Salmon aquaculture and coastal ecosystem health in Chile: Analysis of regulations,environmental impacts and bioremediation systems

In 2007 salmon, mollusk and seaweed aquaculture production in Chile totaled 904 thousand tonnes, making the nation the leading marine aquaculture producer in the western world. Salmonids grown in open cage net pens account for over 73% of the production. This review summarizes the current status of Chilean aquaculture and proposes the establishment of new regulations and monitoring programmes that encourage and accommodate emerging bioremediation technologies. In contrast to a rapidly expanding, well-financed and technologically advanced industry, the regulatory structure in Chile is outdated and based on insufficient science. The number of publications on the environmental impacts of salmon aquaculture in Chile is low relative to its production level. Nevertheless, the impacts of organic and inorganic waste on benthic communities, pelagic organisms and bird populations are documented. The technology to reduce these impacts using integrated multi-trophic aquaculture (IMTA) strategies exists, but has not been implemented at commercial scales. We call on the government and industry to support the creation of a well-financed and politically independent agency responsible for developing and enforcing science-based environmental regulations in Chile. The agency's immediate goal should be to fund research required to develop a transparent, ecosystem-based regulatory framework that promotes IMTA. Monitoring programs and licensing procedures must consider the impacts of individual sites and the cumulative impacts from multiple sites across a wide range of spatial scales. Before such changes are realized, environmental threats and human health risks will remain unacceptably high and salmon farming in Chile will not meet any reasonable definition of sustainability.     

Improving the recreational value of Ireland's coastal resources: A contingent behavioural application

This paper measures willingness to pay (WTP) for public access to additional beach area and trail improvements to a coastal recreational site in the west of Ireland. The Contingent Behaviour model is used to measure the increased number of trips associated with improved public access using a connecting trail between two beach areas along a stretch of Irish coastline. Results show that improving access through the use of the connecting trail increases consumer surplus by €111.15 per person per annum. It is argued that in designing new regulation such as Marine Protected Areas (MPAs) for the management of Ireland's coastline, an understanding of the values the Irish public place on coastal recreational access will be important to manage the resource in a sustainable manner.     

Social acceptability of marine aquaculture: The use of survey-based methods for eliciting public and stakeholder preferences

The social acceptability of aquaculture is linked to its perceived environmental impact, and this clearly poses a challenge to policy makers in deciding what weight to attach to such a concern within a governance framework for the industry. Using salmon farming in Scotland as a case study, we have developed a survey-based approach to evaluating public and stakeholder attitudes towards the environmental performance of aquaculture. The survey of the general public finds marked regional variations in attitudes towards salmon farming, while the results of the stakeholder survey raise issues over how far the preferences of particular interest groups are truly representative of the community as a whole.     

Solutions to blue carbon emissions: Shrimp cultivation,mangrove deforestation and climate change in coastal Bangladesh

In Bangladesh, export-oriented shrimp farming is one of the most important sectors of the national economy. However, shrimp farming in coastal Bangladesh has devastating effects on mangrove forests. Mangroves are the most carbon-rich forests in the tropics, and blue carbon (i.e., carbon in coastal and marine ecosystems) emissions from mangrove deforestation due to shrimp cultivation are accumulating. These anthropogenic carbon emissions are the dominant cause of climate change, which in turn affect shrimp cultivation. Some adaptation strategies including Integrated Multi-Trophic Aquaculture (IMTA), mangrove restoration, and Reducing Emissions from Deforestation and forest Degradation (REDD+) could help to reduce blue carbon emissions. Translocation of shrimp culture from mangroves to open-water IMTA and restoration of habitats could reduce blue carbon emissions, which in turn would increase blue carbon sequestration. Mangrove restoration by the REDD+ program also has the potential to conserve mangroves for resilience to climate change. However, institutional support is needed to implement the proposed adaptation strategies.     

