首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 11 毫秒
1.
Addressing social and economic considerations is crucial to the success of Marine Protected Area (MPA) planning and management. Ineffective social assessment can alienate local communities and undermine the success of existing and future MPAs. It is rare to critique the success of methods used currently to incorporate social and economic considerations into MPA planning. Three Australian MPA planning processes covering three states and incorporating federal and state jurisdictions are reviewed in order to determine how potential social impacts were assessed and considered. These case studies indicate that Social Impact Assessment (SIA) is under-developed in Australian MPA planning. Assessments rely heavily on public participation and economic modelling as surrogates for dedicated SIA and are followed commonly by attitudinal surveys to gauge public opinion on the MPA after its establishment. The emergence of issues around public perception of the value of MPAs indicates the failure of some of these proposals to adequately consider social factors in planning and management. This perception may have potential implications for the long term success of individual MPAs. It may also compromise Australia's ability to meet international commitments for MPA targets to gazette at least 10% of all its marine habitats as MPAs. Indeed, this is demonstrated in two of the three case studies where social and economic arguments against MPAs have been used to delay or block the future expansion of the MPA network.  相似文献   

2.
Izvestiya, Atmospheric and Oceanic Physics - Results are presented from assessing forest ecosystem disturbances in the forest–steppe zone of Russia’s Central Chernozem region in the...  相似文献   

3.
This paper uses a quarterly, game-theoretic model of the Northeast Atlantic mackerel to study the fishing strategies of five players: the EU, Norway, the Faeroe Islands, Iceland, and the international fishery on the high seas. Data on the spatial distribution of fish catches (1977–2011) are used to model changes in the distribution of the mackerel stock. The Nash equilibrium solutions predict a severe decimation of the stock through overfishing, either by parties (Iceland, the Faeroe Islands) that refuse to cooperate or by a general absence of cooperation. There is a wide discrepancy between this prediction and reality, as the stock seems, at most, only moderately overexploited, despite non-cooperation by Iceland and the Faeroe Islands. It is conjectured that these parties, and others, may engage in a degree of quasi-cooperation that falls somewhat short of full cooperation but avoids the extreme destruction of the Nash equilibrium. This tacit cooperation can be seen as being maintained by a mutually assured destruction of the fisheries of all parties in case they go to the logical extremes of non-cooperation.  相似文献   

4.
A large number of the marine protected areas (MPAs) designated in Spain have been proposed by public authorities or conservation NGOs in conjunction with their own administrations and other social and economic stakeholders. The only examples to date of MPAs proposed by fishing interests – the fishermen and their organizations – are located at Cedeira and Lira, two small communities in North West Spain. These fishing interests have been involved in these two proposals from the start, including design and development, as well as internal awareness-raising. However, 5 years from the outset, both marine reserves have failed to meet the conditions and essential requirements of a successful fisheries management system. This paper evaluates how the artisanal fishing sector has been identified with the idea of sustainability; and how the role and power relations of the Galician regional administration acquired both the key institutions of co-management and their associated functions which have conditioned the consolidation process of these marine reserves.  相似文献   

5.
Depositional environment can change through geological time. This paper describes a delta that evolved from river-dominated into tide-dominated. The delta is located in the Ya13-1 field of the South China Sea. Understanding the change that occurred in the deltaic setting is important because the change in depositional environments led to changes in spatial distribution of facies and other rock properties.The Oligocene sediments of the third member of the Lingshui Formation in the Ya13-1 field were deposited in a river-dominated delta, and later impacted by marine flooding, fluvial and tidal currents. As a result of these different influences, the early-stage depositional micro-facies and the sandbody distributions are quite different from those of the later stage. At the early stage, fluvial influences prevailed, resulting in a fluvial-dominated delta plain and deposition of many linguoid sand bars in the delta front. During the late stage of deposition, tide-dominated delta fronts were developed extensively and finger sand bars deposited abundantly in the delta front as a result of the tidal influence.Ya13-1 gas field is laterally divided into two large subareas and vertically into eight stratigraphic packages. Because of the different influences of marine flooding that resulted in different interbeds and intercalations, the number of stratigraphic packages in the south is different from that in the north. The change of deltaic depositional environments also resulted in different reservoir properties between the northern and southern regions as the reservoir properties of mouth bars are generally better than distributary channels. These depositional characteristics significantly impact the development of the field.  相似文献   

