Exploratory Catch-at-Age Assessments of Gulf of Maine-Georges Bank Witch Flounder
| dc.contributor.author | Butterworth, Doug S | |
| dc.contributor.author | Rademeyer, Rebecca A | |
| dc.date.accessioned | 2017-03-07T09:58:51Z | |
| dc.date.available | 2017-03-07T09:58:51Z | |
| dc.date.issued | 2016-10 | |
| dc.description.abstract | Exploratory Statistical Catch-at-Age assessments of the Gulf of Maine-Georges Bank witch flounder stock indicate possibly unrealistically high q values (in the range of 3-5) for surveys, suggesting substantial herding by the net. If q is forced to be lower, the primary lack of fit that arises originates from the larger numbers of 11+ fish predicted compared to observed for the spring survey. All of treating the Albatross and Bigelow abundance index series as independent, including LPUE data, and forcing a lower value for q suggest the resource at present to be larger and of better status relative to pristine. Even if both the first two of these factors are incorporated, however, a strong retrospective pattern remains. During the meeting, a further base case run was developed to mimic the specifications agreed for the ASAP base case run as closely as possible, and some sensitivities to that also run. Of interest is that for a combination of the sensitivity factors (allowing selectivity doming, including LPUE data and downweighting the proportions-at-age data) the retrospective pattern is considerably reduced (especially for spawning biomass), the survey indices are fit better, and values of q drop, approaching 3. | en_ZA |
| dc.identifier.apacitation | Butterworth, D. S., & Rademeyer, R. A. (2016). <i>Exploratory Catch-at-Age Assessments of Gulf of Maine-Georges Bank Witch Flounder</i> University of Cape Town ,Faculty of Science ,Marine Resource Assessment and Management Group. Retrieved from http://hdl.handle.net/11427/24030 | en_ZA |
| dc.identifier.chicagocitation | Butterworth, Doug S, and Rebecca A Rademeyer <i>Exploratory Catch-at-Age Assessments of Gulf of Maine-Georges Bank Witch Flounder.</i> University of Cape Town ,Faculty of Science ,Marine Resource Assessment and Management Group, 2016. http://hdl.handle.net/11427/24030 | en_ZA |
| dc.identifier.citation | Butterworth, D.S. and Rademeyer, R.A. 2016. Appendix B3. Exploratory catch-at-age assessments of Gulf of Maine-Georges Bank witch flounder. Appendix to NEFSC SAW 62 Witch Flounder Working paper B1-B: Stock Assessment of Witch Flounder for 2016: 445-483 | en_ZA |
| dc.identifier.ris | TY - Working Paper AU - Butterworth, Doug S AU - Rademeyer, Rebecca A AB - Exploratory Statistical Catch-at-Age assessments of the Gulf of Maine-Georges Bank witch flounder stock indicate possibly unrealistically high q values (in the range of 3-5) for surveys, suggesting substantial herding by the net. If q is forced to be lower, the primary lack of fit that arises originates from the larger numbers of 11+ fish predicted compared to observed for the spring survey. All of treating the Albatross and Bigelow abundance index series as independent, including LPUE data, and forcing a lower value for q suggest the resource at present to be larger and of better status relative to pristine. Even if both the first two of these factors are incorporated, however, a strong retrospective pattern remains. During the meeting, a further base case run was developed to mimic the specifications agreed for the ASAP base case run as closely as possible, and some sensitivities to that also run. Of interest is that for a combination of the sensitivity factors (allowing selectivity doming, including LPUE data and downweighting the proportions-at-age data) the retrospective pattern is considerably reduced (especially for spawning biomass), the survey indices are fit better, and values of q drop, approaching 3. DA - 2016-10 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 2016 T1 - Exploratory Catch-at-Age Assessments of Gulf of Maine-Georges Bank Witch Flounder TI - Exploratory Catch-at-Age Assessments of Gulf of Maine-Georges Bank Witch Flounder UR - http://hdl.handle.net/11427/24030 ER - | en_ZA |
| dc.identifier.uri | http://hdl.handle.net/11427/24030 | |
| dc.identifier.vancouvercitation | Butterworth DS, Rademeyer RA. Exploratory Catch-at-Age Assessments of Gulf of Maine-Georges Bank Witch Flounder. 2016 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/24030 | en_ZA |
| dc.language | eng | en_ZA |
| dc.publisher.department | Marine Resource Assessment and Management Group | en_ZA |
| dc.publisher.faculty | Faculty of Science | en_ZA |
| dc.publisher.institution | University of Cape Town | |
| dc.rights | Creative Commons Attribution 4.0 International (CC BY 4.0) | * |
| dc.rights.uri | http://creativecommons.org/licenses/by/4.0/ | en_ZA |
| dc.title | Exploratory Catch-at-Age Assessments of Gulf of Maine-Georges Bank Witch Flounder | en_ZA |
| dc.type | Working Paper | en_ZA |
| uct.type.filetype | Text | |
| uct.type.filetype | Image | |
| uct.type.publication | Research | en_ZA |
| uct.type.resource | Working paper | en_ZA |