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1.
《Marine Policy》2017
This study estimates consumer demand for eco-friendly labeled canned tuna products in two distinct US marketing channels, conventional and natural supermarkets, to evaluate market-based incentives for conservation measures that affect fishing costs and retail prices. Using retail scanner data, this paper finds that US consumer demand for canned tuna varies depending on the species of tuna, what gear type was used, whether the can is sold in natural food or conventional supermarkets, and whether canned product is or is not certified as eco-friendly. The paper's main conclusions are that retail price premiums for eco-friendly products face upper limits due to consumer responses to higher prices, and are most effective when coupled with: (1) inelastic own-price elasticity of demand; (2) price premium signals that are transmitted from retail markets to raw material producers; and (3) limited retail consumption substitution possibilities with lower-priced conventional products that help maintain price premiums and that otherwise create conservation disincentives by increasing conventional supply. Results from this paper not only have unique implications for various forms of international tuna fisheries policy that incorporates or anticipates change in market behavior, but also could serve as a scientific reference to clarify the trade disputes. 相似文献
2.
Large-scale use of oil-based muds for drilling operations offshore can lead to high concentrations of aromatic hydrocarbons in the sediments close to these platforms. Fish were trawled from stations close to and distant from such platforms and the levels of hepatic aryl hydrocarbon hydroxylase (AHH) were determined in cod, haddock and whiting. These three species were caught in sufficient numbers to make reasonable preliminary data sets. The data for cod and haddock showed significantly higher levels of AHH in the livers of fish caught close to oil platforms than in those caught in areas away from oil activity, while whiting showed no such differences. A much larger sample number together with some measurement of enhanced cytochrome P-450 levels would be required to substantiate this trend, but these data are the first indications that the oil in the sediments around platforms may be biochemically available to fish in the area. 相似文献
3.
《Journal of Sea Research》2004,51(3-4):313-328
Fishing effort has strongly increased in the North Sea since the mid-19th century, causing a substantial reduction in the population size of exploited fish stocks. As fisheries research has developed simultaneously with the industrialisation of the fisheries, our knowledge of population dynamics at low levels of exploitations is limited. Otoliths retrieved from archaeological excavations offer a unique opportunity to study growth rates in the past. This study compares historical and present-day growth rates for four commercially important demersal fish species. A total of 2532 modern otoliths (AD 1984–1999) and 1286 historical otoliths (AD 1200–1925) obtained from archaeological excavations in Belgium and Scotland were analysed. Comparison of the growth patterns between eras revealed a major increase in growth rate of haddock, whereas growth changes were not observed in saithe and only in the smaller size classes of plaice and cod. Comparison of our results with literature data indicates that the observed growth rate changes in plaice and cod occurred within the 20th century. Apparently the onset of industrialised fisheries has not greatly affected the growth of plaice, cod and saithe populations in the North Sea. This result contradicts the expectation of density-dependent limitation of growth during the era of pre-industrialised fishing, but is in agreement with the concentration hypothesis of Beverton (Neth. J. Sea Res. 34 (1995) 1) stating that species which concentrate spatially into nursery grounds during their early life-history may ‘saturate’ the carrying capacity of the juvenile habitat even though the adult part of the population is not limited by the adult habitat. 相似文献
4.
