scholarly journals MARINE VEGETATION FROM A LOCALITY OF THE CONTINENTAL PLATFORM OF LA GUAJIRA (COLOMBIAN CARIBBEAN)

2016 ◽  
Vol 29 ◽  
Author(s):  
Guillermo Díaz Pulido
Keyword(s):  
Continental Shelf ◽  
Thalassia Testudinum ◽  
Leaf Biomass ◽  
Green Macroalgae ◽  
Marine Macrophytes ◽  
Dry Biomass ◽  
The Caribbean

A list of 46 species of marine macrophytes (44 algae and 2 seagrasses) collected between 5 to 36 m depth off Riohacha, on the continental shelf of the peninsula La Guajira (Colombian Caribbean) is presented. 22 species of algae were not previously known from this area. A total of 149 apecies are now registered from the area of La Guajira. Three types of macrophyte asociations were found: (1) dominated by the seagrass Thalassia testudinum with a dry leaf biomass between 27 and 40 gm-2 at 5 m depth. (2) established at -17 m and also dominated by T. testudinum, but with a lower dry leaf biomass (14 gm-2) and a more scattered distribution; green rhizophytic macroalgae (Caulerpa spp.) are quite common. (3) dominated by red and green macroalgae with a total dry biomass of 14 gm-2 at -36 m. 92 % of the species found occurs also in the Santa Marta region, located 160 km far W-SW from the study area. In general, the species found are widely distributed in the Caribbean.

scholarly journals REVISIÓN TAXONÓMICA DEL CORAL PORITES COLONENSIS (SCLERACTINIA: PORITIDAE) EN EL CARIBE COLOMBIANO

2016 ◽  
Vol 37 (2) ◽  
Author(s):  
Dagoberto E. Venera Pontón ◽  
Javier Reyes ◽  
Guillermo Diaz Pulido
Keyword(s):  
Continental Shelf ◽  
Taxonomic Revision ◽  
Caribbean Sea ◽  
South American ◽  
Large Variability ◽  
Porites Astreoides ◽  
Taxonomic Review ◽  
Natural Park ◽  
The Caribbean ◽  
First Time

Porites colonensis is a coral from the Caribbean Sea; colonies are foliaceous, undulated, and plate-like. Polyps are dark brown or red with small bright white or green centers; pali are present in corallites and the septal plan is bisymmetrical, conformed by three fused ventral septa, a dorsal solitary septum, and two pairs of lateral septa at each side of the dorso-ventral axis. P. colonensis is similar and can be confused with the smooth varieties of Porites astreoides and Porites branneri. There are three specimens collected from Colombia and previously identified as P. colonensis: one from Golfo de Urabá (Darién ecoregion), other from Islas del Rosario (Coralline Archipelagos ecoregion), and another from an unspecified locality, in addition to one published observation from the Golfo de Urabá without collected specimens. A recent finding of other specimens in the Tayrona National Natural Park (TNNP, Tayrona ecoregion) and the absence of a rigorous taxonomic revision for all specimens collected from Colombia showed that it was necessary to review the presence and distribution of P. colonensis in the Colombian Caribbean. A taxonomic review was done for all specimens collected from Colombia and previously identified as P. colonensis. Then, the morphologic variability of specimens that were confirmed as P. colonensis was described. Only the specimens from TNNP agreed with the holotype description of P. colonensis, while others agreed with flat varieties of P. astreoides. Thus, the presence of P. colonensis is confirmed for the first time for Colombia, but its presence in other Colombian localities outside Tayrona ecoregion could not be demonstrated. This is the only confirmed record of this species for the South American continental shelf. Furthermore, the skeletal characteristics of Colombian P. colonensis corallites showed large variability, exceeding the ranges previously described for the species.

scholarly journals Testing marine regional-scale hypotheses along the Yucatan continental shelf using soft-bottom macrofauna

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8227 ◽  
Author(s):  
Ivan Hernandez-Avila ◽  
Frank A. Ocaña ◽  
Daniel Pech
Keyword(s):  
Continental Shelf ◽  
Temporal Variation ◽  
Functional Traits ◽  
Regional Scale ◽  
Functional Trait ◽  
Spatial And Temporal Variation ◽  
Soft Bottom ◽  
Community Patterns ◽  
Western Caribbean ◽  
The Caribbean

