Atlantic Coast Rivers of the Southeastern United States

Smock, Leonard A.; Wright, Anne B.; Benke, Arthur C.

doi:10.1016/b978-012088253-3/50006-7

Cited by 20 publications

(21 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The James River is a tributary of Chesapeake Bay with a length of 545 km and a drainage area of 26,165 km 2 (Smock et al 2005). The watershed is comprised of 71% forest, 7% agriculture, 5% urban and 3% wetland (Smock et al 2005).…”

Section: Study Sitementioning

confidence: 99%

See 1 more Smart Citation

Factors Determining the Location of the Chlorophyll Maximum and the Fate of Algal Production within the Tidal Freshwater James River

Bukaveckas

Barry

Beckwith

et al. 2011

Estuaries and Coasts

View full text Add to dashboard Cite

Longitudinal variation in factors affecting phytoplankton production were analyzed to better understand the mechanisms that cause the formation of a chlorophyll maximum within the tidal freshwater James River. Phytoplankton production was two-to threefold higher in the region where persistent elevated chlorophyll concentrations occurred. Near this site, the morphology of the James transitions from a narrow, deep channel to a broad expanse with shallow areas adjoining the main channel. Shallower depths resulted in greater average irradiance within the water column and suggest that release from light limitation was the principal factor accounting for the location of the chlorophyll maximum. Grazing rates were low indicating that little of the algal production was directly consumed by zooplankton. Low exploitation by zooplankton was attributed to poor food quality due to high concentrations of non-algal particulate matter and potential presence of cyanobacteria. Metabolism data suggest that two thirds of net primary production was respired in the vicinity of the chlorophyll maximum and one third was exported via fluvial and tidal advection. Comparison of water column and ecosystem metabolism indicates that the bulk of respiration occurred within the sediments and that sedimentation was the dominant loss process for phytoplankton.

show abstract

Section: Study Sitementioning

confidence: 99%

“…The watershed is comprised of 71% forest, 7% agriculture, 5% urban and 3% wetland (Smock et al 2005). Discharge during the period of study (April-November 2007) was 96 m 3 s −1 and below the 10-year average for these months (155 m 3 s −1 ; USGS 2008).…”

Section: Study Sitementioning

confidence: 99%

Factors Determining the Location of the Chlorophyll Maximum and the Fate of Algal Production within the Tidal Freshwater James River

Bukaveckas

Barry

Beckwith

et al. 2011

Estuaries and Coasts

View full text Add to dashboard Cite

show abstract

“…Snags are a common invertebrate habitat in low‐gradient rivers that meander within floodplain forests of the southeastern U.S. Coastal Plain (Smock, Wright & Benke, ). An early study on one such river (the Satilla) in southern Georgia demonstrated that snags were a hotspot for invertebrate diversity and production (Benke et al ., ).…”

Section: Introductionmentioning

confidence: 99%

High secondary production in a Coastal Plain river is dominated by snag invertebrates and fuelled mainly by amorphous detritus

