• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 20
  • 9
  • 6
  • 5
  • 4
  • 1
  • 1
  • Tagged with
  • 58
  • 58
  • 58
  • 22
  • 20
  • 12
  • 9
  • 9
  • 9
  • 8
  • 8
  • 7
  • 7
  • 7
  • 6
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

The Response of a Predatory Fish, Ophiodon elongatus, to a Marine Protected Area: Variation in Diet, Catch Rates, and Size Composition

Anderson, Eric S 01 December 2016 (has links)
Marine Protected Areas (MPAs) are a management tool used to protect and sustain many ecologically and economically important fish species from overexploitation by recreational and commercial fishing. Lingcod (Ophiodon elongatus) and some of its prey species, such as rockfish (Sebastes spp.), are species that are protected from fishing in some California MPAs. Lingcod is an apex predator that consumes a variety of fish and invertebrate species. In this study, I sought to assess the effect of an MPA on the abundance, size and diet of Lingcod. I hypothesized that Lingcod in a no-take MPA would be more abundant and larger than Lingcod in an adjacent reference site (REF) that was open to fishing. Furthermore, I hypothesized that diet would differ between Lingcod in caught the MPA and Lingcod in the REF. I collected Lingcod from the Point Buchon State Marine Reserve (MPA) and an adjacent REF site that was open to fishing. I measured, weighed, sexed, and collected stomach contents from Lingcod using the gastric lavage (stomach pumping) technique. Then, I identified prey items from Lingcod stomach contents down to the lowest taxonomic level possible and quantified diet composition by percent by occurrence, percent by number, and percent by mass. Lingcod in the MPA consumed more fish prey items than Lingcod in the REF site. Lingcod in the REF consumed more cephalopod prey items than Lingcod in the MPA. I analyzed the four most common prey items (rockfish, anchovies, flatfish, and octopus) for nutritional content. My data suggest that Lingcod increased in size and abundance in a no-take MPA because they do not suffer from fishing mortality. However, a more nutritious diet could also contribute to a biologically significant advantage for Lingcod in the MPA. To address this would require further research focused on calculating the net energy (gross energy extracted from the prey item minus the energetic costs of handling and digesting the prey item) obtained by Lingcod from consuming different fish and cephalopod prey items. MPAs can be an effective management tool for protecting fish stocks, although, it is important to understand the interspecific interactions between predator and prey species to adaptively mange MPAs and the species that reside within them.
22

Comparisons of Fish Species Inside and Outside of Marine Protected Areas off the South Central Coast of California

