High herbivory despite high sediment loads on a fringing coral reef

Coral Reefs ◽  
2022 ◽  
Author(s):  
Albert Pessarrodona ◽  
Sterling B. Tebbett ◽  
Nestor E. Bosch ◽  
David R. Bellwood ◽  
Thomas Wernberg
Keyword(s):  
Coral Reef ◽  
Sediment Loads ◽  
High Sediment

scholarly journals REVIEW OF COASTAL CHARACTERISTICS OF IRON SAND DEPOSITS IN CILACAP CENTRAL JAVA

2016 ◽  
Vol 22 (1) ◽  
pp. 35
Author(s):  
Hananto Kurnio
Keyword(s):  
Key Words ◽  
Sea Level ◽  
Coastal Area ◽  
Depositional Environment ◽  
Sandy Beach ◽  
Beach Ridges ◽  
Central Java ◽  
Sediment Loads ◽  
Sand Deposit ◽  
High Sediment

Mineable iron sand deposits in Cilacap – southern coastal area of Central Java have certain coastal characteristics that need to be studied in order to understand its depositional environment. With the knowledge of such environment, it can be applied to look for other places prospective of iron sand deposits that have the same characteristics especially recently when Cilacap’s deposits were almost depleted. Coastal characteristics of iron sand deposit in Cilacap is shown by successive sandy beach ridges separated by marshy valleys typical of prograded coasts and by dunes of sand elongated parallel to the shore line with elevation varies from 0 m to 15 m above sea level. The iron sand deposit was derived from denudation of andesite and “Old Andesite Formation” enriched in magnetite and ilmenite minerals in the steep elevated and deeply weathered rock hinterlands of Cilacap. High sediment loads of Serayu Basin in the hinterland (3,500-4,500 ton/km2/year; Citarum River basin only 800-1,200 ton/km2/year) was causing extensive deposition of iron sand in the coastal zone. Key words: coast, characteristic, iron sand, Cilacap Endapan pasir besi yang dapat ditambang di Cilacap – pesisir selatan Jawa Tengah memiliki karakteristik pantai tertentu yang perlu dikaji agar dapat dipahami lingkungan pengendapannya. Dengan pengetahuan tentang lingkungan pengendapan tersebut, dapat diterapkan untuk mencari daerah-daerah lain prospek endapan pasir besi yang memiliki karakteristik yang sama terutama pada akhir-akhir ini ketika endapan Cilacap akan habis. Karakteristik pantai endapan pasir besi di Cilacap dicirikan oleh urutan pematang pantai berpasir yang dipisahkan oleh lembah-lembah berawa khas pantai maju dan oleh gumuk-gumuk pasir memanjang sejajar dengan garis pantai dengan ketinggian bervariasi dari 0 m hingga 15 m dari muka laut. Endapan pasir besi di daerah ini berasal dari proses denudasi andesit dan “Formasi Andesit Tua” yang kaya akan mineral magnetit dan ilmenit pada pedalaman Cilacap dengan kondisi elevasi curam dan batuan sangat terlapukkan. Muatan sedimen yang tinggi dari Cekungan Serayu di pedalaman tersebut (3.500-4.500 ton/km2/tahun; cekungan Sungai Citarum hanya 800-1.200 ton/km2/tahun) menyebabkan pengendapan yang sangat luas pasir besi di wilayah pantai. Kata kunci: pantai, karakteristik, pasir besi, Cilacap

scholarly journals Unraveling the structure and composition of Varadero Reef, an improbable and imperiled coral reef in the Colombian Caribbean

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e4119 ◽  
Author(s):  
Valeria Pizarro ◽  
Sara C. Rodríguez ◽  
Mateo López-Victoria ◽  
Fernando A. Zapata ◽  
Sven Zea ◽  
...  
Keyword(s):  
Coral Reef ◽  
Fish Community ◽  
Biological Diversity ◽  
Coral Cover ◽  
Good Condition ◽  
High Species Diversity ◽  
Magdalena River ◽  
High Sediment ◽  
Current Standards

