An ecosystem-based approach to evaluate the ecological quality of Mediterranean undersea caves

A theoretical model of structure and functioning was constructed for the Mediterranean undersea cave ecosystem. This model integrates almost all representative components of the cave ecosystem and gives an idea of their faunal compositions, characteristics and related interactions.This model constitutes the basis of the Ecosystem-Based Quality Index (EBQI) of the European Union's Marine Strategy Framework Directive, which aims at evaluating the ecological quality of an ecosystem. It is based on four crucial complementary elements: (i) each component was weighted in accordance with its importance in determining the structure and functioning of the cave ecosystem; (ii) a suite of relevant parameters were defined to assess the ecological state of each component of the cave ecosystem; (iii) these parameters were aggregated into one relevant index, the Cave EBQI (CavEBQI), to summarize the quality evaluation for each cave site; (iv) each value of ecological state is accompanied by a Confidence Index as a measure of its reliability.The CavEBQI was used on 22 Mediterranean undersea caves of France and Italy. Disparities of ecological quality were found among caves but most of them ranged from moderate to high ecological quality. For some caves, no conclusion can be drawn when our method predicts a poor reliability of the evaluation of their ecological quality.This ecosystem-based evaluation of the quality of undersea caves seems to be a powerful tool, with the advantage of being based on almost all its components, rather than just on a few species. It is accompanied by a measure of its reliability, hence it provides a reliable idea of the ecological state of the entire ecosystem at each cave site. Monitoring the ecological state of caves and the effects of disturbances over large geographic and temporal scales is made possible with CavEBQI. Applying the same method to other ecosystems, can provide an integrated view of a marine region, which is essential when addressing questions about protection, conservation and restoration.     

The law of the sea and regional fisheries policy

Abstract

The consequences of the inevitable acceptance of extended jurisdiction and its impact on fisheries policy in the South Pacific are considered within the framework of the principles outlined at the Third Session of the United Nations Law of the Sea Conference. It is pointed out that the fisheries resources of the region considered are dominated by highly migratory species, particularly tunas, and that the management of the fisheries on these species and the conservation of the species themselves will require comprehensive regional cooperation. Considering the common interests of the developing countries of the region and their comparative lack of experience in fisheries management and in surveillance and enforcement capabilities, it is argued that a regional fisheries agency is required. A wide range of possible functions for such a body is discussed and a three‐phase approach to the development of the agency is proposed.     

The analysis of convergence in ecological indicators: An application to the Mediterranean fisheries

Ecological indicators are increasingly used to examine the evolution of natural ecosystems and the impacts of human activities. Assessing their trends to develop comparative analyses is essential. We introduce the analysis of convergence, a novel approach to evaluate the dynamic and trends of ecological indicators and predict their behavior in the long-term. Specifically, we use a non-parametric estimation of Gaussian kernel density functions and transition probability matrix integrated in the R software. We validate the performance of our methodology through a practical application to three different ecological indicators to study whether Mediterranean countries converge towards similar fisheries practices. We focus on how distributions evolve over time for the Marine Trophic Index, the Fishing in Balance Index and the Expansion Factor during 1950–2010. Results show that Mediterranean countries persist in their fishery behaviors throughout the time series, although a tendency towards similar negative effects on the ecosystem is apparent in the long-term. This methodology can be easily reproduced with different indicators and/or ecosystems in order to analyze ecosystem dynamics.     

Contemporary genetic structure and postglacial demographic history of the black scorpionfish,Scorpaena porcus,in the Mediterranean and the Black Seas

Understanding the distribution of genetic diversity in the light of past demographic events linked with climatic shifts will help to forecast evolutionary trajectories of ecosystems within the current context of climate change. In this study, mitochondrial sequences and microsatellite loci were analysed using traditional population genetic approaches together with Bayesian dating and the more recent approximate Bayesian computation scenario testing. The genetic structure and demographic history of a commercial fish, the black scorpionfish, Scorpaena porcus, was investigated throughout the Mediterranean and Black Seas. The results suggest that the species recently underwent population expansions, in both seas, likely concomitant with the warming period following the Last Glacial Maximum, 20 000 years ago. A weak contemporaneous genetic differentiation was identified between the Black Sea and the Mediterranean Sea. However, the genetic diversity was similar for populations of the two seas, suggesting a high number of colonizers entered the Black Sea during the interglacial period and/or the presence of a refugial population in the Black Sea during the glacial period. Finally, within seas, an east/west genetic differentiation in the Adriatic seems to prevail, whereas the Black Sea does not show any structured spatial genetic pattern of its population. Overall, these results suggest that the Black Sea is not that isolated from the Mediterranean, and both seas revealed similar evolutionary patterns related to climate change and changes in sea level.     

