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Role of saltmarsh systems in estuarine trapping of microplastics. Sci Rep 2022; 12:15546. [PMID: 36109565 PMCID: PMC9477837 DOI: 10.1038/s41598-022-18881-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 08/22/2022] [Indexed: 11/09/2022] Open
Abstract
Saltmarshes are important natural ecosystems along many temperate (and other) coastlines. They stabilize sediments and act as biofilters for a range of industrial pollutants and, potentially, microplastics. Accumulation of microplastics along estuarine coastlines may be enhanced by the presence of saltmarsh species, as they offer better particle trapping efficiency than adjacent intertidal mudflats under prevailing flood and ebb tidal currents. However, the trapping efficiency of entire saltmarsh systems under varying flow conditions has not been widely assessed. While the effects of saltmarsh systems on water flow, and on sediment transport and trapping, have been relatively well studied, little is known about the contributions of saltmarsh halophytes, resident organisms and the associated saltmarsh sediments to the trapping of microplastics. To address this, a series of flume experiments were undertaken to examine transport and accumulation of Bakelite particles (~ 500 µm) and PVC nurdles (~ 5 mm) as model plastics in sub-sampled saltmarsh and intertidal mudflat monoliths. The results showed that saltmarsh systems influenced the hydrodynamics within and above the canopy, enhancing turbulence and shear stresses. With increasing flow velocities (≤ 0.51 m s−1), negligible quantities (2 \documentclass[12pt]{minimal}
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\begin{document}$$\times$$\end{document}× 10−4 mg L−1) of sediments and Bakelite particles were eroded and resuspended. The algal biogenic roughness from the mudflat, and the vegetative roughness from the Spartina plants on the saltmarsh, inhibited the transportation of the microplastics within the tested systems. Resident burrowing crabs (Carcinus maenas) promoted the burial, release and transport of microplastics. The results of this study provide evidence of the contributory roles of saltmarsh systems in the sequestration of microplastics and sediment stabilization. Estuarine saltmarsh systems can act as sinks for microplastics with enhanced burial from burrowing crabs under favourable flow conditions.
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Zhou Z, Bouma TJ, Fivash GS, Ysebaert T, van IJzerloo L, van Dalen J, van Dam B, Walles B. Thermal stress affects bioturbators' burrowing behavior: A mesocosm experiment on common cockles (Cerastoderma edule). THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 824:153621. [PMID: 35124053 DOI: 10.1016/j.scitotenv.2022.153621] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 12/23/2021] [Accepted: 01/29/2022] [Indexed: 06/14/2023]
Abstract
The intensity of marine heatwaves is increasing due to climate change. Heatwaves may affect macroinvertebrates' bioturbating behavior in intertidal areas, thereby altering the deposition-erosion balance at tidal flats. Moreover, small-scale topographic features on tidal flats can create tidal pools during the low tide, thus changing the heat capacity of tidal flats. These pools could then potentially operate as refuge environments during marine heatwaves. We studied behavior responses to heat waves using the well-known bioturbating cockle Cerastoderma edule as a model species. Different temperature regimes (i.e., fluctuating between 20 and 40 °C) and micro-topographies (i.e., presence vs. absence of tidal water pools) were mimicked in a mesocosm experiment with regular tidal regimes. Our results demonstrate that behavioral responses to heat stress strongly depend on the site-specific morphological features. Cockles covered by shallow water pools moved up when exposed to thermal stress, while burrowing deeper into the sediment in the absence of water pools. But in both cases, their migratory behavior increased under heat stress compared to regular ambient treatments. Moreover, long-term cumulative heat stress increased cockles' respiration rates and decreased their health conditions, causing mass mortality after four weeks of gradually increasing heat exposure. Overall, the present findings provide the first insights into how bioturbating behavior on tidal flats may change in response to global warming.
