Effects of Great Barrier Reef Degradation on Recreational Demand: A Contingent Behaviour Approach

Degradation of coral reefs may affect the number of tourists visiting the reef and, consequently, the economic sectors that rely on healthy reefs for their income generation. A Contingent Behaviour approach is used to estimate the effect of reef degradation on demand for recreational dive and snorkel trips, for a case study of the Great Barrier Reef (GBR) in Australia. We assessed how reef degradation affects GBR tourism and to what extent reef-trip demand depends on the visitors’ socio-economic characteristics. A count data model is developed, and results indicate that an average visitor would undertake about 60% less reef trips per year given a combined 80%, 30% and 70% decrease in coral cover, coral diversity and fish diversity, respectively. This corresponds to a decrease in tourism expenditure for reef trips to the Great Barrier Reef Marine Park of about A$ 136 million per year.Coral Reef, Recreation, Contingent Behaviour Model, Count Data Models

Designing a Decision Support System for Marine Reserves Management: An Economic Analysis for the Dutch North Sea

In this paper we discuss how a Decision Support System (DSS) for managing the marine environment can be set up. We use the Driving force-Pressure-State-Impact-Respond (DPSIR) framework to analyze which are the major driving forces impacting upon the marine environment in the North Sea. Moreover, a number of potential responses are identified. Furthermore, a preliminary and simplified optimization model has been set up and can be used in a DSS to decide on the best location of marine reserves for the protection of species. The model is based on a bio-economic metapopulation model that can be used to decide which parts of the sea should be opened for fisheries and which should be protected as marine reserve. It accounts for the dispersal of fish and considers both the economic returns from fisheries and the ecological value of marine biodiversity. A number of suggestions are given on how to extend and improve the DSS.Decision Support System, Marine Biodiversity Conservation, DPSIR Framework, Bioeconomic Modeling, North Sea

Effects of Great Barrier Reef Degradation on Recreational Demand: A Contingent Behaviour Approach

Agricultural run-off from the Great Barrier Reef catchment area may cause degradation of coral reefs, affecting the tourism sector that relies on healthy reefs for its income generation. A Contingent Behaviour approach is used to determine the effect of reef degradation on demand for recreational dive and snorkel trips, for a case study of the Great Barrier Reef (GBR) in Australia. We assessed how reef degradation affects GBR tourism and to what extent reef-trip demand depends on the visitors' socio-economic characteristics. A count data model is developed, and results indicate that an average visitor would undertake about 60% less trips to the GBR per year, given a combined 80%, 30% and 70% decrease in coral cover, coral diversity and fish diversity, respectively. This corresponds to a decrease in tourism expenditure for reef trips in the Great Barrier Reef Marine Park area of about A$ 136 million per year.Coral reef, Recreation, Contingent Behaviour model, Count data models, Resource /Energy Economics and Policy, Q26, Q51, Q57,

Biological control of invasive plant species: stochastic economic analysis

We analysed to what extent the stochastic effects of two biological control agents (i.e. weevils and mycoherbicides) affect the optimal choice of Californian thistle control. A stochastic, dynamic optimisation model was set up to analyse strategies that maximise the expected net present values. We analysed the cost-effective strategies to control the thistle for deterministic and stochastic cases. Results show that the stochasticity of the efficacy of weevils does not affect the optimal strategy. Compared to the deterministic case, however, mycoherbicides will be introduced at a higher level of weed density if we take the stochastic effect of mycoherbicides into account.Stochastic, Optimisation, Biological control, Californian thistle, Economics.,

Verkassen? Maatschappelijke kosten en baten van het verplaatsen van tuinbouw ten behoeve van woningbouw.

Het bouwen van woningen in de Bollenstreek is maatschappelijk rendabel als de bollenteelt geleidelijk wordt verplaatst. Woningbouw in het Westland is mogelijk rendabel als het om extra woningen gaat. Dat blijkt uit een kengetallen kosten-batenanalyse (KKBA) van een toekomst waarin in 2040 een kwart van de huidige ‘greenports’ wordt gebruikt voor woningbouw. Het gaat bij de verplaatsing in het Westland om 1000 hectare tuinbouwgrond en in de Bollenstreek om 500 hectare. Voor de kosten en baten is van belang wat er gebeurt met de tuinbouwactiviteiten. Daarom zijn drie beleidsalternatieven onderzocht: 1. Er wordt elders binnen de Randstad ruimte voor tuinbouw gecreëerd; 2. Er wordt buiten de Randstad ruimte gecreëerd; 3. Er wordt geen extra ruimte gecreëerd en er moet gebruik worden gemaakt van al beschikbare ruimte

Tripodal 1,3,5-benzenetricarboxamide ligand with dipicolinic acid units and its binding with Eu(III) ions

The synthesis and characterisation of tripodal ligand 1 containing 1,3,5-benzenetricarboxamide core and diethyl 4-(phenylethynyl)pyridine-2,6-dicarboxylate is described. The crystal structure of the intermediate tripodal molecule 7 exhibits an unusual staggered hydrogen-bonded chain motif instead of the anticipated helical assembly. We studied the basic photophysical properties of 1 in solvents of various polarity including CH3OH, CH3CN, DMSO, and CHCl3. The self-assembly experiments between 1 and Eu(CF3SO3)3⋅6H2O confirmed the formation of metal-ligand self-assembly species in the solution of CH3CN. It was also shown that the excitation of the Eu(III)-centred emission in such species occurred through the energy transfer from the ligand acting as an antenna to the metal centre. The binding constant values were evaluated using the nonlinear regression analysis software SPECFIT®, and their values correspond to those previously observed for the assemblies between 2,6-dipicolinic acid derivatives and lanthanide ions. This work describes the synthesis of tripodal 1,3,5-benzenetricarboxamide ligand with dipicolinic acid units and its binding with Eu(III) ions in solution. The photophysical properties of the target tripodal ligand were studied in solvents of various polarity. The self-assembly experiments between the ligand and Eu(III) ions in solution confirmed the formation of luminescent metal-ligand self-assembly species.</p

A simple model to quantitatively account for periodic outbreaks of the measles in the Dutch Bible Belt

In the Netherlands there has been nationwide vaccination against the measles since 1976. However, in small clustered communities of orthodox Protestants there is widespread refusal of the vaccine. After 1976, three large outbreaks with about 3000 reported cases of the measles have occurred among these orthodox Protestants. The outbreaks appear to occur about every twelve years. We show how a simple Kermack-McKendrick-like model can quantitatively account for the periodic outbreaks. Approximate analytic formulae to connect the period, size, and outbreak duration are derived. With an enhanced model we take the latency period in account. We also expand the model to follow how different age groups are affected. Like other researchers using other methods, we conclude that large scale underreporting of the disease must occur