scholarly journals Ecology of gassy, organic-rich sediment in a shallow subtidal area on the Kattegat coast of Denmark

1993 ◽  
Vol 100 ◽  
pp. 265-271 ◽  
Author(s):  
PR Dando ◽  
T Fenchel ◽  
P Jensen ◽  
SCM O'Hara ◽  
SJ Niven ◽  
...  
Keyword(s):  
Subtidal Area ◽  
Shallow Subtidal ◽  
Organic Rich Sediment

A prickly subject: innovative handling of a difficult prey

2018 ◽  
Vol 40 (2) ◽  
pp. 294
Author(s):  
Linda Behrendorff
Keyword(s):  
Canis Lupus ◽  
Eastern Coast ◽  
Island Ecosystems ◽  
Subtidal Area ◽  
Shallow Subtidal ◽  
Handling Technique ◽  
Prey Handling ◽  
Ambush Predators ◽  
Tachyglossus Aculeatus

Canids are generally considered to be ambush predators, but in island ecosystems adaptability and flexibility are essential for survival. Dingoes (Canis lupus dingo) attack and kill their prey in a variety of ways including utilising waterbodies. Here I document the drowning of an adult short-beaked echidna (Tachyglossus aculeatus) before consumption by a dingo using the coastal surf beach intertidal to shallow subtidal area on the eastern coast of Fraser Island (K’gari), highlighting an innovative prey-handling technique.

Environmental controls on the distribution of Atrypoidea species in Upper Silurian strata of arctic Canada

1984 ◽  
Vol 21 (2) ◽  
pp. 131-144 ◽  
Author(s):  
Brian Jones ◽  
G. M. Narbonne
Keyword(s):  
Environmental Factors ◽  
Environmental Parameters ◽  
Arctic Canada ◽  
Subtidal Area ◽  
Environmental Controls ◽  
Subtidal Environment ◽  
Close Proximity ◽  
Utmost Care ◽  
Shallow Subtidal ◽  
Upper Silurian

Evidence from numerous localities throughout the Upper Silurian strata of arctic Canada suggests that the ranges of the various species of Atrypoidea were controlled primarily by environmental factors. Atrypoidea bioherma n. sp. occurred only on and immediately around bioherms. Atrypoidea foxi inhabited subtidal areas in an offshore position, and especially those areas between the bioherms with which A. bioherma were associated. Atrypoidea phoca apparently lived in a shallow subtidal area in close proximity to the shoreline. Atrypoidea erebus inhabited environments ranging from the low intertidal to shallow subtidal. Atrypoidea netserki lived in a shallow subtidal environment close to shore.Fluctuations in bathymetry and other environmental parameters during the deposition of the Upper Silurian strata resulted in an apparent zonation of Atrypoidea species. These zones, however, are ecologically controlled and can therefore only be utilized for biostratigraphic purposes with the utmost care.

Recent changes in shallow subtidal fauna with new invertebrate records in Europe's first marine reserve, Lough Hyne

2018 ◽  
Vol 118B (1) ◽  
pp. 29
Author(s):  
Cynthia D. Trowbridge ◽  
Colin Little ◽  
Caitlin Q. Plowman ◽  
Lukas S. Ferrenburg ◽  
Hayley M. Resk ◽  
...  
Keyword(s):  
Marine Reserve ◽  
Shallow Subtidal ◽  
Lough Hyne

The chemostratigraphy and environmental significance of the Marlstone and Junction Bed (Beacon Limestone, Toarcian, Lower Jurassic, Dorset, UK)

2021 ◽  
pp. 1-15
Author(s):  
Hugh C. Jenkyns ◽  
Sophie Macfarlane
Keyword(s):  
Carbon Isotope ◽  
Oxygen Isotopes ◽  
Lower Jurassic ◽  
Carbon And Oxygen Isotopes ◽  
Oceanic Anoxic Event ◽  
Nodular Limestone ◽  
Anoxic Event ◽  
Reference Curves ◽  
High Degree ◽  
Organic Rich Sediment

Abstract Two fallen blocks of the Marlstone and stratigraphically overlying Junction Bed sampled on the beach below Doghouse Cliff in Dorset, UK (Wessex Basin) have been examined for carbon and oxygen isotopes of bulk carbonate as well as for strontium, carbon and oxygen isotopes and Mg:Ca ratios in the contained belemnites. The sequence, which contains most of the Toarcian zones and subzones within a metre or less of grey to yellow to pink, red and brown fossil-rich nodular limestone, is extremely condensed and lithologically similar to pelagic red limestones of the Tethyan Jurassic that are locally mineralized with Fe-Mn oxyhydroxides (e.g., Rosso Ammonitico). Strontium-isotope ratios of the contained belemnites are compatible with existing reference curves and both blocks show a rise to more radiogenic values post-dating the Pliensbachian–Toarcian boundary. The high degree of correlation between the relatively negative carbon and oxygen isotopes of the bulk carbonate is compatible with significant diagenetic overprint, and contrasts with higher carbon-isotope values in coeval condensed coccolith-rich limestones elsewhere. Evidence for the characteristic signature of the Toarcian Oceanic Anoxic Event, as represented by organic-rich sediment, is absent, possibly owing to a stratigraphic gap. Both blocks exhibit abrupt carbon-isotope shifts to lower values, one of which could represent the limbs of an incompletely recorded negative excursion associated with the Toarcian Oceanic Anoxic Event. That the Toarcian Oceanic Anoxic Event was also a significant hyperthermal is illustrated in both blocks by a drop in oxygen-isotope values and rise in Mg:Ca ratios of belemnites close to the base of the Junction Bed in the lowest part of the serpentinum zone.

