Diadromous fish modified timing of upstream migration over the last 30 years in France

2020 ◽  
Author(s):  
Marion Legrand ◽  
Cédric Briand ◽  
Laëtitia Buisson ◽  
Timothée Besse ◽  
Gwenaël Artur ◽  
...  
Keyword(s):  
Upstream Migration ◽  
Diadromous Fish

scholarly journals Geomorphic effects of recurrent outburst superfloods in the Yigong River on the southeastern margin of Tibet

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kaiheng Hu ◽  
Chaohua Wu ◽  
Li Wei ◽  
Xiaopeng Zhang ◽  
Qiyuan Zhang ◽  
...  
Keyword(s):  
Landslide Dam ◽  
Upstream Migration ◽  
One Dimensional ◽  
Landform Evolution ◽  
Outburst Floods ◽  
Stepwise Method ◽  
Large Landslide ◽  
Southeastern Margin ◽  
Channel Slope ◽  
The One

AbstractLandslide dam outburst floods have a significant impact on landform evolution in high mountainous areas. Historic landslide dams on the Yigong River, southeastern Tibet, generated two outburst superfloods > 105 m3/s in 1902 and 2000 AD. One of the slackwater deposits, which was newly found immediately downstream of the historic dams, has been dated to 7 ka BP. The one-dimensional backwater stepwise method gives an estimate of 225,000 m3/s for the peak flow related to the paleo-stage indicator of 7 ka BP. The recurrence of at least three large landslide dam impoundments and super-outburst floods at the exit of Yigong Lake during the Holocene greatly changed the morphology of the Yigong River. More than 0.26 billion m3 of sediment has been aggraded in the dammed lake while the landslide sediment doubles the channel slope behind the dam. Repeated landslide damming may be a persistent source of outburst floods and impede the upstream migration of river knickpoints in the southeastern margin of Tibet.

Toward a roadmap for diadromous fish conservation: the Big Five considerations

2021 ◽  
Author(s):  
Pieterjan Verhelst ◽  
Jan Reubens ◽  
David Buysse ◽  
Peter Goethals ◽  
Jeroen Van Wichelen ◽  
...  
Keyword(s):  
Big Five ◽  
Fish Conservation ◽  
Diadromous Fish

Stretched to the limit; can a short pelagic larval duration connect adult populations of an Indo-Pacific diadromous fish (Kuhlia rupestris)?

2013 ◽  
Vol 22 (6) ◽  
pp. 1518-1530 ◽  
Author(s):  
P. Feutry ◽  
A. Vergnes ◽  
D. Broderick ◽  
J. Lambourdière ◽  
P. Keith ◽  
...  
Keyword(s):  
Pelagic Larval Duration ◽  
Larval Duration ◽  
Diadromous Fish

scholarly journals Assessing demographic effects of dams on diadromous fish: a case study for Atlantic salmon in the Penobscot River, Maine

2015 ◽  
Vol 72 (8) ◽  
pp. 2423-2437 ◽  
Author(s):  
Julie L. Nieland ◽  
Timothy F. Sheehan ◽  
Rory Saunders
Keyword(s):  
Atlantic Salmon ◽  
Performance Metrics ◽  
Survival Rates ◽  
Population Viability Analysis ◽  
River System ◽  
Diadromous Fish ◽  
Viability Analysis ◽  
Penobscot River ◽  
Passage Efficiency ◽  
Demographic Effects

Abstract Dams are a major contributor to the historic decline and current low abundance of diadromous fish. We developed a population viability analysis to assess demographic effects of dams on diadromous fish within a river system and demonstrated an application of the model with Atlantic salmon in the Penobscot River, Maine. We used abundance and distribution of wild- and hatchery-origin adult salmon throughout the watershed as performance metrics. Salmon abundance, distribution to upper reaches of the Penobscot watershed, and the number and proportion of wild-origin fish in the upper reaches of the Penobscot watershed increased when dams, particularly mainstem dams, were removed or passage efficiency was increased. Salmon abundance decreased as indirect latent mortality per dam was increased. Salmon abundance increased as marine or freshwater survival rates were increased, but the increase in abundance was larger when marine survival was increased than when freshwater survival was increased. Without hatchery supplementation, salmon abundance equalled zero with low marine and freshwater survival but increased when marine and freshwater survival rates were increased. Models, such as this one, that incorporate biological, environmental, and functional parameters can be used to predict ecological responses of fish populations and can help evaluate and prioritize management and restoration actions for diadromous fish.

