Skip to main content


Log in

Impact of agricultural practices on ecosystem health of lagoons: a case study of the Keta Lagoon Complex in Ghana, West Africa

  • Research
  • Published:
Environmental Monitoring and Assessment Aims and scope Submit manuscript


The paper reports on the current ecological health of the Keta Lagoon Complex by analyzing a suite of physical, chemical, and biological environmental conditions prevailing within it. Results are discussed in relation to the main human activity (i.e., agriculture) prevailing in its catchment. The current water quality of the lagoon has declined compared to data collected 20 years ago with elevated levels in parameters such as nitrate, phosphate, turbidity, and temperature. Secchi disk depth, salinity, and dissolved oxygen levels in the lagoon have decreased. More than 60% of the total area of the lagoon is predicted to be currently unsuitable to support aquatic life. The Carlson’s TSI estimated for the various zones of the lagoon ranged between 72.40 and 80.61 depicting a highly eutrophic lagoon, with about 90% of the total area studied confirmed to be experiencing some degree of eutrophication. The plankton index of biotic integrity also yielded high values of between 3 and 6 in most areas of the lagoon, thereby affirming the poor health of the lagoon. The diversity of phytoplankton and benthic macroinvertebrate species in the lagoon has reduced significantly in the last two decades with about 11 genera of phytoplankton missing in the present study. Benthic macroinvertebrate assemblage richness, evenness, and diversity have decreased from 3.6, 2.0, and 5.8 in 2008 to 1.2, 0.8, and 1.7 respectively, in the present study. Overall, the health of the Keta Lagoon remains poorer and continues to decline with no signs of recovery.

Graphical Abstract

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4

Similar content being viewed by others

Data availability

The authors agree to make the data from the study available to interested readers anytime upon request through the corresponding author.


  • Ababio, S. (2001). The population parameters, food habitats and physico-chemical environment of three Cichlid species in the southwestern sector of the Keta lagoon MPhil Thesis. University of Ghana, Legon].

  • Addo, C., Ofori-Danson, K., Mensah, A., & Takyi, R. (2014). The fisheries and primary productivity of the Keta Lagoon. World Journal of Biological Research, 6(1).

  • Agyare, A. K., Murray, G., Dearden, P., & Rollins, R. (2015). Understanding inter-community performance assessments in community-based resource management at Avu Lagoon, Ghana. Environment, Development and Sustainability, 17, 1493–1508.

    Article  Google Scholar 

  • Aminot, A., & Rey, F. (2000). Standard procedure for the determination of chlorophyll a by spectroscopic methods. International Council for the Exploration of the Sea, 112, 25.

    Google Scholar 

  • Appeaning Addo, K., Brempong, E., & Jayson-Quashigah, P. (2020). Assessment of the dynamics of the Volta river estuary shorelines in Ghana. Geoenvironmental Disasters, 7, 1–11.

    Article  Google Scholar 

  • Asomaning, S., Abekoe, M., Dowuona, G., Borggaard, O., Kristensen, J., & Breuning-Madsen, H. (2015). Sustainable long-term intensive application of manure to sandy soils without phosphorus leaching: A case study from Ghana. Acta Agriculturae Scandinavica, Section B—Soil & Plant Science, 65(8), 747–754.

  • Awadzi, T., Ahiabor, E., & Breuning-Madsen, H. (2008). The soil-land use system in a sand spit area in the semi-arid coastal savanna region of Ghana–development, sustainability and threats. West African Journal of Applied Ecology, 13(1), 132–143.

    Article  Google Scholar 

  • Baker, A. (2006). Land use and water quality. In M. G. Anderson, & J. J. McDonnell (Eds.), Encyclopedia of Hydrological Sciences (Vol. 49, pp. 2925–2930). Chichester, UK: John Wiley and Sons Ltd.

  • Barik, S. K., Muduli, P. R., Mohanty, B., Behera, A. T., Mallick, S., Das, A., Samal, R., Rastogi, G., & Pattnaik, A. K. (2017). Spatio-temporal variability and the impact of Phailin on water quality of Chilika lagoon. Continental Shelf Research, 136, 39–56.

    Article  Google Scholar 

  • Benáková, A., Johanidesová, I., Kelbich, P., Pospíšil, V., & Wanner, J. (2018). The increase of process stability in removing ammonia nitrogen from wastewater. Water Science and Technology, 77(9), 2213–2219.

