Abstract: In order to forage and to provision offspring effectively, seabirds negotiate a complex of behavioural, energetic, environmental and social constraints. In first tests of GPS loggers with seabirds in North America, we investigated the foraging tactics of free-ranging northern gannets (Sula bassana) at a large and a medium-sized colony that differed in oceanography, coastal position and prey fields. Gannets at Low Arctic colony (Funk Island) 50 km off the northeast coast of Newfoundland, Canada provisioned chicks almost entirely with small forage fish (capelin Mallotus villosus, 89%), while at boreal colony (Bonaventure Island) 3 km from shore in the Gulf of St. Lawrence, Quebec, Canada, large pelagic fish dominated parental prey loads (Atlantic mackerel Scomber scombrus 50%, Atlantic herring Clupea harengus 33%). Mean foraging range and the total distance travelled per foraging trip were significantly greater at the larger inshore colony (Bonaventure) than at the smaller offshore colony (Funk Island; 138 and 452 km vs. 64 and 196 km, respectively). Gannets from Funk Island consistently travelled inshore to forage on reproductive capelin shoals near the coast, whereas foraging flights of birds from Bonaventure were much more variable in direction and destination. Birds from the Low Arctic colony foraged in colder sea surface water than did birds from the boreal colony, and dive characteristics differed between colonies, which is concordent with the difference in prey base. Differences between the colonies reflect oceanographic and colony-size influences on prey fields that shape individual foraging tactics and in turn generate higher level colony-specific foraging “strategies”.

Abstract: Recruitment variability caused by density-dependent and density-independent processes is an important area within the study of fish dynamics. These processes can exhibit nonlinearities and nonadditive properties that may have profound dynamic effects. We investigate the importance of population density (i.e., density dependence) and environmental forcing (i.e., density independence) on the age-0 and age-1 abundance of capelin (Mallotus villosus), northeast Arctic cod (Gadus morhua), northeast Arctic haddock (Melanogrammus aeglefinus), and Norwegian spring spawning herring (Clupea harengus) in the Barents Sea. We use statistical methods that explicitly account for nonlinearities and nonadditive interactions between internal and external variables in the abundance of these two pre-recruitment stages. Our results indicate that, during their first five months of life, cod, haddock, and herring experience higher density-dependent survival than capelin. The abundance of age-0 cod depends on the mean age and biomass of the spawning stock, a result which has implications for the management of the entire cod stock. Temperature is another important factor influencing the abundance at age-0 and age-1 of all four species, except herring at age-1. Between age-0 and age-1, there is an attenuation of density-dependent survival for cod and herring, while haddock and capelin experience density dependence at high and low temperatures, respectively. Predation by subadult cod is important for both capelin and cod at age-1. We found strong indications for interactions among the studied species, pointing to the importance of viewing the problem of species recruitment variability as a community, rather than as a population phenomenon.

Abstract: This is the first study on the emergent properties for empirical ecosystem models that have been validated by time series information Ecosystem models of the western and central Aleutian Islands and Southeast Alaska were used to examine indices of ecosystem status generated from network analysis and incorporated into Ecopath with Ecosim Dynamic simulations of the two ecosystems over the past 40 years were employed to examine if these indices reflect the dissimilar changes that occurred in the ecosystems The results showed that the total systems throughput (TST) and ascendancy (A) followed the climate change signature (Pacific decadal oscillation, PDO) in both ecosystems, whereas the redundancy (R) followed the inverse trend The different trajectories for important species such as Steller sea lions (Eumetopias jubatus), Atka mackerel (Pleurogrammus monopterygius), pollock (Theragra chalcograma), herring (Clupea pallasii), Pacific cod (Gadus macrocephalus) and halibut (Hippoglossus stenolepis) were noticeable in the Finn cycling index (FCI), entropy (H) and average mutual information (AMI): not showing large change during the time that the Stellers sea lions, herring, Pacific cod, halibut and arrowtooth flounder (Atheresthes stomias) increased in Southeast Alaska, but showing large declines during the decline of Steller sea lions, sharks, Atka mackerel and arrowtooth flounder in the Aleutians On the whole, there was a change in the emergent properties of the Aleutians around 1976 that was not seen in Southeast Alaska Conversely, the emergent properties of both systems showed a change around 1988, which indicated that both systems were unstable after 1988

