scholarly journals A coastal storms intensity scale for the Catalan sea (NW Mediterranean)

2011 ◽  
Vol 11 (9) ◽  
pp. 2453-2462 ◽  
Author(s):  
E. T. Mendoza ◽  
J. A. Jimenez ◽  
J. Mateo
Keyword(s):  
Energy Content ◽  
Western Mediterranean ◽  
Synoptic Situation ◽  
Spatial And Temporal Variability ◽  
Class Iii ◽  
Intensity Scale ◽  
Data Set ◽  
Catalan Coast ◽  
Content Variable ◽  
Nw Mediterranean

Abstract. A 5-class intensity scale for wave storms in the Catalan coast is presented. This has been done by analysing a storm data set which comprises 5 buoys during the period 1988/2008. The obtained classification improves the former proposal of Mendoza and Jiménez (2008) by better resolving spatial and temporal variability in wave storms in the area. The obtained classification reflects the increase in wave storm properties as the storm category increases. Because the selected classification parameter was the energy content which implicitly contains Hs and storm duration, this variable was used to define class limits; class I storms (24–250 m2 h), class II storms (251–500 m2 h), class III (501–700 m2 h), class IV storms (701–1200 m2 h) and class V storms (>1200 m2 h). The energy content variable was also used as proxy for induced hazards; the observed increase in energy content for higher classes reflected a significant increase in the intensity of the potential hazards. Lastly, the dominant synoptic situation for wave storms along the Catalan coast was the presence of a Mediterranean cyclone although a direct correspondence on cyclone's intensity over the western Mediterranean with wave energy content was not found.

scholarly journals Short-scale temporal variability of physical, biological and biogeochemical processes in the NW Mediterranean Sea: an introduction

2009 ◽  
Vol 6 (3) ◽  
pp. 453-461 ◽  
Author(s):  
V. Andersen ◽  
M. Goutx ◽  
L. Prieur ◽  
J. R. Dolan
Keyword(s):  
Mediterranean Sea ◽  
Temporal Variability ◽  
Time Course ◽  
Special Section ◽  
Zooplankton Community ◽  
Western Mediterranean ◽  
Trophic Levels ◽  
Data Set ◽  
Nw Mediterranean ◽  
Nw Mediterranean Sea

Abstract. In the framework of the PROOF-PECHE project (http://www.obs-vlfr.fr/proof/vt/op/ec/peche/pec.htm) a multi-disciplinary team performed experiments and collected samples during the DYNAPROC 2 cruise aboard the RV Thalassa from September to October in 2004. The cruise provided data on the functioning of the pelagic food web by sampling over a month long period in the NW Mediterranean Sea at a fixed station subject to weak horizontal advection currents during a period of hydrological stability. This paper describes the background of the cruise and provides an overview of the results derived from the campaign which constitute the special section. The major objective of the cruise was to assess the relative importance and variability of the pathways of carbon in the open ocean. Intensive sampling through 4 periods of 5 days each was accomplished at a site near the DYFAMED time-series site. The site was near stable in terms of hydrodynamics as there was some evidence of an intrusion of low-salinity coastal water. The cruise yielded a comprehensive data set acquired by sampling over a vertical spatial dimension (0–1000 m) and at high frequencies (ranging from every 3, 6, 12 and/or 24 h), unique for the summer to autumn transition in the North Western Mediterranean. Parameters investigated included the biochemical composition of dissolved organic matter (lipids), and the structure of bacterial communities, phytoplankton and zooplankton community compositions and abundances, as well as zooplankton metabolism, and particulate organic carbon fluxes. Nearly all the parameters described in this section, as well as reports appearing elsewhere, showed time-course variabilities of similar magnitude to those known from a previous study of the spring-summer seasonal transition, a period of marked hydrological change, at the same study site. Remarkably, the least variable characteristic of the system appeared to be the identities of the dominant taxa across several trophic levels (copepods, phytoplankton, ciliates, and bacteria) throughout the study period despite large shifts in stock sizes and fluxes. Thus, the studies of DYNAPROC 2 documented considerable temporal variability of stocks and rates in a system which was, from a hydrological and taxonomic point of view, relatively stable.

scholarly journals Short-scale temporal variability of physical, biological and biogeochemical processes in the NW Mediterranean Sea: an introduction

