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1. Development of environmental protected areas has been driven ‘more by opportunity than design, scenery rather than science’ (Hackman A. 1993. Preface. A protected areas gap analysis methodology: planning for the conservation of biodiversity. World Wildlife Fund Canada Discussion Paper; i–ii). If marine environments are to be protected from the adverse effects of human activities, then identification of types of marine habitats and delineation of their boundaries in a consistent classification is required. Without such a classification system, the extent and significance of representative or distinctive habitats cannot be recognized. Such recognition is a fundamental prerequisite to the determination of location and size of marine areas to be protected. 2. A hierarchical classification has been developed based on enduring/recurrent geophysical (oceanographic and physiographic) features of the marine environment, which identifies habitat types that reflect changes in biological composition. Important oceanographic features include temperature, stratification and exposure; physiographic features include bottom relief and substrate type. 3. Classifications based only on biological data are generally prohibited at larger scales, due to lack of information. Therefore, we are generally obliged to classify habitat types as surrogates for community types. The data necessary for this classification are available from mapped sources and from remote sensing. It is believed they can be used to identify representative and distinctive marine habitats supporting different communities, and will provide an ecological framework for marine conservation planning at the national level. Copyright © 2000 John Wiley & Sons, Ltd. 相似文献
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Norway lobster Nephrops norvegicus fisheries are often characterized by high bycatch and discard rates. However, fisheries species exhibit differences in vertical behaviour that can be used to develop selective devices. We developed a separator frame that can be inserted into the forward part of a cod-end to divide it into a bottom cod-end and a top cod-end. In the top cod-end we inserted a 3-m-long window constructed of 274-mm mesh. The separator frame was tested from a commercial vessel in the Kattegat and Skagerrak area. Small mesh net bags were used to collect the catch going through the separator frame and ending up in the bottom cod-end, the top cod-end, or penetrating the window. The majority of Norway lobster and flatfish entered the bottom cod-end, and most gadoids entered the top cod-end. A relatively high proportion of gadoids and flatfish that entered the top cod-end penetrated the window. The separation was size dependant for some of the investigated species. 相似文献
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Mrityunjoy Kunda M Ekram Azim M Abdul Wahab Somen Dewan M Abdul Majid & Shakuntala H Thilsted 《Aquaculture Research》2009,40(9):1089-1098
An on-farm trial was carried out from February to June 2006 to evaluate the growth and production performance of catla ( Catla catla ) and tilapia ( Oreochromis niloticus ) with freshwater prawn ( Macrobrachium rosenbergii ) and mola ( Amblypharyngodon mola ) in farmer's rice fields. In all treatments, 20 000 mola ha−1 and 20 000 prawn ha−1 were stocked. Besides, stocking included 2500 catla ha−1 in treatment-I, 2500 tilapia ha−1 in treatment-II and catla and tilapia at 1250 ha−1 each in treatment-III . Prawns were fed in the evening with pellets at a feeding rate of 3–8% body weight (initially 8% and gradually decreased to 3%). Catla and tilapia were fed in the morning with a paste of mustard oil cake and rice bran at a feeding rate of 3% body weight. Significantly higher combined production of fish and prawn observed was 2142 kg ha−1 in treatment-I. The benefit:cost ratio was found to be significantly higher in treatment-I than in treatment-II and there were no differences between treatments I and III. From the production and economic point of view, treatment-I was found to be the best proposition for the rotational rice–fish culture systems. 相似文献
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ABSTRACT: The relation between the density of fish and parameters such as body weight, condition factor and the hepatic triglyceride (TG) content of masu salmon Oncorhynchus masou juveniles after release into a natural stream were studied. Hatchery-reared juveniles of different sizes and numbers were released in May 1999, 2000 and 2001, and investigations were carried out from July to September each year. The density of fish was relatively high in 1999, when juveniles of the largest size and number were released, but then continued to decrease during the investigation. The hepatic TG content remained considerably low in 1999, and there was a significant negative correlation between the density of fish and the hepatic TG content of the juveniles caught over three years. The initial fish size and number at release as well as the nutritional condition of the juveniles may affect the density of fish after release. 相似文献