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Affiliation(s)
- Zhengquan Zhou
- NIOZ Royal Netherlands Institute for Sea Research, Department of Estuarine and Delta Systems, Utrecht University, Yerseke, the Netherlands; Faculty of Geosciences, Department of Physical Geography, Utrecht University, the Netherlands.
| | - Tjeerd J Bouma
- NIOZ Royal Netherlands Institute for Sea Research, Department of Estuarine and Delta Systems, Utrecht University, Yerseke, the Netherlands; Faculty of Geosciences, Department of Physical Geography, Utrecht University, the Netherlands; University of Applied Sciences, Vlissingen, the Netherlands
| | - Gregory S Fivash
- NIOZ Royal Netherlands Institute for Sea Research, Department of Estuarine and Delta Systems, Utrecht University, Yerseke, the Netherlands
| | - Tom Ysebaert
- NIOZ Royal Netherlands Institute for Sea Research, Department of Estuarine and Delta Systems, Utrecht University, Yerseke, the Netherlands; Wageningen Marine Research, Wageningen University and Research, PO Box 77, 4400, AB, Yerseke, the Netherlands
| | - Lennart van IJzerloo
- NIOZ Royal Netherlands Institute for Sea Research, Department of Estuarine and Delta Systems, Utrecht University, Yerseke, the Netherlands; Faculty of Geosciences, Department of Physical Geography, Utrecht University, the Netherlands
| | - Jeroen van Dalen
- NIOZ Royal Netherlands Institute for Sea Research, Department of Estuarine and Delta Systems, Utrecht University, Yerseke, the Netherlands
| | - Bas van Dam
- Faculty of Geosciences, Department of Physical Geography, Utrecht University, the Netherlands
| | - Brenda Walles
- Wageningen Marine Research, Wageningen University and Research, PO Box 77, 4400, AB, Yerseke, the Netherlands
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Xie D, Schwarz C, Kleinhans MG, Zhou Z, van Maanen B. Implications of Coastal Conditions and Sea-Level Rise on Mangrove Vulnerability: A Bio-Morphodynamic Modeling Study. JOURNAL OF GEOPHYSICAL RESEARCH. EARTH SURFACE 2022; 127:e2021JF006301. [PMID: 35860814 PMCID: PMC9285630 DOI: 10.1029/2021jf006301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 01/18/2022] [Accepted: 02/10/2022] [Indexed: 05/24/2023]
Abstract
Mangrove forests are valuable coastal ecosystems that have been shown to persist on muddy intertidal flats through bio-morphodynamic feedbacks. However, the role of coastal conditions on mangrove behavior remains uncertain. This study conducts numerical experiments to systematically explore the effects of tidal range, small wind waves, sediment supply and coastal slope on mangrove development under sea-level rise (SLR). Our results show that mangroves in micro-tidal conditions are more vulnerable because of the gentler coastal equilibrium slope and the limited ability to capture sediment, which leads to substantial mangrove landward displacement even under slow SLR. Macro-tidal conditions with large sediment supply promote accretion along the profile and platform formation, reducing mangrove vulnerability for slow and medium SLR, but still cause rapid mangrove retreat under fast SLR. Small wind waves promote sediment accretion, and exert an extra bed shear stress that confines the mangrove forest to higher elevations with more favorable inundation regimes, offsetting SLR impacts. These processes also have important implications for the development of new landward habitats under SLR. In particular, our experiments show that landward habitat can be created even with limited sediment supply and thus without complete infilling of the available accommodation space. Nevertheless, new accommodation space may be filled over time with sediment originating from erosion of the lower coastal profile. Consistent with field data, model simulations indicate that sediment accretion within the forest can accelerate under SLR, but the timing and magnitude of accretion depend non-linearly on coastal conditions and distance from the mangrove seaward edge.
