Integration of numerical models in geographic databases: the case of Sado estuary management

Geographic information systems (GIS) are now widely applied in coastal resource management. Their ability to organise and interface information from a large range of public and private data sources, and their ability to combine this information, using management criteria, to develop a comprehensive picture of the system explains the success of GIS in this area. The use of numerical models as a tool to improve coastal management is also widespread. Less usual is a GIS-based management to ol implementing a comprehensive management model and integrating a numerical modelling system into itself. In this paper such a methodology is proposed. A GIS-based management tool based on the DPSIR model is presented. An overview of the MOHID numerical modelling system is given and the method of integrating this model in the management tool is described. This system is applied to the Sado Estuary (Portugal). Some preliminary results of the integration are presented, demonstrating the capabilities of the management system.

Stakeholder participation in estuary management: the development of Victoria's Estuary Entrance Management Support System

Stakeholder involvement in the management of estuaries is a necessary element of good environmental governance. In Victoria, Australia, a key challenge for estuary managers is whether or not estuaries should be artificially opened since many river mouths close ‘naturally’ from time to time. Estuary closure resulting in raised estuarine water levels leads to economic and social impacts on local communities. In the past these effects have been addressed by artificial river mouth openings, often without reference to associated environmental impacts. This article discusses the development and features of an Estuary Entrance Management Support System and considers its performance against principles of effective environmental management. It concludes that, in bringing together technical information with stakeholder input through a structured process, such a system makes a useful contribution to improving estuary entrance management.

‘Bright spots’ for estuary management in temperate Southern Australia

Estuaries are a transition zone for fresh and saline water and sediments, providing a range of ecosystem services for the local population, infrastructure and industries located in their environs. They are also governance transition zones where jurisdictions often overlap and focused attention is often lacking. As Australia’s population continues to expand, particularly in the south, estuaries are increasingly becoming popular locations for settlement due to their picturesque surrounds and accessibility for water-based activities. This results in expanding human and industry activities and pressures along estuaries and adjacent coastal settings impacting ecosystem service delivery. The absence of dedicated national and state estuary legislation in addition to decades of poor land and waterway management decisions paints a ‘doom and gloom’ picture for temperate southern Australian estuaries. Against this backdrop, there are number of estuary ‘bright spots’ where natural resource management bodies in strong partnership with local actors are moving forward in overcoming challenges to estuary conservation. Using case studies, this paper describes the key elements for effective estuary management that can lead to improved estuary health.

The value of oral history in natural resource management : the Balcombe Estuary Reserve, Mount Martha, Victoria

This study investigates the benefits of using oral history as a tool for the sustainable management of estuaries. Twenty-two semi-structured interviews were conducted to generate oral history records for the Balcombe Estuary Reserve, a small estuary in a periurban zone on the Mornington Peninsula, Victoria. These interviews establish a more complete picture of changes in land use and ecological change to the estuary since European settlement of the area, and document community values. The interviews were followed with a survey to further explore management issues in the area. Use of oral history was found to be an effective approach to assist holistic estuarine management, especially when complemented by other sources of information.

Integrating knowledge systems in local coastal management; the case of an estuary entrance management support system (EEMSS) in Australia

The management of social, economic, and ecological assets in coastal zones is fundamental to the maintenance and sustainability of coastal resources. A significant issue in this discussion is the role of governance structures. In Australia the governance of the coastal zone includes a range of institutional authorities, processes, and procedures that set the context for decision making about coastal management. As well as the formal institutional arrangements there is also a maze of other interests such as development commissions, NGOs, Indigenous Native Title holders and other stakeholders including recreational interests. A major issue for governance arrangements is the considerable gap that often exists between how those interests interpret and develop their positions especially when the knowledge is derived from different systems – scientific, managerial, lay and indigenous. This paper will explore the development of an Estuary Entrance Management Support System (EEMSS) in south west Victoria Australia. The EEMSS is a decision support tool to assist estuary managers in determining whether to artificially open a river mouth. A significant part of the process adopted was community participation which involved a ‘steps’ approach to engage local community groups and landholders. It is the process of engaging different knowledge systems in a meaningful conversation that has led to a system that now gains support from all of the stakeholders in the management of different estuaries. The paper will discuss the processes that surround the EEMSS and outline some lessons that arise in context of the ‘project state’.

Towards more integrated and participatory coastal management : insights from Victoria’s Estuary Entrance Management Support System.

Participation and integration are core elements of coastal management. A key argument is that involving stakeholders from the broader community in collaborative coastal management allows for a more reflexive approach to consideration of ecological science outputs. However the role of stakeholder participation is still problematic especially when the involvement is short term and limited in its knowledge co-production. We argue for the development of a participatory logic that includes five key elements: the institutionalization of the processes that derive from stakeholder co-production and co-management; the ability and capacity to make meaningful decisions about issues of importance in an on-going way; the inclusion of all stakeholders in the process; the flexibility of central policies that enable participation by stakeholders at local level; the allowance for pathways for the uptake of all knowledge systems. Using this approach we report in this paper on the Estuary Entrance Management Support System (EEMSS) and ask whether this is a model system for answering the following questions as part of participatory logic: What types of collaborative activities can be used to improve the management of coastal zones? Are these activities a sufficient pathway for integrating different knowledge forms including science into coastal management? How important is stakeholder participation to science uptake? How can stakeholder participation be institutionalized in coastal management?

