7 resultados para marine protected networks
em Archimer: Archive de l'Institut francais de recherche pour l'exploitation de la mer
Resumo:
A better understanding of the key ecological processes of marine organisms is fundamental to improving design and effective implementation of marine protected areas (MPAs) and marine biodiversity. The movement behavior of coral reef fish is a complex mechanism that is highly linked to species life-history traits, predation risk and food resources. We used passive acoustic telemetry to study monthly, daily and hourly movement patterns and space use in two species, Schoolmaster snapper (Lutjanus apodus) and Stoplight parrotfish (Sparisoma viride). We investigated the spatial overlap between the two species and compared intra-specific spatial overlap between day and night. Presence-absence models showed different diel presence and habitat use patterns between the two species. We constructed a spatial network of the movement patterns, which showed that for both species when fish were detected by the array of receivers most movements were made around the coral reef habitat while occasionally moving to silt habitats. Our results show that most individuals made predictable daily crepuscular migrations between different locations and habitat types, although individual behavioral changes were observed for some individuals across time. Our study also highlights the necessity to consider multiple species during MPA implementation and to take into account the specific biological and ecological traits of each species. The low number of fish detected within the receiver array, as well as the intraspecific variability observed in this study, highlight the need to compare results across species and individuals to be used for MPA management.
Resumo:
Well-designed marine protected area (MPA) networks can deliver a range of ecological, economic and social benefits, and so a great deal of research has focused on developing spatial conservation prioritization tools to help identify important areas. However, whilst these software tools are designed to identify MPA networks that both represent biodiversity and minimize impacts on stakeholders, they do not consider complex ecological processes. Thus, it is difficult to determine the impacts that proposed MPAs could have on marine ecosystem health, fisheries and fisheries sustainability. Using the eastern English Channel as a case study, this paper explores an approach to address these issues by identifying a series of MPA networks using the Marxan and Marxan with Zones conservation planning software and linking them with a spatially explicit ecosystem model developed in Ecopath with Ecosim. We then use these to investigate potential trade-offs associated with adopting different MPA management strategies. Limited-take MPAs, which restrict the use of some fishing gears, could have positive benefits for conservation and fisheries in the eastern English Channel, even though they generally receive far less attention in research on MPA network design. Our findings, however, also clearly indicate that no-take MPAs should form an integral component of proposed MPA networks in the eastern English Channel, as they not only result in substantial increases in ecosystem biomass, fisheries catches and the biomass of commercially valuable target species, but are fundamental to maintaining the sustainability of the fisheries. Synthesis and applications. Using the existing software tools Marxan with Zones and Ecopath with Ecosim in combination provides a powerful policy-screening approach. This could help inform marine spatial planning by identifying potential conflicts and by designing new regulations that better balance conservation objectives and stakeholder interests. In addition, it highlights that appropriate combinations of no-take and limited-take marine protected areas might be the most effective when making trade-offs between long-term ecological benefits and short-term political acceptability.
Resumo:
Current dynamics in the Strait of Bonifacio (south Corsica) were investigated at a small scale during the STELLAMARE1 multidisciplinary cruise in summer 2012, using in situ measurements and modeling data. The Strait of Bonifacio is a particularly sensitive marine area in which specific conservation measures have been taken to preserve the natural environment and wild species. Good knowledge of the hydrodynamics in this area is essential to optimize the Marine Protected Area's management rules. Therefore, we used a high-resolution model (400 m) based on the MARS3D code to investigate the main flux exchanges and to formulate certain hypotheses about the formation of possible eddy structures. The aim of the present paper is first to synthetize the results obtained by combining Acoustic Doppler Current Profiler data, hydrological parameters, Lagrangian drifter data, and satellite observations such as MODIS OC5 chlorophyll a data or Metop-A AVHRR Sea Surface Temperature (SST) data. These elements are then used to validate the presence of the mesoscale eddies simulated by the model and their recurrence outside the cruise period. To complete the analysis, the response of the 3D hydrodynamical model was evaluated under two opposing wind systems and certain biases were detected. Strong velocities up to 1 m s(-1) were recorded in the east part due to the Venturi effect; a complementary system of vortices governed by Coriolis effect and west wind was observed in the west part, and horizontal stratification in the central part has been identified under typical wind condition.
