Recent Advances in Sea-Urchin Aquaculture in Norway

Sea-urchin aquaculture (echiniculture) in Norway is being developed along two sep a rate paths with some overlap. Bodø University College (HBO) is pursuing a strategy of full domestication, with the explicit goal of bringing the en tire production cycle of the sea urchin under a controlled industrial regime, whereas the Norwegian Institute of Fisheries and Aquaculture Research (NIFA) is developing techniques for gonad enhancement of wild urchins using for mulated feed. Both institutions focus their R&D efforts on the green sea urchin, Strongylocentrotus droebachiensis. The closely related species S. pallidus is also being investigated at HBO, as it appears to be largely resistant to infection by the parasitic nematode Echinomermella matsi.(1) Nematode infection is easy to prevent in land-based echiniculture facilities using hatchery-reared juveniles, but all sea-based urchin aquaculture in northern Norway is susceptible to infection by E. matsi. S. pallidus is, therefore, targeted as an integral part of an ongoing effort to develop a disease-resistant sea-urchin variety suitable for both land-based and sea-based echiniculture.(2

Live holding of red king crab (Paralithodes camtschaticus) and snow crab (Chionoecetes opilio) — Effect on microbial growth in processed leg meat during refrigerated storage

The red king crab (RKC, Paralithodes camtschaticus) and snow crab (SC, Chionoecetes opilio) are valuable decapods that can undergo live holding (LH) in onshore facilities before either live export or processing into two cooked-frozen sections (i.e., clusters). This study investigated the effect of the LH time (up to two months without feeding) and temperature (5│10 °C for RKC; 1│5 °C for SC) on the total viable psychrotrophic count (TVCP) and Pseudomonas spp. in the leg meat of cooked RKC and SC. The effect of freezing after cooking was also evaluated. The counts were determined during storage at 4 °C after cooking on the clusters undergoing either immediate refrigeration (IR) or 24-month frozen storage before refrigeration (FBR). In the RKC cooked leg meat, the LH temperature significantly affected the TVCP, with LH at 10 °C leading to higher counts, while the Pseudomonas spp. levels were mainly influenced by the freezing, with lower levels in FBR samples compared to their IR counterparts. In the SC cooked leg meat, the LH conditions did not significantly affect the counts, which were instead significantly lowered by the freezing. From an industrial and commercial standpoint, it can be concluded that LH of RKC at high temperature (10 °C) led to a shorter microbial shelf-life of cooked RKC clusters, with the clusters undergoing FBR showing longer microbial shelf-life than their IR counterparts. By contrast, with the mild cooking regime applied, the LH time and temperature of SC had a lower influence on the microbial shelf-life of cooked SC clusters than that given by the choice of the storage type (IR or FBR) after cooking.publishedVersio

Evaluation of Morphological and Quality Parameters in Adult Male Red King Crabs (Paralithodes camtschaticus) Raised to Commercial Weight from Juveniles

Red king crab (RKC) has become a valuable resource, and most of this fishery operates in a quota-regulated area (QRA) east of 26°E. West of the QRA, a free fishery area (FFA) is established to limit further migration. Today, juvenile RKCs from the FFA are not utilized. This study investigated morphological and quality parameters in adult RKCs (≥800 g) after live holding (LH) of 23 months starting from juveniles (on average 500 g). During the LH, the RKCs were kept in two separate tanks, one at ambient seawater temperature (AST) and one at elevated seawater temperature (AST-E). The RKCs were fed ad libitum. Both tanks were divided into two sections, one with a sand tray. After 23 months, the RKCs were processed and analyzed. The hepatosomatic index, abdomen index, meat content, cluster yield, moisture, whiteness index, and instrumental chewiness differed significantly () between the wild RKCs and the RKCs from one or both LH groups. The availability of sand indicated improved habitat conditions as several parameters were positively affected. Also, lower variation in morphology and quality parameters of the processed muscle was observed in RKCs from the subgroups with access to sand than those without sand.Evaluation of Morphological and Quality Parameters in Adult Male Red King Crabs (Paralithodes camtschaticus) Raised to Commercial Weight from JuvenilespublishedVersio

