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 687 毫秒
1.
This study aimed to compare the spatio-temporal distribution of demographic groups of Hepatus pudibundus in the Ubatuba Bay, São Paulo, Brazil, over a 20-year interval. Two 1-year samplings were conducted: the 1st period (P1) ran from September 1995 to August 1996 and the 2nd period (P2) ran from September 2016 to August 2017. Samples were taken from five stations that differed in depth (5, 10, and 15 m) and location (exposed area and sheltered area), aboard a shrimp fishing boat. Over the 20-year period, the percentage of fine sediment increased in all stations. In total, we captured 865 H. pudibundus individuals in the P1 and 4,222 in the P2. The higher abundance seen in the P2 may have been caused by the effects of an intense ENSO event in Ubatuba, as well as co-occurring protective actions against fisheries activities in the region. The spatial distribution also changed after 20 years: In the P1, H. pudibundus were more concentrated in the 15 m station and exposed area, but they shifted to the sheltered area in the P2. This change may be related to the increase of fine sediments in this area, and to the fact that it is naturally protected from fisheries. According to the correspondence analysis, the abundance of males and juveniles was correlated with spring and winter, respectively. In the P1, females were more abundant in spring, whereas in the P2 they were more abundant in summer, which may be explained by a higher nutrient availability to the larvae in the summer of the P2. Our comparisons over the 20-year interval revealed that the spatio-temporal distribution of H. pudibundus has changed and that the population is well established in Ubatuba Bay.  相似文献   

2.
Managing small-scale fisheries in a developing country like the Philippines is very challenging because of high pressures from expanding fishing population, poverty and lack of alternative options. Thus, resource-focused fisheries management initiatives such as marine protected area (MPA) establishment will likely result in further marginalization of the poor fishers which could pose more serious problems in coastal communities. In this study, the status of small-scale fisheries in 44 coastal towns in the Philippines was assessed using FISHDA (Fishing Industries' Support in Handling Decisions Application), a simple decision support tool which requires minimal or easily-generated data. Results showed that 68% (30 out of 44) of the studied towns have unsustainable fisheries unless 58% of their fishing grounds are protected from all fishing activities. Alternatively, 53% of the active fishers in towns with unsustainable fisheries must totally stop fishing to avert fishery collapse. Alarming as it may sound, this is still an underestimate as catches incurred by the highly efficient and destructive illegal fishing activities such as blast, poison and large-scale fishing, which are reported to be still rampant in many coastal areas in the Philippines, were not accounted for in this study. This study demonstrated that MPAs alone may not be enough to avert fishery collapse even if MPA size is increased from the current 3% to 15% of the municipal waters, i.e. up to 15 km from the shore, as required by the Philippine law. Various challenges confronting the fishery and important recommendations to address them are further discussed.  相似文献   

3.
The inner shelf waters off Southeastern Brazil are periodically enriched by bottom intrusions of the cold and nutrient‐rich South Atlantic Central Water (SACW), which is transported offshore by the Brazil Current. This study examined the temporal contrasts in abundance and structure of pelagic copepod assemblages in a neritic station off Ubatuba, in relation to hydrography and phytoplankton biomass, to investigate the effects of SACW bottom intrusions on copepod population dynamics during three consecutive years. The water‐column characteristics shifted from a well‐mixed, more turbid and phytoplankton‐poor scenario during subsidence conditions to a stratified, less turbid and high Chl‐a concentration scenario during SACW bottom intrusions, leading to increased copepod diversity, abundance, and biomass. The rise in copepod diversity during SACW intrusions was related to the contribution of oceanic species in addition to coastal water species. The copepod community was numerically dominated by small‐sized species, such as Oncaea waldemari, Oithona plumifera, and clausocalanid and paracalanid copepodids, regardless of seasonality and SACW intrusions. Some large calanoid species contributed considerably to the total copepod biomass during intrusions. In addition to confirming that SACW seasonal intrusions play a key role in pelagic processes off Southeast Brazil, this study showed that the multiannual variability of SACW seasonal intrusions is important in regulating the structure and dynamics of copepod communities in this subtropical area.  相似文献   