scholarly journals Bivalves and Gastropods of the Gulf of Tehuantepec, Mexico: A Checklist of Species with Notes on Their Habitat and Local Distribution

2009 ◽  
Vol 2009 ◽  
pp. 1-12 ◽  
Author(s):  
Eduardo Ríos-Jara ◽  
Ceciel-M. Navarro-Caravantes ◽  
Cristian-M. Galván-Villa ◽  
Ernesto Lopez-Uriarte
Keyword(s):  
Continental Shelf ◽  
Coastal Lagoons ◽  
Taxonomic Composition ◽  
Total Count ◽  
Bivalve Species ◽  
Local Distribution ◽  
Gastropod Species ◽  
Gulf Of Tehuantepec ◽  
Shallow Subtidal

The taxonomic composition of 160 species of bivalves and gastropods recorded in the Gulf of Tehuantepec is presented with information on their habitat and distribution along 10 different localities of the shoreline and 42 stations of the continental shelf. The species were on sandy and rocky beaches, coastal lagoons, estuaries, mangroves, rocky breakwaters of ports, and shallow subtidal areas (14–47 m depth). A total of 78 bivalve species and 82 gastropod species were recorded. Most of these were associated with sandy and rocky beaches and breakwaters of ports. The estuaries host 30 species and the coastal lagoons only two. In the shallow subtidal there were 18 gastropod species and 40 bivalve species representing 36.3% of all. This study adds 24 bivalve species and 29 gastropod species not recorded in previous studies for a total count of 213 species (102 bivalves and 111 gastropods) for Gulf of Tehuantepec.

scholarly journals Color in ostracode shells: taphonomy and paleotemperature interpretation

1992 ◽  
Vol 6 ◽  
pp. 172-172
Author(s):  
Mervin Kontrovitz ◽  
Jerry Marie Slack ◽  
Nigel R. Ainsworth ◽  
Richard D. Burnett
Keyword(s):  
Elevated Temperatures ◽  
Geologic History ◽  
Pale Yellow ◽  
Color Changes ◽  
Igneous Intrusions ◽  
Wide Range ◽  
Color Differences ◽  
Dark Color ◽  
Coloring Agents ◽  
Organic Rich Sediment

Interpretations of geologic history would be enhanced if taphonomic processes, including color changes in shells, were better known. This study deals with the origins and alteration of post-mortem colors in podocopid ostracodes. Modern shells were subjected to elevated temperatures and pressures in reactor vessels with sediments, simulating some burial conditions. Fossil shells from outcrops and boreholes were heated and treated with solvents, in an attempt to identify the coloring agent(s).Modern marine shells are white to pale yellow (Munsell 5Y 8/1 – 2.5Y 8/4). Upon heating at atmosphere, up to about 650°, they became slightly redder, slightly darker, and less color saturated, but never dark (Munsell “value” less than 5). From 650-850° they became yellower and lighter, and above 850° chalky and more yellow. Shells at elevated temperatures and pressures (T-P) with organic-poor sediments and/or iron compounds developed higher color values and lower chromas; they did not become dark. Thus, modern ostracode shells subjected to elevated T-P changed colors, but alone never attained the dark colors seen in many fossils. Only those heated in matured organic-rich sediment and/or crude oils became dark (dark grays, browns, and blacks), like some fossils. Fossil ostracodes from boreholes in Mesozoic and Cenozoic sedimentary rocks showed downhole color differences similar to those from experiments. That is, the colors of fossils are different in hue, value and chroma in different thermal zones and ostracode color appears to be broadly indicative of thermal history.Fossils near igneous intrusions are dark, while the lowered values and chromas of those in metamorphics also are correlatable with paleotemperatures. Reheated dark fossils lightened at about 375-450°, eventually becoming pale yellow to white, apparently indicating that organic coloring agents were driven off. This, and the fact that modern ostracodes develop dark colors only when heated in organic-rich substances, support the contention that the dark color originates from extrinsic organic materials. Pyritized shells become weak red (Munsell 10R 4/4) upon heating; thus, they can be distinguised from those colored by organics.Therefore, ostracode colors appear to be diagnostic of T-P and present the potential for use in paleotemperature reconstructions. A wide range of fossils, including conodonts, phosphatic brachiopods, scolecodonts, and palynomorphs are known to show recognizable and useful evidence of thermal maturation and it is proposed that ostracodes be added to the list.

