

FOLLOWUS
1.National Marine Environmental Monitoring Center, Dalian 116023, China
2.Ocean College of Hebei Agricultural University, Qinhuangdao 066003, China
duanweiyan@hebau.edu.cn
Received:10 November 2025,
Online First:15 September 2026,
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QU Limei,LI Hansen,DUAN Saipei,et al.Spatiotemporal dynamics of nutrients and eutrophication in Laizhou Bay: implications of long-term phosphorus limitation[J].Journal of Oceanology and Limnology,
QU Limei,LI Hansen,DUAN Saipei,et al.Spatiotemporal dynamics of nutrients and eutrophication in Laizhou Bay: implications of long-term phosphorus limitation[J].Journal of Oceanology and Limnology, DOI:.
Based on continuous monitoring data from 16 standardized monitoring stations in the coastal waters of Laizhou Bay
Shandong Province
from 2020 to 2024
we investigated the spatiotemporal distribution characteristics of nitrogen and phosphorus nutrients and assessed the eutrophication status. Results indicate that the concentration of dissolved inor
ganic nitrogen (DIN) in the bay exhibited significant seasonal and spatial variations
and the overall trend was higher in the west and lower in the east
while the concentration of dissolved inorganic phosphorus (DIP) remained relatively stable. Specifically
the DIN concentration in spring was significantly higher than that in summer and autumn. The N/P ratio showed an initial increase followed by a decreasing trend during 2020–2024; however
the overall ratio remained substantially higher than the Redfield ratio
indicating a pronounced phosphorus-limited condition in the bay. Eutrophication assessment revealed that the eutrophication index (EI) in autumn was significantly higher than that in spring and summer. The western coastal area of the bay top was identified as a high-risk zone for eutrophication
while the outer bay maintained an oligotrophic state throughout the year. Complex coupling relationships were observed among pH
dissolved oxygen (DO)
chemical oxygen demand (COD
Mn
)
and nutrients. Specifically
pH and DO exhibited weak correlations with nutrient levels
whereas COD
Mn
showed a significant positive correlation with nutrients. The findings provide a theoretical reference for the construction of the Beautiful Bays Initiative in Shandong Province.
Baek J Y , Guerreiro C V , Kim J et al . 2024 . Coastal environmental changes after the Saemangeum seawall construction. Frontiers in Marine Science , 10 : 1307218 , https://doi.org/10.3389/fmars.2023.1307218 https://doi.org/10.3389/fmars.2023.1307218 .
Cai W J , Hu X P , Huang W J et al . 2011 . Acidification of subsurface coastal waters enhanced by eutrophication . Nature Geoscience , 4 ( 11 ): 766 - 770 , https://doi.org/10.1038/ngeo1297 https://doi.org/10.1038/ngeo1297 .
Chen J L , Shao X S , Li F et al . 2025 . Habitat distribution and driving mechanisms of Portunus trituberculatus across different life history stages in the southern Bohai Sea. Marine Environmental Research , 210 : 107347 , https://doi.org/10.1016/j.marenvres.2025.107347 https://doi.org/10.1016/j.marenvres.2025.107347 .
Department of Ecology and Environment of Shandong Province . 2023 . http://xxgk.sdein.gov.cn/xxgkml/hjzkgb/202406/t20240606_4734870.html http://xxgk.sdein.gov.cn/xxgkml/hjzkgb/202406/t20240606_4734870.html . (in Chinese)
Dong X X , Li J H , Sun S et al . 2023 . The spatial distribution characteristics of nutrients in the coastal waters of Laizhou Bay in spring and autumn 2020 . Ocean Development and Management , 40 ( 6 ): 85 - 92 , https://doi.org/10.20016/j.cnki.hykfygl.20230713.007. https://doi.org/10.20016/j.cnki.hykfygl.20230713.007. (in Chinese with English abstract)
Duan H L , Yu X B . 2023 . Variation of waterbird habitat in the Yellow and Bohai Seas, China . Acta Ecologica Sinica , 43 ( 15 ): 6354 - 6363 , https://doi.org/10.5846/stxb202207202071 https://doi.org/10.5846/stxb202207202071 .