    Article  Google Scholar 

  • Boesch, D. F., Boynton, W. R., Crowder, L. B., Diaz, R. J., Howarth, R. W., Mee, L. D., Nixon, S. W., Rabalais, N. N., Rosenberg, R., & Sanders, J. G. (2009). Nutrient enrichment drives Gulf of Mexico hypoxia. Eos, Transactions American Geophysical Union, 90(14), 117–118.

    Article  Google Scholar 

  • Buck, O., Niyogi, D. K., & Townsend, C. R. (2004). Scale-dependence of land use effects on water quality of streams in agricultural catchments. Environmental Pollution, 130(2), 287–299.

    Article  CAS  Google Scholar 

  • Burkholder, J. M., Tomasko, D. A., & Touchette, B. W. (2007). Seagrasses and eutrophication. Journal of Experimental Marine Biology and Ecology, 350(1–2), 46–72.

    Article  Google Scholar 

  • Camara, M., Jamil, N. R., & Abdullah, A. F. B. (2019). Impact of land uses on water quality in Malaysia: A review. Ecological Processes, 8(1), 1–10.

    Article  Google Scholar 

  • Carlson, R. (2007). Estimating Trophic State. Lakeline, 27(1), 25–28.

    Google Scholar 

  • Cash, K., & Wright, R. (2001). Canadian water quality guidelines for the protection of aquatic life. In: CCME.

  • Codjoe, S. N. A., Appeaning Addo, K., Addoquaye Tagoe, C., Nyarko, B. K., Martey, F., Nelson, W. A., Jayson-Quashigah, P.-N., Atiglo, D. Y., Adjei, P. O.-W., & Anderson, K. (2020). The Volta Delta, Ghana: Challenges in an African Setting. Deltas in the Anthropocene, 79–102.

  • Corrales, R. A., & Maclean, J. L. (1995). Impacts of harmful algae on seafarming in the Asia-Pacific areas. Journal of Applied Phycology, 7, 151–162.

    Article  Google Scholar 

  • de Mello, K., Valente, R. A., Randhir, T. O., dos Santos, A. C. A., & Vettorazzi, C. A. (2018). Effects of land use and land cover on water quality of low-order streams in Southeastern Brazil: Watershed versus riparian zone. CATENA, 167, 130–138.

    Article  Google Scholar 

  • Diaz, R. J. (2001). Overview of hypoxia around the world. Journal of Environmental Quality, 30(2), 275–281.

    Article  CAS  Google Scholar 

  • Diaz, R. J., & Rosenberg, R. (2008). Spreading dead zones and consequences for marine ecosystems. science, 321(5891), 926–929.

  • Dorgham, M. M. (2014). Effects of eutrophication. Eutrophication: Causes. Consequences and Control:, 2, 29–44.

    Google Scholar 

  • Duku, E., Mattah, P. A. D., & Angnuureng, D. B. (2021). Assessment of land use/land cover change and morphometric parameters in the Keta Lagoon Complex Ramsar Site. Ghana. Water, 13(18), 2537.

    Article  Google Scholar 

  • EPA, U. (2022). National Recommended Aquatic Life Criteria table. Retrieved March 1, 2023, from

  • Finlayson, C., Gordon, C., Ntiamoa-Baidu, Y., Tumbulto, J., & Storrs, M. (2000). Hydrobiology of the Songor and Keta lagoons: Implications for wetland management in Ghana. Supervising Scientist Report, 152, 167.

    Google Scholar 

  • Finlayson, C., Gordon, C., Storrs, M., & Ntiamoa-Baidu, Y. (2002). Ecological character of two lagoons in the lower Volta, Ghana1. Research Institute, 114.

  • Galvão, S. R. D. S., & Salcedo, I. H. (2009). Soil phosphorus fractions in sandy soils amended with cattle manure for long periods. Revista Brasileira De Ciência Do Solo, 33, 613–622.

    Article  Google Scholar 

  • Gardner, R. C., & Davidson, N. C. (2011). The ramsar convention. Wetlands: Integrating multidisciplinary concepts, 189–203.

  • Gildeeva, O., Akita, L. G., Biehler, J., Frenzel, P., & Alivernini, M. (2021). Recent brackish water Foraminifera and Ostracoda from two estuaries in Ghana, and their potential as (palaeo) environmental indicators. Estuarine, Coastal and Shelf Science, 256, 107270.

    Article  Google Scholar 

  • Harper, D. M. (1992). Eutrophication of freshwaters. Springer.