Rasmussen, David E 01 October 2010 (has links) (PDF)
COMPARISONS OF FISH SPECIES INSIDE AND OUTSIDE OF MARINE PROTECTED AREAS OFF THE SOUTH CENTRAL COAST OF CALIFORNIA David E. Rasmussen From 2004-2008 and 2008-2009 Cal Poly University researchers conducted two separate tag and recapture studies of nearshore fish populations along California’s central coast. Three locations were sampled that have experienced different degrees of fishing pressure. Big Creek MPA has been closed to all fishing from 1993 onwards and is the farthest from port of all locations. Cambria lies closest to port of the three locations and because of this has the highest fishing pressure. Piedras Blancas lies midway between Cambria and Big Creek. Portions of Cambria and Piedras Blancas were designated as MPAs in 2007. Sampling protocols of these two different studies differed in bait used and size of commercial fish trap. An experiment was conducted to simultaneously compare the different trapping and baiting protocols from the prior studies to find a conversion factor that related catch per unit effort (CPUE), length frequency distributions and captured fish diversity between the two studies, thus providing a means to connect the two data sets for stock assessments and baseline MPA monitoring. Our sampling showed no significant difference in mean fish length or diversity between the two protocols for the five most common nearshore fish species captured, and three of the five species showed no significant difference in CPUE. Cabezon (Scorpaenichthys marmoratus), showed a significantly lower CPUE (50.5%) using the MLPA monitoring protocols compared to the commercial fishing protocol and black and yellow rockfish (Sebastes chrysomelas) had a significantly higher CPUE (310%) using the MLPA monitoring protocol. These findings provide a means of maintaining data continuity across the entire sample region and inclusion of earlier projects in the analyses of nearshore fish populations of the region. With the linkage of these two studies we provide important baseline data for the Cambria MPA from before it was established in 2007. Fish populations were compared on a year-to-year basis within each location, and between the different locations. I found several main factors helped to explain differences in size and abundance across time within individual locations, and across the three locations. These factors were inherent differences in habitat, establishment of MPAs, and changes in fishing pressure and post-larval recruitment. Cabezon were largest within Big Creek, followed by Piedras Blancas and Cambria which held the smallest fish, suggesting that fishing pressure is influencing fish size. However, cabezon were more abundant at Cambria than either other location suggesting that location is influencing abundance. Within Cambria, we are seeing an MPA effect with abundance within the MPA staying stable while the reference site is declining. Gopher rockfish (Sebastes carnatus) and black and yellow rockfish had similar trends with size and abundance between locations. Big Creek and Piedras Blancas held the largest fish, while Cambria was smaller. Both rockfish species were most abundant at Big Creek, followed by Cambria then Piedras Blancas. Size for these species is likely influenced by fishing pressure, and abundance is likely influenced by both fishing pressure and location. Both species increased in abundance 2004-2009 at Cambria, and this could be due to improved levels of post-larval recruitment. There is also a possible MPA effect for gopher rockfish at Cambria with a near significant divergence in size of fish between the MPA and reference site. Kelp greenling (Hexagrammos decagrammus) were similar in size and abundance between all sampling locations. There is a possible MPA effect at Cambria, with a significantly higher abundance than the reference site; however this difference predates the MPA’s establishment but could have been exacerbated by it. Lingcod (Ophiodon elongatus) size did not vary significantly between sites, but they were the most abundant at Cambria, followed by Piedras Blancas, then Big Creek, suggesting that habitat is influencing abundance. There was also a possible MPA effect on abundance of lingcod at Cambria with the MPA having a significantly higher abundance than the reference site. Similarly to the kelp greenling, these differences predated the MPA, but could have been exacerbated by its establishment, and abundance within the MPA has stayed stable, while the reference site was declining. Big Creek and Piedras Blancas have similar Shannon-Weiner diversity values, while Cambria has significantly lower. However, after MPA establishment at Cambria, the MPA has attained significantly higher diversity levels than the reference site. Over the short period of time that the Piedras Blancas and Cambria MPA have been established the populations within them have changed. However, there are no discernable trends in size, abundance and diversity between the MPA and reference sites at both locations. It is likely that with these slower growing, long-lived fish species that it will take more years for differences between the sites to manifest themselves.
23

Spatial and Temporal Comparisons of Gopher Rockfish (Sebastes carnatus) Life History and Condition in South Central California

Meyers-Cherry, Natasha Leigh 01 December 2014 (has links) (PDF)
Recent studies have shown environmental factors influence life history traits in fishes. Understanding intraspecific variability of life history characteristics and condition is necessary to determine local fisheries management strategies. Gopher rockfish, Sebastes carnatus, comprise 50% of the estimated shallow nearshore recreational rockfish catch in California, yet insufficient local data exist regarding life history traits and condition of this species. Our study locally defines growth parameters (maximum size and age), size (age) at reproductive maturity, and condition (hepatosomatic indices) for gopher rockfish in south central California. The growth parameter values of gopher rockfish from our study are similar to previously published research. However, our data also indicate that the current local gopher rockfish stock in south central California reaches reproductive maturity at a larger size and an older age when compared to gopher rockfish sampled throughout central California (primarily in Monterey) between 1977-1982. Furthermore, we examined spatial and temporal differences in life history information, within and outside of two south central California Marine Protected Areas (MPAs) established in 2007, between two time periods. Our data show that the size and longevity of fish has increased after the establishment of MPAs.
24