Benke

Wallace

2014

Freshwater Biology

Self Cite

View full text Add to dashboard Cite

Summary The 2‐years production dynamics of major taxa (family/order) and functional feeding groups was synthesised from detailed production analyses previously published for all major invertebrate species/genera (retained by a 100 μm sieve) found on snags (submerged wood) in a sixth‐order south‐eastern U.S. Coastal Plain river. The trophic basis of this production and annual consumption of six food types were quantified. Invertebrate production (148 and 203 g dry mass m−2 year−1 of snag surfaces for the 2 years) was among the highest ever measured for a specific habitat in non‐polluted or unregulated rivers and was still relatively high when converted to overall area of the river bed (48 and 70 g m−2 year−1). Snag production constituted 73% of total main‐channel production (production from snag and river bed combined). Chironomidae (40–44% over the 2 years), Ephemeroptera (14–21%) and Trichoptera (25–31%) together represented the majority (88–93%) of the putative production of primary consumers on snags. Functional group analysis showed that fine filterers (26–36% over the 2 years), gatherers (36–44%) and macro‐filterers (21–25%) represented the majority of total invertebrate production. Production of predaceous insects (mostly Plecoptera, Odonata and Megaloptera) represented only 5–7% of the total. Production of the three major taxa and three major functional groups was remarkably consistent over 2 years of monthly sampling, despite strong seasonal variation in discharge/light/temperature and production of individual genera and families. Seventy‐nine per cent of production by primary consumers was supported by microbially enriched amorphous detritus, the major component of seston originating primarily from floodplain forests. Invertebrates consumed ˜357 g AFDM m−2 (river bed) year−1 of seston, 325 g m−2 year−1 of amorphous detritus and 20 g m−2 year−1 of diatoms. Dividing seston consumption by seston transport indicated that ˜67% of seston was consumed over 100 km of river length. Consumption was higher than autochthonous net primary production, supporting other evidence that terrestrially derived dissolved organic matter, incorporated via the microbial loop, is the main trophic basis of this riverine food web. Macro‐filtering hydropsychid caddisflies were omnivorous with > half their production from carnivory. Snag predators, including hydropsychids, consumed ˜60% (29 g m−2 year−1 of river bed) of invertebrate production (assumed to be from snags), leaving the remainder for emergence, downstream transport and consumption by fish.

show abstract

“…, Smock et al. ). In the absence of fish production and feeding data, however, their contribution to the trophic tangle could not be quantified.…”

Section: Discussionmentioning

confidence: 99%

“…Although 80+ fish species have been reported throughout the basin (e.g., Smock et al. ), no attempt was made to estimate fish production and include fishes in food webs.…”

Section: Methodsmentioning

confidence: 99%

River food webs: an integrative approach to bottom‐up flow webs, top‐down impact webs, and trophic position

Benke

2018

Ecology

Self Cite

View full text Add to dashboard Cite

The majority of food web studies are based on connectivity, top-down impacts, bottom-up flows, or trophic position (TP), and ecologists have argued for decades which is best. Rarely have any two been considered simultaneously. The present study uses a procedure that integrates the last three approaches based on taxon-specific secondary production and gut analyses. Ingestion flows are quantified to create a flow web and the same data are used to quantify TP for all taxa. An individual predator's impacts also are estimated using the ratio of its ingestion (I) of each prey to prey production (P) to create an I/P web. This procedure was applied to 41 invertebrate taxa inhabiting submerged woody habitat in a southeastern U.S. river. A complex flow web starting with five basal food resources had 462 flows >1 mg·m ·yr , providing far more information than a connectivity web. Total flows from basal resources to primary consumers/omnivores were dominated by allochthonous amorphous detritus and ranged from 1 to >50,000 mg·m ·yr . Most predator-prey flows were much lower (<50 mg·m ·yr ), but some were >1,000 mg·m ·yr . The I/P web showed that 83% of individual predator impacts were weak (<10%), whereas total predator impacts were often strong (e.g., 35% of prey sustained an impact >90%). Quantitative estimates of TP ranged from 2 to 3.7, contrasting sharply with seven integer-based trophic levels based on longest feeding chain. Traditional omnivores (TP = 2.4-2.9) played an important role by consuming more prey and exerting higher impacts on primary consumers than strict predators (TP ≥ 3). This study illustrates how simultaneous quantification of flow pathways, predator impacts, and TP together provide an integrated characterization of natural food webs.

show abstract

Atlantic Coast Rivers of the Southeastern United States

Cited by 20 publications

References 23 publications

Factors Determining the Location of the Chlorophyll Maximum and the Fate of Algal Production within the Tidal Freshwater James River

Factors Determining the Location of the Chlorophyll Maximum and the Fate of Algal Production within the Tidal Freshwater James River

High secondary production in a Coastal Plain river is dominated by snag invertebrates and fuelled mainly by amorphous detritus

River food webs: an integrative approach to bottom‐up flow webs, top‐down impact webs, and trophic position

Contact Info

Product

Resources

About