Sandy Beaches of Brazilian Oceanic Islands

2016 ◽  
pp. 543-571 ◽  
Author(s):  
Lauro Júlio Calliari ◽  
Pedro de Souza Pereira ◽  
Andrew D. Short ◽  
Fernando C. Sobral ◽  
Arthur A. Machado ◽  
...  
Keyword(s):  
Sandy Beaches ◽  
Oceanic Islands

Biodiversity of free-living marine nematodes on the coast of Brazil: a review

Zootaxa ◽  
2010 ◽  
Vol 2568 (1) ◽  
pp. 39 ◽  
Author(s):  
VIRÁG VENEKEY ◽  
VERÔNICA G. FONSECA-GENEVOIS ◽  
PAULO J. P. SANTOS
Keyword(s):  
Sandy Beaches ◽  
Oceanic Islands ◽  
Taxonomic Composition ◽  
Artificial Substrates ◽  
Rocky Shores ◽  
Coastal Habitats ◽  
Free Living ◽  
Generic Composition ◽  
Faunal List ◽  
First Time

The taxonomic richness of the marine Nematoda in coastal habitats of Brazil and similarities in generic composition among them are analysed. A complete faunal list is presented, containing 11 orders, 59 families, 294 genera and 231 species, among which 1 family, 10 genera and 87 species were discovered for the first time in Brazil. Seven habitats were considered (sandy beaches, estuaries, phytal, oceanic islands, beach rocks, salt works and artificial substrates): sandy beaches had the greatest generic richness (241), followed by estuaries (142) and the phytal environment (126). Taxonomic composition was similar to that of other coastal habitats sampled worldwide, with Chromadoridae and Xyalidae the most representative families. The three major habitats (beaches, rocky shores and estuaries), showed statistically significant differences in faunas. Estuaries were the most uniform in composition.

Petrography and provenance of beach sands from volcanic oceanic islands: Cabo Verde, Atlantic Ocean

2021 ◽  
Vol 91 (1) ◽  
pp. 92-115
Author(s):  
Emilia Le Pera ◽  
Consuele Morrone ◽  
José Arribas ◽  
M. Eugenia Arribas ◽  
Eumenio Ancochea ◽  
...  
Keyword(s):  
Morphological Evolution ◽  
Sandy Beaches ◽  
Oceanic Islands ◽  
Relative Increase ◽  
Lava Flows ◽  
Beach Sand ◽  
Carbonate Platforms ◽  
Cabo Verde ◽  
Beach Sands ◽  
Santiago Island

ABSTRACT Volcaniclastic deposits have been extensively analyzed in several settings in the Pacific and circum-Pacific area. Recent volcaniclastic products from Atlantic oceanic islands offer another opportunity to add new data and be an important key to a better understanding of volcanic imprints on the sedimentary record. The Cabo Verde archipelago is an Atlantic Oceanic plateau with late Oligocene to Holocene volcanism. Outcrops consist mainly of mafic and strongly alkaline and ultra-alkaline volcanic (pyroclastic and lava flows) and less abundant intrusive rocks with minor carbonatites and carbonate sedimentary rocks, constituting a multiple-provenance assemblage for the sandy beaches surrounding the islands. Currently, climate is semiarid to hyperarid with ephemeral and intermittent streams. Thirty-six samples of beach sand from six principal Cabo Verde Islands were selected for petrographic inspection. On average, beach sands constitute a volcanolithic petrofacies. A relative increase in carbonate limeclasts and bioclasts dilutes the pure volcaniclastic contribution mainly on the older island beaches (Sao Vicente, Sal, and Boa Vista). The major components of Cabo Verde beach sands are highly variable; in general, composition is a function of island morphological evolution and age. Thus, beaches of the younger islands (Sao Nicolau, Santiago, and Fogo) consist mainly of volcanic lithic fragments, and monomineralic grains of dense minerals such as olivine, pyroxene, and amphibole, and single grains of plagioclase and anorthoclase. By contrast, beaches of older eastern islands (Sal, Boa Vista, and Sao Vicente) contain more calcareous bioclasts, micritic and/or sparitic sedimentary lithic grains. The presence of carbonate grains suggests provenance from shallow carbonate platforms developed during periods of volcanic quiescence. Cabo Verde volcanic sandy fractions are composed mostly of black, brown, and orange glassy volcanic particles exhibiting microlitic, lathwork, and vitric textures. Volcanic particles with lathwork textures are linked to mafic provenance assemblages (nephelinites, basanites, and tephrites). The content of glassy particles is nearly constant in all beaches, and both hydroclastic and epiclastic processes are reflected in these populations of glassy grains. Boa Vista, Sao Vicente, and Santiago beaches contain higher proportions of sideromelane, linked to recent coastal volcanism, and lower proportions of orange and black glassy particles. The concentration of orange glass particles in the beaches of Santiago Island is higher than in the other island beaches. These orange glassy textures have been preserved even if they were sourced from the intensely altered Ancient Eruptive Complex, representing the pre-Miocene seamount stage of Santiago Island. A very small percentage of altered labile monocrystalline grains such as olivine and the paucity of altered volcanic components reflect the weathering-limited erosion regime of the islands. The exposed phonolitic lava flows that occupy only a minor surface part of the inland source produce particles with microlitic texture in sand beaches. Thus, this texture is not exclusive to andesitic, basaltic, and basaltic andesites sources, suggesting the need for a review of these particles as source-sensitive provenance signals.