Different hypotheses related to the regional-scale configuration of the Yucatan Continental Shelf (YCS) between the Gulf of Mexico (GoM) and the Caribbean Sea have been proposed. Hypotheses regarding its regional boundaries include: (i) an ecoregional boundary at Catoche Cape, dividing the Western Caribbean and the Southern GoM ecoregions; and (ii) a boundary within the Southern GoM ecoregion at 89°W, separating the West and Mid-Yucatan areas. We tested the hypothesis of no variation in benthic macrofaunal assemblages between regions delimited by the former boundaries using the species and functional traits of soft-bottom macrofauna. We considered that the depth and temporal environmental dynamics might interact with regional variations, generating complex benthic community patterns. The data were collected over five years (2010–2012, 2015–2016) at 86 stations (N = 1, 017 samples, 10–270 m depth), comprising 1,327 species with 45 combinations of functional traits. The variation in species composition and functional trait assemblages were both consistent with the occurrence of three separate regions in the Yucatan Peninsula (West Yucatan, Mid-Yucatan and Western Caribbean). This regional configuration was consistent with changes in assemblage structure and depth zonation as well as temporal variation. Along with spatial and temporal variation, diversity diminished with depth and different regions exhibited contrasting patterns in this regard. Our results suggest that the spatial and temporal variation of soft-bottom macrofauna at YCS demonstrate the complex organization of a carbonate shelf encompassing different regions, which may represent transitional regions between the Caribbean and the GoM.

scholarly journals Paleo American finds from Venezuela: evidence to discuss the spread of Fell Points and the peopling of Northern South America

2016 ◽  
Vol 29 (45) ◽  
pp. 212 ◽  
Author(s):  
Hugo G. Nami
Keyword(s):  
South America ◽  
Continental Shelf ◽  
Additional Data ◽  
Caribbean Sea ◽  
Hunter Gatherers ◽  
Human Dispersal ◽  
Manufacturing Procedure ◽  
Human Colonization ◽  
The Caribbean ◽  
Northern South America

 “Fishtail” or just “Fell” points represent an excellent marker to know and discuss the existence of colonizers hunter-gatherers living in Central and South America during the end of the Pleistocene at about 11000-10000 14C yr BP. Investigations of Venezuelan fishtail points yielded additional data on their manufacturing procedure to help discuss the human colonization of northern South America. The finds from northern Venezuela on the Caribbean Sea yielded a link arguing for the use of the Atlantic slope and the current continental shelf during human dispersal in South America.“Rabo de peixe” ou somente pontas Fell representam um excelente indicador para conhecer e discutir a existência de colonizadores caçadores-coletores que viveram na América Central e do Sul durante o final do Pleistoceno há aproximadamente 11.000-10.000 14C anos AP. Pesquisas com pontas Rabo de peixe da Venezuela proporcionaram dados adicionais sobre o seu processo de fabricação contribuindo na discussão da colonização humana do norte da América do Sul. As descobertas do norte da Venezuela no Mar do Caribe defendem a utilização da vertente Atlântica e da plataforma continental atual durante a dispersão humana na América do Sul.

scholarly journals SPATIAL AND SEASONAL VARIABILITY OF THALASSIA TESTUDINUM IN NUEVITAS BAY, CUBA

2009 ◽  
Vol 1 ◽  
pp. 9
Author(s):  
Beatriz Martínez-Daranas ◽  
Rubén Cabrera ◽  
Fabián Pina-Amargós
Keyword(s):  
Waste Water ◽  
Root Biomass ◽  
Shoot Density ◽  
Thalassia Testudinum ◽  
Leaf Biomass ◽  
Short Shoot ◽  
Environmental Characteristics ◽  
Daily Production ◽  
Rhizome Biomass ◽  
Sandy Sediments

