An Interdisciplinary Assessment of Winter Flounder(Pseudopleuronectes americanus) Stock Structure

Abstract

Draft -has no official status with NOAA. WP#1 532 SDWG Background WP#1 May 2011 Stock Structure This information is distributed solely for the purpose of pre-dissemination peer review. It has not been formally disseminated by NOAA. It has no official status with the agency and does not represent final agency determination or policy. AbstractAn interdisciplinary review was undertaken to evaluate the stock structure and management of winter flounder (Pseudopleuronectes americanus) throughout its geographic range in the northwest Atlantic. Information on morphology, tagging studies, genetics, larval dispersal, life history traits, environmental signals and meristics was considered. In the coastal waters of the United States, winter flounder are managed as three separate units; Georges Bank, Gulf of Maine and Southern New England/Mid-Atlantic. In Canadian waters, winter flounder are managed as three units: western Scotian Shelf (NAFO Div. 4X), eastern Scotian Shelf (NAFO Div. 4VW), and the southern Gulf of St. Lawrence (NAFO Div. 4T). Estuarine spawning, which likely plays an important role in reproductive isolation and population structure, is non-existent on Georges Bank and Browns Bank, variable in more northern habitats and may be obligate in southern New England. Contingent groups are likely present in several regions, and merit further research. Despite evidence for local population structure, information from tagging, meristic analysis, and life history studies suggest extensive mixing within stock units, thereby supporting the current U.S. management regimen. Genetic analysis and parasite markers indicate that Canadian management units are distinct. However, examination of inshore and offshore winter flounder within division 4X suggests little interchange occurs between these groups. Based on their distribution and life history traits, several flounder stocks likely exist within the 4T management area. A stock composition analysis of mixed-stock fisheries would be useful to facilitate the management and assessment of winter flounder in both U.S. and Canadian waters.

Spatial and annual variation in fecundity and oocyte atresia of yellowtail flounder, Limanda ferruginea, in U.S. waters

“…Populations in these two regions, for both flounder species, are considered separate stocks. In the case of winter flounder, several phenotypic traits, including growth which influences fecundity, are consistent with genetic differentiation between SNE and GOM (DeCelles and Cadrin, 2011;Wirgin et al, 2014); however, genetic studies have provided inconclusive evidence for yellowtail flounder stock structure (Cadrin, 2010). Genetic structuring may be reduced for yellowtail flounder due to greater dispersal and mixing of pelagic eggs as compared to the benthic winter flounder egg.…”

Managing a Marine Stock Portfolio: Stock Identification, Structure, and Management of 25 Fishery Species along the Atlantic Coast of the United States

“…Some papers were easily found, whether in the gray literature (e.g., Cadrin et al 2004;NEFSC 2013) or the peer-reviewed literature (e.g., Waldman et al 1988Waldman et al , 1997DeCelles and Cadrin 2011). Many papers were only discovered by using an iterative approach with Boolean logic when searching the web (Eells et al 2012).…”

“…In the United States, three stocks are assessed, but this number has been higher in the past and life history variations exist within the coastal stocks. DeCelles and Cadrin (2011) summarized interdisciplinary evidence supporting stock structure, including meristic and morphometric data, parasite markers, little movement-particularly north to southinferred from tagging, and differences between growth and maturity. Common garden experiments demonstrate genetically based growth rate differences between stocks (Butts and Litvak 2007).…”

Investigating spatial variation and temperature effects on maturity of female winter flounder (Pseudopleuronectes americanus) using generalized additive models

“…areas is limited (Pereira et al 1999;DeCelles and Cadrin 2011), indicating a likelihood of locally adapted populations (e.g., differences in gene copy number and arrangement of antifreeze proteins; Hayes et al 1991). Given the broad latitudinal distribution of the species and limited movements of immature individuals, it is possible that fish within a region or subregion may be better adapted to local thermal environments (Everich and González 1977) or have different inherent capacities for growth (Butts and Litvak 2007;Kerr and Secor 2009;Bolton-Warberg et al 2013), obscuring the overall relationship between temperature and growth or maturation.…”