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METHODS         30     Methods   BENTHIC  ASSESSMENTS   The  University  of  the  Virgin  Islands  determined  the  benthic  composition  at  33  long-­‐term   monitoring  sites  between  2001  and  2012  (Fig.  4).    Around  St.  Croix  the  following  14  sites   were  assessed:  Buck  Island-­‐St.  Croix,  Cane  Bay,  Cane  Bay  Deep,  Castle,  Eagle  Ray,  Great   Pond,  Jacks/Isaacs  Bay,  Kings  Corner,  Lang  Bank  East  End  Marine  Park  (Lang  EEMP),   Lang  Bank  Red  Hind  Fish  Spawning  Aggregation  (Lang  Hind),  Mutton  Snapper,  Salt  River,   Salt  River  Deep,  and  Sprat  Hole.    Four  of  these  sites  are  within  the  St.  Croix  East  End   Marine  Park  boundary  (Castle,  Great  Pond,  Jacks  Bay,  Lang  EEMP),  three  sites  are  within   National  Park  Service  boundaries  (Buck  Island-­‐St.  Croix,  Salt  River  West  ,  and  Salt  River   Deep),  two  sites  are  within  federal  fisheries  marine  protected  areas  (Lang  Hind,  Mutton   Snapper),  and  four  sites  can  be  considered  mesophotic  coral  reefs  (Cane  Bay  Deep,  Lang   Bank  EEMP,  Lang  Hind  FSA,  Salt  River  Deep;  sensu  Ginsburg  2007)  (Ginsburg   METHODS     31   2007)(Ginsburg  2007).  Salt  River  Deep  transects  1-­‐4  were  moved  from  40  m  depth  at  the   April  2009  sampling  to  30  m  in  the  January  2010  sampling  due  to  low  coral  cover  in  the   deeper  transects.     Around  St.  John-­‐St.  Thomas  the  following  19  sites  were  assessed:  Black  Point,  Botany  Bay,   Brewers  Bay,  Buck  Island-­‐St.  Thomas,  Coculus  Rock,  College  Shoal  East,  Coral  Bay,  Fish   Bay,  Flat  Cay,  Ginsburgs  Fringe,  Grammanik  Tiger  FSA,  Hind  Bank  FSA,  Little  St.  James,   Magens  Bay,  Savana  Island,  Seahorse  Cottage  Shoal  (Seahorse),  Meri  Shoal,  South  Capella,   and  South  Water  Island.  One  site  is  the  within  the  St.  Thomas  East  End  Reserve  (Coculus   Rock),  four  sites  are  within  federal  fisheries  marine  protected  areas  (College  Shoal,   Ginsburgs  Fringe,  Grammanik  Tiger,  Hind  Bank),  and  five  sites  can  be  considered   mesophotic  coral  reefs  (College  Shoal,  Ginsburgs  Fringe,  Grammanik  Tiger,  Hind  Bank,   Meri  Shoal).    Four  sites  are  also  part  of  the  Ciguatera  Fish  Monitoring  Program  and  have   been  surveyed  monthly  for  benthic  structure  and  coral  health  since  2010  (Black  Point,   Coculus  Rock,  Flat  Cay,  Seahorse).   Benthic  Cover.  At  each  site  benthic  cover  and  coral  health  surveys  were  conducted  along   six  10  m  long  permanent  transects  marked  with  steel  or  brass  rods.    Video  sampling   consisted  of  one  diver  traversing  each  transect  videotaping  the  benthic  cover  using  a  high   definition  video  cassette  recorder  (Sony  FX-­‐7  in  Light  and  Motion  housing)  or  an  HD   digital  video  recorder  with  wide  angle  lens  (Canon  XF  in  Light  and  Motion  housing).    The   diver  swam  at  a  uniform  speed,  pointing  the  camera  down  and  keeping  the  lens   approximately  0.4  m  above  the  substrate  at  all  times.    A  guide  wand  or  dropper  weight   attached  to  the  camera  housing  was  used  to  help  the  diver  maintain  the  camera  a   constant  distance  above  the  reef.    After  taping,  approximately  20  -­‐  50  non-­‐overlapping   images  per  transect  were  captured  and  saved  as  JPEG  files  (Fig.  5).    Captured  images   represented  an  area  of  reef  approximately  0.31  m2  (0.64  m  x  0.48  m).    Coral  Point  Count   with  Excel  Extension  software  (Kohler  and  Gil  2006)  was  used  to  superimpose  ten   METHODS         32     randomly  located  dots  on  each  image.    The  substrate  type  located  under  each  of  the  dots   was  then  identified  to  the  most  descriptive  level  possible  and  entered  into  a  database.     Where  multiple  benthic  cover  categories  fell  under  a  single  point,  for  example   macroalgae  over  bedrock,  the  upper  benthic  category  was  assessed.    