The regime shift of the 1920s and 1930s in the North Atlantic 总被引：6，自引：3，他引：6
During the 1920s and 1930s, there was a dramatic warming of the northern North Atlantic Ocean. Warmer-than-normal sea temperatures, reduced sea ice conditions and enhanced Atlantic inflow in northern regions continued through to the 1950s and 1960s, with the timing of the decline to colder temperatures varying with location. Ecosystem changes associated with the warm period included a general northward movement of fish. Boreal species of fish such as cod, haddock and herring expanded farther north while colder-water species such as capelin and polar cod retreated northward. The maximum recorded movement involved cod, which spread approximately 1200 km northward along West Greenland. Migration patterns of “warmer water” species also changed with earlier arrivals and later departures. New spawning sites were observed farther north for several species or stocks while for others the relative contribution from northern spawning sites increased. Some southern species of fish that were unknown in northern areas prior to the warming event became occasional, and in some cases, frequent visitors. Higher recruitment and growth led to increased biomass of important commercial species such as cod and herring in many regions of the northern North Atlantic. Benthos associated with Atlantic waters spread northward off Western Svalbard and eastward into the eastern Barents Sea. Based on increased phytoplankton and zooplankton production in several areas, it is argued that bottom-up processes were the primary cause of these changes. The warming in the 1920s and 1930s is considered to constitute the most significant regime shift experienced in the North Atlantic in the 20th century. 相似文献
5.
《Marine Policy》2017
Eco-labeling is a market-driven mechanism to promote sustainable fisheries. The most widely used certification scheme for seafood eco-labeling is issued by the Marine Stewardship Council (MSC), but the MSC has been criticized for favoring large-scale industrial fisheries. The benefits from eco-labeling can potentially be significant, ranging from price premiums to enriched understanding of fisheries management among fishers; however, anecdotal evidence from MSC-certified fisheries across various countries highlights the struggle of many small-scale fisheries to meet the costs of certification. The lack of environmental awareness in domestic markets can impede the spread of MSC eco-labeling among small-scale fisheries. In the absence of consumer preferences for seafood sustainability, and without subsidies, the certification may not be an appropriate tool for small-scale seafood producers. Examination of the case of an MSC-certified small-scale fishery suggests some efforts to achieve economies of scale; multi-species fisheries can apply for MSC certification as a single unit of assessment, and fisheries can cooperate with neighboring fisheries that target the same fish stock to share assessment costs. In a market where no price premium has been generated, effective face-to-face marketing is pivotal. The MSC will need to be committed to pursuing price premiums in new markets if it is to extend its reach further to small-scale fisheries. 相似文献
6.
《Marine Policy》2017
Cod and haddock are two of the “big 5” UK supermarket fish species and intrinsic to fish and chip shops nationwide. UK whitefish fleets produce a significant amount, however there is a reliance on imports to maintain supply. The UK is in a strong position to compete for raw material from Iceland and Norway given high prices paid for imports and investment by Icelandic and Norwegian companies in the UK. Regarding UK production of whitefish, the European Common Fisheries Policy landing obligation has introduced significant uncertainty. To avoid discarding of any quota stock, fishing may be stopped before all target stocks quota is reached. For demersal fleets, there is a transition period between 2016 and 18 where target stocks are introduced according to Advisory Council and EU agreement and Article 15, with all quota stocks from 2019. As the capacity of the fleets balance to the new regulations, supply will likely return and if maximum sustainable yield (MSY) is reached in 2020 then an increase in TACs from current levels is likely too. However, markets and industries can change in a short period. Particularly, most processing companies are small to medium size enterprises and those that concentrate on cod and haddock may have to adjust their business. Fleets could be resilient to such short term reductions in landings however this cannot be assumed. The competitiveness of producers will surely be affected in the short to medium term as a result. 相似文献
7.