Effects of fishing on a coral reef fish assemblage in Northeastern Brazil

De Moraes Carvalho, Felipe 15 February 2022 (has links)
Reef fisheries are important activities that support the livelihoods of millions of people. Reef fisheries exploit different habitats and typically target a diversity of species caught with a matching diversity of fishing gears. However, previous studies of reef fisheries have generally lacked detailed information on the catch and effort by gear and habitat type. In this dissertation, the sustainability of a coral reef fishery at the Marine Protected Area Costa dos Corais, Northeastern Brazil is assessed. In 1,833 landing interviews with local fishers, 100 fished species were identified and the total catch in kilograms for each species, the size composition of captured individuals and the habitat type exploited were recorded. First, the dissertation explores how fishing gears selected for distinct functional traits. A low competitive interaction between different gears was noted. Gears used in reef habitats selected for sedentary and benthic species, while gears used in coastal lagoons targeted highly mobile and pelagic. Second, the dissertation assesses how different gear affected the catch rates of coral reef fishes. Gears used on coral reef habitats had a more negative effect on catch rates than those used in coastal lagoons. The three gear types that affected catch rates more severely were hook and line, gillnet and cast net. Based on the results it is argued that the effects of reef fisheries on catch rates were highly depended on the vulnerability of target species. Finally, the dissertation assesses the ability of the fishing-down concept to assess the sustainability of the local fishery; the fishing-down is used to describe the process of moving away from catching large fish to progressively targeting smaller fish. I found strong support for the fishing-down, as fisheries decreased the average size of the fish assemblage and affected more heavily the catch rates of fishes with higher index of vulnerability. Overall results show that fisheries management should focus on the conservation of vulnerable taxa that are responsible for key ecological processes in coral reefs such as herbivory and coral predation. The decision-making process on management measures must be based on clear discussions with all stakeholders involved. / Doctor of Philosophy / Coral reefs are one of the richest environments on the planet, but overfishing threatens their conservation. Reef fishers use many techniques, or fishing gears, such as hook and line and nets, to catch a high diversity of fish species. Reef fisheries are often unsustainable as fishers are allowed to employ high levels of effort. Thus, studies are needed to assess the sustainability of coral reef fisheries and determine which gears are more negative to reef fishes. In a series of three studies, I investigated how reef fisheries affected fish communities in Northeastern Brazil. I used a total of 1,833 interviews with fishers in which I recorded the total catch for each species, obtained size of fish individuals, and asked about the environment that was exploited, coral reefs or coastal lagoons. First, I evaluated how the different gears selected for groups of species with unique life-history characteristics, such as size, mobility and period of activity. I found that gears such as hook and line and harpoon selected for species with sedentary traits that live near the bottom of the ocean, whereas nets selected for very mobile species that inhabit surface waters. In general, fishers did not compete for the same resources with different gears. Second, I assessed how the different gears affected the relative abundance of coral reef fishes. The three gear types that affected more heavily the relative abundance of fishes were hook and line, gillnet and cast net. I argue that the negative effects occurred because these gears caught species with characteristics that made them vulnerable to exploitation, such as slow body growth. Third the dissertation assesses the ability of the fishing-down concept to assess the sustainability of the local fishery; the fishing-down is used to describe the process of moving away from catching large fish to progressively targeting smaller fish. I found strong support for the fishing-down as the studied fisheries impacted the size and the abundance of local fishes. My results suggest that fisheries management should focus on the conservation of vulnerable fish responsible for key ecological processes such as herbivory and coral predation. The decision-making process regarding fisheries management must also be based on clear discussions with all stakeholders involved.
25

Assessment of Diver Impact During the Spiny Lobster Sport Season, Florida Keys, USA