Duan S W , Zhang S , Huang H Y . 2000 . Transport of dissolved inorganic nitrogen from the major rivers to estuaries in China . Nutrient Cycling in Agroecosystems , 57 ( 1 ): 13 - 22 , https://doi.org/10.1023/A:1009896032188 https://doi.org/10.1023/A:1009896032188 .
General Administration of Quality Supervision , Inspection and Quarantine of the People's Republic of China , Standardization Administration of the People's Republic of China . 2008a . The Specification for Marine Monitoring—Part 3: Sample Collection Storage and Transportation: GB 17378 . 3 -2007. Standards Press of China, Beijing. (in Chinese)
General Administration of Quality Supervision , Inspection and Quarantine of the People's Republic of China , Standardization Administration of the People's Republic of China . 2008b . The Specification for Marine Monitoring—Part 4: Seawater Analysis: GB 17378 . 4 -2007. Standards Press of China, Beijing. (in Chinese)
Gobler C J , Baumann H . 2016 . Hypoxia and acidification in ocean ecosystems: coupled dynamics and effects on marine life . The Biology Letters , 12 ( 5 ): 20150976 , https://doi.org/10.1098/rsbl.2015.0976 https://doi.org/10.1098/rsbl.2015.0976 .
Guo F , Liu S , Wang F F et al . 2016 . Distribution of nutrients in the summer of Laizhou Bay and influence factors . Marine Geology Frontiers , 32 ( 2 ): 38 - 44 , https://doi.org/10.16028/j.1009-2722.2016.02006. https://doi.org/10.16028/j.1009-2722.2016.02006. (in Chinese with English abstract)
Hagstrom G I , Stock C A , Luo J Y et al . 2024 . Impact of dynamic phytoplankton stoichiometry on global scale patterns of nutrient limitation, nitrogen fixation, and carbon export . Global Biogeochemical Cycles , 38 ( 5 ): e2023 GB 007991 , https://doi.org/10.1029/2023GB007991 https://doi.org/10.1029/2023GB007991 .
Han Y , Zheng Z L , Chen X W et al . 2024 . Study on temporal and spatial distribution and eutrophication of nutrients in Sanya River . Environmental Chemistry , 43 ( 2 ): 524 - 535 , https://doi.org/10.7524/j.issn.0254-6108.2022080104. https://doi.org/10.7524/j.issn.0254-6108.2022080104. (in Chinese with English abstract)
Howarth R W , Marino R . 2006 . Nitrogen as the limiting nutrient for eutrophication in coastal marine ecosystems: evolving views over three decades. Limnology and Oceanography , 51 (1part 2 ): 364 - 376 , https://doi.org/10.4319/lo.2006.51.1_part_2.0364 https://doi.org/10.4319/lo.2006.51.1_part_2.0364 .
Huang Q , Olenin S , Sun S et al . 2018 . Impact of farming non-indigenous scallop Argopecten irradians on benthic ecosystem functioning: a case-study in Laizhou Bay, China . Aquaculture Environment Interactions , 10 : 227 - 241 , https://doi.org/10.3354/aei00264 https://doi.org/10.3354/aei00264 .
Igwaran A , Kayode A J , Moloantoa K M et al . 2024 . Cyanobacteria harmful algae blooms: causes, impacts, and risk management . Water, Air, & Soil Pollution , 235 ( 1 ): 71 , https://doi.org/10.1007/s11270-023-06782-y https://doi.org/10.1007/s11270-023-06782-y .
IPCC . 2021 . Climate change 2021: the physical science basis . In: Eyring V, Gillett N P, Gulev S K et al eds. Cross-Chapter Box 2.2: Large-scale Indicators of Climate Change. Cambridge University Press , Cambridge . p. 312 -313, https://doi.org/10.1017/9781009157896.004 https://doi.org/10.1017/9781009157896.004 .
Jiang H C , Wang Y J , Li J H et al . 2018 . Annual variation and spatial distribution of nutrients in the Laizhou Bay . Marine Science Bulletin , 37 ( 4 ): 411 - 423 , https://doi.org/10.11840/j.issn.1001-6392.2018.04.007. https://doi.org/10.11840/j.issn.1001-6392.2018.04.007. (in Chinese with English abstract)
Jinan Urban and Rural Taxation Bureau . 2022 . Jinan Water Resources Bulletin . http://wr.shandong.gov.cn/xwzx_319/bmdt/202210/t20221013_4098565.html http://wr.shandong.gov.cn/xwzx_319/bmdt/202210/t20221013_4098565.html . (in Chinese)
Ju P L , Cheung W W L , Chen M R et al . 2020 . Comparing marine ecosystems of Laizhou and Haizhou Bays, China, using ecological indicators estimated from food web models. Journal of Marine Systems , 202 : 103238 , https://doi.org/10.1016/j.jmarsys.2019.103238 https://doi.org/10.1016/j.jmarsys.2019.103238 .
