Brief description
An understanding of coral population dynamics (demography) is needed when designing and evaluating studies that aim to detect the effects of natural and anthropogenic mediated impacts on coral communities, and in particular when making predictions about the likelihood of and speed of recovery from such impacts. This study was undertaken to gather baseline data on demographic processes to improve our understanding of the fundamental population dynamics in relation to recruitment, growth and survival of reef building corals in the Pilbara. Measurements of key demographic processes were carried out annually over two years (April 2014 and March 2015) at Enderby and West Lewis Islands in the Dampier Archipelago, Western Australia. Locations sampled at Dampier Archipelago (where coral populations existed) were relatively unimpacted by bleaching mortality that occurred between 2011-2014. At each location permanent transects were established sufficient to provide up to several hundred tagged colonies in order to derive valid demographic rates (growth, mortality, shrinkage, fragmentation) for individuals of each size class, as well as to allow estimates of recruitment. Censuses were conducted using a combination of wide angle photographs of the permanent transects, detailed field censuses of recruits and adult corals, and direct measurements of tagged colonies. The corals investigated in this study were Acropora millepora, Turbinaria mesenterina and massive Porites spp. (mainly P. lobata and P. lutea). These species were chosen because they were among the most common coral taxa on reefs of the Pilbara, and on many reefs globally, making them fundamental to reef primary productivity and carbonate accretion, and because they have contrasting life histories and susceptibilities to disturbances.Lineage
Progress Code: completed
Maintenance and Update Frequency: asNeeded
Statement: Four permanent transects (30 m in length) were established at West Lewis Island, and two at Enderby Island between 20-30 May 2014. The start and finish points of transects were marked with a star picket and at 5 m intervals with steel reinforcing rod. The position of all star pickets were recorded using a hand-held GPS.
Along each permanent transect, benthic photographs were taken to quantify the percentage cover of coral assemblages as well as other benthic substrata. Photographs were taken at a distance of approximately 50 cm from the substratum and spaced every 50 cm on each side of the permanent transects. Percentage cover was quantified by classifying the benthos beneath 6 fixed points on each image (300 points per transect) using the software package Transect Measure (V 2.41 http://www.seagis.com.au/transect.htm).
For each species, population size-frequency distributions were obtained by recording the size of all colonies within a one metre distance on either side of permanent transects (60 m2). Using the permanent transect as a reference point, the locations of all tagged colonies were recorded, tagged, measured and photographed. Tagged colonies were re-located and re-measured approximately one year later. A total of 737 corals were examined; 473 corals from Enderby Island and 264 from West Lewis Islands. Similar numbers of massive Porites (279), T. mesenterina (229) and A. millepora (272) colonies were tagged. Of the colonies tagged 733 corals were re-located a year later and assessed for survival, growth, partial mortality and fission. Refer to the full report for further details.
Along each permanent transect, benthic photographs were taken to quantify the percentage cover of coral assemblages as well as other benthic substrata. Photographs were taken at a distance of approximately 50 cm from the substratum and spaced every 50 cm on each side of the permanent transects. Percentage cover was quantified by classifying the benthos beneath 6 fixed points on each image (300 points per transect) using the software package Transect Measure (V 2.41 http://www.seagis.com.au/transect.htm).
For each species, population size-frequency distributions were obtained by recording the size of all colonies within a one metre distance on either side of permanent transects (60 m2). Using the permanent transect as a reference point, the locations of all tagged colonies were recorded, tagged, measured and photographed. Tagged colonies were re-located and re-measured approximately one year later. A total of 737 corals were examined; 473 corals from Enderby Island and 264 from West Lewis Islands. Similar numbers of massive Porites (279), T. mesenterina (229) and A. millepora (272) colonies were tagged. Of the colonies tagged 733 corals were re-located a year later and assessed for survival, growth, partial mortality and fission. Refer to the full report for further details.
Notes
CreditThis work was a component of the WAMSI program http://www.wamsi.org.au/ - WAMSI Dredging Node
Credit
Russ Babcock CSIRO Damian Thomson CSIRO James Gilmour AIMS Western Australian Marine Science Institution (WAMSI)
Russ Babcock CSIRO Damian Thomson CSIRO James Gilmour AIMS Western Australian Marine Science Institution (WAMSI)
Data time period: 2014-05-20 to 2015-06-30
text: westlimit=116.55; southlimit=-20.59; eastlimit=116.64; northlimit=-20.55
text: uplimit=0; downlimit=-5
Subjects
ANIMALS/INVERTEBRATES |
Anthozoans/Hexacorals |
AQUATIC ECOSYSTEMS |
Acropora millepora |
Benthic Habitat |
BIOLOGICAL CLASSIFICATION |
BIOSPHERE |
CNIDARIANS |
Coastal Habitat |
EARTH SCIENCE |
Global / Oceans | Indian Ocean |
Marine Features (Australia) | Australian North West Shelf, WA |
Pilbara MCP |
Porites spp. |
Turbinaria mesenterina |
WA Data Inventory 2007-8 |
Western Australian Marine Science Institute |
biota |
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Other Information
Identifiers
- global : 0f441ced-8462-373c-e053-08114f8c62d0
- Local : Marlin Record Number: 14465
- Local : Anzlic Identifier: ANZCW0306014465