6.
In this study, we exposed female medaka to aqueous solutions of o,p′-DDT until tissues residues reached approximately 100 g/g. Male offspring of exposed females and unexposed males that were raised to 6 months of age differed from untreated controls in their response to subsequent 4-day static exposure to 17-β-estradiol (E2; 12 μg/l as determined by steroid EIA). Homogenized liver samples from males from DDT treatments, females from DDT treatments, control males and control females produced two vitellogenin bands on a Western blot with no qualitative differences in band size and location between the groups. To quantify the relative level of vitellogenin, 5 μg of protein from each sample was analyzed by slot blot. A statistical comparison revealed a significant difference in optical density of the slots between control males and DDT exposed males (analysis of variance, n=18, P=0.021; Tukey test, n=9, P=0.047) indicating that previous transgenerational exposure to DDT enhanced the vitellogenic response to E2 exposure in males. These results indicate that exposure to estrogenic chemicals may produce an ‘estrogen memory’ which potentiates the response to a subsequent exposure event.  相似文献   

7.
The objectives of this study were to (1) investigate whether the availability of suitable zooplankton prey limits the distribution of the coastal larval areas of pike (Esox lucius) in two archipelago areas of the northern Baltic Sea and (2) compare the availability of zooplankton prey in spring between different types of coastal littoral habitat. According to the results, reed belt habitats formed by Phragmites australis constitute hot spots for zooplankton prey in the coastal ecosystem. During the spring, reed-covered shores of the inner archipelago maintained more than 10 times higher densities of copepods and cladocerans, the preferred prey for larval pike, compared to the other studied shores. Temperature conditions were also most favourable in the reed belt habitat. Thus, the reed belts of the inner and middle archipelago were shown to form the best habitat for larval pike in the coastal area of the northern Baltic Sea, and this was also the only habitat where pike larvae were found. Our results suggest that the poor survival and recruitment of pike in the outer archipelago, however, cannot exclusively be explained by sub-optimal feeding conditions of the larvae. There are also other important factors, presumably connected to the exposure to the open sea, that affect the distribution of the pike larvae. Our results, however, highlight the importance of sheltered coastal reed belt shores as reproduction habitat for spring-spawning fish in the northern Baltic Sea. Further, this study disproves the assumption that the seaweed bladder wrack (Fucus vesiculosus) forms a reproduction habitat for pike in the coastal area.  相似文献   

8.
The small, genetically distinct population of Indo-Pacific bottlenose dolphins (Tursiops aduncus) in Port Stephens, New South Wales (NSW), is the target of the largest dolphin-watching industry in Australia and falls within the recently created Port Stephens—Great Lakes Marine Park. The effectiveness of Speed Restriction Zones (SRZs) as a management tool in this area was investigated during their second year of implementation by comparing dolphin usage and behaviour to adjacent Control Zones (CZs) of similar habitat. For this purpose, boat-based surveys and focal follows of dolphin groups were carried out in the zones between August 2008 and August 2009. Results showed that SRZs were more intensely used by dolphin-watching boats in summer. There was no change in dolphins’ behaviour and group structure in the presence of dolphin-watching boats in SRZs when compared to dolphin groups within CZs in any season. Dolphin groups including calves used SRZs less during summer. The latter may indicate a shift in area utilisation for those groups during intense boat traffic by dolphin-watching operators. CZs were more important than SRZs as foraging grounds for dolphins in summer. This indicates that SRZs as specified are not effective at minimising boating impacts and that the location of these zones should in time be revised. This is important information for management of dolphin-watching within this marine park and an example of adaptive management in progress. Moreover these results are relevant for conservation of dolphins and the management of dolphin-watching industries elsewhere, particularly new industries, where management strategies may incorporate marine protected areas including zoning plans.  相似文献   

9.
《Journal of Sea Research》2010,63(4):229-237
Length growth in relation to water temperature was studied for Crangon crangon (L.) from two populations at the northern and southern edges of its distributional range to determine whether counter-gradient growth compensation occurs. In crustaceans, growth rate depends on the time between moulting events (intermoult period) and the size increase at moult (moult increment). In this study, the period between moults was shorter at higher temperature, ranging respectively from about 11 days at 25 °C to 27 days at 10 °C at southern edge, and from 10 to 24 days at the same temperatures at the northern edge. Moult increment showed a large variability, from 1.5 to 2.7 mm with no clear trend with temperature at the northern edge; and decreasing from about 2.7 mm at 10 °C to about 1.5 mm at 25 °C at the southern edge. As a result, the temperature effect on the overall growth rate differed between shrimps from the north and those from the south, suggesting counter-gradient growth compensation. At the northern edge, mean growth increased from about 0.12 mm d 1 at 10 °C to about 0.23 mm d 1 at 25 °C, while at the southern edge, growth was lower, about 0.08 mm d 1 at 10 °C and increased to about 0.16 mm d 1 at 25 °C. Maximum observed growth rates of shrimps from the north were also higher and ranged from 0.17 mm d 1 at 10 °C to 0.89 mm d 1 at 25 °C, while shrimps from the south grew at a maximum of 0.08 to 0.75 mm d 1 respectively at 15 and 20 °C. Sex and size differences were also found, with males growing slower than females and at a decreasing growth rate with increasing size. Implications for the brown shrimp's life cycle are discussed.  相似文献   

