Terrestrial deposits on intertidal sandflats: sediment characteristics as indicators of habitat suitability for recolonising macrofauna

Cummings, Vonda J.; Thrush, Simon F.; Hewitt, Judi E.; Norkko, Alf; Pickmere, S.

doi:10.3354/meps253039

Cited by 38 publications

(29 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The slurry was slightly acidic (pH ≈4) upon application in the first experiment (probably due to the electronegativity of clay particles), but pH rose to 7 to 8 after 1 to 2 tidal cycles. Nevertheless, pH was neutralized with a base (aqueous sodium hydroxide) prior to application in subsequent experiments (see also Cummings et al 2003).Mar Ecol Prog SerPlots were spaced 10 m apart (from midpoint to midpoint) and were randomly positioned in rows running parallel to the shoreline in order to account for any confounding effects due to slight differences in tidal height and inundation. Three different experiments were performed, 2 of them initiated in spring (7 November 2000) and the third in mid-summer (16 January 2001).…”

mentioning

confidence: 99%

Terrestrially derived sediment: response of marine macrobenthic communities to thin terrigenous deposits

Lohrer

Thrush²,

Hewitt³

et al. 2004

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

Coastal marine habitats adjacent to catchments with encroaching human development are likely to experience increased sediment loadings in ensuing decades. Thus, sedimentary disturbance regimes in which coastal marine benthic communities have evolved may be shifting as depositional events exceeding critical thresholds become more frequent. To understand the threat posed by terrigenous sedimentation in an embayment with increasing urban development, we determined the thickness and frequency at which terrigenous sediment deposits begin to affect the benthos. We performed manipulative experiments involving layers of terrigenous sediment <1 cm thick in a variety of intertidal habitats in the Whitford embayment, North Island, New Zealand. Results of 3 separate experiments performed at 5 sites were largely consistent. While experimental plots were never completely defaunated, as little as 3 mm of the terrigenous material was sufficient to significantly alter macrobenthic community structure (measured after 10 d, relative to 0 mm controls). The direction of change was predominantly negative; the number of individuals and taxa declined as a result of sediment application, as did the densities of nearly every common species. Large bivalves were less affected than smaller ones, and deeper-dwelling species were less affected than ones at the sediment surface. With repeated applications of thin terrigenous layers (3 mm thickness, monthly over a 6 mo period), the sandflat sediments gradually became finer (clay volume % increased), and macrofaunal community composition progressively diverged from controls. To summarise, macrofauna were negatively affected by extremely small amounts of terrigenous sediment, and repeated depositional events did more damage than single ones. With increasing defoliation and excavation of catchment hillsides, the frequency of depositional events of a given intensity is likely to quicken, indicating an enhanced likelihood of macrofaunal disturbance and degradation in estuarine tidal flats. Management decisions that protect coastal catchments may partially ameliorate the threat to the benthos in coastal receiving waters.KEY WORDS: Land-use · Sediment impacts · Terrigenous sediment deposition · Marine benthos · Sandflat · Low intensity · High-frequency disturbance · Self-organized criticality Resale or republication not permitted without written consent of the publisherMar Ecol Prog Ser 273: [121][122][123][124][125][126][127][128][129][130][131][132][133][134][135][136][137][138] 2004 are reacting to and recovering from variously sized disturbances, perhaps of several types and intensities, dating back to various points in time (Connell 1978, Huston 1979, Yodzis 1986, Tokeshi 1999.With so many factors potentially influencing disturbance-recovery dynamics, ecologists have been forced to simplify their models and experimental investigations by focusing on specific circumstances. For example, studies of disturbance-recovery dynamics often begin with the complete defaunation of disturbed pat...

show abstract

mentioning

confidence: 99%

Terrestrially derived sediment: response of marine macrobenthic communities to thin terrigenous deposits

Lohrer

Thrush²,

Hewitt³

et al. 2004

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

show abstract

“…The characteristics of these deposits remained considerably distinct from those of the surrounding sandflat (e.g. lower sediment chlorophyll a, higher clay, silt, N and P content than ambient sediments; Cummings et al 2003), perhaps explaining why rapid recolonisation does not occur. In a companion experiment on the same sandflat, the macrofaunal community in 3 cm-thick terrestrial sediments was still very unstable in comparison to the ambient macrobenthic community 20 mo after the deposition of the terrestrial sediment .…”