scholarly journals Culverts in paved roads as suitable passages for Neotropical fish species

2012 ◽  
Vol 10 (4) ◽  
pp. 763-770 ◽  
Author(s):  
Sergio Makrakis ◽  
Theodore Castro-Santos ◽  
Maristela Cavicchioli Makrakis ◽  
Ricardo Luiz Wagner ◽  
Maurício Spagnolo Adames
Keyword(s):  
Fish Passage ◽  
Fish Movement ◽  
Upstream Migration ◽  
Migratory Species ◽  
Neotropical Fish ◽  
Potential Barriers ◽  
Medium Risk ◽  
Fall Height ◽  
Additional Monitoring ◽  
Spawning Success

Improperly installed or poorly maintained culverts can pose a serious threat to fish by disrupting their habitat and endangering spawning success. Road culverts that are not designed for fish passage frequently can become obstacles. This can be especially problematic for migratory species, but can lead to fragmentation of resident populations as well. This study evaluated 40 culverts of 29 sites within a 25-km radius from Toledo city, Paraná State, southern Brazil, with respect to their likely effects on movement of the local ichthyofauna. We collected data on the shape and length of culverts, culvert material, waterfall height, water column depth, slope, and estimated flow velocity. Culverts were categorized by level of barrier risk for upstream migration: high, medium, low, and impassable, as well as the type of barrier posed (fall height, depth, length and velocity). Most of culverts analyzed were considered potential barriers to fish movement, with 45% classified as impassible, 45% as high risk, 10% as medium risk, and no culverts as low risk. Brazilian culverts as fishways will require additional monitoring and studies to corroborate the premises proposed in the present study. Road culvert projects that are properly built and maintained will be able to simultaneously improve function of roadways and protect fish populations.

scholarly journals Macro-roughness model of bedrock–alluvial river morphodynamics

2015 ◽  
Vol 3 (1) ◽  
pp. 113-138 ◽  
Author(s):  
L. Zhang ◽  
G. Parker ◽  
C. P. Stark ◽  
T. Inoue ◽  
E. Viparelli ◽  
...  
Keyword(s):  
Fixed Bed ◽  
River Mouth ◽  
Steady State Solution ◽  
Bedload Transport ◽  
Spatiotemporal Variation ◽  
Sediment Supply ◽  
Complex Case ◽  
Upstream Migration ◽  
Major Advance ◽  
Bedrock Erosion

Abstract. The 1-D saltation–abrasion model of channel bedrock incision of Sklar and Dietrich (2004), in which the erosion rate is buffered by the surface area fraction of bedrock covered by alluvium, was a major advance over models that treat river erosion as a function of bed slope and drainage area. Their model is, however, limited because it calculates bed cover in terms of bedload sediment supply rather than local bedload transport. It implicitly assumes that as sediment supply from upstream changes, the transport rate adjusts instantaneously everywhere downstream to match. This assumption is not valid in general, and thus can give rise to unphysical consequences. Here we present a unified morphodynamic formulation of both channel incision and alluviation that specifically tracks the spatiotemporal variation in both bedload transport and alluvial thickness. It does so by relating the bedrock cover fraction to the ratio of alluvium thickness to bedrock macro-roughness, rather than to the ratio of bedload supply rate to capacity bedload transport. The new formulation (MRSAA) predicts waves of alluviation and rarification, in addition to bedrock erosion. Embedded in it are three physical processes: alluvial diffusion, fast downstream advection of alluvial disturbances, and slow upstream migration of incisional disturbances. Solutions of this formulation over a fixed bed are used to demonstrate the stripping of an initial alluvial cover, the emplacement of alluvial cover over an initially bare bed and the advection–diffusion of a sediment pulse over an alluvial bed. A solution for alluvial–incisional interaction in a channel with a basement undergoing net rock uplift shows how an impulsive increase in sediment supply can quickly and completely bury the bedrock under thick alluvium, thus blocking bedrock erosion. As the river responds to rock uplift or base level fall, the transition point separating an alluvial reach upstream from an alluvial–bedrock reach downstream migrates upstream in the form of a "hidden knickpoint". A tectonically more complex case of rock uplift subject to a localized zone of subsidence (graben) yields a steady-state solution that is not attainable with the original saltation–abrasion model. A solution for the case of bedrock–alluvial coevolution upstream of an alluviated river mouth illustrates how the bedrock surface can be progressively buried not far below the alluvium. Because the model tracks the spatiotemporal variation in both bedload transport and alluvial thickness, it is applicable to the study of the incisional response of a river subject to temporally varying sediment supply. It thus has the potential to capture the response of an alluvial–bedrock river to massive impulsive sediment inputs associated with landslides or debris flows.