4.
  相似文献   

5.
We investigated the reproductive biology of the planktonic harpacticoid copepod Euterpina acutifrons, including morphometric data, egg production rates (EPR) and viability, and weight‐specific egg production. Experiments were carried out during 1 year in an inner‐shelf area off Ubatuba (SE Brazil), a site seasonally influenced by bottom intrusions of the relatively cold and nutrient‐rich South Atlantic Central Water (SACW). We hypothesized that E. acutifrons attain higher reproductive rates when SACW penetrates in this region. Live females were incubated individually in cell culture plates during two periods of 24 h each, under controlled temperature and light conditions. Euterpina acutifrons carried on average 16.9 ± 6.9 eggs·sac?1, ranging between 10.8 ± 5.7 and 30.8 ± 7.4 eggs·sac?1. Estimated EPRs ranged from 6.3 ± 3.4 to 13.6 ± 4.2 eggs·female?1·day?1, with mean weight‐specific egg production rates of 0.06 ± 0.04 and 0.17 ± 0.08 per day. Euterpina acutifrons was not directly influenced by SACW intrusions, but body length and clutch size were positively related to temperature and chlorophyll content. Egg hatching time was clearly dependent on water temperature, as a 2 °C increase resulted in a decrease of 15 h in egg hatching time. This shows that even a small variation in temperature may considerably affect E. acutifrons population dynamics. Reproductive traits of this pelagic harpacticoid seem, therefore, to be controlled by the trade‐offs between increased food supply and the metabolic demands at low temperatures associated with SACW bottom intrusions toward this coastal area.  相似文献   

6.
Upwelling areas are among the most productive ecosystems on the planet, influencing the biology of marine organisms. This study investigated the population dynamics of the shrimp Artemesia longinaris in two regions in southeastern Brazil, one inside (Macaé—Rio de Janeiro State) and one outside (Ubatuba—State of São Paulo) the Cabo Frio upwelling area. The aim was to verify the influence of the upwelling phenomenon on the abundance, growth, longevity, size of sexual maturity, and reproductive period of the species. In total, 188,902 individuals were captured at Macaé and 3,461 at Ubatuba. Individuals captured at Macaé showed larger maximum size, higher longevity, and slower growth rate, besides reaching sexual maturity at larger sizes than at Ubatuba. Continuous reproduction was observed in both regions, with juvenile recruitment peaks in spring and summer. Local conditions observed at Macaé were influenced by the Cabo Frio upwelling zone, characterized by productive and cooler waters that are around 20°C during most of the year. The upwelling phenomenon is probably the main factor influencing the population parameters studied here, changing the geographic patterns previously observed for the variation of these parameters in A. longinaris.  相似文献   

7.
The habitat characteristics and spatial segregation of the two common gobies Gobius fallax Sarato, 1889 and Gobius auratus Risso, 1810 were investigated by fish frequency and abundance estimates through visual counts in the northern Adriatic Sea. The latter species is represented by a recently described, unusual colour morph in the northern Adriatic Sea. Gobius fallax was observed at five of the nine locations examined and its abundance did not differ between two of three transect locations at Piran (Slovenia) and at the western coast of Cres (Kvarner region, Croatia). Gobius auratus was not found in the Gulf of Trieste but was present at several Kvarner locations, and co‐occurred with G. fallax at one location at Cres. Both inhabit rocky substrates but they show different preferences for substrate inclinations and bathymetric segregation. Gobius fallax was most frequent between 2 and 8 m depth and was most abundant on substrate inclining less than 30°. Its highest abundance over entire transects was 0.3 indiv.·m?2 but within certain transect sections this increased to 1.25 indiv.·m?2. Gobius auratus attained its highest abundance in depths below 8 m and at substrate inclinations between 30 and 90°. This species attained its highest values at the western coast of Cres, where it reached a maximum of 1.5 indiv.·m?2 over entire transects but even up to 3.0 indiv.·m?2 in certain transect sections. At Krk, the maximum abundance over entire transects was only 0.3 indiv.·m?2.  相似文献   

