Spatio-temporal variability in a key herbivore, the long-spined black sea urchin (Diadema antillarum, Echinodermata: Echinoidea) in the Canary Islands

2006 ◽  
Vol 86 (4) ◽  
pp. 791-797 ◽  
Author(s):  
F. Tuya ◽  
L. Ortega-Borges ◽  
A.B. Del Rosario-Pinilla ◽  
R.J. Haroun
Keyword(s):  
Sea Urchin ◽  
Black Sea ◽  
Temporal Variability ◽  
Size Structure ◽  
Diadema Antillarum ◽  
Test Diameter ◽  
Risk Of Predation ◽  
The Mean ◽  
Spatio Temporal ◽  
Canarian Archipelago

Spatio-temporal variability in the population structure of long-spined black sea urchin, Diadema antillarum, was investigated at two islands (Gran Canaria and Tenerife) in the Canarian Archipelago over a year. The mean abundance of D. antillarum across all counts was 2.70±0.07 ind m−2 (mean±SE, N=1440), while the mean biomass was 105.76±3.75 g m−2 (mean±SE, N=1440). Abundances and biomasses of D. antillarum differed consistently between vegetated and unvegetated bottoms; however, locations within each habitat at each island fluctuated following different trends. For the overall study, mean densities and biomasses in the barren locations varied between 3.36–6.97 ind m−2 and 93.76–405.13 g m−2, respectively; while mean densities and biomasses in the algal stand locations varied between 0–0.33 ind m−2 and 0 – 7.34 g m−2, respectively. Striking differences existed in the size-structure among locations; however, larger size-classes (test diameter >3.5 cm) were present at all locations, and usually dominated in terms of abundance. The majority of individuals in the algal stands were large-sized, probably as a result of the high abundance of the most palatable food. In contrast, small-sized individuals (test diameter <1.5 cm) only occurred in the barren habitat, suggesting that recruitment of D. antillarum could be favoured by the presence of high densities of congeners, as a way to decrease the risk of predation.

Intensity and spatio-temporal variability of chemical denudation in an arctic-oceanic periglacial drainage basin in northernmost Swedish Lapland

2005 ◽  
Vol 36 (1) ◽  
pp. 21-36 ◽  
Author(s):  
Achim A. Beylich
Keyword(s):  
Spatial Variability ◽  
Snow Cover ◽  
Temporal Variability ◽  
Drainage Basin ◽  
Annual Runoff ◽  
Denudation Rates ◽  
The Mean ◽  
Spatio Temporal ◽  
Alpine Environments ◽  
Arctic Summer

The intensity and spatio-temporal variability of chemical denudation was analyzed in the Latnjavagge drainage basin (9 km2; 950–1440 m a.s.l.; 68°20′N, 18°30′E), an arctic–oceanic periglacial environment in northernmost Swedish Lapland. Data on daily runoff and solute concentrations at different test sites within the selected representative drainage basin were collected during the entire arctic summer seasons of 2000, 2001, 2002 and 2003. The mean annual chemical denudation net rate for the Latnjavagge drainage basin is 5.4 t/km2 yr. Most of the annual runoff occurs when the ground is still frozen. The rate in Latnjavagge is much lower than chemical denudation rates reported for Kärkevagge (Swedish Lapland) situated close to Latnjavagge, but at a similar level to a number of other subarctic, arctic and alpine environments. Chemical denudation shows a spatio-temporal variability within the drainage basin, which is mainly caused by a spatio-temporal variability of snow cover and ground frost and a spatial variability of regolith thicknesses within Latnjavagge.

scholarly journals The association of test diameter and gonad weight with some toxic trace metals level in black sea urchin (Stomopneustes variolaris)

2018 ◽  
Vol 7 (1) ◽  
Author(s):  
H. K. S. De Zoysa ◽  
B. K. K. K. Jinadasa ◽  
E. M. R. K. B. Edirisinghe ◽  
G. D. T. M. Jayasinghe
Keyword(s):  
Trace Metals ◽  
Sea Urchin ◽  
Black Sea ◽  
Gonad Weight ◽  
Test Diameter ◽  
Toxic Trace Metals

scholarly journals ESTADO ACTUAL DE LAS POBLACIONES DEL ERIZO NEGRO DIADEMA ANTILLARUM PHILIPPI (ECHINOIDEA: DIADEMATIDAE) EN EL PARQUE NACIONAL NATURAL TAYRONA Y PLAYA BLANCA, SANTA MARTA, CARIBE COLOMBIANO

2016 ◽  
Vol 40 (2) ◽  
Author(s):  
Fanny Tatiana González Gaviria ◽  
Rocío García Urueña
Keyword(s):  
Sea Urchin ◽  
Size Structure ◽  
Coral Community ◽  
The Black Sea ◽  
Diadema Antillarum ◽  
Slow Recovery ◽  
Mass Mortality Event ◽  
Natural Park ◽  
The Status ◽  
Line Transects

