scholarly journals Are coral reefs victims of their own past success?

2016 ◽  
Vol 2 (4) ◽  
pp. e1500850 ◽  
Author(s):  
Willem Renema ◽  
John M. Pandolfi ◽  
Wolfgang Kiessling ◽  
Francesca R. Bosellini ◽  
James S. Klaus ◽  
...  
Keyword(s):  
Coral Reefs ◽  
High Growth ◽  
Local Stress ◽  
High Amplitude ◽  
Anthropogenic Change ◽  
Large Role ◽  
Sea Level Fluctuations ◽  
The Past ◽  
Anthropogenic Stressors ◽  
Coral Abundance

As one of the most prolific and widespread reef builders, the staghorn coral Acropora holds a disproportionately large role in how coral reefs will respond to accelerating anthropogenic change. We show that although Acropora has a diverse history extended over the past 50 million years, it was not a dominant reef builder until the onset of high-amplitude glacioeustatic sea-level fluctuations 1.8 million years ago. High growth rates and propagation by fragmentation have favored staghorn corals since this time. In contrast, staghorn corals are among the most vulnerable corals to anthropogenic stressors, with marked global loss of abundance worldwide. The continued decline in staghorn coral abundance and the mounting challenges from both local stress and climate change will limit the coral reefs’ ability to provide ecosystem services.

scholarly journals Common Starling Sturnus vulgaris expansion in South Africa

2018 ◽  
Vol 9 ◽  
Author(s):  
Ielyzaveta M. Ivanova ◽  
Craig T. Symes
Keyword(s):  
South Africa ◽  
Sturnus Vulgaris ◽  
Anthropogenic Change ◽  
Gauteng Province ◽  
The Past ◽  
Entire Country ◽  
The Face ◽  
The Common ◽  
Potential Impact ◽  
Using Data

The Common Starling Sturnus vulgaris has progressively expanded its range in South Africa since its introduction into Cape Town in the late 19th century. In the past few decades it has extended this range into Gauteng province. Using data from the Southern African Bird Atlas Project 2, this paper examines the spread and relative abundance changes for the species across South Africa over the past 10 years, with a detailed look at the recently-colonised Gauteng. Across South Africa, the Common Starling's distribution has shifted, and grown. As it spreads north along the coastline and northwards inland, some of the former range has been lost. In Gauteng, the species has shown a range and abundance expansion over the same period. If the observed trends are to continue, this species is likely to eventually become a prominent species across the entire country, and further north into the sub-region. However, the potential impact that this species has on indigenous avifauna is unknown and, in the face of rapid anthropogenic change, remains to be investigated.

scholarly journals Coral mortality induced by the 2015–2016 El-Niño in Indonesia: the effect of rapid sea level fall

2017 ◽  
Vol 14 (4) ◽  
pp. 817-826 ◽  
Author(s):  
Eghbert Elvan Ampou ◽  
Ofri Johan ◽  
Christophe E. Menkes ◽  
Fernando Niño ◽  
Florence Birol ◽  
...  
Keyword(s):  
Coral Reefs ◽  
Sea Level ◽  
El Niño ◽  
Reef Flat ◽  
El Nino ◽  
Differential Mortality ◽  
Altimetry Data ◽  
Bathymetric Range ◽  
The Past ◽  
Coral Genus

Abstract. The 2015–2016 El-Niño and related ocean warming has generated significant coral bleaching and mortality worldwide. In Indonesia, the first signs of bleaching were reported in April 2016. However, this El Niño has impacted Indonesian coral reefs since 2015 through a different process than temperature-induced bleaching. In September 2015, altimetry data show that sea level was at its lowest in the past 12 years, affecting corals living in the bathymetric range exposed to unusual emersion. In March 2016, Bunaken Island (North Sulawesi) displayed up to 85 % mortality on reef flats dominated by Porites, Heliopora and Goniastrea corals with differential mortality rates by coral genus. Almost all reef flats showed evidence of mortality, representing 30 % of Bunaken reefs. For reef flat communities which were living at a depth close to the pre-El Niño mean low sea level, the fall induced substantial mortality likely by higher daily aerial exposure, at least during low tide periods. Altimetry data were used to map sea level fall throughout Indonesia, suggesting that similar mortality could be widespread for shallow reef flat communities, which accounts for a vast percent of the total extent of coral reefs in Indonesia. The altimetry historical records also suggest that such an event was not unique in the past two decades, therefore rapid sea level fall could be more important in the dynamics and resilience of Indonesian reef flat communities than previously thought. The clear link between mortality and sea level fall also calls for a refinement of the hierarchy of El Niño impacts and their consequences on coral reefs.