Arctic charr farming

The Arctic charr (Salvelinus alpinus L.) is a holarctic salmonid fish species with both landlocked and anadromous populations. In Scandinavia it is mainly found in the mountain area, but it also appears in deep and large lake further south, i.e. in the Alps. It is the northernmost freshwater fish and A. charr is generally regarded as the most cold-adapted freshwater fish. A. charr has been commercially farmed since the early 90ths and today, the total production is 3000, 2300 and 700 tonnes/year in Iceland, Sweden and Norway, respectively. Both in Sweden and Iceland, there are selective breeding programs in effect and the bulk of the farming production is conducted using offspring from the national breeding programs in each country. A. charr is renowned for its ability of high growth rate at low temperature and is therefore especially suitable for farming at high latitudes and altitudes. Moreover, due to the success of the breeding programs, the charr used in farms today grow faster and mature at a larger size and age than the original wild charr. Hence, although being a fairly small industry at present, A. charr farming is predicted to grow in all three countries. This booklet summarises up-to-date knowledge on A. charr farming production cycle, from brood stock to juvenile on-growing stage (Fig. 1). It is intended to be useful for people taking their first steps in A. charr culture but also to serve as a farming manual for more experienced farm staff. Therefore, the booklet is divided in to two chapters. The first chapter (Arctic charr farming in practice) provides a straight forward introduction to each production step from brood stock to juveniles. The second chapter (theory and background) presents some details and research data on the background of specific farming practices and procedures

Catches in abandoned snow crab (Chionoecetes opilio) pots in the Barents Sea

During a 2018 retrieval cruise for abandoned snow crab (Chionoecetes opilio) pots in the Barents Sea, approximately 8600 pots abandoned 1.5 years earlier were recovered. Forty-three percent of a subsample of 1000 pots contained snow crabs, with an average of three crabs per pot. Most of the crabs were alive (~98%) and dominated by large males. Pinch injuries and limb loss were common and tended to decline with increasing crab size. Reflex testing showed that the crabs were vital (i.e. the crabs moved their legs, chelipeds and maxillipeds when stimulated), which was supported by a relatively high meat content. However, energy reserves in the digestive glands (hepatopancreas reserves) were low, indicating overall energy deficiencies. Our results indicate considerable unaccounted mortality due to self-baiting, continued catch and cannibalism. The findings demonstrate that snow crab pots which are lost or abandoned in the Barents Sea fishery maintain huge potential for ghost-fishing impacts.publishedVersio

Evaluering av ulike agn til snøkrabbefiske i Barentshavet

Akkar og sild er de vanligste agnene som blir brukt under snøkrabbefiske i Barentshavet i dag. Ut fra økonomiske og etiske betraktninger er det viktig å erstatte dagens agn med alternative restråstoffkilder som har liten alternativ bruk. Målet med prosjektet var derfor å teste ut alternative råstoffkilder som er billigere og mindre egnet til humant konsum. Forsøkene viser at det er mulig å få like god fangst ved bruk av innmat fra torsk som ved bruk av akkar, som regnes for å være det beste agnet til snøkrabbe i dag.publishedVersio

Improving size selection in the Norwegian red king crab (Paralithodes camtschaticus) fishery through modification to pot design and soak time.