2008 ◽  
Vol 5 (6) ◽  
pp. 5233-5251 ◽  
Author(s):  
V. Andersen ◽  
M. Goutx ◽  
L. Prieur ◽  
J. R. Dolan
Keyword(s):  
Mediterranean Sea ◽  
Time Course ◽  
Special Section ◽  
Zooplankton Community ◽  
Spatial Dimension ◽  
Western Mediterranean ◽  
Major Product ◽  
Data Set ◽  
Nw Mediterranean ◽  
Nw Mediterranean Sea

Abstract. In the framework of the PROOF-PECHE project (www.obs-vlfr.fr/proof/vt/op/ec/peche/pec.htm) a multi-disciplinary team performed experiments and collected samples during the DYNAPROC2 cruise aboard the RV Thalassa from September to October in 2004. The cruise provided data on the functioning of the pelagic food web by sampling over a month long period in the NW Mediterranean Sea at a fixed station subject to weak horizontal advection currents during a period of hydrological stability. This paper describes the background of the cruise and provides an overview of the results derived from the campaign which constitute the special section. The major objective of the cruise was to assess the relative importance and variability of the pathways of carbon in the open ocean. Intensive sampling through 4 periods of 5 days each was accomplished a site near the DYFAMED time-series site. The site was near stable in terms of hydrodynamics as there was some evidence of an intrusion of low-salinity coastal water. One major product of the cruise was a comprehensive data set data set acquired by sampling at high frequencies (ranging from every 3, 6, 12 and/or 24 h) and over a vertical spatial dimension so far never explored (0–1000 m) in the North Western Mediterranean Sea. Parameters investigated included the biochemical composition of DOM (lipids), and the structure of bacterial communities, phytoplankton and zooplankton community compositions and abundances, as well as zooplankton metabolism, and particulate organic carbon fluxes. Nearly all the parameters described in this section, as well as reports appearing elsewhere, showed time-course variabilities of similar magnitude to those known from a previous study of the spring-summer seasonal transition, a period of marked hydrological change, at the same study site.

scholarly journals Biogeography of acoustic biodiversity of NW Mediterranean coralligenous reefs

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lucia Di Iorio ◽  
Manon Audax ◽  
Julie Deter ◽  
Florian Holon ◽  
Julie Lossent ◽  
...  
Keyword(s):  
Large Scale ◽  
Spatial Scales ◽  
Western Mediterranean ◽  
Ecosystem Functions ◽  
Marine Biodiversity ◽  
Predator Species ◽  
The North ◽  
Mediterranean Habitats ◽  
Geographical Regions ◽  
Nw Mediterranean

AbstractMonitoring the biodiversity of key habitats and understanding the drivers across spatial scales is essential for preserving ecosystem functions and associated services. Coralligenous reefs are threatened marine biodiversity hotspots that are challenging to monitor. As fish sounds reflect biodiversity in other habitats, we unveiled the biogeography of coralligenous reef sounds across the north-western Mediterranean using data from 27 sites covering 2000 km and 3 regions over a 3-year period. We assessed how acoustic biodiversity is related to habitat parameters and environmental status. We identified 28 putative fish sound types, which is up to four times as many as recorded in other Mediterranean habitats. 40% of these sounds are not found in other coastal habitats, thus strongly related to coralligenous reefs. Acoustic diversity differed between geographical regions. Ubiquitous sound types were identified, including sounds from top-predator species and others that were more specifically related to the presence of ecosystem engineers (red coral, gorgonians), which are key players in maintaining habitat function. The main determinants of acoustic community composition were depth and percentage coverage of coralligenous outcrops, suggesting that fish-related acoustic communities exhibit bathymetric stratification and are related to benthic reef assemblages. Multivariate analysis also revealed that acoustic communities can reflect different environmental states. This study presents the first large-scale map of acoustic fish biodiversity providing insights into the ichthyofauna that is otherwise difficult to assess because of reduced diving times. It also highlights the potential of passive acoustics in providing new aspects of the correlates of biogeographical patterns of this emblematic habitat relevant for monitoring and conservation.

scholarly journals Impact of mechanized clam dredging on the discarded megabenthic fauna on the Catalan coast (NW Mediterranean)

