6 resultados para fishing areas

em Deakin Research Online - Australia


Relevância:

30.00% 30.00%

Publicador:

Resumo:

An evaluation of the effectiveness of Marine Protected Areas (MPAs) in temperate waters of Australasia has been conducted for this thesis. The aim was to identify key elements needed in a strategy for establishment and management of MPA’s in temperate waters of Australasia. This aim was achieved by assessing how effective a sample of MPA’s has been in meeting the conservation objectives for their establishment and by identifying factors that have contributed to success or failure of the MPA’s in meeting these objectives. Particular attention was paid to the objectives of ecological sustainability and biodiversity preservation. A MPA for the purposes of this research was defined as an area of coastal or marine environment, with a substantial subtidal component, set aside by law primarily for conservation purposes. The study region encompassed the coastal zones of Victoria, Tasmania and South Australia (Australia) and New Zealand. The questions posed in order to address the aim of this thesis were; a) Have existing MPA’s been effective in achieving conservation objectives? b) What have been the important influences on effectiveness of existing MPA’s? c) What are the key elements required for implementation of effective MPA’s? The thesis is divided into three parts. Part I is a review of the literature on implementation and effectiveness of MPA’s. Part II presents a detailed evaluation of one MPA: Point Lonsdale Marine Reserve (PLMR), Victoria, Australia. Part in is an evaluation of a number of Australasian temperate MPA’s based on information provided in a survey of people involved in management of MPA’s, and from a variety of published and unpublished documents. The MPA’s are described, evidence about ecological effectiveness is presented and factors that have enhanced and limited the ability of these MPA’s to achieve conservation objectives are derived. A substantial amount of scientific evidence was found for increases in abundance, mean size and size range of fish and invertebrate populations within the boundaries of ‘no-take’ MPA’s, Some evidence was found for ‘spillover’ of adults and juveniles into adjacent fishing grounds. Ecological effects detected within ‘no-take’ MPA’s in Australasia matched those described in the literature. The abundance and mean size of a number of previously exploited species have increased, migration into adjacent fishing grounds has been documented, and species richness has increased in at least one MPA. The PLMR was established primarily to protect the scientifically significant intertidal rock platforms. The results of the case study suggest that this objective has been achieved. Opinions about effectiveness were obtained for 28 MPA’s. Of these 19 were considered to be achieving some objectives and 10 were considered to be performing well in terms of overall ecological effectiveness. Positive effects on biodiversity were generally assumed as a result of reduction of damaging anthropogenic effects on habitat. Many questionnaire respondents noted an increase in community awareness about and support for marine conservation as a result of proclamation of MPA’s, Overall, the results support the value of MPA’s for sustainability of fish stocks and preservation of biodiversity, but there is substantial doubt over whether some of the MPA’s are too small to maintain benefits in the long-term. ‘No-take’ MPA’s, particularly those more remote from the impacts of human activities, have been the most effective in achieving objectives. A number of interacting factors important to eventual success of MPA’s were identified. The most important enhancing factors identified for the PLMR were physical attributes that limit the extent of human use and a strong conservation ethic amongst many of the visitors to this marine reserve. Limiting factors were far more numerous. Of most concern is the inadequacy of at-site management. Almost half of visitors to the area were not aware of its marine reserve status, despite the fact many were frequent visitors. The need for better educational and interpretative material on-site is highlighted by the results of the PLMR visitor survey. A total of 56 factors that have enhanced effectiveness and 46 factors that have limited effectiveness of Australasian temperate MPA’s were identified. A number of factors were important in more than one MPA and this was used to derive a set of critical, or key, factors. For example, a conclusion of all three approaches used in this study is that failure to implement day-to-day management through lack of resources was a major constraint on effectiveness. The importance of MPA’s to marine conservation depends, in part, on how well they are managed. The key factors that influence MPA effectiveness were used as the basis for derivation of the main requirements for implementation of MPA’s that will be capable of meeting the objectives for their establishment. The most important needs are: • that ‘no-take’ areas surrounded by buffer zones form the basis for a system of MPA’s; • that a high level of protection is bestowed by legislation and regulations; • that a minimum size be set for the ‘no-take’ core areas; • that the selection of sites for MPA’s takes into account land-based impacts; • that institutional arrangements are developed specifically for MPA’s; • that funding for MPA’s is increased to enable effective management; • that day-to-day management is implemented in all MPA’s, with enforcement and education programs as priority areas; • that a monitoring program for one or more MPA in each 'State' is established to provide evidence of ecological effects of reservation; • that public and stakeholder involvement in development and implementation of MPA’s is encouraged as this will influence the degree of public support and compliance; • that community-based programs to educate the general public, stakeholders, the media and decision-makers about the value of MPA’s are essential; and • that measures to reduce financial impact on affected stakeholders be implemented.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

