Directorate of Fisheries

The utilisation of dietary carbohydrates and their effects on fish metabolism are reviewed. Details on how dietary carbohydrates affect growth, feed utilisation and deposition of nutrients are discussed. Variations in plasma glucose concentrations emphasizing results from glucose tolerance tests, and the impact of adaptation diets are interpreted in the context of secondary carbohydrate metabolism. Our focus then shifts to selected aspects of hormonal regulation of carbohydrate metabolism and dietary carbohydrates and their variable effects on glycogen and glucose turnover. We analyse the interaction of carbohydrates with other nutrients, especially protein and protein sparing, and de novo synthesis of lipids, and finish by discussing the correlation of dietary carbohydrates with fish health.

The possible roles of viruses in phytoplankton dynamics were investigated in seawater mesocosms with natural assemblages of phytoplankton growing under various nutrient regimes. Blooms of the marine coccolithophorid Emiliania huxleyi (Lohmann) Hay & Mohler were in some cases succeeded by an increase in the abundance of a morphologically homogeneous population of viruses. The viruses had an hexagonal outline and were about 180 nm in diameter. Similar viruses were found both intracellularly and associated with apparently lysed cells. Viral lysis could account for 25 to 100 % of the net mortality of E huxleyi when the blooms declined under non-limiting nutrient conditions or when the nitrate concentration was low. Production of viruses was limited when the phosphate concentration was low. Dur~ng a bloom of E. huxleyi in Norwegian coastal waters in 1990 we found that the concentration of free algal viruses was increasing at the end of the bloom, indicating that viruses of E. huxleyi may be important under natural conditions as well. These results suggest that viral mortality of phytoplankton may be an important factor regulating community structure, diversity and biomass production in marine environments.

Summary 1. Functional traits have been extensively used to describe, group and rank species according to their functions. There is now growing evidence that intraspecific functional variability, as well as interspecific variability, can have significant effects on community dynamics and ecosystem functioning. A core hypothesis for the use of functional traits expressed as species means, that their intraspecific variability is negligible compared with their interspecific variability, has however been too rarely tested empirically. We then addressed four questions: Is intraspecific functional variability across species ranges negligible compared with interspecific variability? Are the major resource economics trade‐off and functional strategies robust to individual trait variability? Are species rankings or ordination robust across species ranges once considering intraspecific variability? Can species be discriminated by their leaf traits? 2. Using an environmentally stratified sampling design within an alpine catchment, we collected five functional traits for 13 common plant species with contrasting life histories and traits. Several populations from a range of environmental conditions were then sampled for each species across their ranges. 3. With an original combination of single‐trait and multi‐trait analyses, we highlighted a non‐negligible contribution of intraspecific variability to overall functional trait variability (∼30%). Although not affecting general and well‐known functional trade‐offs and strategies, intraspecific functional variability had the potential to alter species ordination and produced a functional continuum rather than a clear‐cut species classification. 4. Deciding whether intraspecific functional variability can be considered as negligible – species being represented by mean trait values –, or not – species being represented by multivariate trait distributions –, is an essential question for multiple ecological issues. However, this decision cannot be generic, but will depend on the studied system and selected traits and species, as well as on study objectives.

MOTIVATION: The BioTIME database contains raw data on species identities and abundances in ecological assemblages through time. These data enable users to calculate temporal trends in biodiversity within and amongst assemblages using a broad range of metrics. BioTIME is being developed as a community-led open-source database of biodiversity time series. Our goal is to accelerate and facilitate quantitative analysis of temporal patterns of biodiversity in the Anthropocene. MAIN TYPES OF VARIABLES INCLUDED: The database contains 8,777,413 species abundance records, from assemblages consistently sampled for a minimum of 2 years, which need not necessarily be consecutive. In addition, the database contains metadata relating to sampling methodology and contextual information about each record. SPATIAL LOCATION AND GRAIN: ). TIME PERIOD AND GRAIN: BioTIME records span from 1874 to 2016. The minimal temporal grain across all datasets in BioTIME is a year. MAJOR TAXA AND LEVEL OF MEASUREMENT: BioTIME includes data from 44,440 species across the plant and animal kingdoms, ranging from plants, plankton and terrestrial invertebrates to small and large vertebrates. SOFTWARE FORMAT: .csv and .SQL.

