﻿REPORT 
  OF 
  THE 
  COMMISSIONER 
  OF 
  FISHERIES. 
  65 
  

  

  cations 
  embracing 
  the 
  results 
  of 
  this 
  series 
  of 
  investigations 
  have 
  been 
  

   very 
  favorably 
  received 
  by 
  the 
  pcarl-mnssel 
  mterests, 
  and 
  in 
  some 
  

   cases 
  have 
  opened 
  new 
  fields 
  to 
  mdustry. 
  In 
  connection 
  with 
  these 
  

   studies 
  and 
  the 
  deductions 
  based 
  on 
  them, 
  the 
  question 
  of 
  the 
  pro- 
  

   tection 
  of 
  the 
  mussel 
  fisheries 
  has 
  received 
  critical 
  attention, 
  and 
  a 
  

   report 
  on 
  constructive 
  and 
  conservative 
  legislation 
  has 
  been 
  issued 
  

   and 
  brought 
  to 
  the 
  attention 
  of 
  the 
  authorities 
  of 
  the 
  States 
  having 
  

   mussel 
  resources. 
  

  

  Of 
  interest 
  to 
  fish 
  culturists 
  are 
  the 
  experiments 
  being 
  conducted 
  

   at 
  Homer, 
  Minn., 
  to 
  determine 
  the 
  feasibility 
  of 
  propagatmg 
  amphi- 
  

   pods, 
  or 
  water 
  fleas, 
  in 
  sufficient 
  quantities 
  to 
  be 
  economically 
  avail- 
  

   able 
  as 
  food 
  for 
  young 
  fish, 
  of 
  which 
  they 
  constitute 
  a 
  natural 
  diet. 
  

  

  The 
  study 
  of 
  the 
  salmons 
  of 
  the 
  Pacific 
  coast 
  has 
  been 
  continued, 
  

   and 
  in 
  June, 
  1914, 
  a 
  temporary 
  assistant 
  was 
  employed 
  to 
  take 
  up 
  

   systematically 
  an 
  mquiry 
  into 
  the 
  life 
  history 
  of 
  the 
  species 
  of 
  the 
  

   Sacramento 
  and 
  Columbia 
  Rivers 
  mainly 
  through 
  the 
  study 
  of 
  the 
  

   scales, 
  the 
  new 
  means 
  which 
  science 
  has 
  placed 
  at 
  the 
  disposal 
  of 
  such 
  

   inquhies. 
  

  

  FRESH-WATER 
  MUSSEL 
  CULTURE. 
  

  

  The 
  propagation 
  of 
  fresh-water 
  pearly 
  mussels, 
  which 
  is 
  a 
  recent 
  

   development 
  of 
  the 
  Bureau's 
  work, 
  already 
  has 
  assumed 
  important 
  

   proportions. 
  In 
  this 
  the 
  second 
  year 
  of 
  its 
  active 
  prosecution, 
  227,- 
  

   536,814 
  glochidia 
  or 
  larval 
  mussels 
  were 
  planted, 
  an 
  increase 
  of 
  50 
  

   per 
  cent 
  over 
  the 
  output 
  of 
  the 
  preceding 
  year. 
  Of 
  these 
  86,026,000 
  

   were 
  planted 
  m 
  the 
  Mississippi 
  River 
  in 
  the 
  vicinity 
  of 
  Fahport, 
  Iowa; 
  

   7,316,000 
  m 
  the 
  same 
  stream 
  near 
  La 
  Crosse,' 
  Wis.; 
  101,136,200 
  in 
  

   Lake 
  Pepin, 
  Minn.; 
  8,840,000 
  in 
  Black 
  River, 
  Ark.; 
  4,726,000 
  in 
  

   White 
  River, 
  Ark.; 
  and 
  19,258,000 
  m 
  Wabash 
  River, 
  Ind., 
  in 
  addi- 
  

   tion 
  to 
  which 
  smaller 
  experimental 
  plants 
  were 
  made 
  in 
  Grand 
  River, 
  

   Mich.; 
  I^ake 
  Pokegama, 
  Minn.; 
  and 
  Maumee 
  River, 
  Ind. 
  

  

  As 
  is 
  now 
  generally 
  known, 
  these 
  larval 
  mussels 
  are 
  parasitic 
  on 
  

   fishes, 
  and 
  to 
  carry 
  the 
  number 
  of 
  glochidia 
  mdicated 
  167,819 
  fishes 
  

   were 
  mfected 
  and 
  liberated 
  in 
  the 
  streams. 
  Of 
  this 
  number 
  66,645 
  

   were 
  rescued 
  from 
  the 
  overflowed 
  lands, 
  where 
  they 
  would 
  otherwise 
  

   have 
  perished, 
  and 
  as 
  these 
  were 
  all 
  adults, 
  and 
  in 
  most 
  cases 
  valuable 
  

   species, 
  this 
  number 
  of 
  breeding 
  fishes 
  was 
  incidentally 
  saved 
  for 
  the 
  

   maintenance 
  of 
  the 
  food 
  supply 
  of 
  the 
  streams 
  in 
  which 
  they 
  were 
  

   placed. 
  This 
  in 
  itself 
  would 
  almost 
  warrant 
  the 
  expenditure 
  in- 
  

   curred, 
  but 
  disregarding 
  it, 
  and 
  charging 
  all 
  expenses 
  to 
  mussel 
  cul- 
  

   ture 
  alone, 
  the 
  cost 
  of 
  the 
  glochidia 
  phxnted 
  in 
  the 
  streams 
  was 
  4.3 
  

   cents 
  per 
  thousand, 
  as 
  compared 
  with 
  7 
  cents 
  in 
  the 
  preceding 
  year. 
  

   This 
  mcludes, 
  in 
  both 
  cases, 
  overhead 
  charges 
  for 
  maintenance 
  and 
  

   depreciation 
  of 
  the 
  plant 
  employed 
  and 
  supervision 
  of 
  the 
  work. 
  

   These 
  statistics 
  are 
  presented, 
  not 
  to 
  show 
  the 
  value 
  of 
  mussel 
  culture, 
  

   but 
  to 
  indicate 
  that 
  it 
  is 
  bemg 
  conducted 
  on 
  such 
  scale 
  and 
  with 
  such 
  

   efficiency 
  as 
  will 
  measure 
  its 
  utility 
  in 
  due 
  time. 
  

  

  Those 
  engaged 
  in 
  the 
  fishery 
  aheady 
  report 
  an 
  increase 
  in 
  the 
  abun- 
  

   dance 
  of 
  young 
  mussels 
  on 
  the 
  beds, 
  and 
  they 
  attribute 
  the 
  fact 
  to 
  

   the 
  Bureau's 
  operations, 
  but 
  those 
  m 
  charge 
  of 
  the 
  work 
  believe 
  that 
  

   it 
  will 
  be 
  several 
  years 
  at 
  least 
  before 
  conclusive 
  evidence 
  of 
  the 
  bene- 
  

   fits 
  wiU 
  be 
  available. 
  It 
  should 
  be 
  remembered, 
  moreover, 
  that 
  

   while 
  the 
  larval 
  mussels 
  are 
  planted 
  in 
  more 
  or 
  less 
  circurnscribed 
  

   localities 
  in 
  the 
  Mississippi 
  River 
  system, 
  the 
  fact 
  that 
  they 
  are 
  car- 
  

  

  