Red king crab (Paralithodes camtschaticus) represent a valuable inshore fisheries resource for communities in northern Norway. The fishery is regulated east of the 26th meridian by vessel quotas and a minimum landing size of 130 mm carapace length. It is executed using baited pots that must be fitted with circular escape openings. Despite this, pot catches typically contain a large proportion of sub-legal sized crab. This implies increased labor-intensive sorting which can lead to crab becoming injured, loosing limbs or delayed mortality. Such consequences negatively impact the sustainability of the fishery. In this study, we examined the potential of two new pot designs and longer soak times to reduce undersized crab catches in comparative field trials. A design consisting of a tarpaulin panel on the pot entrance (intended to prevent undersized individuals from gaining traction and entering) was found to be no better at reducing undersized catches than the currently used commercial design fitted with escape openings. A second design with a baited lower chamber (which could be accessed through the pot floor via escape openings) was intended to motivate undersized crab to escape more readily. If fished commercially, any crab in the bottomless lower chamber would be left behind on the seabed upon hauling. This design was found to have minimal effects on sublegal catches. However, increasing the soak time of the currently used commercial design from 1 day to 4 days reduced undersized crab catches substantially. This effect is likely related to bait becoming exhausted over time, thereby increasing the opportunity and motivation of sublegal crab to find and exit the pot through the mandatory escape openings. Laboratory-based behavioural observations using the panel design indicated that entry was dependent on crab orientation and that crab were less successful at entering than for the commercial design. However, all sizes of crab used an unintentional fold in the panel to increase their entrance probability. This may explain the lack of success of this design during the field trials. We conclude that ensuring bait is exhausted by employing longer soak times than is typically used by fishers would reduce catches of undersized crab in the fishery.publishedVersio

De novo transcriptome assemblies of red king crab (Paralithodes camtschaticus) and snow crab (Chionoecetes opilio) molting gland and eyestalk ganglia - Temperature effects on expression of molting and growth regulatory genes in adult red king crab

Red king crab (Paralithodes camtschaticus) and snow crab (Chionoecetes opilio) are deep-sea crustaceans widely distributed in the North Pacific and Northwest Atlantic Oceans. These giant predators have invaded the Barents Sea over the past decades, and climate-driven temperature changes may influence their distribution and abundance in the sub-Arctic region. Molting and growth in crustaceans are strongly affected by temperature, but the underlying molecular mechanisms are little known, particularly in cold-water species. Here, we describe multiple regulatory factors in the two high-latitude crabs by developing de novo transcriptomes from the molting gland (Y-organ or YO) and eye stalk ganglia (ESG), in addition to the hepatopancreas and claw muscle of red king crab. The Halloween genes encoding the ecdysteroidogenic enzymes were expressed in YO, and the ESG contained multiple neuropeptides, including molt-inhibiting hormone (MIH), crustacean hyperglycemic hormone (CHH), and ion-transport peptide (ITP). Both crabs expressed a diversity of growth-related factors, such as mTOR, AKT, Rheb and AMPKα, and stress-responsive factors, including multiple heat shock proteins (HSPs). Temperature effects on the expression of key regulatory genes were quantified by qPCR in adult red king crab males kept at 4 °C or 10 °C for two weeks during intermolt. The Halloween genes tended to be upregulated in YO at high temperature, while the ecdysteroid receptor and several growth regulators showed tissue-specific responses to elevated temperature. Constitutive and heat-inducible HSPs were expressed in an inverse temperature-dependent manner, suggesting that adult red king crabs can acclimate to increased water temperatures.publishedVersio

The improvement of size selection in red king crab traps

I dag brukes det utelukkende sammenleggbare en-kammerteiner for fangst av kongekrabbe på Finnmarkskysten. Det er ingen krav om å bruke rømningsveier i teinene, men fiskerne bruker likevel rømningsveier for å prøve å selektere ut undermålskrabbe. Målet i dette prosjektet var å dokumentere effektiviteten av et ekstra seleksjonskammer sydd inn i tradisjonelle krabbeteiner, som kun undermålskrabbe hadde tilgang til. Forsøkene viste at det er mulig å forbedre seleksjon i dagens teiner. Ca. 50 % av undermålskrabbene ble «fanget» i seleksjonskammeret på det beste. I tillegg til å jobbe med to-kammerløsning, bør man også jobbe videre med alternative fluktåpninger og utforming av fluktåpning som tillater undermåls krabber å rømme ut av teinen uten å komme seg inn igjen fra dagens en-kammerteine. Det bør også jobbes med å gjøre inngangspartiet på dagens krabbeteiner mer rømningssikker, da krabber av kommersiell størrelse i dag lett kommer seg ut av inngangspartiet.The improvement of size selection in red king crab trapspublishedVersio

Montana Kaimin, May 1, 2002

Student newspaper of the University of Montana, Missoula.https://scholarworks.umt.edu/studentnewspaper/10663/thumbnail.jp