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1.
LisbethPlassa 《海洋水产研究》2001,22(4):18-20
Activities1994In 1994 Peter Gullestad(Present Director General of Fisheries in Bergen) headed a Norwegian delegationvisiting China.In his presentation of“The N orwegian exp erience in fisheries management and control” - hestressed the fact that overcapacity is“the root of all evil”.He also underlined that it is important not only toset up a legal system for fisheries management but also to establish reliable catch statistics.He further morepointed out that good scientific advice is th… 相似文献
2.
What are the drivers of the occurrence of illegal fishing and conservation barriers of sturgeons in the Caspian Sea?
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Seyed Mostafa Aghilinejhad Saeid Gorgin Daan van Uhm Ramtin Joolaie Rasoul Ghorbani Seyed Yousef Paighambari Jahangir Mohammadi Ali Jalali 《水产资源保护:海洋与淡水生态系统》2018,28(3):690-701
3.
Thanaset Thongsaiklaing Wimonsiri Sehawong Anchanee Kubera Lertluk Ngernsiri 《Fisheries Science》2014,80(3):589-601
Indian rock oyster Saccostrea forskali is an important commercial species in Thailand. In this study, its full-length α-amylase (SfAmy) cDNA nucleotide sequence was investigated. The SfAmy cDNA was 1,689 bp long and contained a 1,563-bp open reading frame encoding 520 amino acid residues, including a 17-amino acid signal peptide. The molecular mass and the estimated isoelectric point (pI) of the deduced mature S. forskali α-amylase (SfAMY) were 55.948 kDa and 6.45, respectively. The deduced protein sequence showed 45–88 % identity to other mollusk AMYs. The molecular weight was confirmed by the weight of the purified native enzyme. The specific activities of crude and purified native enzymes toward 1 % starch were 29.53 and 187.42 U/mg. In addition, the obtained recombinant SfAMY also showed activity in digesting 1 % starch. The specific activities of the crude and purified recombinant proteins were 11.8 and 46 U/mg. Both enzymes showed optimal activity temperature at 40 °C but their optimum pH values were different, 6.0 for the native and 5.0 for the recombinant. The expression of SfAmy examined by RT-PCR showed the highest levels in the digestive gland but none was observed in the adductor muscle. 相似文献
4.
The collapse in recruitment of the European eel (Anguilla anguilla) since the early 1980s has been ascribed to possible overfishing, poisoning, parasitism, habitat loss and changes in ocean circulation. It is unclear which mechanism is most important, and firm data are lacking to make an assessment of the factors that apply over the full continental range. On the other hand, the recruitment of the American eel (A. rostrata) has declined along the western Atlantic at about the same time. This suggests a candidate mechanism that can affect both species together. A change in ocean climate may be a likely explanation, which is supported by a possible link between the North Atlantic Oscillation and one important recruitment index. However, it is unsafe to discard the other possible mechanisms because of lack of evidence. Habitat loss, in particular, may be important. We review over a century of evidence to suggest how the eel may have declined through progressive habitat loss that accelerated in the early 1980s as the result of economic development linked with hydrological changes. Although no single line of evidence can definitely prove one hypothesis for the eel decline, the total body of information may indicate a pronounced susceptibility in the southwest corner of the continental range closest to the Sargasso Sea that has been particularly affected by drought and dam construction. The sexual dimorphism of the species together with the energy requirements of the spawning migration may provide insight to explain the population collapse. 相似文献
5.
We examined the effects of process and observation errors on the selection of the stock–recruitment relationship (SRR) curve
using simulations. When the process and observation errors were added to both spawning stock biomass and recruitment, the
results were as follows: (1) When the proportional model was set as the true SRR model, there was a high probability that
the Ricker or Beverton and Holt model was selected in response to the errors; (2) When the Ricker or Beverton and Holt model
was set as the true SRR model, the proportional model was seldom selected in response to the errors; (3) The proportional
SRR model should be accepted as the optimum SRR model for the Pacific stock of Japanese sardine; (4) We should use an SRR
model that is constructed from more than two independent variables (spawning stock biomass, environmental factors, etc.) when
we discuss management of fisheries resources. 相似文献
6.