Diadema antillarum experienced a mass mortality event between 1983-1984 that dropped its densities about 93 %, a phenomenon that led to a macroalgae dominance in most reefs. This study was performed in Tayrona National Natural Park (PNNT) and Playa Blanca (Bahía de Gaira) to determine the status of the black sea urchin populations. At each site, five 10 m line transects were located perpendicular to each other and the density was estimated by 1 m2 squares; coral community composition and roughness was recorded by video. Size structure was calculated by collecting between 31 and 52 individuals and measuring the diameter and height of the test. The highest mean density was found in Nenguange (1.16 ind/m2) and lowest in Chengue (0.04 ind/m2), both located in the PNNT. Mean test diameter was between 58.84 and 80.60 mm. No relation was found between the main reef components (corals, macroalgae or dead coral) and the sea urchin densities, neither between diversity and uniformity and sea urchin densities. Our results show that the density is in the range of current abundance reported in other Caribbean regions, indicating a slow recovery of populations.

scholarly journals Simulation modelling of wind-induced sea level fluctuations at the ports of the Odesa Region in the North-Western part of the Black Sea

2019 ◽  
pp. 109-120
Author(s):  
Yu. S. Tuchkovenko
Keyword(s):  
Sea Level ◽  
Black Sea ◽  
Hydrodynamic Model ◽  
Temporal Variability ◽  
The Black Sea ◽  
Sea Level Fluctuations ◽  
The North ◽  
Allowable Error ◽  
Spatio Temporal ◽  
North Western

The paper is devoted to discussion of the prospects of simplified 2D hydrodynamic model use aimed at forecasting the wind-induced sea level fluctuations within the area of sea ports (Chornomorsk, Odesa and Yuzhnyi) of the Odesa Region in the North-Western part of the Black Sea. Spatio-temporal variability of wind conditions at the sea-atmosphere division is specified based on the data of the global numerical weather prediction model of the Global Forecast System (GFS). The research includes the description of the mathematical structure of the hydrodynamic model and the results of its adaptation to the conditions of the simulated sea area. It presents the results of model verification in the version which implies adoption of wind data from the archives of GFS-analysis and GFS-forecasts for 2010, 2016 and 2017. The verification was performed by comparing wind-induced denivellations of the sea level at the ports of Chornomorsk, Odesa and Yuzhnyi calculated over the course of modelling and those established on the basis of observational data (with the discreteness of 6 hours). A quantitative assessment of the calculation accuracy was performed for the cases where, according to the observational data, level denivellations exceeded the value of the standard deviation for the entire series. New series of the observed and calculated model-based significant wind-induced denivellations of sea level were formed for each of the ports from the sets of samples that met this condition. Using  these series estimates of the mean square error of the calculations, allowable error of calculations, correlation coefficient between the actual and calculated values of the level denivellations, the probability of the calculation method under the allowable error were obtained. It was established that in the case of use of the data from wind GFS-analysis (with spatial resolution of 0.5° both latitudinally and longitudinally) over the course of modelling the probability of calculation of significant sea level denivellation constitutes 84-85%, and in case of using the data from the GFS-archive of wind forecasts (with spatial resolution of 0.25°) – 88-91%. This allowed making a conclusion that the model has good prospects of use for operational forecast of the sea level fluctuations caused by storm wind in the version implying assimilation of the predicted information on the spatio-temporal variability of wind conditions obtained by means of the GFS global weather forecast model.

scholarly journals Independent components of spatial-temporal structure of chlorophyll a patterns in the upper layer of the north-western shelf of the Black Sea

One Ecosystem ◽  
2021 ◽  
Vol 6 ◽  
Author(s):  
Natalya Kyrylenko ◽  
Vladyslav Evstigneev
Keyword(s):  
Black Sea ◽  
Temporal Variability ◽  
Temporal Structure ◽  
The Black Sea ◽  
Phytoplankton Succession ◽  
Independent Components ◽  
The North ◽  
Component Decomposition ◽  
Spatio Temporal ◽  
North Western

In the present study, the results of independent component decomposition of satellite-derived chlorophyll a (Chla) patterns for the north-western part of the Black Sea are presented. The study has been carried out on the basis of the DINEOF-reconstructed dataset of 8-day average log-transformed Chla (alChla) patterns for 1997-2016. The alChla patterns were decomposed into six independent components of its spatio-temporal variability in the north-western shelf of the Black Sea. The independent components reflect the spatial distribution of alChla anomalies which are likely to be formed under the influence of sea circulation factors driven by wind. The paper presents the results of the analysis of the intra-annual variability of independent components. The interpretation of the patterns of intra-annual independent components variability is given, taking into account the seasonal variability of the wind factor, the flow of the Danube, the Dnieper and Southern Bug rivers and the fact of modulation of independent components dynamics by seasonal phytoplankton succession.

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