Description of Maps

Click on one of the highlighted areas of the map or its title for further instructions on its usage.




Map Layer Descriptions
The layer list allows users to select which map layers are visible and active. The three drop down lists allow users to determine what information they would like to display by choosing the species, gear type, and year. The "Refresh Map" button updates the map after changes have been made to the layers or the selection criteria.

Layers
The check boxes are used to select which layers are visible. The radio buttons determine which layer is active and can be selected with the Identify tool.
Refresh Map
Click on Refresh Map button after making any changes to the layer selection or the observer data selection criteria.
Observer Data Options
Select the species, gear type or year from the drop down lists. Remember to refresh the map after making any changes to the observer data options criteria.
 


   
Map Legend Description
The map legend identifies the different types of objects that are displayed on the map.

Observer Data
The data in these maps comes from catches sampled by fishery observers on commercial fishing vessels. The data displayed are only from the sampled catches. Each cell in the map which has observer data is shaded to reflect the following scale: A black cell means the rate for the selected species fell in the upper 10 percentiles of all rates for that map; a grey cell means the rate either fell in the lower 90 percentiles or there was insufficient data to scale. As a convention, we decided there was insufficient data to scale when a species was found in less than 10 cells in the map.
Bathymetry
The 100 meter depth contour is displayed as a green line and the 200 meter as a blue line.
100 km2 Areas
The spatial resolution to which this observer data has been aggregated. The areas are displayed as a grid on a map.
NMFS Areas
NMFS areas used for managing the Alaskan groundfish fisheries. The Bering Sea management areas are green, Gulf of Alaska areas are yellow, and the Aleutian Islands areas are tan.
 


Tool Bar Descriptions
The tools of the tool bar are used to navigate around the map and select objects with the Identify tool.
Icon Name
Icon
Icon Description
Toggle between layer list and legend
Toggle between layer list and legend. The layer list identifies what layers are visible and/or active. A layer must be active in order to use the Identify tool to get the features attributes. The legend defines the symbols that are used on the map.
Zoom In
Zooms in on the map. Click once on the map to center the map on that location and zoom in on it by a fixed percentage, or click and drag over an area on the map to zoom in on that area .
Zoom out
Zooms out from the map. Click once on the map to center the map on that location and zoom out from it by a fixed percentage, or click and drag over an area on the map to zoom out from that area.
Zoom to full extent
Zooms out to the full extent of the map.
Zoom to last extent
Returns the map to the previous view.
Pan
Lets you pan the data in your map by dragging the display in any direction with the mouse. Move the cursor anywhere, hold down the left mouse button, and drag the display in any direction.
Identify
Click on a geographic feature to get its attributes. Clicking on one of the data points will bring up a table at the bottom of the window. The table will display the information associated with the data point.
Help
Click on this button to access a description of the map.


Attribute Table Description
The attribute table is used to display specific data about an object
on the map. Objects can be selected by using the Identify tool. When
selecting one of the colored rectangles that represent observer data
the attribute table will display the underlying data (see example below).


Column Name
Definition
Rec
 When viewing a map on which the "Zoom in" Tool has been used, a colored rectangle will often identify a single 100 km2 cell and will yield a single record (Rec = 1). If the "Zoom in" Tool has not been used, rectangles will overlap, and selecting a single point on the map may produce an attribute table containing many records. Each record in the table contains the data from a single 100 km2 cell but has a unique identifier associated with this table (i.e., Rec = 3 signifies that this is the third record in this specific table).
LAT100SQKM
 Latitude of the center of a 10 km x 10 km (100 km2) cell.
LON100SQKM
 Longitude of the center of a 10 km x 10 km (100 km2) cell.
GEAR
 NPT = non-pelagic trawl
PTR = pelagic trawl
POT = pot or trap
LGL = longline
YEAR
 Four digit year.
KG
 Estimated weight (in kilograms) of the sampled catches for this species, pooled by year, gear type, and 100 km2 cell.
RATE
 Estimated weight of the sampled catches for this species divided by the estimated weight of the sampled catches for all species, multiplied by 100.
The common name of the species or group.


Last Updated 18 - December - 2006