Does depth and sedimentation interact with sea urchings to affect algal assemblage patterns on eastern atlantic reefs?

[EN]A range of factors may affect the composition and abundance of macroalgae on subtidal rocky reefs. We experimentally determined the interactive effect of the occurrence of the long-spine sea urchin, Diadema antillarum, depth and sedimentation levels on macroalgal assemblage structure on eastern Atlantic rocky reefs. Specifically, we manipulated sea urchin densities (removal of all individuals vs. untouched controls at natural densities) on rocky reefs devoid of erect vegetation, and predicted (1) that removal of sea urchins would differently affect macroalgal assemblage structure between deep (16-18 m) and shallow (8-9 m) reef strata, and that (2) the effect of sea urchin removal on macroalgae would be altered under different scenarios of sedimentation (ambient vs. enhanced). Experimental circular plots (2 m in diameter) were set up at 3 locations at Gran Canaria (Canarian Archipelago), and were maintained and monitored every 4 wk for 1 y. At the end of the experimental period, the structure of the algal assemblages differed between urchin treatments and depth strata, with a larger cover of turf and bushlike algae where urchins were removed and at the shallow reef stratum. More important, differences in algal assemblage structure between urchin treatments were irrespective of sedimentation levels, but shifted from the shallow to the deep stratum. This interactive effect was, in turn, observed for bushlike algae, as a result of a larger magnitude of response (i.e., larger cover) in the shallow stratum relative to the deep stratum, but was not detected for either turf or crustose coralline algae. These results highlight the importance of sorne physical conditions (here, differences in depth) to interact with biotic processes (here, urchin abundance) to create patterns in the organization of subtidal and benthic assemblages

Carbon flux, nutrient retention efficiency and the curvature of respiration depth-profiles in the ocean water column

Trabajo realizado por: Packard, T. T., Osma, N., Fernández Urruzola, I., Gómez, M

Temporal patterns of the seagrass "Cymodocea nodosa" and depth-related patterns of the green algae "Caulerpa prolifera" in the Canarian Archipelago

Máster Oficial en Gestión Costera

People counting with re-identification using depth cameras

[EN]Low cost real-time depth cameras offer new sensors for a wide field of applications apart from the gaming world. Other active research scenarios as for example surveillance, can take ad- vantage of the capabilities offered by this kind of sensors that integrate depth and visual information. In this paper, we present a system that operates in a novel application context for these devices, in troublesome scenarios where illumination conditions can suffer sudden changes. We focus on the people counting problem with re-identification and trajectory analysis.

Orígenes de la cabra paleo-canaria de villaverde (Fuerteventura)

[EN] After comparing the features of the group of goats from Villaverde ( osseous remains from the beginning of our era), -La Palma (recently extinct), and - Desertas (descendants of the anciet Canarian goat ), all of them cosidered to be of the same breed, with those of the neolithic and protohistoric goats from North Africa, greater affinity is found with the mamber goat of the predinastic Egypt and the Ancient Egyptian Empire, represented in King Ranusir's tomb (V Dinasty) 4.500 years ago, and affinity is also found with the neolithic goat painted in Amguid (Central Sahara) and the modern Sahel goats, although the paleo - Canarian goat has its own features.

La cabra paleo-canaria de Villaverde (Fuerteventura)

[ES] Miles de fragmentos óseos pertenecientes a medio millar de cabras domésticas de los pobladores de Fuerteventura durante el primer milenio de nuestra Era han sido extraídos en las excavaciones arqueológicas realizadas en la Cueva de Villaverde. Algunas de las piezas óseas estaban más completas y han permitido atisbar el aspecto de esa casta paleo-canaria que no ha subsistido en las islas, salvo quizás hasta hace poco en la Caldera de Taburiente en La Palma, puesto que ya en los siglos XVI y XVII se cruzó numerosísimas veces con ejemplares de muy diversos lugares de Europa para obtener la gran productividad lechera que caracteriza hoy a las cabras de Fuerteventura.

Orígenes de la oveja paleo-canaria de Villaverde (Fuerteventura)

[ES] El hallazgo de restos óseos de oveja durante las excavaciones arqueológicas realizadas en la Cueva de Villaverde en Fuerteventura ha permitido la reconstrucción parcial de su esqueleto, la comparación biométrica con ovicaprinos de otras culturas prehistóricas y evidenciar algunos de sus rasgos. La talla es grande, entre 70 y 80 cm. de cruz, las patas largas (longipes), al menos las hembras carecen de cuernos (acerata) y el perfil facial es recto. Otra información, antiguos escritos como los de ABREU GALINDO en 1602 y ESCUDERO en 1639, da a conocer la presencia en Canarias de una raza de carneros y ovejas "que no tienen lana, sino pelo liso como cabras" "rasas sin cuernos ni lanas" "cueros muy gruesos" "cuero peloso de carnero" "al cuero llamaban harhuy" "ovejas gordas y de mucha grasa" "ovejas no como las de España" (MEC0,1992).

Restos óseos de la oveja paleo-canaria de Villaverde (Fuerteventura)

[ES] Entre los materiales extraidos en las excavaciones arqueológicas de la Cueva de Villa verde en Fuerteventura han aparecido restos óseos fragmentados pertenecientes a oveja. La Cueva fue habitada por antiguos pobladores de la isla entre el año 200 y el año 1.000 de nuestra era (HERNANDEZ et. al., 1988).