scholarly journals Coverage Increases of Porites astreoides in Grenada Determined by Shifts in Size-Frequency Distribution

Diversity ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 288
Author(s):  
Ryan G. Eagleson ◽  
John S. Lumsden ◽  
Lorenzo Álvarez-Filip ◽  
Christophe M. Herbinger ◽  
Ryan A. Horricks

Despite coral community collapse, the mustard hill coral (Porites astreoides) is a species currently experiencing success throughout the Caribbean. The inshore reefs of Grenada were selected to study the influence of benthic factors on the abundance, size, and coverage of P. astreoides colonies. Surveys of reef communities along established 30 m transects were conducted at eight sites in 2014 and 2017 using a 0.5 m² quadrat. Coral Point Count was used to annotate the images, estimating the coverage of scleractinian corals, sponges, algae, and benthic substrates. Coverage, size, and abundance of P. astreoides colonies were quantified using the area measurement tool in ImageJ standardized against the quadrats. There were significant differences in benthic community assemblages between islands, selected sites, and between years. From 2014 to 2017 there was a significant decrease in the mean abundance of P. astreoides colonies and significant increases in mean colony size and coverage. The presence of P. astreoides colonies was significantly correlated with: rubble (−), sand (−); pavement (+); macroalgae (−); coralline algae (+); sponges (varying response); gorgonians (−); massive corals (+); and branching corals (−). P. astreoides follows similar recruitment patterns as other scleractinian corals. Observed changes in P. astreoides populations appear to indicate a recovery event following a disturbance, potentially tropical storm Chantal in 2013.

2011 ◽  
Vol 3 ◽  
pp. 77 ◽  
Author(s):  
Leslie Hernández Fernández ◽  
Mayrene Guimarais Bermejo ◽  
Rodolfo Arias Barreto ◽  
Lídice Clero Alonso

En los años 2001 y 2005, se estudió la composición de las comunidades de octocorales y corales pétreos en el archipiélago de los Jardines de la Reina. Se analizó, en la comunidad de corales pétreos, la incidencia del blanqueamiento ocurrido en el 2005 en el Caribe. Para ello se establecieron doce estaciones de muestreo (siete en el arrecife frontal somero y cinco en el arrecife de cresta), en cada una de estas se estimó la densidad mediante el marco cuadrado de 1 m de lado. En el arrecife frontal somero se identificaron un total de 62 especies (26 de octocorales y 36 de corales), siendo las más abundantes: Pseudopterogorgia americana (2.4 colonias/m2), Eunicea flexuosa (1.1 colonias/m2), Siderastrea siderea (5.0 colonias/m2) y Agaricia agaricites (4.0 colonias/m2). En el arrecife de cresta se identificaron un total de 31 especies (13 de octocorales y 18 de corales), predominando: Briareum asbestinum (1.3 colonias/m2), Porites astreoides (2.5 colonias/m2) y Millepora complanata (1.0 colonias/m2). Las especies más sensibles al blanqueamiento fueron: A. agaricites , Millepora spp. y Montastraea annularis. En sentido general, dicho suceso tuvo una incidencia pobre sobre los corales pétreos. Es menester la ejecución de monitoreos al permitir ajustar los planes de manejo en función de los cambios que puedan ocurrir en la estructura de las comunidades bentónicas.ABSTRACT Octocoral and stony coral communities in the Jardines de la Reina archipelago (Cuba) were studied in 2001 and again in 2005. The incidence of the 2005 bleaching event in the Caribbean was analyzed in the stony coral community. Twelve sampling stations were established: seven in the shallow forereef and five in reef crests, with one square meter quadrants to estimate density. A total of 62 species (26 octocorals and 36 stony corals) were identified in the shallow forereef, including Pseudopterogorgia americana (2.4 colonies/m2), Eunicea flexuosa (1.1 colonies/m2), Siderastrea siderea (5.0 colonies/m2) and Agaricia agaricites (4.0 colonies/m2). In the reef crest, 31 species were identified (13 octocorals and 18 stony corals), with Briareum asbestinum (1.3 colonies/m2), Porites astreoides (2.5 colonies/m2) and Millepora complanata (1.0 colonies/m2) being the most abundant. The most sensitive species to bleaching were: A. agaricites, Millepora spp. and Montastraea annulariS. In general, this event showed a poor incidence with stony corals. Constant monitoring is necessary to adjust the management plan to the changes that may occur in the structure of the benthic communities.


