Search results for " Fishery"
showing 10 items of 43 documents
Individual habitat transitions of Atlantic herring Clupea harengus in a human-modified coastal system
2015
Published version of an article from the journal: Marine Ecology Progress Series. Also available from Inter Research. Http://dx.doi.org/10.3354/meps11103 Pelagic marine fish often display highly dynamic migration patterns. However, such movement behaviour is usually studied at the population or school level, while less is known about individual movement characteristics and habitat transitions. During March 2012 to June 2013, we used acoustic tags and moored receivers to monitor the behaviour of Atlantic herring Clupea harengus L. (N = 47) throughout a range of habitats on the Skagerrak coast in southern Norway. Five of the tagged herring entered a former lake transformed into an artificial …
Sustainable development since the 2004 tsunami : a glimse into the fisheries of Hambantota district, Sri Lanka
2013
Master thesis in development management - University of Agder 2013 Fish is an important source of protein for many of the world’s population. For fish resources to be renewable marine aquatic ecosystems must be protected. This view is not held by all of those directly involved in fisheries. How those involved in fisheries are aware of and work in relation to notions of the importance of conservation of natural resources plays a role in illustrating how sustainable the fishery they work in actually is. The case of Hambantota district fisheries in Sri Lanka was chosen to investigate this element of sustainable relations between humans and natural resources. This research has acquired informat…
Adaptation to Low Salinity Promotes Genomic Divergence in Atlantic Cod (Gadus morhua L.)
2015
Published version of an article from the journal:Genome Biology and Evolution. Available from the publisher: http.//dx.doi.org/1093/gbe/evv093 How genomic selection enables species to adapt to divergent environments is a fundamental question in ecology and evolution. We investigated the genomic signatures of local adaptation in Atlantic cod (Gadus morhua L.) along a natural salinity gradient, ranging from 35% in the North Sea to 7% within the Baltic Sea. By utilizing a 12 K SNPchip, we simultaneously assessed neutral and adaptive genetic divergence across the Atlantic cod genome. Combining outlier analyses with a landscape genomic approach, we identified a set of directionally selected loci…
Movement patterns of temperate wrasses (Labridae) within a small marine protected area
2021
The movement patterns of three commercially important wrasse (Labridae) species inside a small marine protected area (~ 0.15 km2 ) on the west coast of Norway were analysed over a period of 21 months. The mean distance between capture and recapture locations varied between 10 and 187 m, and was species and season specific. The extent of movement was not related to body size or sex. These results imply that a network of small strategically located marine protected areas can be used as management tools to protect wrasses from size- and sex-selective fishing mortality.
Isolation and characterization of twenty microsatellite loci for the ballan wrasse, Labrus bergylta
2014
Published version of an article in the journal: Conservation Genetics Resources. Also available from the publisher at: http://dx.doi.org/10.1007/s12686-013-0114-3 Open Access We developed 20 nuclear microsatellite DNA markers from tri- and tetra-nucleotide enriched libraries in the ballan wrasse. In our dataset (N = 241), the detected number of alleles per locus ranged from 2 to 12, and the observed and expected heterozygosity varied from 0.251 to 0.778 and from 0.286 to 0.804, respectively. Cross amplification with the goldsinny wrasse resulted in two usable loci whereas the corkwing wrasse amplified in one locus. The ballan wrasse is an important resource for aquaculture as it delouses fa…
Illegal Chinese gold mining in Amansie West, Ghana - an assessement of its impact and implications
2014
Master thesis in development management - University of Agder 2014 The thesis’ objective is to assess the impact of Chinese illegal miners in the Amansie West District in Ghana. The illegal mining sector is seen as having several negative effects, environmentally as well as socially and economically. The influx of some 20-50 000 Chinese miners into Ghana is found to increase these impacts. The Chinese illegal miners operate largely on farmland, which is bought from locals for the sum equivalent of approximately 6.5 years of farming income. This leads to a loss of long-term income for the farmer as well as the degradation of large land areas, which in the case of Amansie West is here estimat…
Implementing ecosystem approach to fishery management: advances and new tools
2013
Desde la antigüedad, la pesca ha sido una fuente importante de alimentos para la humanidad, así como fuente de empleo y beneficios económicos para quienes se dedican a esta actividad. Sin embargo, con el aumento de los conocimientos científicos y la evolución dinámica de la pesca se hizo evidente de que los recursos acuáticos, aunque renovables, no eran infinitos y era necesario gestionar adecuadamente su contribución al bienestar nutricional, económico y el bienestar social de la población mundial para un crecimiento y desarrollo sostenible. En los últimos años, la pesca mundial se ha convertido en un sector dinámico y de desarrollo de la industria alimentaria. Los estados costeros han pro…
From sustainability to sustainable development: the role of food banks in food security in Uganda : a case study of the hunger project food bank - Mb…
2014
Master thesis in development management - University of Agder 2014 The purpose of this study is to identify the role the food bank plays for food security, sustainable livelihoods and building resilience to climate change among smallholder farmers in Uganda. The aim is to investigate how the food bank in Uganda operates in relation to food security and smallholder farmers. Much of the studies on food banks reveal that food banks are merely institutions that offer emergency food supplies to the hungry and are not agencies aiming at food security. These studies have, however, been based on the context of developed countries and no study has been conducted to establish the role of food banks i…
Simulated eutrophication and browning alters zooplankton nutritional quality and determines juvenile fish growth and survival
2018
Source at https://doi.org/10.1002/ece3.3832. The first few months of life is the most vulnerable period for fish and their optimal hatching time with zooplankton prey is favored by natural selection. Traditionally, however, prey abundance (i.e., zooplankton density) has been considered important, whereas prey nutritional composition has been largely neglected in natural settings. High‐quality zooplankton, rich in both essential amino acids (EAAs) and fatty acids (FAs), are required as starting prey to initiate development and fast juvenile growth. Prey quality is dependent on environmental conditions, and, for example, eutrophication and browning are two major factors defining primary produ…
Long-term decrease in sex-specific natural mortality of European lobster within a marine protected area
2013
Marine protected areas (MPAs) and marine reserves hold promise as tools for nature conservation and fisheries management, but data on long-term demographic effects are still sparse. Here, we use a unique capture-mark-recapture data set from Kavra, an MPA on the west coast of Sweden where fishing for European lobster Homarus gammarus has been banned since 1989, to directly quantify annual survival probabilities in the absence of harvest mortality. The non-migratory behaviour of this species allowed multiple recaptures and releases of a large num- ber of individuals within the MPA. We found strong evidence for a long-term decrease in sex - specific natural mortality throughout the study perio…