• <tr id="yyy80"></tr>
  • <sup id="yyy80"></sup>
  • <tfoot id="yyy80"><noscript id="yyy80"></noscript></tfoot>
  • 99热精品在线国产_美女午夜性视频免费_国产精品国产高清国产av_av欧美777_自拍偷自拍亚洲精品老妇_亚洲熟女精品中文字幕_www日本黄色视频网_国产精品野战在线观看 ?

    Variability of size-fractionated chlorophyll a in the high-latitude Arctic Ocean in summer 2020

    2022-10-18 12:59:44CAITingHAOQiangBAIYouchengLANMushengHEJianfengCHENJianfang
    Advances in Polar Science 2022年3期

    CAI Ting, HAO Qiang*, BAI Youcheng, LAN Musheng, HE Jianfeng & CHEN Jianfang

    Variability of size-fractionated chlorophyllin the high-latitude Arctic Ocean in summer 2020

    CAI Ting1,2, HAO Qiang1,2*, BAI Youcheng1,2, LAN Musheng3, HE Jianfeng3& CHEN Jianfang1,2

    1Key Laboratory of Marine Ecosystem Dynamics, Ministry of Natural Resources, Hangzhou 310012, China;2Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou 310012, China;3Key Laboratory of Polar Science, MNR, Polar Research Institute of China, Shanghai 200136, China

    The size structure of phytoplankton has considerable effects on the energy flow and nutrient cycling in the marine ecosystem, and thus is important to marine food web and biological pump. However, its dynamics in the high-latitude Arctic Ocean, particularly ice-covered areas, remain poorly understood. We investigated size-fractionated chlorophyll(Chl) and related environmental parameters in the highly ice-covered Arctic Ocean during the summer of 2020, and analyzed the relationship between Chldistribution and water mass through cluster analysis. Results showed that inorganic nutrients were typically depleted in the upper layer of the Canada Basin region, and that phytoplankton biomass was extremely low (mean= 0.05 ± 0.18 mg·m?3) in the near-surface layer (upper 25 m). More than 80% of Chlvalues were <0.1 mg·m?3in the water column (0–200 m), but high values appeared at the ice edge or in corresponding ice areas on the shelf. Additionally, the mean contribution of both nanoplankton (2–20 μm) (41%) and picoplankton (<2 μm) (40%) was significantly higher than that of microplankton (20–200 μm) (19%). Notably, the typical subsurface chlorophyll maximum (0.1 mg·m?3) was found north of 80°N, where the concentration of sea ice reached approximately 100%. The Chlprofile results showed that the deep chlorophyll maximum of total-, micro-, nano-, and picoplankton was located at depth of 40, 39, 41, and 38 m, respectively, indicating that nutrients are the primary factor limiting phytoplankton growth in the ice-covered Arctic Ocean during summer. These phenomena suggest that, despite the previous literatures pointing to significant light limitation under the Arctic ice, the primary limiting factor for phytoplankton in summer is still nutrient.

    phytoplankton, size-fractionated chlorophyll, sea ice, Arctic Ocean

    1 Introduction

    Sea ice is one of the most important environmental features of the Arctic Ocean ecosystem. In summer, the ice-covered area of the Arctic Ocean is approximately 8×106km2, accounting for nearly 60% of the total area. In winter, the Arctic Ocean is completely covered by sea ice, except for a few polynyas (Wang et al., 2005). The melting of sea ice produces approximately 40% of the surface meltwater in the Arctic Ocean (Eicken, 2002). Reduction of sea ice increases the surface water temperature of the Arctic Ocean, which could enhance both the availability of light and the growth rates of phytoplankton (Steele et al., 2008; Perovich and Richter-Menge, 2009). Light has generally been considered the primary limiting factor of phytoplankton growth in the high-latitude Arctic Ocean (Soltwedel et al., 2005, 2016; Wassmann and Reigstad, 2011). However, the melting of sea ice also enhances stratification and results in weaker mixing, which reduce the renewal of nutrients to the euphotic zone, further limiting primary productivity. The seasonal retreat and thinning of sea ice inhibit phytoplankton blooms by regulating the stratification and light conditions of the water column (Mundy et al., 2005; Leu et al., 2011). The cell abundances and species of sea ice diatoms decrease, whereas the dominance of green algae increases in the ice-covered area and at the ice–water interface (Macklin et al., 2002). The phytoplankton biomass in the Arctic Ocean has become higher than that on the shelves (Arrigo and van Dijken, 2015), accompanied by a shift in bloom dynamics (Ji et al., 2013). Ultimately, sea ice retreat in the Arctic Ocean is essential for the timing, quality, and quantity of primary production, which influences the standing stock of zooplankton and consequently the food web (Hunt et al., 2002, 2011).

    The size structure of phytoplankton is controlled by complex interactions among the marine physical mixing conditions, light environment, and nutrient concentrations (Li et al., 2009; Wassmann and Reigstad, 2011). According to cell volume, phytoplankton is usually classified into microplankton (>20 μm), nanoplankton (2–20 μm), and picoplankton (<2 μm) (Beardall et al., 2009). Of the three forms, microplankton is the more morphologically plastic and has a lower cell surface to volume ratio; however, picoplankton is dominant in marine planktonic ecosystems (Li et al., 2009), and it affects both energy flow and nutrient cycling in the Arctic Ocean (Mills et al., 2018). Small cells are mainly distributed in the oligotrophic and stratified ocean waters (Eppley and Peterson, 1979; Falkowski and Woodhead, 1992; Li et al., 2009). Variations in the size structure of the phytoplankton community and the species composition are essential for the migration of organic carbon to sediments because larger cells have a greater sinking rate and contribute to a highly efficient biological pump (Finkel et al., 2009). Therefore, it is important to understand the changes in phytoplankton community structure during the melting of sea ice (Sigman and Boyle, 2000).

    Owing to the influence of topography and sea ice, there are fewdata on chlorophyll(Chl) concentration in the high-latitude Arctic Ocean. Numerous earlier studies showed that the Chlconcentration exceeds 0.5 mg·m?3in the high-latitude Arctic Ocean (Cota et al., 1996; Coupel et al., 2015; Zhu et al., 2019; Kim et al., 2020). However, Lee and Whitledge (2005) reported that under-ice Chlconcentration was only 0.02 ± 0.01 mg·m?3in the surface layer. Moreover, most observations of size-fractionated Chlin the Arctic Ocean were conducted in shelf areas (e.g., the Barents and Chukchi seas) (Carmack and Wassmann, 2006), while few measurements were relevant to the high-latitude area (Poulin et al., 2010; Wassmann and Reigstad, 2011). Therefore, we investigated size-fractionated Chland related environmental parameters in the high-latitude Arctic Ocean (74°N–82°N; 160°E– 150°W) during the summer 2020 to determine the main factors affecting the phytoplankton distribution.

    2 Materials and methods

    2.1 Study sites and sampling locations

    In this study, we used a conductivity–temperature–depth profiler to obtain physical properties such as water temperature and salinity at 43 stations in the Arctic Ocean between July and August 2020 (Figure 1). Additionally, 1 L Niskin bottles were used to collect water samples from the surface to the depth of 200 m (seven different depths: 5, 30,50, 75, 100, 150, and 200 m) for size-fractionated Chland nutrient analyses. Sea ice concentration data were derived from the EUMETSAT OSI SAF product (https://osi-saf. eumetsat.int/products/sea-ice-products).

    Figure 1 Location of the sampling stations (red dots) in the Arctic Ocean during summer 2020. Blue solid lines represent transects P1, P2, P3, and R.