Leandro Santos Costa Felipe Guedes de Araújo Renan Rosa Paulino Luciano Jos Pereira Edgar Junio Damasceno Rodrigues Paula Adriane Perez Ribeiro Priscila Vieira Rosa 《Aquaculture Research》2019,50(9):2371-2379
Although daily variations in drug pharmacokinetics have been reported for a variety of teleost species, the influence of this daily variation on the cortisol response following anaesthesia remains poorly understood. To address this, two experiments were performed. The first experiment described the daily patterns of cortisol and glucose secretion in tilapia (Oreochromis niloticus). The second experiment investigated how the timing of anaesthetic administration (specifically at mid‐light [ML] or at mid‐dark [MD]) affects the induction and recovery times and plasma cortisol and glucose levels of juvenile Nile tilapia exposed to benzocaine, clove oil or tricaine methanesulphonate (MS‐222). The results revealed that the effect on the stress response associated with the moment when anaesthesia took place (ML or MD) varied according to the treatment (p < 0.05). Cortisol levels were significantly higher at ML for MS‐222 (ML = 116.23 ± 25.55; MD = 48.25 ± 22.33 ng/dl) (p < 0.05) and clove oil (ML 59.73 ± 14.27; MD 38.26 ± 12.07 ng/dl) (p < 0.05), whereas no significant differences were found between ML and MD cortisol levels for the control treatment (ML = 72.91 ± 18.42; MD = 64.80 ± 10.68 ng/dl) (p > 0.05) or in the benzocaine‐treated group (ML = 38.7 ± 4.90; MD = 38.60 ± 3.69 ng/dl) (p > 0.05). The highest plasma cortisol level in ML was found in the MS‐222‐treated group. All the tested anaesthetics had similar cortisol levels at MD (p > 0.05). 相似文献
7.
This study investigated the effects of estrogens on sexual differentiation in sea bass (Dicentrarchus labrax L.), a gonochoristic marine teleost that under culture conditions has a histologically sexual undifferentiated period that covers most of the first year of life, after which most individuals develop as males. Sea bass that had no noticeable histological sign of sex differentiation were fed estrogens at two doses (5 or 10 mg kg-1 food) and for different periods ranging from 48 to 426 days post fertilization (DPF). Exposure to the synthetic estrogen 17-ethynylestradiol (EE2) at 10 mg kg-1 food from 60 to 260 DPF, including the sensitive period to equivalent doses of synthetic androgens previously determined for this species (126-226 DPF), significantly (p < 0.05) more than doubled the number of juvenile females to 80%, compared to the control value of 33%, and completely suppressed gonadal development in the remaining 20% of the population. This suggests that the period during which sea bass gonads exhibit high sensitivity to androgens is also very sensitive to estrogens. A comparable exposure to the natural estrogen estradiol-17 (E2) resulted in 13% of the fish having suppressed gonadal development, but induced 57% of the fish to develop gonads with germinal tissue of both sexes, suggesting a pivotal role for E2 during this sensitive period. Earlier exposure to EE2 at 10 mg kg-1 food from 48-88 DPF, significantly (p < 0.05) increased the number of females to 62% from 36% in the control group, allowing for the normal testicular development in the remaining fish. In contrast, a later chronic exposure (226-426 DPF) to E2, at either 5 or 10 mg kg-1 food, starting when the gonads showed no sign of sexual differentiation but past the critical sensitive period, had no effect on the resulting overall sex ratios, indicating that after this period responsiveness of the gonads to estrogens decreases as gonadal sexual differentiation progresses. However, the consequences of this apparently innocuous exposure were later manifested in adults, exemplified by a significant dose-dependent reduction in the number of mature males at 626 DPF, coinciding with the second reproductive season, the time when males normally reach sexual maturation in cultured sea bass. This suggests that chronic exposure to E2 past the critical sensitive period may not affect the sex ratio, but could result in alterations in the male reproductive organs. This was later verified by histological analysis which revealed a significant (p < 0.05) dose-dependent reduction of the surface of the testicular lobules in the remaining males that did not mature. Together, these experiments illustrate both readily observable and subtle effects of estrogens on sex proportions, gonadal morphology and maturation rates, providing evidence that estrogen exposure can have delayed action in a teleost in a manner similar to the effects described for mammalian species. The possible existence of effects of this latter type in adult fish could be considered when evaluating the consequences of deliberate or accidental exposure to estrogens or putative estrogenic chemicals, particularly if such exposure had taken place during sex differentiation. 相似文献
8.
