Relation between the type of wave exposure and seagrass losses (Cymodocea nodosa) in the south of Gran Canaria (Canary Islands — Spain)

2014 ◽  
Vol 43 (1) ◽  
Author(s):  
Eduardo Portillo
Keyword(s):  
Canary Islands ◽  
Qualitative Evaluation ◽  
Cymodocea Nodosa ◽  
The South ◽  
Frictional Drag ◽  
Winter Storms ◽  
Gran Canaria ◽  
Seagrass Meadows ◽  
The North ◽  
Storm Waves

AbstractEffects of different types of wave events on Cymodocea nodosa seagrass meadows were observed and investigated by quantitative and qualitative evaluation of material washed ashore a few days after the events. The studied seagrass meadows are located on the south coast of the island of Gran Canaria (Canary Islands — Spain) and they are protected from frequent swells arriving from the North Atlantic. However, sporadic phenomena associated with winter storms occasionally hit this coastline, causing the loss of entire plants (fresh leaves with rhizomes and roots attached). An unusual type of southern swells generated in the South Atlantic also reaches the Islands in spring and summer. A clear relation was observed between the wave events (southern swells and storm waves) and the material cast ashore over the following days, with differences in composition (fresh vs. decaying leaves) depending on the type of event. After southern swells, detached portions of C. nodosa consisted mostly of decaying leaves shed after senescence. These old swells cause frictional drag with moderate oscillations over a wider range at greater depths, removing only decaying leaves from the seagrass meadows and favoring the natural clean-up process.

scholarly journals Spatial variation in the structural parameters of Cymodocea nodosa seagrass meadows in the Canary Islands: a multiscaled approach

2005 ◽  
Vol 48 (2) ◽  
Author(s):  
Carmen Barberá ◽  
Fernando Tuya ◽  
Arturo Boyra ◽  
Pablo Sanchez-Jerez ◽  
Ivan Blanch ◽  
...  
Keyword(s):  
Spatial Variation ◽  
Canary Islands ◽  
Structural Parameters ◽  
Cymodocea Nodosa ◽  
Seagrass Meadows

Seasonal variability of suprabenthic crustaceans associated with Cymodocea nodosa seagrass meadows off Gran Canaria (eastern Atlantic)

2014 ◽  
Vol 88 ◽  
pp. 1-10 ◽  
Author(s):  
A. Herrera ◽  
J.M. Landeira ◽  
F. Tuya ◽  
T. Packard ◽  
F. Espino ◽  
...  
Keyword(s):  
Seasonal Variability ◽  
Cymodocea Nodosa ◽  
Gran Canaria ◽  
Seagrass Meadows

An updated and refined Holocene uplift history of southern Tenerife (Canary Islands) and the possible consequences for future volcanic activity

2015 ◽  
Vol 152 (6) ◽  
pp. 1137-1144
Author(s):  
E. BUCHNER ◽  
J. KRÖCHERT ◽  
M. SCHMIEDER
Keyword(s):  
Canary Islands ◽  
Volcanic Activity ◽  
The South ◽  
The Past ◽  
The North ◽  
Stable Conditions ◽  
Tenerife Island ◽  
History Of ◽  
Uplift History

AbstractVarious uplift markers suggest asymmetrical uplift of Tenerife Island, with stable conditions in the north but significant uplift of up to 45 m in the south over the past ~42 ka. Fossil shells in beach deposits uplifted by 7.5–9 m were 14C-dated at a Holocene age of 2460±35 bp (1σ). This confirms earlier results and documents very young, and probably still ongoing, uplift of southern Tenerife potentially caused by ascending magma. This underlines that southern Tenerife is probably undergoing a further cycle of volcanic activity that started ~95 ka ago.

scholarly journals Spatial variability of planktonic invertebrate larvae in the Canary Islands area

2009 ◽  
Vol 90 (6) ◽  
pp. 1217-1225 ◽  
Author(s):  
J.M. Landeira ◽  
F. Lozano-Soldevilla ◽  
S. Hernández-León ◽  
E.D. Barton
Keyword(s):  
Time Series ◽  
Canary Islands ◽  
Larval Abundance ◽  
The South ◽  
The North ◽  
Larval Distribution ◽  
Eddy Structures ◽  
Anticyclonic Eddies ◽  
Invertebrate Larvae ◽  
Larval Group