As part of international obligations and national policies, most nations are working toward establishing comprehensive, adequate, and representative systems of terrestrial and marine protected areas (MPAs). Assigning internationally recognized International Union for Conservation of Nature (IUCN) protected area categories to these MPAs is an important part of this process. The most recent guidance from the IUCN clearly states that commercial or recreational fishing is inappropriate in MPAs designated as category II (National Park). However, in at least two developed countries with long histories of protected area development (e.g., Canada and Australia), category II is being assigned to a number of MPAs that allow some form of commercial or recreational fishing. Using Australia as a case study, this article explores the legal and policy implications of applying protected area categories to MPAs and the consequences for misapplying them. As the Australian Government is about to embark on potentially one of the largest expansions of MPA networks in the world, ensuring the application of IUCN categories is both transparent and consistent with international practice will be important, both for the sake of international conventions and to accurately track conservation progress.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The southern rock lobster Jasus edwardsii is a commercial species that has benefited from the complete protection offered by no-take reserves, with higher abundances and larger animals recorded in reserves than in adjacent fished areas. What remains unclear is whether there is any change in the diet of lobsters in reserves, for example, as a result of increased intraspecific competition for food. We used combined chemical tracers to examine the diet of lobsters in fished and reserve areas in 2 bioregions in eastern Tasmania. δ15N values of lobsters were richer in fished than in reserve areas, indicating that lobsters eat a greater proportion of food items from higher trophic levels in fished areas. Mixing models suggest that ascidians, sea urchins and the turbinid gastropod were all important food sources for lobsters, but the importance of these food items differed between bioregions. This spatial variability may suggest that the small size of the reserve in one bioregion is inadequate at ensuring the diet of lobsters is protected from fishing pressure. Fatty acid profiles of lobsters supported the importance of these food sources to lobsters. Differences between bioregions, or inside and outside of reserves, were not apparent using fatty acids. The present study highlights that lobster fishing has the capacity to alter the trophic status of prey for generalist predators and suggests that fatty acid analyses may be limited in detecting changes in the dietary composition of such generalist feeders.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Historically, collecting nearshore habitat information has been problematic. Existing methods, such as aerial and satellite image interpretation are limited due to the attenuation of light in the water column obscuring the seabed structure. The advent of airborne bathymetric LiDAR (Light Detection and Ranging) systems (laser scanning of the seabed) now provides high-resolution seabed ‘images’ in areas that were previously difficult to survey. LiDAR imagery is available for the entire coastline of Victoria, Australia to depths of around 25 m, after being initially collected for climate change modelling by the Future Coasts Program (http://www.climatechange.vic.gov.au/adapting-to-climate-change/future-coasts). This dataset has provided the opportunity to test its applicability to inform fisheries management. Detailed geophysical information combined with spatially explicit AbTrack GPS located fisheries records and targeted genetic sampling is used in this study to provide a better understanding of the extent of available fishing grounds, direction of fishing effort and stock population structure within the Victorian western zone abalone fishery.
The species distribution modelling technique MaxEnt was used to produce a potential habitat suitability map for abalone in an attempt to capture the effective footprint of the  fishery. Also, by interrogating the spatially defined effort localities, we demonstrate an approach that may be used to identify areas where fishing effort is concentrated, and how this parameter changes temporally.
Despite barriers to adult dispersal (soft sediment barriers between reef patches), the genetic study indicates that larval movement is able to homogenize the gene pool over  large geographic distances. The western, central and eastern zone abalone stocks in Victoria were found to be a single large panmictic unit. This indicates high levels of stock connectivity and no obvious impacts of Abalone Viral Ganglioneuritis (AVG) on the genetic health of western zone stocks. We used detailed seafloor structure information interpreted from LiDAR to inform a replicated hierarchical fine scale genetic sampling design. We demonstrated that there may be extensive migration among abalone stocks across the Victorian abalone fishery.