Fishers have been complaining about the effects of bottom trawl gear on the marine environment since at least the 14th century. Trawl gear affects the environment in both direct and indirect ways. Direct effects include scraping and ploughing of the substrate, sediment resuspension, destruction of benthos, and dumping of processing waste. Indirect effects include post‐fishing mortality and long‐term trawl‐induced changes to the benthos. There are few conclusive studies linking trawling to observed environmental changes since it is difficult to isolate the cause. However, permanent faunal changes brought about by trawling have been recorded. Research has established that the degree of environmental perturbation from bottom trawling activities is related to the weight of the gear on the seabed, the towing speed, the nature of the bottom sediments, and the strength of the tides and currents. The greater the frequency of gear impact on an area, the greater the likelihood of permanent change. In deeper water where the fauna is less adapted to changes in sediment regimes and disturbance from storm events, the effects of gear take longer to disappear. Studies indicate that in deep water (>1000 m), the recovery time is probably measured in decades.

Residents’ overall well-being and quality-of-life require a deeper understanding of their perceived social impacts of tourism to determine appropriate management strategies to promote behaviours in support of tourism development. Aligning with the 2030 Agenda for sustainable development, this paper proposes a new framework for residents’ quality-of-life. Bringing together multi-disciplinary evidence from environmental, social and cognitive psychology, political science and tourism, this study critically examines how residents’ perceived social impacts of tourism and their interpersonal trust can make them become more place attached and protect their tourism resources. The framework proposes that residents’ perceived social impacts of tourism exerts a direct influence on residents’ interpersonal trust. It further posits that residents’ perceived social impacts of tourism and their interpersonal trust exert a direct influence on residents’ place attachment. The proposed model further considers place attachment to exert a direct influence on residents’ pro-social and pro-environmental behavioural intentions. Pro-social behaviour is proposed to influence pro-environmental behaviour. Further pro-social and pro-environmental behaviours are proposed to influence residents’ support for tourism development. The framework then considers residents’ support for tourism development to exert a direct influence on residents’ overall quality-of-life. The theoretical contributions, practical implications for sustainable community tourism and sustainable tourism in general and the limitations of the study are discussed.

Triplicate groups of Atlantic salmon (Salmo salar L.) were fed four diets containing different oils as the sole lipid source, i.e., capelin oil, oleic acid-enriched sunflower oil, a 1:1 (w/w) mixture of capelin oil and oleic acid-enriched sunflower oil, and palm oil (PO). The beta-oxidation capacity, protein utilization, digestibility of dietary fatty acids and fatty acid composition of lipoproteins, plasma, liver, belly flap, red and white muscle were measured. Further, the lipid class and protein levels in the lipoproteins were analyzed. The different dietary fatty acid compositions did not significantly affect protein utilization or beta-oxidation capacity in red muscle. The levels of total cholesterol, triacylglycerols, and protein in very low density lipoprotein (VLDL), low density lipoprotein (LDL), high density lipoprotein (HDL), and plasma were not significantly affected by the dietary fatty acids. VLDL, LDL, and HDL fatty acid compositions were decreasingly affected by dietary fatty acid composition. Dietary fatty acid composition significantly affected both the relative fatty acid composition and the amount of fatty acids (mg fatty acid per g tissue, wet weight) in belly flap, liver, red and white muscle. Apparent digestibility of the fatty acids, measured by adding yttrium oxide as inert marker, was significantly lower in fish fed the PO diet compared to the other three diets.

The spawning periods of four temperate or high-latitude fish species - Pacific sockeye salmon, herring, plaice and cod - have been examined. The mean date of peak spawning was established and it was found that the standard deviation of this mean date was low, often less than a week. For three species no trend of date of peak spawning was found; a trend towards later spawning was detected in the Arcto-Norwegian cod stock, about eight ays in seventy years. In contrast the Californian sardine was shown to spawn at very variable periods and it is likely that tuna in the North Pacific anticyclone spawned during most of the year. It is likely that production is continuous in the anticyclonic regions and discontinuous in the high-latitude cyclones; this would be sufficient to account for the differences found between the two groups of fish.