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ABSTRACT: The present study reports the annual variation in consumption of the sea urchin Strongylocentrotus intermedius by avian predators on a rocky shore where the culture of sea urchins has been conducted. Carrion crow and a few gull species were the most abundant avian predators and consumed a large number of sea urchins. Crows consumed mostly natural sea urchins, approximately 36 kg ww/ha per year on the intertidal rocky bench, but the gull species consumed mostly cultured sea urchins, approximately 100 kg ww/ha per year in the culture area. The seasonal variation in the amount of sea urchins consumed by crows was higher than that by the gull species, presumably because of the difference in foraging behavior in association with the seasonal tidal cycle. The natural sea urchins consumed are an allochthonous input from the subtidal to the intertidal habitat, and thus, crow predation may not affect the natural and the cultured populations of the sea urchin. The gull species consumed much of the cultured sea urchin, and thus, may be regarded as an effective predator causing damage to sea urchin culture. The results suggest that further studies are needed to determine why the gull species selectively feed on cultured sea urchins. 相似文献
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A meta‐analysis of available data on dose response to dietary phosphorus (P) in fish from over 70 feeding trials reported in 64 published studies covering over 40 species of fish was performed. Broken‐line regression was used to model the data sets. The meta‐analysis showed that estimated minimal dietary P level varies with the response criterion and that estimates should preferably be expressed in terms of available P than in terms of total P. Estimates based on whole‐body P concentration (4.7 g available P kg?1 dry matter, DM) or vertebral P (5.2 g available P kg?1 DM) were greater than that for maximizing somatic weight gain (WG) (3.5 g available P kg?1 DM) or plasma P concentration (2.8 g available P kg?1 DM). P content of fish varies linearly with body mass (3.6 g kg?1 live weight). Use of ingredients rich in P or of diets with high basal P content or high levels of water P concentration can affect the estimations. Among the different response criteria tested, WG was found to be the most reliable and whole‐body P concentration to be the most stringent criterion to estimate P requirement of a given fish species. Expressing available P requirement as g P per unit DM or digestible energy (DE) in the diet was equally effective, but expressing in terms of g P intake per kg BW0.8 per day would be more precise. 相似文献
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Catherine Elizabeth Gibson David Williams Rebecca Dunlop Suzanne Beck 《水产资源保护:海洋与淡水生态系统》2020,30(8):1702-1710
- Bottlenose dolphins encountered around the Irish coast are considered part of a wide‐ranging coastal community; however, knowledge on the significance of the north of Ireland for this species is limited by a lack of dedicated effort.
- Through social media, the opportunity now exists to gather large volumes of citizen science data in the form of high‐quality images, potentially extending the spatial and temporal scope of photo‐identification studies.
- The purpose of this study was to investigate social media as a data resource for photo‐identification studies and to provide a preliminary assessment of bottlenose dolphins in the north of Ireland. Specifically, the study sought to examine the photo‐identification data for spatial clustering.
- The study identified 54 well‐marked individuals and provided evidence of potential year‐round occurrence, with successful re‐sightings throughout the study period (2007–2016). There was a geographic concentration of re‐sightings along the north of Ireland, suggestive of interannual site fidelity. These results provide scientific rationale for strategically targeting the north of Ireland in future research on the Irish coastal community.
- For effective conservation of the bottlenose dolphin it is imperative that scientific research, and resultant management objectives, consider wide‐ranging communities such as the Irish coastal community. Our research highlights data collection via social media as a cost‐effective and scientifically valuable tool in the photo‐identification of coastal cetaceans. We recommend that this method is used in research on low‐density and wide‐ranging coastal cetaceans.
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Melanin deposits in white muscle represent a potentially serious quality problem for farmed cod. Black lines of deposited
melanin are associated with blood vessels and consist of layers of melanin-filled cells. Despite numerous anecdotal reports
of melanosis in farmed cod no detailed investigations into the underlying mechanisms have been undertaken. In this study we
have confirmed that melanosis is present in both farmed and wild cod. However, the incidence of melanosis in wild fish is
much lower than that in farmed fish. In addition, we have demonstrated that tyrosinase, a copper-dependent metalloenzyme that
is the primary enzyme of melanin synthesis, is present in cod tissues. Copper levels are significantly different in the white
muscle of farmed (0.5 ± 0.03 mg/kg wet weight) and wild (0.34 ± 0.01 mg/kg wet weight) cod (P < 0.05) and in the blood vessels of farmed (2.23 ± 0.37 mg/kg wet weight) and wild (0.32 ± 0.02 mg/kg wet weight) cod (P < 0.05). Similarly, differences in the levels of tyrosinase activity were observed in both muscle and blood vessels. Melanised
tissues contain higher copper concentrations than tissue containing little or no melanin. Furthermore, we have shown that
the addition of copper to protein extracts from fish muscle causes an increase in tyrosinase activity in vitro. Our results
suggest that overabundance of copper in commercial feeds leads to increased melanin synthesis via increased tyrosinase activity.