2021 ◽  
pp. 1-9
Author(s):  
Marc Baeta ◽  
Claudia Rubio ◽  
Françoise Breton
Keyword(s):  
Small Scale ◽  
Fishing Activity ◽  
Lethal Damage ◽  
Catalan Coast ◽  
Nw Mediterranean ◽  
Chamelea Gallina ◽  
Level Scale ◽  
Nw Mediterranean Sea ◽  
The Impact ◽  
Partial Damage

Abstract There is an important small-scale fishery using mechanized dredges and targeting clams (mainly wedge clam Donax trunculus and striped venus clam Chamelea gallina) along the Catalan coast (NW Mediterranean Sea). This study evaluated for the first time the discards and impact of mechanized clam dredging on the Catalan coast. To this end, three surveys were performed on board standard clam vessels (September and November 2016 and January 2017). Surveys were conducted in the three main clam fishing areas (Rosas Bay, South Barcelona and Ebro Delta). The composition of discards and the impact caused to discarded species was assessed using a three-level scale (undamaged; minor or partial damage; and lethal damage). Our study revealed that a large proportion of the catch (between 67–82% weight) is discarded. Even though about 63% of the discarded species were undamaged, 11% showed minor or partial damage and 26% lethal damage. Infaunal and epifaunal species with soft-body or fragile shells were the most impacted by the fishing activity (e.g. the sea urchin Echinocardium mediterraneum (~89%) and the bivalve Ensis minor (~74%)). Our results showed different levels of impact by target species and fishing area.

Life cycle of the jellyfish Rhizostoma pulmo (Scyphozoa: Rhizostomeae) and its distribution, seasonality and inter-annual variability along the Catalan coast and the Mar Menor (Spain, NW Mediterranean)

2011 ◽  
Vol 158 (10) ◽  
pp. 2247-2266 ◽  
Author(s):  
Verónica Fuentes ◽  
Ilka Straehler-Pohl ◽  
Dacha Atienza ◽  
Ignacio Franco ◽  
Uxue Tilves ◽  
...  
Keyword(s):  
Life Cycle ◽  
Annual Variability ◽  
Catalan Coast ◽  
Mar Menor ◽  
Nw Mediterranean

European hake (Merluccius merluccius, Linnaeus 1758) spillover analysis using VMS and landings data in a no-take zone in the northern Catalan coast (NW Mediterranean)

2021 ◽  
Vol 237 ◽  
pp. 105870 ◽  
Author(s):  
Joan Sala-Coromina ◽  
Jose Antonio García ◽  
Paloma Martín ◽  
Ulla Fernandez-Arcaya ◽  
Laura Recasens
Keyword(s):  
Merluccius Merluccius ◽  
Catalan Coast ◽  
Nw Mediterranean ◽  
European Hake

scholarly journals Bayesian trend analysis of extreme wind using observed and hindcast series off the Catalan coast, NW Mediterranean Sea

2014 ◽  
Vol 14 (9) ◽  
pp. 2387-2397 ◽  
Author(s):  
M. I. Ortego ◽  
J. J. Egozcue ◽  
R. Tolosana-Delgado
Keyword(s):  
Generalized Pareto Distribution ◽  
Western Mediterranean ◽  
Quality Data ◽  
Occurrence Rate ◽  
Data Series ◽  
Model Parameters ◽  
Storm Events ◽  
Average Wind Speed ◽  
Magnitude Distribution ◽  
Catalan Coast

Abstract. It has been suggested that climate change might modify the occurrence rate and magnitude of large ocean-wave and wind storms. The hypothesised reason is the increase of available energy in the atmosphere–ocean system. Forecasting models are commonly used to assess these effects, given that good-quality data series are often too short. However, forecasting systems are often tuned to reproduce the average behaviour, and there are concerns on their relevance for extremal regimes. We present a methodology of simultaneous analysis of observed and hindcast data with the aim of extracting potential time drifts as well as systematic regime discrepancies between the two data sources. The method is based on the peak-over-threshold (POT) approach and the generalized Pareto distribution (GPD) within a Bayesian estimation framework. In this context, storm events are considered points in time, and modelled as a Poisson process. Storm magnitude over a reference threshold is modelled with a GPD, a flexible model that captures the tail behaviour of the magnitude distribution. All model parameters, i.e. shape and location of the magnitude GPD and the Poisson occurrence rate, are affected by a trend in time. Moreover, a systematic difference between parameters of hindcast and observed series is considered. Finally, the posterior joint distribution of all these trend parameters is studied using a conventional Gibbs sampler. This method is applied to compare hindcast and observed series of average wind speed at a deep buoy location off the Catalan coast (NE Spain, western Mediterranean; buoy data from 2001; REMO wind hindcasting from 1958 on). Appropriate scale and domain of attraction are discussed, and the reliability of trends in time is addressed.