The microcopepod fauna in the Eastern Mediterranean and Arabian Seas: a comparison with the Red Sea fauna

Multiple opening-closing nets of 0.05 mm mesh size were employed to study the community structure and vertical distribution of microcopepods at selected stations in the Red Sea, Arabian Sea and Eastern Mediterranean Sea down to a maximum depth of 1850 m. Calanoids, cyclopoids (Oithona and Paroithona) and poecilostomatoids (mainly Oncaea) were the 3 most abundant orders. In the epipelagic zone (0–100 m), these orders occurred at similar abundance levels, whereas in the meso- and bathypelagic zones the poecilostomatoid genus Oncaea dominated numerically by about 60–80% of all copepodids.The species diversity of Oncaea in the Red Sea is compared with preliminary results from the two adjacent regions. In the deep Eastern Mediterranean Sea, the number of species appears to be similar to that in the deep Red Sea and low as compared to the deep Arabian Sea. In this latter area an extremely speciose Oncaea fauna was found at depth below the oxygen-minimum-zone (900–1850 m). The results are related to the differences in the hydrographic conditions of these 3 areas.     

Benthic macrophyte metrics as bioindicators of water quality: towards overcoming typological boundaries and methodological tradition in Mediterranean and Black Seas

Benthic macrophyte communities of different substratum types (soft, hard) were studied in eleven differently impacted sites belonging in two different water typologies (transitional waters: Lesina Lagoon, Varna Lake; coastal waters: Varna Bay) and two ecoregions (Mediterranean Sea, Black Sea). Species lists were compiled for each study site, 20 taxa were found at Lesina and Varna Lake and Bay, and the abundance of each taxon was determined at each site. The relationship between nine metrics related to community structure [species richness, % of total coverage, dry biomass (g/m^?2), and cluster and multi-dimensional scaling plot of Bray–Curtis similarity] and function [Ecological Status Group I % coverage, ESG II % coverage, Ecological Evaluation Index (EEI-c) and Ecological Index (EI_EEI)] and key abiotic factors and an anthropogenic stress index (EnII) were studied. A strong relationship (Spearman rank correlation coefficient ρ ≤ ?0.89; R ² ≥ 0.89) between anthropogenic stress and functional indices, EEI-c and EI_EEI, was found. The structural index ‘species richness’ correlated negatively with EnII and positively with salinity, demonstrating a freshwater and confinement influence on species diversity. EEI-c and EI_EEI indices classified the studied sites and locations in different Ecological Status Classes in accordance with the anthropogenic stress gradient.     

Polo kinase and Asp are needed to promote the mitotic organizing activity of centrosomes

Interfering with the activity of polo-like kinases can lead to the formation of monopolar spindles. Polo-like kinases also regulate mitotic entry, activation of the anaphase-promoting complex and the necessary preconditions for cytokinesis. Similarities between the phenotypes of the Drosophila mutants asp and polo point towards a common role in spindle pole function. The abnormal spindles of asp mutants are bipolar but have disorganized broad poles at which gamma-tubulin has an abnormal distribution. Moreover, the synergism or of polo1 aspE3 double mutants indicates a possible involvement of these genes in a common process. Asp is a microtubule-associated protein of relative molecular mass 220,000 (Mr 220K) found at the face of the centrosome that contacts spindle microtubules. In partially purified centrosomes, it is required with gamma-tubulin to organize microtubule asters. Here, we show that Asp is the previously identified Mr 220K substrate of Polo kinase. Polo phosphorylates Asp in vitro, converting it into an MPM2 epitope. Polo and Asp proteins immunoprecipitate together and exist as part of a 25-38S complex. Extracts of polo-derived embryos are unable to restore the ability of salt-stripped centrosomes to nucleate microtubule asters. This can be rescued by addition of phosphorylated Asp or active Polo kinase.     