In October 1991, invertebrate larvae abundances were analysed to study the influence of the disturbance of the Canary Current flow by the Canary Islands archipelago on the variability of larval distribution. Two transects and two time-series stations located to the north (non-perturbed zone) and the south (perturbed zone) of the Canary Islands were sampled. Oceanographical data showed a highly stratified water column and zonally uniform salinity and temperature seaward of the African upwelling in the non-perturbed zone, while the perturbed zone presented strong turbulence in the form of mesoscale eddies. Invertebrate larval abundances were lower for most taxa studied in the non-perturbed zone and northern time-series station. Significant differences (P < 0.001) of invertebrate larval abundance between the two zones sampled were found. Decapod larvae were the most abundant larval group in both zones. Stations located in eddy structures presented the highest values of larval densities. Specifically, the larvae collected at Station 18, located in the core of an anticyclonic eddy, represented 60±18% of total larvae collected in the south transect. Finally, our results suggest that eddies, mainly anticyclonic eddies, act as a strong larval retention zone south of the islands, and that there is a local northward transport from the Canary Islands.

scholarly journals Boundary Mixing Associated with Tidal and Near-Inertial Internal Waves

2008 ◽  
Vol 38 (6) ◽  
pp. 1238-1252 ◽  
Author(s):  
Jerome Aucan ◽  
Mark Merrifield
Keyword(s):  
Internal Waves ◽  
Internal Tide ◽  
Internal Tides ◽  
The South ◽  
Winter Storms ◽  
Boundary Mixing ◽  
The North ◽  
Thorpe Scale ◽  
Vertical Displacements ◽  
Temperature Inversions

Abstract Moorings deployed on the south (August–November 2002) and north (November 2002–June 2003) flanks of the Kaena Ridge, Hawaii, are used to document the flow variability associated with mixing within 200 m from the boundary, deep along the ridge, as part of the Hawaii Ocean Mixing Experiment (HOME). At both sites, strong temperature inversions are detected with vertical scales of ∼100 m. A Thorpe-scale analysis of the overturns yields a time-averaged dissipation near the bottom at the south site (1.2 × 10−8 W kg−1) that is 10 times higher than the north site (1.9 × 10−9 W kg−1), with both higher than the dissipation at similar depths 30 km from the ridge. On the south flank, observed horizontal currents and vertical displacements are dominated by the semidiurnal internal tide. On the north flank, the semidiurnal tide is less energetic than on the south, with a different vertical structure as tidal amplitudes decrease toward the boundary. These differences are attributed to greater separation from the bottom of downward-propagating internal tides at the north site compared to the south site, resulting in higher mixing at the south site. Near the boundary, near-inertial to diurnal oscillations are more energetic at the north than the south site. This asymmetry is attributed to near-inertial internal waves that are generated north of the ridge by winter storms; the ridge shadows the equatorward-propagating near-inertial internal waves leading to negligible amplitudes on the southern lee side. The near-inertial waves combine with internal tidal motions to create high strain conditions that lead to mixing at the north site.

scholarly journals Airborne dust accumulation and soil development in the North-East sector of Gran Canaria (Canary Islands, Spain)

2007 ◽  
Vol 71 (1) ◽  
pp. 57-81 ◽  
Author(s):  
I. Menéndez ◽  
J.L. Díaz-Hernández ◽  
J. Mangas ◽  
I. Alonso ◽  
P.J. Sánchez-Soto
Keyword(s):  
Canary Islands ◽  
Soil Development ◽  
Gran Canaria ◽  
Airborne Dust ◽  
North East ◽  
The North ◽  
Dust Accumulation

scholarly journals Subtidal soft-bottom macroinvertebrate communities of the Canary Islands. An ecological approach

2012 ◽  
Vol 60 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Oscar Monterroso ◽  
Rodrigo Riera ◽  
Jorge Núñez
Keyword(s):  
Canary Islands ◽  
Ecological Approach ◽  
Macroinvertebrate Communities ◽  
Cymodocea Nodosa ◽  
Soft Bottom ◽  
Gran Canaria ◽  
La Palma ◽  
Diverse Communities ◽  
Soft Bottoms ◽  
Canarian Archipelago

The Canarian archipelago is characterized by a mosaic of soft-bottoms such as Cymodocea nodosa meadows, Caulerpa spp. meadows, mäerl bottoms, sabellid fields and bare sandy seabeds, including various macroinfaunal communities. Vegetated habitats (e.g. Cymodocea and Caulerpa) maintain more diverse communities than the non-vegetated seabeds. The results indicated that Caulerpa meadows and, to a lesser extent, Cymodocea nodosa and sabellid fields are the richest and most diverse ecosystems in the study area. Moreover, biodiversity differences among islands could be detected with maximum values on the eastern islands (Lanzarote and Gran Canaria) and lowest values on the western ones (La Palma).

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