8.
One of the aims of Mediterranean marine protected areas (MPAs) is to increase populations of exploited species, such as the European spiny lobster (Palinurus elephas), which is considered a key species for its commercial and ecological value. Monitoring of temporal patterns in abundance of early benthic stages of P. elephas indicated that predation may be higher inside the Medes Islands MPA relative to adjacent control sites. Tethering experiments were performed to test whether predation rates actually differed within and outside the MPA. Relative mortality of recently‐settled juveniles inside the MPA was much higher than in control sites in adjacent non‐protected areas. Treatments with and without shelter indicated that predation on recently‐settled juvenile spiny lobsters was moderated by the availability of suitable shelter. The decline or absence of fish predators in the fished area may be the reason why juvenile lobsters outside the MPA experience lower predation than within the MPA.  相似文献   

9.
Small-scale fisheries and the communities they support are often given the protection of designated fishing zones from which non-artisanal vessels are excluded. This paper looks at one example of this approach, the trawl ban introduced in the Gulf of Castellammare (NW Sicily), focussing on the economic sustainability of the artisanal fishery currently operating within the protected area. The consequences of lifting the trawl ban and how far this would jeopardise the sustainability of the artisanal fishery are explored via an analysis of the financial viability of trammel net vessels under alternative assumptions concerning catch rates. The paper also investigates fishermen's attitudes towards the trawl ban and their predisposition either to remain in the fishery or to quit in the event of the ban being removed.  相似文献   

10.
A ten-year time series (1998–2008) from a trawl survey of the continental slope of the NE Atlantic was analyzed to assess temporal variation in the abundance and length frequency of seven species of deepwater grenadier fish. This period coincided (in 2003) with the regulation of deepwater fisheries in this area. None of the species declined in numbers or biomass over the period, and 2 species significantly increased. This suggests that the declines in abundance of these deepwater species following the onset of fishing in the 1970s may now have stabilized, albeit at much lower levels than the virgin biomass. Although two metrics of body size (mean length and maximum length) did not show any evidence for consistent decrease over time, there were significant changes in the overall length–frequency distributions. The species found in shallower depths (500 m) had a greater number of larger individuals in 2008 whereas those found deeper (1500 m) tended to have a greater number of smaller individuals. This suggests the presence of a lagged indirect effect of fishing on species that live beyond the actual depths that fishing takes place.  相似文献   

11.
The giant diatom Ethmodiscus was examined along an east–west transect at 28–30°N during 2002 and 2003 to determine if abundance, chemical composition or physiological status of this largest of diatoms varied on the scale of 100's–1000's of km in North Pacific gyre. Abundance ranged from <0.1–>2.0 cells m−3 and supported the notion of an abundance mosaic reported previously. However, there was only minimal support for the relationship between abundance and nutrient concentration at 125 m reported previously. Cellular chlorophyll varied little along the transect (7.3–10.9 ng chl cell−1) except at the westernmost station. Cellular N and P quotas co-varied 3–4.5 fold (mean=50.8±3.7 and 3.7±0.8 nmol N and P cell−1) and yielded N:P ratios that closely clustered around the Redfield ratio (average=14.6±1.1). Only low levels of chlorophyll-normalized alkaline phosphatase (APase) activity were observed (0.4–2.5 nmol P μg chl−1 h−1) with APase activity lower than that in either the bulk water, or co-occurring Trichodesmium spp. and Pyrocystis noctiluca. The active fluorescence parameter Fv:Fm, a property sensitive to Fe stress, was uniformly high at all stations (average=0.73±0.04 for 2003, and 0.69±0.05 for 2002), indicating sufficient Fe for optimum photosynthetic competence. These results contrasted sharply with results from Rhizosolenia mats reported along the same transect where there was a significant decline westward in Fv:Fm. Both ferredoxin (Fd) and flavodoxin accumulated in cells of Ethmodiscus, resulting in Fd Index values of<0.6. Iron cell quotas ranged from 0.7–5.1 pmol Fe cell−1. When normalized to cytoplasmic volume, the Fe μm−3 was comparable to that of Escherichia coli. We note that the disproportionate contribution of the vacuole (with its high organic content) to total volume typical of large diatoms is a potentially significant source of error in Fe:C ratios and suggest that Fe should be normalized to cytoplasmic volume whenever possible to permit valid intercomparisons between studies. The composition, Fv:Fm data and Fe:C ratio suggest a relatively uniform population experiencing little N, P or Fe stress. The uncoupling of the Fd Index from these measures is consistent with previous findings showing that the expression of flavodoxin can be characterized as an early stress response and that its accumulation is not necessarily correlated with physiological deficit. Ethmodiscus appears to be well adapted to some of the most oligotrophic waters in the ocean. Because it is an important sedimentary marker, the biology of living Ethmodiscus provides insights into the source of extensive Ethmodiscus oozes. Mass sedimentation after frontal accumulation has been suggested as a source for these oozes. Our data contain no evidence that the flux is linked directly to Fe, N or P stress.  相似文献   