Section: Introductionmentioning

confidence: 95%

Behavioural response of juvenile bivalves to terrestrial sediment deposits: implications for post-disturbance recolonisation

Cummings¹,

Thrush²

2004

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

In soft-sediment systems, terrestrial sediment deposits may result in a marked change in habitat and benthic community composition. We conducted a series of experiments to investigate the behavioural response of juveniles of 2 bivalve species common on New Zealand intertidal sandflats (Paphies australis and Macomona liliana) to terrestrial sediments. Both species are able to actively disperse as juveniles and do so in response to 'unfavourable' conditions. In the laboratory, we investigated the ability of these potential colonists to burrow into thin (0.5, 1.0 cm) surface and submerged terrestrial sediment layers, and their subsequent ability to burrow into natural sediments. Field experiments assessed their response to terrestrial sediments that had been 'aged' in the natural estuarine environment for different lengths of time (up to 1 mo). Exposure to terrestrial sediment treatments negatively affected both species, with fewer individuals burrowing into the terrestrial sediment treatments. In the laboratory, burrowing was slower in the 1 cm-thick surface layers than in the 0.5 cm-thick and submerged layers, and the subsequent burrowing rate in natural sand of individuals recovered from these treatments was similarly affected. This latter effect is important as it suggests that settlement by juvenile bivalves on terrestrial sediment deposits can have a lasting effect even if an individual is able to find a more suitable habitat at a later date. In the field, dispersal of M. liliana away from the terrestrial sediment treatments was reduced, even after the sediment had been 'aged' on the sandflat. Depending upon the extent and frequency of disturbance, terrestrial sediments are likely to have important effects on the population and community dynamics of mobile bivalve species, and at a wider scale than that of their immediate impact.

show abstract

“…Acute effects of sediments include smothering of benthic communities by slugs of fine terrigenous sediment brought down from the catchment during rainstorms, which results in mortality due to the anaerobic conditions that rapidly develop underneath the slug Thrush et al 2003a). Subsequent changes in sediment biogeochemistry and sediment food quality have been noted as factors limiting the recovery of affected areas (Cummings et al 2003). Thinner layers of sediment that are deposited more frequently and usually over greater areas than slugs may not directly cause mortality, but they do result in long-term effects on physiological condition and behaviour of macrofauna .…”

Section: Introductionmentioning

confidence: 99%

Catchment sediment load limits to achieve estuary sedimentation targets

Green

2013

New Zealand Journal of Marine and Freshwater Research

View full text Add to dashboard Cite

Limits are needed to manage the cumulative effects of sediments in estuaries. A method of calculating catchment sediment load limits to achieve estuary sedimentation targets is presented. The method is based on manipulating the sediment budget and takes advantage of the inherent complexity of the estuary and its connections to different sediment source regions in the catchment. In all but the simplest of cases, there is never just one way to achieve estuary sedimentation targets. This is where opportunity lies, for some ways of achieving targets will be better than others. Management can focus on finding sediment load limits that do not fail any sedimentation targets and that are achievable, affordable and efficient. The latter is expressed in terms of sacrificing capacity of the estuary to accommodate sediment in order that no sedimentation targets are failed. The method and underlying principles are demonstrated by application to Pāuatahanui Inlet, New Zealand.

show abstract

Terrestrial deposits on intertidal sandflats: sediment characteristics as indicators of habitat suitability for recolonising macrofauna

Cited by 38 publications

References 53 publications

Terrestrially derived sediment: response of marine macrobenthic communities to thin terrigenous deposits

Terrestrially derived sediment: response of marine macrobenthic communities to thin terrigenous deposits

Behavioural response of juvenile bivalves to terrestrial sediment deposits: implications for post-disturbance recolonisation

Catchment sediment load limits to achieve estuary sedimentation targets

Contact Info

Product

Resources

About