For  each  transect,   the  percent  cover  of  coral,  epilithic  algae  (formerly  called  dead  coral  with  turf  algae),   macroalgae,  sponges,  gorgonians,  and  sand/sediment  were  calculated  by  dividing  the   number  of  random  dots  falling  on  that  substrate  type  by  the  total  number  of  dots  for  that   transect.    Epilithic  algae  (sensu  Hatcher  and  Larkum  1983)  are  diminutive  turfs  and   filamentous  algae  without  thallus  structure  that  cover  all  rock  surfaces  of  coral  reefs  not   occupied  by  larger  epibenthic  organisms.    They  can  also  be  considered  to  be  grazed   surfaces  are  often  an  indicator  of  healthy  grazing  communities  and  high  animal  cover.     Figure  5.    A  screen  grab  of  benthic  video  used  for  the  determination  of  percent  cover  of  coral  reef   organisms  and  non-­‐living  substrate.     METHODS     33   Table  1.    TCRMP  site  reef  complex  type,  location  coordinates,  and  depths.    FSA  =  Fish  Spawning   Aggregation.    EEMP  =  East  End  Marine  Park.       Island Site Reef Complex Lat Long Depth (m) St. Croix Buck Island-St. Croix Offshore-Shallow 17.78500 -64.60917 15 Cane Bay Nearshore 17.77388 -64.81350 10 Cane Bay Deep Offshore-MCE 17.77661 -64.81522 38 Castle Offshore-Shallow 17.76278 -64.59743 7 Eagle Ray Offshore-Shallow 17.76150 -64.69880 10 Great Pond Nearshore 17.71097 -64.65221 6 Jacks Bay Nearshore 17.74337 -64.57160 14 Kings Corner Nearshore 17.69116 -64.90008 17 Lang Bank EEMP Offshore-MCE 17.72145 -64.54706 27 Lang Bank Red Hind FSA Offshore-MCE 17.82372 -64.44943 33 Mutton Snapper FSA Offshore-Shallow 17.63660 -64.86240 24 Salt River Deep Offshore-MCE 17.78523 -64.75917 30 Salt River West Offshore-Shallow 17.78530 -64.75940 11 Sprat Hole Nearshore 17.73400 -64.89540 8 St. John Coral Bay Nearshore-Shallow 18.33797 -64.70402 9 Fish Bay Nearshore 18.31417 -64.76408 6 Meri Shoal Offshore-MCE 18.24433 -64.75832 30 St. Thomas Black Point Nearshore 18.34450 -64.98595 9 Botany Bay Nearshore 18.35845 -65.03330 8 Brewers Bay Nearshore 18.34403 -64.98435 6 Buck Island-St. Thomas Offshore-Shallow 18.27883 -64.89833 14 Coculus Rock Nearshore 18.31257 -64.86058 7 College Shoal East Offshore-MCE 18.18568 -65.07677 30 Flat Cay Offshore-Shallow 18.31822 -64.99104 12 Ginsburgs Fringe Offshore-MCE 18.18770 -64.95998 63 Grammanik Tiger FSA Offshore-MCE 18.19113 -64.95032 38 Hind Bank East FSA Offshore-MCE 18.20217 -65.00158 39 Magens Bay Nearshore 18.37425 -64.93438 7 Savana Offshore-Shallow 18.34064 -65.08205 9 Seahorse Cottage Shoal Offshore-Shallow 18.29467 -64.86750 20 South Capella Offshore-Shallow 18.26267 -64.87237 20 South Water Offshore-Shallow 18.28068 -64.94592 20 St James Offshore-Shallow 18.29459 -64.83238 15 METHODS         34     Table  2.    TCRMP  site  date  sampled  (benthic/health)  and  type  of  sampling.     Island Site Date Sampled Benthic Health Fish/Urchin St. Croix Buck Island STX 8/13/12 x x x Cane Bay 8/12/12 x x x Cane Bay Deep 8/12/12 x x x Castle 8/15/12 x x x Eagle Ray 8/17/12 x x x Great Pond 8/14/12 x x x Jacks Bay 8/13/12 x x x Kings Corner 8/16/12 x x x Lang Bank EEMP 8/14/12 x x x Lang Bank Red Hind FSA 8/15/12 x x x Mutton Snapper FSA 8/17/12 x x x Salt River Deep 8/11/12 x x x Salt River West 8/11/12 x x x Sprat Hole 8/16/12 x x x St. John Coral Bay 12/03/12 x x x Fish Bay 10/11/12 x x x Meri Shoal 12/03/12 x x x St. Thomas Black Point 10/25/12 x x x Botany Bay 11/19/12 x x x Brewers Bay 11/30/12 x x x Buck Island STT 12/16/12 x x x Coculus Rock 10/31/12 x x x College Shoal East 10/04/12 x x x Flat Cay 10/25/12 x x x Ginsburgs Fringe 02/21/13 x Grammanik Tiger FSA 10/09/12 x x x Hind Bank East FSA 11/06/12 x x x Magens Bay 11/19/12 x x x Savana 11/19/12 x x x Seahorse Cottage Shoal 10/31/12 x x x South Capella 12/16/12 x x x South Water 10/02/12 x x x St James 11/30/12 x x x       METHODS     35   Coral  Health.  Coral  health  assessments  follow  methodologies  outlined  in  (Calnan  et  al.   2008)  and  (Smith  et  al.  2008)  and  are  briefly  described  here.  All  coral  colonies  located   directly  under  the  transect  lines  were  assessed  in  situ  for  signs  of  mortality  and  disease   following  a  modified  Atlantic  and  Gulf  Rapid  Reef  Assessment  protocol  (Kramer  et  al.   2005).    