A study was carried out on biomass, shoot density and leaf production variability in three Thalassia testudinum meadows under different environmental characteristics in Nuevitas Bay, Cuba, in different seasons. The first site has muddy-sandy sediments and it is affected by bottom trawl fishing; the second has sandy sediments and it is affected by waste-water discharges, and the third has sandy-muddy sediments and no human impacts are present. Leaf, rhizome, and root biomass, daily production of leaves, density of short shoots, and length and width of leaves were estimated five times in a year. Seasonal variations were observed, with higher values of leaf and rhizome biomass, short shoot density, and daily production of leaves occurring in spring and summer. Spatial differences seem to be related to the environmental characteristics of each site: Leaf daily production, leaf biomass and leaf length were lower, and root biomass was higher in the site where sediments are impacted by fishing with bottom trawls; short shoot density and rhizome biomass were higher in the nonaffected site. Lower values of root biomass appeared where waste-water discharges occurred.Se realizó un estudio de la variación de la biomasa, la densidad de vástagos y la producción de hojas en tres praderas de Thalassia testudinum con diferentes características ambientales en la bahía de Nuevitas, Cuba, en diferentes épocas del año. El primer sitio tiene sedimentos fango-arenosos y está afectado por pesquería de arrastre; en el segundo, el sedimento es arenoso y se vierten aguas residuales en su cercanía, y el tercero, con sedimentos arenoso-fangosos, no está afectado por impactos antropogénicos. La biomasa de hojas, rizomas y raíces, la producción diaria de hojas, la densidad de vástagos, y el largo y ancho de las hojas fueron estimadas cinco veces en un año. Se observaron variaciones estacionales, con los valores más altos de biomasa de hojas y de rizomas, densidad de vástagos y de la producción diaria de hojas en primavera y verano. Las variaciones espaciales parecen estar relacionadas con las características de cada sitio: La producción diaria de hojas, la biomasa de hojas y su longitud fueron menores, y la biomasa de raíces mayor, donde los sedimentos están impactados por la pesquería con arrastre; la densidad de vástagos y la biomasa de rizomas fueron mayores en el sitio no afectado por ninguna acción antrópica. Los menores valores de la biomasa de raíces aparecieron donde se realiza la descarga de residuales.

scholarly journals Demersal ichthyofauna of the inner continental shelf off Ilhéus, Bahia, Brazil

2009 ◽  
Vol 9 (4) ◽  
pp. 163-168 ◽  
Author(s):  
Leonardo Evangelista Moraes ◽  
Renato de Mei Romero ◽  
Gecely Rodrigues Alves Rocha ◽  
Rodrigo Leão de Moura
Keyword(s):  
Continental Shelf ◽  
Fish Assemblage ◽  
General Structure ◽  
First Record ◽  
Demersal Fish ◽  
South Atlantic ◽  
Range Extension ◽  
The South ◽  
The Caribbean ◽  
Inner Continental Shelf

We present an inventory of demersal fishes from the inner continental shelf off Ilhéus, Bahia, Brazil. Three sites were sampled monthly, between March 2003 and February 2005, with standardized bottom trawls (30 minutes, 16 m depth, 22/16 mm mesh). A total of 7.857 specimens were captured, belonging to three species of Chondrichthyes and 95 species of Actinopterygii (77 genera and 40 families). The occurrence of Ampharius phrygiatus represents a southern range extension for this species, which was previously known only from the narrow coastal stretch between Guyana and Maranhão State (Brazil). The record of Synodus poeyi represents the first record of this species in Brazil and in the South Atlantic, as it was previously recorded only in the Caribbean. The general structure of the demersal fish assemblage is described and commented upon.

scholarly journals Seasonal Distribution of Nutrients and Primary Productivity on the Eastern Continental Shelf of Venezuela as Influenced by the Orinoco River

2016 ◽  
Author(s):  
JAIME BONILLA ◽  
William James Senior
Keyword(s):  
Continental Shelf ◽  
Primary Productivity ◽  
Coastal Upwelling ◽  
Nutrient Status ◽  
Dry Season ◽  
Wet Season ◽  
Orinoco River ◽  
Carbon 14 ◽  
Low Salinity ◽  
The Caribbean

Nitrogenous nutrients, dissolved silicate, and salinity were measured in surface waters and shallowhydrocasts along similar cruise tracks during the spring (dry season) and fall (wet season) of 1988. Bothcruises transected the eastern Caribbean, transited the Gulf of Paria, ran parallel to the Orinoco Deltaand into the main channel of the Orinoco River. Trends in primary productivity were also measuredby daily carbon 14 incubations. In both seasons, samples covered the range from highly oligotrophicand transparent to highly productive and rich in biogenic and abiogenic particulate matter. Most of theOrinoco outflow appears to turn N to NW and remains in shallow waters off Venezuela andsurrounding Trinidad, permitting benthic regeneration of river-borne nutrients. However, the role ofthe Orinoco and associated low-salinity coastal waters in fertilizing large areas of the easternCaribbean basin, as suggested by satellite imagery, can be approximated crudely from the nutrientcomposition at Boca de Dragon, which is representative of the nutrient status of these waters as theyflow into deeper Caribbean waters. Additional nutrients may be supplied to the area primarily fromAmazon-derived water entering the Caribbean Basin further north, with some coastal upwelling alongthe continental shelf in the dry season.

