Capt_Keith
Site Admin
Joined: Apr 02, 2009
Posts: 3141
Location: Myrtle Beach SC
|
 Posted: Sat Feb 04, 2012 9:48 pm Post subject: New Method Improves Catch Estimates |
 |
|
WHAT IS NOAA’S NEW METHOD AND WHY WAS IT DEVELOPED?
Case Study 3
South Atlantic Black Sea Bass
Properly accounting for zero-catch trips
The change
2004-2010 estimates for black sea bass catch in South Carolina were about 1.4 million fish lower using the improved MRIP estimation methodology as opposed to MRFSS.
Finding and fixing the bias
When we analyzed the difference between the two estimates, we found that the changes were again due to the oversampling of angler fishing trips at high-activity sites. In this case, the oversampling led to an effective undercount of “zero-catch” trips for black sea bass.
That’s because trips sampled at high-activity sites showed a higher probability of catching black sea bass. Trips with no catch of black sea bass were more common at low-activity sites.
Since we sampled more heavily at high-activity sites, this caused the MRFSS estimator of average angler catch of this species to be biased high. In reality, there were more trips that did not catch black sea bass than the MRFSS estimates showed.
The bottom line To produce accurate estimates, once again it was necessary to down-weight the catch data collected at high-activity sites.
_________________
Admin of southcarolina-offshore.com
Captain Keith
Cell: 843-907-0064
www.NorthMyrtleBeachFishingCharters.com
www.feedinfrenzycharters.com
www.southchathamtackle.com
www.BarefootFishing.net
www.fishfindertackle.com |
|
Forum FAQ
Search
Usergroups
Profile
Log in to check your private messages
Log in