    2.2 Size-fractionated Chl a analysis

    The phytoplankton biomass was size-fractionated into micro- (20–200 μm), nano- (2–20 μm), and picoplankton (0.7–2.0 μm). First, water samples were filtered through 200 μm Nitex filters to remove zooplankton. The water samples (0.5–1.0 L) for size-fractionated Chlanalysis were sequentially filtered through 20 and 2 μm Nucleopore filters (25 mm in diameter) and 0.7 μm Whatman GF/F filters (25 mm in diameter). All samples were extracted with 90% acetone at ?20℃ for 24 h and measured using a fluorometer (10-AU; Turner Designs, San Jose, CA, USA), which was calibrated before the analysis was performed (Holm-Hansen et al., 1965; Welschmeyer, 1994).

    2.3 Chl a profile fitting

    The Chlprofile fitting was parameterized using the equation originally given in Lewis et al. (1983) but later modified by Platt and Sathyendranath (1988):

    whereis the normalized concentration of Chlat depth(mg·m?3),0is the background mixed-layer Chlconcentration (mg·m?3),is the integrated chlorophyll above0(mg·m?2),mis the depth of maximum chlorophyll (m), andis the standard deviation of the width of the Chlmaximum peak (m).mrepresents the maximum value of deep chlorophyll (mg·m?3).

    2.4 Nutrient analyses

    2.5 Data analysis

    The vertical distribution of Chlwas drawn using Ocean Data View (4.6.7). Multidimensional scaling (MDS) and cluster analysis were performed using PRIMER 6.0 to reveal the spatial patterns in sized-fractionated Chl. The Pearson correlation coefficient at the confidence level of< 0.05 was determined using R software (version 3.6).

    3 Results

    3.1 Hydrographic conditions and sea ice concentration

    Water temperature and salinity from the surface to the depth of 200 m in the Arctic Ocean are shown in Figure 2. Water temperature ranged from ?1.73℃ to 1.00℃ (mean= ?1.02±0.52℃), and salinity ranged from 26.5 to 34.7 (mean=31.6±2.18). The temperature–salinity relationships indicated the presence of certain water masses in the upper water column. According to both Gong and Pickart (2015) and Mills et al. (2018), water mass properties reflected mainly off-shelf meltwater (potential temperature ()?1℃ and>33.6), and Chukchi Summer Water (?1℃<<3℃ and 30<<33.6) (Figure 2a).

    Figure 2 Temperature–salinity (-) relationship of seawater (a) and sea ice concentration (b) at each station.

    The coverage of sea ice was relatively high because the investigation was conducted in the middle of the period of sea ice melting. The surface water temperature was ?1.21±0.19℃ and the salinity was 27.6±0.78. The northern part of the basin, called the “heavy-ice basin”, is where sea ice concentration was >70% and the surface water temperature was

    3.2 Distribution of Chl a

    The concentration of Chlvaried by two orders of magnitude throughout the study area, i.e., from 0.01– 2.68 mg·m?3(mean=0.05±0.18 mg·m?3). More than 80% of the Chlconcentration values in the water column (0–200 m) were <0.1 mg·m?3(Figure S1). The average surface Chlconcentration was 0.02±0.01 mg·m?3(Figure 3a). High values were found in the southern shelf zone and low values were found in the east of the Canada Basin. The subsurface chlorophyll maximum (SCM) was one order of magnitude higher than the surface Chlconcentration, with an average of 0.21 mg·m?3. In the water column, nearly 80% of the micro- and nano-Chlvalues were <0.01 mg·m?3, whereas nearly 40% of the pico-Chlvalues were >0.01 mg·m?3(Figure S1). The proportions of micro-, nano-, and picoplankton in the water column were 19%, 40%, and 41%, respectively (Figure S2b). However, the proportions of micro-, nano-, and picoplankton in the surface water were 17%, 28%, and 55%, respectively (Figure S2a). Micro-, nano-, and pico-Chlconcentrations in the surface water were >0.01 mg·m?3, and the distribution was more uniform in the southern shelf zone. However, the micro-Chlconcentration was extremely low in the east of the Canada Basin and at the stations north of 78°N, whereas the pico- Chlconcentration was >0.01 mg·m?3at stations north of 80°N.

    Figure 3 Distributions of total- (a), micro- (b), nano- (c), and pico-Chlconcentrations (d) in the surface layer.

    As shown in Figure 4, the average Chlconcentration was 6.60 ± 9.40 mg·m?2in the integrated water column (0–200 m). A high value (61.58 mg·m?2) occurred at station R2 on the southern shelf edge and a low value (2.00 mg·m?2) occurred at station P3-11 in the east of the Canada Basin. The percentage of microplankton in the water column was only 19%, while the percentage of nanoplankton and picoplankton was 41% and 40%, respectively (Figure S2b). Microplankton was overwhelmingly dominant at the southern shelf edge, whereas picoplankton was the main contributor in the east of the Canada Basin and the northern ice zone. Nanoplankton served as the main contributor only at station E2. The percentages of microplankton and nanoplankton were elevated in the subsurface layer. Although the Chlconcentration in the water column below 50 m was lower than that of the surface layer, the percentage of nanoplankton was 51%.

    3.3 Distribution of size-fractionated Chl a at transects P1, P2, P3, and R

    Figure 5 presents the vertical distributions of total-, micro-, nano-, and pico-Chlfrom the surface to the depth of 200 m at transects P1, P2, P3, and R. The total-Chlat stations P1-2 and P1-6 was 0.25 mg·m?3, and both were dominated by nanoplankton with a proportion of approximately 52% and 56%, respectively. Micro-Chlreached 0.1 mg·m?3at station P1-2, comprising 40% of the phytoplankton biomass. However, a high value of nano-Chloccurred at 60 m depth at station P1-2 and in the subsurface water at station P1-6. Picoplankton was the primary contributor at stations P1-7 and P1-8, comprising 64% and 79%, respectively.

    Figure 4 Total column-integrated Chlconcentration (0–200 m) at all stations (a), and the contributions of micro- (b), nano- (c), and pico-Chl(d) to the total-Chl(%) in the water column.

    The vertical distribution of Chlalong transect P2 indicated that the SCM was usually distributed in the upper 50 m of the water column. A high value (0.47 mg·m?3) was observed at station P2-2, primarily attributable to microplankton that comprised 64%. A low value (0.03 mg·m?3) was observed at station P2-10 in the east of the Canada Basin, which was contributed only by picoplankton. Additionally, picoplankton comprised approximately 67% at station P2-9 in the east of the Canada Basin (Figures 5b, 5f, 5j, 5n).

    The concentration of sea ice along transect P3 was usually >70% during the study period. There were no significant differences in the physicochemical properties of the water between stations. The vertical distribution of Chlwas relatively consistent from east to west. Extremely low values (<0.01 mg·m?3) appeared in the surface layer and reasonably high values (>0.05 mg·m?3) occurred in the subsurface layer. The highest Chlvalue (0.13 mg·m?3) was observed at stations P3-7 and P3-8, contributed primarily by picoplankton, which comprised 69% and 62%, respectively. However, the highest micro-Chlvalue (0.06 mg·m?3) was found only at station P3-12, located at 75-m depth. In contrast, micro-Chlwas <0.01 mg·m?3at other stations (Figures 5c, 5g, 5k, 5o).