Abstract: Pacific herring were susceptible to waterborne challenge with viral haemorrhagic septicaemia virus (VHSV) throughout their early life history stages, with significantly greater cumulative mortalities occurring among VHSV-exposed groups of 9-, 44-, 54- and 76-day-old larvae than among respective control groups. Similarly, among 89-day-1-year-old and 1+year old post-metamorphosed juveniles, cumulative mortality was significantly greater in VHSV-challenged groups than in respective control groups. Larval exposure to VHSV conferred partial protection to the survivors after their metamorphosis to juveniles as shown by significantly less cumulative mortalities among juvenile groups that survived a VHS epidemic as larvae than among groups that were previously naive to VHSV. Magnitude of the protection, measured as relative per cent survival, was a direct function of larval age at first exposure and was probably a reflection of gradual developmental onset of immunocompetence. These results indicate the potential for easily overlooked VHS epizootics among wild larvae in regions where the virus is endemic and emphasize the importance of early life history stages of marine fish in influencing the ecological disease processes.

Abstract: Summary The concentrations of the non-volatile and volatile amines that formed in herring (Clupea harengus) and haddock (Melanogrammus aeglefinus) during storage as fillets and as whole fish in ice and at 5°C were determined. Comparison of the rates of formation of the major non-volatile amines (histamine, cadaverine and putrescine) and trimethylamine showed that haddock fillets deteriorated more rapidly than the whole gutted fish and that ungutted herring spoiled more rapidly than fillets. The value of amines as indices of spoilage in fish is discussed.

Abstract: The use of washed cod light muscle minces in mechanistic studies of hemoglobin (Hb)-mediated fish lipid oxidation has largely increased in the past 5 years. Although cod light muscle has a low level of intrinsic lipid oxidation catalysts, a prerequisite for a good oxidation model system, we believe it cannot fully mimic the oxidation kinetics taking place in other fish species being more susceptible to lipid oxidation. The aim of this study was to systematically investigate whether washed mince model systems useful in Hb-mediated oxidation studies could be prepared also from herring (Clupea harengus) and salmon (Salmo salar) light muscles. The kinetics of oxidation in the washed models was measured during ice storage (+/-Hb), and the results were related to compositional differences. Minces from cod, herring, and salmon light muscles were washed 3 times with 3 volumes of water and buffer. A 20,mu M portion of Hb and 200 ppm streptomycin was then added, followed by adjustment of pH and moisture to 6.3 and 86%, respectively. Samples with or without Hb were then stored on ice, and oxidation was followed as peroxide value (PV), rancid odor, redness (a*) loss and yellowness (b*). Prior to storage, all minces and models were also analyzed for total lipids, fatty acids, a-tocopherol, proteins, Hb, Fe, Cu, and Zn. Hb-mediated lipid oxidation appeared within 2 days on ice in all models. Small differences in the oxidation rates ranked the models as herring > cod > salmon. These differences were ascribed to more preformed peroxides and trace elements in the herring model, and more antioxidants in the salmon model. Controls, without Hb, stayed stable in all cases except herring, where a very slight oxidation appeared, especially if the herring raw material had been prefrozen. In conclusion, fattier fish like dark muscle species and salmonoids are useful for making washed mince model systems and would be a better choice than cod if there is an interest in the oxidation kinetics of such species.

Abstract: Echolocation clicks from Norwegian killer whales feeding on herring schools were recorded using a four-hydrophone array. The clicks had broadband bimodal frequency spectra with low and high frequency peaks at 24 and 108kHz, respectively. The −10dB bandwidth was 35kHz. The average source level varied from 173to202dB re 1μPa (peak-to-peak) @ 1m. This is considerably lower than source levels described for Canadian killer whales foraging on salmon. It is suggested that biosonar clicks of Norwegian killer whales are adapted for localization of prey with high target strength and acute hearing abilities.

