.34 
  

  

  50.63 
  

  

  50. 
  33 
  

  

  50. 
  36 
  

  

  49.88 
  

  

  48.96 
  

  

  47.80 
  

  

  46.59 
  

  

  45. 
  35 
  

  

  43.69 
  

  

  42. 
  18 
  

  

  39.77 
  

  

  The 
  extremes 
  in 
  the 
  water 
  temperatures 
  during 
  the 
  ten 
  years 
  did 
  not 
  

   difler 
  in 
  any 
  given 
  ten-day 
  period 
  to 
  a 
  greater 
  extent 
  than 
  5°, 
  and 
  the 
  

   difference 
  was 
  generally 
  less 
  than 
  3°. 
  

  

  