    Book  Google Scholar 

  • Howarth, R., Chan, F., Conley, D. J., Garnier, J., Doney, S. C., Marino, R., & Billen, G. (2011). Coupled biogeochemical cycles: Eutrophication and hypoxia in temperate estuaries and coastal marine ecosystems. Frontiers in Ecology and the Environment, 9(1), 18–26.

    Article  Google Scholar 

  • Huang, J., Zhan, J., Yan, H., Wu, F., & Deng, X. (2013). Evaluation of the impacts of land use on water quality: A case study in the Chaohu Lake Basin. The Scientific World Journal, 329187, 1–7.

  • Huff, L., Delos, C., Gallagher, K., & Beaman, J. (2013). Aquatic life ambient water quality criteria for ammonia-freshwater. US Environmental Protection Agency.

    Google Scholar 

  • Innes, R. (2013). Economics of agricultural residuals and overfertilization: Chemical fertilizer use, livestock waste, manure management, and environmental impacts. Encyclopedia of energy, natural resource, and environmental economics, 50–57.

  • Kändler, M., Blechinger, K., Seidler, C., Pavlů, V., Šanda, M., Dostál, T., Krása, J., Vitvar, T., & Štich, M. (2017). Impact of land use on water quality in the upper Nisa catchment in the Czech Republic and in Germany. Science of the Total Environment, 586, 1316–1325.

    Article  Google Scholar 

  • Kane, D. D. (2004). The development of a planktonic index of biotic integrity for Lake Erie. The Ohio State University.

  • Kane, D. D., Gordon, S. I., Munawar, M., Charlton, M. N., & Culver, D. A. (2009). The planktonic index of biotic integrity (P-IBI): An approach for assessing lake ecosystem health. Ecological Indicators, 9(6), 1234–1247.

    Article  CAS  Google Scholar 

  • Lamptey, A. M., Ofori-Danson, P. K., Abbenney-Mickson, S., Breuning-Madsen, H., & Abekoe, M. K. (2013). The influence of land-use on water quality in a tropical coastal area: case study of the Keta lagoon complex, Ghana, West Africa. Open Journal of Modern Hydrology, 2013.

  • Lamptey, E., & Armah, A. K. (2008). Factors affecting macrobenthic fauna in a tropical hypersaline coastal lagoon in Ghana, West Africa. Estuaries and Coasts, 31, 1006–1019.

    Article  Google Scholar 

  • Lamptey, M., & Ofori-Danson, P. (2014). The status of fish diversity and fisheries of the Keta Lagoon, Ghana, West Africa. Ghana Journal of Science, 54, 3–18.

    Google Scholar 

  • Li, S., Gu, S., Liu, W., Han, H., & Zhang, Q. (2008). Water quality in relation to land use and land cover in the upper Han River Basin. China. Catena, 75(2), 216–222.

    Article  CAS  Google Scholar 

  • Margalef, R. (1973). Information theory in ecology. General Systems, 3, 36–37.

  • Nortsu, O. (2018). Flooding related challenges of lagoon settlements: A case study of Keta, Ghana University of Cape Coast].

  • Pawlisz, A., Kent, R., Schneider, U., & Jefferson, C. (1997). Canadian water quality guidelines for chromium. Environmental Toxicology and Water Quality: An International Journal, 12(2), 123–183.

    Article  CAS  Google Scholar 

  • Peng, S., Buresh, R. J., Huang, J., Zhong, X., Zou, Y., Yang, J., Wang, G., Liu, Y., Hu, R., & Tang, Q. (2010). Improving nitrogen fertilization in rice by sitespecific N management. A Review. Agronomy for Sustainable Development, 30, 649–656.

    Article  CAS  Google Scholar 

  • Peters, M. K., & Kusimi, J. M. (2023). Changes in wetland and other landscape elements of the Keta Municipal area of Ghana. Journal of Coastal Conservation, 27(1), 1.

    Article  Google Scholar 

  • Pielou, E. C. (1966). The measurement of diversity in different types of biological collections. Journal of Theoretical Biology, 13, 131–144.

    Article  Google Scholar 

  • Porter, G., Young, E., & Dzietror, A. (1997). Pressures on an intensive irrigated cash-crop system in coastal Ghana. Geoforum, 28(3–4), 329–340.

    Article  Google Scholar 

  • Postel, S., & Carpenter, S. (1997). Freshwater ecosystem services. Nature’s services: Societal dependence on natural ecosystems, 195.