Hartman, Mark Lewis 01 January 2012 (has links)
The Spiny Lobster (Panulirus argus) fishery in Florida is closed during the spawning season (March-July) except for a two-day recreational `miniseason' for sport divers in July, several days prior to the opening of the commercial fishing season. In Monroe County, recreational fishers, who possess a valid Saltwater Fishing License with crawfish stamp, are allowed to harvest six lobsters per day, each with a minimum carapace length of 76.2 mm (3.0 inches). During these two days, approximately 50,000 people attempt to catch lobster, and the number of boats visiting the reef has been estimated to be up to 900 times higher than during the regular lobster season. I quantified incidences of benthic damage that occurred during the August 2011 miniseason, as well as substrate type and benthos affected. Study sites at Eastern, Western, and Middle Sambos, each characterized by spur and groove reefs, represented different levels of protection within the Florida Keys National Marine Sanctuary. The Eastern Sambos is a research only area, the Western Sambos permits recreational SCUBA diving but does not allow harvest of marine resources, and the Middle Sambos allows both recreational diving and lobster harvesting. The "Impact Site", the Middle Sambos, allows lobster harvesting, and "Control Sites", The Eastern and Western Sambos, were off limits to lobster harvesting. All sites were assessed three times before and three times after the miniseason at four locations within each of the three reef areas. Research divers conducted 30-minute, random-swim surveys cataloging incidences and magnitudes of benthic damage and counting legal-sized Spiny Lobster observed on reefs. Data were collected and analyzed using analysis of variance following the `Before-After, Control-Impact, Paired-Series' (BACIPS) design. I found an increase in the incidences of benthic damage at the Impact sites in the three surveys conducted after the miniseason, while no significant change occurred in Control sites. This suggests that detectable benthic damage associated with lobstering activity occurred during the miniseason, at least partly as a consequence of diver impacts while searching for and capturing Spiny Lobster. In addition to SCUBA gear, divers typically also bring gloves, a three-foot (92 cm) tickle stick, a hand net, a lobster gauge, and a lobster bag, all of which make buoyancy control more challenging. By actively searching for and attempting to capture Spiny Lobster, which are cryptic and maintain close proximity to the reef, lobster-seeking divers damage the benthos at higher rates than divers engaged in non-consumptive recreational activities.
26

All’s Whale that Ends Whale: How Correctly Identifying Antarctic-Feeding Grounds of Oceania Humpbacks Could Save an Endangered Population

Holmes, Davey 01 January 2016 (has links)
Although major whaling practices have ceased, increasing human involvement and influence in the world’s marine ecosystems continue to adversely effect global whale populations. It is a major concern throughout Antarctic waters, where endangered Oceania Humpback Whales (Megaptera novarangliae) annually feed. This study analyzes the extent to which a proposed marine protected area within the Ross Sea may indirectly harm the last remaining endangered population of Humpbacks. Using current satellite tracks of southern Humpback migrations, this model maps the effects of displaced Toothfish fisheries, and suggests further conservations efforts, based on New Zealand’s Precautionary Approach, to protect these vulnerable whales.
27

Approche économique et institutionnelle de l'influence des Aires Marines Protégées sur le développement durable des territoires en Méditerranée / Economic and institutional approach of Marine Protected Areas effects on local sustainable development in the Mediterranean