    The vertical distribution of Chlalong transect R (Figures 5d, 5h, 5l, 5p) showed that the concentration of Chldecreased significantly, and extended northward from the Chukchi Sea shelf. The SCM generally occurred in the water column at depths <25 m. Additionally, the Chlconcentration decreased rapidly with increasing water depth at locations south of 76°N. In contrast, the SCM (~2 mg·m?3) at stations R1 and R2 was two orders of magnitude higher than that at the surface. These high values were contributed primarily by microplankton, which comprised >80%. The proportion of microplankton in the water column decreased rapidly at high latitudes. The concentration of Chlwas 0.19 mg·m?3at stations R7 and R8, of which 95% and 74%, respectively, was contributed by picoplankton.

    3.4 Chl a profile parameters

    The profile parameters of Chlcan provide a detailed characterization of phytoplankton vertical distribution. In the fitted equations of Lewis et al. (1983),mrepresents the maximum value of the deep Chl,mis the depth of the maximum concentration of Chlin the water column, andis a parameter that indicates the peak width. Figure 6 shows the vertical distribution of total-, micro-, nano-, and pico-Chl, and the Gaussian curve fitting parametersm,m, andfor all stations. A high value of total-Chlof 0.06 mg·m?3was found at station E1, where the proportion of nanoplankton was relatively high (50%). The total concentration of Chlwas 0.04 mg·m?3in the ice-covered area north of 82°N (station R9), which comprised 50% picoplankton. High values of Chl(0.03 mg·m?3) were found on the Chukchi Plateau, whereas low values (<0.01 mg·m?3) were observed in the east of the Canada Basin and along transect R.

    Figure 5 Vertical distributions of total-, micro-, nano-, and pico-Chlfrom the surface to the depth of 200 m at transect P1, P2, P3, and R. a–d, Total-Chldistribution along transect P1, transect P2, transect P3 and transect R, respectively; e–h, Micro-Chldistribution along transect P1, transect P2, transect P3 and transect R, respectively; i–l, Nano-Chldistribution along transect P1, transect P2, transect P3 and transect R, respectively; m–p, Pico-Chldistribution along transect P1, transect P2, transect P3 and transect R, respectively.

    Figure 6 Vertical distributions of total-, micro-, nano-, and pico-Chlconcentrations and the Gaussian curve parametersm,m, and. a–d, Total-, micro-, nano-, and pico-Chlconcentrations, respectively; e–h, Total-, micro-, nano-, and pico-mvalues, respectively; i–l, Total-, micro-, nano-, and pico-mvalues, respectively; m–p, Total-, micro-, nano-, and pico-values, respectively.

    Themvalues for total-, micro-, nano-, and picoplankton are presented in Figure 6e–6h, respectively. The total value ofmranged from 0.02–1.49 mg·m?3(mean= 0.19 mg·m?3). The highest value (1.49 mg·m?3) occurred at station E1 and consisted of Chl, while lower values (<0.15 mg·m–3) were found in the east of the Canada Basin and along transect R. The mean value of micro-mwas 0.13 mg·m?3, and the highest value (1.43 mg·m?3) was observed in the southern shelf area at station R1. Lower values occurred in the northern ice-covered area and on the eastern Chukchi Plateau. The nano-mvalues ranged from 0.01–0.61 mg·m?3(mean=0.07 mg·m?3). Low values occurred along transect P3, in the northern ice-covered area, and in the east of the Canada Basin, while high values were found in the southern shelf region. The average value of pico-mwas 0.07 mg·m?3, and high values appeared at stations P1-7 and P1-8. Overall, the mean value of micro-mwas significantly higher than that of either nano- or pico-m, andmwas higher in the southern shelf edge region.

    The meanmvalues of total-, micro-, nano-, and picoplankton were 39.78, 39.10, 41.09, and 37.76 m, respectively (Figure 6i–6l), and they were found in shallow water (<50 m). High values were found in the east of the Canada Basin. The total-, micro-, nano-, and pico-mvalues were 27.21, 25.73, 27.12, and 27.87 m, respectively, in the high-latitude area covered with sea ice (station R9). The surface water was dominated by picoplankton, and high values were found in the high-latitude ice-covered area, along transect P3, and in the east of the Canada Basin.

    The parameterindicates the peak width of Chl. Thevalues of total-, micro-, nano-, and picoplankton are shown in Figure 6m–6p, respectively. The meanvalues for total-, micro-, nano-, and picoplankton were 13.29, 12.41, 12.29, and 12.85 m, respectively. Relatively high values were present in the high-latitude ice-covered area, along transect P3, and in the east of the Canada Basin. However, nano-σ (<10 m) decreased significantly in the southern shelf area.

    3.5 Sized-fractionated Chl a clustering analysis and MDS

    Figure 7 Cluster analysis (a) and MDS (b) of micro-, nano-, and picoplankton column-integrated chlorophyll (0–200 m) at all stations. Red indicates first assemblage, blue indicates second assemblage, and green indicates third assemblage.

    Table 1 Concentration of size-fractionated Chl a (mean±SD) and environmental parameters of the different ecological assemblages in the water column

    4 Discussion

    4.1 Chl a dynamics

    The distribution of Chlin the high-latitude Arctic Ocean is significantly influenced by topography and sea ice. Topography controls the circulation (Ryan et al., 2010), while sea ice primarily controls the light in the oligotrophic surface waters (Kwok and Rothrock, 2009). An extremely low phytoplankton biomass (mean=0.05± 0.18 mg·m?3) was found in this study, and more than 80% of Chlconcentration values were <0.1 mg·m?3. These findings are highly consistent with previous related studies, where the mean phytoplankton biomass in surface waters was only 0.04±0.02 mg·m?3in ice-free areas and even lower (0.02±0.01 mg·m?3) in ice-covered areas (Lee and Whitledge, 2005). However, numerous studies found that phytoplankton Chlconcentration exceeds 0.5 mg·m?3in the high-latitude Arctic Ocean (Table 2). Arrigo et al. (2014) found that the surface Chlconcentration reached 2.5 mg·m?3in the northern Chukchi Sea, because the phytoplankton had experienced a two-week ice-free period. In this study, fewer than 10% of the Chlconcentration values were >0.5 mg·m?3. The extremely low phytoplankton biomass could reflect the fact that the study cruise was conducted in the middle of the ice-melting period, when the concentration of sea ice was >70% at most stations.

    4.2 Relationship between phytoplankton cluster and water mass

    Table 2 Surface Chl a concentration in the high-latitude area of the Arctic Ocean

    The coastal Cluster 3 was affected by Chukchi Summer Water (Gong and Pickart, 2015), where microplankton contributed more than 90% of total Chl. Coupel et al. (2012) found that large cells, such as diatoms and dinoflagellates, dominate in the Bering Strait and on the Chukchi shelf where the concentration of sea ice is extremely low. The value ofmwas significantly higher in the southern shelf area (station E1), but the correspondingmvalue was located at the depth of 30 m. One possible reason that could account for this phenomenon is the low sea ice concentration (27.6%) at station E1. Another reason could be the shallow water depth in the area and the ease of nutrient replenishment, which could provide opportunities for diatom blooms in specific and more stable water layers (Codispoti et al., 2013). Additionally, the availability of nutrients is often the primary factor that influences phytoplankton size structure (Mara?ón et al., 2015). We found that micro-m(0.13 mg·m?3) was significantly higher than nano- (0.07 mg·m?3) and pico-m(0.07 mg·m?3), possibly owing to the rapid settlement of microplankton (e.g., diatoms). When nutrients are depleted, microplankton is more likely to form deep chlorophyll maximum layers (Codispoti et al., 2013).