We propose that melanin is deposited at sites of high copper exposure and subsequently sequesters copper as a means of reducing
the overload stress on other homeostatic mechanisms. 相似文献
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ABSTRACT: A new protein named MSP-SC (matrix shell protein from scallop) with a molecular weight of 14 kDa was isolated from the shell of a scallop, Patinopecten yessoensis , using gel filtration column chromatography, ion exchange column chromatography, and reverse phase C4 column chromatography. A comparison of the known protein sequences with the N-terminal sequence of MSP-SC showed that the protein sequence of MSP-SC was novel. Immunohistochemistry using a polyclonal antibody against MSP-SC showed that MSP-SC is expressed in the mantle pallial cell layer but not in the muscle tissue, and showed a punctate distribution along the horizontal calcified layer in the shell. The isolated MSP-SC inhibited the formation of calcium carbonate (CaCO3 ) crystals in a dose-dependent manner. The CaCO3 crystals grown in the presence of a lower concentration of MSP-SC were much larger and aggregated when compared with those formed in the absence of MSP-SC. In addition, the crystal had a radial and not cubical morphology. These results suggest that MSP-SC regulates the formation and the morphology of CaCO3 crystals in the shell. Moreover, its ability to aggregate CaCO3 crystals and its localization along the horizontal calcified layer in the shell suggest that MSP-SC may serve to connect the CaCO3 layers in the scallop shell. 相似文献
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Using a well‐being approach to develop a framework for an integrated socio‐economic evaluation of professional fishing 
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下载免费PDF全文 The principles of Ecologically Sustainable Development and Ecosystem Based Fisheries Management require that fisheries be managed for social as well as environmental and economic objectives. Comprehensive assessments of the success of fisheries in achieving all three objectives are, however, rare. There are three main barriers to achieving integrated assessments of fisheries. Firstly, disciplinary divides can be considered “too hard” to bridge with inherent conflicts between the predominately empirical and deductive traditions of economics and biophysical sciences and the inductive and interpretative approach of much of the social sciences. Secondly, understanding of the social pillar of sustainability is less well developed. And finally, in‐depth analysis of the social aspects of sustainability often involves qualitative analysis and there are practical difficulties in integrating this with largely quantitative economic and ecological assessments. This article explores the social well‐being approach as a framework for an integrated evaluation of the social and economic benefits that communities in New South Wales, Australia, receive from professional fish harvesting. Using a review of existing literature and qualitative interviews with more than 160 people associated with the fishing industry the project was able to identify seven key domains of community well‐being to which the industry contributes. Identification of these domains provided a framework through which industry contributions could be further explored, through quantitative surveys and economic analysis. This framework enabled successful integration of social and economic, and both qualitative and quantitative information in a manner that enabled a comprehensive assessment of the value of the fishery. 相似文献
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Abstract Loss of river-floodplain (lateral) connectivity has impacted on fish communities and fisheries around the world. However, evidence of the impacts of reduced lateral connectivity on Australian native fish remains scant. To document these impacts, isolated pools located immediately downstream of two major regulators (or weirs) that control flows from the Murray River to an extensive off-stream floodplain, were pumped out five times between 2001 and 2006. A total of 20 980 fish (16 228 native, 4752 non-native) comprising 15 species (five non-native) were collected. Five fish species collected are classified as threatened, while turtles and macroinvertebrates were also present. Regulator operation appeared to affect the number of fish becoming stranded, with the highest number coinciding with longer regulator openings and extended floodplain inundation. Hundreds of floodplain regulators exist on Australian rivers, and all have the potential to impact upon native fish. Trial of several potential management and engineering solutions is recommended to improve river–floodplain connectivity in lowland rivers. 相似文献
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Chuntao Yuan Dongmei Li Wei Chen Fangfang Sun Guanghong Wu Yi Gong Jianqing Tang Meifang Shen Xiaodong Han 《Fish physiology and biochemistry》2007,33(2):93-101
The herbal immunoregulation mixture (HIRM) were extracts of several traditional Chinese medicines (TCMs): Astragalus membranaceus (from the root and stem), Polygonum multiflorum Thunb. (from the root), Isatis tinctoria L. (from the root), Glycyrrhiza glabra (from the stem). Immune parameters, which included macrophage phagocytic activity, macrophage reactive oxygen species (ROS),
activity of serum lysozyme, nitric oxide synthetase (NOS) and superoxide dismutase (SOD), levels of total serum protein, globulin,
albumin, triglyceride and cholesterol, were determined in carp that had been fed diets containing HIRM at 0.5% or 1% for 30 days.
The results showed that, compared with those in the control group, the diets with 0.5% and 1% HIRM resulted in significant
increase in macrophage phagocytic activity, macrophage ROS and the levels of total protein, globulin, albumin and NOS activity
in serum (P < 0.05), and no significant difference was found in SOD, lysozyme activities and triglyceride level (P > 0.05). On the other hand, 0.5% HIRM led to evident enhancement of NOS activity and cholesterol level compared to 1% HIRM.