  • Rabalais, N. N., & Turner, R. E. (2019). Gulf of Mexico hypoxia: Past, present, and future. Limnology and Oceanography Bulletin, 28(4), 117–124.

    Article  Google Scholar 

  • Rabalais, N. N., Turner, R. E., & Wiseman, W. J., Jr. (2001). Hypoxia in the Gulf of Mexico. Journal of Environmental Quality, 30(2), 320–329.

    Article  CAS  Google Scholar 

  • Rahman, K. A., & Zhang, D. (2018). Effects of fertilizer broadcasting on the excessive use of inorganic fertilizers and environmental sustainability. Sustainability, 10(3), 759.

    Article  Google Scholar 

  • Rast, W., & Lee, G. F. (1978). Summary analysis of the North American (US Portion) OCED eutrophication project: Nutrient loading-lake response relationships and trophic state indices. EPA 600/3-78-008, 454 pp. Retrieved March 1, 2023, from

  • Shannon, C. E. (2001). A mathematical theory of communication. ACM SIGMOBILE Mobile Computing and Communications Review, 5(1), 3–55.

    Article  Google Scholar 

  • Shortle, J. S., Abler, D. G., & Ribaudo, M. (2001). Agriculture and water quality: The issues. In Environmental policies for agricultural pollution control (pp. 1–18). CABI Publishing Wallingford UK.

  • Sinnadurai, S. (1973). Shallot farming in Ghana. Economic Botany, 438–441.

  • Smith, V. H. (2003). Eutrophication of freshwater and coastal marine ecosystems a global problem. Environmental Science and Pollution Research, 10, 126–139.

    Article  CAS  Google Scholar 

  • Smith, V. H., Joye, S. B., & Howarth, R. W. (2006). Eutrophication of freshwater and marine ecosystems. Limnology and oceanography, 51(1part2), 351–355.

  • Srichandan, S., Kim, J. Y., Bhadury, P., Barik, S. K., Muduli, P. R., Samal, R. N., Pattnaik, A. K., & Rastogi, G. (2015). Spatiotemporal distribution and composition of phytoplankton assemblages in a coastal tropical lagoon: Chilika, India. Environmental Monitoring and Assessment, 187, 1–17.

    Article  CAS  Google Scholar 

  • Stephan, C. E., Mount, D. I., Hansen, D. J., Gentile, J., Chapman, G. A., & Brungs, W. A. (1985). Guidelines for deriving numerical national water quality criteria for the protection of aquatic organisms and their uses. US Environmental Protection Agency Washington, DC.

  • Tu, J. (2011). Spatial and temporal relationships between water quality and land use in northern Georgia, USA. Journal of Integrative Environmental Sciences, 8(3), 151–170.

    Article  Google Scholar 

  • Zhou, Y., Obenour, D. R., Scavia, D., Johengen, T. H., & Michalak, A. M. (2013). Spatial and temporal trends in Lake Erie hypoxia, 1987–2007. Environmental Science & Technology, 47(2), 899–905.

    Article  CAS  Google Scholar 

Download references


We wish to thank the staff of the Department of Marine and Fisheries Sciences, especially, Mr. Mario Charles Boateng for their support during the entire duration of the project. We are greatly indebted to Mr. Bright Mawunyo Adzagba of Keta Ramsar & Center for Sea Turtle and Mangrove Conservation for supporting us during our field trips.


This research was funded by the Organization for Women in Sciences for the Developing World (OWSD) through UNESCO-OWSD Early Career Grant No. 4500406716.

Author information

Authors and Affiliations



Edem Mahu designed and supervised the study received funding, participated in field sampling and data analysis, and wrote the main manuscript. Priscilla Danso participated in sampling, data collection, and analysis, and wrote the main manuscript. Maurice Oti Edusei prepared figures. Kweku Amoako Atta deGraft-Johnson supervised the study. All authors reviewed the manuscript.

Corresponding author

Correspondence to Edem Mahu.

Ethics declarations

Ethical approval

All authors have read and understood and have complied as applicable with the statement on “Ethical responsibilities of Authors” as found in the Instructions for Authors.

Conflict of interest

The authors no competing interests.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Mahu, E., Danso, P., Edusei, M.O. et al. Impact of agricultural practices on ecosystem health of lagoons: a case study of the Keta Lagoon Complex in Ghana, West Africa. Environ Monit Assess 195, 622 (2023).

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: