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. 2020 Feb 5;10(1):1913.
doi: 10.1038/s41598-020-58677-1.

Water Filtration by Burrowing Sandprawns Provides Novel Insights on Endobenthic Engineering and Solutions for Eutrophication

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Free PMC article

Water Filtration by Burrowing Sandprawns Provides Novel Insights on Endobenthic Engineering and Solutions for Eutrophication

Olivia Venter et al. Sci Rep. .
Free PMC article

Abstract

Managing coastal ecosystems and preserving socio-ecological functioning require a comprehensive understanding of ecological services provided by resident organisms. Here, we provide novel information on water-filtration activities of endobenthic sandprawns (Callichirus kraussi), which are key ecosystem engineers in South African coasts. We demonstrate experimentally that benthic engineering by sandprawns reduces phytoplankton biomass by roughly 50%. Using long-term estuarine data, we demonstrate similar reductions in phytoplankton biomass (by roughly 70%) in sandprawn-dominated areas. Increased burrow wall chlorophyll-a relative to surface sediments that was evident in experiments suggests that pelagic filtration occurs through bi-directional water pumping and phytoplankton adsorption onto burrow walls. Our findings expand understanding of the ecological relevance of sandprawns and functionally similar organisms, the mechanisms by which they engineer ecosystems and their role in mediating coastal bentho-pelagic coupling. Our findings also highlight the potential for deposit-feeders to be used as nature-based solutions to counter coastal eutrophication.

Conflict of interest statement

We declare that the authors have no competing interests as defined by Nature Publishing Group, or other interests that might be perceived to influence the results and/or discussion reported in this paper.

Figures

Figure 1
Figure 1
Map of the Zandvlei Estuary showing its geographical location with in South Africa (inset), position of sampling sites (1–6) and key features. Site 5 is located within a sandprawn-dominated biotope in the lower reaches, while Site 6 is located within a canalised region in which sandprawns are absent. Dashed arrow denotes the axial extent of the sandprawn biotope. Maps produced by Jessica Dawson and used with permission.
Figure 2
Figure 2
Inter-annual variability in in situ pelagic chl-a concentrations (means ± SD) among sites in the Zandvlei Estuary. Site 5 is located within a sandprawn-dominated biotope and Site 6 occurs in a canalised region in which sandprawns are absent. Water-column surface data are presented. SD is shown due to low data variance at Site 5.
Figure 3
Figure 3
Irregular sediment topography created by dense Callichirus kraussi (inset) populations in the sandprawn-dominated biotope in the Zandvlei Estuary. Holes on the sediment surface are burrow openings. The main image was taken 3 days after mouth opening, during which drainage into the Atlantic Ocean exposed most of the benthic habitat. Inset courtesy of Jessica Dawson, used with permission.
Figure 4
Figure 4
Temporal variability in pelagic chl-a concentrations (means ± SE) among sandprawn density treatments (0% = control; 50% = 6 sandprawns/mesocosm; 100% = 11 sandprawns/mesocosm). Surface and bottom data from the 2-week mesocosm experiment are shown.
Figure 5
Figure 5
Variation in chl-a concentrations (means ± SE) between burrow walls and sediment surface samples between control and 50% (6 sandprawns/mesocosm) and 100% (11 sandprawns/mesocosm) sandprawn density treatments. Data from the 2-week mesocosm experiment are shown.
Figure 6
Figure 6
Differences in suspended sediment loads (means ± SE) among sandprawn density treatments (0% = control; 50% = 6 sandprawns/mesocosm; 100% = 11 sandprawns/mesocosm). Surface data from the 2-week mesocosm experiment are shown.
Figure 7
Figure 7
Variability in in situ pelagic suspended sediment loads (means ± SD) between Site 5, which is located within a sandprawn-dominated biotope and Site 4, which is located upstream of the sandprawn-dominated biotope. Surface data are presented.

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References

    1. Costanza, R., Kemp, M. & Boynton, W. In Biodiversity Loss: Economic and Ecological Issues (eds. Perrings, C., Maler, K.G., Folke, C., Holling, C.S. & Jansson, B.O.) 84–126 (Cambridge University Press, 1995).
    1. Burke, L. et al. Coastal ecosystems (World Resources Institute, 2001).
    1. Sheaves M, Baker R, Nagelkerken I, Connolly RM. True value of estuarine and coastal nurseries for fish: incorporating complexity and dynamics. Estuar. Coast. 2015;38:401–414. doi: 10.1007/s12237-014-9846-x. - DOI
    1. Heck KL, et al. Trophic transfers from seagrass meadows subsidise diverse marine and terrestrial consumers. Ecosyst. 2008;11:1198–1210. doi: 10.1007/s10021-008-9155-y. - DOI
    1. Nagelkerken I, Sheaves M, Baker R, Connolly R. The seascape nursery: a novel spatial approach to identify and manage nurseries for coastal marine fauna. Fish Fish. 2014;16:362–371. doi: 10.1111/faf.12057. - DOI
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