Y. Yoshiura Y.C. Sohn A. Munakata M. Kobayashi K. Aida 《Fish physiology and biochemistry》1999,21(3):201-210
A cDNA encoding the subunit of thyrotropin (TSH) was isolated from a goldfish (Carassius auratus) pituitary gland cDNA library. By comparing the sequence with other teleost TSHs, a signal peptide of 19 amino acids and a mature hormone of 131 amino acids were predicted for goldfish TSH subunits. The resulting putative mature hormone of 131 amino acids had well-conserved cysteine positions and a putative N-linked glycosylation site; homology was 51–67% with TSHs from other teleosts, 38–43% with tetrapod TSHs, but only 27 and 29% with goldfish GTH-I and -II, respectively. We also examined the effects of thyroid hormones (TH) and thiourea (TU, an inhibitor of TH production) treatments on TSH and GTH subunit gene expressions in the goldfish pituitary gland. After thyroxine (T4) treatment, circulating T4 concentration increased and TSH mRNA level decreased. Supressing the amount of circulating T4 and triiodothyronine (T3) by TU treatment increased the TSH mRNA level. Moreover, T4 replacement therapy (simultaneous treatment of both TU and T4) caused a high level of circulating T4 and a low level of circulating T3, and a decrease in the TSH mRNA level. Thus, changing levels of circulating TH exert a negative feedback on the level of TSH subunit mRNA in goldfish in vivo. On the other hand, GTH subunit mRNA levels were not affected by changes in the levels of circulating TH. 相似文献
9.
The distribution and movement between habitats with growth of the hard clam Meretrix lusoria were examined by comparing the size–frequency distributions among 17 sites in the Shirakawa–Midorikawa Estuary of the Ariake Sea. This clam is a commercially important bivalve in Japan, and its annual catch is largest in the Ariake Sea. At the study sites, new recruits were abundant at river mouths, and density was strongly affected by the distance from coastal tidal rivers and streams. In contrast, adults were widely distributed on tidal flats, although density was low at many sites. At marine site Oda, the density of adults was higher than that of new recruits at all sites and higher than that of juveniles at most sites. These results indicate that this species moves from riverine sites to marine sites with growth. Moreover, the observed low density of adult clams may indicate overfishing. The active movement of M. lusoria across the fishing grounds complicates the sustainable resource management of this species. Therefore, further studies are needed for effective resource management of M. lusoria. 相似文献
10.
H. Allan Bremner 《Journal Of Aquatic Food Product Technology》2013,22(1):16-19
Fillets from Pacific cod (Gadus macrocephalus) were salted with and without polyphosphates (PP) by means of a short three-step salting process. The changes in phosphate and water content during different steps of production were determined by comparing fillets with and without addition of PP. While fillet samples after salt injection and wet-salting contained different water content, from 80.1% to 74.6% depending on processing step and PP addition or not, after dry-salting there was no significant difference in water content between fillets with (58.1%) or without PP (58.9%). Dry-salted fillets with PP addition showed a phosphate content of 6.1 mg P2O5/g. In the following rehydration process (48 h), the total phosphate content dropped down to 2.9 mg P2O5/g, which was lower than the natural total phosphate content of 4.4 mg P2O5/g in the raw material. 相似文献
11.