Harald Loeng Ken Drinkwater 《Deep Sea Research Part II: Topical Studies in Oceanography》2007,54(23-26):2478
The principal features of the marine ecosystems in the Barents and Norwegian Seas and some of their responses to climate variations are described. The physical oceanography is dominated by the influx of warm, high-salinity Atlantic Waters from the south and cold, low-salinity waters from the Arctic. Seasonal ice forms in the Barents Sea with maximum coverage typically in March–April. The total mean annual primary production rates are similar in the Barents and Norwegian Seas (80–90 g C m−2), although in the Barents, the production is higher in the Atlantic than in the ice covered Arctic Waters. The zooplankton is dominated by Calanus species, C. finmarchicus in the Atlantic Waters of the Norwegian and Barents Seas, and C. glacialis in the Arctic Waters of the Barents Sea. The fish species in the Norwegian Sea are mostly pelagics such as herring (Clupea harengus) and blue whiting (Micromesistius poutassou), while in the Barents Sea there are both pelagics (capelin (Mallotus villosus Müller), herring, and polar cod (Boreogadus saida Lepechin)) and demersals (cod (Gadus morhua L.) and haddock (Melanogrammus aeglefinus)). The latter two species spawn in the Norwegian Sea along the slope edge (haddock) or along the coast (cod) and drift into the Barents Sea. Marine mammals and seabirds, although comprising only a relatively small percentage of the biomass and production in the region, play an important role as consumers of zooplankton and small fish. While top-down control by predators certainly is significant within the two regions, there is also ample evidence of bottom-up control. Climate variability influences the distribution of several fish species, such as cod, herring and blue whiting, with northward shifts during extended warm periods and southward movements during cool periods. Climate-driven increases in primary and secondary production also lead to increased fish production through higher abundance and improved growth rates. 相似文献
8.
Malcolm L. Spaulding Mark Reed Eric Anderson Tatsusaburo Isaji J.Craig Swanson Saul B. Saila Ernesto Lorda Henry Walker 《Estuarine, Coastal and Shelf Science》1985,20(1):41-53
An oil spill fishery impact assessment model system has been applied to the Georges Bank-Gulf of Maine region to assess the sensitivity of probable impact on several key fisheries to spill location and timing. Simulations of the impact on the fishery of tanker spills (20 million gallons released over 5 days), at two separate locations for each season of the year, and blowout spills (68 million gallons released over 30 days) at one location, with monthly releases and at six other locations with seasonal spills have been studied. Atlantic cod has been employed as the principal fish species throughout the simulations. Impacts on Atlantic herring and haddock have also been investigated for selected cases. All spill sites are located on Georges Bank with the majority in the general region of OCS leasing activity.The results of these simulations suggest a complex interaction among spill location and timing, the spatial and temporal distribution of spawning, the population dynamics of the species under study, and the hydrodynamics of the area. For the species studied, spills occurring during the winter and spring have the largest impact with cod being the most heavily impacted followed by haddock and herring. In all cases, the maximum cumulative loss to the fishery of a one time spill event never exceeded 25% of the annual catch with the exact value depending on the number of ichthyoplankton impacted by the spill and the compensatory dynamics of the population. 相似文献
9.
《African Journal of Marine Science》2013,35(2):243-252
Management measures for South African line-caught fish include output controls such as closed seasons, bag and size limits and no-take moratoria. The main condition for these measures to be effective is that undesirable catches can be successfully released. However, most of the line-caught fish species are susceptible to barotrauma, a condition caused in physoclists by the rapid reduction of hydrostatic pressure during the ascent to the surface during capture. We investigated the effects of barotrauma on five commercially important species: roman Chrysoblephus laticeps, silver kob Argyrosomus inodorus, hottentot Pachymetopon blochii, santer Cheimerius nufar and carpenter Argyrozona argyrozona. A classification of the external signs of barotrauma was developed and internal and external signs of barotrauma were examined in relation to fishing depth and fish size, and compared between species. Immediate post-release mortality was investigated during a catch-and-release experiment. Medium-term survival of C. laticeps (~1 d) was examined by returning fish to depth in cages and subsequent monitoring on SCUBA. Our results indicate that most of the fish experience barotrauma even when caught at relatively shallow depths. External signs include extension of the inflated, everted stomach through the mouth, distended eyes, protrusion of the hind-gut and other organs through the cloaca, and gas bubbles in the dermal tissue between the fin rays. The absence of any obvious external signs of barotrauma can be misleading as dissections of such fish revealed ruptures of the swimbladder and other internal injuries consistent with barotrauma. Our results indicate that there might be significant post-release mortality, a factor that needs to be taken into account during stock assessment predictions and during the implementation of catch restrictions. 相似文献
10.
