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A phenomenon of undulating fluctuations of nekton abundance in the Kuroshio system is discussed on example of japanese sardineSardinops melanostictus, as the most abundant and the most fluctuating species. The so-called «sardine epochs» are distinguished according to this species abundance. The last such epoch ended in the early 1990s. Since 2014, structural changes occurred again in the nekton communities of the Pacific waters off Kuril Islands, caused by expansion of southern fish and squid species, primarily japanese sardine and chub mackerelScomber japonicus, and decreasing in abundance of japanese anchovyEngraulis japonicusand sauryCololabis saira. The scope of these changes allowed Russian fishermen to resume the fishery on japanese sardine and chub mackerel in the Russian exclusive economic zone since 2016. Annual catch of Japanese sardine increased steadily from 6,700 t in 2016 to 315,500 t in 2020. Over these 5 years, Russian fishermen landed 531,700 t of sardine and 167,900 t of chub mackerel. However, many Russian fishery forecasters believe that these reconstructions is only a «rehearsal» of the upcoming «sardine epoch», being based on formal climatic indices, without delving into the mechanisms of abundance fluctuations. The authors note that new «sardine epochs» cannot be predicted as completely similar to the previous ones. Several hypotheses on causes of the beginning and end of japanese sardine blooms are considered critically, and the conclusion is made that mechanisms which determine its year-classes strength are still unclear, as well as the reasons of undulating fluctuations of this species and some other nekton species abundance, because of high complexity of this problem.

AVISO satellite data on the speeds of geostrophic currents from 2004 to 2018 are used to associate a substantial reduction in the saury catch in recent years with a change in the oceanographic situation in the Russian fishing grounds off the coast of the southern and middle Kuril Islands and Hokkaido Island. Lagrangian maps of the origin of water masses, calculated for this period of time on the basis of the AVISO field, and with overlaid positions of fishing vessels of Russia, Japan and Korea, show that this catastrophic reduction is due to a change in the pathways of the nutrient-rich subarctic waters of the Oyashio current in recent years. The greatest changes in the hydrological regime since 2015 were caused by intensification of the third branch of the Oyashio, which transports the waters of this current to the open ocean. At the same time, traditional fishing grounds off the eastern coasts of Hokkaido and southern Kurils have been reduced, while good fishing grounds have appeared in the open ocean.

Formation of the surface structure mechanism of the South Kuril waters in the last two years has undergone significant changes. Therefore, the “cold” type of hydrological conditions prevailed in the South Kuril area during August-November 2017. The surface water temperature was below the norm by 1–2 °C. On the contrary, the “warm” type of hydrological conditions prevailed in the South Kuril area during August-November 2018 and the water temperature in the area under consideration was 1–3 °C higher than the average for many years. Saury fishing in 2018, as in 2017, began in the second decade of August on the peripheral fronts of the Ask eddy and continued here until the second decade of September. At the end of September, the fishing area formed in the southwestern part of the EEZ of the Russian Federation and, unlike last year, it remained until the beginning of the third decade of October. The “warm” type of hydrological conditions causes this duration of the fishery. Saury moved outside the EEZ in late October. Fishing for sardines and mackerel began in mid-July 2018 and was carried out on the northern periphery of the eddy A’. However, at the end of October, unlike in 2017, fishing here practically stopped due to a decrease in the temperature drops at the peripheral fronts of the eddy caused by the high temperature of the surface waters of the Oyasio current. In late October — the first half of November in 2018, mackerel and sardine fished in high-gradient areas of the Northern Subarctic Front (NSAF) close to the eastern and southern borders of the Russian EEZ. During fishing season 2018, in contrast to the previous year, schools of sardines and mackerel remained much longer in the economic zone of Russia.

8 pages, 4 figures, 2 tables.-- This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, This study documented the parasite faunas of the spiral valves of blue sharks Prionace glauca (L. 1758) and common thresher sharks Alopias vulpinus (Bonnaterre, 1788) caught in the California Current Large Marine Ecosystem (CCLME) north of the Mexican border. The spiral valves of 18 blue and 19 thresher sharks caught in the CCLME from 2009 to 2013 were examined for parasites. Seven parasite taxa were found in blue sharks and nine in threshers. The tetraphyllidean cestode Anthobothrium sp. (78% prevalence) was the most common parasite in blue sharks, and the phyllobothriid cestode Paraorygmatobothrium sp. (90% prevalence) was the most common in threshers. An adult nematode of the genus Piscicapillaria was found in threshers for the first time and may be a new species. Adult individuals of Hysterothylacium sp. were found in both shark species. The adult acanthocephalan Rhadinorhynchus cololabis and remains of the parasitic copepod Pennella sp. – both parasites of Pacific saury, Cololabis saira – were found in the intestines of threshers, indicating recent feeding on saury. This study paves the way for a more comprehensive examination, including more samples and a wider variety of shark species, to provide a greater understanding of shark feeding behaviour and possibly provide information on shark population biology, National Oceanographic Atmospheric Administration (NOAA)

Pacific saury Cololabis saira is widely distributed in the North Pacific, with commercial harvesting in the area between 140–172о E. Relationship of its commercial catches distribution with environmental factors is investigated using the daily SST data, the daily data set of multivariate ocean variational estimation system (MOVE) produced by Meteorological Research Institute (Japan) for the area between 140–159о E (about 95 % of all catches and 100 % of the Russian catches of saury were landed in this area in 1994–2017), and the daily set of saury catches position with 1 km resolution collected by the Russian vessel monitoring system. Spatial resolution for all data sets is upscaled to the resolution of MOVE system (0.1 x 0.1 degree). Contribution and permutation importance for the catch distribution are estimated for 184 possible combinations of SST and MOVE products with the lags of 0–7 days and moving average window from 0 to 7 days using the method of maximum entropy (MaxEnt). For synchronic relationships, the best results are found for SST, water temperature at 50 m depth and its spatial gradient, moreover, SST provides high contribution with the lag up to 2 days and the temperature at 50 m and its gradient — with the lag 3–7 days. The same sets of environmental parameters are used for the catches distribution modeling with GAMs and Random Forest techniques; the latter method shows better accuracy and other indices of the confusion matrix. Year-to-year changes of the total area with predicted conditions favorable for the saury fishery within the EEZ of Russia and Japan correlate strongly (r = 0.96, p < 0.05) with the total annual catch of saury, in particular for the extreme years (high catches in 2008, 2014, and 2018, low catch in 2017).