In  contrast  to  previous  years  where  only  colonies  greater  than  10  cm  in  maximum   linear  dimension  were  assessed,  starting  in  2008  all  colonies  were  assessed,  regardless  of   size.    Partial  mortality  of  coral  colonies  was  broken  into  two  categories.  Recent  partial   mortality  was  characterized  visually  as  skeleton  not  eroded  (fine  corallite  structure  still   intact)  and  bare  or  with  a  thin  veneer  of  sheeting  or  filamentous  algae.  Recent  partial   mortality  is  typically  visible  for  up  to  three  months  following  tissue  loss.  Old  partial   mortality  was  characterized  as  skeleton  eroded  and  covered  with  turf  or  macroalgae.    Old   partial  mortality  is  a  transition  from  recent  mortality  and  typically  lasts  up  to  1–6  years   (Smith  et  al.  2008,  also  see  http://www.agrra.org/method/methodcor.html).   Diseases  were  conservatively  categorized  into  recognized  Caribbean  scleractinian   diseases  and  syndromes  that  included  bleaching,  black  band  disease,  dark  spots  disease,   white  plague,  and  yellow  band  (blotch)  disease  (following  Bruckner  2007).  Acroporid   corals  were  extremely  rare  at  the  study  sites;  thus,  their  associated  diseases  (white  band   and  white  pox)  are  not  presented.  Bleaching  was  assessed  as  abnormal  paling  of  the   colony,  and,  when  present,  the  severity  of  the  bleaching  (paling  or  total  whitening)  and   the  area  of  the  colony  affected  were  assessed.    A  major  bleaching  event  occurred  between   September  and  December  2005,  affecting  all  monitored  sites,  and  a  mild  bleaching  event   occurred  September  and  October  2010  (Smith  et  al.  2013).    On  St.  Croix,  a  subset  of  sites   were  assessed  during  the  2010  coral  bleaching  event,  and  included  Cane  Bay,  Cane  Bay   Deep,  and  Jacks  Bay.       For  each  transect,  the  prevalence  of  coral  impairment  categories  was  calculated  as  the   number  of  colonies  with  partial  mortality,  disease,  or  bleaching  divided  by  the  number  of   METHODS         36     colonies  assessed.    Also,  for  affected  colonies  in  each  transect  the  average  three-­‐ dimensional  surface  area  (%)  of  the  colony  affected  was  also  estimated  for  each   impairment  category.   FISH  CENSUS   Fish  surveys  were  conducted  at  14  sites  around  St.  Croix  and  18  sites  around  St.  Thomas   (Table  2)  in  2012.    Ten  replicate  belt  transects  and  three  replicate  roving  dive  surveys   (RDS)  were  conducted  at  each  site.  Belt  transects  were  30m  x  4m  and  were  conducted  in   15  min  per  replicate.  All  transects  were  begun  at  a  random  location  on  the  site,  and  were   swum  in  a  random  direction.  RDS  replicates  were  either  30  min  (sites  <  25  m  depth)  or   15  min  (sites  >25  m  depth)  (see  Table  3).  In  addition  to  relative  abundance  data,  specific   total  length  estimates  were  made  for  each  large  grouper,  large  snapper  or  hogfish   (Lachnolaimus  maximus)  encountered.  In  all  surveys,  all  fish  encountered  were  recorded   except  blennies  and  gobies.  Data  were  transcribed  to  Microsoft  Excel  and  Access   spreadsheets,  and  were  analyzed  for  descriptive  statistics  of  reef  fish  assemblage   structure.   Divers  also  counted  the  number  of  Diadema  antillarum  sea  urchins  within  1  m  on  either   side  of  transects.    From  2001  –  2008  this  occurred  along  the  6  –  10  m  long  benthic   transects.    Starting  in  2009,  urchins  were  assessed  along  25x2m  belt  transects   corresponding  to  the  return  of  the  10  fish  transects.    The  mean  number  of  sea  urchins  per   100  m2  was  calculated  for  each  site.     TCRMP  MONITORING  SUMMARY     37   Territorial  Coral  Reef  Monitoring  Summary   BENTHIC  COVER  &  CORAL  HEALTH         38     BENTHIC  COMMUNITIES  AND  CORAL  REEF  HEALTH   Benthic  cover  was  monitored  at  33  monitoring  sites  and  coral  health  was  monitored  at   32  sites  in  2012.    