Recently, how different attributes influence the price of fish has received increased attention. This is partly due to the perceived impact of different attributes on quality and price, but lately environmental concerns are also playing a part. In contrast to earlier studies that focus on the Ex-Vessel or retail level, this study investigates wholesale data, for hake in Spain. The wholesale data provide information on a wide range of origins as the hake market has increasingly become global. The empirical analysis is conducted by estimating a hedonic price function. The results indicate that while fishing gear and size are important attributes, the origin of the fish is in this case the clearly most important attribute in determining the price. The price more than doubles for fish from the most preferred source, Catalonia, relatively to the fish from the least preferred source, Namibia. 相似文献
11.
《Journal of Sea Research》2007,57(4):329-337
Increasing Scandinavian harbour seal populations during the last decades coincide in time with the collapse of the cod fishery. Assumptions of a causal relationship have led to claims favouring re-introduction of seal hunting. Proposals for ‘adaptive management’ often assume that decimating seal populations will automatically favour the fishery. This argument presupposes seal predation to be sufficiently large to have a measurable impact on the fish population. The potential magnitude of the cod-seal interaction was analysed using data on harbour seal abundance, feeding habits and compiled information on cod life history and cod landing statistics. A size-structured life history matrix for the cod population was applied and the size-specific prey preferences of harbour seals were taken into account. Estimated seal predation was small compared to both the landings by the fishery, and to minimum estimates of the total cod population. Furthermore, since the size classes of cod targeted by seals have low reproductive values, the impact of seal predation on cod production will be further reduced. Our analyses suggest harbour seals have a negligible impact on the cod fishery. 相似文献
12.
The first use of Fulton's K for assessing and comparing the conditions of inter‐tidal fish populations 
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下载免费PDF全文 Fulton's K condition factor was applied, for the first time, to inter‐tidal specimens of the shanny (Lipophrys pholis) and long‐spined scorpion fish (Taurulus bubalis) from two English rocky shore and two Welsh rocky shore sites during summer 2010 and winter 2011. As both species contribute to the diet of commercial species such as cod (Gadus morhua) and near‐threatened species such as the European otter (Lutra lutra), their condition may affect that of these predators. Fulton's K found that inter‐tidal Welsh fish maintained a ‘good’ condition between seasons, whereas the inter‐tidal English fish were in a poorer condition during winter. Although condition also changed amongst the sites on each coast, further studies are needed into fish morphologies, environmental parameters, prey availabilities and abundances, and fish specimen sex and maturities. 相似文献
13.
Scott AP Katsiadaki I Witthames PR Hylland K Davies IM McIntosh AD Thain J 《Marine environmental research》2006,61(2):149-170
An ELISA for cod vitellogenin (VTG) has been set up using cod lipovitellin for plate coating and standardisation. The assay has been applied to plasma samples collected from male and female cod caught in three distinct areas around the UK, three areas off the Norwegian coast and also to cod reared initially at an aquaculture site and subsequently maintained at a research station. The aim of the study was to determine whether there were any signs of oestrogenic endocrine disruption in a fish species living offshore. VTG induction was found in male cod caught in the North Sea, the Shetland Box area, in Oslofjord and also in cultivated fish. There was a strong relationship between concentrations of VTG and fish size. There was no evidence that the presence of VTG in the plasma of males is a natural part of their life cycle. On the other hand, the size of fish at which these elevated VTG concentrations appear (ca. 5 kg) is about the size that cod change from feeding primarily on benthic invertebrates to mainly other fish, both benthic and pelagic. The possibility is suggested that large cod pick up oestrogenic endocrine disrupters through the food chain. 相似文献
14.