10.
To assess differences in fish assemblage structures among microhabitats within the surf zone of an exposed sandy beach, three microhabitats (onshore current, rip current, and river adjacent sites) were sampled at Sanrimatsubara Beach, western Japan, in May, August, and November 2002 and 2003. Although several physical variables (e.g. wave height, current speed, turbidity, salinity, and sand particle size) and major prey abundances (calanoid copepods and mysids) differed among the sites, no significant differences were apparent in the numbers of fish species and individuals among the sites in any month in either year. In addition, species and individual numbers of two dominant feeding groups (zooplankton feeders, and epiphytic and benthic crustacean feeders) did not show any significant responses to among-site differences in prey abundance. Cluster and ordination analysis confirmed the similarity in fish species composition among the three sites. These results indicated that the surf zone fish assemblage structures were similar among the microhabitats in spite of there being microhabitat-related differences in abiotic and biotic environments.  相似文献   

11.
Food availability is a key variable influencing breeding performance and demography of marine top predators. Due to methodological problems, proportionality between fish abundance and availability is often assumed without being explicitly tested. More specifically, better breeding performance of surface-feeding seabirds at times of large prey stocks suggests that prey availability is also a function of prey abundance. Using vertically resolved stow net sampling we tested whether local abundance and length composition of pelagic fish are reliable predictors of the availability of these fish to surface-feeding Common Terns (Sterna hirundo) breeding in the German Wadden Sea. Prey fish were found to concentrate below the maximum diving depth of the terns. Individuals caught close to the surface were in most cases smaller than conspecifics caught at greater depth. Correlations between fish abundance within and out of reach of the terns appeared to be both species- and site-specific rather than driven by overall fish abundance. Vertical distribution patterns of the terns' main prey fish could be explained as anti-predator behavior, reducing prey availability to the terns. In 2007, when breeding performance was much better than in 2006, herring and whiting were much more abundant, suggesting that overall prey abundance may also increase prey availability in habitats other than those represented by the stow net sampling.  相似文献   

12.
In Piriápolis (Uruguay) and Paraty (Brazil), artisanal fishers view fishing as a way of life, rather than just a job. The freedom of fishing and an inherent satisfaction in the occupation figure large in fishers' attachment to it. There are strong indications, however, that the relationship of fishers to fishing is changing. First, while fishers from both areas wish to keep fishing in the future, they are moving into different occupations or supplementing their work in fishing with other employment. Second, artisanal fishers from Piriápolis and Paraty identified fishing as an undesirable occupation for their children because they believe that in the future fishing will no longer be a viable occupation. Nonetheless, despite the wishes of their parents, young men and women in Piriápolis and to a much lesser degree in Paraty continue to become involved in fishing and fishing-related activities. The paper uses a social wellbeing perspective to interpret fisher responses to the changing circumstances they face. Wellbeing is a lens to understand the distinctive features of artisanal fisheries and helps to understand fishers' disenchantment with fisheries governance processes, in a scenario where participation is being promoted by the state in Uruguay and Brazil. The implications of these findings for state efforts to promote fisher participation in governance are discussed.  相似文献   

13.
We report a conspicuous benthic diatom bloom on an Antarctic fjord shallow seafloor, which has not been reported elsewhere in Antarctica. A thick and massive growth of benthic diatoms was covering or being entangled with a variety of common benthic megafauna such as stalked ascidians, sponges, tubedwelling polychaetes, gastropods, bryozoans, and others. This finding is an outcome of recent investigations on benthic communities in Marian Cove, King George Island, where glacier retreat has been proceeding quickly for the past several decades. Dominance of benthic diatoms during the austral summer has been frequently reported in shallow Antarctic nearshore waters, which in turn indicates their potential as a primary food item for secondary producers living in this harsh environment. However, previous blooming records of the benthic diatoms were primarily based on data from water column samples. We are the first to report observational evidence of shallow seafloor substrates, including the massive blooming of benthic diatoms and their associations with common benthic megafauna in an Antarctic fjord.  相似文献   

