48,888 research outputs found
Mean sze of the landed catch: a fishery community index for trend assessment in exploited marine ecosystems
Based on fisheries landings data I propose the size-base index (community level) Mean Size of the Landing Catch (MSL). The MSL index was estimated based on high taxonomic resolution data available from auctions (species level) and demographic data acquired during the auction, namely species landed by "size-box" categories, which is assessed mandatorily in all EU members state for fisheries quality and statistic proposes. The MSL was calculated from the average inferred size-box categories of a species weighted by their annual catch. The use of MSL allows determining inter-annual changes in the size of the catch when weighted data is available from the fishery. Using the Portuguese fisheries landing data as an example, the MSL revealed that the landing yield of large fish linearly declined over time while the catch of small fishes increased (i.e., survivors to old age was reduced by fishing). The MSL can be easily used to assess trends in marine exploited commercial communities (community rather than population level) and is fully applicable with any species-size data source (e.g., scientific surveys, visual census data). The MSL can also be applied as a key indicator within the new ecosystem-based Marine Policy Framework Strategy (ecosystem approach to fisheries), which required the use of size-based indicators for the assessment of fisheries trends in exploited marine communities.CLIMFISH project A framework for assess vulnerability of coastal fisheries to climate change in Portuguese coast - Portugal 2020
n2/SAICT/2017 - SAICTinfo:eu-repo/semantics/publishedVersio
Reconstructing discards profiles of unreported catches
In Portugal it has been estimated that unreported catches represent one third of total catches. Herein, information on landings and total unreported catches (discards) by commercial métier were disaggregated into high taxonomic detail using published scientific studies. Fish accounted for 93.5% (115493 t) of overall unreported catches per year, followed by cephalopods (2345 t, 1.9%) and crustaceans (1754 t, 1.4%). Sharks accounted for 1.3% of total unreported catches in weight (1638 t/y). Unreported taxa consisted mostly of the commercial landed fish species: Scomber colias, Boops boops, Trachurus picturatus, T. trachurus, Merluccius merluccius, Sardina pilchardus, Liza aurata and Micromesistius poutassou, which together accounted for 70% of the unreported discarded catches. The number of unreported/discarded species was highest in artisanal fisheries, followed by trawl and purse seine. In artisanal fisheries, L. aurata, S. colias, S. pilchardus, Trachinus draco and B. boops accounted for 76.4% of the unreported discards. B. boops, S. colias and S. pilchardus were also among the most discarded purse seine species, together with Belone belone accounting for 79% of the unreported catches. In trawl fisheries, T. picturatus (16%), M. merluccius (13%), S. colias (13%) and M. poutassou (13%) accounted for 55% of the trawl discarded unreported catches. The discarded species that most contribute to overall unreported catches are those that are most frequently landed and that most contribute to overall landings in weight.SFRH/BD/104209/2014 and SFRH/
BPD/108949/2015). This work received national funds
through the Foundation for Science and Technology
(FCT) through project UID/Multi/04326/2013. Karim
Erzini was supported by funding from the European
Commission’s Horizon 2020 Research and Innovation
Programme under Grant Agreement No. 634495 for
the project Science, Technology, and Society Initiative
to minimize Unwanted Catches in European Fisheries
(MINOUW)info:eu-repo/semantics/publishedVersio
Molecular characterization of Portuguese populations of the pinewood nematode Bursaphelenchus xylophilus using cytochrome b and cellulase genes
Bursaphelenchus xylophilus is the causal agent of pine wilt disease and a
worldwide pest with high economic impact. Since its first diagnosis in Portugal
in 1999, it has been subjected to quarantine measures with impact on forest
health and ecosystem stability, significantly affecting international trade of wood
products. The disease was detected in the north and centre of continental
Portugal and, since 2008, the whole country has been considered an affected
area. Recently, it was detected in Madeira Island. In order to avoid new
outbreaks, it has become of major importance to understand the patterns of
spread, introduction points and to characterize the new populations from
continental Portugal and Madeira Island. Mitochondrial cytochrome b (cytb) and
parasitic cellulase gene sequences were used to evaluate the genetic
relationships among isolates that could indicate possible origins of the new
outbreaks. Portuguese isolates were compared with isolates from USA, China,
Japan and South Korea, in order to investigate possible infection pathways and
disease spread patterns in Portugal. Phylogenetic trees based on both genes
show that Portuguese isolates group with Asian isolates. Isolates from USA are
in a separate position in both gene trees. However, the phylogenetic tree based
on the cellulase gene sequences shows higher differentiation among Portuguese
isolates than that of cytb. These results agree with those previously obtained
using inter-simple sequence repeats (ISSR). This was the first study to use cytb
and cellulase genes to characterize pinewood nematode (PWN) populations.
