Human impact on a small barrier reef meadow of Posidonia oceanica (L.) Delile on the north Tyrrhenian coast (Italy)

2013 ◽  
Vol 77 (1-2) ◽  
pp. 45-54 ◽  
Author(s):  
Lenzi Mauro ◽  
Gennaro Paola ◽  
Volterrani Margherita ◽  
Roffilli Rugiada ◽  
Birardi Francesca ◽  
...  
Keyword(s):  
Human Impact ◽  
Posidonia Oceanica ◽  
Barrier Reef ◽  
The North

MONITORING THE DYNAMICS OF THERMOABRASION COASTS AT KHARASAVEY AREA, WESTERN YAMAL (KARA SEA)

2017 ◽  
Author(s):  
Dmitry Kuznetsov ◽  
Dmitry Kuznetsov ◽  
Anatoliy Kamalov ◽  
Anatoliy Kamalov ◽  
Nataliya Belova ◽  
...  
Keyword(s):  
Human Impact ◽  
Remote Sensing Data ◽  
Kara Sea ◽  
Motor Vehicles ◽  
Yamal Peninsula ◽  
Western Coast ◽  
Frozen Ground ◽  
Coastal Dynamics ◽  
The North ◽  
Ice Content

The dynamics of thermoabrasion coasts on loose sediments under permafrost conditions are highly variable due to several factors: length of the dynamic period of the year, mechanic composition of the frozen ground and its ice content, hydrometeorological conditions, and human impact. Multiannual monitoring of the coastal zone was carried out by Lab. Geoecology of the North (Moscow State University) at the 22 km long Kharasavey deposit site, Western Coast of Yamal Peninsula (Kara Sea). The methods include direct measurements and observations (repeated topographic survey of shore transects from 1981 to 2012) along with remote sensing data analysis (images from 1964 to 2011). This allowed producing detailed characteristics of coastal dynamics. At the site, thermoabrasion coasts occupy the most part, and accumulative coasts are present in the north. Data on natural relief forming factors and ground composition are included in the detailed geomorphologic map of the site. Shore retreat rate shows correlation to amounts of wind-wave energy and to specific wind directions. Human impact on the coast includes dredging at the port channel, mining of sand, driving motor vehicles, and deposition of construction debris. Relations between shore retreat rate and aforementioned factors were studied, including dependencies on ice content, and shore segmentation was carried out. This allows for coastal dynamics forecasts in the region.

The mapping of the Posidonia oceanica (L.) Delile barrier reef meadow in the southeastern Gulf of Tunis (Tunisia)

2016 ◽  
Vol 121 ◽  
pp. 358-364 ◽  
Author(s):  
Mohamed Amine Hachani ◽  
Boutheina Ziadi ◽  
Habib Langar ◽  
Djallouli Aslem Sami ◽  
Souad Turki ◽  
...  
Keyword(s):  
Posidonia Oceanica ◽  
Barrier Reef ◽  
Gulf Of Tunis

scholarly journals Climatic variability and human impact during the last 2000 years in western Mesoamerica: evidence of late Classic (AD 600–900) and Little Ice Age drought events

2015 ◽  
Vol 11 (9) ◽  
pp. 1239-1248 ◽  
Author(s):  
A. Rodríguez-Ramírez ◽  
M. Caballero ◽  
P. Roy ◽  
B. Ortega ◽  
G. Vázquez-Castro ◽  
...  
Keyword(s):  
Human Impact ◽  
Little Ice Age ◽  
Climatic Variability ◽  
Seasonal Migration ◽  
Ice Age ◽  
Cultural Tradition ◽  
Late Classic ◽  
High Pressure Cell ◽  
Western Mexico ◽  
The North