基于空间距离效应的青岛市浒苔治理支付意愿研究

支付意愿的空间属性是影响环境物品估值效度的主要因素之一,忽略对空间距离的考量可能导致最终资源环境物品或服务的货币估值产生偏差。文章以青岛市海域浒苔灾害为研究对象,使用条件价值评估法,构建支付意愿函数模型,测算受访者距青岛市海边的距离,探索浒苔治理支付意愿是否存在距离衰减现象;通过划分不同的距离区,测算不同距离区内公众浒苔治理支付意愿,最终汇总得出浒苔治理带来的经济价值。研究结果显示：公众浒苔治理支付意愿“距离衰减”效应明显,距离海边较近的公众倾向于为治理浒苔支付较高的金额;青岛市浒苔治理总经济价值为9.84亿元/a;不考虑距离衰减效应最终导致浒苔治理经济价值的高估达27.03%。研究结论可为空间尺度上的非市场价值评估提供新的研究思路和科学参考,不仅提高了条件价值评估法估值结果的有效性,也提供了更加精准的青岛市浒苔治理经济价值估值。     

Effects of wild fish and motile epibenthic invertebrates on the benthos below an open water fish farm

A manipulative caging experiment was carried out to evaluate the role of wild fish and motile epibenthic invertebrates on the benthic system influenced by an open water fish farm. Chemical and biological parameters of the sediment were measured as indicators of the ecological benthic status. The combination of wild fish and currents notably lowered aquaculture waste sedimentation below the fish farm. The limited waste sedimentation rate could have limited the scavenger and predation activity of wild fish on the benthos, whose role may be taken over by motile epibenthic invertebrates. The interaction of these motile epibenthic invertebrates with the sediment differed from that observed with fish. The motile epibenthic invertebrates led to more reduced conditions with lower redox values, significantly decreased the number of species of macrofaunal benthic assemblages and significantly modified macrofaunal benthic assemblages. Therefore, epibenthic invertebrates do not seem to have an ameliorative effect on the benthic status produced by fish farming. Since the effects of epibenthic species on the benthic system can greatly vary according to their identity, further experiments should be performed to better understand the drivers that influence the epibenthic species identity that modulate the benthic system affected by fish farming.     

A GIS modelling framework to evaluate marine spatial planning scenarios: Co-location of offshore wind farms and aquaculture in the German EEZ

The concept of co-location of marine areas receives an increased significance in the light of sustainable development in the already heavily used offshore marine realm. Within this study, different spatial co-location scenarios for the coupling of offshore aquacultures and wind farms are evaluated in order to support efficient and sustainable marine spatial management strategies. A Geographic Information System (GIS) and multi-criteria evaluation (MCE) techniques were combined to index suitable co-sites in the German exclusive economic zone of the North Sea. The MCE was based on criteria such as temperature, salinity or oxygen. In total, 13 possible aquaculture candidates (seaweed, bivalves, fish and crustaceans) were selected for the scenario configuration. The GIS modelling framework proved to be powerful in defining potential co-location sites. The aquaculture candidate oarweed (Laminaria digitata) revealed the highest suitability scores at 10–20 m depth from April to June, followed by haddock (Melanogrammus aeglefinus) at 20–30 m depth and dulse (Palmaria palmata) and Sea belt (Saccharina latissima) at 0–10 m depth between April and June. In summary, results showed several wind farms were de facto suitable sites for aquaculture since they exhibited high suitability scores for Integrated Multi-Trophic Aquaculture (IMTA) systems combining fish species, bivalves and seaweeds. The present results illustrate how synergies may be realised between competing needs of both offshore wind energy and offshore IMTA in the German EEZ of the North Sea. This might offer guidance to stakeholders and assist decision-makers in determining the most suitable sites for pilot projects using IMTA techniques.     

Analysis of the economic benefits associated with the recovery of threatened marine mammal species in the Canadian St. Lawrence Estuary

This paper examines Canadians' willingness to pay to recover the populations of three marine mammal species found in the St Lawrence Estuary. The valuation approach utilized a stated preference tool that is somewhat a hybrid between contingent valuation and a choice experiment with multiple species recovery program options and choices framed as referenda. Program options involved the use of a marine protected area and restrictions on whale watching and shipping industries. The estimated willingness to pay (WTP) for different levels of marine mammal recovery ranged from $77 to $229 per year per household and varied according to the species affected and the recovery program effort. A series of tests revealed that people would be willing to pay more for programs that contribute to greater increases in marine mammal populations, but the additional value of programs that improve a species status beyond the “at risk” threshold is relatively small.     

