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Recreational angling is a popular leisure activity globally and can be a threat or useful conservation tool depending on the management strategy. Miyabe charr Salvelinus malma miyabei is an endemic fish that inhabits Lake Shikaribetsu, and a management program was established to harmonise recreational fishery and conservation. To examine the suitability of this program, population assessment was conducted with the cooperation of anglers. The population size in 2014 as assessed by tag-and-release angling was estimated to be 105,300 [95% confidence interval (CI) 37,300–178,600], much higher than the reported estimate in 1995. Further, angling mortality was estimated to be quite low. Moreover, no decreasing population trend was detected on analysing 8 years of anglers’ catch data. Consequently, angling has facilitated stock assessments of Miyabe charr under the current program. This case is a good example of recreational angling acting as a conservation tool under appropriate management. 相似文献
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Makiguchi Y Konno Y Konishi K Miyoshi K Sakashita T Nii H Nakao K Ueda H 《Fish physiology and biochemistry》2011,37(2):273-284
The movements of 28 adult chum salmon, Oncorhynchus keta (Walbaum) tagged with electromyogram (EMG) transmitters were tracked along the Toyohira river, Hokkaido, Japan, in October
of 2007 and 2008 to investigate and evaluate the upstream migratory behavior through the protection bed and fishway of ground
sills. The approach time of fish that ascended successfully through the protection bed and fishway was shorter than that of
unsuccessful fish. The unsuccessful fish were observed to swim in currents with high water velocity and shallow water depth
at swimming speeds that exceeded their critical swimming speed (U
crit) during the approach to these structures. In consequence, unsuccessful fish frequently alternated between burst and maximum
sustained speeds without ever ascending the fishway, and eventually became exhausted. It is important that fishway are constructed
to enable chum salmon to find a passage way easily, so that they can migrate upstream rapidly without wasting excessive energy. 相似文献
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To develop effective strategies for managing biological invasions, it is important to understand and be able to predict patterns of invasion and range expansion, and particularly the rate of spread and factors controlling this rate. To predict the spatial dynamics of invasion by an alien bumblebee (Bombus terrestris) in Hokkaido, Japan, we explicitly constructed a stochastic spatio-temporal model that incorporates immigration and establishment processes. Using a Bayesian approach, we parameterized the model based on spatio-temporal presence/absence data collected by citizen volunteers and used the model to predict control of the near-future spread of the bumblebee under several management strategies. The range expansion dynamics of B. terrestris were significantly negatively affected by two aspects of environmental heterogeneity: the land-use pattern (the proportion of woodland) and climate (the snow depth). Of the several spatial management strategies, suppressing the outlying (edge) colonies would be the most efficient strategy to reduce the bumblebee’s spread, irrespective of the level of effort, and would significantly slow the bumblebee’s range expansion during the next 30 years. The modeling approach employed in the present study will be broadly useful for studying real-world biological invasion problems, for which prediction of the progress of an invasion, even in the very near future, is urgently needed to support effective spatial management options and countermeasures. In addition, the model demonstrates that incorporating the dynamics of environmental heterogeneity is a fundamental requirement for prediction and risk assessment during biological invasions, especially in the context of recent rapid changes in the environment at regional and global scales. 相似文献
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Taisei Nagata Mamoru Sameshima Taku Uchikawa Natsumi Osafune Takeshi Kitano 《Fisheries Science》2017,83(2):273-281
Episodes of summer mortality of the Kumamoto oyster Crassostrea sikamea are a major problem for its cultivation. Expression of the heat shock protein 70 (HSP70) is induced by various environmental stresses, including heat. We cloned and sequenced hsp70 complementary DNA from C. sikamea to investigate the relationship between hsp70 expression and heat tolerance in this oyster. Quantitative real-time polymerase chain reaction was performed using gill tissue dissected from oysters before and after heat shock for 1 h. The results showed hsp70 expression was faster and greater in oysters cultured at 20–22 °C than at 10–12 °C, and survival was lower among oysters cultured at 20–22 °C than at 10–12 °C. Moreover, heat tolerance was investigated by a 1-h pre-heat treatment, followed by exposure to heat shock conditions 5 days later. Survival was higher and hsp70 expression was notably lower in oysters that received the pre-heat treatment compared with those that did not. We conclude that a pre-heat treatment of only 1 h may be useful for inducing heat tolerance in C. sikamea, and that a low level of hsp70 expression after heat shock is an important index in selecting for high heat tolerance in these oysters. 相似文献
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Improvement in recruitment of Japanese sardine with delays of the spring phytoplankton bloom in the Sea of Japan
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Taketoshi Kodama Taku Wagawa Seiji Ohshimo Haruyuki Morimoto Naoki Iguchi Ken‐Ichi Fukudome Tsuneo Goto Motomitsu Takahashi Tohya Yasuda 《Fisheries Oceanography》2018,27(4):289-301