14.
15.
Recent years have seen increasing interest in the concepts of compensation and ecosystem services. Regulation systems in the United States dealing with environmental protection (Superfund Act, Oil Pollution Act, National Environment Policy Act, Clean Water Act, Endangered Species Act, etc.) require those responsible for damage to ecosystem services to compensate for it “physically” and restore these services for the benefit of the entire population. This article, using simple indicators of compensation identified in the literature, attempts to analyze what types of ecological compensation are adopted, how performance is assessed, how standards on ecological equivalencies are adopted, and what are the costs of this compensation. To perform this analysis, compensatory measures carried out during the last ten years in the case of coastal and marine ecosystems in Florida have been addressed. The results show that: analysis criteria for the equivalencies between ecosystem services lost due to damage and ecosystem services gained due to compensatory measures are questionable; most compensation monitoring is for a relatively brief period of time and the data obtained during this period may be insufficient for assessing the net effect of the compensatory measure; the weaknesses regarding criteria for the equivalencies and the uncertainty about the relevant time-scale can be counter-balanced by increasing the area of compensation, a problematic solution at best.  相似文献   

16.
China and Japan’s June 2008 agreement in principle on maritime cooperation in the East China Sea raised hopes of a significant breakthrough in the parties' complex and long-standing disputes in the area. Subsequent progress towards the realisation of a legally binding, formal treaty on, for example, offshore petroleum joint development has been slow to materialise. In fact, the area under dispute appears to have become more rather than less extensive. This paper examines competing maritime and sovereignty claims in the East China Sea together with progress towards maritime cooperation in the context of overlapping jurisdictional claims. The paper identifies some of the key challenges that need to be overcome in realizing a functioning joint resource management regime in the East China Sea.  相似文献   

17.
This study examined possible environmental factors that affect prokaryote variables in surface waters (upper 100 m of water column) in the Canada Basin, western Arctic Ocean. We collected data on prokaryote abundance and heterotrophic production ([3H]leucine incorporation) at eight stations deployed along a slope-to-offshore transect during September 2009. Prokaryote production and growth tended to increase with increasing chlorophyll a (Chl. a) and temperature and with decreasing salinity. The combination of Chl. a, temperature, and salinity accounted for a large fraction (74%) of the variability in prokaryote production, with the highest contribution made by Chl. a (r 2 = 0.56), followed by salinity (r 2 = 0.14) and temperature (r 2 = 0.03). Similarly, the variability in prokaryote growth rate was largely accounted for by the combination of the three environmental variables (overall r 2 of 0.64), with Chl. a making the largest contribution to variability (r 2 = 0.33), followed by salinity (r 2 = 0.27) and temperature (r 2 = 0.05). These data are consistent with the notion that organic matter supply associated with freshwater inputs to surface layers can result in enhanced prokaryote production and growth in the Canada Basin. Our results provide insights into the regulation of the microbial loop in the Canada Basin where freshening has been proceeding rapidly due to increasing river discharge and sea-ice melting.  相似文献   

18.
Lately, across‐shore zonation has been found to be more important in structuring the nematode community of a tropical macrotidal sandy beach than microhabitat heterogeneity. To evaluate whether this zonation pattern applies to a temperate beach, a macrotidal ridge‐and‐runnels sandy beach in the North Sea was studied. We investigated whether a similar zonation occurs in sandbar and runnel microhabitats, and whether the runnels harbour a different community from the subtidal. Our results indicate that nematode communities from runnel and sandbar habitats are significantly different. In addition, horizontal zonation patterns for nematode communities differ between both habitats. Nematode assemblages from sandbars are divided to lower, middle and upper beach while upper and middle runnels cluster together. The subtidal and upper runnels showed dissimilar nematode assemblages, although runnels showed the same dominant species (Daptonema normandicum), which increases its abundance towards the upper runnels. This study illustrates the importance of microhabitat heterogeneity, which resulted in different zonation patterns across the sandy beach examined. The divergent zonation between sandbars and runnels in the macrotidal temperate sandy beach, compared with the pattern observed for a subtropical sandy beach with similar morphodynamics, indicates that generalizations about nematode distribution patterns should be made with caution.  相似文献   

19.
20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号