Coral Reefs ◽  
2021 ◽  
Author(s):  
Florentine Riquet ◽  
Aurélien Japaud ◽  
Flávia L. D. Nunes ◽  
Xaymara M. Serrano ◽  
Andrew C. Baker ◽  
...  

2011 ◽  
Vol 101 (1-2) ◽  
pp. 5-14 ◽  
Author(s):  
Douglas F Peiró ◽  
Fernando L Mantelatto

The Pinnotheridae family is one of the most diverse and complex groups of brachyuran crabs, many of them symbionts of a wide variety of invertebrates. The present study describes the population dynamics of the pea crab Austinixa aidae (Righi, 1967), a symbiont associated with the burrows of the ghost shrimp Callichirus major (Say, 1818). Individuals (n = 588) were collected bimonthly from May, 2005 to September, 2006 along a sandy beach in the southwestern Atlantic, state of São Paulo, Brazil. Our data indicated that the population demography of A. aidae was characterized by a bimodal size-frequency distribution (between 2.0 and 4.0 mm and between 8.0 and 9.0 mm CW) that remained similar throughout the study period. Sex ratio does not differ significantly from 1:1 (p > 0.05), which confirms the pattern observed in other symbiontic pinnotherids. Density values (1.72 ± 1.34 ind. • ap.-1) are in agreement with those found for other species of the genus. The mean symbiosis incidence (75.6%) was one of the highest among species of the Pinnotheridae family, but it was the lowest among the three studied species of the genus. Recruitment pattern was annual, beginning in May and peaking in July, in both years, after the peak of ovigerous females in the population (from March to May). Our findings describe ecological and biological aspects of A. aidae similar to those of other species of this genus, even from different geographic localities.


Author(s):  
Dagoberto E. Venera Pontón ◽  
Javier Reyes ◽  
Guillermo Diaz Pulido

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.


