Brief description
Aquatic flora surveys were conducted in Oyster Harbour between 1998 and 2019. Surveys were initially conducted in 1988, 1996 and 2016 by the WA Government Department of Water (described by 2013 "Synthesis of seagrass mapping studies"), and again in 2019 by the Department of Water and Environmental Regulation "Oyster Harbour Seagrass Survey - Cover (DWER-109)".Data access is provided to the initial WA DoW surveys. See associated DWER record in Data WA catalogue for access to newer surveys.
Lineage
Maintenance and Update Frequency: notPlanned
Statement: Survey years 1988, 1996 & 2006:
High quality aerial photographs were obtained and interpreted to identify seagrass areas. Intersecting transects across these areas were used to ground truth density (percentage cover) and species composition of the seagrass habitats. The ground-truthing field work was undertaken by underwater video tows, shore transects, and spot dives and observations from a small punt or boat equipped with GPS tracking equipment. These areas were then digitised in ARC GIS.
Limited resources and the methodology necessitated distributions and densities to be averaged over large areas. Seagrass distributions and changes in density may have been under or over represented in different parts of the harbour, making comparisons to previous surveys and estimations of change difficult.
Survey year 2019:
Oyster Harbour was surveyed in March 2019. Seagrass species distribution (Posidonia australis and Posidonia sinuousa) and cover (as percentage cover classes: 0, 75%) was recorded across 216 observations points across the estuary. The type of meadow (continuous or patchy), epiphytic cover on seagrass (as none, very low, low, medium, high or very high), and macroalgae cover (as percentage cover in categories: 0, 75%) were recorded at each site. At approximately a third of the sites, physical water profiles, secchi depth and euphotic depth were recorded.
High quality aerial photographs were obtained and interpreted to identify seagrass areas. Intersecting transects across these areas were used to ground truth density (percentage cover) and species composition of the seagrass habitats. The ground-truthing field work was undertaken by underwater video tows, shore transects, and spot dives and observations from a small punt or boat equipped with GPS tracking equipment. These areas were then digitised in ARC GIS.
Limited resources and the methodology necessitated distributions and densities to be averaged over large areas. Seagrass distributions and changes in density may have been under or over represented in different parts of the harbour, making comparisons to previous surveys and estimations of change difficult.
Survey year 2019:
Oyster Harbour was surveyed in March 2019. Seagrass species distribution (Posidonia australis and Posidonia sinuousa) and cover (as percentage cover classes: 0, 75%) was recorded across 216 observations points across the estuary. The type of meadow (continuous or patchy), epiphytic cover on seagrass (as none, very low, low, medium, high or very high), and macroalgae cover (as percentage cover in categories: 0, 75%) were recorded at each site. At approximately a third of the sites, physical water profiles, secchi depth and euphotic depth were recorded.
Notes
CreditDepartment of Water and Environmental Regulation, Government of Western Australia.
text: westlimit=117.94080999999998; southlimit=-34.997757472528; eastlimit=117.98173000000001; northlimit=-34.946200000000005
Subjects
Abundance of biota |
Biological Sciences |
Benthic habitat |
EARTH SCIENCE | BIOLOGICAL CLASSIFICATION | PLANTS | ANGIOSPERMS (FLOWERING PLANTS) | MONOCOTS | SEAGRASS |
EARTH SCIENCE | BIOSPHERE | AQUATIC ECOSYSTEMS | BENTHIC HABITAT |
EARTH SCIENCE | BIOSPHERE | AQUATIC ECOSYSTEMS | MARINE HABITAT |
Ecology |
Environmental Science and Management |
Environmental Sciences |
Environmental Management |
Environmental Sciences Not Elsewhere Classified |
Marine and Estuarine Ecology (Incl. Marine Ichthyology) |
Other Environmental Sciences |
WESTERN AUSTRALIA |
biota |
cameras |
research aeroplane |
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Other Information
(Related metadata record [Data WA catalogue])
uri :
https://catalogue.data.wa.gov.au/dataset/oyster-harbour-seagrass-survey-cover
global : a1a2d181-d453-43e1-ae2e-627ec2a9bd1e
Identifiers
- global : 1D34BD8E-74B1-41EB-8F81-398539215527