To evaluate the impact of temporal variation of primary productivity on the recruitment of Japanese sardine (Sardinops melanostictus) in the Sea of Japan, the phenology of sea surface phytoplankton abundance was estimated from 8 day multiple satellite (SeaWiFS, MODIS‐Aqua, MERIS, and VIIRS) derived sea surface chlorophyll (SSChl) a concentrations from January 1998 to December 2015. Because relationships between SSChl a and in situ chlorophyll a concentrations were significantly different among periods based on the satellite combinations used, maximum and minimum SSChl a concentrations of 1 year were relativized as 1 and 0, respectively. Spatio‐temporal variation of relativized SSChl a concentrations was determined by using empirical orthogonal function (EOF) analysis. Scores in the first EOF mode denoted the basin‐scale variations of SSChl a concentrations in the Sea of Japan, and the major peak from the end of February to the end of May displayed the spring bloom. The logarithm of recruitment per spawner (LNRPS) for sardine was positively affected by delays in the start and end dates of the spring phytoplankton bloom. The delay of the date of the lowest sea surface temperature contributed to the delay of the end of the spring bloom during the period 1998–2015 and elevated the LNRPS during the period 1982–2015. Sardine spawns in the southern Sea of Japan from April to May, hence, delays of the spring bloom prolonged its overlap with sardine larval periods, and thus improved the recruitment of Japanese sardine in the Sea of Japan. 相似文献
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Nakamura K Miyasho T Nomura S Yokota H Nakade T 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2012,74(6):751-756
We performed proteomics analysis of the cerebrospinal fluid (CSF) of healthy dogs and dogs with meningoencephalitis of unknown etiology (MUE). By comparing two-dimensional electrophoreses (2DE), an upregulated spot was found in MUE dogs. This protein was identified as a neuron-specific enolase (NSE) by analysis with MALDI-TOF mass spectrometry. In comparing dot blots using an antibody against NSE, the NSE levels in the CSF of MUE dogs was significantly higher than that of the controls. NSE is a diagnostic marker of neuroendocrine tumors, brain injury and spinal cord trauma in humans. It seems that the NSE concentration in the CSF is increased by cellular destruction in canine encephalitis. Though elevation of NSE may not be specific in canine encephalitis because the NSE level was increased in other CNS diseases, further study including measurement with serum is necessary. 相似文献
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WULIJIDELIGEN Takayuki ASAHINA Kazushi HARA Kensuke ARAKAWA Hiroyuki NAKANO Taku MIYAMOTO 《Animal Science Journal》2012,83(10):704-711
The purification and characterization of a bacteriocin produced by Leuconostoc mesenteroides strain 406 that was isolated from traditional Mongolian fermented mare's milk, airag, were carried out. Leuconostoc mesenteroides strain 406 was identified on the basis of its morphological and biochemical characteristics and carbohydrate fermentation profile and by API 50 CH kit and 16S ribosomal DNA analyses. The neutral‐pH cell‐free supernatant of this bacterium inhibited the growth of several lactic acid bacteria and food spoilage and pathogenic organisms, including Listeria monocytogenes and Clostridium botulinum. The bacteriocin was heat‐stable and not sensitive to acid and alkaline conditions, but was sensitive to several proteolytic enzymes such as pepsin, pronase E, proteinase K, trypsin, and α‐chymotrypsin, but not catalase. Optimum bacteriocin production (4000 activity units/mL) was achieved when the strain was cultured at 25°C for 24–36 h in Man Rogosa Sharpe medium. The bacteriocin was partially purified by ammonium sulfate precipitation (80% saturation), dialysis (cut‐off MW: 1000), and gel filtration chromatography. Sodium dodecyl sulfate‐polyacrylamide gel electrophoresis revealed that the bacteriocin had a molecular weight of approximately 3.3 kDa. To our knowledge, this is the first report of the isolation of a bacteriocin‐producing Leuconostoc strain from airag. An application to fermented milks would be desired. 相似文献
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A temporal pattern of reproductive activities of biological resources is essential information for the implementation of specific
seasonal closures. First we investigated the relationship between the female pleonal expansion and female reproductive condition
(i.e., non-ovigerous, ovigerous, or with spermatophores) to clarify the morphological characteristics of female coconut crabs
that were able to mate. Second, we mated females with males in captivity to examine the relationship between the degree of
female pleonal expansion and mating success. The index of pleonal expansion (ratio of inter-tergite distances to thoracic
length) was significantly different among female reproductive conditions; females with spermatophores just before egg extrusion
had the most expanded pleon. In the mating trials, all females showing index values higher than 0.35 mated with males. These
results indicate that the female pleonal expansion has a strong relation to reproductive activities of females and can be
applied as a morphological criterion for selecting females being able to mate. Next, we investigated whether reproductive
activities of female coconut crabs are related to the lunar cycle. The reproductive activities were synchronized with the
lunar cycle, and most females mated and extruded eggs around the new moon phase. These results have considerable implications
for resource management and aquaculture for this species. 相似文献