Abstract. The Atlantic salmon, Salmo salar L., was once of major importance to the fishing industry along the River Rhine. This paper discusses the Dutch and German salmon catches over the years 1863–1950. Even up to the end of the last century, it was not uncommon for Dutch and German fishermen to land 100000 salmon a year. However, factors such as the increased use of locks and weirs along the Rhine, coupled with growth in pollution, soon led to a rapid decline in numbers. By 1933, the salmon fishing industry in the Netherlands had virtually ceased to exist. Analysis of the available catch statistics suggests that the decline in the salmon population could have started before official records began. Although the degree of scatter in the data and uncertainties in the assumptions preclude the possibility of drawing firm conclusions about the survival rate of salmon, these figures illustrate how difficult it will be to maintain a stable population in the Rhine. Moreover, a number of changes have taken place since the heyday of salmon in western Europe, which could compound the problem. Of particular importance in the context of the Rhine are:
- 1 the closure of two of the major migration routes to the sea (Haringvliet and Zuiderzee);
- 2 morphological changes in the river;
- 3 chemical and thermal pollution;
- 4 the loss of accessible spawning and nursery areas of the required quality;
- 5 the disappearance of salmon from other rivers that flow into the North Sea such as the Rivers Elbe, Weser and Ems. If salmon were only reintroduced into the Rhine, a certain proportion would probably stray and infiltrate these other rivers.
12.
13.
ABSTRACTThis study was aimed to investigate the effects of dietary β-carotene supplement for 42 days on lipid and protein oxidation biomarkers in carp meat at different times of storage. Seventy-five fish were divided into three groups: group 1 as control group was fed with basic diet; groups 2 and 3 received 50 and 100 mg kg?1 diet β-carotene, respectively. Based on the present study results, muscle malondialdehyde concentrations were significantly lower following β-carotene consumption at 0, 24, 72, and 96 h after harvest in group 3 compared to the control group (p < 0/05). Muscle protein carbonyl contents showed a significant decrease following β-carotene supplementation at 0, 48, and 96 h after harvest in group 3 compared to the control group. Ferric reducing antioxidant power values were significantly increased following β-carotene supplementation at 72 and 96 h after harvest in group 3 compared to the control group. The results indicated that β-carotene supplementation with a dose of 100 mg kg?1 diet is largely effective to improve the oxidative status of carp meat by reducing lipid and protein oxidation. 相似文献
14.
Hikaru Watanabe Makoto Okazaki Tsutomu Tamura Kenji Konishi Denzo Inagake Takeharu Bando Hiroshi Kiwada Tomio Miyashita 《Fisheries Science》2012,78(3):557-567
This study represents the first quantitative analysis of the characteristics of the distribution areas and stomach contents
of common minke whale Balaenoptera acutorostrata, sei whale B. borealis, and Bryde’s whale B. edeni in relation to oceanographic and prey environments in mid summer in the western North Pacific. Common minke whales were distributed
within subarctic regions and the northernmost region of the transitional domain, coinciding with the main habitat of their
preferred prey, Pacific saury Cololabis saira. Sei whales were mainly found in the northernmost part of the transition zone and showed prey preference for Japanese anchovy
Engraulis japonica, which was significantly more abundant in the main distribution area of the whale than in its adjacent areas. “Hot spots”
of Bryde’s whales were found in several regions of the transition zone between the subarctic boundary and the Kuroshio front.
This whale species preferred Japanese anchovy as prey, for which the distribution density was significantly higher in the
main distribution area of the whale than in the adjacent areas. These results indicate that the summer distributions of Pacific
saury and Japanese anchovy greatly influence the distributions of these whale species, suggesting that the whales’ habitat
selection is closely related to their prey selection. 相似文献
15.