    In summary, the contribution of both nano- (41%) and picoplankton (40%) in the water column was significantly higher than that of microplankton (19%), indicating significant miniaturization of the community structure (Figure S2). Due to decreasing in the nutrient supply and low availability of light, the surface phytoplankton biomass was relatively low and dominated primarily by picoplankton in the Arctic Ocean (McLaughlin and Carmack, 2010). These findings are highly consistent with numerous other studies that indicated that picoplankton could adapt more effectively to low-nutrient environments in ice-covered areas (Lovejoy et al., 2006, 2007; Li et al., 2009; Coupel et al., 2015; Mills et al., 2018). The averagemandvalues were 39.42 and 12.71 m, respectively, implying that the range of phytoplankton distribution was extremely limited. Possible reasons for the variability in the vertical distribution ofminclude differences in losses to predators, growth, and sinking or migration among the different phytoplankton groups (Cullen, 2015).

    5 Conclusions

    Our study showed that the phytoplankton biomass was extremely low in the high-latitude Arctic Ocean during the summer 2020. Relatively high Chlconcentrations were found in the eastern part of the Chukchi Plateau, where the sea ice concentration was <20% and the supplement of nutrients increased. Picoplankton dominated the phytoplankton community, indicating that the efficiency of the biological pump was substantially reduced, and that the carbon cycle was necessarily dominated by physical processes. The Chlprofile analysis showed that the vertical distribution ofmwas relatively stable, and that the sized-fractionatedmwas located at the depth of approximately 40 m. It implies that phytoplankton productivity was limited by nutrients rather than by light. According to the cluster analysis, the under-ice phytoplankton distribution was coupled with water masses because the mixing conditions cause nutrients distributions to vary. These results contribute to our understanding of the biogeochemical features of the high-latitude Arctic Ocean during the period of sea ice melting.

    Q. H. designed this study. Y. B., M. L., J. H., and J. C. performed the experiments and analysis. T. C. wrote the manuscript and prepared the tables and figures. All authors edited the manuscript. All authors have read and agreed to the published version of the manuscript. T. C. and Q. H. contributed equally to this work and both should be considered co-first author.

    The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

    We would like to thank the captain, officers, and crew of R/Vfor their admirable assistance during the onboard sampling and measurements conducted as part of the study. This research was supported by the National Key R&D Program of China (Grant no. 2019YFE0120900) and the National Natural Science Foundation of China (Grant nos. 41941013, 41976230, 41206181, and 41976229). We appreciate two anonymous reviewers, and Associate Editor Dr. Jana Kvíderová for their constructive comments that have further improved the manuscript.

    Arrigo K R, Perovich D K, Pickart R S, et al. 2014. Phytoplankton blooms beneath the sea ice in the Chukchi Sea. Deep Sea Res Part II Top Stud Oceanogr, 105: 1-16, doi:10.1016/j.dsr2.2014.03.018.

    Arrigo K R, van Dijken G L. 2004. Annual cycles of sea ice and phytoplankton in Cape Bathurst polynya, southeastern Beaufort Sea, Canadian Arctic. Geophys Res Lett, 31(8): L08304, doi:10.1029/2003 gl018978.

    Arrigo K R, van Dijken G L. 2015. Continued increases in Arctic Ocean primary production. Prog Oceanogr, 136: 60-70, doi:10.1016/j.pocean. 2015.05.002.

    Beardall J, Allen D, Bragg J, et al. 2009. Allometry and stoichiometry of unicellular, colonial and multicellular phytoplankton. New Phytol, 181(2): 295-309, doi:10.1111/j.1469-8137.2008.02660.x.

    Carmack E, Wassmann P. 2006. Food webs and physical-biological coupling on pan-Arctic shelves: Unifying concepts and comprehensive perspectives. Prog Oceanogr, 71: 446-477, doi:10.1016/j.pocean.2006. 10.004.

    Churnside J H, Marchbanks R D, Marshall N. 2021. Airborne lidar observations of a spring phytoplankton bloom in the western Arctic Ocean. Remote Sens, 13(13): 2512, doi:10.3390/rs13132512.

    Codispoti L A, Kelly V, Thessen A, et al. 2013. Synthesis of primary production in the Arctic Ocean: III. Nitrate and phosphate based estimates of net community production. Prog Oceanogr, 110: 126-150, doi:10.1016/j.pocean.2012.11.006.

    Cota G F, Pomeroy L R, Harrison W G, et al. 1996. Nutrients, primary production and microbial heterotrophy in the southeastern Chukchi Sea: Arctic summer nutrient depletion and heterotrophy. Mar Ecol Prog Ser, 135: 247-258, doi:10.3354/meps135247.

    Coupel P, Jin H Y, Joo M, et al. 2012. Phytoplankton distribution in unusually low sea ice cover over the Pacific Arctic. Biogeosciences, 9(11): 4835-4850, doi:10.5194/bg-9-4835-2012.

    Coupel P, Ruiz-Pino D, Sicre M A, et al. 2015. The impact of freshening on phytoplankton production in the Pacific Arctic Ocean. Prog Oceanogr, 131: 113-125, doi:10.1016/j.pocean.2014.12.003.

    Cullen J J. 2015. Subsurface chlorophyll maximum layers: enduring enigma or mystery solved? Ann Rev Mar Sci, 7: 207-239, doi:10.1146/annurev-marine-010213-135111.

    Eicken H. 2002. Tracer studies of pathways and rates of meltwater transport through Arctic summer sea ice. J Geophys Res, 107(C10): 8046, doi:10.1029/2000jc000583.

    Eppley R W, Peterson B J. 1979. Particulate organic matter flux and planktonic new production in the deep ocean. Nature, 282(5740): 677-680, doi:10.1038/282677a0.

    Falkowski P G, Woodhead A D, Vivirito K. 1992. Primary productivity and biogeochemical cycles in the sea. Boston: Springer US, doi:10.1007/978-1-4899-0762-2.

    Finkel Z V, Beardall J, Flynn K J, et al. 2009. Phytoplankton in a changing world: cell size and elemental stoichiometry. J Plankton Res, 32(1): 119-137, doi:10.1093/plankt/fbp098.

    Gong D L, Pickart R S. 2015. Summertime circulation in the eastern Chukchi Sea. Deep Sea Res Part II Top Stud Oceanogr, 118: 18-31, doi:10.1016/j.dsr2.2015.02.006.

    Gosselin M, Levasseur M, Wheeler P A, et al. 1997. New measurements of phytoplankton and ice algal production in the Arctic Ocean. Deep Sea Res Part II Top Stud Oceanogr, 44(8): 1623-1644, doi:10.1016/ S0967-0645(97)00054-4.

    Holm-Hansen O, Lorenzen C J, Holmes R W, et al. 1965. Fluorometric determination of chlorophyll. ICES J Mar Sci, 30(1): 3-15, doi:10.1093/icesjms/30.1.3.

    Hunt G L, Stabeno P, Walters G, et al. 2002. Climate change and control of the southeastern Bering Sea pelagic ecosystem. Deep Sea Res Part II Top Stud Oceanogr, 49(26): 5821-5853, doi:10.1016/S0967- 0645(02)00321-1.

    Hunt G L, Coyle K O, Eisner L B, et al. 2011. Climate impacts on eastern Bering Sea foodwebs: a synthesis of new data and an assessment of the Oscillating Control Hypothesis. ICES J Mar Sci, 68(6): 1230-1243, doi:10.1093/icesjms/fsr036.