Coral  health  was  not  monitored  at  the  deep  (63m)  Ginsburgs  Fringe.   Benthic  cover  raw  data  is  presented  in  electronic  Appendix  I.    Coral  health  raw  data  is   presented  in  electronic  Appendix  II.   Coral  Cover   The  cover  of  hard  corals  decreased  at  most  sites  after  the  2005  coral  bleaching  event,  but   showed  little  or  no  change  as  the  results  of  the  2010  coral  bleaching  event  (Fig.  6).     Shallow  (<25  m  depth),  nearshore  and  offshore  sites  with  greater  than  about  20%  coral   cover  showed  declines  in  cover,  but  there  was  extreme  variability  in  the  degree  of  cover   change.    For  example  the  Mutton  Snapper  site  on  St.  Croix  lost  87%  of  its  coral  cover   between  2004  and  2006.    Sites  that  had  low  coral  cover  prior  to  2005  lost  far  less  relative   cover  as  the  result  of  bleaching.    While  part  of  this  may  be  due  to  detectability  at  values   nearer  to  0,  these  sites  tend  to  dominated  by  small  massive  species  that  are  more   resistant  to  disease  related  mortality  (Smith  et  al.  2013).   Mesophotic  coral  monitoring  sites  that  were  sampled  before  and  after  the  2005  coral   bleaching  event  showed  slight  relative  losses  of  coral  cover.    Losses  ranged  from  5.4%   (Grammanik  Tiger)  to  36.0%  (Meri  Shoal).    Since  2010,  coral  cover  has  declined  slightly   at  some  mesophotic  sites,  which  may  reflect  the  impact  of  white  diseases  and  a  mild   bleaching  event  that  occurred  in  2012.   Recovery  since  bleaching  was  marginal  at  most  sites.    The  majority  of  sites  had   apparently  level  coral  cover  with  recovery  potentially  inhibited  by  disease  and  increased   interactions  with  other  organisms.    However,  slow  upward  trajectories  are  notable  at   some  sites.   TCRMP  MONITORING  SUMMARY     39     Figure  6.    Coral  cover  (±SE)  across  TCRMP  monitoring  sites  over  time.     Nearshore Cover 0% 20% 40% 60% 80% 100% Black Point Botany Bay Brewers Bay Cane Bay Coculus Rock Coral Bay Fish Bay Great Pond Jacks Bay Kings Corner Magens Bay Salt River West Sprat Hole Offshore Cover 0% 20% 40% 60% 80% 100% Buck Island STT Buck Island STX Castle Eagle Ray Flat Cay Mutton Snapper Savana Island Seahorse South Capella South Water St. James Mesophotic 2001 2002 2003 2004 2005 2005 BL 2006 2007 2008 2009 2010 2011 2012 Cover 0% 20% 40% 60% 80% 100% Cane Bay Deep College Shoal Ginsburgs Fringe Grammanik Tiger Hind Bank FSA Lang Bank EEMP Lang Bank FSA Meri Shoal Salt River Deep BENTHIC  COVER  &  CORAL  HEALTH         40     Epilithic  Algal  Community  Cover   Algae  show  the  highest  inter-­‐annual  variability  of  any  group  of  benthic  organisms  (Fig.   7).    This  is  largely  due  to  seasonality.    The  cover  of  epilithic  algae  is  no  exception,  since  it   tends  to  negatively  covary  with  more  ephemeral  macroalgae.    Epilithic  algae  is  important   as  it  can  indicate  substrates  grazed  by  herbivores  and  therefore  open  to  the  settlement  of   sessile  epibenthic  animals,  including  coral.   Nearshore  and  mesophotic  sites  showed  little  inter-­‐annual  trend  in  epilithic  algal  cover.     Many  offshore  sites,  such  as  Eagle  Ray  and  Buck  Island,  St.  Croix,  appear  to  have  a   declining  abundance  of  epilithic  algae,  indicating  an  increase  in  other  benthic   components,  such  as  macroalgae  and  filamentous  cyanobacteria,  and  possibly  indicating   declining  grazing.   TCRMP  MONITORING  SUMMARY     41     Figure  7.    Epilithic  algal  community  cover  (±SE)  across  TCRMP  monitoring  sites  over  time.   Nearshore Cover 0% 20% 40% 60% 80% 100% Black Point Botany Bay Brewers Bay Cane Bay Coculus Rock Coral Bay Fish Bay Great Pond Jacks Bay Kings Corner Magens Bay Salt River West Sprat Hole Offshore Cover 0% 20% 40% 60% 80% 100% Buck Island STT Buck Island STX Castle Eagle Ray Flat Cay Mutton Snapper Savana Island Seahorse South Capella South Water St. James Mesophotic 2001 2002 2003 2004 2005 2005 BL 2006 2007 2008 2009 2010 2011 2012 Cover 0% 20% 40% 60% 80% 100% Cane Bay Deep College Shoal Ginsburgs Fringe Grammanik Tiger Hind Bank FSA Lang Bank EEMP Lang Bank FSA Meri Shoal Salt River Deep BENTHIC  COVER  &  CORAL  HEALTH         42     Macroalgal  Cover   Macroalgae  have  been  increasing  at  many  reefs,  particularly  after  the  2005  bleaching   event  (Fig.  8).    