anonymous 16352 Nutrient and organic matter dynamics in Mombasa coastal waters (August 2021 - July 2022) Oduor, Nancy Awuor; Moosdorf, Nils (2026): Nutrient and organic matter dynamics in Mombasa coastal waters (August 2021 - July 2022) [dataset]. PANGAEA, https://doi.org/10.1594/PANGAEA.983442 Coastal waters in rapidly urbanizing regions face increasing threats from excessive nutrient and organic matter inputs, leading to eutrophication, habitat degradation, and harmful algal blooms. To address this issue, we conducted a comprehensive, year-long (August 2021–July 2022) nutrient monitoring study in Mombasa, Kenya representative city for developing coastal areas experiencing high population growth. Monthly surveys were carried out at geo-referenced sites, where environmental parameters such as temperature, salinity, dissolved oxygen (DO), and turbidity were measured in situ using a YSI Professional Plus Water Quality Meter (SKU6050000) and a Thermo Scientific™ Portable TN100 Turbidity Meter, respectively. Surface seawater samples were collected for dissolved inorganic nutrients, filtered immediately through 0.45 µm Sartorius Minisart® syringe filters, preserved with mercury chloride (50 µl of 20 g/L HgCl₂ per 100 ml), and stored cool until analysis. Pore water samples were also obtained during both dry and wet seasons. In the laboratory, concentrations of dissolved inorganic nutrients (nitrogen, phosphorus, silicates) were determined using spectrophotometry (Infinite® M200 NanoQuant, Tecan Group Ltd.) following standardized protocols Grasshoff et al., (2007). Submarine groundwater discharge (SGD) fluxes were estimated via radon isotope tracing using a Durridge RAD7 radon monitor alongside measurements of water parameters and meteorological data. All field sampling and measurements were performed in duplicate to ensure data quality, and geo-referencing was managed with KoboCollect v2022.2.3. This dataset provides critical insights into nutrient loading and its variability in tropical coastal environments, supporting future coastal management and research. 16360 https://doi.org/10.1594/PANGAEA.983442 2026-04-09T07:27:27+0000 2026 22588 22589 22590 15140 22591 15143 22592 14142 22593 22595 22596 22597 22598 22599 22600 22601 22602 22603 22604 22605 22606 22607 22608 22609 22610 22611 22612 22613 22614 22615 22616 22617 22618 22619 22620 22621 22622 22623 22624 22625 22626 22627 22628 22629 22630 22631 22632 22633 22634 22635 22636 22637 22638 22639 22640 22641 22642 22643 22644 22645 22646 22647 22648 22649 22650 22651 22652 22653 22654 22655 22656 22657 22658 22659 22660 22661 22662 22663 22664 22665 22666 22667 22668 22669 22670 22671 22672 22673 22674 22675 22676 22677 22678 22679 22680 22681 22682 22683 22685 22686 22687 22688 22689 22690 22691 22692 22693 22694 22695 22696 22697 22698 22699 22700 22701 22702 22703 22704 22705 22706 22707 22708 22709 22710 22711 22712 22713 22714 22715 22716 22717 22718 22719 22720 22721 22722 22723 22724 22725 22726 22727 22728 22729 22730 22731 22732 22733 22734 22735 22736 22737 22738 22739 22740 22741 22742 22743 22744 22745 22746 22747 22748 22749 22750 22751 22752 22753 22754 22755 22756 22757 22758 22759 22760 22761 22762 22763 22764 22765 22766 22767 22768 22769 22770 22771 22772 22773 22774 22775 22776 22777 22778 22779 22780 22781 22782 22783 22784 22785 22786 22787 22788 22789 22790 22791 22792 22793 22794 22795 22796 22797 22798 22799 22800 22801 22802 22803 22804 22805 22806 22807 22808 22809 22810 22811 22812 22813 22814 22815 22816 22817 22818 22819 22820 22821 22822 22823 22824 22825 22826 22827 22828 22829 22830 22831 22832 22833 22834 22835 22836 22837 22838 22839 22840 22841 22842 22843 22844 22845 22846 22847 22848 22849 22850 22851 22852 22853 22854 22855 22856 22857 22858 22859 22860 22861 22862 22863 22864 22865 22866 22867 22868 22869 22870 22871 22872 22873 22874 22875 22876 22877 22878 22879 22880 22881 22882 22883 22884 22885 22886 22887 22888 22889 22890 22891 22892 22893 22894 22895 22896 22897 22898 22899 22900 22901 22902 22903 22904 22905 22906 22907 22908 22909 22910 22911 22912 22913 22914 22915 22916 22917 22918 22919 22920 22921 22922 22923 22924 22925 22926 22927 22928 22929 22930 22931 22932 22933 22934 22935 22936 22937 22938 22939 22940 22941 22942 22943 22944 22945 22946 22947 22948 22949 22950 22951 22952 22953 22954 22955 22956 22957 22958 22959 22960 22961 22962 22963 22964 22965 22966 22967 22968 22969 22970 22971 22972 22973 22974 22975 22976 22977 22978 22980 22981 22982 22983 22984 22985 22986 22987 22988 22989 22990 22991 22992 22993 22994 22995 22996 22997 22998 22999 23000 23001 23002 23003 23004 23005 23006 23007 23008 23009 23010 23011 23012 23013 23014 23015 23016 23017 23018 23019 23020 23021 23022 23023 21413 23024