Fish-farming structures are widespread in coastal waters and are highly attractive to wild fish. Several studies have estimated that tons to tens of tons of wild fish aggregate around fish farms. These estimates assumed that the majority of wild fish are concentrated immediately beneath farms, although this assumption has never been explicitly tested. We tested the hypothesis that abundances of wild fish would be greatest immediately beneath farms and progressively diminish with distance at 4 full-scale coastal salmon (Salmo salar) farms in Norway. At each farm, fish were counted with a video-camera system at 5 different distances from the cages (farm = 0 m, 25, 50, 100 and 200 m) throughout the water column on three separate days. Combined across all locations and times, the total abundance of wild fish was 20 times greater at the farm than at the 200 m sampling distance. Saithe (Pollachius virens) dominated assemblages at all 4 farms and were consistently significantly more abundant at the farm than at the 25–200 m distances. This ‘tight aggregation’ around farms corresponds to the reliance of saithe on waste feed when they school near farms. In contrast, patterns of distribution of both cod (Gadus morhua) and poor cod (Trisopterus minutus) varied among farms, with either highest abundances at the farm or a more even distribution of abundance across all 5 distances sampled. No specific pattern of aggregation was evident for the bottom-dwelling haddock (Melanogrammus aeglefinus). Our results suggest that the present 100 m no-fishing zone around salmon farms protects the greatest proportion of farm-aggregated saithe and cod from fishing during the daytime. However, whether this reduces their overall susceptibility to fishing requires further research regarding nighttime distribution and movements. 相似文献
15.
几种鳕鱼的生物学初步研究 总被引：6，自引：1，他引：6
本文在调查与校核资料的基础上，报告了狭鳕（Theragra chalcogramma)、蓝鳕（Micromesistius poutassou)、远东宽突鳕（Eleginus gracilis)、大西洋鳕（Gadus morhua)、太平洋鳕（Gadus macrocephalus)和黑线鳕（Melanogrammus aeglefinus)等六种经济鳕雪类分类地位、区系性质与分布。并对上述鳕雪主要形态特征进行了详细的描述，建立了狭鳕等五种鳕鱼体长与总重关系式，以期找出各鱼种的生长发育规律。 相似文献
16.
Market-oriented regional fisheries management—an analysis of four fish regions in the North Atlantic
《Ocean & Coastal Management》2003,46(9-10):917-941
What influence do exchange methods have on ex-vessel prices and what are the potential implications for the regional management of the fisheries? This paper undertakes an empirical analysis of exchange methods and ex-vessel prices for specific demersal fish controlled for fish size and quantity in four North Atlantic regions, including Iceland, North-Norway and Scotland. The methodology consists of a comparative analysis of total average price (TAP) and Anova analysis of monthly average prices of cod and plaice landed fresh during the period 1990–1999. Scotland's auctions have the highest TAPs for the species analysed whilst the lowest TAPs are returned from contract sales in Iceland and North-Norway. Icelandic auctions and Møre–Romsdal auctions adopt intermediate positions in this price hierarchy. Price differences are still present even when correcting for factors such as legal barriers, transport costs from different geographical locations, exchange fees and seasonal variations in supplies. The implications of these findings for current and prospective systems of regional resource and coastal management are then considered and the scope and need for further study is established. 相似文献
17.
Kastelein RA van der Heul S van der Veen J Verboom WC Jennings N de Haan D Reijnders PJ 《Marine environmental research》2007,64(2):160-180
World-wide many cetaceans drown incidentally in fishing nets. To reduce the unwanted bycatch in gillnets, pingers (acoustic alarms) have been developed that are attached to the nets. In the European Union, pingers will be made compulsory in some areas in 2005 and in others in 2007. However, pingers may effect non-target marine fauna such as fish. Therefore in this study, the effects of seven commercially-available pingers on the behaviour of five North Sea fish species in a large tank were quantified. The species tested were: sea bass (Dicentrarchus labrax), pout (Trisopterus luscus), thicklip mullet (Chelon labrosus), herring (Clupea harengus), and cod (Gadus morhua). The fish were housed as single-species schools of 9-13 individuals in a tank. The behaviour of fish in quiet periods was compared with their behaviour during periods with active pingers. The results varied both between pingers and between fish species. Sea bass decreased their speed in response to one pinger and swam closer to the surface in response to another. Thicklip mullet swam closer to the bottom in response to two pingers and increased their swimming speed in response to one pinger. Herring swam faster in response to one pinger, and pout and cod (close relatives) showed no behavioural responses to any of the pingers. Of the seven pingers tested, four elicited responses in at least one fish species, and three elicited no responses. Whether similar responses would be elicited in these fish species in the wild, and if so, whether such responses would influence the catch rate of fisheries, cannot be derived from the results of this study. However, the results indicate the need for field studies with pingers and fish. Based on the small number of fish species tested, the present study suggests that the higher the frequency of a pinger, the less likely it is to affect the behaviour of marine fish. 相似文献
18.