At  sites  where  there  was  no  loss  of  coral  cover,  increased  macroalgae  may   be  due  to  declining  grazing,  such  as  at  Eagle  Ray.    At  other  sites  where  coral  cover   dropped  after  2005,  space  opened  for  algal  colonization  by  coral  die-­‐off  may  not  have   been  grazed  in  reefs  where  resident  herbivores  communities  are  already  at  the  threshold   of  maximum  grazing  rates  (Williams  et  al.  2001).    These  reefs  include,  the  Buck  Islands   (St.  Thomas  and  St.  Croix),  Cane  Bay,  Meri  Shoal,  South  Capella,  and  Sprat  Hole.    The  same   explanation  may  also  apply  for  filamentous  cyanobacteria  (see  following  section).   TCRMP  MONITORING  SUMMARY     43     Figure  8.    Macroalgae  cover  (±SE)  across  TCRMP  monitoring  sites  over  time.     Nearshore Cover 0% 20% 40% 60% 80% 100% Black Point Botany Bay Brewers Bay Cane Bay Coculus Rock Coral Bay Fish Bay Great Pond Jacks Bay Kings Corner Magens Bay Salt River West Sprat Hole Offshore Cover 0% 20% 40% 60% 80% 100% Buck Island STT Buck Island STX Castle Eagle Ray Flat Cay Mutton Snapper Savana Island Seahorse South Capella South Water St. James Mesophotic 2001 2002 2003 2004 2005 2005 BL 2006 2007 2008 2009 2010 2011 2012 Cover 0% 20% 40% 60% 80% 100% Cane Bay Deep College Shoal Ginsburgs Fringe Grammanik Tiger Hind Bank FSA Lang Bank EEMP Lang Bank FSA Meri Shoal Salt River Deep BENTHIC  COVER  &  CORAL  HEALTH         44     Filamentous  Cyanobacteria   Filamentous  cyanobacteria  cover  has  been  increasing  at  many  sites  in  the  TCRMP  since   the  2005  coral  bleaching  event  (Fig.  9).    This  is  particularly  true  at  many  sites  on  St.  Croix   that  have  attained  very  high  cover  values  in  recent  years.    For  example,  Salt  River  West,   Jacks  Bay,  Cane  Bay,  Sprat  Hole,  Mutton  Snapper,  Buck  Island  (St.  Croix),  Eagle  Ray,  Lang   Bank  EEMP,  and  Lang  Bank  Hind  have  all  seen  cover  of  filamentous  cyanobacteria  from   10  –  60%,  with  2009  as  a  particularly  high  abundance  year  for  offshore  sites.   The  increased  incidence  of  filamentous  cyanobacteria  can  be  an  indication  of   disturbance,  increased  nutrient  inputs,  and  insufficient  grazing  (Fong  and  Paul  2011).    In   addition,  filamentous  cyanobacteria  can  promote  increases  in  palatable  macroalgae  in   coral  reefs  by  coating  and  protecting  algae  with  secondary  metabolites  that  deter  grazing   (Fong  et  al.  2006,  Smith  et  al.  2010b).    Filamentous  cyanobacteria  can  inhibit  the   recruitment  of  coral  larvae  (Kuffner  et  al.  2006)  and  have  been  observed  interacting  at   the  borders  of  adult  coral  (Authors,  unpub.  data).    Monitoring  the  trends  of  filamentous   cyanobacteria  in  USVI  reef  systems  will  be  increasingly  important  in  future  years  in  an   effort  to  understand  the  factors  influencing  bloom  formation  and  which  reefs  are  most   vulnerable.   TCRMP  MONITORING  SUMMARY     45     Figure  9.    Filamentous  cyanobacteria  cover  (±SE)  across  TCRMP  monitoring  sites  over  time.   Nearshore Cover 0% 20% 40% 60% 80% 100% Black Point Botany Bay Brewers Bay Cane Bay Coculus Rock Coral Bay Fish Bay Great Pond Jacks Bay Kings Corner Magens Bay Salt River West Sprat Hole Offshore Cover 0% 20% 40% 60% 80% 100% Buck Island STT Buck Island STX Castle Eagle Ray Flat Cay Mutton Snapper Savana Island Seahorse South Capella South Water St. James Mesophotic 2001 2002 2003 2004 2005 2005 BL 2006 2007 2008 2009 2010 2011 2012 Cover 0% 20% 40% 60% 80% 100% Cane Bay Deep College Shoal Ginsburgs Fringe Grammanik Tiger Hind Bank FSA Lang Bank EEMP Lang Bank FSA Meri Shoal Salt River Deep BENTHIC  COVER  &  CORAL  HEALTH         46     Gorgonian  and  An+patharian  Cover   The  cover  of  gorgonians  and  antipatharians  has  been  fairly  constant  at  most  monitoring   sites  throughout  the  years  of  monitoring  (Fig.  10).      