Changes in the Distribution of Atlantic Bluefin Tuna (Thunnus thynnus) in the Gulf of Maine 1979-2005

Resource type
Date created
2013
Authors/Contributors
Abstract
The Gulf of Maine, NW Atlantic Ocean, is a productive, seasonal foraging ground for Atlantic bluefin tuna (Thunnus thynnus), but commercial landings of adult size classes were up to 40% below the allocated total allowable catch between 2004 to 2008 for the rod and reel, harpoon, and purse seine categories in the Gulf of Maine. Reduction in Atlantic bluefin tuna catches in the Gulf of Maine could represent a decline in spawning stock biomass, but given wide-ranging, complex migration patterns, and high energetic requirements, an alternative hypothesis is that their dispersal patterns shifted to regions with higher prey abundance or profitability, reducing availability to U.S. fishing fleets. This study fit generalized linear models to Atlantic bluefin tuna landings data collected from fishermen’s logbooks (1979-2005) as well as the distances between bluefin tuna schools and Atlantic herring (Clupea harengus), a primary prey species, to test alternative hypotheses for observed shifts in Atlantic bluefin tuna availability in the Gulf of Maine. For the bluefin model, landings varied by day of year, latitude and longitude. The effect of latitude differed by day of year and the effect of longitude differed by year. The distances between Atlantic bluefin tuna schools and Atlantic herring schools were significantly smaller (p<0.05) than would be expected from a randomly distributed population. A time series of average bluefin tuna school positions was positively correlated with the average number of herring captured per tow on Georges Bank in spring and autumn surveys respectively (p<0.01, r2=0.24, p<0.01, r2=0.42). Fishermen’s logbooks contributed novel spatial and temporal information towards testing these hypotheses for the bluefin tuna fishery.
Document
Identifier
DOI: 10.1371/journal.pone.0075480
Published as
Golet WJ, Galuardi B, Cooper AB, Lutcavage ME (2013) Changes in the Distribution of Atlantic Bluefin Tuna (Thunnus thynnus) in the Gulf of Maine 1979-2005. PLoS ONE 8(9): e75480. doi:10.1371/journal.pone.0075480
Publication title
PLoS ONE
Document title
Changes in the Distribution of Atlantic Bluefin Tuna (Thunnus thynnus) in the Gulf of Maine 1979-2005
Date
2013
Volume
8
Issue
9
Publisher DOI
10.1371/journal.pone.0075480
Copyright statement
Copyright is held by the author(s).
Scholarly level
Peer reviewed?
Yes
Language
Attachment Size
tuna.pdf 2.88 MB