2017 ◽  
Vol 32 (1) ◽  
pp. 11
Author(s):  
IVONNE LUNA ORTEGA ◽  
VICENCIO DE LA CRUZ FRANCISCO

Las macroalgas son abundantes en el arrecife Oro Verde, Veracruz pero, hasta ahora, se desconocía su riqueza taxonómica, y se presume que presentan asentamientos en los corales escleractinios hermatípicos. Por ello el presente trabajo investigó qué especies de corales presentaron colonizaciones algales; además, se determinó la composición taxonómica y la similitud de los ensambles de macroalgas entre las especies de corales escleractinios. Se establecieron diez puntos de muestreo de manera sistemática en el arrecife; en cada lugar de estudio se colocó un transecto de banda de 50 x 2 m para localizar y recolectar macroalgas en superficies muertas de corales escleractinios. La frecuencia de aparición de las algas se estimó con base en el total de corales estudiados, así como para cada especie coral. Para explicar similitudes y diferencias significativas de la composición de ensamblajes macroalgales entre especies de corales se aplicaron análisis de similitud y ordenación. Los corales escleractinios con ensambles de algas fueron Siderastrea siderea, Montastraea cavernosa, Pseudodiploria strigosa, Colpophylia natans, Stephanocoenia intersepta, Porites astreoides, Orbicella annularis, Orbicella faveolata. De un total de 100 colonias coralinas revisadas se determinaron 32 especies de macroalgas, las cuales están representadas en tres divisiones, 10 órdenes y 15 familias. Las macroalgas corticadas, foliosas corticadas y filamentosas fueron las más representadas en especies. Las algas de mayor frecuencia sobre los corales masivos fueron Laurencia obtusa, Amphiroa rigida y Caulerpa chemnitzia. Los corales masivos con mayor número de registros de algas fueron S. siderea (9 especies), M. cavernosa (19) y P. strigosa (17). Los ensambles algales en los corales masivos presentaron baja similitud, sin embargo no se detectaron grupos significativamente disimiles. Solamente S. siderea y M. cavernosa son ligeramente parecidos en la composición ficológica. Los resultados sugieren que los corales masivos del arrecife Oro Verde son vulnerables a la colonización de algas, pero es necesario indagar qué condiciones preceden al asentamiento algal.Macroalgal assemblages on dead surfaces of scleractinian corals (Anthozoa: Scleractinia) in the Oro Verde reef, Veracruz, MexicoBenthic macroalgae are abundant in the Oro Verde reef but their taxonomic richness was hitherto unknown and it is presumed to present settlements on the massive corals. For this reason, the present work investigated which species of massive corals show algal colonization. Also, their taxonomic composition was determined, and the similarity of the algal assemblages between species of scleractinian corals was measured. Ten sampling points were systematically established in the reef, where a transect band of 50 x 2 m at each site was placed to locate and collect algae fron the dead surfaces of scleractinian corals. The frequency of occurrence of algae species was estimated based on the total number of coral species studied, as well as on each coral species. Similarity and ordination analysis were applied in order to explain similarities and significant differences of the phycological composition among the coral species. Scleractinian corals with algal assemblages were: Siderastrea siderea, Montastraea cavernosa, Pseudodiploria strigosa, Colpophylia natans, Stephanocoenia intersepta, Porites astreoides, Orbicella annularis, Orbicella faveolata. Thirty-two species of algae were identified from a total of 100 revised coral colonies which are represented in 3 divisions, 10 orders and 15 families. The corticated, foliose corticated and filamentous macroalgae were the most represented species. The most frequent algae on massive corals were Laurencia obtusa, Amphiroa rigida and Caulerpa chemnitzia. Massive corals with higher algal records were S. siderea (9 species), M. cavernosa (19 species) and P. strigosa (17 species). The algal assemblages on the massive corals presented low similarity. However, no significant dissimilar groups were detected. Only S. siderea and M. cavernosa are relatively similar in phycological composition. The results suggest that the massive corals of the Oro Verde reef are vulnerable to the colonization of algae, but it is necessary to investigate the conditions preceding algal settlement.


1970 ◽  
Vol 14 ◽  
pp. 35-42 ◽  
Author(s):  
Danda Pani Adhikari

A 17.63 m long bore-hole core extracted from the deepest part of Lake Yamanaka, one of the Fuji-five Lakes at the northeasternfoot of Mount Fuji, central Japan, composed of sediment with intercalations of scoria fallout deposits. The sediment of the upper11.4 m was investigated for grain-size distribution by using a laser diffraction particle size analyser. The mean grain-size profileshowed various degrees of fluctuations, both short-and long-terms, and the size-frequency distribution revealed unimodal-trimodalmixing of sediments. Changes in lake size and water depth appear to be the main factors affecting the variability in the grain-sizedistribution and properties. The lake level appears low during 7000–5000 cal BP and 2800–1150 cal BP and relatively high during5000–2800 cal BP and 1150 cal BP– present.DOI: http://dx.doi.org/10.3126/bdg.v14i0.5437Bulletin of the Department of Geology Vol.14 2011, pp.35-42 


2017 ◽  
Vol 11 (2) ◽  
pp. 48-57
Author(s):  
Francisco Javier Sot ◽  
Alex Edgardo Me ◽  
Koralis Reyes-Mald ◽  
Alberto Miguel Sab

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Bryan Wilson ◽  
Chen-Ming Fan ◽  
Peter J. Edmunds