Eicosapentaenoic acid- and docosahexaenoic acid-enriched phospholipids (PLEPA/DHA) have versatile health-beneficial functions and can be well absorbed in the intestine. Herein, a precursor ion scan-driven hydrophilic interaction chromatography mass spectrometry (PreIS-HILIC-MS) method with the fatty acyl moieties of m/z 301.6 and 327.6 locked was established to specifically and selectively screen PLEPA/DHA in different fish oil samples, including saury, grass carp, hairtail, and yellow croaker. Taking saury oil as an example, a total of 24 PLEPA/DHA were successfully identified and quantified, including 20 PCEPA/DHA and 4 PEEPA/DHA. Finally, this method was validated in terms of sensitivity (limit of detection ≤ 4.15 μg·mL-1), linearity (≥0.9979), precision (RSDintraday ≤ 4.65%), and recovery (≥78.6%). The performance of the PreIS-HILIC-MS method was also compared with that of the traditional full-scan mode, and the former demonstrated its unique superiority in targeted screening of PLEPA/DHA in fish oils.

Pacific saury is an important high-seas fishery resource in the Northwest Pacific Ocean for the Chinese Mainland. Reliable and accurate catch per unit effort (CPUE) plays a significant rule in Pacific saury stock assessment. Many statistical models have been used in the previous CPUE standardization research. Here, we compare the performance of Generalized Linear Models (GLMs) and Generalized Additive Models (GAMs) using CPUE data collected from Chinese saury fishery in the Northwest Pacific Ocean from 2003 to 2017 (excluding data from Chinese Taipei), and evaluate the influence of spatial, temporal, environmental variables and vessel length on CPUE. Optimal GLM/GAM models were selected using the Bayesian information criterion (BIC). Explained deviance and 5-fold bootstrap cross-validation results were used to compare the performance of the two model types. Fitted GLMs accounted for 21.57% of the total model-explained deviance, while GAMs accounted for 38.95%. Predictive performance metrics and 5-fold cross-validation results showed that the best GAM performed better than the best GLM. Therefore, we recommend GAM as the preferred model for standardizing CPUE of Pacific saury in the Northwest Pacific Ocean.

We characterized vacuum-packed whole saury (Cololabis saira) treated using radio-frequency (RF) heating and compared it with that treated using conventional retort heating. RF heating is electrical heating based on dielectric heating. In this study, the effect of RF heating on softening and collagen in backbone was analyzed. RF heating heated the center of fish faster than water. The backbone was softened to a chewable level, and the heating time was shortened to one-third. The amount of crude protein and collagen in backbone decreased with decreasing elasticity, although that heated using RF (131°C) still contained a higher amount than conventional heating. However, β and γ collagen, and then α1 and α2 collagen chain in backbone disappeared with heating; therefore, collagen was degraded to collagen peptide. Results confirmed that RF heating provided wholly eatable fish containing low-molecular collagen peptide in a short heating time.

This paper employed ray tracing to design a spotlighting optical lens. TracePro was used to design and simulate a light-emitting diode (LED) lamp for saury fishing with an optimized light distribution that focused light into a fishing net beside a fishing vessel. In the simulation analysis, the irradiance of incandescent lamps deployed on saury fishing vessels was taken as the base figure. The average irradiance of LEDs without the designed lens was 0.83 times the incandescent lamps, whereas the average irradiance of the LEDs with the designed lens was 1.6 times the incandescent lamps. However, considering the usage habits of saury fishing boats, the experimental testing installed the combination on two saury fishing boats. The average irradiance of a combination of LEDs with the designed lens and incandescent lamps ship was 1.14 times the incandescent lamps ship. The boats sailed into the northwest pacific to conduct fuel consumption and catch experiments over three voyages. Savings of 13.0% were achieved in fuel cost required per ton of catch volume, and savings of 20.2% were achieved in average fuel consumption. No significant difference in terms of catch volume was revealed between combination lamp poles and incandescent lamp poles. The proposed lens design effectively enhanced the functionality of LED fishing lights on saury fishing boats. Substituting a portion of incandescent lamps with LED lamps using the proposed lens could effectively save fuel without significantly affecting catch volumes.

A database with Pacific saury catch locations in 2004–2019 fishing seasons in the region of the Kuril and Hokkaido islands was created to study a connection of favorable fishing grounds with mesoscale fronts in the area. The locations of the fronts have been identified with the help of daily altimetry-based Lagrangian maps computed for a large number of artificial particles. Based on the Lagrangian analysis of the multi-year simulation results, we distinguished persistent Lagrangian fronts with accumulation of catches, which were associated with the Soya Warm Current, the 1st, 2nd and 3rd Oyashio branches and with quasi-stationary Hokkaido and Bussol anticyclones. The simulated Lagrangian fronts, which are accessible practically in the real time, have been shown to be useful proxies for locations of hydrological fronts with potential fishing grounds. The proximity of catch sites to locations of strong Lagrangian fronts has been shown statistically using the maximal gradients of the Lyapunov field as an indicator of fronts. The origin maps have been used for analysis of interannual variation in the spatial distribution of the nutrient-rich Oyashio and Okhotsk Sea water masses. Calculating surface Oyashio transport in the altimetry era, we connected the catastrophic decrease in saury catches in traditional fishing places in 2015–2019 with a change in the pathways of the Oyashio water. The significant increase of the Oyashio transport in the recent years was supposed to be favorable for formation of potential fishing grounds far east off Kurils and Hokkaido coasts. This factor together with a smaller stock-size saury immigration was supposed to explain a decrease in the actual catches after 2014 and a displacement of the fishing grounds to the open ocean.

General patterns of the pacific saury feeding migrations in the North-West Pacific are determined on results of fishing operations conducted by a group of Russian fishery vessels in June-November, 2014. The main route of migration in June-July was directed westward and northwestward, to the open ocean. In the late summer and early autumn the saury migrated southwestward along the Oyashio Front. Towards the end of the feeding period, the main portion of large-sized saury moved along the 1 st branch of Oyashio to the EEZ of Japan and its other portion moved along the 2 nd branch of Oyashio to the open ocean waters. Intensity of the southwestward migrations varies from year to year in wide range in dependence on oceanographic conditions.

Fatty acid (FA) and element contents were studied in 14 brands of canned (in its own juice and with sunflower oil) saury (Cololabis saira), a popular product of Russian market. Canned saury is a valuable source of essential polyunsaturated FA - eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3). To obtain personal daily dose of EPA + DHA of 1 g for prevention of cardiovascular diseases, neural and inflammatory disorders one needs to intake from 26 to 76 g of canned saury, as was calculated for studied brands. ICP-OES analysis of 24 elements showed that Pb concentration in one brand and Cd content in most of studied saury samples exceeded standards for fish meat established by the European Commission. However, values of hazard quotient, HQEFA, which estimate benefit-risk ratio of fish intake, indicate that canned saury is safe product for human nutrition.

