scholarly journals Mixed stock origin of Atlantic bluefin tuna in the U.S. rod and reel fishery (Gulf of Maine) and implications for fisheries management

2020 ◽  
Vol 224 ◽  
pp. 105461
Author(s):  
Lisa A. Kerr ◽  
Zachary T. Whitener ◽  
Steven X. Cadrin ◽  
Molly R. Morse ◽  
David H. Secor ◽  
...  
2017 ◽  
Vol 74 (11) ◽  
pp. 1990-2004 ◽  
Author(s):  
Lisa A. Kerr ◽  
Steven X. Cadrin ◽  
David H. Secor ◽  
Nathan G. Taylor

Atlantic bluefin tuna (Thunnus thynnus) is currently managed as two separate eastern and western stocks, despite information indicating considerable stock mixing. Using a simulation model, we explored how scenarios of population-specific migration and uncertainty in aspects of bluefin tuna biology affect the magnitude, distribution, and mixed stock nature of the resource and catch of its associated fisheries. The analytical framework was a stochastic, age-structured, stock-overlap model that was seasonally and spatially explicit with movement of eastern- and western-origin tuna informed by tagging and otolith chemistry data. Alternate estimates of movement and assumptions regarding maturity and recruitment regime for western-origin fish were considered. Simulation of the operating model indicated considerable stock mixing in the western and central Atlantic, which resulted in differences between the stock and population view of western bluefin tuna. The relative biomass of the western population and its spatial and temporal distribution in the Atlantic was sensitive to model assumptions and configurations. Simulation modeling can provide a means to ascertain the potential consequences of stock mixing on the assessment and management of fishery resources.


<i>Abstract</i> .—The Gulf of Maine’s seafloor provides a wide array of valuable ecosystem services, including provision of habitat for commercially and ecologically important mammals, seabirds, fish, and invertebrates. Implementing ecosystem-based management will require improved information about the habitats of economically and ecologically important species and the impacts of different human activities, such as fish harvesting, offshore energy development, and shipping, to balance these competing needs. Currently, there is limited high resolution seabed substrate information in the Gulf of Maine, especially in the U.S. portion, because of the high cost of multi-beam echo sounder surveys. Moreover, this lack of coverage limits the ability of managers to use seafloor substrate information in ecosystem management activities, such as fisheries management, that require more holistic coverage of the bioregion. Therefore, the potential need for seafloor mapping in this region is enormous given the value of accurate seafloor information to managers in charge of minimizing impacts to and sustaining the ecosystem services provided by benthic habitat in the Gulf of Maine.


PLoS ONE ◽  
2013 ◽  
Vol 8 (9) ◽  
pp. e75480 ◽  
Author(s):  
Walter J. Golet ◽  
Benjamin Galuardi ◽  
Andrew B. Cooper ◽  
Molly E. Lutcavage

2007 ◽  
Vol 151 (6) ◽  
pp. 2063-2075 ◽  
Author(s):  
Jennifer Goldstein ◽  
Scott Heppell ◽  
Andrew Cooper ◽  
Solange Brault ◽  
Molly Lutcavage

Author(s):  
Gregory Neils Puncher ◽  
Alex Hanke ◽  
Dheeraj Busawon ◽  
Emma Sylvester ◽  
Walter Golet ◽  
...  

Identifying the origin of fish contained in a mixed fishery is critical for accurate stock assessments and the subsequent development of appropriate management strategies. Using a panel of 92 SNPs developed to differentiate Atlantic bluefin tuna (Thunnus thynnus) from the two main spawning areas (Gulf of Mexico and Mediterranean Sea), we used individual assignment to determine composition of feeding aggregations in the northwestern Atlantic Ocean (Gulf of Maine, Bay of Fundy, Scotian Shelf, Gulf of St. Lawrence, coastal Newfoundland). Among the 3,163 individuals collected between 2004 and 2018, we found that among lower age groups (<15 years) the spawning stock providing the most recruits to the Canadian fishery transitioned from Western Atlantic to Mediterranean origin over time. While the majority of older adults (>15 years) have consistently been of Western Atlantic origin, the disparity in the proportional contribution of western and eastern spawning groups narrowed significantly over the 14-year study period. Our results can be used to inform population-specific exploitation rates, improve stock assessments, identify age-dependent habitat use and areas suitable for additional conservation efforts.


2014 ◽  
Vol 98 (5) ◽  
pp. 1411-1430 ◽  
Author(s):  
John M. Logan ◽  
Walter J. Golet ◽  
Molly E. Lutcavage

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