    Ji R, Jin M, Varpe ?. 2013. Sea ice phenology and timing of primary production pulses in the Arctic Ocean. Glob Change Biol, 19(3): 734-741, doi:10.1111/gcb.12074.

    Kim B, Jung J, Lee Y, et al. 2020. Characteristics of the biochemical composition and bioavailability of phytoplankton-derived particulate organic matter in the Chukchi Sea, Arctic. Water, 12(9): 2355, doi:10.3390/w12092355.

    Kim B K, Lee J H, Yun M S, et al. 2015. High lipid composition of particulate organic matter in the northern Chukchi Sea, 2011. Deep Sea Res Part II Top Stud Oceanogr, 120: 72-81, doi:10.1016/j.dsr2. 2014.03.022.

    Kwok R, Rothrock D A. 2009. Decline in Arctic sea ice thickness from submarine and ICESat records: 1958-2008. Geophys Res Lett, 36(15): L15501, doi:10.1029/2009gl039035.

    Latasa M, Cabello A M, Morán X A G, et al. 2017. Distribution of phytoplankton groups within the deep chlorophyll maximum. Limnol Oceanogr, 62(2): 665-685, doi:10.1002/lno.10452.

    Lee S H, Whitledge T E. 2005. Primary and new production in the deep Canada Basin during summer 2002. Polar Biol, 28(3): 190-197, doi:10.1007/s00300-004-0676-3.

    Leu E, S?reide J E, Hessen D O, et al. 2011. Consequences of changing sea-ice cover for primary and secondary producers in the European Arctic shelf seas: timing, quantity, and quality. Prog Oceanogr, 90(1-4): 18-32, doi:10.1016/j.pocean.2011.02.004.

    Lewis M R, Cullen J J, Platt T. 1983. Phytoplankton and thermal structure in the upper ocean: consequences of nonuniformity in chlorophyll profile. J Geophys Res, 88(C4): 2565, doi:10.1029/ jc088ic04p02565.

    Li W K W, McLaughlin F A, Lovejoy C, et al. 2009. Smallest algae thrive as the Arctic Ocean freshens. Science, 326(5952): 539, doi:10.1126/science.1179798.

    Lovejoy C, Massana R, Pedrós-Alió C. 2006. Diversity and distribution of marine microbial eukaryotes in the Arctic Ocean and adjacent seas. Appl Environ Microbiol, 72(5): 3085-3095, doi:10.1128/AEM.72.5. 3085-3095.2006.

    Lovejoy C, Vincent W F, Bonilla S, et al. 2007. Distribution, phylogeny, and growth of cold-adapted Picoprasinophytes in Arctic seas. J Phycol, 43(1): 78-89, doi:10.1111/j.1529-8817.2006.00310.x.

    Macklin S A, Hunt G L, Overland J E. 2002. Collaborative research on the pelagic ecosystem of the southeastern Bering Sea shelf. Deep Sea Res Part II Top Stud Oceanogr, 49(26): 5813-5819, doi:10.1016/S 0967-0645(02)00320-X.

    Mara?ón E, Cerme?o P, Latasa M, et al. 2015. Resource supply alone explains the variability of marine phytoplankton size structure. Limnol Oceanogr, 60(5): 1848-1854, doi:10.1002/lno.10138.

    McLaughlin F A, Carmack E C. 2010. Deepening of the nutricline and chlorophyll maximum in the Canada Basin interior, 2003-2009. Geophys Res Lett, 37(24): L24602, doi:10.1029/2010gl045459.

    Mills M M, Brown Z W, Laney S R, et al. 2018. Nitrogen limitation of the summer phytoplankton and heterotrophic prokaryote communities in the Chukchi Sea. Front Mar Sci, 5: 362, doi:10.3389/fmars.2018. 00362.

    Mundy C J, Barber D G, Michel C. 2005. Variability of snow and ice thermal, physical and optical properties pertinent to sea ice algae biomass during spring. J Mar Syst, 58(3-4): 107-120, doi:10.1016/j. jmarsys.2005.07.003.

    Pabi S, van Dijken G L, Arrigo K R. 2008. Primary production in the Arctic Ocean, 1998-2006. J Geophys Res, 113(C8): C08005, doi:10.1029/2007jc004578.

    Perovich D K, Richter-Menge J A. 2009. Loss of sea ice in the Arctic. Ann Rev Mar Sci, 1: 417-441, doi:10.1146/annurev.marine.010908.163805.

    Platt T, Sathyendranath S. 1988. Oceanic primary production: estimation by remote sensing at local and regional scales. Science, 241(4873): 1613-1620, doi:10.1126/science.241.4873.1613.

    Poulin M, Daugbjerg N, Gradinger R, et al. 2010. The pan-Arctic biodiversity of marine pelagic and sea-ice unicellular eukaryotes: a first-attempt assessment. Mar Biodiv, 41(1): 13-28, doi:10.1007/s 12526-010-0058-8.

    Redfield A C, Ketchum B H, Richards F A. 1963. The influence of organisms on the composition of the sea water//Hill M N. The Sea,Vol. 2, New York: Interscience Publishers, 26-77.

    Ryan J P, McManus M A, Sullivan J M. 2010. Interacting physical, chemical and biological forcing of phytoplankton thin-layer variability in Monterey Bay, California. Cont Shelf Res, 30(1): 7-16, doi:10.1016/j.csr.2009.10.017.

    Sigman D M, Boyle E A. 2000. Glacial/interglacial variations in atmospheric carbon dioxide. Nature, 407(6806): 859-869, doi:10. 1038/35038000.

    Soltwedel T, Bauerfeind E, Bergmann M, et al. 2005. HAUSGARTEN: multidisciplinary investigations at a deep-sea, long-term observatory in the Arctic Ocean. Oceanography, 18(3): 46-61, doi:10.5670/ oceanog.2005.24.

    Soltwedel T, Bauerfeind E, Bergmann M, et al. 2016. Natural variability or anthropogenically-induced variation? Insights from 15 years of multidisciplinary observations at the Arctic marine LTER site HAUSGARTEN. Ecol Indic, 65: 89-102, doi:10.1016/j.ecolind. 2015.10.001.

    Steele M, Ermold W, Zhang J. 2008. Arctic Ocean surface warming trends over the past 100 years. Geophys Res Lett, 35(2): L02614, doi:10.1029/2007gl031651.

    Wang J, Cota G F, Comiso J C. 2005. Phytoplankton in the Beaufort and Chukchi Seas: distribution, dynamics, and environmental forcing. Deep Sea Res Part II Top Stud Oceanogr, 52(24-26): 3355-3368, doi:10.1016/j.dsr2.2005.10.014.

    Wassmann P, Reigstad M. 2011. Future Arctic Ocean seasonal ice zones and implications for pelagic-benthic coupling. Oceanography, 24(3): 220-231, doi:10.5670/oceanog.2011.74.

    Welschmeyer N A. 1994. Fluorometric analysis of chlorophyllin the presence of chlorophylland pheopigments. Limnol Oceanogr, 39(8): 1985-1992, doi:10.4319/lo.1994.39.8.1985.

    Yun M S, Joo H M, Kang J J, et al. 2019. Potential implications of changing photosynthetic end-products of phytoplankton caused by sea ice conditions in the northern Chukchi Sea. Front Microbiol, 10: 2274, doi:10.3389/fmicb.2019.02274.