Lipid fatty acids composition for muscle tissue of pacific saury is determined in dependence on the fish body size. The percentage is 40.97 % of monounsaturated fatty acids and 34.20 % of polyunsaturated fatty acids for small-sized fish and 43.87 % and 31.09 %, respectively, for large-sized fish. The summary content of EPA and DHA is 2.30 g per 100 g of muscle tissue for small-sized fish and 3.77 g/100 g for large-sized fish. Decreasing of the omega-3 fatty acids content in the process of the canned food sterilization does not exceed 5.2 % of the initial amount. The saury of various size could be processed to the canned goods of pate type that excludes the fat losses in the process of broth and fat separation under high temperature. The portion of omega-3 polyunsaturated fatty acids in the canned food from saury is 42.1-46.7%, with average content of EPA and DHA 1.73-2.71 g per 100 g that corresponds to daily requirements of human organism.

Oceanographic conditions influence on saury fishery in the South-Kuril Region is considered on the SST satellite data and fisheries information obtained in August-November of 2002-2014. The SST spatial distribution patterns are compared between the years with high and low landings of saury and the catch efficiency, taking such parameters as the distance of the South Kuril anticyclone eddy from Shikotan Island and the northern Subarctic Front (NSAF) position as quantitative measures of oceanographic conditions. Three basic types of the patterns are defined: 1) long distance to eddy and southern NSAF position; 2) short distance to eddy and northern NSAF position; and 3) short distance and medium NSAF position. The type 1 was observed in 2002, 2003 and 2009 when stable saury fishery began in late August and continued in September-October within the exclusive economic zone of Russia (EEZ) and in November outside EEZ, with low efficiency (CPUE 14-34 t/day, increasing to November). The type 2 was observed in 2004, 2005, 2007, 2008 and 2014 when stable saury fishery began in early August and continued within EEZ till November, with high efficiency (CPUE 31-43 t/day, with maximum in September). The type 3 was observed in 2006, 2011, 2012 and 2013 when stable saury fishery began in late August and continued within EEZ till October, then gradually moved outside EEZ, with medium efficiency (CPUE 20-36 t/day, with maximum in October).

This study investigated the occurrence and distribution of cis-eicosenoic acid (c-20:1) positional isomers in fishes from the Indian Ocean and compared to those from the Pacific and Atlantic Ocean. Lipids were extracted from the edible part of the fish and then methylated. The eicosenoic acid methyl ester fraction was separated from total fatty acid methyl esters by reversed-phase HPLC and quantitatively analyzed using a GC-FID fitted with the SLB-IL111 highly polar GC column. c14-20:1 was used as an internal standard. The results indicated that the highest levels of c-20:1 positional isomers were found in fishes from the Pacific Ocean (saury, 166.95±12.4 mg/g of oil), followed by the Atlantic Ocean (capelin, 162.7±3.5 mg/g of oil), and lastly in fishes from the Indian Ocean (goatfish, 34.39 mg/g of oil). With only a few exceptions, the most abundant 20:1 positional isomer found in fishes of the Indian and Atlantic Ocean was the c11-20:1 isomer (>50%) followed by the c13-20:1 isomer (

Needs for artificial food for salmons considerably increase recently because of foundation of new salmon hatcheries and reconstruction of existing hatcheries in Sakhalin, Kamchatka, Primorye, and Khabarovsk and Magadan regions. In conditions of shortage of Russian-made mixed fodders of high quality and urges toward substitution of imported fodders by domestic ones, highly productive fodders for salmons should be developed using modern scientific knowledge and industrial technologies. Fermented pastas on the base of raw pollock and wastes of other fish processing (chum salmon, saury, herring) are presented as components of mixed fodders for juvenile salmons corresponding by their quality and safety to nutritional requirements of juveniles. Recipes of starting fodders for farming of salmons are proposed with 6 % and 10 % of dry fermentolyzate of these raw materials. These experimental fodders are successfully tested in conditions of salmon hatcheries. The mixed fodder B-1-6 % has lower content of protein (38.5 %) but higher content of lipids (14.5 %) and carbohydrates (37.5 %), as compared with the B-1-10 %, its amino acid composition corresponds to the needs of chum salmon. In the experiments, the feeding coefficients of the experimental fodders (0.64-0.86) were better than those of the fodders Aller Aqua (Denmark) and Dalkorm (Russia) with feeding coefficients 1.00 and 1.44, respectively. The fodders Aller Aqua and Dalkorm caused some pathomorphological changes in digestive system of juvenile chum salmon that reduced quality of juveniles and impeded their growth; the experimental fodder with 6 % of dry fermentolyzate caused mild lipoidal degeneration of liver in reversible form for 15 % of the examined juveniles, but this pathology had no significant effect on quality of the released juveniles. Introduction of high-protein dry fermentolyzate to mixed fodders allows to reduce the portion of fish flour without reducing quality of their protein component, herewith the juveniles vitality increasing.

We investigated the impacts of extensive anthropogenic (high seas driftnet squid fishery) and natural (late 1990s major climate regime shift) events on dominant epipelagic fish, squid, and shark in the central North Pacific Transition Region based on a driftnet survey covering the years 1979–2006. Fishing was conducted by Japan, Korea and Taiwan to target neon flying squid in the period 1979–1992, resulting in a decline in stocks of the target species and non-target species (Pacific pomfret and juvenile blue shark), which were by-catch of this fishery. The catch was found to be at the maximum sustainable yield (MSY) level for neon flying squid, the underfished level for juvenile blue shark, but the overfished level for Pacific pomfret. The MSY of Pacific pomfret indicated that this species is more susceptible to exploitation than previously considered. In response to the late 1990s regime shift, neon flying squid and Pacific saury showed low stock levels in 1999–2002 and 1998–2002, respectively, as a result of reduced productivity in their nursery grounds (the Subtropical Frontal Zone and Kuroshio Extension Bifurcation Region, respectively). On the other hand, Pacific pomfret showed no decreasing trend in stock during the low- and intermediate-productivity regimes because of the high productivity of their main spawning/nursery ground (Transition Zone Chlorophyll Front), which was independent of the regime shifts. Thus, squid and saury appear to be more susceptible to the regime shift than pomfret. We discuss the implications for stock management of the species-specific responses to the fishery and the regime shift.

Drifting gill-nets were for a long time the main research gear for investigating the distribution of Pacific saury Cololabis saira. However, it has proven to be difficult to estimate the absolute abundance of saury using drifting gill-nets due to a lack of knowledge on the survey areas swept by these gill-nets. A mid-water trawl stock abundance estimation has the advantage of being able to estimate the absolute stock abundance before the commercial fishing season begins, whereas the conventional stock abundance estimation based on catch per unit efforts of commercial fisheries must be done after the commercial fishing season has ended. To confirm the practicality of a mid-water trawl to estimate the stock abundance of saury, we conducted a comparative survey in the northwestern Pacific Ocean using both a mid-water trawl and drifting gill-nets. We found that the geographic distribution pattern of catch per unit effort for both the mid-water trawl and driftnets was similar. Using the area-swept method and data on the fishing efficiency of the mid-water trawl obtained in a previous study, we were able to estimate the stock abundance plus confidence limits within the research areas. Our results suggest that the size composition of saury sampled by the mid-water trawl can be considered to approximate the actual size composition of saury.