Coordinating proliferation and tissue specification to promote regional identity in the Drosophila head

The Decapentaplegic and Notch signaling pathways are thought to direct regional specification in the Drosophila eye-antennal epithelium by controlling the expression of selector genes for the eye (Eyeless/Pax6, Eyes absent) and/or antenna (Distal-less). Here, we investigate the function of these signaling pathways in this process. We find that organ primordia formation is indeed controlled at the level of Decapentaplegic expression but critical steps in regional specification occur earlier than previously proposed. Contrary to previous findings, Notch does not specify eye field identity by promoting Eyeless expression but it influences eye primordium formation through its control of proliferation. Our analysis of Notch function reveals an important connection between proliferation, field size, and regional specification. We propose that field size modulates the interaction between the Decapentaplegic and Wingless pathways, thereby linking proliferation and patterning in eye primordium development.     

The temporal response to drought in a Mediterranean evergreen tree: comparing a regional precipitation gradient and a throughfall exclusion experiment

Like many midlatitude ecosystems, Mediterranean forests will suffer longer and more intense droughts with the ongoing climate change. The responses to drought in long‐lived trees differ depending on the time scale considered, and short‐term responses are currently better understood than longer term acclimation. We assessed the temporal changes in trees facing a chronic reduction in water availability by comparing leaf‐scale physiological traits, branch‐scale hydraulic traits, and stand‐scale biomass partitioning in the evergreen Quercus ilex across a regional precipitation gradient (long‐term changes) and in a partial throughfall exclusion experiment (TEE, medium term changes). At the leaf scale, gas exchange, mass per unit area and nitrogen concentration showed homeostatic responses to drought as they did not change among the sites of the precipitation gradient or in the experimental treatments of the TEE. A similar homeostatic response was observed for the xylem vulnerability to cavitation at the branch scale. In contrast, the ratio of leaf area over sapwood area (LA/SA) in young branches exhibited a transient response to drought because it decreased in response to the TEE the first 4 years of treatment, but did not change among the sites of the gradient. At the stand scale, leaf area index (LAI) decreased, and the ratios of stem SA to LAI and of fine root area to LAI both increased in trees subjected to throughfall exclusion and from the wettest to the driest site of the gradient. Taken together, these results suggest that acclimation to chronic drought in long‐lived Q. ilex is mediated by changes in hydraulic allometry that shift progressively from low (branch) to high (stand) organizational levels, and act to maintain the leaf water potential within the range of xylem hydraulic function and leaf photosynthetic assimilation.     

Spearfishing regulation benefits artisanal fisheries: the ReGS indicator and its application to a multiple-use Mediterranean marine protected area

The development of fishing efficiency coupled with an increase of fishing effort led to the overexploitation of numerous natural marine resources. In addition to this commercial pressure, the impact of recreational activities on fish assemblages remains barely known. Here we examined the impact of spearfishing limitation on resources in a marine protected area (MPA) and the benefit it provides for the local artisanal fishery through the use of a novel indicator. We analysed trends in the fish assemblage composition using artisanal fisheries data collected in the Bonifacio Strait Natural Reserve (BSNR), a Mediterranean MPA where the spearfishing activity has been forbidden over 15% of its area. Fish species were pooled into three response groups according to their target level by spearfishing. We developed the new flexible ReGS indicator reflecting shifts in species assemblages according to the relative abundance of each response group facing external pressure. The catch per unit effort (CPUE) increased by ca. 60% in the BSNR between 2000 and 2007, while the MPA was established in 1999. The gain of CPUE strongly depended on the considered response group: for the highly targeted group, the CPUE doubled while the CPUE of the untargeted group increased by only 15.5%. The ReGS value significantly increased from 0.31 to 0.45 (on a scale between 0 and 1) in the general perimeter of this MPA while it has reached a threshold of 0.43, considered as a reference point, in the area protected from spearfishing since 1982. Our results demonstrated that limiting recreational fishing by appropriate zoning in multiple-use MPAs represents a real benefit for artisanal fisheries. More generally we showed how our new indicator may reveal a wide range of impacts on coastal ecosystems such as global change or habitat degradation.     

