Household susceptibility to hydrological change in the Lower Mekong Basin

The hydrological conditions of the Lower Mekong Basin support a multitude of ecosystem services. Processes that influence water flow in the Mekong River will thus have implications for the tens of millions of people whose livelihoods depend on these services. This study presents an assessment of livelihood susceptibility to hydrological change in the Lower Mekong Basin. Using an index‐based approach, susceptibility scores were calculated for 2,703 households. Using those scores, we compared average household susceptibility across the basin, among countries and among eco‐zones. Due to their greater livelihood dependency on water‐related activities, mean household susceptibility was higher in Vietnam than in Cambodia, Laos, or Thailand. Households in Northern Laos also had high susceptibility, which was attributed to their low adaptive capacity. The findings suggest that policies aimed at reducing vulnerability to hydrological change in the Lower Mekong Basin should account for geographic context. Further, they highlight how policies may be able to strategically target the most susceptible households, but that poorly designed policies have the potential to exacerbate vulnerability. In the face of high uncertainty surrounding hydrological change in the Lower Mekong Basin, our assessment of susceptibility should help inform precautionary water management policies and provide baseline information needed for more comprehensive vulnerability assessments.     

Environmental change and fishery management in the northern Persian Gulf

Approximately 52% of the 380,000 tons of fish landings in Iran come from the northern Persian Gulf, with a total of 108,000 fishermen and 8900 fishing vessels (2003 data). The fishery in the region is very important for the local economy, but the major problems facing the Iranian fisheries are an uncertain availability of fish and over-fishing. The Persian Gulf is a sensitive marine ecosystem. The Gulf is a partially enclosed sea with an average depth of 35 metres and replacement of waters take some three to five years. Environmental factors have a major effect on fish stocks and fisheries in such a sensitive ecosystem. This study examines the influence of environmental changes in water temperature, rainfall, wind and sea level pressure on fish stocks in the northern Persian Gulf and estimates the maximum sustainable yields for fisheries management. Multivariate data and surplus production bio-economic models with environmental parameters are used to determine optimal harvest and forecasting. The study found that rainfall, water temperature and wind had significant positive effects whereas sea level pressure had a negative effect on the fisheries in the northern Persian Gulf. It is concluded that environmental parameters should be monitored concurrently with the fisheries to allow a greater understanding for fisheries management in the Persian Gulf.     

通江湖泊的渔业意义及其资源管理对策

长江中、下游的江湖复合生态系统包含有河流和湖泊两个环境单元。其中的鱼类群落由河海洄游鱼类、江湖洄游鱼类、河流鱼类和定居性鱼类等４个生态类群组成,尤以江湖洄游鱼类对这一特殊的生态环境形成了良好的适应,因而种群数量繁盛,从渔业的角度看,水利工程造成的江湖阻隔削弱了通江湖泊的生态功能,成为导致鱼类资源下降和种类结构改变的主要原因之一。当前应从控制捕捞、人工增殖和恢复生态环境结构等方面着手进行资源管理,确     

Demolish it and They Will Come: Estimating the Economic Impacts of Restoring a Recreational Fishery1

Abstract: This paper presents the results of an ex post survey of recreational anglers for the lower Kennebec River, post‐Edwards Dam removal. To the best of our knowledge, this study represents one of the first ex post analyses of fisheries restoration from dam removal. We find significant benefits have accrued to anglers using the restored fishery. Specifically, anglers are spending more to visit the fishery, a direct indication of the increased value anglers place on the improved fishery. Anglers are also willing to pay for increased angling opportunities on the river. These findings have policy implications for other privately owned dams that are currently undergoing relicensing and/or dam removal considerations. Our findings may also hold implications for fisheries that have deteriorated due to historic dam construction.     

A participatory decision making framework for artisanal fisheries collaborative governance: Insights from management committees in Chile

Fisheries management is increasingly transitioning towards collaborative governance. Collaborative systems depend on stakeholders’ capacity to design and implement legitimate and scientifically robust management plans within collective action arenas. Here we propose that collaborative governance outcomes, in fisheries management, will benefit from using structured participatory decision making frameworks that enhance deliberative thinking among stakeholders. We tested our approach in the artisanal fishery of Chile, an important producer of marine resources. Recently in 2013, Chile made important changes to fisheries policies by creating multi-sectorial management committees to manage de facto open access fishing areas. We applied a structured decision making framework to inform the restructuring of a management plan within a committee. As a result, we identified goals,objectives and indicators, including social, economic, biological and ecological dimensions; we explored tradeoffs, assessing the relative importance of the objectives; finally, we created scenarios and prioritized alternatives, reflecting on the interplay between self-regulation and government control. Members of the management committee were able to rationalize the different steps of the framework and identify ways forward which highlighted the importance of self-regulation in comparison to central authorities’ control. We concluded that structured decision making promotes spaces for rational analysis of alternatives costs and benefits. Promoting deliberative thinking in fisheries management can improve equity, legitimacy and sustainability of collaborative governance.     