Diversity in narratives to green the Norwegian salmon farming industry

Despite being an economic success and generating considerable profit, the Norwegian salmon farming industry face environmental challenges that need to be solved. Since 2014, all new licenses to farm salmon are labelled either “light-green”, dark-green” or “development licenses”. The industry is nevertheless characterized by the open net-pen as a hegemonic technology, and is susceptible to both cognitive and political lock-in. In the article, it is defined which narratives on “greening criteria” that are dominant and an analysis is presented on how narratives influence new licenses for salmon farming. The data is derived from 52 qualitative interviews and a broad qualitative analysis of trends and debates in the industry. From the perspective of evolutionary economic geography and the sub-concept path dependency, narratives on greening criteria for future salmon farming are divided in three categories: path extension, modest path renewal and strong path renewal. The findings reveal that although most licenses are linked to mere path extension, development licenses might disrupt this trend.     

三沙湾盐田港养殖海域沉积物中的有机碳、氮和磷

于2012年8月(夏季)、11月(秋季)和2013年2月(冬季)、5月(春季)共4个航次对三沙湾盐田港养殖海域表层沉积物组成成分及其变化趋势进行调查分析,并采用单因子污染指数(Pi)对沉积物质量进行评价。结果表明不同功能区沉积物中有机氮(TN)、总磷(TP)和有机碳(OC)含量差异显著(P0.05),TN和TP含量4季变化范围分别是0.15~1.39 g/kg和0.11~1.08 g/kg,平均值分别为(0.89±0.36)g/kg和(0.56±0.26)g/kg。OC含量在1.00~14.71 g/kg之间,平均值为(8.26±3.78)g/kg。各站位沉积物中TN污染指数4季变化范围为0.25~2.53,4季超标率分别为67%、81%、80%和90%;各站位TP污染指数4季变化范围为0.18~2.63,4个季节超标率分别为35%、80%、40%和51%;各季节OC含量均未超标;OC/N原子比全年变化范围在8.4~10.3之间,平均值为8.9±0.6。较弱的水流交换条件和海水养殖,特别是海水网箱养殖,是造成沉积物污染的主要原因,开展多营养层次的综合养殖模式是促进盐田港海水养殖可持续发展的有效途径。     

Changing balance of fish production in Scotland

The last two decades have seen substantial changes in fish production in Scotland, with the rise of shell fish and farmed salmon to be important production sectors beside the established sectors of demersal and pelagic fish. In conventional fisheries conservation programmes based on scientific advice have become a permanent part of the organisation, while the expansion of fish farming has been essentially founded on systematic scientific investigation. The changing pattern and balance of production has been functionally related to developments in processing, transport and marketing of fish. Central to this has been the expansion of fish freezing, which maintains food value to the best effect for the consumer.     

海水网箱养殖的环境管理

越来越多的海水网箱养殖给近岸海洋生态环境保护带来了巨大的压力,也对近岸海洋生态系统的结构与功能造成了一定的影响。根据我国海水网箱养殖的发展状况,分别从行政管理制度、环境规划、养殖管理和技术措施等方面对养殖场的环境管理进行了分析。对比国外在网箱养殖过程中的环境管理措施与经验,探讨了减少网箱养殖给海洋环境带来的污染的措施和饲料配额制度的可行性与必要性。在将来,环境管理会成为生产管理的重要部分,我们的研究结果可为发展中的中国海水鱼类养殖管理提供参考。     

Searching for sustainability in aquaculture: An investigation into the economic prospects for an integrated salmon–mussel production system

The pollution effects of cage aquaculture represent an external cost to society, and the challenge for environmental economists has been to estimate the magnitude of these costs and to suggest ways in which they can be mitigated or ‘internalised’. One possible mitigation strategy involves the development of integrated production systems based on polyculture, and this paper examines the financial viability of such a system that integrates the farming of salmon and mussels. The results demonstrate the commercial potential of an integrated salmon–mussel production system under present market conditions, but highlight the critical role played by future price trends.     

