Search results for " technology"

The "Tracked Roaming Transect" and distance sampling methods increase the efficiency of underwater visual censuses.

2018

Underwater visual census (UVC) is the most common approach for estimating diversity, abundance and size of reef fishes in shallow and clear waters. Abundance estimation through UVC is particularly problematic in species occurring at low densities and/or highly aggregated because of their high variability at both spatial and temporal scales. The statistical power of experiments involving UVC techniques may be increased by augmenting the number of replicates or the area surveyed. In this work we present and test the efficiency of an UVC method based on diver towed GPS, the Tracked Roaming Transect (TRT), designed to maximize transect length (and thus the surveyed area) with respect to diving …

2020

Marine and coastal activities are closely interrelated, and conflicts among different sectors can undermine management and conservation objectives. Governance systems for fisheries, power generation, irrigation, aquaculture, marine biodiversity conservation, and other coastal and maritime activities are typically organized to manage conflicts within sectors, rather than across them. Based on the discussions around eight case studies presented at a workshop held in Brest in June 2019, this paper explores institutional approaches to move beyond managing conflicts within a sector. We primarily focus on cases where the groups and sectors involved are heterogeneous in terms of: the jurisdiction …

Genome Sequencing and Transcriptome Analysis Reveal Recent Species-Specific Gene Duplications in the Plastic Gilthead Sea Bream (Sparus aurata)

2019

Gilthead sea bream is an economically important fish species that is remarkably well-adapted to farming and changing environments. Understanding the genomic basis of this plasticity will serve to orientate domestication and selective breeding toward more robust and efficient fish. To address this goal, a draft genome assembly was reconstructed combining short- and long-read high-throughput sequencing with genetic linkage maps. The assembled unmasked genome spans 1.24 Gb of an expected 1.59 Gb genome size with 932 scaffolds (~732 Mb) anchored to 24 chromosomes that are available as a karyotype browser at www.nutrigroup-iats.org/seabreamdb. Homology-based functional annotation, supported by R…

Research priorities for freshwater mussel conservation assessment

2018

Freshwater mussels are declining globally, and effective conservation requires prioritizing research and actions to identify and mitigate threats impacting mussel species. Conservation priorities vary widely, ranging from preventing imminent extinction to maintaining abundant populations. Here, we develop a portfolio of priority research topics for freshwater mussel conservation assessment. To address these topics, we group research priorities into two categories: intrinsic or extrinsic factors. Intrinsic factors are indicators of organismal or population status, while extrinsic factors encompass environmental variables and threats. An understanding of intrinsic factors is useful in monitor…

The Importance of Engaging Local People in Landscape Management – Experiences from an EU Project

2018

“Bull by the Horns” -project initiated landscape management and promoted biodiversity associated with diminishing High Nature Value farmland habitats in Finland. A specific focus was on grazed semi-natural grasslands and wood-pastures which are collectively referred to as traditional rural biotopes (TRBs). Collaboration among project workers, non-farming landowners, and cattle owners reintroduced grazing to abandoned pastures, and management was financed through agri-environmental payments. Using adaptive co-management principles, the project enabled collective definition of integrated site-specific management objectives. A better understanding of contemporary challenges and opportunities t…

Impact of Freshwater Inflow From the Volturno River on Coastal Circulation

2020

The coastal area located in front of the Volturno river's estuary (Gulf of Gaeta, central-eastern Tyrrhenian Sea) has been synoptically sampled during seven surveys, between June 2012 and October 2014. The vertical profiles of temperature and salinity have been acquired on a high resolution nearly-regular grid, in order to describe the spatial and temporal variability of the water masses characteristics. Moreover, to provide a first assessment of the steady circulation at small scale, the three-dimensional velocity field associated to each survey has been obtained through the full momentum equations of the Princeton Ocean Model. The data analysis has shown the entire water column characteri…

Influence of Riverine Input on Norwegian Coastal Systems

2020

Coastal ecosystems are of high ecological and socioeconomic importance and are strongly influenced by processes from land, sea, and human activities. In this study, we present physical, chemical, and biological observations over two consecutive years from three study regions along the Norwegian coast that represent a broad latitudinal gradient in catchment and oceanographic conditions (∼59–69°N): outer Oslofjord/southern Norway, Runde/western Norway, and Malangen/northern Norway. The observations included river monitoring, coastal monitoring, and sensor-equipped ships of opportunity (“FerryBox”). The riverine discharge and transports were an order of magnitude higher, and the spatiotemporal…

An air-lift biofilm reactor for the production of γ-decalactones by Yarrowia lipolytica

2014

Decalactones are interesting flavouring compounds that can be produced from ricinoleic acid. In this study, the production of lactones in biofilms using Yarrowia lipolytica is investigated. The hydrophobia of cells increased for increased aeration rates resulting in higher adhesion when the reactor wall was hydrophobic (plastic). To increase adhesion, sheets of methyl-polymethacrylate (PMMA) were added in the reactor and the production of lactones increased with the surface of plastic added, reaching 850 mg/L of 3-hydroxy-γ-decalactone for 60 cm2. In an Airlift bioreactor made of PMMA, biofilms were present at the top of the reactor for increased aeration. In the meantime, a metabolic shift…

Production of 3-hydroxy-γ-decalactone, the precursor of two decenolides with flavouring properties, by the yeast Yarrowia lipolytica

2009

3-Hydroxy-γ-decalactone is the precursor of dec-2 and dec-3-en-4-olides which are valuable aroma compounds not yet produced. To promote the accumulation of this lactone, the yeast Yarrowia lipolytica was placed in different environmental conditions aiming at altering β-oxidation fluxes. The concentration of substrate, pH, aeration and dissolved oxygen level were modified. We observed an important accumulation at low aeration (0.40 molar yields) and, to a lesser extent, at lower pH (0.15). As oxygen played a key-role, we evaluated its effect at fixed dissolved oxygen and at the pH which was the most favourable to the biotransformation (pH 4.5). At 5% and 30% dissolved oxygen, yields reached …

The effect of low frequency noise on the behaviour of juvenile Sparus aurata.

2020

[EN] Anthropogenic activities are causing increased noise levels in the marine environment. To date, few studies have been undertaken to investigate the effects of different noise frequencies on the behaviour of juvenile fish. In this study, the behavioural changes of juvenile gilthead seabream (Sparus aurata) are evaluated when exposed to white noise filtered in third-octave bands centred at 63, 125, 500, and 1000 Hz (sound pressure level, 140-150 dB re 1 mu& x3a1;a) for 7 h. The group dispersion, motility, and swimming height of the fish were analysed before and during the acoustic emission. Dispersion of the fish was found to reduce immediately upon application of low frequency sound (63…