Abstract: The fatty acid composition (FAC) was determined in muscle samples from 963 herring (Clupea harengus L.) caught during 2001–2003 in waters around Denmark. The overall variation in FAC was mainly related to seasonal (summer or winter) and annual (2001, 2002 or 2003) variation. No clear variation due to place of catch (Baltic Sea, Skagerrak, Kattegat or the northern, western or eastern part of the North Sea) was found. Of the nutritionally important n-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), EPA seemed to show a seasonal variation, with the highest amount during summer, whereas no periodic variation was observed for DHA. Herring from one catch, however, were found to have an extraordinarily high amount of EPA (11%) compared with all other catches (amounts of EPA ranging from 4 to 8%). This high EPA content found only in herring caught in May 2003 in the northern North Sea (NSN) was in large contrast to the herring caught in the same place 3 months earlier, which had the lowest EPA content overall. The abrupt increase in EPA level from February to May was not correlated with biological parameters such as spawning type, maturity status, age, sex and size, but it might be related to variation in the FAC of the calanoid copepods on which the herring feed. Considering the nutritional aspects, the high-EPA herring from the NSN catch in May 2003 had a relatively low lipid content (7%), making them highly suitable for human consumption. Copyright © 2007 Society of Chemical Industry

Abstract: Nine prey species (n = 7431) were fed to four captive female Steller sea lions (Eumetopias jubatus (Schreber, 1776)) in 11 feeding trials over 75 days to investigate the effectiveness of different methods used to determine diet from prey hard remains. Trials aimed to replicate short (1–2 days) and long feeding bouts, and consisted of single species and mixed daily diets. Overall, 25.2% ± 22.2% (mean ± SD, range 0%–83%) otoliths were recovered, but recovery rates varied by species (ANOVA, P = 0.01) and were linearly related to otolith robustness (R2 = 0.88). Squid beaks were recovered at higher frequencies (mean 96%) than the otoliths of all species. Enumerating both non-otolith skeletal structures and otoliths (together termed bones) increased species recovery rates by twofold, on average (P < 0.001), with increases up to 2.5 times for Pacific herring (Clupea pallasii Valenciennes in Cuvier and Valenciennes, 1847) and 3–4 times for salmonids. Using bones reduced interspecific differences (P = 0.08), but r...

Abstract: Since 1980 the stock of Norwegian spring-spawning herring Clupea harengus has increased 10-fold to >5 × 10 6 t. This increase has probably played a vital role in repeated collapses in the capelin Mallotus villosus stock in the Barents Sea since the mid-1980s. After several decades of increase during a period of high capelin abundance in the Barents Sea, the population of black- legged kittiwakes Rissa tridactyla breeding in northern Norway started to decline in the early 1980s, reaching rates of -8% yr -1 since 1995. Earlier studies in the southwestern Barents Sea suggested that the black-legged kittiwakes in the region were dependent on capelin as prey for successful breeding. This study further documents a positive relationship between diet composition and fish abundance, and the negative effect that a switch to feeding on herring in the absence of capelin has had on chick provisioning and possibly fledging success.

Abstract: The multifrequency backscattering characteristics of echotraces of Atlantic herring (Clupea harengus) and Norway pout (Trisopterus esmarkii) are described. These fish cohabit similar areas of the N...

Abstract: Norwegian spring-spawning herring (Clupea harengus) spawn in February and March along the Norwegian coast from 588N to 698N. The larvae are transported north with the coastal current, and in autumn, the main part of the 0-group is found in the Barents Sea, and a smaller and variable fraction ends up in coastal and fjord nursery areas that experience a wide range of environmental conditions and fish densities. Based on data from herring 0–2 years old collected from 1970 to 2004, there is a positive relationship between temperature and the growth of this coastal component, in terms of length, weight, condition factor, and annual otolith increment width, and a negative relationship between acoustic abundance and the same growth indices. In general, juvenile growth decreased northwards along the coast concurrently with decreasing summer and autumn temperatures and increasing acoustic abundance. It seems, therefore, that there may be interference in the relationship between juvenile herring growth and temperature, attributable to variable recruitment, currents, larval drift, and advection into the fjords, causing latitudinal and interannual differences in fish density, and hence variable competition for food.

Abstract: The meso-scale trophic dynamics of cod Gadus morhua were examined based upon tri-monthly stomach sample collections from a nearshore, localized (c. 800 km2) region off Cape Cod, Massachusetts, U.S.A. The major objective for this work was to relate any changes in cod diet and amount of food eaten to seasonal variations in prey availability, water temperature and spawning at a spatial scale between broad-scale and laboratory studies. Results suggested that the type and amount of food eaten by cod was generally consistent throughout a year and repeatable across years. Cod feeding was marked by two periods of increased feeding, corresponding to the arrival of small pelagic fishes in the area. This pelagic migration and subsequent increased feeding by cod occurred during important periods in the life history of cod (e.g. spawning and overwintering). Similar annual patterns in food consumption and diet composition were remarkably consistent over the 2·5 years of the project, suggesting important feeding periods for cod that correspond to environmental and biological events. The diet of cod was composed primarily of several species of forage fishes [e.g. herrings (predominantly Atlantic herring Clupea harengus), sand lance Ammodytes sp. and Atlantic mackerel Scomber scombrus], ophiuroids, Cancer sp. crabs and other small crustaceans. It was inferred that cod exhibited a maintenance diet on local forage fishes and benthic macroinvertebrates, augmenting their diet by seasonally gorge feeding upon migrating pelagic species.

