IMAS Metadata Catalogue
Dugong and Turtle seagrass habitats in the North-West Torres Strait
This dataset describes seagrass at 34 individual meadows from surveys of Dugong and Turtle habitats in the North-West Torres Strait for November 2015 and January 2016. The data includes information on seagrass species, biomass, diversity, and BMI and algae percent cover.
This meadow (polygon) layer provides summary information for all survey sites within the 34 individual seagrass meadows mapped in 2015-2016 with information including individual meadow ID, meadow location (intertidal/shallow subtidal/subtidal), meadow density based on mean biomass, meadow area, dominant seagrass species, seagrass species present, survey dates, survey method, and data custodian. ESRI and Landsat satellite image basemaps were used as background source data to check meadow and site boundaries, and re-map where required.
The data described by this record is current as of 01/12/2016 for use in the Seamap Australia project. Newer versions of the data, additional 'point' data for 853 sites, and alternative download formats are available from eAtlas. http://eatlas.org.au/geonetwork/srv/eng/metadata.show?uuid=034ce816-0777-4bbd-aefc-8b73bd540245
Simple
Identification info
- Date (Publication)
- 2016-06-09
Principal investigator
Centre for Tropical Waters and Aquatic Research (TropWATER), James Cook University (JCU) - Carter, Alex, Dr (Senior Research Officer)
James Cook University (JCU)
Cairns
Queensland
4878
Australia
Collaborator
Centre for Tropical Waters and Aquatic Research (TropWATER), James Cook University (JCU) - Rasheed, Michael, Dr (Principal Research Scientist)
James Cook University (JCU)
Cairns
Queensland
4878
Australia
- Status
- Completed
Point of contact
Centre for Tropical Waters and Aquatic Research (TropWATER), James Cook University (JCU) - Carter, Alex, Dr
James Cook University (JCU)
Cairns
Queensland
4878
Australia
- Spatial representation type
- Vector
- Topic category
-
- Biota
Extent
N
S
E
W
))
Temporal extent
- Time position
- 2015-11-01T00:00:00
- Time position
- 2016-01-31T00:00:00
Resource format
- Title
- ESRI Shapefile
- Date
- Edition
- -
- Keywords (Theme)
-
- marine
- Global Change Master Directory (GCMD) Earth Science Keywords Version 8.0
- Keywords (Theme)
-
- Benthic habitat
- Meadow_ID
- Inter_sub
- Method
- No_sites
- Survey
- D_range
- Biomass
- AREA
- R_m
- R_Ha
- Seamap_Den
Resource specific usage
- Specific usage
- Data supplied for use by the Seamap Australia Project.
- ()
Resource constraints
- Classification
- Unclassified
Resource constraints
- Linkage
-
http://i.creativecommons.org/l/by/4.0/88x31.png
License Graphic
- Title
- Creative Commons Attribution 4.0 International License
- Website
-
http://creativecommons.org/licenses/by/4.0/
License Text
- Other constraints
- Cite data as: Carter A, Rasheed M (2016). Dugong and Turtle seagrass habitats in the North-West Torres Strait. James Cook University. Data accessed at http://metadata.imas.utas.edu.au/geonetwork/srv/en/metadata.show?uuid=034ce816-0777-4bbd-aefc-8b73bd540245 on (access date).
- Other constraints
- This dataset is hosted by the Institute for Marine and Antarctic Studies (IMAS), University of Tasmania, on behalf of James Cook University (JCU) for the purposes of the Seamap Australia collaborative project (testing a national marine benthic habitat classification scheme).
- Language
- English
- Character encoding
- UTF8
- Supplemental Information
- Carter, A. B. and Rasheed, M. A. (2016) Assessment of Key Dugong and Turtle Seagrass Resources in North-west Torres Strait. Report to the National Environmental Science Programme and Torres Strait Regional Authority. Reef and Rainforest Research Centre Limited, Cairns (40 pp).
Content Information
- Content type
- Physical measurement
- Description
- ID of the seagrass meadow surveyed.
- Name
-
Meadow_ID
- Description
- Meadows were classed according to three categories, although some meadows cover a range of these locations: Intertidal, Subtidal, or Shallow subtidal. See project report for full details.
- Name
-
Inter_sub
- Description
- Sampling and mapping methods – helicopter aerial surveying or boat.
- Name
-
Method
- Description
- Number of survey sites that fall within the seagrass meadow.