Abstract. We present results of analysis of biological (diatoms and ostracodes) and non-biological (Ti, Ca / Ti, total inorganic carbon, magnetic susceptibility) variables from an 8.8 m long, high-resolution (~ 20 yr sample−1) laminated sediment sequence from Lake Santa María del Oro (SMO), western Mexico. This lake lies at a sensitive location between the dry climates of northern Mexico, under the influence of the North Pacific subtropical high-pressure cell and the moister climates of central Mexico, under the influence of the seasonal migration of the intertropical convergence zone and the North American monsoon (NAM). The sequence covers the last 2000 years and provides evidence of two periods of human impact in the catchment, shown by increases in the diatom Achnanthidium minutissimum. The first from AD 100 to 400 (Early Classic) is related to the shaft and chamber tombs cultural tradition in western Mexico, and the second is related to Post-Classic occupation from AD 1100 to 1300. Both periods correspond to relatively wet conditions. Three dry intervals are identified from increased carbonate and the presence of ostracodes and aerophilous Eolimna minima. The first, from AD 500 to 1000 (most intense during the late Classic, from AD 600 to 800), correlates with the end of the shaft and chamber tradition in western Mexico after ca. AD 600. This late Classic dry period is the most important climatic signal in the Mesoamerican region during the last 2000 years, and has been recorded at several sites from Yucatan to the Pacific coast. In the Yucatan area, this dry interval has been related with the demise of the Maya culture at the end of the Classic (AD 850 to 950). The last two dry events (AD 1400 to 1550 and 1690 to 1770) correspond with the onset of, and the late, Little Ice Age, and follow largely the Spörer and Maunder minima in solar radiation. The first of these intervals (AD 1400 to 1550) shows the most intense signal over western Mexico; however this pattern is different at other sites. Dry/wet intervals in the SMO record are related with lower/higher intensity of the NAM over this region, respectively.

The Ecology and Distribution of Intertidal Organisms on Certain Islands off the Queensland Coast

1956 ◽  
Vol 7 (3) ◽  
pp. 317 ◽  
Author(s):  
R Endean ◽  
W Stephenson ◽  
R Kenny
Keyword(s):  
Species Composition ◽  
Great Barrier Reef ◽  
Gradual Transition ◽  
Barrier Reef ◽  
Marine Fauna ◽  
The North ◽  
Specific Composition ◽  
Continental Islands ◽  
Longitudinal Division ◽  
Zonation Patterns

The species composition and general ecology of intertidal organisms present at Heron Island, a coral cay in the Capricorn Group, are recorded in this paper. It was found that the general zonation picture on this Great Barrier Reef island differed markedly from that found previously at localities on the Queensland mainland (Endean, Kenny, and Stephenson 1956). In particular the mainland upper barnacle (Chthamalus) zone was not represented at Heron I., and the species forming the mainland lower barnacle zone (Tetraclita squamosa (Bruguiere) ) was replaced by a different species (Tetraclita vitiata Darwin). Also the characteristic algal zone of mainland localities was replaced by a lithothamnion-zoanthid-coral zone. In order to investigate the possibility of a gradual transition from the mainland type zonation to that found on the Great Barrier Reef, as exemplified by Heron I. zonation, the species composition and general ecology of intertidal organisms inhabiting a series of continental islands lying off the Queensland coast between lat. 16� and 22� S. were investigated. The fauna of these islands was found to be closely allied to that of the mainland. There was, however, an intrusion of corals and zoanthids on the more exposed of the islands visited which lie between lat. 20� and 22�S., and also on the more northerly of the islands visited. The biogeographical implications of these findings are discussed, and it is noted that the results of the present investigation support the contention of Whitley (1932) that a longitudinal division of the Queensland marine fauna into "Solanderian" and "Banksian" elements is warranted. Accounts are also given of the major environmental factors that might affect specific composition and zonation patterns at the localities investigated. Analyses of these have given much information on the general ecology and distribution of many Queensland intertidal species. Thls information is discussed. Of particular interest was the finding that the Peronian barnacle Tetraclita rosea (Krauss) has extended its range,to the north of the biogeographical boundary situated near lat. 25� S. by colonizing the more exposed of the continental islands.

The Big Map

2021 ◽  
pp. 168-190
Author(s):  
Brad Edmondson
Keyword(s):  
Land Use ◽  
Human Impact ◽  
State Legislature ◽  
The State ◽  
Adirondack Park ◽  
Board Members ◽  
Legal Requirements ◽  
The North ◽  
Land Use Plan ◽  
Boundary Lines

This chapter tells the story of how the early Adirondack Park Agency (APA) struggled to meet the state's assignments. It details what the state legislature gave to the early APA: an extremely ambitious to-do list and a ridiculously small budget. Much of the work depended on the men who had also worked for the Temporary Study Commission (TSC). The chapter analyses the story of George Davis who turned the idea for his dissertation into a big map that transformed life in the North Country. Davis's passion was protecting land that he thought should remain free of human impact. His thesis would compile data to show which Adirondack lands were suitable for development and which should remain undisturbed. The chapter then shifts with the APA chairman, Richard Lawrence who overcame opposition on several fronts as he struggled to maintain a working majority of board members, and the tireless work of Peter Paine, a well-connected lawyer, who argued stridently for the two plans. Ultimately, the chapter explains the significance of the APA map project. It argues that map making was important because the legal requirements for the land use plan were unusual, as most land use laws use text to describe the boundary lines of the area being regulated.

