Search results for "MACRO"
showing 10 items of 3471 documents
Jellyfish Impacts on Marine Aquaculture and Fisheries
2020
Over the last 50 years, there has been an increased frequency and severity of negative impacts affecting marine fishery and aquaculture sectors, which claimed significant economic losses due to the interference of stinging gelatinous organisms with daily operational activities. Nevertheless, original scientific information on jellyfish-related incidents, their consequences, and potential preventative and mitigation countermeasures is limited and scattered across gray literature, governmental technical reports, and communication media. A literature scan searching for records of any interactions between jellyfish and the marine fishery/aquaculture sectors were carried out. Out of 553 papers, …
Predicting and testing functional responses: An example from a tardigrade–nematode system
2008
Abstract Numerous studies have empirically measured consumer functional responses or theoretically developed response models, but whether these models can quantitatively predict observed data has hardly been tested. We perform such a test for the terrestrial predator–prey system Macrobiotus richtersi (Tardigrada)– Acrobeloides nanus (Nematoda). For two different size classes of A. nanus , we report a functional response as measured in the laboratory and quantitatively compare it to predictions of three models with different degrees of complexity: (1) the disc equation which does not include satiation effects; (2) the steady-state satiation (SSS) equation which assumes a constant level of pr…
Genetic homogeneity in the deep-sea grenadier Macrourus berglax across the North Atlantic Ocean
2018
Paucity of data on population structure and connectivity in deep sea species remains a major obstacle to their sustainable management and conservation in the face of ever increasing fisheries pressure and other forms of impacts on deep sea ecosystems. The roughhead grenadier Macrourus berglax presents all the classical characteristics of a deep sea species, such as slow growth and low fecundity, which make them particularly vulnerable to anthropogenic impact, due to their low resilience to change. In this study, the population structure of the roughhead grenadier is investigated throughout its geographic distribution using two sets of molecular markers: a partial sequence of the Control Reg…
Do carotenoid-based sexual traits signal the availability of non-pigmentary antioxidants?
2006
SUMMARY Carotenoid-based signals are thought to be indicators of male quality because they must be obtained from the diet and might thus indicate the ability of individuals to gather high-quality food. However, carotenoids are also known to have important physiological functions as immunoenhancers and antioxidants, and, as such, carotenoid-based sexual traits have also been suggested to reflect the health and antioxidant status of their bearers. This last idea is based on the hypothesis that carotenoids that are allocated to sexual signals are no longer available for the detoxification system. Recently, this hypothesis has been challenged on the grounds that the antioxidant activity is not …
Differences in the growth cycle ofRuppia cirrhosa(Petagna) Grande in a Mediterranean shallow system
2014
Ruppia cirrhosa growth cycle was analysed in a southern Mediterranean shallow system throughout 1 year. We examined the temporal variation in R. cirrhosa cover percentage, shoot density, biomass, leaf length, no. flowers m-2 and no. fruits m-2 in two groups of pond characterized by differences in some environmental parameters. Ponds were comparable for salinity and temperature but they differed for other environmental parameters such as water depth, level of suspended organic matter and chlorophyll a (CHL a). Biological parameter values were higher in B ponds, characterized by lower values of water depth, suspended organic matter and CHL a. A seasonal trend for all considered biological par…
Structuring factors of the spatio-temporal variability of macrozoobenthos assemblages in a southern Mediterranean lagoon: How useful for bioindicatio…
2017
International audience; The authors investigated the impact of the extension of the El Kantra Channel on the composition and structure of macrobenthic assemblages in Boughrara Lagoon (Gulf of Gabes, Tunisia along with the use of 4 biotic indices (AMBI, BENTIX, M-AMBI and TUBI). Thirteen stations were sampled seasonally in 2012–2013. Forty-one species were found in 2012–2013 not recorded in 2009–2010, including 20 species of polychaetes belonging to the trophic groups of deposit-feeders and carnivores which are expected to increase in areas disturbed by organic pollution. During the survey, we recorded a high fish mortality, essentially caused by the development of harmful algal blooms (HAB)…
Reproductive phenology of submerged macrophytes: A tracker of year‐to‐year environmental variations
2019
AIMS: Phenological shifts are useful trackers of climate change effects on species and communities, but few datasets focus on the climate‐driven phenological responses of aquatic ecosystem vegetation. We aimed to analyse the reproductive seasonality of a submerged macrophyte community, the synchrony among coexisting species, and their responses to several environmental factors. LOCATION: A Mediterranean coastal pond in Valencia, Spain. METHODS: We analysed three years of data on a submerged macrophyte community. Plants were collected biweekly or monthly (57 collection dates) to quantify the intensity of flowering/fruiting per species. The reproductive seasonality of the community was tested…
Assessment of surface sediment dynamics and response of benthic macrofauna assemblages in Boughrara Lagoon (SW Mediterranean Sea)
2016
International audience; A study was conducted in the spring of 2009, the winters of 2010 and 2013, and in the summer of 2012 at 13 stations in Boughrara Lagoon, Tunisia (southern Mediterranean). The country’s largest lagoon, it is considered to be an anthropogenically stressed area, though a major tourist centre—Djerba Island—is located along its northern shores. The lagoon bottoms were studied via analyses of grain size, surface sediment composition, total organic matter (TOM) and through the trophic and functional organisation of benthic macrofauna. The results indicate that the bottoms are composed of fine, medium or coarse sands and that sediment distribution is controlled by water move…
Circummed pine forest database: An electronic archive for mediterranean and submediterranean pine forest vegetation data
2019
Large thematic databases of vegetation plots are increasingly needed for vegetation studies and biodiversity research. In this paper, we present the CircumMed Pine Forest Database (GIVD ID: EU-00-026), which in November 2018, comprised records from 6317 pine-dominated vegetation plots (relevés) and associated vegetation types from 20 countries of the Mediterranean Basin, Near East and Crimea. These vegetation plots were collected through a detailed literature search for plots not previously included in the European Vegetation Archive (EVA), in order to fill geographic gaps in data coverage. The database comprises Mediterranean (including Oromediterranean) pine-forest vegetation plots from b…
First successful eradication of invasive Norway rats Rattus norvegicus from a small Mediterranean island (Isola delle Femmine, Italy)
2019
Invasive alien species, once introduced, may affect local biodiversity, both directly (e.g. by predation) and indirectly (e.g. by reducing the vegetation cover). Among those, rats (Rodentia, Muridae) are listed among the most invasive species, exerting strong impacts particularly when introduced to island ecosystems. Accordingly, black rats Rattus rattus have been eradicated from a number of islands in the Mediterranean basin to protect breeding seabirds. Where the larger Norway rat Rattus norvegicus is present, extent of damage may be even higher. In our work, we present the results of the first eradication program dealing with Norway rats in a small Mediterranean island (Isola delle Femmi…