scholarly journals Marine and freshwater taxa: some numerical trends

2019 ◽  
Vol 6 (2) ◽  
Author(s):  
Semyon Ya. Tsalolikhin ◽  
Aldo Zullini
Keyword(s):  
Sea Level ◽  
Benthic Fauna ◽  
Marine Species ◽  
Inland Waters ◽  
Sea Level Fluctuations ◽  
The Past ◽  
Freshwater Fauna

Most of the freshwater fauna originates from ancient or recent marine ancestors. In this study, we considered only completely aquatic non-parasitic animals, counting 25 phyla, 77 classes, 363 orders for a total that should include 236,070 species. We divided these taxa into three categories: exclusively marine, marine and freshwater, and exclusively freshwater. By doing so, we obtained three distribution curves which could reflect the marine species’ mode of invasion into continental waters. The lack of planktonic stages in the benthic fauna of inland waters, in addition to what we know about the effects of the impoundment of epicontinental seas following marine regressions, lead us to think that the main invasion mode into inland waters is more linked to the sea level fluctuations of the past than to slow and “voluntary” ascents of rivers by marine elements.

Has Nitrogen Supply to Coral Reefs in the South Pacific Ocean Changed Over the Past 50 Thousand Years?

2019 ◽  
Vol 34 (4) ◽  
pp. 567-579
Author(s):  
Dirk V. Erler ◽  
Benjamin O. Shepherd ◽  
Braddock K. Linsley ◽  
Luke D. Nothdurft ◽  
Quan Hua ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
Coral Reefs ◽  
South Pacific ◽  
Nitrogen Supply ◽  
The South ◽  
The Past ◽  
South Pacific Ocean

Paper 4: Opening, Carding and Spinning Preparation Machines

1966 ◽  
Vol 181 (12) ◽  
pp. 1-7
Author(s):  
H. Catling
Keyword(s):  
High Speed ◽  
Unit Length ◽  
High Amplitude ◽  
Torsional Vibrations ◽  
Stick Slip ◽  
Periodic Disturbance ◽  
The Past ◽  
Machine Utilization ◽  
Lubrication Conditions ◽  
New Machine

There are no serious bearing problems in opening and carding machines. Except for the high-speed beaters and cylinders, occasionally-oiled plain journals were long regarded as adequate despite the fact that many of them operated under boundary lubrication conditions. Stable hydrodynamic film conditions were maintained in beater and cylinder bearings and some simple form of lubricant reservoir was usually provided. In recent years the introduction of shift working and high machine utilization factors have led to a demand for machines requiring a minimum of attention. This demand is being met by the use of prepacked, sealed ball or roller bearings at all points. Perhaps the most serious and intractable bearing problem in the whole field of textile machinery manufacture is encountered in drawframes and speedframes. For uniformity of the drawing action by which the fibres are straightened and finally attenuated to form a roving, it is necessary for all the drafting rollers to rotate perfectly smoothly. Unfortunately the loading conditions and the rotational speeds of some of the rollers are such that there is often a high liability to the occurrence of spontaneous stick–slip torsional vibrations. In other cases there is an incipient liability to stick–slip vibration and quite small gearing faults, of the appropriate frequency, are sufficient to precipitate high amplitude oscillations. At the frequencies commonly observed the non-uniformity of the drawing action introduces into the sliver or roving a periodic disturbance of a wavelength so short that it is not readily apparent in the delivery from the affected machine. Subsequent drafting, however, increases the wavelength and the ultimate yarn exhibits appreciable variations in mass per unit length and in twist distribution. As these variations are strictly periodic they form objectionable interference patterns when used as weft in either woven or knitted cloths. New machine designs and the use of new types of bearings have largely solved these problems and at the same time greatly increased operating speeds. The comber, too, has been intensively developed during the past ten years and a number of lubrication and wear problems have required attention.

