Sediment transport and siltation of brown trout (Salmo trutta L.) spawning gravels in chalk streams

Acornley, R. M.; Sear, David

doi:10.1002/(sici)1099-1085(19990228)13:3<447::aid-hyp749>3.0.co;2-g

Cited by 127 publications

(85 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Heppell et al 2009; 66,800 g m −2 ) while low values are found in small urbanised catchments (e.g. West Midlands, Lawler et al 2006;50-110 g m −2 ) and chalk streams (Acornley and Sear 1999). In the upper Ehen, average storage ranged from 224 (T1) to 907 g m −2 (T9) and included all particles between 0.012 and 2 mm.…”

Section: In-channel Sediment Storagementioning

confidence: 97%

See 1 more Smart Citation

Asynchronicity of fine sediment supply and its effects on transport and storage in a regulated river

et al. 2018

View full text Add to dashboard Cite

Purpose A disconnected ephemeral tributary was reconnected to the regulated River Ehen (NW England) as part of a river restoration initiative, providing a renewed delivery of sediment to a highly stable and armoured channel. This paper (1) assesses spatial and temporal dynamics of suspended and stored sediments in the Ehen, (2) characterises the composition of stored sediment, (3) develops fine sediment budgets for downstream river reaches, and (4) assesses the controls on the storage of fine sediment in the riverbed. Materials and methods A 3-km study section in the upper part of the River Ehen was divided into two reaches. Suspended sediments were monitored at the downstream limits of each reach over a 2-year period. In-channel storage was measured in three morphological units within the upper reach, on 13 occasions over the same period. Samples were used to assess changes in volumes of stored fine sediment, as well as the grain sizes and organic content of the material. A time-lapse camera facing the confluence of the tributary was used to conceptualise different flow scenarios. These scenarios reflect the degree of synchronicity between flows in the main-stem and those in the tributary. Fine sediment budgets were developed for each reach to assess the relative contribution of different sources of sediment. Results and discussion The reconnection significantly affected suspended sediment loads in the Ehen. Bed storage increased twofold, with changes most evident in the slow-flowing morphological unit. Changes in the composition of stored sediment were less marked than changes in the quantity of material. Changes in bed storage were controlled by the degree of synchronicity between flows in the Ehen and those in the newly reconnected tributary. Results show that three generalised flow scenarios occur, with total asynchronicity between flows in the tributary and the Ehen being responsible for the main episodes of fine sediment deposition. Overall, the estimated sediment budgets provide insights into the importance of non-perennial sources of sediment in supply-limited systems such as the Ehen. Although bed storage values are within the range of those published for UK rivers, the increase observed since the reconnection, together with the persistence of a static pavement, highlights the ecologically critical conditions of the regulated main-stem River Ehen. Conclusions Intermittent sources control fine sediment transport dynamics in the upper River Ehen. In this regulated river, ongoing deposition associated with increased low-and medium-sized flow events exerts more of a control on bed storage than large but rare floods. Management actions to limit delivery of material from lateral sources could help prevent further deterioration of habitat conditions for biota sensitive to fine sediment. Given the ongoing adjustment in the newly reconnected tributary, continued monitoring is needed to capture further morphosedimentary response in the main-stem.

show abstract

Section: In-channel Sediment Storagementioning

confidence: 97%

“…Acornley and Sear 1999;Walling and Amos 1999) and sometimes in summer (e.g. Walling et al 2003;Collins and Walling 2007a, b).…”

Section: In-channel Sediment Storagementioning

confidence: 99%

Asynchronicity of fine sediment supply and its effects on transport and storage in a regulated river

et al. 2018

View full text Add to dashboard Cite

show abstract

“…Torrential rain is widely believed to considerably contribute to sediment erosion (Summer 1989;Acornley and Sear 1999;Fraser et al 1999;Descroix and Gautier 2002). Additionally, both droughts followed by heavy rain events and long consecutive rain events on already saturated soil can trigger erosion; the latter at an even higher extent than single day heavy rainfall events (Prasuhn 2003).…”

Section: Effects Of Changes In Precipitation Patternsmentioning

confidence: 99%

Climate and land-use changes affecting river sediment and brown trout in alpine countries—a review

