﻿86 
  REPORT 
  OF 
  COMMISSIONER 
  OF 
  FISH 
  AKD 
  FISHERIES. 
  

  

  COMMERCIAL 
  SPONGES 
  OF 
  FLORIDA. 
  

  

  Survey 
  of 
  the 
  spo7ige 
  grounds. 
  — 
  The 
  steamer 
  i^«sA 
  Hawk 
  continued 
  

   the 
  survey 
  of 
  the 
  sponge 
  grounds 
  off 
  the 
  Florida 
  coast, 
  beginning 
  

   work 
  at 
  Cape 
  Sable 
  on 
  December 
  17, 
  and 
  concluding 
  in 
  the 
  vicinity 
  of 
  

   Cape 
  Florida 
  about 
  the 
  end 
  of 
  February. 
  During 
  this 
  period 
  all 
  the 
  

   sponge 
  grounds 
  of 
  the 
  east 
  coast 
  were 
  examined 
  and 
  plotted, 
  thus 
  con- 
  

   cluding 
  the 
  survey 
  of 
  the 
  sponge-bearing 
  bottoms 
  of 
  the 
  state 
  begun 
  

   several 
  years 
  ago. 
  Complete 
  collections 
  of 
  sponges 
  were 
  made, 
  and 
  

   much 
  information 
  was 
  acquired 
  in 
  regard 
  to 
  the 
  productivity 
  of 
  the 
  

   sponge 
  grounds, 
  the 
  comparative 
  abundance 
  of 
  the 
  different 
  kinds 
  of 
  

   sponges 
  on 
  the 
  various 
  grounds, 
  etc. 
  Experiments 
  were 
  undertaken 
  

   to 
  test 
  the 
  feasibility 
  of 
  transporting 
  sponges 
  alive 
  in 
  aquaria 
  on 
  the 
  

   ship, 
  but 
  without 
  marked 
  success. 
  During 
  the 
  course 
  of 
  the 
  survey 
  

   lines 
  of 
  dredgings 
  and 
  soundings 
  were 
  run 
  at 
  right 
  angles 
  to 
  the 
  coast, 
  

   in 
  order 
  to 
  determine 
  the 
  general 
  character 
  of 
  the 
  bottom 
  fauna 
  on 
  the 
  

   inner 
  edge 
  of 
  the 
  Gulf 
  Stream, 
  and 
  considerable 
  collections 
  of 
  valuable 
  

   material 
  were 
  made. 
  

  

  Sponge 
  culture. 
  — 
  During 
  the 
  3^ear 
  the 
  experiments 
  in 
  sponge 
  culture 
  

   have 
  been 
  continued 
  under 
  the 
  direction 
  of 
  Dr. 
  H. 
  F. 
  Moore, 
  at 
  three 
  

   different 
  points 
  on 
  the 
  coast 
  of 
  Florida, 
  Practically 
  the 
  same 
  methods 
  

   have 
  been 
  followed 
  as 
  during 
  the 
  preceding 
  year, 
  but 
  additional 
  

   materials 
  for 
  attachment 
  have 
  been 
  tried 
  in 
  order 
  to 
  determine 
  the 
  

   cheapest 
  and 
  most 
  durable. 
  As 
  stated 
  in 
  previous 
  reports, 
  the 
  method 
  

   which 
  appears 
  to 
  give 
  the 
  best 
  results, 
  having 
  due 
  regard 
  for 
  the 
  

   requirements 
  of 
  a 
  commercially 
  profitable 
  industry, 
  is 
  the 
  attachment 
  

   of 
  the 
  cuttings 
  to 
  wires 
  fastened 
  to 
  stakes 
  driven 
  into 
  the 
  bottom 
  

   about 
  50 
  feet 
  apart, 
  in 
  such 
  manner 
  that 
  they 
  are 
  suspended 
  free 
  of 
  

   the 
  bottom. 
  It 
  has 
  been 
  determined 
  that 
  the 
  cuttings 
  not 
  only 
  grow 
  

   more 
  rapidly 
  and 
  of 
  more 
  regular 
  shape 
  when 
  suspended 
  freely 
  in 
  the 
  

   water, 
  but 
  that 
  a 
  larger 
  proportion 
  survive. 
  Numerous 
  parallel 
  experi- 
  

   ments, 
  where 
  the 
  free 
  suspension 
  of 
  the 
  cuttings 
  in 
  one 
  case 
  was 
  the 
  

   only 
  difference 
  in 
  the 
  conditions, 
  show 
  indubitably 
  the 
  advantage 
  of 
  

   raising 
  the 
  wires 
  above 
  the 
  bottom. 
  When 
  the 
  cuttings 
  are 
  not 
  sus- 
  

   pended, 
  wave 
  movements 
  produce 
  attrition 
  upon 
  the 
  bottom 
  and 
  sub- 
  

   sequent 
  abrasion 
  of 
  the 
  surface 
  of 
  the 
  sponge, 
  and 
  the 
  mortality 
  rate 
  

   is 
  high, 
  especially 
  during 
  the 
  early 
  stages 
  of 
  growth. 
  

  

  The 
  deposit 
  of 
  silt 
  and 
  the 
  overgrowth 
  of 
  vegetable 
  matter 
  in 
  por- 
  

   tions 
  of 
  the 
  sponge 
  also 
  restrict 
  the 
  growth, 
  causing 
  not 
  only 
  a 
  reduc- 
  

   tion 
  in 
  weight, 
  but 
  an 
  irregularity 
  of 
  form 
  which 
  reduces 
  the 
  market 
  

   value. 
  When 
  the 
  cuttings 
  are 
  suspended 
  the 
  ultimate 
  shape, 
  whatever 
  

   be 
  the 
  original 
  shape 
  of 
  the 
  cutting, 
  is 
  invariably 
  regularly 
  spherical 
  

   or 
  ellipsoidal. 
  From 
  a 
  commercial 
  standpoint 
  the 
  method 
  is 
  mani- 
  

   festly 
  an 
  improvement 
  upon 
  nature's, 
  for 
  the 
  suspended 
  sponge 
  is 
  

   more 
  advantageously 
  situated 
  as 
  regards 
  water 
  currents 
  and 
  food 
  sup- 
  

  

  