Mangos, Anaï 18 December 2015 (has links)
En Méditerranée, un Hotspot de biodiversité, des Aires Marines Protégées (AMP) ont été instaurées dès les années 1960 pour protéger la biodiversité marine pour des raisons éthiques, culturelles et fonctionnelles, du fait de la contribution au bien-être des individus. Aujourd’hui, la mise en œuvre des AMP s’inscrit dans un environnement institutionnel formalisé à différents échelons : national, méditerranée, européen, et global avec la Convention pour la Diversité Biologique (CDB). Dans ce contexte de gouvernance environnemental prometteur, le constat de la couverture de protection par les AMP demeure pourtant en-dessous des engagements pris par les pays riverains dans les différentes instances évoquées. Peu de moyens sont mis en œuvre et les AMP sont nombreuses à être peu effectives. Face à ce constat décevant les gestionnaires des AMP de Méditerranée ainsi que leurs partenaires se mobilisent pour le renforcement de la lutte contre la dégradation des biens communs que représente la biodiversité marine et côtière. L’objectif de cette thèse est de contribuer à cet effort en éclairant les éléments favorables à l’effectivité et l’efficacité des AMP. Les AMP, dont la finalité est la protection de la biodiversité, établissent des règles d’usages liés à la biodiversité marine et côtière et mettent en œuvre des activités spécifiques au sein d’un espace clairement défini. Ceci entraîne à la fois des contraintes et des opportunités pour la trajectoire de développement durable notamment celle du territoire écologiquement et socio-économiquement liée à l’AMP. Cette thèse vise à montrer que les AMP sont des dispositifs institutionnels qui s’inscrivent dans des systèmes socio-écologiques. Dans ce contexte, outre les mécanismes de résilience des écosystèmes, la capacité des AMP à générer des bénéfices pour le développement durable des territoires repose notamment, d’une part sur la capacité des parties prenantes à s’adapter au changement de règles, à faire face aux contraintes et à saisir les opportunités ; et, d’autre part, sur la capacité des AMP à s’appuyer sur des réseaux sociaux denses pour favoriser la conformité des comportements et donc l’effectivité de l’AMP. La première partie, centrée sur l’approche institutionnelle, permet de considérer les AMP au sein de leur système socio-écologique. Elle s’ouvre avec le premier chapitre qui définit le rôle attribué aux AMP à travers la construction de cet outil depuis le début du XXème siècle en s’appuyant sur la construction aux différents échelons imbriqués de notions cadre, telle que la biodiversité, le développement durable et la gouvernance du milieu marin. Le deuxième chapitre fait le bilan de la situation actuelle des AMP en Méditerranée face à leurs objectifs d’effectivité et d’efficacité. Une typologie réalisée à partir des AMP méditerranéennes est proposée afin de contribuer à la définition de stratégies différenciées pour renforcer des AMP existantes et à venir dans le bassin. Le troisième chapitre, qui clôt la Partie 1, analyse les AMP en tant que dispositifs institutionnels. Il éclaire la nature des effets et des enjeux liés à la création d’AMP, et discute la concrétisation de facteurs clés pour faciliter la réussite des AMP. La deuxième partie, centrée sur l’intégration des AMP dans le développement durable des territoires, s’ouvre avec le quatrième chapitre qui analyse la formation des bénéfices et des coûts générés par les AMP de Méditerranée sur le capital naturel, le capital humain et le capital social (et indirectement sur le capital physique) disponibles sur le territoire. Le dernier chapitre montre comment l’évaluation socio-économique des effets des AMP peut renforcer les AMP en dépassant les limites de l’évaluation économique concentrée sur certains bénéfices liés aux services écosystémiques ; par la réalisation de méthodes d’évaluation et des processus complémentaires qui encouragent l’engagement des parties prenantes auprès des AMP. / In the Mediterranean, a biodiversity Hotspot, Marine Protected Areas (MPAs) were introduced in the 1960s to protect biodiversity for ethical, cultural and functional reasons, as biodiversity contributes to the well-being. Today the AMP implementation is part of a formalized institutional environment at various levels: national, Mediterranean, European, and global with the Convention on Biological Diversity. In this promising context of environmental governance, protection cover by AMP yet remains below the commitments of riparian countries in the various governance bodies mentioned. Few resources are expanded and many MPAs are likely to be low effective. Given this disappointing finding the managers of Mediterranean MPA and their partners are gathering to strengthen efforts against the degradation of our common good that is marine and coastal biodiversity. The objective of this thesis is to contribute to this effort by enlightening elements favorable to the effectiveness and efficiency of MPAs.MPAs are intended to protect biodiversity and therefore establish rules related to the use of marine and coastal biodiversity and implement specific activities within their clearly defined space. This causes both constraints and opportunities for the sustainable development path especially that of territory environmentally and socio-economically connected to the MPA. This thesis aims to show that MPAs are institutional arrangements that are part of a social-ecological system. In this context, besides the mechanisms of ecosystem resilience, MPAs ability to generate benefits for the sustainable development of territories is based on the one hand on the ability of stakeholders to adapt to the change of rules, address the constraints and seize opportunities, and, on the other hand, on the ability of MPAs to rely on dense social networks to encourage behavior compliance and thus MPA’s effectiveness.The first part adopts an institutional approach that enables to consider MPAs in their socio-ecological system. It opens with the first chapter that defines the role attributed to AMP through the elaboration of this tool since the early twentieth century building on the construction at different levels nested of framework notions such as biodiversity, development sustainability and governance of the marine environment. The second chapter, looks over the current situation of MPAs in the Mediterranean in regard to their objectives of effectiveness and efficiency. A typology of Mediterranean MPAs is proposed to help the definition of differentiated strategies so as to strengthen existing and future MPAs in the basin. The third chapter, which ends the first part, analyzes the MPAs as institutional arrangements that enlighten on the one hand the nature of the effects and stakes related to the establishment of MPAs, and on the other hand, discusses the empirical forms of key success factors to facilitate MPAs.The second part, focusing on the integration of MPAs into the sustainable development of territories, opens with the fourth chapter which analyzes the formation of the benefits and costs generated by the Mediterranean MPAs on natural capital, human capital and social capital (and indirectly on physical capital) available in the territory. The last chapter shows that socio-economic assessment of the effects of MPAs can help strengthen MPAs, by going beyond the limits of economic valuation of particular benefits related to ecosystem services; and implementing complementary assessment methods and processes helping stakeholder engagement towards AMP.
28