Resumo:
To determine good ecological status and conservation of the Sub-Marine area of the Bay of Biscay, the implementation of a new rocky intertidal habitats monitoring is needed. A protocol has been adapted from the Brittany protocol for the water body FRFC11 "Basque coast" for the two indicators "intertidal macroalgae" and "subtidal macroalgae" under the Water Framework Directive to qualify the ecological. However no protocol has been validated for fauna in front of meridional characters of the benthic communities. Investigations carried out on macroalgae communities on intertidal area in WFD framework, since 2008, constitute an important working basis. This is the aim of the Bigorno project (Intertidal Biodiversity of the south of the Bay of Biscay and Observation for New search and Monitoring for decision support), financed by the Agency of Marine Protected Areas and the Departmental Council. To implement knowledge, a sampling protocol has been used in 2015 on the boulder fields of Guéthary. This site is part of Natura 2000 area "rocky Basque coast and offshore extension "It constitutes also a Znieff site and restricted fishing area. The sampling strategy considers the heterogeneity of substrates and the presence of intertidal microhabitats. Two main habitats are present: "mediolittoral rock in exposed area habitat" and "boulder fields". Habitat "intertidal pools and permanent ponds" is also present but, it is not investigated. Sampling effort is of 353 quadrats of 0.1 m², drawn randomly according to a spatially stratified sampling plan, defined by habitat and algal belts. Taxa identification and enumeration are done on each quadrat. The objective of this work is to expose results from data collected during 2015 sampling program. The importance of characterizing benthic fauna communities spatial distribution belonging to the Basque coast according to algal belts defines during the WDF survey was highlighted. Concurrently, indicators of biodiversity were studied.
Resumo:
The rocky Basque coast presents an interest both in terms of biogeography and its patrimonial situation, alongside its habitats, fauna and flora. The aim of the BIGORNO project (Intertidal Biodiversity of the south of the Bay of Biscay and Observation for New research and Monitoring for decision support), financed by the Agency of Marine Protected Areas (AAMP) and the Departmental Council (CD 64), is to respond to significant deficiencies on biocenosis in the southern marine subregion “Bay of Biscay”. Investigations carried out in the WFD, since 2008, constitute an important basis of work for integration of fauna. Field studies undertaken since 2015 consisting of a sampling design suited to the substrates heterogeneity and the presence of microhabitats were established on an intertidal area specifically on a "Boulder fields" habitat. Assessment was undertaken by sampling quadrats of 0.1 m² drawn randomly from a spatially stratified sampling plan. Our study aims for a better understanding of stratification of this habitat and allowed us to highligh tindicator taxa of the "Boulder fields" habitat. Functions included in the package indicspecies (CRAN) were used to conduct indicator species analysis and to assess the significance of the relationship between taxa or taxa combinations and the habitat. It is therefore possible to describe some species or species groups which are specific to boulder fields through the assessment of their functional traits and local biodiversity. These various analyses allow for a sustainable way of monitoring the Basque intertidal rocky shore.