AbstractSeveral species of crustose coralline algae (CCA) and their associated microbial biofilms play important roles in determining the settlement location of scleractinian corals on tropical reefs. In recent decades, peyssonnelid algal crusts (PAC) have become spatial dominants across large areas of shallow Caribbean reefs, where they appear to deter the recruitment of scleractinians. Our genetic investigations of PAC in St. John, US Virgin Islands, amplifying the large-subunit ribosomal RNA and psbA protein D1 marker genes, revealed them to be identical to Ramicrusta textilis previously reported overgrowing corals in Jamaica. Specimens of PAC sampled from the Honduras were likewise identical, confirming that this crustose alga inhabits the easternmost and westernmost regions of the Caribbean. We also analysed 16S rDNA tag amplicon libraries of the biofilms associated with PAC and sympatric CCA, which is favoured for coral settlement. Our results show that the microbial communities on PAC (vs. CCA) are characterized by significantly lower numbers of the epibiotic bacterial genus Pseudoalteromonas, which facilitates the recruitment and settlement of marine invertebrates. From these data, we infer that PAC are therefore unlikely to be attractive as settlement sites for coral larvae. Given the significant ecological change anticipated on these reefs due to increasing cover of PAC, there is an urgent need to further investigate competitive interactions between PAC and scleractinian corals, and elucidate the role of PAC and their associated microbiomes in accentuating phase shifts from coral to algae on tropical reefs.


2019 ◽  
Vol 33 (04) ◽  
pp. 357-364
Author(s):  
Kelly M. Rogers ◽  
Daniel C. Berman ◽  
Justin W. Griffin ◽  
Kevin F. Bonner

AbstractThe purpose of this study was to assess potential gender differences in size of the lateral and medial trochlea of the male and female knee as well as the variation within gender of potential osteochondral autograft transfer (OAT) donor site area. Two hundred and twelve skeletally mature patients, 106 males and 106 females, who underwent a 3T magnetic resonance imaging of the knee for a variety of indications were utilized for analysis. Exclusion criteria included degenerative arthritis, trochlear dysplasia, and poor image quality. Medial and lateral femoral trochlear cartilage width was obtained using a linear radiologic measurement tool. Widths were measured from a reproducible anatomic location representing the maximal trochlear dimension in a region where donor plugs are commonly harvested. Trochlear width was also plotted as a function of patient height. Statistical analysis was performed using a two-sample t-test. The mean and standard deviation of the lateral trochlear cartilage width (mm) for males and females were 23.38 +/− 2.14 and 20.44 +/− 2.16, respectively (p < 0.00001). The mean and standard deviation of the medial trochlear cartilage width (mm) for males and females were 14.16 +/− 2.17 and 11.78 +/− 2.03, respectively (p < 0.00001). The overall range in trochlear width for both the lateral and medial sides was 22.22 and 19.73 mm for males and females, respectively. A graft measuring 10 mm could represent as little as 34% of the lateral trochlea in males versus as much as 65% in females. Our results indicate that donor OAT plug diameter relative to available trochlear cartilage width will vary significantly both between genders and individual patients. Trochlear width variability and its potential implications on donor site morbidity may be an important consideration when contemplating osteochondral plug harvest for OAT or other indications. The level of evidence is IV.


2006 ◽  
Vol 3 (1) ◽  
pp. 16-19 ◽  
Author(s):  
D Ryan Norris ◽  
Peter P Marra ◽  
T Kurt Kyser ◽  
Laurene M Ratcliffe ◽  
Robert Montgomerie

Understanding the causes of variation in feather colour in free-living migratory birds has been challenging owing to our inability to track individuals during the moulting period when colours are acquired. Using stable-hydrogen isotopes to estimate moulting locality, we show that the carotenoid-based yellow–orange colour of American redstart ( Setophaga ruticilla ) tail feathers sampled on the wintering grounds in Central America and the Caribbean is related to the location where feathers were grown the previous season across North America. Males that moulted at southerly latitudes were more likely to grow yellowish feathers compared with males that moulted more orange–red feathers further north. Independent samples obtained on both the breeding and the wintering grounds showed that red chroma—an index of carotenoid content—was not related to the mean daily feather growth rate, suggesting that condition during moult did not influence feather colour. Thus, our results support the hypothesis that feather colour is influenced by ecological conditions at the locations where the birds moulted. We suggest that these colour signals may be influenced by geographical variation in diet related to the availability of carotenoids.


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