12.
Climate variability and pelagic fisheries in northern Chile   总被引：5，自引：0，他引：5  
A time series analysis of long-term climate variability in northern Chile (18°21′–24°00′S) shows anomalies associated with the El Niño events and the longer warm period observed since 1976, followed by a cooling trend since mid 1980s. The succession of pelagic fisheries, anchovy (Engraulis ringens) and sardine (Sardinops sagax), occurring in this fishing zone was analyzed taking into account the landings, the CPUE abundance index, the fishing effort, and the environmental variables. The anchovy production model is a negative linear function of fishing effort and turbulence. For sardine, the production model is a negative linear function of fishing effort and a quadratic function of the sea surface temperature.An analysis of the relationship between recruitment, adult biomass and the environment shows that the annual recruitment of anchovy increases with turbulence intensity until wind speed reaches a value of 5.46 m s−1, decreasing for higher values. For sardine, the recruitment increases with turbulence intensity until 5.63 m s−1, stabilizing thereafter.It is deduced that the climatic variations associated to the El Niño events affect the abundance of coastal pelagic fishes, without forgetting the most likely effects upon its distribution and the fishing effort. However, it is the long-term variability that mainly affects the fishing activity.  相似文献   

13.
In Palau, Ngerumekaol and Ebiil Channels are spawning aggregation sites that have been protected from fishing since 1976 and 2000, respectively. Groupers and other targeted fisheries species were monitored monthly over a 1.5 year period at these two spawning aggregations and two nearby exploited reference sites where grouper formerly aggregated to spawn. At the protected aggregation sites, three grouper species (Plectropomus areolatus, Epinephelus polyphekadion, and Epinephelus fuscoguttatus) accounted for 78% of the abundance and 85% of the biomass of all resource species surveyed but comprised <1% of the total abundance and biomass at reference sites not protected from fishing that formally harbored spawning aggregations. Abundance and biomass of grouper species pooled were 54% and 72% higher, respectively, at Ngerumekaol compared to Ebiil. Comparisons with data from the same locations in 1995–1996 showed order of magnitude declines in abundance of E. polyphekadion at both locations. The lower numbers of E. fuscoguttatus and the near absence of E. polyphekadion at Ebiil may reflect the effects of previous and current overexploitation.  相似文献   

14.
Marine protected areas (MPA) have been widely suggested as a tool for both fisheries management and conservation goals. These multiple objectives are hard to achieve simultaneously as sustainable development implies the balance between the specific interests of conservation and economical activities. MPA success, namely for fisheries management, entails the implementation of restrictive measures that in a short-time frame may have negative effects on local fishermen communities. It is extremely important to evaluate their performance and effectiveness aiming at a quasi-optimal management, minimizing potential impacts on the social domain. In this study, a methodology for assessing the effectiveness of MPA as a small-scale fisheries management tool was developed, based on a set of indicators grouped in four dimensions (ecological, economic, social and management and governance). The indicators were scored individually according to an original score scale of five values and a median score was calculated for every dimension. Finally, the median overall score was calculated including the scores of the four dimensions. The scores were attributed for two distinct periods: before and after MPA implementation, in order to evaluate the performance of MPA. This methodology can be applied even with few scientific data available and taking into account experts and stakeholders’ judgements. The Arrábida MPA (Portugal) was used as a case study and it was found that with the implementation of the MPA social and economical aspects were impaired (median scores decreased near one value for the period after MPA implementation), while the other two dimensions showed an improvement trend. Thus, the overall score was the same before and after MPA implementation, an intermediate scale score. Results from the application of this method can give important indications about the state of an MPA and evaluate if the initial goals are being achieved through the implemented measures. The method is of easy communication and can be a useful tool for decision making and fisheries management processes.  相似文献   

