40 research outputs found
Listado con primeros registros de los equinodermos del norte de Túnez (Mediterráneo central)
Tunisia occupies a strategic biogeographic position in the Mediterranean Sea and the Strait of Sicily is considered a biogeographical boundary that separates the eastern and western basins. Despite the importance of marine biodiversity in Tunisia, the few studies of Echinodermata fauna in this region data from long ago. In order to update and produce a validated checklist of the echinoderms that occur in northern Tunisia, a study of this phylum was carried out between 2012 and 2016. Forty-five species were inventoried and distributed into the five living Echinodermata classes (Crinoidea, Asteroidea, Ophiuroidea, Echinoidea and Holothuroidea). New occurrences of four species from Tunisian marine waters [Asterina pancerii (Gasco, 1876), Luidia atlantidea (Madsen, 1950), Ophiactis virens (Sars, 1859) and Leptopentacta tergestina (Sars, 1857)], are cited and discussed here for the first time.Túnez ocupa un área biogeográfica estratégica en el Mediterráneo. El estrecho tunecino-siciliano es considerado una frontera biogeográfica que separa las cubetas oriental y occidental. Sin embargo, a pesar de su interés, los estudios sobre la fauna de equinodermos de Túnez son antiguos y escasos. Con el fin de elaborar el inventario de los equinodermos de la región septentrional del mar de Túnez, se realizó un estudio de este filum entre los años 2012 y 2016. Se han inventariado cuarenta y cinco especies pertenecientes a las cinco clases actuales de Echinodermata (Crinoidea, Asteroidea, Ophiuroidea, Echinoidea y Holothuroidea). Cuatro especies [Asterina pancerii (Gasco, 1876), Luidia atlantidea (Madsen, 1950), Ophiactis virens (Sars, 1859) y Leptopentacta tergestina (Sars, 1857)] se han recolectado por primera vez en estas aguas
Cartografía bionómica del poblamiento bentónico de las islas del Mar Menor. 1: Islas Perdiguera y del Barón.
Bionomic cartography of the benthic assem blages of the Mar Menor lagoon islands. 1: Perdiguera and Barón islands. The bionomic composition and cartography is given of the hard and soft bottoms of two of the islands of the Mar Menor lagoon, an hypersaline water basin on the SE Spain coast. The tittoral wnation etages are narrow (because of the reduced hydrodynamism), reduced in number (the circalittoral etage laeks due to lhe lagoon shallowness) and of empoverished faunistie and floristie composition when compared with the neighboring Mediterranean ones (because of the environmenta1 stresses associated to an hypersaline lagoon environment). The rocky substrates are also reduced in extent, and lhere are virtually no sciaphi1ic communities. In general, lhe benthie assemblages are those eorresponding to the euryhaline and eurytherma1 lagoon community of PÉRES & PICARD ( 1 964), bul the large size of lhe lagoon and i lS increasing water exchangc with the Mediterranean have somewhat diversified the benthic communities, which now lie half way between the typically marine and those proper of Mediterranean coastal lagoons. The main communities are those dominatcd by macrophytes on 50ft bOlloms (infralittoral etage): the meadows of Cau/erpa prolifera and of Caulerpa-Cymodocea on muddy bonoms, and those of Cymodocea nodosa on sandy ones. PhOlOphilic algae communities, of varying but tinúted composition, are restricted to the hard bottoms.Bionomic maps and represenlative transects of these two islands bottoms are given; the other islands of the lagoon will be dealt with in a fortheoming paper, where the overall bionomic features of the lagoon benthic eommunities wiU be treated.B ionomic cartography of the benthic assem blages of the Mar Menor lagoon islands. 1: Perdiguera and Barón islands. The bionomic composition and cartography is given of the hard and soft bottoms of two of the islands of the Mar Menor lagoon, an hypersaline water basin on the SE Spain coasl. The tittoral wnation etages are narrow (because of the reduced hydrodynamism), reduced in number (the circalittoral etage laeks due to lhe 1agoon shallowness) and of empoverished faunistie and floristie eomposition when compared wilh the neighboring Mediterranean ones (because of the environmenta1 stresses associated to an hypersaline lagoon environment). The rocky substrates are also reduced in extent, and lhere are virtually no sciaphi1ic communities. In general, lhe benthie assemblages are those eorresponding to the euryhaline and eurytherma1 lagoon community of PÉRES & PICARD ( 1 964), bul the large size of lhe lagoon and i lS increasing water exchangc with the Mediterranean have somewhat diversified the benthic communities, which now lie half way between the typically marine and those proper of Mediterranean coastal lagoons. The main communities are those dominatcd by macrophytes on 50ft bOlloms (infralittoral etage): the meadows of Cau/erpa prolifera and of Caulerpa-Cymodocea on muddy bonoms, and those of Cymodocea nodosa on sandy ones. PhOlOphilic algae communities, of varying but tinúted composition, are restricted to the hard bottoms.Bionomic maps and represenlative transects of these two islands bottoms are given; the other islands of the lagoon will be dealt with in a fortheoming paper, where the overall bionomic features of the lagoon benthic eommunities wiU be treated
TÉCNICAS DE RECOLECCIÓN Y ESTUDIO EN LA CLASE HOLOTHUROIDEA. 1. GENERALIDADES, SISTEMÁTICA, ECOLOGÍA, BIOLOGÍA Y COMPORTAMIENTO