Kong M , Li W H , Wang C et al . 2025 . Analysis of water environment quality and phytoplankton community structure in the nearshore waters of the Yellow River estuary from 2020 to 2024 . Environmental Monitoring and Forewarning , 17 ( 4 ): 1 - 7 , 25 , https://doi.org/10.3969/j.issn.1674-6732.2025.04.001. https://doi.org/10.3969/j.issn.1674-6732.2025.04.001. (in Chinese with English abstract) .
Laurent A , Fennel K , Cai W J et al . 2017 . Eutrophication‐induced acidification of coastal waters in the northern Gulf of Mexico: insights into origin and processes from a coupled physical‐biogeochemical model . Geophysical Research Letters , 44 ( 2 ): 946 - 956 , https://doi.org/10.1002/2016GL071881 https://doi.org/10.1002/2016GL071881 .
Lee J , Park K T , Lim J H et al . 2018 . Hypoxia in Korean coastal waters: a case study of the natural Jinhae Bay and artificial Shihwa Bay. Frontiers in Marine Science , 5 : 70 , https://doi.org/10.3389/fmars.2018.00070 https://doi.org/10.3389/fmars.2018.00070 .
Li H G , Li S S , Zhang M Z et al . 2024 . Typhoon-induced stormwater drives nutrient dynamics and triggers phytoplankton blooms in Laizhou Bay, China. Marine Environmental Research , 198 : 106473 , https://doi.org/10.1016/j.marenvres.2024.106473 https://doi.org/10.1016/j.marenvres.2024.106473 .
Li Y , Song G S , Massicotte P et al . 2019 . Distribution, seasonality, and fluxes of dissolved organic matter in the Pearl River (Zhujiang) estuary, China . Biogeosciences , 16 ( 13 ): 2751 - 2770 , https://doi.org/10.5194/bg-16-2751-2019 https://doi.org/10.5194/bg-16-2751-2019 .
Li Y F , Song X X , Wu Z X et al . 2015 . An integrated methodology for quantitative assessment on impact of human activities on marine ecosystems: a case study in Laizhou Bay, China . Oceanology et Limnologia Sinica , 46 ( 1 ): 133 - 139 , https://doi.org/10.11693/hyhz20140200060. https://doi.org/10.11693/hyhz20140200060. (in Chinese with English abstract)
Liang H R , Zhang J X , Zhang J B et al . 2024 . Unveiling the eutrophication crisis: 20 years of nutrient development in Zhanjiang Bay, China. Frontiers in Marine Science , 11 : 1373716 , https://doi.org/10.3389/fmars.2024.1373716 https://doi.org/10.3389/fmars.2024.1373716 .
Liang S K , Li S S , Ma H Y et al . 2022 . Spatial-temporal distributions and limiting factors of nutrients in Laizhou Bay based on land-sea synchronous survey . Periodical of Ocean University of China , 52 ( 8 ): 97 - 110 , https://doi.org/10.16441/j.cnki.hdxb.20220068. https://doi.org/10.16441/j.cnki.hdxb.20220068. (in Chinese with English abstract)
Liu C , Wang Z Y , He Y . 2003 . Water pollution in the river mouths around Bohai Bay . International Journal of Sediment Research , 18 ( 4 ): 326 - 332 .
Liu X H , Liu D Y , Wang Y J et al . 2019 . Temporal and spatial variations and impact factors of nutrients in Bohai Bay, China . Marine Pollution Bulletin , 140 : 549 - 562 , https://doi.org/10.1016/j.marpolbul.2019.02.011 https://doi.org/10.1016/j.marpolbul.2019.02.011 .
