IMAS Metadata Catalogue
Video surveys of long spined sea urchin (Centrostephanus rodgersii) barrens habitat, Maria Island, eastern Tasmania
The spatial extent of C. rodgersii "barrens" was estimated by surveying rocky reef habitat with a towed underwater video system. Sampling took place at 13 regions along the east coast of Tasmania, each comprising 3 subsites, this dataset refers to the Maria Island region, and its 3 subsites: Beaching, Bunker and Mistaken Cape.
Simple
Identification info
- Date (Creation)
- 2007-10-30T15:58:00
Principal investigator
School of Zoology, University of Tasmania (UTAS) - Johnson, Craig, Prof.
Private Bag 5
Hobart
TAS
7001
Australia
- Purpose
- To determine the distribution of barrens habitat associated with the long spined sea urchin (Centrostephanus rodgersii) on the east coast of Tasmania - Maria Island.
- Credit
- Ling, Scott
- Credit
- Ross, Jeff, Dr
- Credit
- Funding: FRDC project 2001/044
- Status
- Completed
Principal investigator
Institute for Marine and Antarctic Studies (IMAS), University of Tasmania (UTAS) - Johnson, Craig, Prof.
IMAS - Sandy Bay
Private Bag 129
Hobart
Tasmania
7001
Australia
- Spatial representation type
- Text, table
- Topic category
-
- Biota
Extent
N
S
E
W
))
Temporal extent
- Time period
- 2002-03-04T00:00:00 2002-03-07T00:00:00
Vertical element
- Minimum value
- 4
- Maximum value
- 44
- Identifier
- EPSG::5715
- Name
- MSL depth
- Maintenance and update frequency
- Not planned
Resource format
- Title
- Microsoft Excel (xls)
- Date
- Edition
- 2003
- CAAB - Codes for Australian Aquatic Biota v2.
-
- 25 211001
- Centrostephanus rodgersii
- Global Change Master Directory (GCMD) Earth Science Keywords Version 8.0
- Keywords (Discipline)
-
- Temperate Reef
- Australian and New Zealand Standard Research Classification (ANZSRC): Fields of Research
- Keywords (Theme)
-
- Substratum type
- Algal coverage
- Urchin barren coverage
Resource constraints
- Classification
- Unclassified
Resource constraints
- Use limitation
- The data described in this record are the intellectual property of the University of Tasmania through the School of Zoology and the Tasmanian Aquaculture and Fisheries Institute.
Resource constraints
- Linkage
-
http://i.creativecommons.org/l/by-sa/2.5/au/88x31.png
License Graphic
- Title
- Creative Commons Attribution-Share Alike 2.5 Australia License
- Website
-
http://creativecommons.org/licenses/by-sa/2.5/au/
License Text
- Other constraints
- The citation in a list of references is: citation author name/s (year metadata published), metadata title. Citation author organisation/s. File identifier and Data accessed at (add http link).
Associated resource
- Title
- Surveys of the long spined sea urchin Centrostephanus rodgersii
- Date (Creation)
- 2011-08-31T00:00:00
- Character encoding
- UTF8
- Environment description
- Microsoft Excel spreadsheets (xls) and word document (doc) - video tow data (includes all sites and subsites but not the temporal factor (centro_video_data_FRDC2001_044. xls) - GPS coordinates for sites/subsites (GPS_coordinates_dive_transects_FRDC_____survey_2001_044.xls) - document identifying keys used for data (AnalysisLog.doc)
- Supplemental Information
- References: Johnson, C., Ling, S., Ross, J., Shepherd, S. and Miller, K., 2005. Establishment of the long-spined sea urchin (Centrostephanus rodgersii) in Tasmania: First assessment of potential threats to fisheries. FRDC Final Report, Project No. 2001/044. University of Tasmania, Tasmanian Aquaculture and Fisheries Institute, School of Zoology. Smith, E. 2006. Establishment of the long-spined sea urchin - Centrostephanus rogersii. Fishing Today - Tasmanian Fishing Industry News, Volume 19, No. 1, Feb/March. http://www.dpiw.tas.gov.au/inter.nsf/Attachments/LBUN-6MV6CV?open
Content Information
- Content type
- Physical measurement
- Name
-
Substratum type
- Name
-
Algal coverage
- Name
-
Urchin barren coverage
Distribution Information
- Distribution format
-
-
Microsoft Excel (xls)
-
Microsoft Excel (xls)
Distributor
- OnLine resource
-
DATA - Maria Island [direct download]
- OnLine resource
-
SUPPLEMENTARY INFO - GPS coordinates for sites and subsites (.xls) [direct download]
- OnLine resource
-
RAW VIDEO - Maria Island: Bunker Bay [direct download]
- OnLine resource
-
RAW VIDEO - Maria Island: Mistaken Cape [direct download]
- OnLine resource
-
RAW VIDEO - Maria Island: Beaching Bay [direct download]
- OnLine resource
-
RAW VIDEO - Maria Island: Beaching Bay 2 [direct download]
Resource lineage
- Statement