15.
While the importance of top‐down control by grazers in maintaining tropical reef community structure is well known, the effect of ‘fishing down the food web’, which simultaneously changes the abundance and size of herbivorous fishes, has received less attention. As many fishing practices target the biggest fish and regulations often set minimum size limits, understanding size‐dependency of this controlling force is important. We evaluated the hypothesis that reduction in the abundance and size of fish, regardless of species identity, reduces the role of herbivory in controlling algal abundance on reefs and assessed variation in efficacy of this top‐down control on different types of common macroalgae. We quantified herbivory rates within cages of differing opening sizes on assemblages of four common algal species (Padina boryana, Dictyota bartayresiana, Halimeda opuntia and Galaxaura fasciculata) on two fringing reefs in Moorea, French Polynesia. Small acanthurids (<15 cm length) were the dominant herbivorous fish while other herbivorous fish were rare. For the two most palatable algae, the majority of herbivory occurred in open plots, with herbivory reduced by >50% in the largest opening cages (6 × 6 cm) where the maximum size fish entering was 12 cm in length (mean = 7.6, SE = 0.4). Fish entering medium (4.5 × 4.5 cm openings, maximum fish length = 8 cm, mean = 6.3, SE = 0.4) and small (3 × 3 cm openings, no fish observed entering) cages had herbivory rates approximately equal to the control treatment (1 × 1 cm openings). Consumption varied among algal species, with minimal consumption of physically and chemically defended algae and no pattern across treatments. Our results demonstrate a need for management plans to not only maintain the overall abundance of herbivorous fish but to protect the largest sizes for effective top‐down control of algal communities.  相似文献   

16.
Dynamics of suprabenthos (hyperbenthos) composition and biomass have been simultaneously analyzed at two sites (S1, S2) off the Ebro River Delta (western Mediterranean). The stations, separated by ca. 5 km, differed in terms of depth (S1, 47 m; S2, 61 m), distance to the river mouth (S2 south of S1 and farther from the mouth) and fishing activity (S1 is a fishing ground; S2 is in an area closed to fishing). Peracarids (gammaridean amphipods, mysids, and cumaceans) were dominant among suprabenthic taxa. Seasonality was the main explanation for changes in taxonomic composition, with two seasonal groups indicated by MDS analyses (late summer–autumn, August–September, and November 2003; early summer, June and July samples). Peracarids at both S1 and S2 showed a peak of abundance in early July, with the highest densities reaching 5400 individuals (100 m)−2 at S2. There was a sharp decrease of density in late July (S1) and August (S2), then an increase in August (S1) and in September (S2), respectively. A secondary peak of abundance occurred in November (S1) and December (S2). There was, therefore, a similar picture in the dynamics of suprabenthic peracarids at both sites, though with a delay of 1 month at the deeper S2. This pattern coincided with changes in river discharge (specifically, a decrease of suprabenthos when influx was below 200 m3 s−1 in the period June–September 2003), and with the formation of a thermal gradient (also in June–September 2003) between S1 and S2 associated with the 15 °C isotherm. In addition, the decrease of suprabenthos in late July–August also coincided with the massive occurrence of mucilaginous aggregates close to the bottom (at between 0 and 4 m above the bottom), in the usual habitat of suprabenthos. C/N ratios in sediments (an indicator of the degree of degradation of organic matter (OM)) increased during this peak abundance of mucilaginous aggregates. The impoverishment of sediments in total organic carbon (TOC) was parallel to the decline of suprabenthos in late July–August, which is consistent with negative or non-significant correlations (evidenced both by Spearman's r and multi-regression models) between suprabenthos densities and TOC. Zooplankton taxa (e.g., copepods, chaetognaths, and fish/crustacean larvae living in the entire water column) showed significant correlations with a number of environmental factors (basically temperature), in contrast to suprabenthos. In conclusion, suprabenthos abundance was influenced by a number of natural factors, both intra-annual (e.g., OM quality, river discharges) and inter-annual (e.g., accumulation of mucilaginous remains). Probably due to their swimming capability, suprabenthos were not influenced by trawling activity. Considering the high P/B exhibited by suprabenthic crustaceans in comparison to infauna, this compartment likely has an important role in regulating food webs in those communities submitted to high fishing impact.  相似文献   