In  most  cases  they  are  a  relatively   minor  component  of  cover  because  of  their  upright  growth  form  and  small  branches.     However,  there  are  sites  that  appear  to  be  more  favorable  to  the  growth  of  gorgonians,   including  Magens  Bay,  Fish  Bay,  Coral  Bay,  Buck  Island  (St.  Croix),  Savana  Island,  South   Water,  Lang  Bank  Hind  FSA,  and  Salt  River  Deep.    Note  that  Black  Corals  (antipatharians)   typically  tend  to  be  more  prominent  in  deep  monitoring  sites,  whilst  gorgonians  tend  to   be  more  dominant  in  shallower  and  wave-­‐washed  sites.   TCRMP  MONITORING  SUMMARY     47     Figure  10.    Gorgonian  and  Antipatharian  cover  (±SE)  across  TCRMP  monitoring  sites  over  time.   Nearshore Cover 0% 5% 10% 15% 20% 25% Black Point Botany Bay Brewers Bay Cane Bay Coculus Rock Coral Bay Fish Bay Great Pond Jacks Bay Kings Corner Magens Bay Salt River West Sprat Hole Offshore Cover 0% 5% 10% 15% 20% 25% Buck Island STT Buck Island STX Castle Eagle Ray Flat Cay Mutton Snapper Savana Island Seahorse South Capella South Water St. James Mesophotic 2001 2002 2003 2004 2005 2005 BL 2006 2007 2008 2009 2010 2011 2012 Cover 0% 5% 10% 15% 20% 25% Cane Bay Deep College Shoal Ginsburgs Fringe Grammanik Tiger Hind Bank FSA Lang Bank EEMP Lang Bank FSA Meri Shoal Salt River Deep BENTHIC  COVER  &  CORAL  HEALTH         48     Sponge  Cover   Sponge  cover  has  been  constant  or  variable  at  many  offshore  and  mesophotic  sites,  but   there  is  an  indication  of  slightly  increasing  sponge  cover  at  some  nearshore  sites  (Fig.   11).    This  increase  in  epibenthic  and  boring  sponges  may  indicate  increasing  supplies  of   food,  such  as  bacteria  and  small  eukaryotes,  in  nearshore  environments.    This  may  be  a   consequence  of  increasing  nearshore  nutrient  pollution.    Further  study  needs  to  be  done   to  establish  this  linkage.   TCRMP  MONITORING  SUMMARY     49     Figure  11.    Sponge  cover  (±SE)  across  TCRMP  monitoring  sites  over  time. Nearshore Cover 0% 5% 10% 15% 20% 25% Black Point Botany Bay Brewers Bay Cane Bay Coculus Rock Coral Bay Fish Bay Great Pond Jacks Bay Kings Corner Magens Bay Salt River West Sprat Hole Offshore Cover 0% 5% 10% 15% 20% 25% Buck Island STT Buck Island STX Castle Eagle Ray Flat Cay Mutton Snapper Savana Island Seahorse South Capella South Water St. James Mesophotic 2001 2002 2003 2004 2005 2005 BL 2006 2007 2008 2009 2010 2011 2012 Cover 0% 5% 10% 15% 20% 25% Cane Bay Deep College Shoal Ginsburgs Fringe Grammanik Tiger Hind Bank FSA Lang Bank EEMP Lang Bank FSA Meri Shoal Salt River Deep FISH  COMMUNITIES         50     FISH  COMMUNITIES   In  2012  a  total  of  25,253  fish  representing  121  species  and  37  families  were   recorded  during  belt  transects  across  all  sites  off  St.  Croix  and  34,932  fish   representing  132  species  and  37  families  across  all  sites  off  St  Thomas.  Using   roving  diver  surveys  (RDS)  119  species  representing  33  families  were   observed  in  2012  off  St  Croix  and  117  species  representing  32  families  off  St.   Thomas  (see  Appendices  III-­‐VII).    Species  richness  across  most  but  not  all   sites  was  greatest  in  RDS,  designed  to  capture  rare  and  cryptic  species  (Table   3).   Overall  fish  size  distribution  on  both  St.  Croix  and  St.  Thomas  followed  trends   seen  in  earlier  years.  Fish  smaller  than  10cm  total  length  (TL)  predominated   at  all  sites.  Fifty  percent  of  the  individuals  counted  off  St.  Croix  were  less  than   5cm  TL  and  61%  were  less  than  10cm  TL.  Off  St.  Thomas,  45%  were  smaller   than  5cm  and  80%  were  under  10cm  TL.  Large  fish  (>  40cm  TL)  constituted   0.2%  (677  fish)  of  the  numeric  total  of  both  islands  combined.  This  was   similar  to  data  collected  in  2011.  St.  Thomas  sites  produced  more  of  this  size   class,  with  527  or  1.5%  of  fish  estimated  over  40cm.  