The Late Cenozoic evolution of the Aksu basin (Isparta Angle; SW Turkey). New insights

2011 ◽  
Vol 182 (2) ◽  
pp. 133-148 ◽  
Author(s):  
André Poisson ◽  
Fabienne Orszag-Sperber ◽  
Erdal Kosun ◽  
Maria-Angella Bassetti ◽  
Carla Müller ◽  
...  
Keyword(s):  
Coral Reefs ◽  
Normal Faults ◽  
The West ◽  
Shallow Marine ◽  
Northern Margin ◽  
Sea Level Fluctuations ◽  
Marine Deposits ◽  
The North ◽  
Sw Turkey ◽  
Isparta Angle

Abstract The Mio-Pliocene basins around the Antalya gulf in SW Turkey developed above the Tauric Mesozoic platforms on which the Antalya nappes had been thrusted (in Late Cretaceous-Paleocene times). The closure of the initial Isparta Angle during these events (E-W compression) initiated the N-S orientation of the main structural lines, which persisted later and explains the orientation of the Aksu basin in contrast with the E-W orientation of the eastern Neo-gene Mediterranean basins. The area, and all southwestern Turkey, became emergent at the end of the Oligocene and were the site of shallow-marine carbonate deposits in the Chattian-Aquitanian, giving way to the wide Lycian basin in Burdigalian-Langhian times. The progressive emplacement of the Lycian nappes from the north over this basin provoked first its subsidence and then its emersion when the nappes attained their final position over the Bey Daglari platform in Langhian times. Coinciding, or in response to the Lycian nappes emplacement, the Aksu basin was initiated as an elongated N-S graben which was filled by thick accumulations of terrestrial and marine deposits(including coral reefs), which derived from the erosion of the Lycian allochton and its basement (Langhian?, Serravallian and Tortonian times). The syn-sedimentary tectonics : reactivation of the normal faults along the west margin of the basin, the continuous uplift of the neighbouring continental areas (beginning of the Aksu thrust), governed the geometry of the basin. As a result and due to the uplift of its northern margin, the Aksu basin migrated towards the south and in Messinian times it was reduced to a narrow gulf along the eastern margin of which the Gebiz limestones were deposited as fringing coral reefs. The age of these limestones has been debated. Our new data allow us to attribute them to the Messinian. The drastic retreat of the sea at the end of this period, provoked the erosion of large parts of the Messinian deposits and the formation of deep canyons on land and under the sea down to the Antalya abyssal plain, in which evaporites were deposited. During the Zanclean transgression, the Eskiköy-Kargi canyon was filled by coarse clastics of a Gilbert delta derived from the northern continental area following a model well known elsewhere in the Mediterranean basins. Southward, shallow-marine sands and marls unconformably cover the remnants of the Messinian deposits and the emergent areas of the southern Antalya gulf. After Zanclean times (end of Pliocene?), the Aksu basin was deformed, due to the west-directed Aksu compressional event (end of the Aksu thrust). Quaternary terraces of the Aksu river at various altitudes, as well as the terraces of the Antalya tufa can be related to sea level fluctuations.

Primacy of bottom-up effects on a butterflyfish assemblage

2016 ◽  
Vol 67 (8) ◽  
pp. 1175 ◽  
Author(s):  
Susannah M. Leahy ◽  
Garry R. Russ ◽  
Rene A. Abesamis
Keyword(s):  
Climate Change ◽  
Water Quality ◽  
Coral Reefs ◽  
Fisheries Management ◽  
Negative Association ◽  
Feeding Guilds ◽  
Top Down ◽  
Management Tools ◽  
Bottom Up ◽  
Anthropogenic Stressors