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Affiliation(s)
- Danghan Xie
- Faculty of GeosciencesUtrecht UniversityUtrechtNetherlands
| | - Christian Schwarz
- Department of Civil EngineeringHydraulics and GeotechnicsKU LeuvenLeuvenBelgium
- Department of Earth and Environmental SciencesKU LeuvenLeuvenBelgium
| | | | - Zeng Zhou
- State Key Laboratory of Hydrology‐Water Resources and Hydraulic EngineeringHohai UniversityNanjingChina
| | - Barend van Maanen
- College of Life and Environmental SciencesUniversity of ExeterExeterUK
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Cozzoli F, Shokri M, Gomes da Conceição T, Herman PMJ, Hu Z, Soissons LM, Van Dalen J, Ysebaert T, Bouma TJ. Modelling spatial and temporal patterns in bioturbator effects on sediment resuspension: A biophysical metabolic approach. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 792:148215. [PMID: 34465034 DOI: 10.1016/j.scitotenv.2021.148215] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 05/27/2021] [Accepted: 05/29/2021] [Indexed: 06/13/2023]
Abstract
Tidal flats are biogeomorphic landscapes, shaped by physical forces and interaction with benthic biota. We used a metabolic approach to assess the overarching effect of bioturbators on tidal landscapes. The benthic bivalve common cockle (Cerastoderma edule) was used as model organism. The effect of C. edule on sediment resuspension was approximated as a function of the overall population metabolic rate per unit of area. We combined i) laboratory observations on how C. edule affect sediment resuspension along gradients of bioturbation activity, sediment cohesiveness and hydrodynamic force with ii) spatial data on the natural distribution of intertidal C. edule populations. This allowed us to build an integrated model of the C. edule effect on sediment resuspension along the tidal gradient. Owing to the temperature dependence of metabolic rate, the model also accounted for seasonal variation in bioturbators activity. Laboratory experiments indicated that sediment resuspension is positively related to the metabolic rate of the C. edule population especially in cohesive sediments. Based on this observation, we predicted a clear spatial and seasonal pattern in the relative importance of C. edule contribution to sediment resuspension along a tidal transect. At lower elevations, our model indicates that hydrodynamics overrules biotic effects; at higher elevations, inter-tidal hydrodynamics should be too low to suspend bioturbated sediments. The influence of C. edule on sediment resuspension is expected to be maximal at the intermediate elevation of a mudflat, owing to the combination of moderate hydrodynamic stress and high bioturbator activity. Also, bio-mediated sediment resuspension is predicted to be particularly high in the warm season. Research into metabolic dependency of bio-mediated sediment resuspension may help to place phenomenological observations in the broader framework of metabolic theories in ecology and to formulate general expectations on the coastal ecosystem functioning.
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Affiliation(s)
- Francesco Cozzoli
- Research Institute on Terrestrial Ecosystems (IRET) - National Research Council of Italy (CNR), 00015 Monterotondo Scalo (Roma), Italy; Department of Biological and Environmental Sciences and Technologies (DiSTeBA), University of Salento, 73100 Lecce, Italy.
| | - Milad Shokri
- Department of Biological and Environmental Sciences and Technologies (DiSTeBA), University of Salento, 73100 Lecce, Italy
| | - Tatiana Gomes da Conceição
- Department of Estuarine and Delta Systems. Royal Netherlands Institute of Sea Research (NIOZ). 4401 NT Yerseke, The Netherlands
| | - Peter M J Herman
- Department of Hydraulic Engineering, Delft University of Technology, 2628 CN, Delft, The Netherlands; Deltares, 2600 MH, Delft, The Netherlands
| | - Zhan Hu
- School of Marine Science, Sun Yat-Sen University, and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), 519082 Zhuhai, China; Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, 510275 Guangzhou, China; Pearl River Estuary Marine Ecosystem Research Station, Ministry of Education, 519082 Zhuhai, China.
| | - Laura M Soissons
- ESE, Ecology and Ecosystem Health, Agrocampus-Ouest, INRAE, 35042 Rennes, France
| | - Jeroen Van Dalen
- Department of Estuarine and Delta Systems. Royal Netherlands Institute of Sea Research (NIOZ). 4401 NT Yerseke, The Netherlands
| | - Tom Ysebaert
- Department of Estuarine and Delta Systems. Royal Netherlands Institute of Sea Research (NIOZ). 4401 NT Yerseke, The Netherlands; Wageningen Marine Research, Wageningen University and Research, P.B. 77, 4400 AB Yerseke, The Netherlands
| | - Tjeerd J Bouma
- Department of Estuarine and Delta Systems. Royal Netherlands Institute of Sea Research (NIOZ). 4401 NT Yerseke, The Netherlands; Faculty of Geosciences, Department of Physical Geography, Utrecht University, 3584 CS Utrecht, the Netherlands; HZ University of Applied Sciences, 4382 NW Vlissingen, The Netherlands
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