Studies about holothunans in Spain are scarce and they are reduced to some faunistic or systematic notes. In this paper some of the methods habitually employed in the different aspects of the systematic (sampling and preservation, preparation of spicules. calcareous ring, etc.), biological (reproduction, development, growth, nutrition and activity) and ecological (evaluation of the populations, incidence of the environmental factors) studies of this group of echinoderms are presented.En España los estudios sobre las holoturias son escasos y se reducen a algunas notas faunísticas o sistemáticas. En este trabajo se presentan algunas de las técnicas empleadas habitualmente por los investigadores en los distintos aspectos de la sistemática (recolección y conservación, preparación de espículas, anillo calcáreo, etc.), biología (reproducción, desarrollo, crecimiento, nutrición, actividad) y ecología (evaluación de las poblaciones. incidencia de los factores ambientales) de este grupo de equinodermos
Density dependence in marine protected populations: a review
The cessation or reduction of fishing in marine protected areas (MPAs) should promote an increase in abundance and mean size and age of previously exploited populations. Thus density-dependent changes in life-history characteristics should occur when populations are allowed to recover in MPAs. In this review, we synthesize the existing information on resource limitation in marine ecosystems, density-dependent changes in life-history traits of exploited populations and evidence for biomass export from MPAs. Most evidence for compensatory changes in biological variables has been derived from observations on populations depleted by high fishing mortality or on strong year classes, but these changes are more evident in juveniles than in adults and in freshwater rather than in marine systems. It is unclear if adults of exploited marine populations are resource limited. This may suggest that exploited populations are controlled mainly by density-independent processes, which could be a consequence of the depleted state of most exploited populations. MPAs could be a useful tool for testing these hypotheses. If we assume that resources become limiting inside MPAs, it is plausible that, if suitable habitats exist, mobile species will search for resources outside of the MPAs, leading to export of biomass to areas which are fished. However, it is not possible to establish from the available data whether this export will be a response to resource limitation inside the MPAs, the result of random movements across MPA boundaries or both. We discuss the implications of this process for the use of MPAs as fisheries management tools.Financial support was provided by the EU CEC DGXII – MAST III contract number: MAS3-ct97-0155
Reviewing the ecosystem services, societal goods, and benefits of marine protected areas
Marine protected areas (MPAs) are globally important environmental management tools that provide protection from the effects of human exploitation and activities, supporting the conservation of marine biological diversity, habitats, ecosystems and the processes they host, as well as resources in a broad sense. Consequently, they are also expected to manage and enhance marine ecosystem services and material, non-material, consumptive and non-consumptive goods, and benefits for humans. There is however certain confusion on what constitutes an ecosystem service, and it is not always easy to distinguish between them and societal benefits. The main nuance is that an ecosystem service is the aptitude an ecosystem has or develops naturally or as consequence of a management action, and that manifests through its own properties (productivity, diversity, stability, quality of its key parameters, etc.), while a societal benefit is the economic or other profitability (emotional, educational, scientific, etc.) that humans obtain from said service or quality. In this work, 268 publications, together with our own experiences in the different investigations carried out in the MPAs that are part of the BiodivERsA3-2015-21 RESERVEBENEFIT European project, have been selected, reviewed and discussed to analyze the knowledge status of the expected ecosystem services of MPAs and the societal benefits derived from them, sometimes providing information on their evidence, when they exist. We define and classify the effects of protection, ecosystem services and societal benefits and elaborate a conceptual model of the cause-effect relationships between them
Long-Term Dynamic in Nutrients, Chlorophyll a, and Water Quality Parameters in a Coastal Lagoon During a Process of Eutrophication for Decades, a Sudden Break and a Relatively Rapid Recovery
Coastal lagoons are considered among the marine habitats with the highest biological productivity, and support a great variety of human activities and pressures that make them especially vulnerable to trophic imbalances. While dystrophic crises are common in many lagoons, others like the Mar Menor show homeostatic mechanisms, high resilience, and clear waters. This paper analyses the water column descriptors dynamic during the last 22 years in this coastal lagoon, in the context of a eutrophication process produced by an increase in nutrient inputs, mainly derived from agriculture. Despite water column nitrate concentration increased by one order of magnitude, the lagoon maintained homeostatic regulation for two decades, keeping the water transparency and relatively low levels of nutrients and chlorophyll a (Prebreak phase), followed by a sudden change of state in 2016 with an abrupt increase in average nutrients and chlorophyll a concentration and loss of water transparency (Break phase), and a relatively rapid recovery after the reduction of nutrient discharges (Recovery phase). The activation of the regulation mechanisms seems to manifest through an ammonium production in the water column, as a consequence of the activity in the trophic web. The low