"Des réserves sous réserve" : acceptation sociale des Aires Marines Protégées : l'exemple de la région sud-ouest de l'océan Indien / "Reserves with reservations" : social acceptance of marine protected areas : the exemple of the western Indian Ocean region

Thomassin, Aurélie 28 March 2011 (has links)
Les Aires Marines Protégées (AMPs) sont communément reconnues comme des outils de gestion durable du milieu marin, principalement destinés à la conservation de la biodiversité. L’évaluation de leur efficacité et de leur performance constitue, aujourd’hui, un champ de recherche en pleine expansion qui répond à une demande locale des gestionnaires, comme à une nécessité plus globale de rapportage (reporting) auprès des décideurs et bailleurs de fonds. Jusqu’ici, la plupart des recherches utilisent un angle d’analyse strictement biologique, laissant de côté l’étude des impacts socio-économiques. La réussite des AMPs repose pourtant sur trois piliers d’importance égale : la durabilité écologique, la faisabilité économique et l’acceptation sociale. Cette thèse s’intéresse aux impacts sociaux des AMPs et à la nécessité d’imaginer des outils pertinents permettant aux gestionnaires d’évaluer et de suivre l’acceptation sociale. Plus précisément, elle a pour objectif d’élaborer une méthode standardisée de suivi des dynamiques sociales au sein des AMPs, qui permette la construction d’indicateurs utiles pour la gestion locale comme pour le rapportage. A partir du cas de la Réserve Naturelle Marine de La Réunion, une démarche géographique, basée sur le concept de Territoire, est mise en place pour caractériser et mesurer l’acceptation sociale. Elle passe par la réalisation d’un diagnostic socio-économique, permettant l’identification des enjeux territoriaux des usagers. Ces enjeux sont l’expression des valeurs que les individus accordent aux services que rendait le territoire avant qu’il ne soit protégé et également de la crainte de perdre ces services. L’acceptation sociale de l’AMP est ainsi fonction du degré de satisfaction des enjeux territoriaux des acteurs. Des indicateurs de suivi de cette satisfaction, principalement basés sur le recueil de perceptions, sont proposés pour estimer l’acceptation sociale. Dans un second temps, la question de la généricité de cette démarche est posée. Sa déclinaison au cas du Parc Marin de Mohéli (Comores) et, plus rapidement, à l’AMP de Velondriake (Madagascar), montre que la territorialité des acteurs est un facteur majeur dans la construction de l’acceptation sociale, quel que soit le contexte politique et socio-économique local. Il existe, en revanche, des facteurs contextuels qui entrent également en ligne de compte et qui rendent incomplète la généricité de l’approche territoriale. / Marine Protected Areas (MPAs) have been widely adopted as sustainable management tools for marine ecosystems, mainly dedicated to the conservation of biodiversity. There is growing interest in research projects designed to assess their effectiveness and performance, in response to local demands from managers, as well as to a more global need for reporting mechanisms for decision-makers and funders. Until now, scientists have tended to evaluate effectiveness from a strictly biological perspective, without studying the socio-economic impacts. However, the success of MPAs is driven by three criteria of equal importance: ecological sustainability, economic feasibility and social acceptance. This thesis addresses the social impacts of MPAs and focuses on the need to imagine relevant tools to help managers estimate and monitor social acceptance. It aims to develop a generic methodology to monitor social dynamics in MPAs, in order to build appropriate indicators for local management and for reporting purposes. From the case of the Natural Marine Reserve of Reunion Island (French overseas department in the Western Indian Ocean), a geographical approach based on