Search results for "oceanic"

Seasonal dynamics of Posidonia oceanica beach-cast wracks in a Sicilian beach: an overlooked system for carbon dynamics

2019

Seagrass detritus accumulates along the coasts forming beach-cast wracks. Being subject to environmental gradients and hydrodynamism, the size and composition of beach-cast wracks may vary in space and time. Also the composition may vary depending on both proximities to and productivity of the adjacent seagrass meadows. Despite their dynamic nature, seagrass beach-casts provide important ecosystem services, by contributing to the nutrient and carbon flow between marine and terrestrial systems, supporting beach biodiversity and trophic webs and protecting the coastline from erosion. However, the knowledge about beach-cast dynamics, ecological role and functions is still fragmented and deserv…

The use of very high resolution images for the estimation of Posidonia oceanica beach-cast morphology

2019

Posidonia oceanica is an endemic Mediterranean seagrass that forms wide and dense meadows from the surface to depths of about 40 m. During fall and winter, due to aging and storms, leaves and rhizomes break away from the seagrass meadows and accumulate on the shores (from a few centimeters in the water to several meters inshore) forming conspicuous beach-casts of P. oceanica detritus. These structures have received increasing attention in the last decade for the potential ecosystem services they provide in protecting the coast from erosion, linking marine and terrestrial food chains and contributing to carbon and nutrients fluxes. However, seagrass beach-cast morphology is not easy to estim…

Biodegradable anchor modular system for transplanting Posidonia oceanica cuttings

2014

Estimation of the volume of Posidonia oceanica detritus accumulations along Sicilian coasts by using very high resolution images

2019

Posidonia oceanica meadows are among the most important marine coastal ecosystems in the Mediterranean Sea due to several roles they are able to play. They, in fact, support high levels of primary production, enhance sedimentation of suspended particles through their canopies, prevent resuspension of marine sediments by means of roots and rhizomes and counteract coast erosion. Part of the primary production of this seagrass is not transferred to herbivores either immediately to detritus pathway but it can accumulate on the shore in form of banquette, typical structures exerting a significant role in protection of beaches from erosion. To accurately measure the extension, morphology, volume …

Quali-quantitative assessment of Posidonia oceanica detritus accumulations in pocket-beaches with different productivity levels of nearshore seagrass…

2019

Posidonia oceanica detritus accumulates in late summer-autumn along the coasts forming beach-cast seagrass wracks known as banquette. Although seagrass wracks are highly variable at both spatial and temporal scales, they have an important ecological role as they protect the coast from erosion, support beach biodiversity and trophic webs and supply nutrients to dune vegetation. Previous studies have focused mainly on the beach-cast morphological characterization and variability, as well as on associated biotic communities. However, few studies have focused on the quali-quantitative assessment of seagrass wracks. The aim of this study was to assess the spatial variability of the P.oceanica be…

Ecological role and exploitation of Posidonia oceanica in the Mediterranean area

2018

The paleoendemic seagrass Posidonia oceanica (L.) Delile (Posidoniaceae) represents a key species of the most important and productive ecosystem in subtidal habitats of the Mediterranean Sea. This species is the most common seagrass in Sicily where it forms dense and extensive beds, which are characterized by high coverage and primary production values, along the Western coasts. According to phenological processes, the beaching of P. oceanica residues (banquette) represents a great environmental, economic, social and, hygienic problem, conflicting with a number of activities (tourism, bathing establishments, etc.). Even though seagrasses play a fundamental ecological role in limiting coasta…

PRELIMINARY INVESTIGATIONS ON THE FLORA OF THE PERMANENT BANQUETTES IN WESTERN SICILY

2016

The banquettes, landed clusters of dead leaves of Posidonia oceanica (L.) Delile, represent a deposited biomass from sea to land that protects the shoreline from wind and sea erosion as well as constitutes a reserve of nutrients and organic matter for sea prairies. These wracks can become a potential biodiversity hotspot as indicated by a recent investigation on invertebrates that has shown high levels of consumption of detritus (1). This biodiversity, greater than that found in coastal areas without such accumulations, can be explained by the margin effect between the marine and the terrestrial environment. The banquette can therefore be considered an ecotone (2, 3) where communities of su…

Mapping Posidonia oceanica lower limit combining high resolution instruments (SSS and MBS)

2014

The use of very high-resolution images for mapping of Posidonia oceanica reef

2020

Posidonia oceanica is an endemic Mediterranean seagrass that forms wide and dense meadows from the surface up to about 40 m depth. P. oceanica can develop on matte, a typical terraced structure built up by itself, consisting of intertwined rhizomes, roots and sediment, which may allow shoots to reach the sea surface, where may form typical reefs (récif barrière) considered “natural monuments”. These structures have received increasing attention for the potential ecosystem services they provide in protecting the coasts from erosion, forming new habitats (coastal lagoons) and contributing to carbon sink. P. oceanica reefs are particularly exposed to the expected increase in temperature and to…

Shoot age as a confounding factor on detecting the effect of human-induced disturbance on Posidonia oceanica growth performance

2007

Abstract The response of orthotropic rhizome elongation and primary production of Posidonia oceanica to anthropogenic perturbations and potential confounding effects of shoot age were assessed using a Linear Multilevel Model (LMM). This model examined the confounding effect of age by comparing the estimates of impact and variance components obtained by excluding and including Age as an explanatory variable. Age had a negative effect on rhizome elongation and primary production with an annual decrease of 0.6 mm y − 1 and 7 mg dw y − 1 respectively. According to the LMM when age effect was omitted, the differences between disturbed and control locations in rhizome elongation and primary produ…