    Yun M S, Lee D B, Kim B K, et al. 2015. Comparison of phytoplankton macromolecular compositions and zooplankton proximate compositions in the northern Chukchi Sea. Deep Sea Res Part II Top Stud Oceanogr, 120: 82-90, doi:10.1016/j.dsr2.2014.05.018.

    Zhu Y, Suggett D, Liu C, et al. 2019. Primary productivity dynamics in the summer Arctic Ocean confirms broad regulation of the electron requirement for carbon fixation by light-phytoplankton community interaction. Front Mar Sci, 6: 167218194, doi:10.3389/fmars.2019. 00275.

    Figure S1 The frequency of the total- (a), micro- (b), nano- (c) and pico-Chlconcentrations (d) in the Arctic Ocean.

    Figure S2 The compositions of size-fractionated Chlin the surface (a) and in the water column (b) in the study area.

    Figure S3 Pearson’s Correlation Coefficient between biological variables and environmental parameters in the water column (0–200 m) in the Arctic Ocean (total-, micro-, nano- and pico-Chlhas taken logarithm; * represent< 0.05, ** represent< 0.01 and *** represent< 0.001).

    Figure S4 The vertical distributions of nitrate, phosphate and silicate from the surface to a depth of 200 m at transect P1, P2, P3, R.

    10.13679/j.advps.2021.0056

    10 December 2021;

    10 June 2022;

    30 August 2022

    : Cai T, Hao Q, Bai Y C, et al. Variability of size-fractionated chlorophyllin the high-latitude Arctic Ocean in summer 2020. Adv Polar Sci, 2022, 33(3): 253-266,doi:10.13679/j.advps.2021.0056