The absorptions of 3,5,3-triiodo-L-thyronine (T3) and L-thyroxine (T4) from the intestinal lumen of the rainbow trout were compared in vivo. Tracer doses of [125I]T4 (+T4) or [125I]T3 (*T3) were injected through an anal cannula into the duodenum of trout fasted for 3 days at 12°C, and radioactivity was measured in blood and tissues at 4–48 h. *T3 was removed more extensively than *T4 from the intestinal lumen and more radioactivity was absorbed into the blood and tissues of u+T3-injected trout than *T4-injected trout. HPLC analysis showed that a high proportion of the radioactivity in the plasma, liver, kidney and intestinal lumen of *T3-injected trout remained as the parent *T3. However, in *T4-injected trout most plasma radioactivity was in the form of 125I–, and by 24 h a high proportion of luminal radioactivity was 125I–. By 48 h, over 4% of the injected *T3 and 1% of the injected *T4 dose resided in the gall bladder, primarily as derivatives of *T3 or *T4. We conclude that T3 is absorbed more effectively than T4 from the intestinal lumen of fasted trout, indicating the potential for an enterohepatic T3 cycle. 相似文献
16.
This study examined the production and welfare effects of including a large self‐feeder competent rainbow trout, Oncorhynchus mykiss (Walbaum) (~665 g) in groups of smaller self‐feeder competent conspecifics (~234 g). Costs and benefits were examined for both welfare (aggression, fin damage, condition and mortality) and production (self‐feeder utilization and growth). The 8‐week experiment used six groups of small trout; three treatment groups containing a large trout and three control groups. After 4 weeks the large fish were removed from treatment groups and added to control groups, thus reversing the treatments. Whilst it was thought that the presence of a larger fish would suppress aggression in smaller conspecifics this did not occur. In fact aggression was significantly (P = 0.036) higher when large trout were present during the first 4 weeks. No significant differences were found between other welfare indicators, self‐feeder utilization or production parameters. From a production and welfare perspective these results suggest that with the exception of initially increasing aggression larger fish do not represent a significant benefit or risk to smaller conspecifics being cultured in self‐feeder equipped tanks, when all fish are self‐feeder competent. 相似文献
17.
18.
In order to understand the processes affecting early survival of the Japanese anchovy Engraulis japonicus population in the Seto Inland Sea, we examined the monthly fluctuations in the abundance and survival rates from eggs to recruits (15-day-old larvae, 13?mm in standard length fish, defined as 1-month-old fish) during their main spawning season from 1980 to 2007. The abundance of the yolksac larvae positively correlated with the abundance of eggs, but the abundance of recruits did not significantly correlate with the abundance of yolksac larvae. These results imply that the survival rate during the egg stage is relatively stable, but that the rate during the larval stage is variable. Of the three most recent decades (1980s, 1990s and 2000s), the abundance of recruits was highest in the 1980s. The decrease in the abundance of recruits after the 1990s can be considered to have occurred through a decline in survival rate during the larval stage because there were no significant differences in egg abundance, yolksac larval abundance, and survival rates during the egg stage in the three decades of the study period. 相似文献
19.
Elham Payandan Mahshid Shamloofar Hadi Koohsari 《Journal Of Aquatic Food Product Technology》2017,26(5):593-603
This study has evaluated the effects of different concentrations of the water and ethanolic extracts of Iranian propolis (WEP and EEP) on the microbiological and sensory parameters of minced common carp meat that was stored at 4°C for 9 days. The chemical compounds of the extracts were identified by gas chromatography–mass spectroscopy (GC-MS) analysis. The results revealed that WEP and EEP extracts were efficient against the spoilage microorganisms, including total plate counts (TPCs), psychrotrophic populations (PTCs), lactic acid bacteria (LAB), and even Staphylococcus aureus. There was a significant difference in the bacteria growth between samples treated with WEP or EEP and the control sample during storage. Inhibitory effects were, respectively, 7% EEP > 5% EEP > 3% EEP > 7% WEP > 5% WEP > 3% WEP. In all treatments, PTC counts were higher than 7 log CFU/g after 6 days as well as TPC, LAB, and S. aureus populations after 9 days. Overall, the results show that EEP and WEP have good antimicrobial activity due to high phenolic and flavonoid compounds, including caffeic acid, tectochrysin, aceacetin, chrysin, pinostrobin, pinobanksin-3-acetate, galangin-3-methyl ester, and pinocembrin chalcone. Sensory evaluation shows very slight improvement in sensory properties (color, odor, texture, and overall acceptability) of the treated samples with the different extracts of Iranian propolis. 相似文献