Occurrence of the Cutfin Poacher, Xeneretmus leiops, on the Continental Shelf off the Columbia River Mouth

Copeia ◽  
1973 ◽  
Vol 1973 (4) ◽  
pp. 814
Author(s):  
Thomas C. Ginn ◽  
Carl E. Bond
Keyword(s):  
Continental Shelf ◽  
River Mouth ◽  
Columbia River

Mapping Physical Characteristics of the Columbia River Mouth Using Transmittered Diving Waterbirds

2013 ◽  
Author(s):  
Daniel D. Roby ◽  
Donald E. Lyons ◽  
Adam Peck-Richardson ◽  
James A. Lerczak
Keyword(s):  
River Mouth ◽  
Columbia River ◽  
Physical Characteristics

Field and Numerical Study of the Columbia River Mouth

2013 ◽  
Author(s):  
Guy Gelfenbaum ◽  
Jamie MacMahan ◽  
Ad Reniers
Keyword(s):  
Numerical Study ◽  
River Mouth ◽  
Columbia River

scholarly journals Modeling biogeochemical processes in sediments from the Rhône River prodelta area (NW Mediterranean Sea)

2011 ◽  
Vol 8 (1) ◽  
pp. 549-592 ◽  
Author(s):  
L. Pastor ◽  
C. Cathalot ◽  
B. Deflandre ◽  
E. Viollier ◽  
K. Soetaert ◽  
...  
Keyword(s):  
Organic Matter ◽  
Oxygen Consumption ◽  
Continental Shelf ◽  
Carbon Mineralization ◽  
River Mouth ◽  
Total Carbon ◽  
Large Contribution ◽  
Organic Carbon Content ◽  
Rhône River ◽  
Rhone River

Abstract. In-situ oxygen microprofiles, sediment organic carbon content and pore-water concentrations of nitrate, ammonium, iron, manganese and sulfides obtained in sediments from the Rhône River prodelta and its adjacent continental shelf were used to constrain a numerical diagenetic model. Results showed that (1) organic matter from the Rhône River is composed of a fraction of fresh material associated to high first-order degradation rate constants (11–33 yr−1), (2) burial efficiency (burial/input ratio) in the Rhône prodelta (within 3 km of the river outlet) can be up to 80%, and decreases to ~20% on the adjacent continental shelf 10–15 km further offshore (3) there is a large contribution of anoxic processes to total mineralization in sediments near the river mouth, certainly due to large inputs of fresh organic material combined with high sedimentation rates, (4) diagenetic by-products originally produced during anoxic organic matter mineralization are almost entirely precipitated (>97%) and buried in the sediment, which leads to (5) a low contribution of the re-oxidation of reduced products to total oxygen consumption. Consequently, total carbon mineralization rates as based on oxygen consumption rates and using Redfield stoichiometry can be largely underestimated in such River Ocean dominated Margins (RiOMar) environments.

scholarly journals Temporal variability of carbon recycling in coastal sediments influenced by rivers: assessing the impact of flood inputs in the Rhône River prodelta

2010 ◽  
Vol 7 (3) ◽  
pp. 1187-1205 ◽  
Author(s):  
C. Cathalot ◽  
C. Rabouille ◽  
L. Pastor ◽  
B. Deflandre ◽  
E. Viollier ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Continental Shelf ◽  
Spatial Pattern ◽  
River Mouth ◽  
Ex Situ ◽  
Rhône River ◽  
Reactive Material ◽  
Degradation Rates ◽  
Rhone River ◽  
The Impact