Numerically  the  most   dominant  fish  across  St.  Thomas  reefs  were  striped  parrotfish  (Scarus  iserti),   bluehead  wrasse  (Thalassoma  bifaciatum),  blue  chromis  (Chromis  cyanae),   creole  wrasse  (Clepticus  parrae)  ,  bicolor  damselfish  (Stegastes  partitus),  and   threespot  damselfish  (Stegastes  planifrons).  These  six  species  made  up  over   58%  of  the  numeric  total  of  fish  observed  on  all  St.  Thomas  sites  together.  On   St  Croix  reefs,  blue  chromis,  creole  wrasse,  bluehead  wrasse,  yellowhead   wrasse  (Halichoeres  garnoti),  bicolor  damselfish  and  brown  chromis   (Chromis  multilineata)  contributed  over  62%  to  the  numeric  total  of  all  sites   together.  Most  of  these  species  were  ubiquitous  and  found  at  all  sites.  The   exception  was  creole  wrasse,  which  was  abundant  on  offshore,  mesophotic   sites,  and  nearshore  sites  adjacent  to  walls,  but  was  uncommon  on  other   shallow  water  sites.       TCRMP  SITE  SUMMARIES     51     Table  3.    Species  richness  across  sites  in  belt  transects  and  roving  diver  surveys  (RDS).   Sites  are  divided  into  nearshore,  offshore  and  mesophotic  sites  as  described  in  the  text   above.   Belt Transects (25x4) RDS   Total Number of Species Mean species per transect (±SE) Total Number of Species Nearshore Cane Bay 49 21.5±1.3 63 Great Pond 47 16.8±1.2 42 Jacks Bay 45 16.5±1.3 54 Kings Corner 63 27.9±1.0 67 Salt River West 41 19.7±1.2 55 Sprat Hole 61 23.7±0.8 64 Coculus Rock 45 20.9±1.2 48 Black Point 48 21.6±1.3 44 Brewers Bay 58 23.4±1.4 57 Botany Bay 53 22.6±1.3 59 Buck Island, St. Thomas 66 29.8±3.5 62 Coral Bay 39 16.3±0.4 54 Fish Bay 41 17.2±0.7 25 Magens Bay 48 22.2±1.7 49 Offshore Eagle Ray 56 23.2±1.2 62 Buck Island, St. Croix 56 18.9±0.9 60 Castle 60 23.6±1.1 64 Mutton Snapper 57 21.8±0.5 51 Seahorse Cottage 62 26.3±1.4 70 South Capella 61 21.8±1.2 69 South Water Island 54 21.1±1.3 57 Flat Cay 60 27.4±2.2 61 Meri Shoal 51 24.6±1.1 46 Savana Cay 61 24.4±2.3 69 Little St. James 58 21.2±1.7 59 Mesophotic Cane Bay Deep 53 19.6±0.9 47 Lang EEMP 56 21.5±1.7 62 Lang Bank 51 20.8±1.4 53 Salt River Deep 52 15.8±2.3 51 College Shoal East 64 23.4±1.0 55 Grammanik Tiger 63 23.2±1.4 47 Hind Bank 66 26.9±1.1 51 FISH  COMMUNITIES         52     Fish  Abundance   Total  fish  abundances  across  nearshore,  offshore  and  mesophotic  sites  and   years  are  shown  in  Fig.12.  Abundance  was  variable  across  sites  and  years  and   shows  no  obvious  pattern  across  time  or  space.  Slight  decreases  in   abundance  since  2005  on  St.  Croix  sites  are  thought  to  be  an  artifact  of  a   slightly  altered  methodology  and  different  survey  teams.  Sites  are  highly   dominated  by  small  pomacentrids  (damselfish)  and  labrids  (wrasses),  which   tend  to  mask  numeric  trends  in  other  fish  taxa.  Abundance  peaks  (such  as   Eagle  Ray,  2005  and  College  Shoal,  2008)  are  generally  a  result  of  large   schools  of  creole  wrasse  on  the  site.  No  change  has  been  detected  in  fish   communities  since  the  coral  bleaching  of  2005  and  subsequent  high  coral   mortality  event.  Fish  abundance  in  2012  was  similar  across  all  sites  to  data   collected  in  previous  years.     TCRMP  SITE  SUMMARIES     53                                                           Figure  12.    Fish  abundance  (±SE)  across  TCRMP  monitoring  sites  over  time.  Dotted  line  separates  St.   Croix  sites  (left)  from  St.  Thomas  (right).     0 100 200 300 400 500 600 700 800 Cane Bay Deep EEMP Lang Bank Salt River Deep College Shoal East Grammanik Bank Hind Bank East Fish/100m^2 Mesophotic   2003 2004 2005 2006 2007 2008 0 100 200 300 400 500 600 700 800 Buck Island Castle Eagle Ray Mutton Snapper Seahorse Cottage Shoal South Capella South Water Island Flat Cay Meri Shoal Savannah St. James Buck Island STT Fish/100m^2 Offshore 2003 2004 2005 2006 2007 2008 0 100 200 300 400 500 600 700 800 Cane Bay Shallow Great Pond Jacks Bay Kings Corner Salt River Shallow Sprat Hole Benner Bay Blackpoint Brewers Bay Botany Bay Coral Bay Fish Bay Megans Bay Fish/100m^2 Near Shore 2003 2004 2005 2006 2007 2008 2009 FISH  COMMUNITIES         54     Fish  Biomass   Fish  biomass  across  sites  is  shown  in  Fig.13.  