Summary 1. Winged morph production in aphids is a phenotypic trait that has traditionally been seen as a response to unfavourable environmental conditions. The evidence to support this theory is reviewed and the ecological and evolutionary significance of the findings is discussed. 2. The common assertion of poor host‐plant nutritional quality leading to increased production of winged morphs does not always apply, particularly when the host‐plant quality is exceptionally poor. The available data are skewed heavily towards Myzus persicae , and for this species the dynamical change in plant quality appears to be important with respect to wing induction. 3. Crowding may be a less influential stimulus for wing induction as study methods approach natural conditions experienced by aphids on their host plant. 4. The growing evidence that interactions with other organisms can induce the production of winged morphs by aphid colonies is reviewed. In the case of natural enemies, such a response by an aphid colony may be regarded as induced defence. Wing induction may also act as a means of transmission for a virus or fungal pathogen.

Aspects of the reproduction of reared cod, Gadus morhua L., with special emphasis on the females, were studied under laboratory conditions. The fecundity and condition factor were 2–5 and 1–5 times, respectively, that of wild cod. A total of 18 spawning females were kept in separate tanks/ chambers, each with one or two males. Seven of the 18 females were classified as stressed, based upon behaviour, irregular spawning intervals and low fertilization rates of the eggs. The reared cod were found to spawn 17–19 batches. The number of eggs liberated in each batch normally followed a smooth, dome‐shaped curve with time. The fertilization rate was normally 100%. Egg size decreased from first to last batch and the egg dry weight decreased by about 20–30%. The reared cod showed the same egg diameter to dry weight relation as wild cod. Egg diameter of first batch and maternal fish length were significantly positively correlated. The mean spawning interval for the female and the mean water temperature during its spawning were negatively correlated. The reared cod spawned in both the night and the day for about 50–60 days.

Blood samples from healthy adult Atlantic salmon fed an optimal diet in net sea pens were collected at intervals from October to May. Haematological determinations and biochemical serum analyses were carried out on 20 fish in each of seven samples. The ranges of haemato‐logical values for sample means were: haematocrit 44–49%, haemoglobin 8.9–10.4 g 100ml −1 , red blood cell count 0.85–1.10 × 10 12 l −1 , MCV 441–553 × 10 −15 1, MCH 94–106 × 10 −6 g, MCHC 19.4–21.7 g 100ml −1 and leucocrit 0.43–0.96%. The ranges of enzyme activities in serum, for sample means, were: alkaline phosphatase 647–988Ul −1 , aspartate aminotrans‐ferase 202–351 Ul −1 and alanine aminotransferase 4–8 Ul −1 . The ranges of the other parameters analyzed in serum were: total protein 41.6–56.6 gl −1 , albumin 18.3–24.3 gl −1 , albumin/total protein ratio 39.3–44.0%, creatinine 26–46 μmol, triglycerides 2.53–4.98 μmol and cholesterol 9.3–12.8 μmol. These values are considered to be the normal ranges in healthy fish. Variations due to seasonal changes, and the clinical significance of the selected parameters, are discussed. Data showing the reproducibility of the biochemical analyses in serum are presented.

The aim of the present study was to investigate the effects of different dietary sustained-release microencapsulated sodium butyrate (MSB) products (0 (non-supplement), 1·5 and 3·0 h) for a control or oxidised soyabean oil (SBO) diet on fish production, intestinal mucosal condition, immunity and intestinal bacteria in juvenile common carp (Cyprinus carpio). Dietary MSB increased weight gain and reduced the feed conversion ratio within the control and oxidised SBO groups. Gut mucosa was damaged in the oxidised SBO group fed without MSB, in contrast to a normal appearance found in fish fed the MSB1·5 and MSB3·0 diets in the oxidised SBO group. Microvillus density increased in fish fed the MSB1·5 and MSB3·0 diets in the oxidised SBO group (P< 0·001); however, microvillus density was affected by the different pre-fed diets in the midgut (P< 0·001) and by the different sustained-release times of MSB in the distal gut (DG) (P= 0·003). The interaction between the pre-fed diets and the sustained-release times of dietary MSB was significant for the relative gene expression levels of gut heat shock protein-70 (HSP70), pro-inflammatory cytokines (IL-1β and TNF-α) and anti-inflammatory cytokines (transforming growth factor-β) within each gut segment, except for HSP70 in the DG and IL-1β in the foregut. Modulation of adherent bacterial communities within each gut segment investigated was not obvious when the common carp were fed the diets with MSB, as similarity coefficients of >0·79 were observed. These results indicated that MSB can be used as a dietary supplement to repair or prevent intestinal damage in carp fed oxidised SBO.

The author discusses the way in which bacterial and fungal diseases of crustaceans can be and have been transmitted via commercial movements of stocks. Two classic examples of such diseases are presented, namely gaffkaemia (a bacterial disease of marine lobsters) and crayfish plague (a fungal disease of freshwater crayfish). In both cases, there is ample evidence that much of the disease spread can be linked to the commercial movement of infected animals caught from infected wild stocks and transported over large distances for wholesale and retail. In the case of crayfish plague, much of the relentless spread of this disease through Europe for nearly 140 years can also be liked to the movement of contaminated fishing equipment without disinfection.

Abstract This study addressed the issue of the dietary supplements; probiotic, prebiotic and synbiotics considered as functional food ingredients in sturgeon aquaculture. Developments of this strategy have been suggested and practiced as an alternative to antibiotic administration in aquaculture. Sturgeons are commercially valuable species due to their meet and roe, which is made into caviar. Aquaculture of sturgeons up to marketable size has increased during the last decade while disquieting decreases have been noticed of the natural populations. In line with the expand evaluations of microbial dietary supplements and prebiotics in finfish and shellfish aquaculture, the scientific community has also increased their interest in approaches to these issues in sturgeon aquaculture. The present review summarizes and discusses the results on intestinal microbiota of sturgeon species and the effects of probiotic, prebiotic or synbiotic administration on growth performance, gut physiology, intestinal microbiota, immune response and health. Furthermore, this study tries to cover the gaps of existing knowledge and suggest issues that merits further investigations.

The behavioural and physiological effects of surgical implantation of dummy miniature acoustic transmitters into the peritonealcavities ofjuvenile Atlantic salmon, Salmo salar L., were assessed. lntraperitoneal implantations had no significant effect on growth, feeding or swimming behaviour in either parr or smolts. Recovery from the surgical implantation was both rapid and total; infection was absent; and physiological processes such as smoltification and maturation of testes in precocious parr were unaffected. Expulsion of the transmitter through the body wall, not through the implantation wound, occurred in a number of fish but without adversely affecting the animals. The intraperitoneal implantation technique is discussed in relation to its use during biotelemetry studies.

Fitness costs of reproduction play a key role in understanding the evolution of reproductive tactics. Nevertheless, the detection and the intensity of costs of reproduction vary according to which life-history traits and species are studied. We propose an evolutionary model demonstrating that the chance of detecting a cost of reproduction should be lower when the fitness component studied has a low rather than high variance. Consequently, the fitness component that is affected the most by costs of reproduction should vary with life speed. Since long-lived species have developed a strategy that avoids jeopardizing their survival and short-lived species favour current reproduction, variance in survival is smaller and variance in reproduction higher in long-lived vs. short-lived species. We review empirical studies of costs of reproduction in free-ranging mammals, comparing evidence of costs reported among species and focal traits. In support of our model, more studies reported evidence of reproductive costs of reproduction in ungulates than in rodents, whereas survival costs of reproduction were more frequent in rodents than in ungulates. The life-history model we propose is expected to apply to any species, and hence provides a better understanding of life-history variation, which should be relevant to all evolutionary ecologists.

Rapid loss of sea ice is opening up the Arctic Ocean to shipping, a practice that is forecasted to increase rapidly by 2050 when many models predict that the Arctic Ocean will largely be free of ice toward the end of summer. These forecasts carry considerable uncertainty because Arctic shipping was previously considered too sparse to allow for adequate validation. Here, we provide quantitative evidence that the extent of Arctic shipping in the period 2011-2014 is already significant and that it is concentrated (i) in the Norwegian and Barents Seas, and (ii) predominantly accessed via the Northeast and Northwest Passages. Thick ice along the forecasted direct trans-Arctic route was still present in 2014, preventing transit. Although Arctic shipping remains constrained by the extent of ice coverage, during every September, this coverage is at a minimum, allowing the highest levels of shipping activity. Access to Arctic resources, particularly fisheries, is the most important driver of Arctic shipping thus far.

This paper discusses the nutrient composition and the nutritional importance of green leaves and wild gathered foods in an area with surplus food production in Mali. In this West African country, there is little information about the nutrient composition and the nutritional quality of foods in general, and of wild gathered foods in particular. Food frequency was collected in two cross-sectional surveys. Focus group discussions with women in the area were used to collect information about seasonality, availability and preparation of various foods. Selected food samples were collected for chemical analysis of nutrient composition. The food samples of green leaves (Adansonia digitata, Amaranthus viridis, Tamarindus indica, Allium cepa), seeds and flour (Parkia biglobosa) and fruits (Tamarindus indica) were analysed for water, energy, fat, protein, minerals, amino acids and carotenoids. Availability and use of the foods varied with seasons. In the rainy season, wild gathered foods (e.g. A. digitata) were used as much as fresh cultivated foods (e.g., A. viridis and A. cepa). The wild food resources were more frequently used in rural than in urban areas, with A. digitata as the dominating green leaves. Green leaves were rich in energy, protein and minerals (calcium, iron). Leaves of A. viridis were, in particular, rich in beta-carotene (3290 micrograms/100 g). Chemical score in dried green leaves varied from 47 (A. cepa) to 81 (A. digitata), with lysine as the first limiting amino acid. P. biglobosa fermented seeds, with 35% fat and 37% protein were a complementary source of lysine in the diet. Based on the seasonality, the frequency of use and the nutrient contents of selected green leaves and wild gathered foods in Koutiala district, it is concluded that these traditional and locally produced foods are valuable and important nutrient contributors in the diet both in rural and urban areas, but most important in rural areas.

Di-(2-ethylhexyl)phthalate (DEHP) and total phthalate ester plasticizer levels were determined in milk, cream, butter and cheese samples from a variety of sources from three European countries (UK, Norway and Spain). Samples of milk (from Norway) obtained at various stages during collection, transportation and packaging operations showed no apparent trends in phthalate contamination with total phthalate levels (expressed as DEHP equivalents) in the raw milk of between 0.12 and 0.28 mg/kg. On processing the DEHP was concentrated in the cream at levels up to 1.93 mg/kg, whereas low fat milk contained from < 0.01 to 0.07 mg/kg. Retail dairy products (from Spain) were contaminated with < 0.01-0.55 mg/kg DEHP with a maximum total phthalate level of 3.0 mg/kg in cream samples. UK pooled milk samples from doorstep delivery (obtained from different regions of the country) contained low levels of DEHP (< 0.01-0.09 mg/kg) and total phthalate (0.06-0.32 mg/kg). Retail UK samples of cheese, butter and other fatty products varied considerably in their levels of contamination, the highest being cheese samples containing 17 mg/kg of DEHP and 114 mg/kg total phthalate. However, the majority of samples contained 0.6-3.0 mg/kg DEHP and 4-20 mg/kg total phthalate. UK cream samples contained levels of 0.2-2.7 mg/kg DEHP and 1.8-19.0 mg/kg total phthalate. The level found in these products was too high to have resulted solely from milk by concentration in the fat phase and must therefore have arisen in other ways.

Five groups of Altantic salmon, Salmo salar L., (80 g postsmolt) were fed moist diets containing increasing levels of starch from 0% to 31% and concomitant decreasing levels of protein. The results showed that feeding a diet containing 22% lipid with no starch or a starch inclusion higher than 22% exerts negative effects on growth and feed utilization. A starch inclusion above 9% resulted in decreased starch digestibility, while protein digestibility was not influenced by the dietary starch content. Undigested starch is suggested to affect lipid digestibility in the same manner as dietary fibre. The reduced digestibility by high levels of dietary starch led to increased loss of particulate matter to the environment. Taking into account feed utilization and environmental aspects, the present experiment suggests that a diet containing approximately 9% starch is optimal.