Abstract. River deltas are particularly important in the marine carbon cycle as they represent the transition between terrestrial and marine carbon: linked to major burial zones, they are reprocessing zones where large carbon fluxes can be mineralized. In order to estimate this mineralization, sediment oxygen uptake rates were measured in continental shelf sediments and river prodelta over different seasons near the outlet of the Rhône River in the Mediterranean Sea. On a selected set of 10 stations in the river prodelta and nearby continental shelf, in situ diffusive oxygen uptake (DOU) and laboratory total oxygen uptake (TOU) measurements were performed in early spring and summer 2007 and late spring and winter 2008. In and ex situ DOU did not show any significant differences except for shallowest organic rich stations. Sediment DOU rates show highest values concentrated close to the river mouth (approx. 20 mmol O2 m−2 d−1) and decrease offshore to values around 4.5 mmol O2 m−2 d−1 with lowest gradients in a south west direction linked to the preferential transport of the finest riverine material. Core incubation TOU showed the same spatial pattern with an averaged TOU/DOU ratio of 1.2±0.4. Temporal variations of sediment DOU over different sampling periods, spring summer and late fall, were limited and benthic mineralization rates presented a stable spatial pattern. A flood of the Rhône River occurred in June 2008 and delivered up to 30 cm of new soft muddy deposit. Immediately after this flood, sediment DOU rates close to the river mouth dropped from around 15–20 mmol O2 m−2 d−1 to values close to 10 mmol O2 m−2 d−1, in response to the deposition near the river outlet of low reactivity organic matter associated to fine material. Six months later, the oxygen distribution had relaxed back to its initial stage: the initial spatial distribution was found again underlining the active microbial degradation rates involved and the role of further deposits. These results highlight the immediate response of the sediment oxygen system to flood deposit and the rapid relaxation of this system towards its initial state (6 months or less) potentially linked to further deposits of reactive material.

scholarly journals FORECASTING THE WAVE-CURRENT INTERACTIONS AT THE MOUTH OF THE COLUMBIA RIVER, OR, USA

2012 ◽  
Vol 1 (33) ◽  
pp. 53 ◽  
Author(s):  
Sarah Kassem ◽  
H. Tuba Ozkan-Haller
Keyword(s):  
Pacific Northwest ◽  
Mean Squared Error ◽  
River Mouth ◽  
Columbia River ◽  
Tidal Currents ◽  
General Effect ◽  
The Pacific ◽  
Wave Forecast ◽  
Channel Wave ◽  
Wave Heights

An operational wave forecast of the area near the mouth of the Columbia River is presented. This region is known for its large waves and strong tidal currents. The forecast is forced with full directional spectra obtained from a refined WaveWatchIII forecast of the Pacific Northwest, and tidal current inputs are obtained from an estuarine circulation forecast of the Columbia River. The forecast has been operational since August 2011 providing short-term predictive wave information at the mouth of the Columbia River. Results from a 6-month period are promising, with a normalized root-mean-squared error (NRMSE) of 16% at the location of an inshore buoy, which is located outside the zone of tidal influence in 25 m water depth. Near the river mouth and in the channel, wave heights are heavily dominated by the tidal currents which significantly increase wave heights on ebb tides. Hindcast results shows that the model is able to predict the general effect of the tidal currents with a NRMSE of 30% in wave heights at the river mouth. Despite some of the model limitations, it still provides valuable information to navigators and bar pilots since it includes the effects of the tidal currents.

Water column and bottom gradients on the continental shelf eastward of the Amazon River mouth and implications for mesophotic reef occurrence

2022 ◽  
Vol 225 ◽  
pp. 103642
Author(s):  
Nils E. Asp ◽  
José Diego Gomes ◽  
Vando J.C. Gomes ◽  
Claudia Y. Omachi ◽  
Ariane M.M. Silva ◽  
...  
Keyword(s):  
Continental Shelf ◽  
Water Column ◽  
River Mouth ◽  
Amazon River ◽  
Mesophotic Reef

scholarly journals Modeling biogeochemical processes in sediments from the Rhône River prodelta area (NW Mediterranean Sea)