Liu Z N , Sun W F , Chen L . 2024 . Retrieval of sea surface salinity in the Bohai Sea by neural network . Digital Ocean & Underwater Warfare , 7 ( 1 ): 79 - 86 , https://doi.org/10.19838/j.issn.2096-5753.2024.07.010. https://doi.org/10.19838/j.issn.2096-5753.2024.07.010. (in Chinese with English abstract)
Lu Q Y , Zhang M , Zhao K X et al . 2025 . Temporal and spatial changes and eutrophication evaluation of dissolved inorganic nitrogen and phosphate in Laizhou Bay . Transactions of Oceanology and Limnology , 47 ( 2 ): 109 - 117 , https://doi.org/10.13984/j.cnki.cn37-1141.2025.02.014. https://doi.org/10.13984/j.cnki.cn37-1141.2025.02.014. (in Chinese with English abstract)
Luo Y , Liu J W , Wu J W et al . 2022 . Comprehensive assessment of eutrophication in Xiamen Bay and its implications for management strategy in Southeast China . International Journal of Environmental Research and Public Health , 19 ( 20 ): 13055 , https://doi.org/10.3390/ijerph192013055 https://doi.org/10.3390/ijerph192013055 .
Ministry of Ecology and Environment of the People's Republic China , 2020 . Technical Specification for Offshore Environmental Monitoring Part 10 Evaluation and Report: HJ 442 . 10 - 2020 . China Environmental Science Press, Beijing. (in Chinese)
Qiao L L , Wang W M , Liu Y R et al . 2025 . Changes and influencing factors of phytoplankton in the Tianjin coastal waters of Bohai Bay at the early stage of COVID-19 outbreak. Marine Pollution Bulletin , 211 : 117496 , https://doi.org/10.1016/j.marpolbul.2024.117496 https://doi.org/10.1016/j.marpolbul.2024.117496 .
Qu L M , Feng P F , Cong P F et al . 2025 . Spatial-temporal d istribution of nitrogen and phosphorus nutrients and potential eutrophication assessment in Bohai Bay, China. Ocean & Coastal Management , 267 : 107741 , https://doi.org/10.1016/j.ocecoaman.2025.107741 https://doi.org/10.1016/j.ocecoaman.2025.107741 .
Ren Z , Yu J L , Lin Z M et al . 2024 . Estimating nutrient stoichiometry and cascading influences on plankton in thermokarst lakes on the Qinghai-Tibet Plateau . Communications Earth & Environment , 5 ( 1 ): 682 , https://doi.org/10.1038/s43247-024-01859-w https://doi.org/10.1038/s43247-024-01859-w .
Shandong Provincial Bureau of Oceanography . 2024 . Shandong marine economy statistical bulletin 2023. Document No. Lu-Hai-Fa [2024] No . 5 . http://hyj.shandong.gov.cn/zwgk/fdzdgk/hyzlghyjj/202404/P020240425601507779954.pdf http://hyj.shandong.gov.cn/zwgk/fdzdgk/hyzlghyjj/202404/P020240425601507779954.pdf . (in Chinese)
Shandong Provincial People's Government . 2008 . Opinions on supporting the sound and rapid development of the Yellow River Delta high-efficiency ecological economic zone . http://www.shandong.gov.cn/art/2008/11/25/art_100623_23483.html http://www.shandong.gov.cn/art/2008/11/25/art_100623_23483.html . (in Chinese)
Shandong Provincial People's Government . 2025 . Shandong Provincial port and waterway layout plan ( 2025-2035 ). https://jtt.shandong.gov.cn/art/2025/7/24/art_100537_10325108.html https://jtt.shandong.gov.cn/art/2025/7/24/art_100537_10325108.html . (in Chinese)
State Environmental Protection Administration , 1997 .. SeaWater Quality Standard: GB 3097-1997 . China Environmental Science Press , Beijing . (in Chinese) .
Sun J W , Peng L H , Zhu X W et al . 2024a . The effects of changes in the coastline and water depth on tidal prism and water exchange of the Laizhou Bay, China. Frontiers in Marine Science , 11 : 1459482 , https://doi.org/10.3389/fmars.2024.1459482 https://doi.org/10.3389/fmars.2024.1459482 .