Abstract: Herring Clupea harengus L. viscera were examined for endoparasitic infections as part of a multidisciplinary stock identification project (WESTHER, EU Contract no. Q5RS-2002-01 056) which applied a range of stock discrimination techniques to the same individual fishes to obtain comparable results for multivariate analysis. Spawning and non-spawning adults, and juvenile herring were caught, over 3 years, by commercial and research vessels from numerous locations to the west of the UK and Ireland, along with control samples of spawning fish from the eastern Baltic Sea, and juveniles from sites in the eastern and western North Sea, and the north of Norway. The metacercariae of two renicolid digeneans (Cercaria pythionike and Cercaria doricha), one larval nematode (Anisakis simplex s.s.) and one larval cestode (Lacistorhynchus tenuis) were selected as tag species. Results were compared with those from herring collected between 1973 and 1982, which suggested remarkable stability in the parasite fauna of herring in the study area. These species were used to compare the parasite infracommunities of spawning herring. A significant variation in infracommunity structure was observed between different spawning grounds. These results suggest that the parasite fauna of herring are spatially variable but remain temporally stable in both the short and long term. Significant differences in prevalence and abundance of infections and comparisons of parasite infracommunity enabled the separation of putative herring stocks west of the British Isles. Distinctive patterns of parasite infection in two different spawning groups off the north coast of Scotland suggest that this area is occupied by two spawning populations, one recruiting from the west of Scotland, the other from outside this area, and most likely from the eastern North Sea. The distribution patterns of L. tenuis, C. doricha and C. pythionike suggest the potential for fish that spawn in three distinct International Council for the Exploration of the Seas (ICES) management units to be present in mixed aggregations found over the Malin Shelf, with significant implications for management in this area.

Abstract: Objective: To assess the effect of a 4-week herring diet compared to a reference diet on biomarkers for cardiovascular disease in obese subjects. Design: Randomized crossover trial. Setting: Department of Internal Medicine, Sahlgrenska University Hospital. Subjects: Fifteen healthy obese men and women ( age 24-70 years) included, 13 completed. Intervention: Subjects were randomly assigned to four weeks of herring diet ( 150 g baked herring fillets/day 5, days/week) or reference diet ( pork and chicken fillets) and switched diets after 2 weeks washout. P-total cholesterol, p-TAG, p-HDL, p-HDL(2), p-HDL(3), p-LDL, p-apolipoprotein A, p-apolipoprotein B, p-Lipoprotein ( a), p-fibrinogen, p-C- reactive protein and p-antioxidative capacity were analysed at 0,2,4,6,8 and 10 weeks. Results: P-HDL was significantly higher after the herring diet period compared to after the reference diet period; 1.22 vs 1.13 mmol/l ( P = 0.036). There was a small, but not statistically significant, decrease in TAG but no effect on other biomarkers. TEAC and FRAP, but not ORAC-values, indicated that plasma antioxidants may have been reduced. CRP tended to be lower after the herring diet compared to after the reference diet. Conclusions: Consumption of oven-baked herring ( 150g/day, 5 days/week) for 4 weeks, compared to consumption of pork and chicken fillets, significantly increased p-HDL. Patients with insulin resistance and obesity, who commonly have low HDL, may therefore benefit from addition of herring to the diet.

Abstract: The Baltic Sea ecosystem and fish stocks contain high concentrations of environmental chemicals such as polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs), and polychlorinated biphenyls (PCBs). This study forecasts how changes in fishing or natural mortality would probably influence concentrations of PCDD/F and PCB in the Bothnian Sea (Northern Baltic) herring (Clupea harengus L.). An age-structured simulation model was developed to forecast herring stock dynamics, catches, and weight-at-age under different assumptions about exploitation and natural mortality. The simulated herring weight-at-age estimates were employed in a bioenergetics model capable of simultaneous estimation of bioaccumulation of 17 PCDD/F and 37 PCB congeners. Although the natural variability in recruitment greatly influences the stock dynamics, considerable changes in weight-at-age would ensue changes in exploitation rate or in natural mortality rate. If exploitation rates increase, growth rates would be hi...

