Title

Catch and Effort Cells for the Bass Strait General Offshore Fishery 

Alternate title

CE_BASS_STRAIT_1998 

Purpose

The CE_BASS_STRAIT_1998 layer provides a grid of cells on which various summary catch and effort data for the Bass Strait fisheries can be imported, displayed, and analysed. Catch and effort data can be used to display trends in fishing activity. Summary information such as extent of catch, total catch, effort, catch per unit area, and catch per unit effort can be represented. This information is crucial to ensure effective fisheries management, research and monitoring. This data set may be displayed in conjunction with a variety of environmental data capable of providing an insight into the behaviour of the many species caught in Bass Strait. A depth model, ocean currents, temperature profiles and salinity levels, are useful data that may assist in gaining an understanding into the ecology of these species. 

Credit

Anne Gason, Allister Coots 

Supplemental Information

History: 4 Feb 2004 - Addition of new attributes and attribute values. 2 Mar 2005 - Projection of shapefile to GDA. Current Design Issues: This layer was designed in accordance with specifications supplied by Anne Gason, Department of Primary Industries (DPI), Queenscliff. Future Design Issues: None. Related Documents: None CGDL DEPTH250 layer metadata (the RAN Hydrographic Office sourced layer with the Victorian coastline) is available at the address below to DSE/DPI staff only. Metadata for the GEODATA COAST100K layer can be found in Appendix A of the GEODATA COAST100K 1992 Product User Guide available at http://www.ga.gov.au/data_download/docs/coast1992_userguide.pdf. You will need Adobe Acrobat Reader to view this document. CGDL DEPTH250 layer: http://sysx/cgi-bin/websql/metadata/dataset_full.hts?name=DEPTH250 

Status

Completed  

Horizontal Accuracy

250m  

Code

4283 

Maintenance and update frequency

As needed  

Topic category

• Farming

Use limitation

DataVic 

Classification

Unclassified  

Statement

Dataset Source: Geoscience Australia National Mapping Division - GEODATA COAST100K dataset, RAN Hydrographic Office - 1:250,000 National Bathymetric Map Series Rock Lobster fishery areas Dataset Originality: Derived 

Description

Collection Method: Generated from Latitude and Longitude 

Description

After the Rock Lobster area cells were copied to a new layer, one horizontal boundary line (at latitude 39°12'S) was removed and other horizontal lines at 10 minute intervals were added to intersect the existing coverage. The land portions of these lines were removed, regions were created from the polygons, and the regions were attributed with a new item to hold a grid reference style of area code (e.g. E2), which does not use the letters I or O in the row codes to avoid possible confusion with the digits 1 or 0. The Tasmanian islands were also added to the coverage and any area portions within these islands were removed. The Victoria/South Australia border was moved from longitude 141°E to the longitude listed in the OCS Agreement, 140° 57.9'E in a later update. Later still, the area code attribute in the polygons was changed from a numeric item (left over from the Rock Lobster layer) to a character item and modified to the grid reference codes used in the regions. In a further update, the regions from the source coverage were converted to a polygon shapefile that was projected into the Geocentric Datum of Australia (GDA), other attributes were added to give each polygon its Australian Standard Geographic Information Systems Geographic Data Interchange of feature-coded digital mapping data AS2482-1989 code and area in square metres and hectares, some default ArcInfo attributes were removed, the shapefile was uploaded to the Corporate Spatial Data Library as an ArcSDE layer, and in this layer, the width of the area code field was increased to allow island polygons to have the value "Island" assigned to this attribute instead of a missing value. 

Classification

Unclassified  

Attribute Quality

Comments

All attributes have been validated by the Habitat Ecology section, DPI, and are complete. 

Positional Accuracy

Comments

Grid cell boundary linework is generated from specific geographic coordinates which are based on divisions of 10 minutes in both latitude and longitude. A full description of the accuracy of the underlying shoreline data for the Tasmanian islands can be found in the GEODATA COAST100K 1992 Product User Guide available at http://www.ga.gov.au/data_download/docs/coast1992_userguide.pdf. You will need Adobe Acrobat Reader to view this document.. 

Conceptual Consistency

Comments

This data has been validated by the Habitat Ecology section, DPI. 

Missing Data

Comments

This layer is complete for the Victorian jurisdiction of the Bass Strait offshore fisheries 

Excess Data