Thanks for posting this Mike. Sounds like we have some good scientists asking some good questions.
I can answer a couple as I worked on the research cruises and as a port sampler for NMFS.
"Tobe productive, the participants in the upcoming meeting must have a thorough understanding of the raw data and the data analysis that are conducted prior to numerical modeling of the stock," they pointed out.
This is very true. They also need to know the metadata around which the raw data was collected.
"Wehave been unable to determine from the information provided any details on the quality of the data used for the age-length
relationship," they added. "What data are used? Are the number of samples for landings sufficient over the time series?
The data used comes from two sources.
1. Research cruises which make random, half hour tows with a ground fish net which has a fine mesh bag.
2. Port agents now called field agents and port samplers who go to the commercial fish dealers and collect age length samples shore side. The way that works is Woods Hole the NEFSC (North East Fishery Science Center) makes annual quarterly requests by species and market category by stock area. For example they will ask for 25 jumbo, 25 lg, and 25 medium fluke from statistical area 616. The port samplers will do their very best to collect every sample they are asked for.
The issue I have w/ the cruises is they must use the same net for everything, I understand why, but fluke (especially big fluke) can surf the pressure wave in front of the net easily for half and hour and never be caught. You surfers know how the big board works.
The issue I have w/ port samplers is the number of field offices which have been closed down; Rockland ME, Boston MA, Woods Hole MA, Newport RI, Sandy Hook NJ, Ocean City MD, Greenbackville VA, and one in NC.
"Are the sexes differentiated in modeling the age structure of the population? If not, is this considered a significant uncertainty?"
Samples taken on research cruises are sexed during dissection. Samples taken by port agents are not. Unlike yellow tail flounder you can't candle the fish to get the sex, they must be cut.
I can answer a couple as I worked on the research cruises and as a port sampler for NMFS.
"Tobe productive, the participants in the upcoming meeting must have a thorough understanding of the raw data and the data analysis that are conducted prior to numerical modeling of the stock," they pointed out.
This is very true. They also need to know the metadata around which the raw data was collected.
"Wehave been unable to determine from the information provided any details on the quality of the data used for the age-length
relationship," they added. "What data are used? Are the number of samples for landings sufficient over the time series?
The data used comes from two sources.
1. Research cruises which make random, half hour tows with a ground fish net which has a fine mesh bag.
2. Port agents now called field agents and port samplers who go to the commercial fish dealers and collect age length samples shore side. The way that works is Woods Hole the NEFSC (North East Fishery Science Center) makes annual quarterly requests by species and market category by stock area. For example they will ask for 25 jumbo, 25 lg, and 25 medium fluke from statistical area 616. The port samplers will do their very best to collect every sample they are asked for.
The issue I have w/ the cruises is they must use the same net for everything, I understand why, but fluke (especially big fluke) can surf the pressure wave in front of the net easily for half and hour and never be caught. You surfers know how the big board works.
The issue I have w/ port samplers is the number of field offices which have been closed down; Rockland ME, Boston MA, Woods Hole MA, Newport RI, Sandy Hook NJ, Ocean City MD, Greenbackville VA, and one in NC.
"Are the sexes differentiated in modeling the age structure of the population? If not, is this considered a significant uncertainty?"
Samples taken on research cruises are sexed during dissection. Samples taken by port agents are not. Unlike yellow tail flounder you can't candle the fish to get the sex, they must be cut.