The question of whether biological systems are maintained by top-down versus bottom-up drivers is a recurring one in ecology. It is a particularly important question to address in the management of coral reefs, which are at risk from a variety of anthropogenic stressors. Here, we explicitly test whether the abundance of different feeding guilds of coral-associated Chaetodon butterflyfishes are controlled by top-down or bottom-up drivers, and we assess the relative influence of all statistically significant drivers. We find that the abundance and species richness of Chaetodon butterflyfishes are predominately determined by bottom-up drivers. The abundance of corallivores is primarily driven by availability of branching and tabular live corals, whereas the abundance of generalists is most strongly influenced by a negative association with macroalgal cover. We also find evidence of weak top-down control on the abundance of corallivorous butterflyfish by gape-limited mesopredators, but no such effects on generalist butterflyfish. Our findings indicate that conservation of coral reefs for Chaetodon butterflyfishes must include management at a larger spatial scale in order to reduce the effect of coral reef stressors such as declining water quality and climate change, but should also include implementation of fisheries management tools in order to increase local herbivory.

Review: Research progress in amur grape, Vitis amurensis Rupr.

2013 ◽  
Vol 93 (4) ◽  
pp. 565-575 ◽  
Author(s):  
Liyuan Liu ◽  
Hua Li
Keyword(s):  
High Growth ◽  
White Rot ◽  
Research Progress ◽  
Vitis Amurensis ◽  
The Past ◽  
Natural Substances ◽  
Red Color ◽  
Sweet Wines ◽  
Resistant Rootstock ◽  
Growth Vigor

Liu, L. Y. and Li, H. 2013. Review: Research progress in amur grape, Vitis amurensis Rupr. Can. J. Plant Sci. 93: 565–575. Vitis amurensis Rupr., which originates in China and has several important traits, such as cold- and disease-resistance, is now commercially cultivated in China. Vitis amurensis has a strong root system and high growth vigor allowing it to survive temperatures as low as −40°C without the need to bury its vines, saving inputs in vineyard management. During growth, V. amurensis vines have high resistance to many diseases, such as grape white rot and grape anthracnose, and are thus often used as a disease-resistant stock as well as the most powerful cold-resistant rootstock to breed materials for novel cultivars. As a wine grape, the fruit fragrance and distinctive taste are unique for making high quality red and sweet wines, which have a brilliant ruby red color, fine fragrance, and a full-bodied and distinctive taste. Vitis amurensis grapes and the wines made from them contain abundant bioactive natural substances, which have important effects on lowering human blood pressure, antioxidation, anti-aging, cardiovascular disease prevention, etc. The present article addresses research progress and the utilization of V. amurensis achieved in the past decades. Further studies are proposed.

The near future of coral reefs

2002 ◽  
Vol 29 (4) ◽  
pp. 460-483 ◽  
Author(s):  
Timothy R. McClanahan
Keyword(s):  
Coral Reefs ◽  
Sea Urchins ◽  
Trophic Levels ◽  
Current Status ◽  
Toxic Substances ◽  
Atmospheric Concentration ◽  
Seawater Chemistry ◽  
Generalist Species ◽  
The Past ◽  
Use Of Resources

In this paper the current status of coral reefs, predictions concerning the ecological state of coral reefs to the 2025 time horizon and the research needs that can help understanding and management activities that might alleviate detrimental ecological changes are evaluated and discussed. The present rate of CO2 emissions will produce an atmospheric concentration in 100 years not experienced during the past 20 million years and water temperatures above those of the past interglacial 130 000 years before present. Human influences on water temperatures, seawater chemistry (toxic substances, nutrients and aragonite saturation), the spread of diseases, removal of species and food web alterations are presently changing reef ecology. A significant ecological reorganization is underway and changes include a reduction in calcifying and zooxanthellae-hosting organisms, their obligate symbionts, and species at higher trophic levels, with an increase in generalist species of low trophic level that are adapted to variable environments. Late-successional fleshy brown algae of low net productivity or non-commercial invertebrates such as sea urchins, starfish and coral-eating snails will dominate many reefs. These changes will be associated with a loss of both net benthic and fisheries production and inorganic carbonate deposition; this will reduce reef complexity, species richness, reef growth and increase shoreline erosion. To avert these changes management is needed at both global and local levels. Both levels need to reduce greenhouse gases and other waste emissions and renew efforts to improve resource management including restrictions on the use of resources and globalization of resource trade, run-off and waste production, and balancing potential reef production and resource consumption.

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