Environment and development in the Republic of the Marshall Islands: Linking climate change with sustainable fisheries development

The Republic of the Marshall Islands (RMI) is a major custodian of one of the ocean's major natural resources: tuna. The commercial tuna fisheries sector is the most important economic sector in the RMI and is thus a substantial contributor to this tiny island nation's GDP. Tuna catch and its associated revenues has fluctuated in line with climatic events such as the El Niño/La Niña Southern Oscillation (ENSO) and, in the last decade, national fisheries development policies have begun to capitalize on the positive effects that ENSO warm events have had on the tuna populations. However, global warming is expected to have a significant impact on ENSO, and not necessarily in positive ways. This paper will focus on the relationship between environment and economic development in the RMI fisheries sector. In particular, the linkages between global warming and its effects on the tuna fisheries sector must be better understood and uncertainties accounted for so that impacts are appropriately addressed and integrated into sustainable fisheries development policies. Conclusions reached are that new fisheries development strategies that emphasize environmental‐based planning are required. The emerging ecosystem‐based approach to fisheries management is a start, as are the various international initiatives in furthering our understanding of the linkages between climate and ocean systems currently underway.     

Use of radar detectors to track attendance of albatrosses at fishing vessels

Despite international waters covering over 60% of the world's oceans, understanding of how fisheries in these regions shape ecosystem processes is surprisingly poor. Seabirds forage at fishing vessels, which has potentially deleterious effects for their population, but the extent of overlap and behavior in relation to ships is poorly known. Using novel biologging devices, which detect radar emissions and record the position of boats and seabirds, we measured the true extent of the overlap between seabirds and fishing vessels and generated estimates of the intensity of fishing and distribution of vessels in international waters. During breeding, wandering albatrosses (Diomedea exulans) from the Crozet Islands patrolled an area of over 10 million km² at distances up to 2500 km from the colony. Up to 79.5% of loggers attached to birds detected vessels. The extent of overlap between albatrosses and fisheries has widespread implications for bycatch risk in seabirds and reveals the areas of intense fishing throughout the ocean. We suggest that seabirds equipped with radar detectors are excellent monitors of the presence of vessels in the Southern Ocean and offer a new way to monitor the presence of illegal fisheries and to better understand the impact of fisheries on seabirds.     

Factors Mediating Co‐Occurrence of an Economically Valuable Introduced Fish and Its Native Frog Prey

Habitat characteristics mediate predator–prey coexistence in many ecological systems but are seldom considered in species introductions. When economically important introduced predators are stocked despite known negative impacts on native species, understanding the role of refuges, landscape configurations, and community interactions can inform habitat management plans. We measured these factors in basins with introduced trout (Salmonidae) and the Cascades frog (Rana cascadae) to determine, which are responsible for observed patterns of co‐occurrence of this economically important predator and its native prey. Large, vegetated shallows were strongly correlated to co‐occurrence, and R. cascadae larvae occur in shallower water when fish are present, presumably to escape predation. The number of nearby breeding sites of R. cascadae was also correlated to co‐occurrence, but only when the western toad (Anaxyrus boreas) was present. Because A. boreas larvae are unpalatable to fish and resemble R. cascadae, they may provide protection from trout via Batesian mimicry. Although rescue‐effect dispersal from nearby populations may maintain co‐occurrence, within‐lake factors proved more important for predicting co‐occurrence. Learning which factors allow co‐occurrence between economically important introduced species and their native prey enables managers to make better‐informed stocking decisions. Factores que Median la Co‐Ocurrencia de un Pez Introducido con Valor Económico y su Presa, una Rana Nativa     

Efficient and equitable design of marine protected areas in Fiji through inclusion of stakeholder‐specific objectives in conservation planning

The efficacy of protected areas varies, partly because socioeconomic factors are not sufficiently considered in planning and management. Although integrating socioeconomic factors into systematic conservation planning is increasingly advocated, research is needed to progress from recognition of these factors to incorporating them effectively in spatial prioritization of protected areas. We evaluated 2 key aspects of incorporating socioeconomic factors into spatial prioritization: treatment of socioeconomic factors as costs or objectives and treatment of stakeholders as a single group or multiple groups. Using as a case study the design of a system of no‐take marine protected areas (MPAs) in Kubulau, Fiji, we assessed how these aspects affected the configuration of no‐take MPAs in terms of trade‐offs between biodiversity objectives, fisheries objectives, and equity in catch losses among fisher stakeholder groups. The achievement of fisheries objectives and equity tended to trade‐off concavely with increasing biodiversity objectives, indicating that it is possible to achieve low to mid‐range biodiversity objectives with relatively small losses to fisheries and equity. Importantly, the extent of trade‐offs depended on the method used to incorporate socioeconomic data and was least severe when objectives were set for each fisher stakeholder group explicitly. We found that using different methods to incorporate socioeconomic factors that require similar data and expertise can result in plans with very different impacts on local stakeholders.     

Understanding non-compliance in small-scale fisheries: Shark fishing in Myanmar’s Myeik Archipelago

Achieving fisheries compliance is challenging in contexts where enforcement capacity is limited and the incentives for rule-breaking are strong. This challenge is exemplified in Myanmar, where an active shark fishery exists despite a nationwide ban on targeted shark fishing. We used the Kipling method (5W1H) to gather a complete story of non-compliance in five small-scale fishing communities in the Myeik Archipelago. Among 144 fishers surveyed, 49% were aware of the nationwide ban. Shark fishers (24%) tended to be younger individuals who did not own a boat and perceived shark fishing to be prevalent. Compliant fishers were motivated by a fear of sharks and lack of capacity (equipment, knowledge), whereas food and income were cited as key motivations for non-compliance. The results of our study emphasize that in resource-dependent communities, improving compliance for effective shark conservation may require addressing broader issues of poverty, food security and the lack of alternatives.Electronic supplementary materialThe online version of this article (10.1007/s13280-020-01400-1) contains supplementary material, which is available to authorized users.