Although thereexistsanEU-Norwaylong-termmanagementplanforNorthSeasaithe,includingacatch
regulation, thespawningstockbiomasshasdeclinedinthelastfewyears,recruitmenthasbeenbelow
averagesince2006andgrowthratesarelow.Moreover,catchratesusedasaproxyofstockabundance
in stockassessment,arebelievedtodeclinemuchmoreslowlythantheactualstockabundance.Thus,
a quota-basedsystemmaynotbesufficient tosustainthestock.Abio-economicsimulationand
optimisation modelwasusedtoexplorehowvariousareaclosuresincombinationwiththequota-
systemaffectlevelsofby-catch,netprofit ofindividual fleet segmentsfromdifferentports,andstock
development inthat fishery.Testedareaclosuresdifferedinduration,sizeandlocationrelativetomajor
ports andtoseasonalmovementpatternsofspecies.Theseclosuresweretestedundervariable
recruitment. Areaclosuresthatwerecoveringtheseasonalmigrationrouteofsaitherevealedalmost
two timesgreaterincreasesinspawningstockbiomassthanclosuresthatwerenotcoveringthe
migration route.Evenareaclosureswhereahighdispersalrateofindividualswasassumedresultedin
increased spawningstockbiomassofsaithe.Benefits ofthetestedareaclosuresweredistributed
heterogeneouslyamongindividual fleet segments.Increasesofsaithestocksizewereoffsetbyincreases
in codby-catch.Thelocationofanareaclosurerelativetothehomeportof fleet segmentsdecidedif
steaming costsincreasedandcatchesdecreased.