This study suggests that cellulase is a better marker than cytb to study genetic
diversity in B. xylophilus
How Overfishing Impacts You: The Battle for Ocean Supremacy: The Jellyfish Conquests 1
This briefing published by OCEAN2012 exposes how overfishing impacts on the quality of fish people in Europe are eating. It is part of a series of briefings illustrating the impacts of overfishing on people or marine ecosystems caused by the excess removal of millions of tonnes of marine life every year
Morphological response of the saltmarsh habitats of the Guadiana estuary due to flow regulation and sea-level rise
In the context of rapid sea-level rise in the 21st century, the reduction of fluvial sediment supply due to the regulation of river discharge represents a major challenge for the management of estuarine ecosystems. Therefore, the present study aims to assess the cumulative impacts of the reduction of river discharge and projected sea-level rise on the morphological evolution of the Guadiana estuary during the 21st century. The assessment was based on a set of analytical solutions to simplified equations of tidal wave propagation in shallow waters and empirical knowledge of the system. As methods applied to estimate environmental flows do not take into consideration the fluvial discharge required to maintain saltmarsh habitats and the impact of sea-level rise, simulations were carried out for ten cases in terms of base river flow and sea-level rise so as to understand their sensitivity on the deepening of saltmarsh platforms.Results suggest saltmarsh habitats may not be affected severely in response to lower limit scenarios of sea-level rise and sedimentation. A similar behaviour can be expected even due to the upper limit scenarios until 2050, but with a significant submergence afterwards. In the case of the upper limit scenarios under scrutiny, there was a net erosion of sediment from the estuary. Multiplications of amplitudes of the base flow function by factors 1.5, 2, and 5 result in reduction of the estimated net eroded sediment volume by 25, 40, and 80%, respectively, with respect to the net eroded volume for observed river discharge. The results also indicate that defining the minimum environmental flow as a percentage of dry season flow (as done presently) should be updated to include the full spectrum of natural flows, incorporating temporal variability to better anticipate scenarios of sea-level rise during this century. As permanent submergence of intertidal habitats can be significant after 2050, due to the projected 79 cm rise of sea-level by the year 2100, a multi-dimensional approach should be adopted to mitigate the consequences of sea-level rise and strong flow regulations on the ecosystem of the Guadiana Estuary. (C) 2016 Elsevier Ltd. All rights reserved
Assessment of trace element pollution and its environmental risk to freshwater sediments influenced by anthropogenic contributions: The case study of Alqueva reservoir (Guadiana Basin)
The Guadiana Basin.(SW Iberian Peninsula) is affected by acid mine drainage (AMD), a consequence of ancient mining activities in the Iberian Pyrite Belt (IPB). Consequently, the sedimerits at the Alqueva reservoir (SE Portugal) in the Guadiana Basin are potentially contaminated by trace elements, which make important: (i) to characterize the status of trace element pollution of the sediments; (ii) to evaluate the mobility and the bioavailability of As, Cd, Cu, Cr, Pb and Zn; and (iii) to assess the environmental risk associated with the total and bioavailable concentrations of trace elements, using the sediment quality guidelines (SQGs) and the risk assessment code (RAC). Metal enrichment factors (EF) and geoaccumulation indexes (I-geo), determined taking into account the regional background levels, revealed that, among the metals analyzed, Cd contributed the highest to pollution levels followed by Pb and As. Despite the trace element contamination of the Alqueva sediments, the sequential extraction showed that Most of them are found in the oxidizable and residual fractions, which indicates