@article{fdi:010048209,
  title = {{C}hanges of coral communities over 35 years : integrating in situ and remote-sensing data on {S}aint-{L}eu {R}eef (la {R}eunion, {I}ndian {O}cean)},
  author = {{S}copelitis, {J}. and {A}ndr{\'e}fou{\¨e}t, {S}erge and {P}hinn, {S}. and {C}habanet, {P}ascale and {N}aim, {O}. and {T}ourrand, {C}. and {D}one, {T}.},
  editor = {},
  language = {{ENG}},
  abstract = {{M}onitoring coral reef communities at a decadal scale is necessary to understand and project their dynamics to provide a basis for reef management in light of disturbances and climate change. {C}omplementing infrequent and localised in situ observations, time-series of aerial photographs and remotely sensed satellite images provide a means of monitoring the position and extent of reef-top coral communities, vegetation and abiotic substrata at the whole reef scale. {T}he aim of the present study was to map such changes on {S}aint-{L}eu {R}eef ({L}a {R}eunion) between 1973 and 2007. {T}he period included two cyclones (1989, 2002) and one severe bleaching event (2002). {V}ertical images of the reef were recorded in five aerial photographs (1973,1978,1989,1997, and 2003) and two {Q}uickbird satellite images (2002, 2006) during that time. {Q}uantitative in situ observations of parts of the reef-top were also available both to document ecological and substratum characteristics that produce the color and texture observable in the photos and satellite images. {C}oral communities were mapped on all images using manual delineation of polygons identified according to color and texture contrast. {T}he 2006 {Q}uickbird image was used as the mapping base and 15 types of coral communities were identified from a reef survey conducted in 2007. {T}his hierarchical typology used coral growth forms, live and dead coral cover, macro-algae, substratum (sand, rubble and platform) and, to a lesser extent, coral taxonomy. {T}he polygons at date t were over-laid onto image t - 1 across the whole series and their boundaries were manually edited to match the pattern on the earlier image. {L}abelling of polygons was guided by field-survey data and maps. {F}or coral-dominated patches, six successive pairs of maps from 1973 to 2006 were compared to produce 'coral community change maps' for that period. {D}espite the multiple disturbance events, the coral community distribution and composition in 2006 on {S}aint-{L}eu {R}eef did not display major differences compared to 1973. {T}his suggests a high degree of coral resilience at the site, led by rapid recovery of compact branching corals. {T}he mapping techniques overcame challenges due to different image quality and the sparsity of in situ observations in time and space. {O}ur results demonstrate the potential for further application of reef monitoring protocols based on complementary in situ and remote-sensing data to help understand the dynamics of reef-top coral reef communities and geomorphology over years to decades.},
  keywords = {coral reefs ; ecosystem resilience ; cyclones ; bleaching ; aerial ; photographs ; change detection ; {REUNION}},
  booktitle = {},
  journal = {{E}stuarine {C}oastal and {S}helf {S}cience},
  volume = {84},
  numero = {3},
  pages = {342--352},
  ISSN = {0272-7714},
  year = {2009},
  DOI = {10.1016/j.ecss.2009.04.030},
  URL = {https://www.documentation.ird.fr/hor/fdi:010048209},
}