scholarly journals Turbidity in the fluvial Gironde Estuary (southwest France) based on 10-year continuous monitoring: sensitivity to hydrological conditions

2015 ◽  
Vol 19 (6) ◽  
pp. 2805-2819 ◽  
Author(s):  
I. Jalón-Rojas ◽  
S. Schmidt ◽  
A. Sottolichio
Keyword(s):  
River Flow ◽  
Hysteresis Loops ◽  
Annual Runoff ◽  
Transitional Period ◽  
Estuarine System ◽  
Upstream Migration ◽  
Hydrological Conditions ◽  
Frequency Monitoring ◽  
Turbidity Level ◽  
River Floods

Abstract. Climate change and human activities impact the volume and timing of freshwater input to estuaries. These modifications in fluvial discharges are expected to influence estuarine suspended sediment dynamics, and in particular the turbidity maximum zone (TMZ). Located in southwest France, the Gironde fluvial-estuarine system has an ideal context to address this issue. It is characterized by a very pronounced TMZ, a decrease in mean annual runoff in the last decade, and it is quite unique in having a long-term and high-frequency monitoring of turbidity. The effect of tide and river flow on turbidity in the fluvial estuary is detailed, focusing on dynamics related to changes in hydrological conditions (river floods, periods of low discharge, interannual changes). Turbidity shows hysteresis loops at different timescales: during river floods and over the transitional period between the installation and expulsion of the TMZ. These hysteresis patterns, that reveal the origin of sediment, locally resuspended or transported from the watershed, may be a tool to evaluate the presence of remained mud. Statistics on turbidity data bound the range of river flow that promotes the upstream migration of TMZ in the fluvial stations. Whereas the duration of the low discharge period mainly determines the TMZ persistence, the freshwater volume during high discharge periods explains the TMZ concentration at the following dry period. The evolution of these two hydrological indicators of TMZ persistence and turbidity level since 1960 confirms the effect of discharge decrease on the intensification of the TMZ in tidal rivers; both provide a tool to evaluate future scenarios.

scholarly journals [First occurrence of Sea Lamprey, Petromyzon marinus Linnaeus 1758 (Agnatha, Petromyzontiformes, Petromyzontidae) in the River Mignone (Northern Lazio).]

2021 ◽  
Vol 8 (1) ◽  
pp. 29-34
Author(s):  
Vincenzo Ferri ◽  
Paolo Crescia ◽  
Christiana Soccini ◽  
Alessio Olini ◽  
Stefano Celletti
Keyword(s):  
Endangered Species ◽  
Petromyzon Marinus ◽  
Sea Lamprey ◽  
Environmental Context ◽  
Upstream Migration ◽  
Rare And Endangered Species ◽  
Fish Ladder ◽  
First Occurrence ◽  
Rare And Endangered

[The spring presence of two individuals of the Sea lamprey, Petromyzon marinus, in the River Mignone near Tarquinia (Northern Lazio) could highlight a new Italian reproductive site of this rare and endangered species. This exceptional possibility could certainly be favored by the good quality of both the waters of the Mignone, and the environmental context of the record, but would require the urgent equipment of the barrier of Le Mole with a fish ladder in order to allow the sea lamprey’s upstream migration towards the areas of the upper course, even more suitable for their reproduction].   [Article in Italian]

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