Wind-driven sediment suspension controls light availability in a shallow coastal lagoon

Lawson, Sarah; Wiberg, Patricia L.; McGlathery, Karen J.; Fugate, David C.

doi:10.1007/bf02782971

Cited by 157 publications

(186 citation statements)

References 43 publications

Supporting

Mentioning

179

Contrasting

Order By: Relevance

“…This is consistent with the idea that this process is episodic, opportunistic, and slow. While the southern Virginia coastal bays have good water quality and can support seagrass expansion (Lawson et al 2007;www1.vcrlter.virginia.edu/home1/? q=data_wq), coastal bays to the north are experiencing large declines in seagrass primarily due to water quality (Short et al 2006) and thus may have insufficient effective population size and number of propagules which could limit the long-term capacity for natural recruitment.…”

Section: Discussionmentioning

confidence: 99%

“…While many populations slowly recovered from the impact of this disease, including populations in the nearby Chesapeake Bay (Cottam & Munro 1954;Orth & Moore 1984), seagrass populations in the coastal bays of Virginia remained locally extinct for over 60 years (Orth et al 2006). Small naturally recovered patches of seagrass were found in the mid 1990s, and long-term water quality monitoring (www1.vcrlter.virginia.edu/home1/?q=data_wq) and modelling of light availability (Lawson et al 2007) suggested that this area could support seagrass. Recovery was probably limited by a lack of propagules .…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Restoration recovers population structure and landscape genetic connectivity in a dispersal‐limited ecosystem

2013

View full text Add to dashboard Cite

Summary1. Ecological restoration assists the recovery of degraded ecosystems; however, restoration can have deleterious effects such as outbreeding depression when source material is not chosen carefully and has non-local adaptations. 2. We surveyed 23 eelgrass (Zostera marina L.) populations along the North American Atlantic coast to evaluate genetic structure and connectivity among restored and naturally recruited populations. 3. While populations along the North America Atlantic coast were genetically distinctive, significant migration was detected among populations. All estimates of connectivity (F ST , migration rate base on rare alleles, and Bayesian modelling) showed a general north to south pattern of migration, corresponding to the typical long-shore currents in this region. 4. Individual naturally recruited meadows in the Virginia coastal bays appear to be the result of dispersal from different meadows north of the region. This supports the hypothesis that recruitment into this region is typically a slow, episodic process rather than a permanent, continuous connection between the populations. 5. While natural recovery of populations that were catastrophically lost in the 1930s has been slow, large-scale seed-based restoration has been very successful at quickly restoring landscape-scale areal coverage (over 1600 ha in just 10 years). Our results show that restoration was also successful at restoring meadows with high genetic diversity. Naturally recruited meadows were less diverse and exhibited signs of genetic drift. 6. Synthesis. Our analyses demonstrate that metapopulation dynamics are important to the natural recovery of seagrass ecosystems that have experienced catastrophic loss over large spatial scales; however, natural recovery processes are slow and inefficient at recovering genetic diversity and population structure when recruitment barriers exist, such as a limited seed source. Seed-based restoration provides a greater abundance of propagules, rapidly facilitates the recovery of populations with higher genetic diversity, and when seed sources are chosen carefully protects regional genetic structure. Firstorder estimates indicated that the genetic diversity achieved by active restoration in 10 years would have otherwise taken between 125 and 185 years to achieve through natural recruitment events.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Restoration recovers population structure and landscape genetic connectivity in a dispersal‐limited ecosystem

2013

View full text Add to dashboard Cite

show abstract

“…Marsh vegetation on the salt marshes is dominated by Spartina alterniflora, with an average stem height of 30 cm and a height range between 50 and 100 cm. The shallow depths of the VCR make lagoon-bottom sediment (D 50 ≈ 63 mm with sorting coefficient (D 84 /D 50 ) 1/2 ≈ 2) susceptible to wind-driven waves and currents, thus promoting sediment resuspension [Lawson et al, 2007;Lawson, 2004] tides alone are generally insufficient to resuspend sediment from the lagoon bottom.…”