Meiofauna and free-living nematodes in volcanic sands of a remote South Atlantic, oceanic island (Trindade, Brazil)

2017 ◽  
Vol 98 (8) ◽  
pp. 1919-1934 ◽  
Author(s):  
T.M.T. Santos ◽  
V. Venekey
Keyword(s):  
Sandy Beaches ◽  
Oceanic Islands ◽  
Oceanic Island ◽  
Spatial And Temporal Variation ◽  
East Atlantic ◽  
Free Living ◽  
Intertidal Zones ◽  
Deposit Feeders ◽  
Trindade Island ◽  
Meiofaunal Community

This study presents patterns of spatial and temporal variation in the meiofaunal community and nematode associations on the volcanic sandy beaches of Trindade Island, a remote oceanic island in the South-east Atlantic Ocean. Samples were collected in August (rainy season) and December 2014 (dry season) on four beaches (Tartarugas, Parcel, Cabritos and Portugueses) at three zones of the intertidal (high, mid and low). A total of 10 meiofaunal groups were found. Copepods (31%) and nematodes (27%) dominated the meiofauna in all beaches and zones, regardless of the season. Nematodes were comprised mainly of non-selective deposit feeders, with a total of 27 genera from 12 families, with Cyatholaimidae, Xyalidae and Oncholaimidae as the most diverse and abundant. Significant differences were found in the meiofaunal community, as well as in nematode associations, among seasons and intertidal zones but not among beaches. The sediment characteristics were the main drivers regulating the structure of meiobenthic fauna in Trindade Island. Our findings are also compared to other studies focusing on the meiofauna and nematodes of oceanic islands with carbonate and volcanic sediments; the major patterns are herein presented.

Systematics and evolution of Lentibulariaceae: III. Utricularia

2018 ◽  
Author(s):  
Richard W. Jobson ◽  
Paulo C. Baleeiro ◽  
Cástor Guisande
Keyword(s):  
Gene Flow ◽  
Species Diversity ◽  
Population Level ◽  
Oceanic Islands ◽  
Vulnerable Species ◽  
Phylogenetic Studies ◽  
Molecular Phylogenetic

Utricularia is a morphologically and ecologically diverse genus currently comprising more than 230 species divided into three subgenera—Polypompholyx, Utricularia, and Bivalvaria—and 35 sections. The genus is distributed worldwide except on the poles and most oceanic islands. The Neotropics has the highest species diversity, followed by Australia. Compared to its sister genera, Utricularia has undergone greater rates of speciation, which are linked to its extreme morphological flexibility that has resulted in the evolution of habitat-specific forms: terrestrial, rheophytic, aquatic, lithophytic, and epiphytic. Molecular phylogenetic studies have resolved relationships for 44% of the species across 80% of the sections. Scant data are available for phylogeography or population-level processes such as gene flow, hybridization, or pollination. Because nearly 90% of the species are endemics, data are urgently needed to determine how to protect vulnerable species and their habitats.

scholarly journals Identifikasi Potensi Wisata Di Kampung Nelayan Tradisional Desa Lamalera

2018 ◽  
Vol 5 (1) ◽  
pp. 66
Author(s):  
Edel Meriquin Dai Batafor ◽  
I Nyoman Sunarta
Keyword(s):  
Sea Water ◽  
Sandy Beaches ◽  
Tourist Attraction ◽  
Fishing Village ◽  
Qualitative Descriptive ◽  
Tourism Potential ◽  
Traditional Fishing ◽  
The Village

The village of Lamalera has great tourism potential to develope as a tourist attraction. However, it is important to consider some aspects in its development, such asaspect of the environment and the community, so that it will beneficial to the environment and can improve the economy of the community.The problem in this research was the potential of Lamalera, traditional fishing village. Data obtained in this study through observation, interview and documentation. The data were analyzed in qualitative descriptive by describing the potentials of Lamalera, traditional fishing village. The results showed physical and non physical potential of the village. The physical potential of Lamalera is white sandy beaches, crystal clear sea water, undersea view and other beauty of nature; while the non physical potential is in the form of custom ceremonial, traditional dances and religious.   Keywords: Identification, Potential and Tourism

scholarly journals Complete genomes of two extinct New Zealand passerines show responses to climate fluctuations but no evidence for genomic erosion prior to extinction

2019 ◽  
Vol 15 (9) ◽  
pp. 20190491 ◽  
Author(s):  
Nicolas Dussex ◽  
Johanna von Seth ◽  
Michael Knapp ◽  
Olga Kardailsky ◽  
Bruce C. Robertson ◽  
...  
Keyword(s):  
Climate Change ◽  
New Zealand ◽  
Human Impacts ◽  
Oceanic Islands ◽  
Genomic Diversity ◽  
Climate Fluctuations ◽  
Forest Clearing ◽  
Mammalian Predators ◽  
Demographic Trajectories ◽  
Human Climate

Human intervention, pre-human climate change (or a combination of both), as well as genetic effects, contribute to species extinctions. While many species from oceanic islands have gone extinct due to direct human impacts, the effects of pre-human climate change and human settlement on the genomic diversity of insular species and the role that loss of genomic diversity played in their extinctions remains largely unexplored. To address this question, we sequenced whole genomes of two extinct New Zealand passerines, the huia ( Heteralocha acutirostris ) and South Island kōkako ( Callaeas cinereus ). Both species showed similar demographic trajectories throughout the Pleistocene. However, the South Island kōkako continued to decline after the last glaciation, while the huia experienced some recovery. Moreover, there was no indication of inbreeding resulting from recent mating among closely related individuals in either species. This latter result indicates that population fragmentation associated with forest clearing by Maōri may not have been strong enough to lead to an increase in inbreeding and exposure to genomic erosion. While genomic erosion may not have directly contributed to their extinctions, further habitat fragmentation and the introduction of mammalian predators by Europeans may have been an important driver of extinction in huia and South Island kōkako.

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