scholarly journals Sea grasses, a new unreported habitat for the heterobranch mollusk Umbraculum umbraculum in the Caribbean region

2020 ◽  
Vol 33 (1) ◽  
pp. 129-133
Author(s):  
Erika García-Bonilla ◽  
Paula González ◽  
Laura Pirateque ◽  
Jüergen Guerrero-Kommritz ◽  
Mónica Puyana ◽  
...  
Keyword(s):  
National Park ◽  
Thalassia Testudinum ◽  
Caribbean Region ◽  
Buffer Area ◽  
The Caribbean

Herein, a new habitat for the heterobranch mollusk Umbraculum is described. One specimen was found on a Thalassia testudinum bed at Taganga Bay at 3 m depth, a buffer area of the Tayrona National Park, Colombian Caribbean. To the best of our knowledge, these mollusks have not been previously reported in this kind of habitat. Seagrasses may provide protection and possibly serve as areas for its reproduction.

scholarly journals ESTRUCTURA DE LAS PRADERAS DE THALASSIA TESTUDINUM EN UN GRADIENTE DE PROFUNDIDAD EN LA GUAJIRA, CARIBE COLOMBIANO

2016 ◽  
Vol 39 (2) ◽  
Author(s):  
Margarita R. Albis Salas ◽  
Diana I. Gómez López ◽  
Guillermo Duque
Keyword(s):  
Organic Matter ◽  
Leaf Area ◽  
Organic Matter Content ◽  
Shoot Density ◽  
Thalassia Testudinum ◽  
Matter Content ◽  
Leaf Biomass ◽  
Total Biomass ◽  
Seagrass Beds ◽  
Substrate Type

The spatial distribution of seagrass beds depends on environmental factors such as light, temperature, salinity, substrate type, and nutrient availability. There is an extensive area of seagrass beds dominated by Thalassia testudinum along the shallow continental shelf of La Guajira, representing more than 80 % of the seagrass beds in Colombia. In order to describe seagrass distribution and its relation to organic matter, substrate type and depth structural variables of T. testudinum were measured at l5 locations placed at one of the following depth ranges: shallow (0-2 m), intermediate (2-4 m), and deep (>4 m). Shoot density was measured with 20 x 20 cm quadrants while shoot samples were collected from 20 x 10 cm sub-quadrants in order to measure leaf biomass, epiphyte weight, grazing and leaf area. Total biomass and sediment core were measured from sediments core samples. High values of shoot density (437.5 m-2), leaf biomass (84.8 g m-2), total biomass (5.9 kg m-2) and leaf area (24.8 cm2), were related with depths less than 3.5 m while at higher depths plants presented lower shoot density (137.5 m2), biomass (7.5 g m-2) and leaf area (4.6 cm2). The epiphyte weight registered high values in deeper seagrass beds (52.5 %) where grazing had lesser impact (53.3 %). Additionally, better devolped seagrass beds were found in areas of organic matter content, fine sediments and protected areas.

scholarly journals NOTES ON THE MARINE ALGAE OF THE INTERNATIONAL BIOSPHERE RESERVE SEAFLOWER, CARIBBEAN COLOMBIA IV: NEW RECORDS OF MACROALGAL EPIPHYTES ON THE SEAGRASS THALASSIA TESTUDINUM

2016 ◽  
Vol 44 (1) ◽  
Author(s):  
Margarita Rosa Albis Salas ◽  
Brigitte Gavio
Keyword(s):  
Marine Algae ◽  
New Records ◽  
Biosphere Reserve ◽  
Thalassia Testudinum ◽  
Morphological Features ◽  
Seagrass Meadows ◽  
The Caribbean ◽  
San Andres

Nine species of macroalgae are newly reported for the Caribbean International Biosphere Reserve Seaflwer. Of these taxa, Neosiphonia sphaerocarpa, Polysiphonia schneideri, Polysiphonia sertularioides, Cladosiphon occidentalis, and Phaeophila dendroides, have been previously reported from Colombian waters, whereas Ulothrix sp., Ulva flxuosa subsp. paradoxa, Chaetomorpha minima, and Cladophora liniformis represent new records for the country. All the algae were found growing epiphytically on Thalassia testudinum in shallow (<1 m) seagrass meadows around San Andrés Island. Their morphological features are discussed.

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