Coral reefs are commonly associated with oligotrophic, well-illuminated waters. In 2013, a healthy coral reef was discovered in one of the least expected places within the Colombian Caribbean: at the entrance of Cartagena Bay, a highly-polluted system that receives industrial and sewage waste, as well as high sediment and freshwater loads from an outlet of the Magdalena River (the longest and most populated river basin in Colombia). Here we provide the first characterization of Varadero Reef’s geomorphology and biological diversity. We also compare these characteristics with those of a nearby reference reef, Barú Reef, located in an area much less influenced by the described polluted system. Below the murky waters, we found high coral cover of 45.1% (±3.9; up to 80% in some sectors), high species diversity, including 42 species of scleractinian coral, 38 of sponge, three of lobster, and eight of sea urchin; a fish community composed of 61 species belonging to 24 families, and the typical zonation of a Caribbean fringing reef. All attributes found correspond to a reef that, according to current standards should be considered in “good condition”. Current plans to dredge part of Varadero threaten the survival of this reef. There is, therefore, an urgent need to describe the location and characteristics of Varadero as a first step towards gaining acknowledgement of its existence and garnering inherent legal and environmental protections.

scholarly journals NEW FURROW FLUME FOR HIGH SEDIMENT LOADS

2005 ◽  
Vol 21 (2) ◽  
pp. 227-236 ◽  
Author(s):  
A. J. Clemmens ◽  
D. L. Bjorneberg
Keyword(s):  
Sediment Loads ◽  
High Sediment

A simple biogeochemical model for estuaries with high sediment loads: Application to the Guadalquivir River (SW Iberia)

2013 ◽  
Vol 265 ◽  
pp. 194-206 ◽  
Author(s):  
J. Ruiz ◽  
D. Macías ◽  
M.A. Losada ◽  
M. Díez-Minguito ◽  
L. Prieto
Keyword(s):  
Biogeochemical Model ◽  
Sediment Loads ◽  
Guadalquivir River ◽  
High Sediment

scholarly journals Flux and fate of river-discharged sediments to the Adriatic Sea

2016 ◽  
Vol 1 (1S) ◽  
Author(s):  
John D. Milliman ◽  
Davide Bonaldo ◽  
Sandro Carniel
Keyword(s):  
Adriatic Sea ◽  
Numerical Models ◽  
Small Rivers ◽  
Geochemical Data ◽  
Seismic Profiling ◽  
Sediment Loads ◽  
Ocean Sediment ◽  
The Impact ◽  
High Sediment ◽  
Small Mountainous Rivers

<p>Small rivers, particularly those draining mountainous terrain, discharge disproportionately large quantities of sediment to the globalocean. Because small mountainous rivers are more susceptible to catastrophic events, they tend to discharge their sediments over relatively short periods of time, such as during floods. The impact of small mountainous rivers is especially evident on the coastal ocean, such as the Adriatic Sea where fully 75% of the estimated 145 million tons (Mt) of discharged sediment comes from rivers with basin areas smaller than 7000 km2. Within this semi-enclosed basin in the northeast of the Mediterranean Sea, of particular note are the high sediment loads of five Albanian rivers (located in the southeast), which, prior to dam construction, collectively discharged about 85 Mt yr<sup>–1</sup> perhaps much of it at hyperpycnal concentrations, which would have allowed the sediment to bypass the shelf and be deposited at greater depths. Geochemical data confirm that Albanian river sediment extends well into the southern and central Adriatic Sea. Delineating and understanding the flux and fate of Adriatic Sea sediments may be best facilitated through the reanalysis of existing river datasets and the acquisition of new river data, particularly during periodic floods, high-resolution seismic profiling coupled with sitespecific coring, as well as application of integrated ocean-sediment numerical models</p>

scholarly journals Unraveling a resilient reef: structure and composition of Varadero, an imperiled coral reef in the Colombian Caribbean

2017 ◽  
Author(s):  
Valeria Pizarro ◽  
Sara C Rodríguez ◽  
Mateo López-Victoria ◽  
Fernando A Zapata ◽  
Sven Zea ◽  
...  
Keyword(s):  
Coral Reef ◽  
Biological Diversity ◽  
Coral Cover ◽  
Good Condition ◽  
Ecosystem Goods And Services ◽  
Goods And Services ◽  
The Caribbean ◽  
Magdalena River ◽  
High Sediment

