Depths in the logbook system
On the pre 1997 logbook form it was possible to record up to 4 depths values per tow. Net- and Bottom depth, both for set and up position.
Of these CDFW and ODFW only recorded the bottom and net depth at set time, whereas WDFW recorded only one of bottom/net (need to confirm) depths at set and up time, then recorded the lesser one as min_depth and the greater one as max_depth, in an attempt to account for tows fishing over a range of depths.
On the form in use since 1997 there is only one depth value to be recorded (average depth) which the fisherman is supposed to assign the depth the majority of the fish was caught at.
However both ODFW and WDFW still report two depths. Mark Freeman (ODFW) said that the average depth is just put into the bottom-depth field in the ODFW database, and forwarded as such to PacFIN (most of the net_depth's are zero for 1997 and later). Also, according to Mark Freeman, the switch-over from the the old form to the new one was not instantaneous, so that for a time both forms were in use simultaneously (accouting for the few instances were a non zero net depth was supplied after 1996). So for 1997 and 1998 what is sent to PacFIN as bottom depth might originally have been average depth or bottom depth at set.
For WDFW data most records have non-zero data for both depths since 1997, a growing part of those have the same value for min and max though, (more in 1997 than 96, and even more in 98). So for WDFW data average depth is put into both the min_depth and max_depth fields, and submitted to PacFIN. As is the case in Oregon, old, pre 1997 forms were still in circulation in 1997 and 1998 and resulted in actual min_depth and max_depth being put into those fields as well.
The above leaves us with the following depths
| depth | reported by |
|---|---|
| bottom_depth at set | CDFW and ODFW before 1997 |
| net_depth at set | CDFW before 1997, ODFW up to present |
| min(set,up) | WDFW before 1997 |
| max(set,up) | WDFW before 1997 |
| something called mindepth | WDFW since 1997 |
| something called maxdepth | WDFW since 1997 |
| average depth | CDFW since 1997 |
| something called btm_depth | ODFW since 1997 |