2011 ◽  
Vol 8 (5) ◽  
pp. 1351-1366 ◽  
Author(s):  
L. Pastor ◽  
C. Cathalot ◽  
B. Deflandre ◽  
E. Viollier ◽  
K. Soetaert ◽  
...  
Keyword(s):  
Organic Matter ◽  
Oxygen Consumption ◽  
Continental Shelf ◽  
Carbon Mineralization ◽  
River Mouth ◽  
Total Carbon ◽  
Large Contribution ◽  
Organic Carbon Content ◽  
Rhône River ◽  
Rhone River

Abstract. In situ oxygen microprofiles, sediment organic carbon content, and pore-water concentrations of nitrate, ammonium, iron, manganese, and sulfides obtained in sediments from the Rhône River prodelta and its adjacent continental shelf were used to constrain a numerical diagenetic model. Results showed that (1) the organic matter from the Rhône River is composed of a fraction of fresh material associated to high first-order degradation rate constants (11–33 yr−1); (2) the burial efficiency (burial/input ratio) in the Rhône prodelta (within 3 km of the river outlet) can be up to 80 %, and decreases to ~20 % on the adjacent continental shelf 10–15 km further offshore; (3) there is a large contribution of anoxic processes to total mineralization in sediments near the river mouth, certainly due to large inputs of fresh organic material combined with high sedimentation rates; (4) diagenetic by-products originally produced during anoxic organic matter mineralization are almost entirely precipitated (>97 %) and buried in the sediment, which leads to (5) a low contribution of the re-oxidation of reduced products to total oxygen consumption. Consequently, total carbon mineralization rates as based on oxygen consumption rates and using Redfield stoichiometry can be largely underestimated in such River-dominated Ocean Margins (RiOMar) environments.

Bathymetric Distribution of Brittlestars (Ophiuroidea) Collected off the Northern Oregon Coast

1965 ◽  
Vol 22 (6) ◽  
pp. 1407-1424 ◽  
Author(s):  
Sergei Astrahantseff ◽  
Miles S. Alton
Keyword(s):  
Atomic Energy Commission ◽  
River Mouth ◽  
Benthic Fauna ◽  
Columbia River ◽  
Single Species ◽  
Species Number ◽  
Bathymetric Distribution ◽  
Number Of Species ◽  
Study Species ◽  
Benthic Zone

A cooperative study by the Bureau of Commercial Fisheries and the U. S. Atomic Energy Commission was undertaken to evaluate the composition of benthic fauna indigenous to waters adjacent to the Columbia River mouth. Standard stations were established by 25-fath intervals between 50 and 500 fath, and by 50-fath intervals from 500 to 1050 fath. Fifty- to 500-fath stations were monitored seasonally while sampling of deeper stations was generally restricted to spring and summer cruises.Twenty-four species of ophiuroids representing eight families and 14 genera were collected during this study. Species number varied by station ranging from one at 650 fath to a maximum of nine species at 300 fath.The number of species of ophiuroids by benthic zone showed a general increase with increasing depth. The total number of species collected by benthic zone was 4 from the sublittoral, 8 from the upper bathyal, 13 from the lower bathyal, and 15 from the abyssal. One, three, and eight species were confined to the outer sublittoral, lower bathyal, and abyssal, respectively.The highest availability of ophiuroids occurred between 150 and 250 fath and between 800 and 1050 fath. Lowest availability occurred at 125, 325, and 350 fath where few or no ophiuroids were observed. Larger catches of ophiuroids were estimated to contain from 500 to 2000 individuals. A single species, Ophiura sarsii, consistently dominated catches from 150 to 250 fath; while four species, Ophiocten pacificum, Ophiolimna bairdi, Ophiomusium lymani, and Ophiophthalmus normani, dominated catches between 800 and 1050 fath.The families Ophiuridae and Ophiacanthidae predominate in the study area. Together, they account for the majority of species collected which include the five most abundant species.The bathymetric distribution of ophiuroids from the Columbia River trackline illustrates a changing species composition with increasing depth, with the existence of both stenobathic and eurybathic species.

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