Section: Site Descriptionmentioning

confidence: 99%

“…Herein, we let k b = 2D 90 [e.g., Kamphuis, 1975], so that equation (9) estimates the skin friction stress, and set D 90 = 0.25 mm based on grain size data from Hog Island Bay [Lawson, 2004]. The wave number k can be determined from the dispersion equation derived from linear wave theory:…”

Section: Wave Energy and Bottom Shear Stressesmentioning

confidence: 99%

“…Two distinct erosional mechanisms are associated with wind waves. Wave-generated shear stresses, combined with tidal currents, are the main mechanism responsible for sediment resuspension on tidal flats [Carniello et al, 2005;Fagherazzi et al, 2006Fagherazzi et al, , 2007Marani et al, 2007], and regulate both sediment concentration in the water column (and hence light availability at the bed) [e.g., Lawson et al, 2007] and sediment export to salt marshes and to the ocean [Mariotti and Fagherazzi, 2010]. Waves impacting salt marsh boundaries produce intermittent forces that promote marsh edge erosion and salt marsh regression.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Influence of storm surges and sea level on shallow tidal basin erosive processes

et al. 2010

Self Cite

View full text Add to dashboard Cite

[1] The finite-element model WWTM is applied to a system of lagoons at the Virginia Coast Reserve, USA. The model solves the shallow water equations to compute tidal fluxes, and is equipped with a wave propagation module to calculate wave height during local wind events. The model is validated using measured water elevations, wave heights, and periods at five locations within the lagoon system. Scenarios with different wind conditions, storm surges, and relative sea level are simulated. Results are analyzed in terms of bottom shear stresses on the tidal flats, a measure of sediment resuspension potential, and total wave energy impacting the marsh boundaries, which is the chief process driving lateral marsh erosion. Results indicate that wave energy at the marsh boundaries is more sensitive to wind direction than are bottom shear stresses. Wave energy on marsh boundaries and bottom shear stresses on the tidal flats increase with sea level elevation, with the former increasing almost ten times more than the latter. Both positive and negative feedbacks between wave energy at the boundaries and bottom shear stresses are predicted, depending on the fate of the sediments eroded from the salt marsh boundaries.

show abstract

Evaluation of sediment properties using wind and turbidity observations in the shallow tidal areas of the Venice Lagoon

2014

View full text Add to dashboard Cite

Sediment deposition and erosion by wind waves and tidal currents, mediated by bed sediment properties and by biostabilization/bioturbation, are key processes governing the dynamics of intertidal geomorphology. Here we develop and apply a method to estimate bed sediment properties, such as the settling velocity and the critical stress for erosion, providing a measure of the response of the system to the actual wave/tidal forcing. The method obtains estimates of sediment properties indirectly, by solving a sediment mass conservation equation for the water column, after explicitly modeling wave‐ and current‐induced bottom shear stresses. We apply this approach using meteorological, tidal, and turbidimetric data from a network of sensors in the Venice Lagoon, yielding estimates which compare favorably with existing observations of sediment properties. Advantages of the method are that it does not interfere with the biological and physical status of the sediment surface and that it makes use of commonly available weather and wave observations. The proposed method lends itself to the continuous monitoring of sediment parameters at the system scale with limited operational effort when the sediment suspended in the water column is mostly originated by local resuspension, such as in the case of wave‐dominated estuaries.

show abstract

Wind-driven sediment suspension controls light availability in a shallow coastal lagoon

Cited by 157 publications

References 43 publications

Restoration recovers population structure and landscape genetic connectivity in a dispersal‐limited ecosystem

Restoration recovers population structure and landscape genetic connectivity in a dispersal‐limited ecosystem

Influence of storm surges and sea level on shallow tidal basin erosive processes

Evaluation of sediment properties using wind and turbidity observations in the shallow tidal areas of the Venice Lagoon

Contact Info

Product

Resources

About