- Name
-
No_sites
- Description
- Date of seagrass meadow survey.
- Name
-
Survey
- Description
- Depth range of surveyed seagrass meadow.
- Name
-
D_range
- Identifier
- http://vocab.nerc.ac.uk/collection/P06/current/ULAA
- Name
- Metres
- Description
- Mean above-ground meadow biomass in g DW m-2 (+ standard error if available) determined from visual surveys. See project report for full details.
- Name
-
Biomass
- Name
- Grams dry weight per square metre
- Description
- Area of seagrass meadow.
- Name
-
AREA
- Name
- Hectares
- Description
- Reliability estimate of mapping precision (m).
- Name
-
R_m
- Identifier
- http://vocab.nerc.ac.uk/collection/P06/current/ULAA
- Name
- Metres
- Description
- Reliability estimate of mapping precision (ha).
- Name
-
R_Ha
- Name
- Hectares
- Description
- All seagrass species present.
- Name
-
Species_2
Identifier
- Description
- Seagrass community type (species composition). See project report for full nomenclature details.
- Name
-
Meadow_typ
Identifier
- Description
- Meadow density categories (light, moderate, dense) were determined by the consistency of mean above-ground biomass of the dominant species. See project report for full details.
- Name
-
Seamap_Den
- Description
- Appended to original data for styling purposes for the Seamap Australia Project.
- Name
-
Benthic habitat
- Name
-
SM_HAB_CLS
Distribution Information
- Distribution format
-
-
ESRI Shapefile
-
ESRI Shapefile
- OnLine resource
-
SHAPE-ZIP
DATA ACCESS - This OGC WFS service returns the data (NW Torres Strait seagrass) in Shapefile format.
- OnLine resource
-
seamap:SeamapAus_QLD_NWTorresStrait_seagrass_2016
MAP - NW Torres Strait seagrass meadows
- OnLine resource
-
REPORT - Final project report [direct download]
- OnLine resource
-
WEBSITE - Project website
- OnLine resource
-
Original metadata record [eAtlas catalogue]
Data quality info
- Hierarchy level
- Dataset
Report
- Measure description
- Mapping precision estimates (in metres) were based on the mapping method used for that meadow (Table 3 "Mapping precision and methods for seagrass meadows" in final report). Mapping precision estimates ranged from 1-10m for intertidal seagrass meadows to >100m for patchy subtidal meadows. Subtidal meadow mapping precision estimates were based on the distance between sites with and without seagrass. The mapping precision estimate was used to calculate an error buffer around each meadow; the area of this buffer is expressed as a meadow reliability estimate (R) in hectares.
Resource lineage
- Statement
- The sampling methods used to study, describe and monitor seagrass meadows were developed by the TropWATER Seagrass Group and tailored to the location and habitat surveyed; these are described in detail in the relevant publications (https://research.jcu.edu.au/tropwater). 1. Location - Latitude and longitude was recorded by GPS at each site. Depth was recorded when sampling by boat and converted to depth below mean sea level (dbMSL) in metres. 2 Seagrass metrics - Above-ground biomass was determined using a “visual estimates of biomass” technique (Mellors, 1991) using trained observers. A linear regression was calculated for the relationship between the observer ranks and the harvested values. This regression was used to calculate above-ground biomass for all estimated ranks made from the survey sites. Biomass ranks were then converted into above-ground biomass estimates in grams dry weight per square metre (gdw m-2). Observers ranked seagrass biomass, and the percent contribution of each species to that biomass, using video transects, grabs, free divers, and helicopter: * Video transect: Commonly used for subtidal meadows sampled from larger boats. At each transect site an underwater CCTV camera system was lowered from the vessel to the bottom. For each transect the camera was towed at drift speed (less than one knot) for approximately 100m. Footage was observed on a TV monitor and digitally recorded. The video was paused at ten random time frames and an observer ranked seagrass biomass and species composition. On completion of the video analysis, the video observer ranked five additional quadrats that had been previously videoed for calibration. These quadrats were videoed in front of a stationary camera, then harvested, dried and weighed. * Helicopter: Commonly used for intertidal surveys. At each site seagrass above-ground biomass and species composition were estimated from three 0.25 m2 quadrats placed randomly within a 10m2 circular area. Seagrass percent cover and sediment type were recorded at each site. The “visual estimates of biomass” technique when applied to helicopter surveys (and free diving/camera drops – see below) involves ranking while referring to a series