Can farmed salmon production keep growing?

Time series data was used to compute 5-year moving average rates of growth in salmon aquaculture production over time for four of the world's leading salmon farming countries, and globally. This analysis reveals a decline of 1.2% per year in global farmed salmon production since it peaked in 1966. Analysis of production data for all farmed finfish, both marine and freshwater, shows a decline of 0.34% per year in the growth rate from the peak year. These results have implications for global fisheries policy because it means that it is unlikely that aquaculture alone can meet the fish protein needs of humans.     

Application of laser ablation ICPMS to trace the environmental history of chum salmon Oncorhynchus keta

Trace element levels in otoliths of chum salmon Oncorhynchus keta were examined by means of laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS). A close linear relationship in the Sr:Ca ratios between EPMA (X-ray analysis with an electron microprobe) and LA-ICPMS analyses was found (p<0.0001), suggesting that the latter technique could be used to separate the marine and freshwater life phases. Mg:Ca, Cr:Ca, Zn:Ca and Ba:Ca ratios in either the core region or the oceanic growth zone of the otoliths varied among sites. These differences suggest that elemental compositions may reflect environmental variability among spawning (breeding) or habitat sites. Thus, those element ratios demonstrate the potential to be used to distinguish between fish spawning (breeding) sites and habitats for this species of salmon.     

The non-consumptive (tourism) ‘value’ of marine species in the Northern section of the Great Barrier Reef

This paper uses the Kristrom (logit) spike model to analyse contingent valuation (payment card) data from a study of 2180 domestic and international visitors taking reef trips to the Northern section of the Great Barrier Reef. It investigates: (a) their willingness to pay for a “100% guaranteed sighting” of several different marine species; and (b) the sensitivity of final estimates to various methodological issues. It finds that final estimates are particularly sensitive to questionnaire design, but that the ranking of species (from most to least ‘valued’) is robust across a range of methodological specifications. The most valued groups of species were (in order): whales and dolphins; sharks and rays; ‘variety’; marine turtles; and finally large fish. Evidently, whale watching is not the only potentially lucrative source of tourism revenue; other marine species may be similarly appealing. These potential revenues need to be considered when making decisions about whether or not to conserve marine species.     

Valuing coastal water quality: Adelaide,South Australia metropolitan area

Coastal environments are increasingly under threat from multiple stressors and pressure from human activities across the land-sea interface. Managing these pressures from people requires, more than ever, understanding what is at stake in terms of the benefits and values associated with coastal waters. This article presents the results of a choice experiment which was designed to elicit society׳s willingness to pay in the context of economic and environmental trade-offs people to improve coastal water quality. The study site is a coastal Australian city, Adelaide, South Australia. The city discharges a large proportion of its stormwater and treated wastewater to the coastal waters of Gulf St Vincent. Willingness to pay for a package of improvements to urban water management is considerable. A mix of projects that restores 25 days per year of water clarity, seagrass area from 60% to 70% of the original area and five reef areas is worth $AUS67.1 M to households in the Adelaide metropolitan area. The results can inform public policy discussions including the cost-benefit analysis of different water management strategies including investments in urban infrastructure.     

Access to marine parks: A comparative study in willingness to pay

Marine parks worldwide are under assault from illegal fishing, pollution and a burgeoning tourism industry. However, their principal mission of environmental protection and conservation is too often hampered by lack of funds. In recent years a number of studies have been done on the willingness of users to pay entrance fees to fund marine park management particularly those where coral reefs occur. In this analysis, we examine 18 such reports from which we conclude that there is overwhelming public approval to pay for entry to marine parks, with all studies indicating a general acceptance for the introduction of fees or an increase in those where charges already exist. Factors that positively influence this include visitors income, level of education, environmental awareness, residency and desire to provide a legacy to future generations. However, there are also aspects that deter including trust in the fee collection agency and openness in how the money is spent. This analysis endeavours to highlight those aspects that positively influence users of marine parks to contribute willingly to their management and help close the funding gap that confronts so many.