《Marine Policy》2016
Exotic marine fish products are increasingly appreciated in China. In this study, 100 samples of Cod, Salmon and Tuna products were collected from supermarkets in Shanghai, Nanjing and Hangzhou. First the information reported on the label were assessed in the light of the Chinese legislation, paying particular attention to the fish names and the geographical origin. Then, a comparative analysis of the official trade denominations adopted by five European countries (Italy, France, Germany, Spain and United Kingdom) for Cod, Salmon and Tuna was performed. Finally, the Chinese names of the species considered in the EU list were verified consulting the available international lists. Overall, 95% of the samples employed just generic names. In particular, 98% of Salmon and 100% of Tuna products were generically labeled while the labeling of Cod products was more diversified, even though 80% reported misleading or fake denominations. The results of this work highlighted the lack of a mandatory legislation on seafood traceability and of an official naming system. In particular, this study propose the introduction of a detailed Chinese naming system based on the Chinese Latin Dictionary for Seafood Names, following the EU approach. In fact, inaccurate labeling can have both economic and health implications for consumers as well as it may distort the true abundance of fish stocks. These drawbacks can be particularly serious considering the pivotal role of China in the global fishery industry. 相似文献
19.
《Marine Policy》2017
The Spanish market for canned fish is one of the biggest in the world. It is still largely supplied by a robust national industry which has survived globalisation when all other European countries failed to preserve their two-century old industry. What is so special about this relationship between Spanish consumers and canned fish? This research analyses the nature of the demand for canned fish, and particularly canned tuna, a rather inexpensive and storable food product, to show how Spanish households are sensitive to price and income changes. The price and expenditure elasticities are estimated through a time-based Almost Ideal Demand System (AIDS) model. A Johansen’s multivariate time-series analysis was developed through a vector error correction model, the misspecification tests supporting the use of this model. The empirical analysis found that the Spanish demand for canned fish in Spain is rather price inelastic, whatever the species, but substitutability is found between the different canned fish products. The results also demonstrate that canned tuna over-reacts positively to expenditure changes compared to other fish species, presenting a nature of luxury good compared to other canned fish products. 相似文献
20.
Trophic structure of the Barents Sea fish assemblage with special reference to the cod stock recoverability 总被引：1，自引：0，他引：1
The species composition and trophic structure of the Barents Sea fish assemblage is analysed based on data from research survey trawls and diet analyses of various species. Atlantic cod was the dominant fish species encountered, accounting for more than 55% by abundance or biomass. Only five fish species (long rough dab, thorny skate, Greenland halibut, deepwater redfish and saithe) were sufficiently abundant to be considered as possible food competitors with cod in the Barents Sea. However, possible trophic competition is not high, due to low spatial and temporal overlap between cod and these other species. Analyses of fish assemblages and trophic structures of the Barents Sea and other areas (North Sea, Western Greenland, Newfoundland-Labrador shelf) suggest that Barents Sea cod is the only cod stock for which the ability to recover may not be restricted by trophic relations among fishes, due to a lack of other abundant predatory species and low potential for competition caused by spatial-temporal changes. 相似文献