A resource management scenario for traditional and scientific management of pink shrimp (Farfantepenaeus paulensis) in the Patos Lagoon estuary (RS), Brazil

Abstract Background This article aims to discuss the incorporation of traditional time in the construction of a management scenario for pink shrimp in the Patos Lagoon estuary (RS), Brazil. To meet this objective, two procedures have been adopted; one at a conceptual level and another at a methodological level. At the conceptual level, the concept of traditional time as a form of traditional ecological knowledge (TEK) was adopted. Method At the methodological level, we conduct a wide literature review of the scientific knowledge (SK) that guides recommendations for pink shrimp management by restricting the fishing season in the Patos Lagoon estuary; in addition, we review the ethno-scientific literature which describes traditional calendars as a management base for artisanal fishers in the Patos Lagoon estuary. Results Results demonstrate that TEK and SK describe similar estuarine biological processes, but are incommensurable at a resource management level. On the other hand, the construction of a “management scenario” for pink shrimp is possible through the development of “criteria for hierarchies of validity” which arise from a productive dialog between SK and TEK. Conclusions The commensurable and the incommensurable levels reveal different basis of time-space perceptions between traditional ecological knowledge and scientific knowledge. Despite incommensurability at the management level, it is possible to establish guidelines for the construction of “management scenarios” and to support a co-management process.

An examination of the techniques used to capture mangrove crabs, Ucides cordatus, in the Mamanguape River estuary, Northeastern Brazil, with implications for management.

The present research, undertaken in a mangrove swamp in northeastern Brazil (Mamanguape River Estuary), examined the factors that led to the overwhelming acceptance of the tangle-netting technique by crab harvesters in detriment to the now illegal tamping technique. Both techniques are the only ones currently used at our study site and in many other areas in Brazil, despite being prohibited by law. Data were collected through direct observations to determine capture efficiency, productivity, daily production, selectivity, and harvesting effort, and through interviews with crab harvesters, focusing on their perceptions of the capture techniques, the conditions of crab stocks and the sales price of a dozen crabs. Our results indicated that the two capture techniques did not significantly differ in terms of their efficiency or productivity, but daily production rates differed significantly, being greater using tangle-netting. The tangle-netting permits a greater harvesting effort (6 hours and 34 min) compared to tamping (4 hours and 19 min). Tangle-netting is also less selective than tamping indicated by the larger number of captured smaller specimens, including females. This results in a lower average sales price for a dozen crabs caught by tangle-netting (US$ 0.95) compared to tamping (US$ 1.02). The greater daily production of crab harvesters using the tangle-netting technique nevertheless increased their net gain, explaining their preference for this method, Given that tangle-netting results in greater harvesting pressure but lower selectivity compared to tamping, it may potentially be less sustainable. All of the crab harvesters interviewed having more than 20 years of experience (n = 34) stated they perceived that stocks of U. cordatus had become reduced over the last 20 years, together with average crab sizes. It is now important to examine the structure of the local U. cordatus population and to assess its fishery to allow evaluating whether the illegal, but prominent tangle-netting and tamping mangrove crab capture techniques are sustainable or not. We further suggest improving the dialogue between decision makers and fishermen, which barely exists to date, to initiate a discussion about possible ways of resolving the current situation of illegality of the fishermen. This will be key to achieving effective sustainable co-management of this important natural mangrove forest resource.

How can science contribute for the sustainable management of natural resource? : Praia da Vitória Bay and Guadiana Estuary, a comparative study

Tese de Doutoramento, Ciências do Ambiente (Ordenamento do Território), 5 de Abril de 2013, Universidade dos Açores.

Eddy diffusivity: A single dispersion analysis of high resolution drifters in a tidal shallow estuary

In an estuary, mixing and dispersion resulting from turbulence and small scale fluctuation has strong spatio-temporal variability which cannot be resolved in conventional hydrodynamic models while some models employs parameterizations large water bodies. This paper presents small scale diffusivity estimates from high resolution drifters sampled at 10 Hz for periods of about 4 hours to resolve turbulence and shear diffusivity within a tidal shallow estuary (depth < 3 m). Taylor's diffusion theorem forms the basis of a first order estimate for the diffusivity scale. Diffusivity varied between 0.001 – 0.02 m2/s during the flood tide experiment. The diffusivity showed strong dependence (R2 > 0.9) on the horizontal mean velocity within the channel. Enhanced diffusivity caused by shear dispersion resulting from the interaction of large scale flow with the boundary geometries was observed. Turbulence within the shallow channel showed some similarities with the boundary layer flow which include consistency with slope of 5/3 predicted by Kolmogorov's similarity hypothesis within the inertial subrange. The diffusivities scale locally by 4/3 power law following Okubo's scaling and the length scale scales as 3/2 power law of the time scale. The diffusivity scaling herein suggests that the modelling of small scale mixing within tidal shallow estuaries can be approached from classical turbulence scaling upon identifying pertinent parameters.

Persistence and Non-target Impact of Imazapyr Associated with Smooth Cordgrass Control in an Estuary

The herbicide (±-2-[4,5-dihydro-4-methyl-4-(1-methylethyl)- 5-oxo-1 H -imidazol-2-yl]-3-pyridinecarboxylic acid (imazapyr) has shown potential to control smooth cordgrass (Spartina alterniflora Loisel), a noxious weed in many estuaries throughout the world. Research was conducted under tidal estuary conditions in Willapa Bay, Washington, to determine imazapyr’s persistence and aquatic risk and impact to non-target estuary species. Persistence of imazapyr in water and sediment followed an exponential decay.(PDF has 6 pages.)