- Note: no video file exists for one of the mistaken cape transects. Sampling took place at 13 regions along the east coast of Tasmania, each comprising 3 subsites - this dataset refers to one region - Maria Island, and the three subsites: Beaching, Bunker and Mistaken Cape. At each subsite two video transects were conducted perpendicular to the shore and two transects were conducted parallel with the shore. The perpendicular transects covered depths from 1 to 45 m, while parallel transects were within a depth range of 15 to 20 m. In most cases, perpendicular tows spanned the width of reef from the shore to the reef fringe/sand edge. Parallel tows were conducted for 20-30 minutes or approximately 1 km in length (straight-line distance from tow start point), but tow speed varied depending on weather conditions and reef topography. Thus, at each site, ca. 6-7 km of inshore rocky reef was surveyed for barren habitat using this method, with the entire survey covering > 80 km of reef. Substrate and habitat type were recorded using video analysis, with 4 categories of urchin barren habitat recognised (see below for definitions). Substratum types were resolved as either "unclassified reef" if the substratum type was unclear (usually where macroalgal cover prevented a clear view of the substratum) or, where the substratum could be discerned, "flat rock" with little apparent relief, "boulder reef", "cobble", "gravel", "pebble", or "sand". Habitat types denoted either C. rodgersii barrens, or habitat dominated by particular canopy-forming species. Habitat was classified as sea urchin barrens when the understorey was completely denuded, and the overstorey occupied <15% cover. We recognized four categories of sea urchin barrens habitat: Type 1 barrens denotes continuous barrens habitat in the camera field of view for > 10 m, while the other 3 categories are different types of "patchy" incipient barrens, where a patch was defined as a section of reef that was not continuously barren for 10 m. Type 2 barrens was defined as patchy barren where barrens covered > 40% of the bottom; Type 3 barrens defined patchy barrens in which barrens occupied between 20 - 40% cover; while Type 4 barrens referred to patchy barren where barren cover was < 20% cover.
- Hierarchy level
- Dataset
Resource lineage
- Statement
- The video camera system was a scaled down version of the system developed by Barker et al. (1999). The camera was mounted inside a positively buoyant protective cage with an attached chain to provide stability and ensure that the camera and frame floated 1-2 m above the sea floor. This system enabled towing the camera across rocky reef with rough topographic relief so that the camera remained a similar distance off the sea floor regardless of depth, providing a field of view ca. 3-4 m wide depending on surge and topography. The camera system was linked to (1) an onboard video recorder to capture the image, date, time, position and depth; (2) a real time monitor; and (3) computer which logged the depth under the boat (from an electronic depth sounder) and position (from a GPS) of the vessel at 4 s intervals, and comments input by the operator. Note that data on depth and position related to the boat, while the camera was on a tow line 40-55 m behind the boat. In the laboratory, the video footage was examined in detail to classify habitat types, which was recorded against the logged data. In this way, the total distance of each video transect tow, and the proportion of each transect that was classified as C. rodgersii barrens and other habitat types was estimated from the logged GPS coordinates. In the event of poor GPS signals (e.g. at base of large cliffs), position was back-calculated by interpolating between fixes determined from good satellite coverage. GPS used datum WGS84. Note GPS inaccuracy may have resulted if datum type unknowingly changed etc (e.g. some points may appear on land, however subsite names may also give an indication as to actual location).
- Hierarchy level
- Collection hardware
Resource lineage
- Statement
- Mistaken Cape 1: Video for both tows is extremely poor quality. In addition to poor light the digital tapes appear to be reused and seemed to have suffered. They are covered by moving diagonal interference lines and ?snow?. The CD-Rom images lack these interference patterns but are still very dark and grainy making analysis, particularly substrate identification difficult. Parallel Tow: The notes indicate that the Genlock for this tow finishes at 6:30:51 but the data file still logged data points till 6:31:51. The video continues for a further 21.5 min past this point. But when Genlock is lost the video jumps. The image appears to be from another tow completely. (Light levels, better video quality, depth, presence of sand, different algal community all tend to indicate a major site/location shift. No such shift is recorded on the Notes sheet or appears in the latitude/longitude in the remaining extra minute of data. By inference we suspect this is an earlier tow video.) The last minute has been left on the file but there is no substrate or algal data with it only a note about the video stopping. This probably should be deleted before analysis (the extra minute).
- Hierarchy level
- Collection session
Metadata
- Metadata identifier
-
767d31e0-207d-11dd-8d4a-00188b4c0af8
- 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/767d31e0-207d-11dd-8d4a-00188b4c0af8
Point of truth URL of this metadata record
- Date info (Creation)
- 2021-03-30T00:20:13
- Date info (Revision)
- 2021-03-30T00:20:13
Metadata standard
- Title
- ISO 19115-3:2018
Overviews
Spatial extent
N
S
E
W
Provided by
Associated resources
Not available