Sources

Every paper behind the briefing

Each entry links to the publisher's page through its DOI. Where a figure from the paper appears in the briefing, the figure number is noted.

Sediment and the catchment

  1. Dutton, C.L., Anisfeld, S.C. & Ernstberger, H. (2013) A novel sediment fingerprinting method using filtration: application to the Mara River, East Africa. Journal of Soils and Sediments 13:1708–1723. doi:10.1007/s11368-013-0725-z

    Source of the 51% / 34% / 5% sediment apportionment.

  2. Dutton, C.L., Subalusky, A.L., Anisfeld, S.C., Njoroge, L., Rosi, E.J. & Post, D.M. (2018) The influence of a semi-arid sub-catchment on suspended sediments in the Mara River, Kenya. PLOS ONE 13:e0192828. doi:10.1371/journal.pone.0192828

    Basin map (Fig 1) and the gauged sediment flux (Fig 7).

  3. Dutton, C.L., Subalusky, A.L., Hill, T.D., Aleman, J.C., Rosi, E.J., Onyango, K.B., Kanuni, K., Cousins, J.A., Staver, A.C. & Post, D.M. (2019) A 2000-year sediment record reveals rapidly changing sedimentation and land use since the 1960s in the Upper Mara-Serengeti Ecosystem. Science of the Total Environment 664:148–160. doi:10.1016/j.scitotenv.2019.01.421

    Wetland cores, mercury and nitrogen isotope records (Fig 7); basin area and population figures.

The migration, carcasses and scavengers

  1. Subalusky, A.L., Dutton, C.L., Rosi, E.J. & Post, D.M. (2017) Annual mass drownings of the Serengeti wildebeest migration influence nutrient cycling and storage in the Mara River. PNAS 114:7647–7652. doi:10.1073/pnas.1614778114

    Drowning counts and nutrient loads (Fig 3); scavenger nutrient removal (Fig 2E).

  2. Subalusky, A.L., Dutton, C.L., Rosi, E.J., Puth, L.M. & Post, D.M. (2020) A river of bones: wildebeest skeletons leave a legacy of mass mortality in the Mara River, Kenya. Frontiers in Ecology and Evolution 8:31. doi:10.3389/fevo.2020.00031

    Soft tissue and bone decomposition rates (Fig 2).

  3. Handler, K.S., Subalusky, A.L., Kendall, C.J., Dutton, C.L., Rosi, E.J. & Post, D.M. (2021) Temporal resource partitioning of wildebeest carcasses by scavengers after riverine mass mortality events. Ecosphere 12:e03326. doi:10.1002/ecs2.3326

    Scavenger assemblage at mass drownings (Fig 2).

Hippos, loading and oxygen

  1. Subalusky, A.L., Dutton, C.L., Rosi-Marshall, E.J. & Post, D.M. (2015) The hippopotamus conveyor belt: vectors of carbon and nutrients from terrestrial grasslands to aquatic systems in sub-Saharan Africa. Freshwater Biology 60:512–525. doi:10.1111/fwb.12474

    Loading model (Fig 2) and the captive mass-balance trial behind the 8.7 kg per hippo per day figure.

  2. Dutton, C.L., Subalusky, A.L., Hamilton, S.K., Rosi, E.J. & Post, D.M. (2018) Organic matter loading by hippopotami causes subsidy overload resulting in downstream hypoxia and fish kills. Nature Communications 9:1951. doi:10.1038/s41467-018-04391-6

    Continuous dissolved oxygen record and the flushing flows (Fig 1).

  3. Dutton, C.L., Subalusky, A.L., Hamilton, S.K., Bayer, E.C., Njoroge, L., Rosi, E.J. & Post, D.M. (2021) Alternative biogeochemical states of river pools mediated by hippo use and flow variability. Ecosystems 24:284–300. doi:10.1007/s10021-020-00518-3

    The Hippo Subsidy Index (Fig 2), pool chemistry (Fig 4), and the management conclusion quoted in the briefing.

  4. Dutton, C.L., Subalusky, A.L., Sanchez, A., Estrela, S., Lu, N., Hamilton, S.K., Njoroge, L., Rosi, E.J. & Post, D.M. (2021) The meta-gut: community coalescence of animal gut and environmental microbiomes. Scientific Reports 11:23117. doi:10.1038/s41598-021-02349-1

    Shared active taxa between hippo gut and pool sediment (Fig 1).

Silicon, livestock and environmental flows

  1. Schoelynck, J., Subalusky, A.L., Struyf, E., Dutton, C.L., Unzué-Belmonte, D., Van de Vijver, B., Post, D.M., Rosi, E.J., Meire, P. & Frings, P. (2019) Hippos (Hippopotamus amphibius): the animal silicon pump. Science Advances 5:eaav0395. doi:10.1126/sciadv.aav0395

    Silicon mass balance (Fig 1) and the 36 hippos per river kilometre figure.

  2. Masese, F.O., Kiplagat, M.J., González-Quijano, C.R., Subalusky, A.L., Dutton, C.L., Post, D.M. & Singer, G.A. (2020) Hippopotamus are distinct from domestic livestock in their resource subsidies to and effects on aquatic ecosystems. Proceedings of the Royal Society B 287:20193000. doi:10.1098/rspb.2019.3000

    Cattle against hippo loading inside and outside the reserve.

  3. McClain, M.E., Subalusky, A.L., Anderson, E.P., Dessu, S.B., Melesse, A.M., Ndomba, P.M., Mtamba, J.O.D., Tamatamah, R.A. & Mligo, C. (2014) Comparing flow regime, channel hydraulics, and biological communities to infer flow–ecology relationships in the Mara River of Kenya and Tanzania. Hydrological Sciences Journal 59:801–819. doi:10.1080/02626667.2013.853121

    Environmental flow assessment, the proposed dams and the Reserve Flow at Q95.

Where the Mara work has gone next

These papers generalise the Mara findings beyond the basin. They are not covered in the briefing itself.

  1. Blaszczak, J.R., Koenig, L.E., Mejia, F.H., Gómez-Gener, L., Dutton, C.L., et al. (2023) Extent, patterns, and drivers of hypoxia in the world's streams and rivers. Limnology and Oceanography Letters 8:453–463. doi:10.1002/lol2.10297

    Puts the Mara's oxygen crashes in a global context.

  2. Dutton, C.L., Goeckner, A., Goldwire, T., Grupstra, C.G.B., Houghtaling, D., Nonnamaker, L.E. & Subalusky, A.L. (2026) Bioreactors on the move: how animals contribute to microbial community coalescence and shape ecosystem function. Environmental Microbiology. doi:10.1111/1462-2920.70291

    The meta-gut framework generalised across animals and ecosystems.

  3. Subalusky, A.L., Dutton, C.L. & McCleery, R.A. (2026) The ripple effect of surface water on dryland ecosystems. Trends in Ecology & Evolution. doi:10.1016/j.tree.2026.07.004

    How small surface waters, the hippo pools among them, propagate through dryland ecosystems.