The lifespan of cephalopods is known to be influenced by the environment, with faster growth and earlier spawning induced by higher than normal water temperatures. However, it is unknown if the Ommastrephid squid, Todarodes pacificus, also exhibits such plasticity, because of difficulties in rearing them. In this study, we reared juveniles of T. pacificus obtained from the wild (Wakasa Bay in the southern Sea of Japan) to adulthood at three different temperatures (13°C, 17°C and 20°C) to understand the impact of water temperature on its lifespan. Mantle lengths of these juveniles ranged from 57.2 to 103.0 mm (about 4–5 months after hatching) at the beginning of the experiment. They were fed a diet of anchovy and saury once or twice daily, and the day/night cycle was set to 12 hours each. Males reared at 17°C and 20°C began to show signs of sexual maturation after 20 days, whereas those reared at 13°C began to mature only after 40 days, and mating behaviour was observed after 30 days at 20°C. Femal...

International audience; Fisheries compete with seabirds for vanishing marine resources, but also produce fishery waste consumed by seabirds. Marine birds may therefore avoid or seek fishing vessels, and have evolved complex, plastic behavioural responses to vessel presence. Understanding these responses is essential to the conservation of a globally declining seabird community. We studied Cape gannets (Morus capensis), which compete with fisheries for reduced sardine (Sardinops sagax) resources in the Benguela upwelling region off South Africa. Using bird-borne GPS trackers coupled with newly-developed ship-radar detectors we show that foraging gannets seldom attended fishing vessels. Rather, they switched from eating scarce sardines or energetically-poor fishery waste to targeting locally abundant saury (Scomberesox saurus). This pelagic fish is brought into the seascape by warm water influx, and is not commercially exploited by fisheries. Cape gannets thereby show dietary plasticity, allowing them to maintain adult body condition and chick growth rates. This diet switch is a strong indicator that Cape gannets forage in an ecologically perturbed marine environment.

Algorithm for calculation of illumination produced by shipboard lights at the sea surface and underwater is developed and implemented with Microsoft© Office Excel software. The surface illumination is calculated for the fishing vessel STR-420 with the light equipment for saury fishery. Irregularity of the lighting around the vessel is shown that depends on the lamps arrangement. Optimal scheme of the lamps arrangement is proposed for a new saury trap with the catch volume > 7000 m 3 . The optimal arrangement provides more regular lighting and therefore larger illuminated area for attraction of fish with positive phototaxis, as saury. Relationship between natural density of saury distribution and its catch per trap is determined for this trap.

The docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) contents of Pacific saury (Cololabis saira), a fatty fish and staple of the Japanese diet, have been reported to decrease after cooking. This study compared the DHA and EPA contents remaining in saury after grilling, pan-frying or deep-frying to center temperatures of 75, 85, or 95 °C, and examined physical loss, lipid oxidation, and thermal degradation as mechanisms of DHA and EPA loss. Temperature changes inside the saury were monitored using thermocouples, while DHA and EPA contents, oxygen radical absorbance capacity, and measurements of lipid oxidation (that is, carbonyl value and thiobarbituric acid value) were determined chemically. Visualization of temperature distribution inside fish samples during cooking revealed large differences in heat transfer among cooking methods. True retention rates in grilled (DHA: 84 ± 15%; EPA: 87 ± 14%) and pan-fried samples (DHA: 85 ± 16%; EPA: 77 ± 17%) were significantly higher than deep-fried samples (DHA: 58 ± 17%; EPA: 51 ± 18%), but were not affected by final center temperatures despite differences in cooking times. Physical loss via cooking losses (grilling and pan-frying) or migration into frying oil (deep-frying) accounted for large quantities of DHA and EPA loss, while lipid oxidation and thermal degradation did not appear to be major mechanisms of loss. The antioxidant capacity of saury was not significantly affected by cooking treatments. The results of this study suggest that minimization of physical losses during cooking may increase DHA and EPA contents retained in cooked Pacific saury.

Sargassum horneri is one of the most important contributors to the rafts of floating seaweed in the waters off the coasts of northeastern Asia. These rafts serve as spawning and nursery grounds for many marine organisms, including Japanese saury and yellowtail. Thus, the details of the attachment/detachment mechanisms of S. horneri are of commercial significance for the aquaculture industry. Here, we describe variations in the attachment strength of S. horneri as it relates to its developmental stage and depth along a bottom gradient. We measured the attachment strength/dislodgement force of S. horneri samples with holdfast detachment in Shidagaura Cove, Shimoda, Japan, from December 2014 to May 2015. After we had determined the dislodgement forces required to detach thalli from the substratum (using a spring scale device) in the field, we transferred released individuals to the laboratory and measured selected morphological traits. Attachment strength was linearly related to the holdfast basal area when thalli were immature (prior to mid-March), but not when they were mature (mid-March to May). Thus, attachment strength was maintained through the reproductive phase and declined thereafter, allowing released thalli to join the drifting raft community. Rafting may be a mechanism by which the species expands its distribution range, as floating thalli continuing to shed germlings that are able to recruit when suitable habitat is encountered. Attachment strengths were greater in the shallows than in deeper water, reflecting the differences in wave forces experienced at different depths.

March 11, 2011 Fukushima nuclear power plant accident has occurred, the last four years, his is the current state of anxiety remains on the consumer. Therefore, 2015 the current progress continues to have continued research for the purpose of resolving the insecurity of fishery in the country. We measured the radiation of the origin of fishery products, by 2015, research was carried out through a number of references to get additional data or studies that influence this to some degree. Create a consumer and one for the seller for the survey to find out the thoughts of both consumers and sellers on fisheries was to create the statistics by direct survey in 2014 year survey meter using PM1405 equipment dynamics of several species of aquatic origin in accordance with the (Taiwan, China, Russia), mackerel, pomfret, hairtail, saury, shrimp, squid measurements of radiation were investigated. The measurement in 2014 was 0.043~0.073 μSv/h. The seller influenced the survey (90%) on fishery products sales, consumer safety, without this fishery (90%), radioactive contamination very high (28%) and the polarization was not as nearly 72%. The study of the stability of the radiation determined by the radiation levels of the aquatic marine products in a comparison the radiation levels result was determined in ICRP below the standard value (1 mSv/y).

Transport of Pacific saury Cololabis saira larvae from spawning to nursery grounds was examined based on datasets from larval distribution surveys during winter seasons 1990–2011. In the surveys, a neuston net was towed for 10 min over broad areas off the southern Pacific coast of Japan. Transport trajectories of saury larvae and temperature they experienced were analyzed based on a numerical particle-tracking model from 1993 to 2011 using satellite-based sea surface current and temperature data. Larval growth during the transport was estimated from the relationship of larval growth to environmental factors obtained in a previous study. Results of the particle tracking experiments indicated that a large amount of saury juveniles (knob length, KnL, 40 mm) were transported to an area south of the Kuroshio axis. Only a relatively small amount (14.6%) of the 40 mm KnL stage juveniles were transported in and around the Kuroshio extension, although it has previously been considered important that the juveniles are transported to the area north of the Kuroshio extension. Abundance of juveniles transported to the area north of the Kuroshio extension indicated a positive relationship to the abundance of medium size class saury in the autumn fishing season. Even though a very small part (3.9%) of hatched larvae were transported to this area, recruitment of the saury population depends on this amount of transported hatched larvae. On the other hand, the high juvenile transport rate to the areas south of the Kuroshio axis may suggest a broad dispersal mechanism to ensure that some larvae find a suitable habitat. Subsequently, the importance of saury in the marine ecosystem as a food item for predatory species in the sub-tropical region is discussed.

BACKGROUND: Fish oil enriched in omega-11 long-chain monounsaturated fatty acids (LCMUFA; C20:1 and C22:1 isomers combined) have shown lipid-lowering and atheroprotective effects in animal models. OBJECTIVE: To perform a first-in-human trial of LCMUFA-rich saury fish oil supplementation to test its safety and possible effect on plasma lipids. METHODS: A double-blind, randomized cross-over clinical trial was carried out in 30 healthy normolipidemic adults (BMI

The Pacific saury (Cololabis saira) supports one of the most important pelagic fisheries in the Northwestern Pacific Ocean. However, changing oceanographic conditions could result in difficulties in predicting fishing grounds and fishery management. We combined a yield-density model and weighted statistical analysis to develop a habitat suitability index (HSI) model to identify the relationship between oceanographic variables and potential habitat. This approach was applied to fishing data from the Chinese saury fishery during the main fishing season (June–November) from 2013 to 2015. The oceanographic variables considered included sea surface temperature (SST), horizontal sea surface temperature gradient (SSTG) and sea surface height (SSH). The HSI model was validated using fishery and oceanographic data for 2016. This study indicated that (1) the yield-density model can be reliably used to fit a curvilinear relation between the suitability index (SI) and SST, SSTG, and SSH, and the optimal habitat conditions for the three variables were obtained; (2) weighted analysis-based boosted regression trees revealed that SSTG had the most important influence on SI each month, followed by SST and SSH; and (3) approximately 70% of the fishing effort occurred in the areas where HSI > 0.5 in each month. Results of this study could help to further understand the effects of oceanographic conditions on habitat distribution and provide a way to forecast saury fishing grounds.

Sea surface temperature (SST) is an important factor that affects the changes of marine fishery resources. In this paper, the characteristics of distribution and variation in sea surface temperature was retrieved in northwestern Pacific Ocean by MODIS from 2008 to 2017. The results showed that the distribution of SST in northwestern Pacific Ocean was found to be characterized by regional and seasonal changes. Annually, periodical changes in SST was found unconspicuously, and spatially, the SST high value area showed a trend of moving from high-latitude to low-latitude. In August each year, there seemed to be a temperature boundary at 40°N, and the boundary will move south in September. Finally, we analyzed the SST distribution of the two main fishing periods of Cololabis saira in August and September each year, and preliminarily explained the cause of the "fish shortage" of saury recently years in Japan. The long-term variations in SST were discussed macroscopically in this paper, and this could give a new insight into fishing industry research in the Northwest Pacific.

During breeding, seabirds are central place foragers and are sensitive to changes in local prey availability. As the breeding season progresses, foraging behavior and distribution is expected to change in response to possible changes in local prey availability. In addition, adult gender, and the increasing nutritional demands of a growing chick may also influence the foraging behavior of individuals. At present, relatively few studies have assessed the foraging behavior of adult birds during the late post-guard stages of chick rearing. Through a combination of GPS tracking and diet sampling we investigated the foraging distances, spatial distribution, and prey composition of adult Cape gannets (Morus capensis) during the guard and post-guard stages of chick rearing. We found no clear evidence for consistent sex-specific differences in foraging distances and spatial distribution during the guard stage, although marginal differences in the location of core foraging areas during the post-guard stage were apparent. Results, however, revealed a clear increase in foraging range from the early guard to the late post-guard stage of chick rearing. During December the diet was comprised almost exclusively of anchovy (Engraulis encrasicolus), the proportion of which had decreased significantly in the diet by January. This was mirrored by a substantial increase in the proportion of saury (Scomberesox saurus). These results suggest that Cape gannets show flexibility in the foraging behavior and diet, which may be related to changes in the abundance and distribution of prey or may reflect changes in the energetic requirements of the growing offspring. This study provides the first assessment of Cape gannet foraging behavior and spatial distribution during the post-guard stage of chick rearing. The importance of considering intra-annual variability in foraging distribution when using seabird tracking data in trophic and marine spatial planning studies are highlighted.

The purpose of this study was to develop sodium reduced foods for 10 representative high sodium foods often served in the food service industry, and to conduct sensory evaluation on the foods. The foods are kimchi, cucumber salad, banquet noodle, seaweed soup, ahuk soup, pork kimchi stew, red pepper paste pork chops, beef bulgogi, grilled mackerel and saury stew selected based on data from the 2010 national health and nutrition examination survey. The sodium contents of chinese cabbage kimchi were 688.1 mg in the control, 587.3 mg in the 15% reduced sodium sample group (level 1), and 486.5 mg in the 30% reduced sodium sample group (level 2). The corresponding sodium contents of cucumber salad were 406.4 mg, 345.5 mg, and 284.6 mg. The sodium contents of banquet noodle were 1080.2 mg, 912.2 mg, and 765.8 mg, respectively. The sodium contents of seaweed soup were 459.4 mg, 392.1 mg, and 333.0 mg, respectively. The sodium contents of ahuk soup were 615.3 mg, 534.9 mg, and 434.4 mg respectively. The sodium contents of pork kimchi stew were 1156.2 mg, 988.3 mg, and 820.2 mg respectively. The sodium contents of grilled mackerel were 624.6 mg, 557.4 mg, and 456.9 mg respectively. The sodium contents of red pepper paste pork chops were 723.7 mg, 615.0 mg, and 505.3 mg, respectively. The sodium contents of beef bulgogi were 678.3 mg, 561.9 mg, and 473.3 mg, respectively. The sodium contents of saury stew were 676.0 mg, 574.6 mg, and 470.9 mg respectively. Sensory evaluation was conducted with a total of 30 samples consisting of 10 control food groups, 15%, and 30% reduced sodium food groups. Results showed sodium reduction up to level 1 or 2 in chinese cabbage kimchi, cucumber salad, pork kimchi stew, red pepper paste pork chops, beef bulgogi, grilled mackerel and saury stew. However, the soups and noodles showed significant differences between the control and the 15% reduced sodium (level 1) food groups, specifically in banquet noodle, seaweed soup, ahuk soup.

Although Japan is one of the largest seafood-consuming countries, with various types of seafood products traded throughout the nation, few studies have explored how this market is integrated from the aspect of market price. Because Japanese consumers in different regions have different preferences for seafood, we focused our study to see how the regional seafood retail markets (Tokyo, Osaka, Nagoya, Sapporo, and Fukuoka) are integrated for 10 major seafood products (horse mackerel, short-necked clams, yellowtail, scallops, cuttlefish/squid, flounder, tuna, mackerel, saury, and octopus) consumed in Japan. We applied the relatively new Phillips–Sul convergence test for our analysis. For most of the seafood products investigated in this study, our results indicate that the Japanese regional seafood markets cannot be integrated as a whole and that marketing strategies need to consider the peculiar characteristics of the regional seafood markets.

Foraging habits of predators can reveal patterns in prey ecology and guide ecosystem-based management by informing species interactions. This study describes the diet habits of albacore tuna in three regions (north, central, south) of the California Current System (CCS) and estimates the total predation mortality imposed on twenty prey taxa. The northern CCS was defined by predation on decapods, euphausiids, anchovy and hake. The central CCS was defined by predation on squid, hake and Pacific saury. The southern CCS was defined by predation on anchovy. We estimate North Pacific albacore consumed each year, on average, 54,000 mt of decapods and euphausiids, 43,000 mt of cephalopods, 84,000 mt of juvenile hake, 1600 mt of myctophids, 21,000 mt of juvenile sardine, 10,000 mt of juvenile rockfishes, almost 43,000 mt of Pacific saury, and over 107,000 mt of juvenile anchovy. While variability in predation certainly exists, this and prior studies show that diet habits of albacore are fairly stable through time. The northern CCS appears to be a more significant source of energy for albacore. When designing ecosystem-based approaches to the management of CCS-based fisheries, we recommend that the forage contribution of saury, hake and anchovy to the albacore population be considered.

Electron spin resonance (ESR) analysis was conducted for eight different kinds of dried seafood products to investigate their gamma-irradiation status. The specimens consisted of 0∼10 kGy-irradiated bones, which included five dried fishes (plaice, hairtail, saury, herring, and dried filefish) and three dried mollusks (beca squid, dried squid, and mitra squid) without flesh or marrow. ESR analysis showed that irradiated specimens exhibited typical asymmetric signals as compared to non-irradiated specimens. ESR signal intensities of all dried fishery samples significantly in- creased depending on irradiation dose, whereas hydroxyapetite radicals clearly appeared in irradiated plaice, saury, and hairtail. In comparing hydroxyapatite (HA) ratio, irradiated hairtail showed a greater hydroxyapatite-radical gen- eration rate than plaice and saury, and the HA ratio significantly increased with elevated irradiation dose. However, all irradiated plaice and hairtail samples, including 5 and 10 kGy-irradiated saury, showed radiation-derived radicals, whereas filefish and mollusks did not. From the results, ESR spectroscopy was found to have potential to be applied for identifying irradiated plaice, hairtail, and saury, which all contained bones.

The Pacific saury is often preserved using salt, which helps to maintain the main taste component of the fish, inosinic acid (IMP). IMP is degraded by the IMP-degrading enzyme IMPase, the activity of which may be differentially affected by the type of salt used for preservation. Understanding the effects of these salts will help to maintain the desired amount of IMP to preserve the taste of saury. In saury, 40 % of all muscle is dark muscle, thereby; therefore, the effect of various salts on IMPase activity should be investigated in both the white and dark muscle. In this study, the IMPase activity in the white and dark muscle of saury was compared under different processing conditions, and the most suitable salts for processing were determined. There was almost no difference in IMPase activity between the white and dark muscle with respect to variations in pH, temperature, and salt type, indicating that the two muscle types could be processed under the same conditions. In addition, IMPase activity in the dark muscle of saury was promoted by MgCl2 and MgSO4, indicating that salt manufactured using an ion-exchange membrane to remove SO 4 2− and to decrease Mg2+ is most suitable for use in saury preservation.

Histamine (HA) is an essential test item for fishery samples. However, the fast and effective determination of HA is difficult due to its simple structure and small molecular size. In this study, a sensitive and specific monoclonal antibody against p-nitrobenzoylated histamine (NPHA), which can be easily obtained from the reaction of HA and p-nitrobenzoic acid N-hydroxysuccinimide ester (PNBA-OSu) under mild conditions, was generated for the first time. Based on this mAb, an immunochromato-graphic assay strip (ICA strip) using a colloidal gold nano particles-antibody (GNPs) probe for rapid detection of HA in saury samples was established. After screening the coating antigens and optimization of analytical parameters, a heterologous coating based ICA strip exhibited the most excellent detection ability with a visual detection limit (VDL) of 6.0 mg kg−1 in qualitative experiments and a detection limit (by a strip reader) of 1.0 mg kg−1 in semi-quantitative experiments for saury samples, with no cross-reactivity with HA analogs. Good correlation between the ICA strip with liquid chromatography-tandem mass spectrometry was achieved for spiked and naturally contaminated saury samples. Overall, this method is suitable for screening of HA residue for large scale fish samples in a quick, simple and low-cost manner.

BACKGROUND AND AIMS: Concentrated fish oils, containing a mixture of long-chain monounsaturated fatty acids (LCMUFA) with aliphatic chains longer than 18 C atoms (i.e., C20:1 and C22:1), have been shown to attenuate atherosclerosis development in mouse models. It is not clear, however, how individual LCMUFA isomers may act on atherosclerosis. METHODS: In the present study, we used saury fish oil-derived concentrates enriched in either C20:1 or C22:1 isomer fractions to investigate their individual effect on atherosclerosis and lipoprotein metabolism. LDLR-deficient (LDLr(−/−)) mice were fed a Western diet supplemented with 5% (w/w) of either C20:1 or C22:1 concentrate for 12 wk. RESULTS: Compared to the control Western diet with no supplement, both LCMUFA isomers increased hepatic levels of LCMUFA by 2~3-fold (p < 0.05), and decreased atherosclerotic lesion areas by more than 40% (p < 0.05), although there were no major differences in plasma lipoproteins or hepatic lipid content. Both LCMUFA isomers significantly decreased plasma CRP levels, improved Abca1-dependent cholesterol efflux capacity of apoB-depleted plasma, and enhanced Ppar transcriptional activities in HepG2 cells. LC-MS/MS proteomic analysis of lipoproteins (HDL, LDL and VLDL) revealed that both LCMUFA isomer diets resulted in similar potentially beneficial alterations in proteins involved in complement activation, blood coagulation, and lipid metabolism. Several lipoprotein proteome changes were significantly correlated with atherosclerotic plaque reduction. CONCLUSIONS: Dietary supplementation with the LCMUFA isomers C20:1 or C22:1 was equally effective in reducing atherosclerosis in LDLr(−/−)mice and this may partly occur through activation of the Ppar signaling pathways and favorable alterations in the proteome of lipoproteins.