Scheurer

Alewell

Bänninger

et al. 2008

Environ Sci Pollut Res

View full text Add to dashboard Cite

Background, aim, and scope Catch decline of freshwater fish has been recorded in several countries. Among the possible causes, habitat change is discussed. This article focuses on potentially increased levels of fine sediments going to rivers and their effects on gravel-spawning brown trout. Indications of increased erosion rates are evident from land-use change in agriculture, changes in forest management practices, and from climate change. The latter induces an increase in air and river water temperatures, reduction in permafrost, changes in snow dynamics and an increase in heavy rain events. As a result, an increase in river sediment is likely. Suspended sediment may affect fish health and behaviour directly. Furthermore, sediment loads may clog gravel beds impeding fish such as brown trout from spawning and reducing recruitment rates. To assess the potential impact on fine sediments, knowledge of brown trout reproductive needs and the effects of sediment on brown trout health were evaluated. Approach We critically reviewed the literature and included results from ongoing studies to answer the following questions, focusing on recent decades and rivers in alpine countries.-Have climate change and land-use change increased erosion and sediment loads in rivers? -Do we have indications of an increase in riverbed clogging?-Are there indications of direct or indirect effects on brown trout from increased suspended sediment concentrations in rivers or from an increase in riverbed clogging?Results Rising air temperatures have led to more intensive precipitation in winter months, earlier snow melt in spring, and rising snow lines and hence to increased erosion. Intensification of land use has supported erosion in lowland and prealpine areas in the second half of the twentieth century. In the Alps, however, reforestation of abandoned land at high altitudes might reduce the erosion risk while intensification on the lower, more easily accessible slopes increases erosion risk. Data from laboratory experiments show that suspended sediments affect the health and behaviour of fish when available in high amounts. Point measurements in large rivers indicate no common lethal threat and suspended sediment is rarely measured continuously in small rivers. However, effects on fish can be expected under environmentally relevant conditions. River bed clogging impairs the reproductive performance of gravel-spawning fish. Discussion Overall, higher erosion and increased levels of fine sediment going into rivers are expected in future. Additionally, sediment loads in rivers are suspected to have considerably impaired gravel bed structure and brown trout spawning is impeded. Timing of discharge is put forward and is now more likely to affect brown trout spawning than in previous decades. Conclusions Reports on riverbed clogging from changes in erosion and fine sediment deposition patterns, caused by climate change and land-use change are rare. This review identifies both a risk of increases in climate erosive forces and fine sedi...

show abstract

“…Again, these concentrations are relatively low. Acornley and Sear (1999) assessed 25 to 40 % C org in the SS during low flows in summer and 15 to 20 % during high flows in autumn in two rivers in Hampshire, England, which were also brown trout spawning habitats. The relatively low C org concentrations could partly be due to an instrumental bias of the SS samplers.…”

Section: Spatial and Temporal Dynamics Of C Org In Sedimentsmentioning

confidence: 99%

Organic matter dynamics and stable isotope signature as tracers of the sources of suspended sediment

Wildhaber¹,

Liechti²,

Alewell³

2012

Biogeosciences

View full text Add to dashboard Cite

Abstract. Suspended sediment (SS) and organic matter in rivers can harm brown trout Salmo trutta by affecting the health and fitness of free swimming fish and by causing siltation of the riverbed. The temporal and spatial dynamics of sediment, carbon (C), and nitrogen (N) during the brown trout spawning season in a small river of the Swiss Plateau were assessed and C isotopes as well as the C/N atomic ratio were used to distinguish autochthonous and allochthonous sources of organic matter in SS loads. The visual basic program IsoSource with 13 C tot and 15 N as input isotopes was used to quantify the temporal and spatial sources of SS. Organic matter concentrations in the infiltrated and suspended sediment were highest during low flow periods with small sediment loads and lowest during high flow periods with high sediment loads. Peak values in nitrate and dissolved organic C were measured during high flow and high rainfall, probably due to leaching from pasture and arable land. The organic matter was of allochthonous sources as indicated by the C/N atomic ratio and δ 13 C org . Organic matter in SS increased from up-to downstream due to an increase of pasture and arable land downstream of the river. The mean fraction of SS originating from upper watershed riverbed sediment decreased from up to downstream and increased during high flow at all measuring sites along the course of the river. During base flow conditions, the major sources of SS are pasture, forest and arable land. The latter increased during rainy and warmer winter periods, most likely because both triggered snow melt and thus erosion. The measured increase in DOC and nitrate concentrations during high flow support these modeling results. Enhanced soil erosion processes on pasture and arable land are expected with increasing heavy rain events and less snow during winter seasons due to climate change. Consequently, SS and organic matter in the river will increase, which will possibly affect brown trout negatively.

show abstract

Sediment transport and siltation of brown trout (Salmo trutta L.) spawning gravels in chalk streams

Cited by 127 publications

References 22 publications

Asynchronicity of fine sediment supply and its effects on transport and storage in a regulated river

Asynchronicity of fine sediment supply and its effects on transport and storage in a regulated river

Climate and land-use changes affecting river sediment and brown trout in alpine countries—a review

Organic matter dynamics and stable isotope signature as tracers of the sources of suspended sediment

Contact Info

Product

Resources

About