Water circulation and shelf waves in the northern Great Barrier Reef lagoon

1981 ◽  
Vol 32 (5) ◽  
pp. 721 ◽  
Author(s):  
E Wolanski ◽  
B Ruddick
Keyword(s):  
Great Barrier Reef ◽  
Sea Level ◽  
Low Frequency ◽  
Current Data ◽  
Barrier Reef ◽  
Sea Levels ◽  
The North ◽  
Level Data ◽  
Shelf Wave ◽  
Salinity Water

Currents and sea levels were measured at a number of locations in the Great Barrier Reef (GBR) lagoon from about 10 to 13� S., during the period October-December 1979. A strong non-tidal, low-frequency modulation of all sea-level and current data was found. The currents nearshore were driven northward by the wind, and then at least partially blocked by the dense network of reefs to the north of 10� s. The water then flowed southward in deeper water adjacent to the reef, driven by a longshore pressure gradient. The low- frequency sea-level data, though not the current records, showed northward phase propagation at speeds characteristic of a first-mode shelf wave trapped in the lagoon between the shore and the reef. Data are presented revealing the intrusion of low-salinity water, through Bligh Entrance, in the GBR lagoon, as a result of river discharges in the Gulf of Papua. It is suggested that low-frequency longshore currents may periodically flush these river plumes from the GBR lagoon and enhance interaction between reefs. In the Coral Sea in front of reef passages, the large horizontal velocities may result in forces upwelling by selective withdrawal and jet entrainment.

Physical properties of the Great Barrier reef Lagoon waters near Townsville. II. Seasonal variations

1981 ◽  
Vol 32 (3) ◽  
pp. 321 ◽  
Author(s):  
E Wolanski ◽  
M Jones ◽  
WT Williams
Keyword(s):  
Physical Properties ◽  
Great Barrier Reef ◽  
Seasonal Variations ◽  
High Salinity ◽  
Dry Season ◽  
Barrier Reef ◽  
Reef Lagoon ◽  
The North ◽  
Strong Winds ◽  
Calm Weather

The distribution of salinity, temperature, suspended particles, light transmissivity, chlorophyll a and phaeopigments across the Great Barrier Reef lagoon offshore Townsville, was measured from 9 January 1979 to 23 January 1980 at approximately weekly intervals. Previous observations at Low Isles. 400 km to the north, on seasonal variations of temperature and salinity were generally applicable here. A shallow summer thermocline was frequently observed in offshore waters, in the dry season and in calm weather. As a result of evaporation from the lagoon and adjoining mangrove swamps during the dry season, an inverse estuarine circulation can exist when high salinity, sediment-rich, nearshore waters sink below the less saline offshore waters. Only nearshore were bottom sediments strongly entrained in the water column during strong winds, principally in winter.

Torres Strait and the Inner Route

1977 ◽  
Vol 30 (1) ◽  
pp. 21-27
Author(s):  
J. H. S. Osborn
Keyword(s):  
Coral Reef ◽  
Great Barrier Reef ◽  
East Coast ◽  
Barrier Reef ◽  
Outer Limit ◽  
North East ◽  
The North ◽  
Torres Strait ◽  
Alternative Routes ◽  
Coral Reef System

The north-east coast of Australia is fronted by the world's longest coral reef system, which stretches in a north/south direction between latitudes 9° and 24° South. Although its outer limit is at distances of between 20 and 120 miles from the coast the enclosed waters are relatively shallow and contain many islands, detached reefs and shoals. The shipping lane between the coast and the Great Barrier Reef is known as the Inner Route. Torres Strait, its northern entrance, although extensive is shallow throughout and encumbered by reefs and islands to such an extent that only one route through it has been lit. The alternative routes are shallow or tortuous.

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