scholarly journals Assessment of microbial plankton diversity as an ecological indicator in the NW Mediterranean coast

2020 ◽  
Vol 160 ◽  
pp. 111691
Author(s):  
Isabel Ferrera ◽  
Albert Reñé ◽  
David Funosas ◽  
Jordi Camp ◽  
Ramon Massana ◽  
...  
2020 ◽  
Vol 8 (11) ◽  
pp. 911
Author(s):  
Francesca Iuculano ◽  
Carlos M. Duarte ◽  
Jaime Otero ◽  
Xosé Antón Álvarez-Salgado ◽  
Susana Agustí

Posidonia oceanica is a well-recognized source of dissolved organic matter (DOM) derived from exudation and leaching of seagrass leaves, but little is known about its impact on the chromophoric fraction of DOM (CDOM). In this study, we monitored for two years the optical properties of CDOM in two contrasting sites in the Mallorca Coast (Balearic Islands). One site was a rocky shore free of seagrass meadows, and the second site was characterized by the accumulation of non-living seagrass material in the form of banquettes. On average, the integrated color over the 250–600 nm range was almost 6-fold higher in the beach compared with the rocky shore. Furthermore, the shapes of the CDOM spectra in the two sites were also different. A short incubation experiment suggested that the spectral differences were due to leaching from P. oceanica leaf decomposition. Furthermore, occasionally the spectra of P. oceanica was distorted by a marked absorption increase at wavelength < 265 nm, presumably related to the release of hydrogen sulfide (HS−) associated with the anaerobic decomposition of seagrass leaves within the banquettes. Our results provide the first evidence that P. oceanica is a source of CDOM to the surrounding waters.


2012 ◽  
Vol 77 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Pierre Sabatier ◽  
Laurent Dezileau ◽  
Christophe Colin ◽  
Louis Briqueu ◽  
Frédéric Bouchette ◽  
...  

A high-resolution record of paleostorm events along the French Mediterranean coast over the past 7000 years was established from a lagoonal sediment core in the Gulf of Lions. Integrating grain size, faunal analysis, clay mineralogy and geochemistry data with a chronology derived from radiocarbon dating, we recorded seven periods of increased storm activity at 6300–6100, 5650–5400, 4400–4050, 3650–3200, 2800–2600, 1950–1400 and 400–50 cal yr BP (in the Little Ice Age). In contrast, our results show that the Medieval Climate Anomaly (1150–650 cal yr BP) was characterised by low storm activity.The evidence for high storm activity in the NW Mediterranean Sea is in agreement with the changes in coastal hydrodynamics observed over the Eastern North Atlantic and seems to correspond to Holocene cooling in the North Atlantic. Periods of low SSTs there may have led to a stronger meridional temperature gradient and a southward migration of the westerlies. We hypothesise that the increase in storm activity during Holocene cold events over the North Atlantic and Mediterranean regions was probably due to an increase in the thermal gradient that led to an enhanced lower tropospheric baroclinicity over a large Central Atlantic-European domain.


2010 ◽  
Vol 31 (4) ◽  
pp. 555-565 ◽  
Author(s):  
Monica Previati ◽  
Marco Palma ◽  
Giorgio Bavestrello ◽  
Carla Falugi ◽  
Carlo Cerrano

2012 ◽  
Vol 4 (1) ◽  
pp. 96-103 ◽  
Author(s):  
D. S. Malik ◽  
Umesh Bharti

The present contribution encompasses on plankton and biological productivity as ecological indicator for identifying the ecological quality of Sahastradhara stream (between 27 km stream stretches), located in the Doon Valley of Garhwal region in India. Monthly sampling from all the sampling sites was made for a period of 12 months (May 2009 – April 2010) at 9:00-11: 00 AM. A total of 40 taxa from different classes of plankton and zooplankton were reported. The phytoplankton (32 sp.) was found being the most abundant taxa than zooplankton (9 sp.) inSahastradhara stream. Fluctuation in the phytoplankton density was recorded highest (1536 unit/l) during winter and lowest (20 unit/l) during monsoon. Zooplanktons were reported to be maximum (147 unit/l) during summer and minimum (3 unit/l) during monsoon. The total diatoms were reported highest (1022unit/l) during starting the winter and lowest (4 unit/l) during monsoon. Green algae and blue green algae were reported to be maximum during winter and minimum during summer. The Shannon-wiener diversity index calculated for the density ofBacillariophyceae (0.2180-0.366), Chlorophyceae (0.208-0.367) and Cyanophyceae (0.391-0.366) and correlation was made between Plankton biomass and physico-chemical parameters to analyses the relative features of the both variables. The density of plankton and biological productivity were influenced by disturbances in the photic zone and indiscriminate anthropogenic activities for tourist development resulted aquatic habitat degradation in stream ecosystem.


2019 ◽  
Vol 28 (5) ◽  
pp. 920-922 ◽  
Author(s):  
David Moreira ◽  
Purificación López‐García

2009 ◽  
Vol 4 (4) ◽  
pp. 671-674 ◽  
Author(s):  
Verónica Fuentes ◽  
Dacha Atienza ◽  
Josep-Maria Gili ◽  
Jennifer Purcell

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2158 ◽  
Author(s):  
Mari-Carmen Pineda ◽  
Beatriz Lorente ◽  
Susanna López-Legentil ◽  
Creu Palacín ◽  
Xavier Turon

Spatio-temporal changes in genetic structure among populations provide crucial information on the dynamics of secondary spread for introduced marine species. However, temporal components have rarely been taken into consideration when studying the population genetics of non-indigenous species. This study analysed the genetic structure ofStyela plicata,a solitary ascidian introduced in harbours and marinas of tropical and temperate waters, across spatial and temporal scales. A fragment of the mitochondrial gene Cytochrome Oxidase subunit I (COI) was sequenced from 395 individuals collected at 9 harbours along the NW Mediterranean coast and adjacent Atlantic waters (> 1,200 km range) at two time points 5 years apart (2009 and 2014). The levels of gene diversity were relatively low for all 9 locations in both years. Analyses of genetic differentiation and distribution of molecular variance revealed strong genetic structure, with significant differences among many populations, but no significant differences among years. A weak and marginally significant correlation between geographic distance and gene differentiation was found. Our results revealed spatial structure and temporal genetic homogeneity inS. plicata, suggesting a limited role of recurrent, vessel-mediated transport of organisms among small to medium-size harbours. Our study area is representative of many highly urbanized coasts with dense harbours. In these environments, the episodic chance arrival of colonisers appears to determine the genetic structure of harbour populations and the genetic composition of these early colonising individuals persists in the respective harbours, at least over moderate time frames (five years) that encompass ca. 20 generations ofS. plicata.


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