Coral reefs supply millions of people with ecosystem goods and services, especially those living along tropical coastlines. Unfortunately, these ecosystems are disappearing at an alarming pace. In the Caribbean, the rate of coral loss is high (5.5 – 9.2% per year) and constant. In 2013, a healthy coral reef was discovered in one of the least expected places within the Colombian Caribbean: at the entrance of Cartagena Bay, a highly-polluted system that receives industrial and sewage waste, as well as high sediment and freshwater loads from an outlet of the Magdalena River (the longest and most populated river basin in Colombia). Here we provide the first characterization of Varadero Reef’s geomorphology and biological diversity. We also compare these characteristics with those of a nearby reference reef, Barú Reef, located in an area much less influenced by the described polluted system. Below the murky waters, we found high coral cover of 45.1% (± 3.9; up to 80% in some sectors), three species of lobster, eight of sea urchin, a fish community composed by 61 species from 24 families, and the typical zonation of a Caribbean fringing reef. All attributes found correspond to a reef that, according to current standards should be considered in "good condition". Current plans to dredge part of Varadero threaten the survival of this reef and could hinder efforts to uncover the underpinnings of this reef’s remarkable resilience. There is, therefore, an urgent need to describe the location and characteristics of Varadero as a first step towards gaining acknowledgement of its existence and garnering inherent legal and environmental protections.

Seasonal melting simulation of permafrost rock glaciers and their potential contribution to sediment loads in Alpine catchments

2020 ◽  
Author(s):  
Lucas Reid ◽  
Ulrike Scherer ◽  
Erwin Zehe
Keyword(s):  
Large Scale ◽  
Sediment Load ◽  
Series Data ◽  
Rock Glacier ◽  
Erosion Model ◽  
Permafrost Rock ◽  
Sediment Loads ◽  
Rock Glaciers ◽  
High Sediment ◽  
Seasonal Melting

&lt;p&gt;A common issue with large scale erosion modelling is that local processes are often unaccounted for, either because they haven&amp;#8217;t been included in the model conceptually, or because they are undetected yet. On the other hand, significant deviations from such a general soil erosion model to the measurements can reveal those local processes. We compared the average yearly sediment amounts of a network of turbidity measurement stations in the catchment of the alpine River Inn to the results of the large scale erosion model RUSLE2015 (Panagos et. al.) for long term yearly erosion amounts and found a significant underestimation of sediment loads in three sub catchments. An important source of sediments in alpine rivers comes from glaciers, which explains the high loads in one of the stations, but two of the three high sediment load sub catchments are too low to have substantial valley glaciers. But another potential source of glacial sediment exists in the form of permafrost soils and in this case a specific permafrost form: rock glaciers. Rock glaciers in particular have been spotted in those two high sediment load catchments, but since they are hard to detect from remote sensing due to the surface being covered with rocks, the existence or the exact spatial extent is often unknown. But with rising temperatures in the Alps, the areas in which permafrost rock glaciers can exist decreases every year and the depth of the seasonal melting layer increases.&lt;/p&gt;&lt;p&gt;We propose the hypothesis that the high sediment loads in those sub catchments are caused by increasingly deeper melting of permafrost rock glaciers. This process releases fine materials which have been trapped frozen since the glacial period and are now being eroded and transported to the alpine streams. To get an estimation of potential erodible material from rock glacier melting in the respective sub catchments, we developed a model to simulate the heat diffusion from the air into the frozen ground, while accommodating for the change in specific thermal capacity. The model (developed in Python) takes air temperature time series data as input and can be configured for varying ground stratification setups with different thermal diffusivity values depending on the ground properties.&lt;/p&gt;&lt;p&gt;From the simulated melting depth of an average square meter of rock glacier we extrapolate the mass of melted material to the potential permafrost erosion material available in the River Inn sub catchments. We show that this source of sediments can be significant and needs to be factored in should an erosion model be used to calculate sediment input into the rivers. But, with the estimation of sediment load from permafrost origins narrowed down, improving a large-scale erosion model like the RUSLE2015 for this alpine mountain region by accounting for local processes like this one is possible.&amp;#160;&lt;/p&gt;

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