17.
A closed fishing season is arguably the most important fisheries regulation measure implemented by the government of India in the new millennium. Applied mainly to the inshore trawl fishing fleet, the planners’ intention was a safe-guarding of capture fisheries. This article, which is based on fieldwork in seven harbour locations, considers the socio-economic consequences of the closed fishing season for trawler fishermen in the state of Tamil Nadu. It concludes that the success of the ban is based on cooperation between government and local fisher associations, and on broad agreement as to its necessity. Those who are impacted most by the implementation of the closed fishing season are lower-class workers and traders lacking opportunities for alternative employment.  相似文献   

18.
Nephrops norvegicus is an essentially sedentary species of lobster that forms the basis of valuable fisheries in the northwest Atlantic and western Mediterranean. Fishers exploiting a sedentary stock are likely to visit the most profitable (highest catch rate) areas first. Such spatial targeting of fishing effort is likely to have important consequences for stock monitoring and assessment. We used underwater television surveys of Nephrops burrow densities on the Farn Deeps grounds, northeast England, to describe changes in abundance and distribution between the beginning and end of a winter fishing season. Above a threshold of c. 0.6 burrows m–2, overwinter depletion increased with burrow density, consistent with fishing effort being targeted at the highest densities. A simple simulation model showed that this pattern of mortality is an expected consequence of spatially targeted fishing behaviour. The model also predicted that there is decreased spatial variability in density after fishing. An overall decrease in variability was not evident from the survey data, but geostatistical analysis indicated that there was “flattening” of the density profile along a north‐south axis, consistent with the dominant direction of commercial trawling. We concluded that Nephrops fishers are able to find and exploit the highest densities of their target species. A potential consequence is that catch per unit effort (CPUE) data used to monitor trends in this stock potentially could mask declines in stock abundance. CPUE might be more effective if analysed at finer spatial scales, but this is not currently possible. In the absence of these fine scale commercial data, fishery‐independent surveys (e.g., underwater television) are an important source of information on trends in stock abundance.  相似文献   

19.
The introduction of marine protected areas (MPAs) in Australia has resulted in an increase in the number and total area of ‘no-take’ zones. The resulting closures impact all forms of commercial and recreational fishing in and around them despite international recognition indicating that Australian fisheries were already well managed according to ecological sustainable development guidelines. Furthermore, it is recognised within Australia that most MPAs are not designed to provide protection from the full suite of known threats that can affect biodiversity and long-term ecosystem viability. By directing MPA management disproportionately towards comprehensive no-take zones that affect fishing practices that are already required by state and federal legislation to adhere to sustainability requirements, the suite of threats affecting both protected and unprotected areas can be left inadequately and/or inappropriately managed. It is shown in this paper that the modified definition of the Precautionary Principle, which was developed specifically for the MPA process in Australia, is not in keeping with accepted international definitions and guidelines for the use of precaution. It is argued that the development of a definition of precaution to justify a predetermined output (MPAs) devalues the sound use of scientific principles and diminishes the conservation outcome. Furthermore, by distracting efforts from determining and managing the full suite of recognised threats, the value of what protection is provided in Australia's marine protected areas is eroded further.  相似文献   

20.
The effects of recreational fishing on marine stocks and ecosystems have raised global concern in recent years. In Argentina, Southwest Atlantic, angling, netting and spearfishing of coastal bony fishes, sharks, rays and chimaeras are very popular pastime activities with more than 50 years of history. Despite the perceived traditional and economic relevance of these activities in the country, marine recreational fisheries were largely unregulated, and no official fisheries monitoring programs at the national level have been ever put in place. Except for a few particular systems for which some catch-and-effort data were collected by research institutions and non-governmental organizations, no comprehensive surveys aimed at describing the ecological, social or economic aspects of these fisheries have been made. Here, an updated review of the regulations in place for marine recreational fisheries along the Argentine coastline is presented. Of the five coastal provinces encompassing ca. 8400 km and about 20 latitude degrees (~36°S to 55°S) of coastline, only Buenos Aires province has a thorough legislation for its whole territory, which includes 15 protected areas. In the remaining provinces, the regulations for marine recreational fisheries are limited to a few protected areas (seven out of 37 coastal areas under provincial, national or shared jurisdiction). This lack of legislation encourages alleged recreational fishers to develop small-scale commercial fishing operations that are neither controlled nor monitored as such, contributing to the overexploitation of some key coastal stocks.  相似文献   

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