Abstract: In the southeastern Bering Sea, Pacific herring (Clupea pallasii) migrate from the Pribilof Islands region where they overwinter, to the Alaska coast where they spawn in spring. The migration sustains a nearshore commercial fishery that targets roe-bearing females just prior to spawning. Herring also are taken as bycatch in groundfish trawl fisheries, where time and area closures in these fisheries are triggered by herring bycatch caps. Using herring bycatch data collected since the 1970s by National Marine Fisheries Service (NMFS) observers aboard groundfish fishing vessels, a retrospective analysis was conducted to describe the seasonal migration pattern of Pacific herring in the southeastern Bering Sea and to study its spatial and temporal variability. Observed changes in herring catch per unit of effort were compared with variability in climate and oceanographic conditions. The seasonal migration is complex, but annual shifts in migration routes and a possible northward shift of the overwintering grounds was identified. Pre-spawning herring aggregated in different areas depending on whether spawning occurred early or late in spring. The thermal structure of the ocean around the ice edge appears to influence herring migration timing and route as well as spawning date. Thus, on the basis of recent changes in sea-ice extent and duration, we suggest that the herring bycatch savings area that was developed from data collected in the 1980s should be revised to reflect prevailing conditions. r 2007 Elsevier Ltd. All rights reserved.

Abstract: Summary A microwave fat: water content meter designed for use on pelagic fish has been found to exhibit seasonal changes in calibration. This has been examined in detail for sprats (Sprattus sprattus) and herring (Clupea harengus) and is ascribed in part to the seasonal changes in these species of the protein content, which influences the rotational mobility of water in the tissue. Various solutions to the problems are proposed.

Abstract: Two methods for estimating digestion rate were evaluated and the digestion rate to disappearance was estimated to be 0·30 h−1 for herring Clupea harengus feeding on capelin Mallotus villosus larvae. Due to high individual variability in feeding rates in schooling fish species, groups should be fed in separate tanks and stomach contents collected from each group at a predetermined time.

Abstract: During the Late Stone Age, the sites of Ajvide and Jettbole were located on the seashore but in quite different marine environments. Ajvide on Gotland had direct access to the open sea of the centr ...

Abstract: A new innovative topless shrimp trawl was designed and tested in the flume tank, and at sea to evaluate its potential of reducing finfish bycatch in the pink shrimp fishery in the Gulf of Maine The trawl design removed the square and the top part of the section after the square (first belly section), to become “topless” A five-day sea trial was carried out using the alternating tow method to compare the topless trawl and a commercial (control) trawl The target species was the pink shrimp (Pandalus borealis) and the major bycatch species was Atlantic herring (Clupea harengus) that formed 906% of all bycatch by weight Comparative fishing indicated that the topless trawl reduced bycatch of Atlantic herring by an average of 866%, and at the same time produced a modest increase of 135% in the catch of the pink shrimp There was some increase in the bycatch of flounders, particularly American plaice and winter flounder, though overall amount of flounder bycatch was less than 3% of the total catch The reduction of Atlantic herring was most likely due to the fish escaping over the headline where the top panel was removed The increased bycatch of flounders (and increased catch of shrimp) might have resulted from a wider wingend spread and subtle differences in the footgear between the topless and commercial trawls The substantial reduction of Atlantic herring, the major bycatch species, without a reduction of the target shrimp species proved the concept of the topless trawl and may have a profound impact on other shrimp trawl fisheries around the world

Abstract: We surveyed little-known ray-finned fish assemblages from Maryland's coastal bays in order to establish species-habitat relationships for common species. From 1996–1999, 25 sites were sampled monthly with otter trawls in the coastal bays of Maryland. Anchoa mitchilli (bay anchovy) constituted nearly 50% of the catch for each year, and species composition was largely similar across years, with some differences likely related to variation in recruitment. For example, Clupea harengus (Atlantic herring) was particularly abundant during 1996 and 1999 following their spawning season. We used canonical correspondence analysis to determine how assemblages were related to temperature, dissolved oxygen (DO), salinity, and land-use variables during summer (June–September) and throughout the rest of the year. A gradient correlated with temperature and DO significantly structured assemblages throughout most of the year; during summer, the proportion of wetland habitat was important. We demonstrate that enviro...