The precautionary approach in fisheries management: the devil is in the details

The William and Lenore Mote International Symposium 'Targets, thresholds and the burden of proof in fishery management' was held at the Mote Marine Laboratory, Sarasota, FL, USA, from 30 October to 2 November 2000.     

The construction of a scientific model: Otto Warburg and the building block strategy

In the years 1919 to 1923, Otto Warburg published four papers that were to revolutionise the field of photosynthesis. In these articles, he introduced a number of new techniques to measure the rate of photosynthesis, put forward a new model of the mechanism and added a completely new perspective to the topic by attempting to establish the process’s efficiency in terms of the light quantum requirement. In this paper I trace the roots of Warburg’s series of contributions to photosynthesis research by exploring three different contexts of inspiration: Warburg’s own research into cell respiration, his father’s work on the quantum yield of photochemical reactions in general and the photosynthesis work carried out by Richard Willstätter and Arthur Stoll. When these influences are considered together, it becomes clear that Warburg implemented a Building Block Strategy in his research: rather than inventing his photosynthesis model from scratch, he availed himself of fragments from other contexts, which he then recombined in a new and innovative way. This way of working is considered to be standard practice in scientific research.     

Identification of the Channelrhodopsin Genes in the Green and Cryptophytic Algae from the White and Black Seas

Biochemistry (Moscow) - Due to the unique capability of modulating cell membrane potential upon photoactivation, channelrhodopsins of green (Chlorophyta) and cryptophytic (Cryptophyta) algae are...     

From depth to regional spatial genetic differentiation of Eunicella cavolini in the NW Mediterranean

Connectivity studies in the marine realm are of great importance to understand the evolutionary potential of populations in a context of growing pressures on the marine environment. Here, we investigated the effect of the local, regional, and depth spatial scale on the population genetic structure of the yellow gorgonian Eunicella cavolini, one of the most common octocoral species of the Mediterranean hard-bottom communities. This species, along with other sessile metazoans typical of coralligenous ecosystems, plays an important role in supporting biodiversity, but is also impacted by direct and indirect consequences of human activities, such as physical destruction or mortality events due to thermal anomalies. Samples were taken from 15 sites located in the Ligurian Sea (NW Mediterranean) in two adjacent regions 100 kilometres apart, i.e. from the areas of Marseille (France) and Portofino (Genoa, Italy), and were analysed using six microsatellite loci. A pattern of isolation by distance was observed at the regional as well as the local scales. Although E. cavolini showed less genetic structure than other Mediterranean octocorallian species, we observed a significant genetic differentiation between populations a few kilometres apart. A low genetic differentiation was also observed between shallow and deep populations. The occurrence of genetically differentiated populations of E. cavolini at the scale of kilometres has important consequences for the management of this species and of the associated communities.     

The scientific impact of the Structural Genomics Consortium: a protein family and ligand-centered approach to medically-relevant human proteins

As many of the structural genomics centers have ended their first phase of operation, it is a good point to evaluate the scientific impact of this endeavour. The Structural Genomics Consortium (SGC), operating from three centers across the Atlantic, investigates human proteins involved in disease processes and proteins from Plasmodium falciparum and related organisms. We present here some of the scientific output of the Oxford node of the SGC, where the target areas include protein kinases, phosphatases, oxidoreductases and other metabolic enzymes, as well as signal transduction proteins. The SGC has aimed to achieve extensive coverage of human gene families with a focus on protein–ligand interactions. The methods employed for effective protein expression, crystallization and structure determination by X-ray crystallography are summarized. In addition to the cumulative impact of accelerated delivery of protein structures, we demonstrate how family coverage, generic screening methodology, and the availability of abundant purified protein samples, allow a level of discovery that is difficult to achieve otherwise. The contribution of NMR to structure determination and protein characterization is discussed. To make this information available to a wide scientific audience, a new tool for disseminating annotated structural information was created that also represents an interactive platform allowing for a continuous update of the annotation by the scientific community.