Pacific saury ( Cololabis saira ) is an important fisheries resource and commercial species of Taiwanese deep-sea saury stick-held dip net fishery in the Northwestern Pacific Ocean. In this study, the logbook data of a 3-year (2006–2008) Taiwanese Pacific saury fishery and corresponding satellite-derived MODIS sea surface temperature (SST) data were analyzed to detect SST fronts and examine their influence on the spatio-temporal distribution of Pacific saury. The fronts were identified by the Cayula–Cornillon single-image edge detection algorithm. The results show that low frequency of SST fronts is associated with lower CPUEs during the early fishing season (June–August), while high frequency of SST fronts is associated with higher CPUEs during the peak fishing season. When fishing locations of Pacific saury are close to the SST fronts, higher CPUEs are observed. Results of this study provide a better understanding of how SST fronts influence distribution of Pacific saury and improve the basis of fishing ground forecasting.

Lagrangian fronts (LFs) in the ocean are defined as boundaries between surface waters with strongly different Lagrangian properties. They can be accurately detected in a given velocity field by computing synoptic maps for displacements of synthetic tracers and other Lagrangian indicators. We use Pacific saury catch and location data for a number of commercial fishery seasons in the region of the northwest Pacific with one of the richest fishery in the world. It is shown statistically that the saury fishing grounds with maximal catches are not randomly distributed over the region but located mainly along the sharp LFs where productive cold waters of the Oyashio Current, warmer waters of the southern branch of the Soya Current, and waters of warm-core Kuroshio rings converge. Computation of those fronts in altimetric geostrophic velocity fields both in the years with the First and Second Oyashio Intrusions shows that in spite of different oceanographic conditions LF locations may serve as good indicators of potential fishing grounds. Possible biophysical reasons for saury aggregation near sharp LFs are discussed. We propose a mechanism for effective export of nutrient rich waters based on stretching of material lines in the vicinity of hyperbolic objects in the ocean. The developed method, based on identifying LFs in any velocity fields, is quite general and may be applied to find potential fishing grounds for the other pelagic fish.

We introduce the concept of Lagrangian fronts (LFs) in the ocean and describe their importance for analyzing water mixing and transport and the specific features and differences from hydrological fronts. A method of calculating LFs in a given velocity field is proposed. Based on altimeter velocity fields from AVISO data in the northwestern Pacific, we calculate the Lagrangian synoptic maps and identify LFs of different spatial and temporal scales. Using statistical analysis of saury catches in different years according to the Goskomrybolovstvo (State Fisheries Committee of the Russian Federation), we show that LFs can serve as good indicators of places that are favorable for fishing.

1. Bioeconomic models are increasingly used to provide benchmarks for harvest levels in wildlife and natural resource management, yet uncertainties related to model structure are underexplored. We investigate the importance of a range of uncertainties with a focus on model structure and life histories when estimating bioeconomic target reference point (TRPs) and assess the policy implications of ignoring these uncertainties. 2. We use three contrasting case studies to investigate the interactions between model, observational and process errors related to life-history parameters: the short-lived Japanese common squid Todarodes pacificus and Pacific saury Cololabis saira, and the slow-growing Patagonian toothfish Dissostichus eleginoides. We developed a simulation framework to test the harvest strategies resulting from bioeconomic TRPs under various assumptions about model structures and parameters. 3. We found the relative importance of different types of uncertainties affecting precision and accuracy of the model outputs varied according to the life-history traits. Little difference in TRP estimates was found between simple vs. complex population models for saury, while large differences were found for toothfish. The assumptions made about stock structure for squid not only resulted in different TRP estimates (generally, smaller for the multistock models), but also different economic outcomes depending on the balance of effort allocation between stocks. 4. Synthesis and applications. We use models similar to those used in the actual management of three case study species to explore the effects of interacting uncertainties on the management advice. We show that the interactions between structural elements of the models lead to very different management advice, depending on the life history of the species concerned. For the long-lived toothfish, life-history and gear selectivity parameters interacted strongly. For the short-lived squid which is managed as two stocks, spatial fishing effort allocation, correlation of environmental drivers between stocks and differential stock productivity interacted, producing very poor economic performance if assumptions about stock structure are incorrect. The key message for model-based natural resource management is that it is vital to investigate the major uncertainties related to model structure, process and estimation errors simultaneously, because they interact to produce non-intuitive results.

Regular fish/fish oil consumption is widely recommended for protection against cardiovascular diseases (CVD). Fish and other marine life are rich sources of the cardioprotective long-chain n-3 polyunsaturated fatty acids (n-3 PUFA) eicosapentaenoic acid (C20:5 n-3; EPA) and docosahexaenoic acid (C22:6 n-3; DHA). The lipid content and fatty acid profile of fish, however, vary greatly among different fish species. In addition to n-3 PUFA, certain fish, such as saury, pollock, and herring, also contain high levels of long-chain monounsaturated fatty acids (LCMUFA), with aliphatic tails longer than 18 C atoms (i.e., C20:1 and C22:1 isomers). Compared with well-studied n-3 PUFA, limited information, however, is available on the health benefits of marine-derived LCMUFA, particularly in regard to CVD. Our objective in this review is to summarize the current knowledge and provide perspective on the potential therapeutic value of dietary LCMUFA-rich marine oil for improving CVD risk factors. We will also review the possible mechanisms of LCMUFA action on target tissues. Finally, we describe the epidemiologic data and small-scaled clinical studies that have been done on marine oils enriched in LCMUFA. Although there are still many unanswered questions about LCMUFA, this appears to be promising new area of research that may lead to new insights into the health benefits of a different component of fish oils besides n-3 PUFA.

The results of long-term studies of the spatial distribution, size composition, and spawning intensity of the Pacific saury Cololabis saira in open waters of the North Pacific Ocean and the northeastern part of the Pacific Ocean off the west coast of North America are presented. In the open waters of the Pacific Ocean, saury forms aggregations early in summer; intraseasonal changes in their distribution pattern have been identified. Migrations of Pacific saury stocks in the northeastern part of the Pacific Ocean were considered, and assumptions about their causes were made. The differences in the size composition of Pacific saury in different parts of the range are associated with the peculiarities of occurrence of favorable conditions for the formation of aggregations. Intensive spawning of Pacific saury in the northeastern part of the Pacific Ocean is observed in winter and spring, and that in open waters is observed in summer. The distribution of the early progeny of Pacific saury is associated with the systems of currents; its findings in the extreme northern regions in the 1980s are explained.