of quadrat photographs of similar seagrass habitats for which the above-ground biomass has previously been measured. Three separate biomass scales were used: low-biomass, high-biomass, and Enhalus-biomass. The relative proportion (percentage) of the above-ground biomass of each seagrass species within each survey quadrat was also recorded. Field biomass ranks were converted into above-ground biomass estimates in grams dry weight per square metre (gdw m-2). At the completion of sampling each observer ranked a series of calibration quadrats as per video transect surveys. * Camera drop/free diving: Commonly used for shallow subtidal meadows sampled from a small boat. Sampling follows the same protocol as helicopter surveys but the three quadrats were either assessed by a free diver with quadrat, or by an underwater CCTV camera system camera attached to a frame. Video footage was observed on a TV monitor and seagrass ranked in real time, with the camera frame serving as a quadrat. * van Veen grab: Commonly used for shallow subtidal meadows sampled from a small boat in conjunction with camera drops, or to record seagrass presence/absence where visibility was too poor for camera drops. A sample of seagrass was collected using a van Veen grab (grab area 0.0625 m2) to identify species present at each site. Species identified from the grab sample were used to inform species composition assessments made from the video drops (Kuo et al., 1989). 3 Benthic macro-invertebrates - A visual estimate of benthic macro-invertebrate (BMI) percent cover was recorded at each shallow subtidal and intertidal site according to four broad taxonomic groups: * Hard corals – All scleractinian corals including massive, branching, tabular, digitate and mushroom. * Soft corals – All alcyonarian corals, i.e. corals lacking a hard limestone skeleton. * Sponges * Other BMI – Any other BMI identified, e.g. hydroids, ascidians, barnacles, oysters, molluscs. Other BMI are listed in the “comments” column of the GIS site layer. 4 Algae - A visual estimate of algae percent cover was recorded at each shallow subtidal and intertidal site. When present, algae were categorised into five functional groups and the percent contribution of each functional group was estimated: * Erect macrophytes – Macrophytic algae with an erect growth form and high level of cellular differentiation, e.g. Sargassum, Caulerpa and Galaxaura species. * Erect calcareous – Algae with erect growth form and high level of cellular differentiation containing calcified segments, e.g. Halimeda species. * Filamentous – Thin, thread-like algae with little cellular differentiation. * Encrusting – Algae that grows in sheet-like form attached to the substrate or benthos, e.g. coralline algae. * Turf mat – Algae that forms a dense mat on the substrate.
- Hierarchy level
- Dataset
Resource lineage
- Statement
- Data Dictionary: * Meadow location was classed according to whether meadows were intertidal (all sites surveyed by helicopter), shallow subtidal (generally an extension of an intertidal meadow into shallow waters <5m deep), or subtidal (no intertidal sites adjoining the meadow). * Seagrass community types were determined according to species composition within a meadow. Species composition was based on the percent each species’ biomass contributed to mean meadow biomass. A standard nomenclature system was used to categorize each meadow (see Table 1 "Nomenclature for seagrass community types" in final report). This nomenclature also included a measure of meadow density categories (light, moderate, dense) determined by mean biomass of the dominant species within the meadow (see Table 2 "Density categories and mean above-ground biomass ranges for each species used in determining seagrass community density" in final report). Further information can be found in this publication: Carter, A. B. and Rasheed, M. A. (2016) Assessment of Key Dugong and Turtle Seagrass Resources in North-west Torres Strait. Report to the National Environmental Science Programme and Torres Strait Regional Authority. Reef and Rainforest Research Centre Limited, Cairns (40 pp).
- Hierarchy level
- Attribute
Metadata
- Metadata identifier
-
034ce816-0777-4bbd-aefc-8b73bd540245
- Language
- English
- Character encoding
- UTF8
Point of contact
- Parent metadata
Type of resource
- Resource scope
- Dataset
- Metadata linkage
-
https://metadata.imas.utas.edu.au/geonetwork/srv/eng/catalog.search#/metadata/034ce816-0777-4bbd-aefc-8b73bd540245
Point of truth URL of this metadata record
- Date info (Creation)
- 2020-09-23T12:24:07
- Date info (Revision)
- 2020-09-23T12:24:07
Metadata standard
- Title
- ISO 19115-3:2018
Overviews
Spatial extent
N
S
E
W
Provided by
Associated resources
Not available