Resumo:
1.This report presents the results of a field study conducted in the ECASA test site nOS in the Pertuis Breton, France. The site is located on the Atlantic West coasts. It is open to the bay of Biscay, but is slightly protected against westerly winds. The bay has been exploited by intertidal mussels culture for centuries. 2. Within the bay, mussels (Mytilus edulis) are cultivated either by the traditional pole technique, around the bay or on longlines in the centre of the bay. The area occupied by these longline s represents 250 ha, and the resulting annual production is 1 000 tonnes of mussels. The average depth at mid tide is of 13.8 m. The sediment is sandy, with a small fraction of mud. 3. The site is subject to several regular monitoring through the local implementation of national networks aiming at protecting the environment and marine resources, on pollutants (RNO), microbiological quality of the waters (REMI), phytoplanktonic toxic species (REPHY) and growth and mortality of molluscs (REMORA). Benthic macrofauna was studied in 1976. 4. Five sampling sations were chosen along a line, starting under the longlines, and at distances of 50, 100, 200, and 400 metres from the area cultivated. A reference station was chosen in a different direction at 2300 metres of the cultivated area. Sampling methods are described in the text. _Sediments were sampled for different analyses: grain size, content in organic matter, total organic carbon and nitrogen, and phytic pigments (chlorophyll a and phaeopigments). Redox were measured in cores. The macrofauna living into the sediment was also sampled. The water column was sampled for physical (temperature, transparency) and chemical parametres, including oxygen content, salinity, organic matter, dissolved nitrogen forms, phosphates and silicates. Results from benthic macrofauna surveys indicate that there were no significant differences between the different stations and the reference station, all being classified as slightly disturbed. The bay is submitted to freshwater runoffs from two adjacent rivers. 7. The sediment is slightly modified by the culture of bivalves. Total organic carbon, total nitrogen, Eh values and pheopigments were significantly higher under the trestles than in any other stations. Other stations often did not differ from the reference station. 8. The effects of shellfish culture on the water column were. However, it was observed a small decrease of the food available to the molluscs near the rearing 9. The DEB model was able to describe and predict adequately the growth of oysters, both in the Baie des Veys and in the Loch Creran. The parametres for its use in other environment are given, but a tuning of one parametre should be performed with the help of authors. 10. Among the indicators and models for use in are as of intertidal bivalve culture, it is recommended to use the sediment quality index, TOC (Total Organic Carbon), redox and pheopigments, in surficial sediment, AMBI for the macrofauna, chlorophyll a contents and nitrogen forms in the water column, and models describing the carrying capacity, filtration rate of molluscs, and a DEB model to predict the growth of molluscs.
Resumo:
Over the past several decades, thousands of otoliths, bivalve shells, and scales have been collected for the purposes of age determination and remain archived in European and North American fisheries laboratories. Advances in digital imaging and computer software combined with techniques developed by tree-ring scientists provide a means by which to extract additional levels of information in these calcified structures and generate annually resolved (one value per year), multidecadal time-series of population-level growth anomalies. Chemical and isotopic properties may also be extracted to provide additional information regarding the environmental conditions these organisms experienced.Given that they are exactly placed in time, chronologies can be directly compared to instrumental climate records, chronologies from other regions or species, or time-seriesof other biological phenomena. In this way, chronologies may be used to reconstruct historical ranges of environmental variability, identify climatic drivers of growth, establish linkages within and among species, and generate ecosystem-level indicators. Following the first workshop in Hamburg, Germany, in December 2014, the second workshop on Growth increment Chronologies in Marine Fish: climate-ecosystem interactions in the North Atlantic (WKGIC2) met at the Mediterranean Institute for Advanced Studies headquarters in Esporles, Spain, on 18–22 April 2016, chaired by Bryan Black (USA) and Christoph Stransky (Germany).Thirty-six participants from fifteen different countries attended. Objectives were to i) review the applications of chronologies developed from growth-increment widths in the hard parts (otoliths, shells, scales) of marine fish and bivalve species ii) review the fundamentals of crossdating and chronology development, iii) discuss assumptions and limitations of these approaches, iv) measure otolith growth-increment widths in image analysis software, v) learn software to statistically check increment dating accuracy, vi) generate a growth increment chronology and relate it to climate indices, and vii) initiate cooperative projects or training exercises to commence after the workshop.The workshop began with an overview of tree-ring techniques of chronology development, including a hands-on exercise in cross dating. Next, we discussed the applications of fish and bivalve biochronologies and the range of issues that could be addressed. We then reviewed key assumptions and limitations, especially those associated with short-lived species for which there are numerous and extensive otolith archives in European fisheries labs. Next, participants were provided with images of European plaice otoliths from the North Sea and taught to measure increment widths in image analysis software. Upon completion of measurements, techniques of chronology development were discussed and contrasted to those that have been applied for long-lived species. Plaice growth time-series were then related to environmental variability using the KNMI Climate Explorer. Finally, potential future collaborations and funding opportunities were discussed, and there was a clear desire to meet again to compare various statistical techniques for chronology development using a range existing fish, bivalve, and tree growth-increment datasets. Overall, we hope to increase the use of these techniques, and over the long term, develop networks of biochronologies for integrative analyses of ecosystem functioning and relationships to long-term climate variability and fishing pressure.