Feeding of mature cod (Gadus morhua) on the spawning grounds in Lofoten

Many authors state that cod (Gadus morhua) do not feed during the spawning period. However, this more or less established fact has rarely been investigated in the field. Here, the content of stomachs from Northeast Arctic cod (NEAC) and Norwegian coastal cod (NCC) sampled from the spawning ground in Lofoten were examined over a 10-year period (1996–2006). The occurrence of food in the stomachs of spawning cod, stomach fullness, diet composition, and variation in these variables between NEAC and NCC, year, and sex were analysed and compared. The analysis shows that cod do feed, even when they are in a spawning state. NCC had a lower proportion of empty stomachs and the stomachs were fuller than those from NEAC. Females had a lower proportion of empty stomachs than males and their stomachs were in general fuller. Herring (Clupea harengus) dominated the diet of cod. However, cod consumption of herring on the spawning grounds seems to be a minor source of mortality on herring. Although spawning cod do feed, the proportion of empty stomachs was higher and stomach fullness was lower than in stomachs of NEAC from the Barents Sea

Atlantic cod (Gadus morhua)feeding over deep water in the high Arctic

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An evaluation of recruitment indices for Northeast Arctic cod (Gadus morhua L.)

Indices of the abundance of Northeast Arctic cod (Gadus morhua L.) for various life stages were compared in order to determine the earliest stage at .which year-class strength is established. The indices considered are: VPA estimates of spawning stock biomass; an egg abundance index; an early juvenile (approximately three-months old) abundance index; 0-group (age four to five months) abundance indices; bottom trawl and acoustic survey abundance indices for one, two and three- year-old cod and VPA estimates of the abundance of three-year-old cod. Based on a regression analysis, the relative abundance of early juvenile cod was the first life stage that was correlated with their relative'abundance as three year olds. Since the cokelation between the estimates of spawning stock biomass or total egg production and the relative abundance of three-year-old cod was weak, it is concluded that considerable yearly variation in mortality occurs before cod reach the early juvenile stage

Lifting back the waters: Marine geophysics provides new insights into the uThukela Banks Marine Protected Area

Using the first high-resolution geophysical data set collected from the uThukela Banks Marine Protected Area (MPA), we reveal a plethora of hitherto unknown or poorly resolved seabed features. In tandem with several remotely operated vehicle dives, we improve on the previous National Biodiversity Assessment map for the area and reveal a more complex picture of the seabed geology and geomorphology on which the MPA is predicated. The upper slope (-120 m and deeper) is dominated by small canyons, gullies and rills that occasionally extend to the shelf edge and form a series of slumps. Suspected cold-water corals were imaged on the interfluves of the Thukela Canyon. The mid to outer shelf (-60 to -100 m) is mostly rocky, and is composed of Pliocene-age siltstones for the most part. Aeolianite shorelines are found at depths of 60 m and 100 m, in which palaeo-lagoons and parabolic aeolian dune systems are also preserved. These features provide habitat for mesophotic corals and demersal fishes. Overlying and abutting hard rock substrates are unconsolidated sandy sediments that are mobilised by the inshore movement of the Agulhas Current. An inshore mud belt characterised by pockmarks associated with free gas expulsion is mapped for the first time. A well-developed palaeo-drainage pattern is also revealed, posing exciting new opportunities for the study of benthic communities associated with palaeo-estuaries and lagoons now exposed at the seabed. Several new habitats, both inside and out of the MPA boundaries, should form the basis for future research within the MPA, in addition to informing expansions of the MPA. Significance: Using a newly collected geophysical data set, we provide an unprecedented glimpse into the newly proclaimed uThukela Banks Marine Protected Area. We reveal a complexity of marine habitats hitherto unknown from previous biodiversity surveys. These habitats include areas of possible expansion given the recognition of keystone species that occur just outside the MPA limits

Environmental information for stock evaluation and management advice purposes

This report summarizes the work of an internal working group appointed by the Institute of Marine Research's management group to evaluate inclusion of environmental parameters in stock evaluation. The report discusses the current and potential usage of environmental information and presents specific recommendation on how to increase the usage of environmental information for stock evaluation and management advice purposes. NORSK SAMMENDRAG: Rapporten sammenfatter arbeidet til et utvalg nedsatt av ledergruppen ved Havforskningsinstituttet for å evaluere bruk av miljøinformasjon i bestandsvurdering og rådgivning. Rapporten diskuterer dagens- og potensiell bruk av miljøinformasjon og gir konkrete anbefalinger for hvordan Havforskningsinstituttet kan øke bruken av miljøinformasjon i bestandsvurderinger og rådgivning