scholarly journals The Effects of the Invasive Seaweed Asparagopsis Armata on Native Rock Pool Communities: Evidences from Experimental Exclusion

2020 ◽  
Author(s):  
Carla Silva ◽  
Marco Lemos ◽  
Rui Gaspar ◽  
Carlos Gonçalves ◽  
João Neto
Keyword(s):  
Algal Species ◽  
Taxonomic Composition ◽  
Habitat Destruction ◽  
Rock Pools ◽  
Red Macroalgae ◽  
Invasive Seaweed ◽  
Shallow Subtidal ◽  
Intertidal Seaweed ◽  
Macroalgal Assemblage ◽  
Asparagopsis Armata

Biological invasions represent a threat to ecosystems, through competition and habitat destruction, which may result in significant changes of the invaded community. Asparagopsis armata is a red macroalgae (Rodophyta) globally recognized as an invasive species. It is found from the intertidal to shallow subtidal areas, on rock or epiphytic, forming natural vegetation belts on exposed coasts. This study evaluated the variations on native intertidal seaweed and macroinvertebrate assemblages inhabiting rock pools with and without the presence of the invasive macroalgae A. armata. To achieve this, manipulation experiments on Atlantic (Portugal) rock pools were done. Three rock pools were maintained without A. armata by manual removal of macroalgae, and three others were not experimentally manipulated during the study period and A. armata was freely present. In this study the variations between different rock pools were assessed. Results showed different patterns in the macroalgae composition of assemblages but not for the macrobenthic communities. Ellisolandia elongata was the main algal species affected by the invasion of A. armata. Invaded pools tended to show less species richness, showing a more constant and conservative structure, with lower variation of its taxonomic composition than the pools not containing A. armata, where the variability between samples was always higher. Despite the importance of the achieved results, further data based on observation of long-term series are needed, in order to further understand more severe effects of the invader A. armata on native macroalgal assemblage.

scholarly journals CARACTERÍSTICAS OCEANOGRÁFICAS EN LA ISLA MALPELO Y SU RELACIÓN CON LA CUENCA OCEÁNICA DEL PACÍFICO COLOMBIANO

2016 ◽  
Vol 40 ◽  
Author(s):  
Efraín Rodríguez Rubio ◽  
Alan Giraldo
Keyword(s):  
Water Mass ◽  
Terrestrial Ecosystems ◽  
In Situ Data ◽  
Pelagic Environment ◽  
Shallow Subtidal ◽  
Oceanographic Data ◽  
Malpelo Island ◽  
Physical And Chemical ◽  
Colombian Pacific

Malpelo Island forms the insular ecoregion of the Colombian Pacific, and is composed by a mosaic of terrestrial ecosystems, and unique coastal and shallow subtidal systems. Considering its insular nature, the oceanographic features of this locality are expected to be related with the physical and chemical dynamics of the Eastern Tropical Pacific (ETP) and be modulated by the regional dynamic of the Colombian Pacific Oceanic Basin (COPC in Spanish). In this work, in situ data was used to describe the thermohaline conditions in the water column in Malpelo Island and identify key water mass during the two contrasting hydro-meteorological periods of the COPC. Furthermore, we analyzed the thermal and haline variability in the COPC and defined the surface geostrophic flow from in situ oceanographic data during the same time in order to evaluate its effect on the oceanographic conditions in the pelagic environment off Malpelo Island.

scholarly journals Famennian carbonate microfacies from the Preslavtsi-2 well (Moesian Platform, north-eastern Bulgaria)

2019 ◽  
Vol 48 (2) ◽  
pp. 13-24
Author(s):  
Polina Andreeva
Keyword(s):  
Marine Environments ◽  
Fair Weather ◽  
Carbonate Microfacies ◽  
North Eastern ◽  
Moesian Platform ◽  
Shallow Subtidal ◽  
Carbonate Deposits

The most representative subsurface section of the Famennian carbonate succession from the Moesian Platform in Bulgaria occurs in the R-2 Preslavtsi well. Nine microfacies types (MFTs 1–9) have been distinguished and described in the intraclastic and peloidal limestone unit and the organogenic limestone unit. They are grouped in four microfacies associations: 1) protected shallow subtidal (lagoon) (MFT 1, bioclastic-peloidal packstone/grainstone; and MFT 2, oncoidal wackestone); 2) wave-dominated shallow subtidal (MFT 3, intraclastic-peloidal grainstone and rudstone; MFT 4, oncoidal rudstone; MFT 5, peloidal-bioclastic packstone and grainstone); 3) reef (MFT 6, solenoporacean-calcimicrobial-stromatoporoid boundstone; MFT 7, crinoid-stromatoporoid floatstone); and 4) open-marine (MFT 8, bioclastic wackestone/packstone with intraclasts and peloids; and MFT 9, bioclastic wackestone and packstone). The carbonate deposits are interpreted as formed in various shallow- to open-marine environments at or above the fair-weather wave base (MFTs 1–7) and below it (MFTs 8 and 9). Most of the described microfacies are comparable with Wilson’s (1975) Standard Microfacies Types.

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