Sun R H , Kang X Y , Xia M . 2024b . The roles of nutrient loading and river discharge on the phytoplankton dynamics in the semi-enclosed sea . Journal of Geophysical Research: Oceans , 129 ( 12 ): e2024 JC 021466 , https://doi.org/10.1029/2024JC021466 https://doi.org/10.1029/2024JC021466 .
Wang B D , Xin M , Wei Q S et al . 2018 . A historical overview of coastal eutrophication in the China seas . Marine Pollution Bulletin , 136 : 394 - 400 , https://doi.org/10.1016/j.marpolbul.2018.09.044 https://doi.org/10.1016/j.marpolbul.2018.09.044 .
Wang L , Wang X , Meng Q H et al . 2023a . Extraction and application of Forel-Ule Index from sentinel-3 OLCI image in the Bohai Sea . Environmental Monitoring in China , 39 ( 4 ): 248 - 256 , https://link.oversea.cnki.net/doi/10.19316/j.issn.1002-6002.2023.04.25. https://link.oversea.cnki.net/doi/10.19316/j.issn.1002-6002.2023.04.25. (in Chinese with English abstract)
Wang M R , Kroeze C , Strokal M et al . 2020 . Global change can make coastal eutrophication control in China more difficult . Earth's Future , 8 ( 4 ): e2019 EF 001280 , https://doi.org/10.1029/2019EF001280 https://doi.org/10.1029/2019EF001280 .
Wang Y , Zhang H M , Wu N et al . 2022 . Monthly variation of nutrient concentration in the lower reaches of the Yellow River and its response to the flood discharge event of the reservoir . Periodical of Ocean University of China , 52 ( 3 ): 88 - 98 , https://doi.org/10.16441/j.cnki.hdxb.20210108. https://doi.org/10.16441/j.cnki.hdxb.20210108. (in Chinese with English abstract)
Wang Y N , Guan W C , Zou L et al . 2023b . Composition and transport of nitrogen and phosphorus in the main estuaries around Laizhou Bay . Marine Environmental Science , 42 ( 5 ): 684 - 692 , https://doi.org/10.13634/j.cnki.mes.2023.05.011. https://doi.org/10.13634/j.cnki.mes.2023.05.011. (in Chinese with English abstract)
Wang Z J , Bao R , Wang W Z et al . 2024 . Impacts of a marine engineering project on hydrodynamics and diffusion characteristics of fluvial pollutants in Laizhou Bay, China. Frontiers in Earth Science , 12 : 1432090 , https://doi.org/10.3389/feart.2024.1432090 https://doi.org/10.3389/feart.2024.1432090 .
Wetzel R G . 2001 . Limnology: Lake and River Ecosystems . Academic Press , San Diego . https://do 10.1016/b978-0-08-057439-4.50012-5 http://dx.doi.org/10.1016/b978-0-08-057439-4.50012-5
Wu K Y , Xiu B , Cui D D et al . 2024 . Composition and distribution of nutrients and environmental capacity in Dapeng Bay, northern South China Sea. Marine Pollution Bulletin , 206 : 116689 , https://doi.org/10.1016/j.marpolbul.2024.116689 https://doi.org/10.1016/j.marpolbul.2024.116689 .
Yang F , Li J , Wang J Q et al . 2021 . Spatiotemporal characteristics of human activity on coastal landscape of Laizhou Bay . Wetlands Ecology and Management , 29 ( 6 ): 789 - 808 , https://doi.org/10.1007/s11273-021-09810-y https://doi.org/10.1007/s11273-021-09810-y .
