scholarly journals Colonization and growth of crustose coralline algae (Corallinales, Rhodophyta) on the Rocas Atoll

2005 ◽  
Vol 53 (3-4) ◽  
pp. 147-156 ◽  
Author(s):  
Alexandre Bigio Villas Bôas ◽  
Marcia A. de O. Figueiredo ◽  
Roberto Campos Villaça

Crustose coralline algae play a fundamental role in reef construction all over the world. The aims fo this study were to identify and estimate the abundance of the dominant crustose coralline algae in shallow reef habitats, measuring their colonization, growth rates and productivity. Crusts sampled from different habitats were collected on leeward and windward reefs. Discs made of epoxy putty were fixed on the reef surface to follow coralline colonization and discs containing the dominant coralline algae were fixed on different habitats to measure the crusts' marginal growth. The primary production experiments followed the clear and dark bottle method for dissolved oxygen reading. Porolithon pachydermum was confirmed as the dominant crustose coralline alga on the Rocas Atoll. The non-cryptic flat form of P. pachydermum showed a faster growth rate on the leeward than on the windward reef. This form also had a faster growth rate on the reef crest (0.05 mm.day-1) than on the reef flat (0.01 mm.day-1). The cryptic protuberant form showed a trend, though not significant, towards a faster growth rate on the reef crest and in tidal pools than on the reef flat. Colonization was, in general, very slow as compared to that presented by other reef studies. P. pachydermum was a productive crust both in non-cryptic and cryptic habitats.

Geology ◽  
2019 ◽  
Vol 48 (3) ◽  
pp. 226-230 ◽  
Author(s):  
P.T.W. Chan ◽  
J. Halfar ◽  
W.H. Adey ◽  
P.A. Lebednik ◽  
R. Steneck ◽  
...  

Abstract Warming surface ocean temperatures combined with the continued diffusion of atmospheric CO2 into seawater have been shown to have detrimental impacts on calcareous marine organisms in tropical and temperate localities. However, greater oceanic CO2 uptake in higher latitudes may present a higher oceanic acidification risk to carbonate organisms residing in Arctic and subarctic habitats. This is especially true for crustose coralline algae that build their skeletons using high-Mg calcite, which is among the least stable and most soluble of the carbonate minerals. Here we present a century-long annually resolved growth, density, and calcification rate record from the crustose coralline alga Clathromorphum nereostratum, a dominant calcifier in Pacific Arctic and subarctic benthic communities. Specimens were collected from the Aleutian Islands, Alaska (USA), a region that has undergone a long-term decline of 0.08 ± 0.01 pH units since the late 19th century. Growth and calcification rates remain relatively stable throughout the record, but skeletal densities have declined substantially since A.D. 1983. Strong correlations to warming sea-surface temperatures indicate that temperature stress may play a significant role in influencing the ability of corallines to calcify. Decreasing algal skeletal density may offset the benefits of continued growth and calcification due to a weakening in structural integrity, which could have detrimental consequences for the diverse reef-like communities associated with algal structures in mid-to-high latitudes.


2021 ◽  
Vol 12 ◽  
Author(s):  
Fangfang Yang ◽  
Zhiliang Xiao ◽  
Zhangliang Wei ◽  
Lijuan Long

Crustose coralline algae (CCA) play vital roles in producing and stabilizing reef structures and inducing the settlement and metamorphosis of invertebrate larvae in coral reef ecosystems. However, little is known about the bacterial communities associated with healthy and bleached CCA and their interactions with coral larval settlement. We collected samples of healthy, middle semi-bleached, and bleached CCA Porolithon onkodes from Sanya Bay in the South China Sea and investigated their influences on the larval settlement and metamorphosis of the reef-building coral Pocillopora damicornis. The larval settlement/metamorphosis rates all exceeded 70% when exposed to healthy, middle semi-bleached, and bleached algae. Furthermore, the compositions of bacterial community using amplicon pyrosequencing of the V3–V4 region of 16S rRNA were investigated. There were no obvious changes in bacterial community structure among healthy, middle semi-bleached, and bleached algae. Alphaproteobacteria, Bacteroidetes, and Gammaproteobacteria were dominant in all samples, which may contribute to coral larval settlement. However, the relative abundances of several bacterial communities varied among groups. The relative abundances of Mesoflavibacter, Ruegeria, Nautella, and Alteromonas in bleached samples were more than double those in the healthy samples, whereas Fodinicurvata and unclassified Rhodobacteraceae were significantly lower in the bleached samples. Additionally, others at the genus level increased significantly from 8.5% in the healthy samples to 22.93% in the bleached samples, which may be related to algal bleaching. These results revealed that the microbial community structure associated with P. onkodes generally displayed a degree of stability. Furthermore, bleached alga was still able to induce larval settlement and metamorphosis.


This present study makes an analysis of changing contribution of sub-sector and composition and growth performance in Indian economy. In addition to that, the contribution of sub-sector of service sector in state economy. The results revealed that the growth rate of Chandigarh was high due to providing especial emphasis on dominating sub-sectors of services and its most preferred destination for technology whereas, Sikkim and Arunachal Pradesh due to geographical and environmental conditions development were higher in floriculture and agriculture, although, tourism emerged as a new profession and have different opportunities. Apart of that, in the wake of some challenges in the form of lack of infrastructure, recent crisis in the world market, foreign direct investment (FDI) restrictions and outsourcing backlash were major limiting factor.