the Territory concept is developed to qualify and monitor social acceptance. A socio-economic diagnostic is made, to identify the users' territorial stakes, i.e. the values that individuals assign to the services rendered by the territory before it was protected and also to the fear of losing them. Thus, the social acceptance of MPAs depends on the user' levels of satisfaction with respect to their territorial stakes. Indicators based on perceptions are proposed, to monitor thesesatisfaction levels and hence to estimate social acceptance. The second part addresses the issue of the genericity of this approach. It is applied to the cases of Mohéli Marine Park (Comoros) and, more briefly, Velondirake MPA (Madagascar). Results show that users’ territoriality is a key factor in understanding social acceptance, whatever the local political and socio-economic context. Nonetheless, as certain contextual factors must also be taken into account, the territorial approach is not entirely generic.
29

The implications of co-locating marine protected areas around offshore wind farms

Ashley, Matthew January 2014 (has links)
Offshore wind farm (OWF) construction in the UK is progressing rapidly alongside increasing spatial pressures on marine ecosystems and social and economic activities. A need for increased protection of habitats, species and ecological processes that support environmental and economic benefits is being met by designation of marine protected areas (MPAs). Mitigation and spatial planning solutions are required to enable protection of vital ecological habitats, features and processes and support sustainable economic development. A potential solution is to co-locate OWFs and MPAs. This study uses a multi-disciplinary approach to examine if evidence on the environmental effects of existing OWFs and associated effects on fishing activity (as an existing resource use) benefits MPA goals. Through a systematic review and meta-analyses of existing data, knowledge of OWF effects on species abundance and economic effects on fishing were identified as key evidence gaps. The ecological evidence need was approached through a case study of ecological effects of North Hoyle OWF, North Wales, UK, using existing pre and post-construction monitoring data, as well as primary baited remote underwater video data, collected 5 years later (8 years post-construction). Results suggested habitat and species recovered to a stable state that showed some community differences to pre-construction conditions. The presence of OWF monopiles is likely to have increased existing heterogeneity of substratum and increased opportunities for scavenging species. Species benefitting and disadvantaged by habitat provided within the OWF reflected meta-analyses trends. Extended baseline monitoring to provide confident identification of natural levels of variation in sediment and fauna was lacking. Analysis of fishing activity and landings before and after OWF construction in three UK case study regions approached effects on resource users. Fishing activity in the three case study areas showed broad scale similarity to national trends. Small-scale activity patterns indicated greater reductions in mobile (towed) fishing gear effort near to operating OWFs than in static gear activity (using pots or static nets). Semi-structured interviews conducted with fishermen in each region revealed loss of ground and disruption as negative effects from OWFs, in addition to existing pressures. Benefits including habitat creation and species augmentation, as well as reduction of cumulative lost ground, were identified by fishermen from co-location of MPAs and OWFs. Ecological effects of OWFs suggested benefits from habitat creation, species augmentation and potential for protection of sandbank habitats between monopiles. Mitigation requirements were identified to maximise these potential benefits to an MPA network.
30