correlation between chlorophyll a and nutrients concentration, mainly at small spatio-temporal scales, is in disagreement with eutrophication traditional models, and suggests a rapid response of primary producers to nutrient inputs and a zooplankton control in the short-term, which in turn is controlled by the rest of the trophic web components. Homeostatic properties that in the Mar Menor lagoon have provided resistance to eutrophication are based on several mechanisms: channeling its production toward the benthic system (maintaining high biomasses of primary producers, filter feeders, and detritivores), a top-down control of the pelagic trophic web exerted by ichthyoplankton and jellyfish, and exporting surplus production outside the system. Resilience of the system would be based on the high turnover in the species composition related to the restricted connectivity to the sea, the spatio-temporal variability of the environmental conditions, and the multiplicity of spatial–temporal scales involved in lagoon processes. TRIX index was sensitive to the trophic and water quality changes. However, in our study, its current score does not allow to anticipate or alert the eutrophication risk and the trophic breakpoint of the system
Unifying approaches to Functional Marine Connectivity for improved marine resource management: the European SEA-UNICORN COST Action
Truly sustainable development in a human-altered, fragmented marine environment subject to unprecedented climate change, demands informed planning strategies in order to be successful. Beyond a simple understanding of the distribution of marine species, data describing how variations in spatio-temporal dynamics impact ecosystem functioning and the evolution of species are required. Marine Functional Connectivity (MFC) characterizes the flows of matter, genes and energy produced by organism movements and migrations across the seascape. As such, MFC determines the ecological and evolutionary interdependency of populations, and ultimately the fate of species and ecosystems. Gathering effective MFC knowledge can therefore improve predictions of the impacts of environmental change and help to refine management and conservation strategies for the seas and oceans. Gathering these data are challenging however, as access to, and survey of marine ecosystems still presents significant challenge. Over 50 European institutions currently investigate aspects of MFC using complementary methods across multiple research fields, to understand the ecology and evolution of marine species. The aim of SEA-UNICORN, a COST Action within the European Union Horizon 2020 framework programme, is to bring together this research effort, unite the multiple approaches to MFC, and to integrate these under a common conceptual and analytical framework. The consortium brings together a diverse group of scientists to collate existing MFC data, to identify knowledge gaps, to enhance complementarity among disciplines, and to devise common approaches to MFC. SEA-UNICORN will promote co-working between connectivity practitioners and ecosystem modelers to facilitate the incorporation of MFC data into the predictive models used to identify marine conservation priorities. Ultimately, SEA-UNICORN will forge strong forward-working links between scientists, policy-makers and stakeholders to facilitate the integration of MFC knowledge into decision support tools for marine management and environmental policies
An overview of ecological status, vulnerability and future perspectives of European large shallow, semi-enclosed coastal systems, lagoons and transitional waters
The paper gives an overview of some of the large, shallow, semi-enclosed coastal systems (SECS) in
Europe, These SECS are important both from the ecological and the economic perspective (socioecological
systems) and provide many valuable ecosystem goods and services.
Although some of the systems are transitional waters under theWater Framework Directive, this is not
the case for all of the systems. The paper adopts a Driver-Pressure-State-Impact-Response approach to
analyse the ecological status, vulnerability and future perspectives of these systems in the context of
global change.This work has been supported by: the EUROMEDLAG federation, http://www.euromedlag.eu/lagoonsfederation/; EC 5FP grant agreement 00084 (DITTY), http://www.ecolag.univ-montp2.
fr/index.php?option¼com_content&task¼view&lang¼en&id¼226; EC 6FP grant agreement 036992 (SPICOSA),www.spicosa.eu/; the LOICZ project, http://www.loicz.org/.info:eu-repo/semantics/publishedVersio
Marine Protected Areas as a tool for fishery management and ecosystem conservation: an Introduction
Pycnogonid ecology in the Mar Menor (Murcia, SW Mediterranean)
The Mar Menor is a hypersaline coastal lagoon in the SW Mediterranean. A study of pycnogonids was based on 52 samples from the different benthic communities found in the lagoon, using 1001 individuals belonging to 5 species (Tanystylum conirostre, Achelia echinata, Ammothella longipes, A. appendiculata and Anoplodactylus pygmaeus), from infralittoral rock communities. Neither the meadows of Cymodocea nodosa, Caulerpa prolifera and Ruppia cirrhosa, nor the soft substrates revealed the presence of pycnogonids. All 5 species were found in the proximity of El Estacio channel (the main communication with the Mediterranean), while at sites within the lagoon only the first and last species were found. These were also the species with the highest population densities. Data about the abundance and development stages of the species, the diversity of samples and their affinity are reported. A study of the intermediary development between larva and juvenile is presented for Tanystylum conirostre