This is contrary to previous studies that suggest recruitment is highly localised. In combination, these findings provide a valuable insight into the biology of H. rubra and immediate benefits for fisheries management. We discuss these results in the context of predicting resilience and adaptive potential of H. rubra stocks to environmental pressures and the spread of heritable diseases.
Adoption pathways are also provided to benefit future stock augmentation activities to catalyse the recovery of AVG affected reef codes. As larval dispersal is likely to be spatially and temporally variable, some AVG affected stocks are likely to recover through natural recruitment, while others will benefit from augmentation activities to ‘kick-start’ stock recovery. Evidence of neutral genetic homogeneity across Victorian reef codes suggests that the relocation of animals is unlikely to have significant genetic risks; however the potential for locally adaptive genetic differences may exist, and should be taken into consideration in future stock augmentation planning.
When combined, the spatial and genetic analyses provide valuable insights into stock productivity within the western zone fishery. Reefs appear to be expansive and support much available habitat, and the movement of larvae among reef structures is likely to be extensive in this region. Consequently, we propose that colonisation success and productivity is likely to be driven by ecological factors such as resources and/or competition, or physical factors such as wave exposure.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Although the flesh-footed shearwater Puffinus carneipes is a species with large population sizes (tens of thousands of breeding pairs) and widespread sub-tropical distribution across Australasian water masses, it is among the species most threatened by longline fisheries mortality in this region. While bycatch mitigation measures have been very successful in reducing mortality in some species, bycatch of flesh-footed shearwaters is still high, with captures estimated to exceed the sustainable take of 514 birds yr-1 by nearly 200 birds for New Zealand fisheries alone. Management agencies aiming to reduce the impact of fisheries mortality on the populations need to understand which marine areas are being used by flesh-footed shearwaters to better target fishery monitoring and mitigation efforts. Foraging studies of seabirds tell us about their use of resources, i.e. the way species segregate the available habitat and help to identify threats that may affect population viability. Breeding shearwaters were tracked from 2 New Zealand colonies using GPS loggers. Individuals foraged over shelf and deep oceanic waters up to 1200 km from their nesting sites during incubation but were mainly within 370 km during early chick rearing. The intensity of potential interactions increased for trawl and surface longline fishing between the January and February study periods but remained at a similar level for bottom longline fishing. Following the field data collection, changes to fishery monitoring were implemented in the areas where shearwaters foraged.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The world’s oceans cover about 70% of our planet. To safeguard the delicate ecological and environmental functions of the oceans and their remarkable biodiversity, networks of marine protected areas are being created. In some of these areas, human activity is restricted to non-exploitative activities and in others it is managed in a sustainable way. Australia is at the forefront of marine conservation, with one of the largest systems of marine protected areas in the world.Big, Bold and Blue: Lessons from Australia’s Marine Protected Areas captures Australia’s experience, sharing important lessons from the Great Barrier Reef and many other extraordinary marine protected areas. It presents real-world examples, leading academic research, perspectives on government policy, and information from indigenous sea country management, non-governmental organisations, and commercial and recreational fishing sectors. The lessons learnt during the rapid expansion of Australia’s marine protected areas, both positive and negative, will aid and advise other nations in their own marine conservation efforts.The book is ideal reading for marine planners and managers across the globe; academic institutions where research on marine environments occur; government agencies across the world implementing and creating policy around MPA development; non-government organisations involved in lobbying for MPA expansion; and fisheries agencies and industry stakeholders.