    , ORCID: 0000-0003-2145-2703, E-mail: haoq@sio.org.cn

    日韩制服骚丝袜av| 少妇高潮的动态图| 免费黄色在线免费观看| 少妇被粗大猛烈的视频| 久久久欧美国产精品| 精品亚洲乱码少妇综合久久| 熟女人妻精品中文字幕| 春色校园在线视频观看| 少妇猛男粗大的猛烈进出视频| 国产国拍精品亚洲av在线观看| 日日啪夜夜撸| 美女脱内裤让男人舔精品视频| 亚洲色图av天堂| 久久精品熟女亚洲av麻豆精品| 国产成人a∨麻豆精品| 欧美一区二区亚洲| 777米奇影视久久| 国产黄频视频在线观看| 国产精品一区二区性色av| 国产极品天堂在线| 日韩人妻高清精品专区| 另类亚洲欧美激情| 老女人水多毛片| 免费在线观看成人毛片| 亚洲精品国产成人久久av| 亚洲欧美成人综合另类久久久| 亚洲电影在线观看av| 国产伦理片在线播放av一区| 久久久a久久爽久久v久久| 韩国高清视频一区二区三区| 久久午夜福利片| 亚洲精品国产色婷婷电影| 精品久久久久久电影网| 亚洲精品,欧美精品| 熟女电影av网| 成人午夜精彩视频在线观看| 国产一级毛片在线| 亚洲精品乱码久久久v下载方式| 91精品国产国语对白视频| 丰满乱子伦码专区| 成人国产av品久久久| 免费av中文字幕在线| 少妇丰满av| 国产精品国产三级专区第一集| 男女边摸边吃奶| 1000部很黄的大片| 国产有黄有色有爽视频| 成人免费观看视频高清| 久久精品国产亚洲av涩爱| 久久久久久久大尺度免费视频| 国模一区二区三区四区视频| 亚洲国产欧美人成| 国产成人91sexporn| 国产免费一级a男人的天堂| 欧美+日韩+精品| 欧美成人午夜免费资源| 欧美成人精品欧美一级黄| 精品人妻熟女av久视频| a级毛色黄片| 中文字幕亚洲精品专区| 亚洲精品一区蜜桃| 亚洲国产精品国产精品| 丝瓜视频免费看黄片| 久久久久久久大尺度免费视频| 国产无遮挡羞羞视频在线观看| 天堂俺去俺来也www色官网| 成年免费大片在线观看| av女优亚洲男人天堂| 国产v大片淫在线免费观看| 91精品国产九色| 丝袜喷水一区| 国产日韩欧美亚洲二区| 亚洲av综合色区一区| 国产美女午夜福利| 婷婷色综合www| 99久国产av精品国产电影| 色婷婷久久久亚洲欧美| 久久国内精品自在自线图片| 啦啦啦视频在线资源免费观看| 色视频在线一区二区三区| 99九九线精品视频在线观看视频| 色吧在线观看| 国产精品av视频在线免费观看| 色网站视频免费| 岛国毛片在线播放| 亚洲久久久国产精品| 日韩国内少妇激情av| 久久鲁丝午夜福利片| 看十八女毛片水多多多| 女性生殖器流出的白浆| 国产又色又爽无遮挡免| av专区在线播放| 久久久久久久亚洲中文字幕| 亚洲国产精品国产精品| 国产中年淑女户外野战色| 男人和女人高潮做爰伦理| 国模一区二区三区四区视频| 六月丁香七月| 国产成人免费无遮挡视频| 国产精品精品国产色婷婷| 一级片'在线观看视频| 亚洲av男天堂| 婷婷色综合大香蕉| 亚洲欧美日韩无卡精品| 欧美精品人与动牲交sv欧美| 中文欧美无线码| 日韩精品有码人妻一区| 精品久久久久久久久亚洲| 亚洲天堂av无毛| 在线观看免费日韩欧美大片 | 高清日韩中文字幕在线| 丰满人妻一区二区三区视频av| 久久久久久久久久人人人人人人| 亚洲国产日韩一区二区| 久久亚洲国产成人精品v| 国产欧美日韩精品一区二区| 欧美日本视频| 中文资源天堂在线| 日本欧美视频一区| 99热这里只有是精品50| 18+在线观看网站| 国产成人午夜福利电影在线观看| 亚洲无线观看免费| 日韩电影二区| 欧美+日韩+精品| 肉色欧美久久久久久久蜜桃| 亚洲激情五月婷婷啪啪| freevideosex欧美| freevideosex欧美| av免费观看日本| 精品国产乱码久久久久久小说| 在线观看三级黄色| 又粗又硬又长又爽又黄的视频| 黑人猛操日本美女一级片| 午夜免费鲁丝| 国精品久久久久久国模美| 亚洲精品国产色婷婷电影| av一本久久久久| 一级二级三级毛片免费看| 免费观看无遮挡的男女| 2021少妇久久久久久久久久久| 精品亚洲成国产av| 国产在线视频一区二区| 2022亚洲国产成人精品| 久久久精品94久久精品| 国产精品熟女久久久久浪| 国产亚洲精品久久久com| 久久韩国三级中文字幕| 大香蕉97超碰在线| 久久久久久久大尺度免费视频| tube8黄色片| 国产欧美亚洲国产| 男的添女的下面高潮视频| 日本色播在线视频| 高清日韩中文字幕在线| 一本色道久久久久久精品综合| 男女边吃奶边做爰视频| 一级毛片电影观看| 一区二区三区四区激情视频| 精品一区在线观看国产| 少妇裸体淫交视频免费看高清| 最后的刺客免费高清国语| 熟女人妻精品中文字幕| 欧美成人精品欧美一级黄| 精品久久久噜噜| 久久久欧美国产精品| 国产伦理片在线播放av一区| 伊人久久精品亚洲午夜| 性高湖久久久久久久久免费观看| 亚洲欧美一区二区三区黑人 | 日日摸夜夜添夜夜爱| av国产精品久久久久影院| 少妇猛男粗大的猛烈进出视频| 国产中年淑女户外野战色| a级一级毛片免费在线观看| 如何舔出高潮| 久久久久久久亚洲中文字幕| 欧美日本视频| 边亲边吃奶的免费视频| 免费人妻精品一区二区三区视频| 我的女老师完整版在线观看| 久久ye,这里只有精品| 大片免费播放器 马上看| 国产精品久久久久久精品电影小说 | av免费观看日本| 免费播放大片免费观看视频在线观看| 九九久久精品国产亚洲av麻豆| 我的女老师完整版在线观看| 自拍欧美九色日韩亚洲蝌蚪91 | 色综合色国产| 精品一区二区三卡| 亚洲无线观看免费| 一个人看的www免费观看视频| 午夜福利网站1000一区二区三区| 大陆偷拍与自拍| av在线蜜桃| 国产精品无大码| 日韩三级伦理在线观看| 丰满迷人的少妇在线观看| 日韩欧美精品免费久久| 毛片一级片免费看久久久久| 最后的刺客免费高清国语| 成年人午夜在线观看视频| 国产精品国产三级国产专区5o| 久久久久久久国产电影| 久久精品国产a三级三级三级| 日日啪夜夜爽| 国产日韩欧美亚洲二区| 久久久久久久亚洲中文字幕| 久热这里只有精品99| 岛国毛片在线播放| 国产黄频视频在线观看| 亚洲精品色激情综合| 日韩三级伦理在线观看| 伦理电影免费视频| 久久久色成人| 国产v大片淫在线免费观看| 精品一区二区三卡| 99视频精品全部免费 在线| 亚洲欧美日韩无卡精品| 菩萨蛮人人尽说江南好唐韦庄| 少妇的逼好多水| 能在线免费看毛片的网站| 青春草国产在线视频| 国产成人精品一,二区| 人妻一区二区av| 三级经典国产精品| 久久精品久久久久久噜噜老黄| 舔av片在线| a级毛色黄片| 久久婷婷青草| 天堂中文最新版在线下载| 自拍偷自拍亚洲精品老妇| 最新中文字幕久久久久| 黄色怎么调成土黄色| 三级国产精品片| 丝袜喷水一区| 久久女婷五月综合色啪小说| 欧美精品一区二区大全| 又大又黄又爽视频免费| 国产精品一区二区在线不卡| 午夜老司机福利剧场| 亚洲人成网站在线播| 国产日韩欧美在线精品| 久久国产精品男人的天堂亚洲 | 尤物成人国产欧美一区二区三区| 人人妻人人看人人澡| 成人亚洲精品一区在线观看 | 亚洲欧美成人综合另类久久久| 国产亚洲91精品色在线| 91精品国产国语对白视频| a 毛片基地| 老熟女久久久| 大又大粗又爽又黄少妇毛片口| www.av在线官网国产| 三级国产精品欧美在线观看| 26uuu在线亚洲综合色| 国产精品三级大全| 国产免费视频播放在线视频| 丝袜脚勾引网站| 又爽又黄a免费视频| 麻豆成人av视频| 1000部很黄的大片| 亚洲怡红院男人天堂| 久久久久人妻精品一区果冻| 午夜福利影视在线免费观看| 国产精品久久久久久精品古装| 精品一区二区三卡| av天堂中文字幕网| 欧美日韩在线观看h| 亚洲自偷自拍三级| 亚洲色图综合在线观看| 国产一级毛片在线| 人人妻人人看人人澡| 成人毛片a级毛片在线播放| 十分钟在线观看高清视频www | 亚洲精品日韩av片在线观看| 爱豆传媒免费全集在线观看| 99久久综合免费| 一级av片app| 亚洲丝袜综合中文字幕| av网站免费在线观看视频| 精品午夜福利在线看| 91精品伊人久久大香线蕉| 干丝袜人妻中文字幕| h视频一区二区三区| 身体一侧抽搐| 亚洲精品乱久久久久久| 最后的刺客免费高清国语| av黄色大香蕉| 一级毛片黄色毛片免费观看视频| 99热国产这里只有精品6| 欧美一区二区亚洲| 久久久久性生活片| 青春草视频在线免费观看| 在线天堂最新版资源| 日本wwww免费看| 少妇猛男粗大的猛烈进出视频| 超碰97精品在线观看| 午夜视频国产福利| 欧美区成人在线视频| 国内揄拍国产精品人妻在线| 亚洲欧洲日产国产| 日韩 亚洲 欧美在线| 中文在线观看免费www的网站| 亚洲最大成人中文| 最黄视频免费看| 一区二区三区四区激情视频| 国产精品伦人一区二区| 国产毛片在线视频| 最黄视频免费看| 亚洲精品国产成人久久av| 最近2019中文字幕mv第一页| 黄色欧美视频在线观看| 亚洲av欧美aⅴ国产| 欧美精品国产亚洲| 欧美成人a在线观看| 天堂俺去俺来也www色官网| 中国美白少妇内射xxxbb| 深夜a级毛片| 啦啦啦视频在线资源免费观看| 香蕉精品网在线| 蜜桃在线观看..