Coral Reefs ◽  
2021 ◽  
Author(s):  
Alexandra Ramírez-Viaña ◽  
Guillermo Diaz-Pulido ◽  
Rocío García-Urueña

2005 ◽  
Vol 51 (1-4) ◽  
pp. 415-427 ◽  
Author(s):  
Lindsay Harrington ◽  
Katharina Fabricius ◽  
Geoff Eaglesham ◽  
Andrew Negri

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ilse Valenzuela Matus ◽  
Jorge Lino Alves ◽  
Joaquim Góis ◽  
Augusto Barata da Rocha ◽  
Rui Neto ◽  
...  

Purpose The purpose of this paper is to prove and qualify the influence of textured surface substrates morphology and chemical composition on the growth and propagation of transplanted corals. Use additive manufacturing and silicone moulds for converting three-dimensional samples into limestone mortar with white Portland cement substrates for coral growth. Design/methodology/approach Tiles samples were designed and printed with different geometries and textures inspired by nature marine environment. Commercial coral frag tiles were analysed through scanning electron microscopy (SEM) to identify the main chemical elements. Raw materials and coral species were selected. New base substrates were manufactured and deployed into a closed-circuit aquarium to monitor the coral weekly evolution process and analyse the results obtained. Findings Experimental results provided positive statistical parameters for future implementation tests, concluding that the intensity of textured surface, interfered favourably in the coralline algae biofilm growth. The chemical composition and design of the substrates were determinant factors for successful coral propagation. Recesses and cavities mimic the natural rocks aspect and promoted the presence and interaction of other species that favour the richness of the ecosystem. Originality/value Additive manufacturing provided an innovative method of production for ecology restoration areas, allowing rapid prototyping of substrates with high complexity morphologies, a critical and fundamental attribute to guarantee coral growth and Crustose Coralline Algae. The result of this study showed the feasibility of this approach using three-dimensional printing technologies.


2019 ◽  
Vol 5 (1) ◽  
pp. 1-26 ◽  
Author(s):  
Valeriy V. Mironov ◽  
Liudmila D. Konovalova

The article considers the problem of the relationship of structural changes and economic growth in the global economy and Russia in the framework of different methodological approaches. At the same time, the paper provides the analysis of complementarity of economic policy types, which, on the one hand, are aimed at developing the fundamentals of GDP growth (institutions, human capital and macroeconomic stabilization), and on the other hand, at initiating growth (with stable fundamentals) with the help of structural policy measures. In the study of structural changes in the global economy, new forms of policies of this kind have been revealed, in particular aimed at identifying sectors — drivers of economic growth based on a portfolio approach. In a given paper a preliminary version of the model of the Russian economy is provided, using a multisector version of the Thirlwall’s Law. Besides, the authors highlight a number of target parameters of indicators of competitiveness of the sectors of the Russian economy that allow us to expect its growth rate to accelerate above the exogenously given growth rate of the world economy.


ICR Journal ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 97-100
Author(s):  
Shahino Mah Abdullah

The most frequent transboundary haze in the world takes place in Southeast Asia. It is usually caused by land-use changes, open burning, peat combustion, wildfires, and other farming activities. Serious haze occurred in 1983, 1997, 2005, 2006, 2009, 2010, 2013, 2015 and 2016, originating from large-scale forest fires in western Sumatra and southern Kalimantan, Indonesia. It caused adverse effects to locals as well as neighbouring countries, affecting their health, economy, agriculture, and biodiversity. Among the serious effects of haze are increased respiratory-related mortality due to toxic airborne particles, jet crashs and ship collisions due to restricted visibility, reduction of crop growth rate due to limited solar radiation, and extinction of endangered primates due to habitat loss. Neighbouring countries like Malaysia and Singapore sometimes have to close schools to prevent people from being exposed to air pollution, and its consequent respiratory ailments.  


2016 ◽  
Author(s):  
Merinda C. Nash ◽  
Sophie Martin ◽  
Jean-Pierre Gattuso

Abstract. Red calcareous coralline algae are thought to be among organisms the most vulnerable to ocean acidification due to the high solubility of their magnesium calcite skeleton. Although, skeletal mineralogy is proposed to change as CO2 and temperature continues rising, there is currently very little information available on the response of coralline algal carbonate mineralogy to near-future changes in pCO2 and temperature. Here we present results from a one-year controlled laboratory experiment to test mineralogical responses to pCO2 and temperature in the Mediterranean crustose coralline alga (CCA) Lithophyllum cabiochae. Our results show that Mg incorporation is mainly constrained by temperature (+1 mol% MgCO3 for an increase of 3 °C) and there was no response to pCO2. This suggests that L. cabiochae thalli have the ability to buffer calcifying medium against ocean acidification, enabling them to continue to deposit Mg-calcite with a significant mol% MgCO3 under elevated pCO2. Analyses of CCA dissolution chips showed a decrease in Mg content after 1 year for all treatments but this was not affected by pCO2 nor by temperature. Our findings suggest that biological processes exert a strong control on calcification on Mg-calcite and that CCA may be more resilient under rising CO2 than previously thought. However, previously demonstrated increased skeletal dissolution with ocean acidification will still have major consequences for the stability and maintenance of Mediterranean coralligenous habitats.


Sign in / Sign up

Export Citation Format

Share Document