Seasonal ecosystem vulnerability to climatic anomalies in the Mediterranean

2021 ◽  
Author(s):  
Johannes Vogel
Keyword(s):  
Soil Moisture ◽  
Mediterranean Basin ◽  
Eastern Mediterranean ◽  
Western Mediterranean ◽  
Ecosystem Productivity ◽  
Data Set ◽  
Ecosystem Vulnerability ◽  
Dry Conditions ◽  
The Mediterranean ◽  
The Mediterranean Basin

<p>The ecosystems of the Mediterranean Basin are particularly prone to climate change and related alterations in climatic anomalies. The seasonal timing of climatic anomalies is crucial for the assessment of the corresponding ecosystem impacts; however, the incorporation of seasonality is neglected in many studies. We quantify ecosystem vulnerability by investigating deviations of the climatic drivers temperature and soil moisture during phases of low ecosystem productivity for each month of the year over the period 1999 – 2019. The fraction of absorbed photosynthetically active radiation (FAPAR) is used as a proxy for ecosystem productivity. Air temperature is obtained from the reanalysis data set ERA5 Land and soil moisture and FAPAR satellite products are retrieved from ESA CCI and Copernicus Global Land Service, respectively. Our results show that Mediterranean ecosystems are vulnerable to three soil moisture regimes during the course of the year. A phase of vulnerability to hot and dry conditions during late spring to midsummer is followed by a period of vulnerability to cold and dry conditions in autumn. The third phase is characterized by cold and wet conditions coinciding with low ecosystem productivity in winter and early spring. These phases illustrate well the shift between a soil moisture-limited regime in summer and an energy-limited regime in winter in the Mediterranean Basin. Notably, the vulnerability to hot and dry conditions during the course of the year is prolonged by several months in the Eastern Mediterranean compared to the Western Mediterranean. Our approach facilitates a better understanding of ecosystem vulnerability at certain stages during the year and is easily transferable to other study areas and ecoclimatological variables.</p>

scholarly journals Assessment of the importance of the current-wave coupling in the shelf ocean forecasts

Ocean Science ◽  
2007 ◽  
Vol 3 (3) ◽  
pp. 345-362 ◽  
Author(s):  
G. Jordà ◽  
R. Bolaños ◽  
M. Espino ◽  
A. Sánchez-Arcilla
Keyword(s):  
Surface Wind ◽  
Circulation Model ◽  
Wave Model ◽  
Western Mediterranean ◽  
Stokes Drift ◽  
Coupled Modelling ◽  
Wave Refraction ◽  
Waves And Currents ◽  
Nw Mediterranean ◽  
Sequential Coupling

Abstract. The effects of wave-current interactions on shelf ocean forecasts is investigated in the framework of the MFSTEP (Mediterranean Forecasting System Project Towards Enviromental Predictions) project. A one way sequential coupling approach is adopted to link the wave model (WAM) to the circulation model (SYMPHONIE). The coupling of waves and currents has been done considering four main processes: wave refraction due to currents, surface wind drag and bottom drag modifications due to waves, and the wave induced mass flux. The coupled modelling system is implemented in the southern Catalan shelf (NW Mediterranean), a region with characteristics similar to most of the Mediterranean shelves. The sensitivity experiments are run in a typical operational configuration. The wave refraction by currents seems to be not very relevant in a microtidal context such as the western Mediterranean. The main effect of waves on current forecasts is through the modification of the wind drag. The Stokes drift also plays a significant role due to its spatial and temporal characteristics. Finally, the enhanced bottom friction is just noticeable in the inner shelf.

Sign in / Sign up

Export Citation Format

Share Document