that they are sparingly bioavailable, with exception of Cd (acid-labile fraction) and Pb (reducible fraction). Based on the RAC, Cd was the only metal that presented a high risk, while Pb, As and Zn showed a medium risk. Moreover, the SQGs revealed the existence of certain areas of extremely high risk, particularly related to high concentrations of total As and, in less extent, of Pb and Cd, associated with AMD, wastewater discharges and runoff of plant protection products from agricultural fields located near the reservoir. (C) 2015 Elsevier By. All rights reserved.FCT (Fundacao para a Ciencia e Tecnologia) [PTDC/AAC-AMB/103547/2008]; FEDER, through POFC (Eixo I - Programa Operacional Fatores de Competitividade) from QREN [COMPETE Re: FCOMP-01-0124-FEDER-008582]info:eu-repo/semantics/publishedVersio
Anisakis infection in allis shad, Alosa alosa (Linnaeus, 1758), and twaite shad, Alosa fallax (Lacépède, 1803), from Western Iberian Peninsula Rivers : zoonotic and ecological implications
Acknowledgments The authors would like to thank M. N. Cueto and J.M. Antonio (ECOBIOMAR) for their excellent technical support and also Rodrigo López for making the map of the study area. We also thank the personal of the Vigo IEO, for providing information about shad captures at sea collected on the basis of national program (AMDES) included in the European Data Collection Framework (DCF) project. We are also grateful to Comandancia Naval de Tui for providing fishing data. M. Bao is supported by a PhD grant from the University of Aberdeen and also by financial support of the contract from the EU Project PARASITE (grant number 312068). This study was partially supported by a PhD grant from the Portuguese Foundation for Science and Technology (FCT) SFRH/BD/44892/2008) and partially supported by the European Regional Development Fund (ERDF) through the COMPETE—Operational Competitiveness Programme and national funds through Foundation for Science and Technology (FCT), under the project BPEst-C/MAR/ LA0015/2013. The authors thank the staff of the Station of Hydrobiology of the USC BEncoro do Con^ due their participation in the surveys. This work has been partially supported by the project 10PXIB2111059PR of the Xunta de Galicia and the project MIGRANET of the Interreg IV BSUDOE (South-West Europe) Territorial Cooperation Programme (SOE2/P2/E288). D.J. Nachón is supported by a PhD grant from the Xunta de Galicia (PRE/2011/198)Peer reviewedPostprin
Narrative Fortresses: Crisis Narratives And Conflict In The Conservation Of Mount Gorongosa, Mozambique
A single narrative about the Gorongosa Restoration Project (GRP) in Mozambique circulates widely in the popular media. This story characterises the project as an innovative intervention into an ecological crisis situation. The narrative hails the project\u27s aim to use profits from tourism to address the goals of both human development and conservation of biodiversity, and portrays the park project as widely embraced by long-term residents. This representation helps the project attract broad acclaim, donor funding, and socially conscious visitors, yet it obscures the early emergence of unified opposition to the project\u27s interventions among long-term residents of Gorongosa Mountain. This article draws on ethnographic research conducted on Gorongosa Mountain between 2006 and 2008 to examine the project\u27s early activities there. I examine two crisis narratives that led to entrenched conflict between park-based actors and mountain residents. Focusing on the emergence and solidification of divergent narratives-narrative fortresses-about the extension of the park\u27s activities to Gorongosa Mountain offers insight into the powerful role of crisis narratives in producing and maintaining conflict, leading to outcomes counter to the desires of conservationists. Ultimately, the article points to ways in which narratives of environmental crisis work against aspirations of partnership and collaboration with resident populations in conservation and development schemes
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