| 我的老师免费观看完整版| 男女下面进入的视频免费午夜| 精品少妇久久久久久888优播| 熟妇人妻不卡中文字幕| 国产男女超爽视频在线观看| 亚洲欧洲国产日韩| 免费观看无遮挡的男女| 亚洲精品国产av蜜桃| 亚洲欧美中文字幕日韩二区| 美女中出高潮动态图| 亚洲精品视频女| 国产高清国产精品国产三级 | 全区人妻精品视频| 九色成人免费人妻av| 欧美xxxx性猛交bbbb| 午夜免费观看性视频| 91午夜精品亚洲一区二区三区| 欧美少妇被猛烈插入视频| 亚洲欧美一区二区三区国产| 成人一区二区视频在线观看| 国产免费福利视频在线观看| 亚洲精品乱久久久久久| 春色校园在线视频观看| 新久久久久国产一级毛片| 国产高清不卡午夜福利| 精品久久久久久电影网| 在线观看免费高清a一片| 久久久久久久国产电影| 女性生殖器流出的白浆| 少妇丰满av| 亚洲aⅴ乱码一区二区在线播放| 91精品国产九色| 国产探花极品一区二区| 一区在线观看完整版| 久久青草综合色| 中文字幕制服av| 亚洲色图av天堂| 亚洲欧美成人综合另类久久久| 啦啦啦视频在线资源免费观看| 亚洲精品国产av蜜桃| 精品酒店卫生间| 国产精品av视频在线免费观看| 91精品伊人久久大香线蕉| 免费黄网站久久成人精品| 黄色配什么色好看| 男女下面进入的视频免费午夜| av卡一久久| 国产深夜福利视频在线观看| 久久人妻熟女aⅴ| 欧美少妇被猛烈插入视频| 简卡轻食公司| 午夜免费男女啪啪视频观看| 一区二区三区精品91| 国产黄片视频在线免费观看| 国产亚洲av片在线观看秒播厂| 欧美精品人与动牲交sv欧美| 我要看日韩黄色一级片| 久热久热在线精品观看| 久久久久久久久久久免费av| 色吧在线观看| 少妇 在线观看| 久久久久国产网址| 精品午夜福利在线看| 国产精品一二三区在线看| 人妻一区二区av| 少妇人妻久久综合中文| 久久久久网色| 一个人看视频在线观看www免费| www.色视频.com| 女性被躁到高潮视频| 久久久久久久久久成人| 国产一区二区在线观看日韩| 成人无遮挡网站| 国产欧美日韩精品一区二区| 日本午夜av视频| 国产精品久久久久久精品电影小说 | 中文资源天堂在线| 男女下面进入的视频免费午夜| 日韩欧美精品免费久久| 亚洲av成人精品一区久久| 男女边摸边吃奶| 国产高清有码在线观看视频| 国产色婷婷99| av国产免费在线观看| av国产久精品久网站免费入址| 日日啪夜夜爽| 天天躁夜夜躁狠狠久久av| 国产精品久久久久久av不卡| 精品视频人人做人人爽| 国产一区二区在线观看日韩| 久久国内精品自在自线图片| 赤兔流量卡办理| 99热国产这里只有精品6| 人妻少妇偷人精品九色| 不卡视频在线观看欧美| 久久久久久伊人网av| 欧美xxxx性猛交bbbb| 亚洲欧美日韩东京热| 精品午夜福利在线看| 久久久久性生活片| 久久久久久久久久久免费av| 亚洲av福利一区| 亚洲精品国产av蜜桃| 欧美区成人在线视频| 美女xxoo啪啪120秒动态图| 国产日韩欧美亚洲二区| 免费人妻精品一区二区三区视频| 毛片女人毛片| 99精国产麻豆久久婷婷| 久久综合国产亚洲精品| 高清毛片免费看| 高清午夜精品一区二区三区| 午夜激情久久久久久久| 亚洲国产成人一精品久久久| 久久av网站| 国产精品一区二区性色av| 免费av中文字幕在线| 春色校园在线视频观看| av在线app专区| 日韩av不卡免费在线播放| 亚洲aⅴ乱码一区二区在线播放| 国产一区有黄有色的免费视频| 国产爱豆传媒在线观看| 91久久精品国产一区二区成人| 国产成人a区在线观看| 国内少妇人妻偷人精品xxx网站| 黑人猛操日本美女一级片| 超碰97精品在线观看| 你懂的网址亚洲精品在线观看| 麻豆国产97在线/欧美| 亚洲av综合色区一区| 插逼视频在线观看| 欧美少妇被猛烈插入视频| 韩国高清视频一区二区三区| 亚洲欧美日韩东京热| 十分钟在线观看高清视频www | 久久精品国产鲁丝片午夜精品| 大又大粗又爽又黄少妇毛片口| 婷婷色麻豆天堂久久| 免费大片18禁| 欧美丝袜亚洲另类| 在线天堂最新版资源| 午夜福利视频精品| 日韩一区二区视频免费看| 欧美bdsm另类| 欧美xxxx性猛交bbbb| 日本黄大片高清| 国产精品国产三级国产av玫瑰| 大香蕉97超碰在线| 日韩欧美一区视频在线观看 | 蜜桃在线观看..| 高清日韩中文字幕在线| 日本av免费视频播放| 岛国毛片在线播放| 亚洲内射少妇av| 亚洲人成网站在线播| 国产精品一区二区性色av| 国产精品女同一区二区软件| av线在线观看网站| 男人舔奶头视频| 天美传媒精品一区二区| 九九爱精品视频在线观看| 黄色日韩在线| 国产亚洲最大av| 亚洲精品乱码久久久v下载方式| 亚洲国产高清在线一区二区三| 在线观看国产h片| 精品亚洲成国产av| 精华霜和精华液先用哪个| 欧美xxxx性猛交bbbb| 三级国产精品欧美在线观看| 欧美日韩国产mv在线观看视频 | 亚洲天堂av无毛| a 毛片基地| 国产有黄有色有爽视频| 日韩成人av中文字幕在线观看| 一个人免费看片子| av免费观看日本| 久久精品夜色国产| 全区人妻精品视频| 久久精品久久精品一区二区三区| 亚洲三级黄色毛片| 亚洲美女视频黄频| 韩国高清视频一区二区三区| 91久久精品电影网| 亚洲综合精品二区| 亚洲在久久综合| 激情 狠狠 欧美| 国产精品国产av在线观看| 大码成人一级视频| 亚洲不卡免费看| 亚洲精品乱码久久久久久按摩| 亚洲va在线va天堂va国产| 人妻制服诱惑在线中文字幕| 九色成人免费人妻av| 久久久久久久久久久丰满| 亚洲欧美日韩无卡精品| 国产成人aa在线观看| 欧美精品一区二区大全| 亚洲精品国产av成人精品| 伦精品一区二区三区| 国产欧美另类精品又又久久亚洲欧美| 久久精品久久久久久久性| 国产爱豆传媒在线观看| 我要看黄色一级片免费的| 亚洲av二区三区四区| av在线播放精品| 亚洲精品一二三| 国产成人精品婷婷| 少妇精品久久久久久久| 在线观看一区二区三区| 免费看av在线观看网站| 亚洲天堂av无毛| 国产91av在线免费观看| 观看av在线不卡| 欧美极品一区二区三区四区| 男女边摸边吃奶| 黄色视频在线播放观看不卡| 亚洲国产高清在线一区二区三| 欧美成人a在线观看| 亚洲最大成人中文| 深爱激情五月婷婷| 亚洲精品一二三| 丰满迷人的少妇在线观看| 亚洲,欧美,日韩| 日本av手机在线免费观看| 人妻一区二区av| 日韩成人av中文字幕在线观看| 久久精品国产亚洲av涩爱| 偷拍熟女少妇极品色| 熟女av电影| 国产视频首页在线观看| 国产成人精品一,二区| 爱豆传媒免费全集在线观看| 国产亚洲av片在线观看秒播厂| 亚洲av福利一区| 国产成人a区在线观看| 亚洲一级一片aⅴ在线观看| 丝袜喷水一区| 国产精品国产三级专区第一集| 水蜜桃什么品种好| 寂寞人妻少妇视频99o| 能在线免费看毛片的网站| 熟女电影av网| 一区二区三区四区激情视频| 不卡视频在线观看欧美| 久久6这里有精品| 亚洲最大成人中文| 校园人妻丝袜中文字幕| 亚洲性久久影院| 天美传媒精品一区二区| 91精品一卡2卡3卡4卡| 观看美女的网站| 另类亚洲欧美激情| 搡老乐熟女国产| 色5月婷婷丁香| 免费观看无遮挡的男女| 免费观看av网站的网址| 亚洲国产色片| 国产乱人视频| 狂野欧美白嫩少妇大欣赏| 日韩人妻高清精品专区| 丝袜脚勾引网站| 国产永久视频网站| 最近2019中文字幕mv第一页| 中文字幕av成人在线电影| 亚洲人与动物交配视频| 亚洲精品视频女| 99热6这里只有精品| 亚洲精品自拍成人| 狂野欧美白嫩少妇大欣赏| 亚洲激情五月婷婷啪啪| 最近2019中文字幕mv第一页| 男女啪啪激烈高潮av片| 国产精品伦人一区二区| 成人国产av品久久久| 免费久久久久久久精品成人欧美视频 | 搡女人真爽免费视频火全软件| 99热这里只有精品一区| 九九久久精品国产亚洲av麻豆| 伊人久久国产一区二区| 一本色道久久久久久精品综合| 久久久久久久亚洲中文字幕| 亚洲国产欧美在线一区| 国产淫语在线视频| 一级a做视频免费观看| 午夜免费观看性视频| 91久久精品国产一区二区三区| 97超碰精品成人国产| 欧美日本视频| 国产亚洲午夜精品一区二区久久| 亚洲av中文字字幕乱码综合|