Suivi et évaluation de la pêche professionnelle au sein d'une Aire Marine Protégée : protocoles d'enquêtes et indicateurs de pression et d'impact. Application au Parc Marin de la Côte Bleue.

Leleu, Kevin 30 March 2012 (has links)
La surexploitation des ressources halieutiques a conduit à une crise majeure du secteur de la pêche professionnelle. Dans ce contexte, les pêcheries artisanales, et notamment les pêcheries aux petits métiers côtiers, apparaissent comme des modes d'exploitation potentiellement durables des ressources côtières. La diversité des engins utilisés et des espèces ciblées rend néanmoins complexe le suivi de cette composante importante de la pêche professionnelle. L'activité de pêche artisanale reste ainsi très peu évaluée en Méditerranée, et notamment à l'échelle d'une Aire Marine Protégée (AMP). Les AMP sont pourtant de plus en plus utilisées comme des outils de gestion de ces pêcheries, les effets des différentes mesures de gestion mises en place étant à même de bénéficier aux pêcheurs professionnels. A l'heure où le nombre d'AMP se multiplie, il apparaît alors nécessaire pour les gestionnaires comme pour les scientifiques de disposer d'indicateurs permettant de suivre l'activité de pêche professionnelle sur le territoire d'une AMP, et d'évaluer les effets de la gestion sur cette activité. Un protocole d'enquête pour le suivi de la pêche artisanale aux petits métiers côtiers a ainsi été mis en place entre juillet 2009 et juin 2010 au sein du Parc Marin de la Côte Bleue (PMCB), AMP méditerranéenne française comprenant deux réserves marines d'âge et de taille différents. Les données récoltées ont permis d'identifier sept métiers principaux pratiqués par les pêcheurs du PMCB, et de les caractériser par un groupe d'espèces cibles, un engin, un territoire et une période de pêche. L'effort de pêche et les captures ont alors pu être estimés à partir de ces métiers. / The overexploitation of fishery resources has led to a major fisheries crisis. In this context, artisanal fisheries, and in particular small-scale coastal fisheries, appear as relevant alternatives for a sustainable use of coastal resources. But the diversity of fishing gears and targeted species diversity make it difficult to assess this important component of the commercial fishery. Hence, the activity of small-scale artisanal fishing remains poorly known in the Mediterranean Sea and few studies focus on an assessment of this activity at the scale of a Marine Protected Area (MPA). MPAs are yet more and more used as management tools for these fisheries, as protection effects and targeted access regulations may benefit to commercial fishers. As many MPAs are going to be established in the short term, it seems necessary for managers and for scientists, to have indicators to monitor the artisanal small-scale coastal fishing activity within an MPA, and to estimate the effects of MPA management on this activity. A field protocol was defined and implemented between July 2009 and June 2010 within the Parc Marin de la Côte Bleue (PMCB), a French Mediterranean MPA including two marine reserves of different age and size. The collected data allowed identifying seven main métiers within the PMCB, and characterizing them by group of target species, type of gear, fishing grounds and fishing periods. Fishing effort and catch were estimated. In the Côte Bleue area, 3 512 fishing trips and 4645 fishing operations were performed by 30 active boats during the studied period, for a total of 10 300 km of immersed nets.

Page generated in 0.1021 seconds