These results indicated that HIRM might elevate the function of immunity in carp (Cyprinus carpio). 相似文献
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Todd David Sink Sathyanand Kumaran Rebecca T. Lochmann 《Fish physiology and biochemistry》2007,33(3):189-193
Baitfish such as golden shiners are subjected to stress during harvesting, grading, and transport. Their small size makes
it difficult to measure the stress response with the biological indicator cortisol using conventional assay methods for plasma.
This paper examines the development and validation of methods for whole-body cortisol extraction from individual baitfish.
Three types of extracts were tested: (1) an ethyl ether unaltered extract (UA); (2) an extract reconstituted in phosphate
buffered saline (PBS); (3) an extract that had been increased in volume by the addition of food-grade vegetable oil (VO).
These extracts were evaluated using validation tests with radioimmunoassays (RIA) and enzyme-linked immunosorbent assays (ELISA).
The UA extract produced inadequate volumes of extract for multiple assays and could not be used for the determination of cortisol
in a single fish. The PBS reconstitution method failed the precision recovery of serial dilutions (62.3%), linearity (R
2: 0.7864), and parallelism validation tests. The VO volume-boosting method passed all validation tests [intra-assay coefficent
of variation (%CV): 16.3 for ELISA and 5.9 for RIA; inter-assay %CV: 10.3; spiked recovery: 102.0%; dilution recovery: 93.0%;
linearity R
2: 0.9435; log of serial dilutions was parallel] and provided enough extract for multiple assays from an individual baitfish.
Based on these results, we conclude that the VO volume-boosting method presents a means for determining cortisol from individual
baitfish using either RIA or ELISA assays. 相似文献
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H. Qi X. P. Dong L. N. Cong Y. Gao L. Liu T. Mikiro B. W. Zhu 《Fish physiology and biochemistry》2007,33(2):181-188
The sea cucumber (Stichopus japonicus) is able to undergo autolysis in response to a variety of environmental and mechanical cues. Within the framework of a long-term
study of this phenomenon we have purified a protease from the body wall of the sea cucumber by means of ion-exchange chromatography
with DE-52 cellulose and gel filtration chromatography with Sephadex G-100. The final enzyme preparation was nearly homogeneous
on polyacrylamide gel electrophoresis, and its molecular weight was estimated to be approximately 35.5 kDa. The purified enzyme
exhibited a maximum activity for the hydrolysis of casein at pH 7.0 and 50°C and a remarkable stability at pH 4.0–7.0 and
40–60°C. Based on the inhibition and activation profiles obtained with numerous specific protease inhibitors and an activator,
the protease purified from the body wall of the sea cucumber was defined to be a cysteine-like protease. 相似文献
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Survival and behaviour of Atlantic salmon smolts passing a run‐of‐river hydropower facility with a movable bulb turbine 下载免费PDF全文
下载免费PDF全文 E. B. Thorstad T. B. Havn S. A. Sæther L. Heermann M. A. K. Teichert O. H. Diserud M. Tambets J. Borcherding F. Økland 《Fisheries Management and Ecology》2017,24(3):199-207
Downstream migration of radio‐tagged Atlantic salmon smolts, Salmo salar L., was studied in the Kinzig, Germany, to examine effects of passing a run‐of‐river hydropower station with a movable bulb turbine. Immediate mortality for smolts passing the power station was low (3%–6%), probably facilitated by a curved rack in front of the turbine and the possibility to pass over it. Mortality in the impounded stretch above the power station was also low (1.5% extra mortality compared to a control stretch). The combined mortality due to hydropower was 5%–8%, excluding delayed effects. Most smolts followed the main flow passing through the turbine area (94%). Only few used a fishway (4%) or a nearby millstream (2%). Migration speed was slowed down at the power station, but the passage only caused a short delay (average/median 8.6/1.3 hr). However, even low mortality and short delays at several power stations and reservoirs may have considerable cumulative effects. 相似文献
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A. D. Jamieson 《Aquaculture Research》1979,10(2):63-72
The sport-fishery for the Atlantic salmon Salmo salar L. has been developed in Scotland for a considerable period of time yet for various reasons there are very few details published on those aspects of the sport which are of interest to a student of any natural or recreational resource. There is a need for information on such aspects as the ownership and boundaries of the fisheries, their qualities, their capacities and their availability. This information can best be presented in map form and this paper illustrates those parameters with information which was available for the salmon fisheries of the River Conon and the River Blackwater in Ross-shire, which are owned by the North of Scotland Hydro-Electric Board. This sort of information would be an essential task of any reorganized salmon fisheries administration, such as the Area Boards originally proposed by the Hunter Report of 1965. 相似文献