The  mesophotic  sites  off  St.  Thomas   (Grammanik  Bank,  Hind  Bank  and  College  Shoal  East)  have  higher  and  some  years   dramatically  higher  average  biomass  of  fish  throughout  the  sampling  period  than   the  more  shallow  sites  across  the  territory  and  across  the  St.  Croix  mesophotic  sites.   Abundance  is  similar  or  lower  on  these  deep  St.  Thomas  reefs,  indicating  a  larger   average  fish  size.  Juveniles  of  several  species  that  occur  in  shallow  water  are  nearly   absent  on  the  mesophotic  reefs,  and  pomacentrids  and  wrasses  (except  creole   wrasse)  are  much  less  common.  The  three  mesophotic  sites  off  St.  Thomas  are  all   within  marine  protected  areas  and  are  well  offshore,  away  from  direct  land  based   pollution.  In  addition  the  Grammanik  Tiger  and  Hind  Bank  sites  are  near  or  on   multispecies  spawning  aggregation  sites  for  groupers  and  snapper.  Sampling   periods  often  overlap  slightly  aggregation  periods  for  cubera  snapper  (Lutjanus   cyanopterus)  and  this  influences  biomass  estimates.  In  contrast,  two  of  the   mesophotic  sites  off  St.  Croix  (Salt  River  Deep  and  Cane  Bay  Deep)  are  very  close  to   shore  and  are  fished  regularly.  As  with  abundance,  biomass  is  highly  variable   between  years.  No  temporal  pattern  is  evident,  and  differences  in  time  appear  to  be   seasonal  or  natural  variation.  The  fish  biomass  surveyed  in  2012  was  similar  to  data   collected  in  previous  years.             TCRMP  SITE  SUMMARIES     55     Figure  13.    Mean  fish  biomass  (±SE)  across  TCRMP  monitoring  sites  over  time.  Dotted  line  separates  St.   Croix  sites  (left)  from  St.  Thomas  (right). 0 10000 20000 30000 40000 50000 60000 70000 80000 90000 100000 Cane Bay Deep EEMP Lang Bank Salt River Deep College Shoal East Grammanik Bank Hind Bank East kg/100m^2 Mesophotic 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 0 10000 20000 30000 40000 50000 60000 70000 80000 90000 100000 Buck Island Castle Eagle Ray Mutton Snapper Seahorse Cottage Shoal South Capella South Water Island Flat Cay Buck Island Meri Shoal Savannah St. James g/100m^2 Offshore 2003 2004 2005 2006 2007 2008 2009 0 10000 20000 30000 40000 50000 60000 70000 80000 90000 100000 Cane Bay Shallow Great Pond Jacks Bay Kings Corner Salt River Shallow Sprat Hole Benner Bay Blackpoint Brewers Bay Botany Bay Coral Bay Fish Bay Megans Bay g/100m^2 Near Shore 2003 2004 2005 2006 2007 2008 2009 FISH  COMMUNITIES         56     BLACK  SPINY  SEA  URCHIN  DIADEMA  ANTILLARUM   The  abundance  of  the  black  spiny  sea  urchin  Diadema  antillarum  shows  tremendous  site-­‐ to-­‐site  variability  (Fig.  14).    In  general  the  shallowest  sites,  e.g.,  Great  Pond,  support  the   greatest  abundance  of  D.  antillarum.    Sites  with  high  abundance  of  D.  antillarum  also  tend   to  have  very  low  macroalgal  cover.    Trends  are  not  presented  as  year-­‐to-­‐year  variability  is   generally  low.    Note  that  urchins  have  not  yet  been  assessed  at  the  deep  site  Ginsburgs   Fringe.    At  Coral  Bay  there  is  a  high  abundance  of  Echinometra  spp.,  which  seems  to  be   the  dominant  grazer  that  effectively  removes  macroalgal  cover.    Future  monitoring   should  take  measurements  of  the  abundance  of  this  species.       SEA  URCHINS     57     Figure  14.    Abundance  of  the  black  spiny  sea  urchin  (Diadema  antillarum)  at  TCRMP  monitoring   sites.    Note  the  log  scale.     log (Diadema antillarum/100m2) 0.001 0.01 0.1 1 10 100 Cane Bay Deep College Shoal Grammanik Kings Corner Lang Bank EEMP Lang Bank FSA Meri Shoal Mutton Snapper Perseverence Salt River Deep Savana Seahorse South Capella South Water Sprat Hole Hind Bank St. James Fish Bay Flat Cay Jacks Bay Buck Island STX Salt River West Buck Island STT Eagle Ray Black Point Coral Bay Cane Bay Magens Bay Brewers Bay Botany Bay Castle Coculus Rock Great Pond