Kysttorsk eller skrei?

Kronikk i FiskeribladetFiskaren, mandag 15. juni 2009: s. 13 Gjengitt med tillatelse av FiskeribladetFiskare

Estimering av akustiske indekser med CV for torsk og hyse fra vintertoktet i Barentshavet 1994-2017 med Sea2Data programvaren StoX

Source at https://www.hi.no/publikasjoner/andre_publikasjoner/fisken_og_havet/2018/nb-no.English: The Sea2Data software StoX was applied to estimate acoustic indices with CVs for Northeast Arctic cod and haddock from the Barents Sea winter survey in 1994 to 2017. The indices are compared to indices previously estimated by the BEAM software. In most years the StoX indices for cod are quite similar to those obtained by BEAM, while they are somewhat higher for haddock. The largest deviations were mainly found for age groups with low indices and/or in years with raising of the indices.Norwegian: Sea2Data programmet StoX er brukt til å estimere akustiske indekser med CV for nordøstarktisk torsk og hyse fra vintertoktet i Barentshavet i 1994 til 2017. Indeksene er sammenlignet med indekser tidligere estimert med programmet BEAM. I de fleste år er StoX indeksene for torsk nokså like BEAM indeksene, mens de er noe høyere for hyse. De største forskjellene var hovedsakelig for aldersgrupper med lave indekser og/eller i år med skalering av indeksene

Estimation of acoustic indices with CVs for Northeast Arctic saithe in the Norwegian coastal survey 2003-2017 applying the Sea2Data StoX software

Source at http://hdl.handle.net/11250/2562514The Sea2Data software StoX was applied to estimate acoustic indices with CVs and length and weight at age for Northeast Arctic saithe from the Norwegian coastal survey Varanger - Stad in 2013 to 2017. The indices are compared to indices previously estimated by the BEAM software, and differences are mainly explained by different strata areas.Sea2Data programmet StoX er brukt til å estimere akustiske indekser med CV og lengde og vekt ved alder for nordøstarktisk sei fra det norske kysttoktet Varanger – Stad i 2013 til 2017. Indeksene er sammenlignet med indekser tidligere estimert med programmet BEAM, og forskjeller er i hovedsak forklart ved forskjeller i strata-areal

Trapped in the TAC Machine: Making a Fisheries-Based Indicator System for Coastal Cod in Steigen, Norway

acceptedVersio

Estimation of acoustic indices with CVs for cod and haddock in the Barents Sea winter survey 1994 – 2017 applying the Sea2Data StoX software.

Sea2Data programmet StoX er brukt til å estimere akustiske indekser med CV for nordøstarktisk torsk og hyse fra vintertoktet i Barentshavet i 1994 til 2017. Indeksene er sammenlignet med indekser tidligere estimert med programmet BEAM. I de fleste år er StoX indeksene for torsk nokså like BEAM indeksene, mens de er noe høyere for hyse. De største forskjellene var hovedsakelig for aldersgrupper med lave indekser og/eller i år med skalering av indeksene.publishedVersio

Acoustic abundance of saithe, coastal cod and haddock Finnmark - Møre Autumn 2009

Total echo abundance of saithe increased by 40 % compared to 2008 but is still among the lowest in the time series since 1992. The indices for all age groups were well below the average. The number of coastal cod increased for all age groups, except for the 2 years old. There are no signs of improved recruitment. It must be emphasized that the stock of coastal cod is for the time being at such a low level that the uncertainty in acoustic abundance estimation is relatively high

Acoustic abundance of saithe, coastal cod and haddock : Finnmark - Møre Autumn 2010

Total echo abundance of saithe decreased by 10 % compared to 2009 to the lowest level since 1997. The indices for all age groups except 3-year olds were well below the average. The number of coastal cod decreased for all age groups, except for 1-2 years old. There are only small signs of improved recruitment. The acoustic spawning stock biomass is at the same low level as in previous years

Spatial density distributions of fish, a balance between environmental and physiological limitation

Data (trawl, acoustic, CTD) from four scientific survey series , i.e. along the Norwegian coast, in the North Sea, and in the Barents Sea summer and winter, are used to describe and discuss the spatial density distributions of blue whiting, cod, haddock, redfish, saithe, capelin, and herring, in banks and shelf sea of depth mainly < 500 m, in relation to environmental conditions (depth, change of pressure, temperature, salinity, daylight, and physiological limitations). For cod, also information from data storage tags (DST) is used. For the demersal physoclists the relative vertical profiles are defined in terms of relative pressure reduction with reference to the pressure at the bottom. Thus vertical profiles with different bottom depth can be expressed in terms of free vertical range (FVR) and compared on a physiological basis. This restriction to rapid vertical movement is evident in the studied physoclist species. The acoustic sA-values show that blue whiting, haddock, saithe, cod, and redfish are mainly distributed within the bottom half of the water column, but also that they adapt to pelagic living. Haddock and blue whiting are more often found to distribute higher into the water column than saithe, cod, and redfish. Pelagic living is seen especially in areas with high acoustic sA-values and where the bottom is deeper than 200m. Day and night vertical profiles in terms of FVR are corrected for unequal day and night losses in the bottom acoustic dead zone. In most years, evidence of diurnal vertical migration for all seven species are found when day and night are clearly distinguishable. In many cases of demersal fish there is higher relative acoustic density in the mid-range of the bottom half of the water column at daytime than nighttime. At nighttime there is a degree of separation, one group of fish descends to aggregate near the seabed and another ascends