Photostimulated luminescence (PSL) and thermoluminescence (TL) analyses were conducted for the detection of different gamma-irradiated dried fishes (mussel, squid, beka squid, mitra squid, plaice, and saury) at 0, 1, 5 and 10 kGy. For TL analysis, the contaminating silicate minerals were obtained by density separation or acid hydrolysis treatment. PSL determinations indicated that all the non-irradiated samples showed PSL photon counts/60 s (PCs) lower than 700 PCs (negative), but the irradiated mussel sample at 5 and 10 kGy were only possibility identified showing higher than 5000 PCs (positive). Irrespective of sample kinds and methods of mineral separation, all the non-irradiated samples showed TL glow curves in low-intensity with a maximum peak only after 250°C. However, all the irradiated samples produced TL glow curves in high intensity with a maximum peak particularly in the temperature range of 150~250 o C. In conclusion, more distinguishable TL results (glow curve, TL ratio (TL1/TL2)) were obtained from the marker minerals separated by acid hydrolysis rather than density method.

An ecosystem based bioenergetics model was used to investigate responses of Pacific saury (Cololabis saira) to global warming. The model was forced by the projected sea surface temperature (SST) generated by climate models that formed the bases for the Intergovernmental Panel on Climate Change 4th Assessment Report (IPCC-AR4). Twelve climate models, which reproduced the Pacific Decadal Oscillation well in comparison with observations, were selected and B1, A1B, and A2 emissions scenarios were used. In total, thirty-three ensemble simulations were conducted of which, twenty-four (73%) showed a decrease of wet weight of Pacific saury. The migration pattern was modified in eleven (33%) cases. In these cases, higher SST and size reduction under global warming prevented or delayed the southern migration of saury in winter. As a result, egg production was enhanced by the higher availability of prey plankton in the modified spawning region. A case study to separate the direct temperature effects was conducted, in which prey plankton density was assumed to be the same as the control run. The results suggest that a SST increase will directly reduce juvenile growth while a prey plankton density decrease has an influence on the growth of adults and migration pattern, and hence egg production. Modeling ecological responses of Pacific saury (Cololabis saira) to future climate change and its uncertainty Shin-ichi Ito1, Takeshi Okunishi1, Michio Kishi3, Muyin Wang4 1 AORI, Univ. of Tokyo, 2Fisheries Research Agency, 3 Hokkaido University, 4 University of Washington

The purpose of this study was to investigate the diffusion process and background to regional meals, the creation of sale-consumption activity, and regional characteristics focusing on the distribution and consumption of fish species. Sauries were not part of traditional regional fishery in Okinawa. However, some of the saury catch, which is used as bait in pelagic fishery, began to be converted to food use from the late 1950s. In the 1960s, traders in the Ryukyu Islands (the former regional name for Okinawa which was used before the reversion to Japan) began to import food commodities from Japan. Since the reversion of the Ryukyu Islands to Japan in 1972, traders from Japan proper entered the food distribution sector in Okinawa. Full-scale commodity trading in sauries was gradually established. At present, sales of raw or fresh sauries are diffusing. Eating habits and the socioeconomic conditions of Okinawa differ from those in the rest of Japan and they are reflected in the methods of sales and trends in cooking and consuming sauries.本研究は，沖縄県を対象として，当該地域の漁業活動で対象とされていない魚種の流通・消費を取り上げて，地域の食卓への普及過程とその背景，販売・消費活動の展開や地域的特徴を明らかにすることを目的とする．遠洋漁業用餌のサンマの一部が1950年代末から食用に転用され，1960年代には琉球の業者が食用商材を本土から集荷を開始していた．日本への復帰を契機に，本土の業者も流通に参入し，本格的にサンマ商材が扱われるようになった．今日では生・生鮮品の販売も普及している．沖縄の食習慣や社会・経済的条件の影響を受けて，本土とは異なるサンマの販売形態や調理・消費動向が確認された．

Regions rich in nutrients with food grounds for zooplankton, the main feeding resource of pelagic fish, are locations of fishing grounds. Favorable condi� tions are usually formed in the subarctic frontal zones at the boundaries between cold and warm currents and in the periphery of mesoscale eddies. These are regions with high mechanical energy and intense horizontal mixing, in which phytoplankton, the food for zoop� lankton, can concentrate. Numerous investigations in different seas and oceans confirm that fronts and eddies are formations in which favorable conditions are formed for reproduction of plankton and growth of fish [1–3]. In the northwestern part of the Pacific Ocean east of Hokkaido Island (Japan) and the South� ern Kuril Islands, the waters of the cold subarctic Oyashio Current mix with the waters of the warm Kuroshio Current. Owing to the high concentration of nutrients in the cold waters of the Oyashio and high tides facilitating reproduction of phytoplankton in the surface waters, this region is known as one of the rich� est fishing locations in the world. The objective of this work is to distinguish the Lagrangian coherent structures in the ocean at the fronts (boundaries between the waters of different ori� gins), along which favorable conditions for fishery are formed. In the language of the theory of dynamic sys� tems, these structures are called unstable manifolds of hyperbolic points of nonstationary flow. The geo� strophic velocity field was calculated from the data of satellite altimetry. By calculating the displacements D of a large number of particles during a specific time period, one can plot a synoptic chart of this value for any region in which the fronts and the curves of the local minimum of D are clearly pronounced that visu� alize the strongest unstable manifolds in the region. It is shown in this paper that the vessels with the maximum catches of saury in the fall of 2002 and 2004 were located mainly along the unstable manifold depicting the Oyashio front at that period of time. We solve the equation for the advection of a passive admixture

The Atlantic saury Scomberesox saurus saurus (Walbaum) is a widely distributed epipelagic nekton species in the north Atlantic. It is considered one of the most abundant small pelagic species in the north Atlantic and is of increasing interest to commercial fisheries in American and European countries. Ageing of Atlantic saury is difficult, annual marks in otoliths, scales and other structures are often not present or are difficult to interpret, resulting in non-robust estimations. Growth of the Atlantic saury, from the northeastern Atlantic Ocean was studied by examining otoliths and scales for the presence of putative annual and daily growth marks. A description of Atlantic saury saggital otolith microstructure is given. No annual structures were observed on scales or otoliths. Counts of otolith micro-increments suggest that Atlantic saury exhibit a much faster growth rate than previously reported. Micro-increment counts ranged from 113 to 258 in fish from 110 mm to 288 mm of body size, suggesting that Atlantic saury is a short lived species. Assuming that otolith growth increments are deposited at a rate of one per day, average growth rates from hatching up to eight months old exceeded 1 mm/day. The saury population available for exploitation in the northeast Atlantic is dominated by fish that are most likely less than one year old. Management of short-lived, forage species require special considerations and represents a challenge to fishery science.