STELLER SEA LION ADULT COUNT DATABASE
             Last Update:  Sept. 20, 2001                                

The file  NMML.SSL.ZIP is a zip archive. To obtain the raw files it is necessary to unzip the
archive with a program such as pkzip, winzip, or zipwiz.  The archive contains the following
files: 

NMML.SSL.COUNTS.TXT    the data file, described in more detail below
NMML.SSL.README.TXT   a text version of this file
NMML.SSL.README.PDF    a pdf version of this file

The file NMML.SSL.COUNTS.TXT contains counts from Alaska of non-pup (adult and
juvenile) Steller sea lions in the NMML database.  The counts were made between 1904 and
2001.  This file includes counts obtained during breeding season aerial surveys, as well as counts
obtained during winter aerial surveys, boat surveys, cliff counts, and other miscellaneous counts.  

It is requested that users contact the director of the National Marine Mammal Laboratory before
using these data in publications. Please report errors to the Director:

          Director 
          National Marine Mammal Laboratory
          Alaska Fisheries Science Center
          7600 Sand Point Way NE
          Seattle, WA 98115-0070
          (206) 526 - 4049
This file is in ASCII text format.  It contains the following fields:

     SITE NAME
     REGION:     1 = California
              2 = Oregon
              3 = Washington
              4 = British Columbia, Canada
              5 = Southeast Alaska, 
              6 = Eastern Gulf of Alaska
              7 = Central Gulf of Alaska
              8 = Western Gulf of Alaska
              9 = Eastern Aleutian Islands
             10 = Central Aleutian Islands
             11 = Western Aleutian Islands
             12 = Bering Sea
             13 = Commander Islands
             14 = Kamchatka Peninsula
             15 = Kuril Islands
             16 = Sea of Okhotsk

     MONTH
     DAY
     YEAR

     COUNT  (Does not include newborn pups during the breeding season)
     PLATFORM:  1 = aerial photo count
                2 = count from the ground
                3 = count from a ship or skiff
                4 = visual estimate from the air
                9 = other (explain in comments)
               -9 = unknown or not specified
     SOURCE:    1 = NMFS/National Marine Mammal Laboratory
                2 = Alaska Department of Fish and Game
                3 = Oregon Department of Fish and Wildlife
                4 = Washington Department of Fish and Wildlife
                5 = NMFS/Southwest Fisheries Science Center
                6 = Canada Department of Fisheries and Oceans
                7 = other (explain in comments)
               -9 = unknown or not specified
     COMMENTS  (Clarification of PLATFORM, SOURCE, or COUNT as necessary)


DATA ISSUES

There are several issues with the data that users need to be aware of before using this database.

1.        This database is continually being updated and modified.  Users should check for the date
       the database was last modified.

2.        This data set includes counts from all times of year, some of which may not be appropriate
       for particular analyses.  The number of sea lions at a given site is extremely seasonally
       dependent. Comparison of counts from November in one year and from July in another
       year is likely to produce confounded results.  Population trend analyses typically are
       performed using data only from the breeding season   June and July.

3.        The most precise counts, and thus the counts preferred for population trend analyses, are
       aerial survey counts made from photographs.  Counts made from skiffs or ships may be
       very accurate for small numbers of sea lions but imprecise for large groups.  Visual
       estimates made from the air are best used as qualitative not quantitative data.

4.        In general, this database includes counts of non-pup (adult and juvenile) Steller sea lions. 
       This means that counts made during the breeding season (June and July) do not include
       newborn pups.  After pups undergo their first molt in the fall or early winter, however,
       they are the same color as older sea lions and they are difficult or impossible to
       distinguish from juveniles. 
       For this reason, counts made outside of the breeding season do include pups of the year
       that are 4 to 12 months old.

5.        A zero in the COUNT field means the site was surveyed and no sea lions were present.  If
       a site was not surveyed in a given year it is not included in the database;  there are no
       records with the COUNT field blank.

6.        Throughout the database "-9" indicates that a day, month, platform, or source is unknown.

7.        There are blanks in the COMMENT field.  This may cause problems when end users
       import the ASCII text file into their preferred software format.

8.        Site names are not consistent throughout the database.  Surveys prior to 1990 frequently
       combined separate haul-out sites on an island into a single count, whereas more recent
       surveys usually list sites separately (e.g., Agattu versus Agattu/Cape Sabak and
       Agattu/Gillon Point). Also, the NMML continues to refine the definition of individual
       sites and occasionally adds new sites.