Yang S , Song N , Gao T X et al . 2017 . Tracking surveys and growth study of released Fenneropenaeus Chinensis . Transactions of Oceanology and Limnology , 1 ): 102 - 108 , https://doi.org/10.13984/j.cnki.cn37-1141.2017.01.014. https://doi.org/10.13984/j.cnki.cn37-1141.2017.01.014. (in Chinese with English abstract
You L P , Zhao Y T , Sun S et al . 2018 . Characteristics of nutrient structures and limitations in Laizhou Bay in the spring and summer of 2018 . Progress in Fishery Sciences , 42 ( 6 ): 15 - 24 , https://doi.org/10.19663/j.issn2095-9869.20200715001. https://doi.org/10.19663/j.issn2095-9869.20200715001. (in Chinese with English abstract)
Yu L L , Chen Y L , Zhang H N et al . 2016 . Environmental capacity calculation of nutrients in the Laizhou Bay based on the nonlinear programming . Advances in Marine Science , 34 ( 2 ): 304 - 312 , https://doi.org/10.3969/j.issn.1671-6647.2016.02.015. https://doi.org/10.3969/j.issn.1671-6647.2016.02.015. (in Chinese with English abstract)
Zhai W D , Zheng L W , Li C L et al . 2020 . Changing nutrients, dissolved oxygen and carbonate system in the Bohai and Yellow Seas, China . In: Chen C T A, Guo X Y eds. Changing Asia-Pacific Marginal Seas . Springer, Singapore . p. 121 - 137 . https://do 10.1007/978-981-15-4886-4_8 http://dx.doi.org/10.1007/978-981-15-4886-4_8
Zhang F F , Fu H R , Lou H W et al . 2023 . Assessment of eutrophication from Xiaoqing River estuary to Laizhou Bay: further warning of ecosystem degradation in typically polluted estuary. Marine Pollution Bulletin , 193 : 115209 , https://doi.org/10.1016/j.marpolbul.2023.115209 https://doi.org/10.1016/j.marpolbul.2023.115209 .
Zhang G C , Jun S . 2023 . State of environmental pollution in the Bohai Sea, China: a review . Environmental Chemistry , 42 ( 3 ): 918 - 930 , https://doi.org/10.7524/j.issn.0254-6108.2022101805. https://doi.org/10.7524/j.issn.0254-6108.2022101805. (in Chinese with English abstract)
Zhang H B , Pei S F , Zhu Y X et al . 2018 . Nutrient structure and nutrient limitation for phytoplankton growth in Bohai Bay in the early summer . China Environmental Science , 38 ( 9 ): 3524 - 3530 , https://doi.org/10.3969/j.issn.1000-6923.2018.09.039. https://doi.org/10.3969/j.issn.1000-6923.2018.09.039. (in Chinese with English abstract)
Zhang L , Song C L , Zhang N X et al . 2017 . Nutrient distribution and eutrophication assessment in west sea area of Laizhou Bay . Journal of Guangxi Academy of Sciences , 33 ( 2 ): 82 - 86 , https://doi.org/10.13657/j.cnki.gxkxyxb.20161209.002. https://doi.org/10.13657/j.cnki.gxkxyxb.20161209.002. (in Chinese with English abstract)
Zhang M , Lu Q Y , Wang D W et al . 2022a . Spatiotemporal evolution of nutrients and the influencing factors in Laizhou Bay over the past 40 years. Marine Pollution Bulletin , 184 : 114186 , https://doi.org/10.1016/j.marpolbul.2022.114186 https://doi.org/10.1016/j.marpolbul.2022.114186 .
Zhang X , Zhang L J , Hou Z L et al . 2012 . Spatio-temporal variability of principal pollutants in Laizhou Bay from 1980 to 2008 . Periodical of Ocean University of China , 42 ( 11 ): 91 - 98 , https://doi.org/10.16441/j.cnki.hdxb.2012.11.015. https://doi.org/10.16441/j.cnki.hdxb.2012.11.015. (in Chinese with English abstract)
Zhang X S , Chen S Q , Han X R et al . 2022b . Effects of organic nitrogen components from terrestrial input on the phytoplankton community in Jiaozhou Bay. Marine Pollution Bulletin , 174 : 113316 , https://doi.org/10.1016/j.marpolbul.2021.113316 https://doi.org/10.1016/j.marpolbul.2021.113316 .
Zheng L W , Zhai W D . 2023 . Nutrient dynamics in the Bohai and North Yellow seas from seasonal to decadal scales: unveiling Bohai Sea eutrophication mitigation in the 2010s. Science of the Total Environment , 905 : 167417 , https://doi.org/10.1016/j.scitotenv.2023.167417 https://doi.org/10.1016/j.scitotenv.2023.167417 .
Zheng X L , Zhang J J , Chen L . 2013 . Advances in the study of migration and transformation mechanisms of endogenous phosphorus via sediment resuspension . Advances in Water Science , 24 ( 2 ): 287 - 295 , https://doi.org/10.14042/j.cnki.32.1309.2013.02.010. https://doi.org/10.14042/j.cnki.32.1309.2013.02.010. (in Chinese with English abstract)
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