Sudden disruptions, or shocks, to food production can adversely impact access to and trade of food commodities. Seafood is the most traded food commodity and is globally important to human nutrition. The seafood production and trade system is exposed to a variety of disruptions including fishery collapses, natural disasters, oil spills, policy changes, and aquaculture disease outbreaks, aquafeed resource access and price spikes. The patterns and trends of these shocks to fisheries and aquaculture are poorly characterized and this limits the ability to generalize or predict responses to political, economic, and environmental changes. We applied a statistical shock detection approach to historic fisheries and aquaculture data to identify shocks over the period 1976–2011. A complementary case study approach was used to identify possible key social and political dynamics related to these shocks. The lack of a trend in the frequency or magnitude of the identified shocks and the range of identified causes suggest shocks are a common feature of these systems which occur due to a variety, and often multiple and simultaneous, causes. Shocks occurred most frequently in the Caribbean and Central America, the Middle East and North Africa, and South America, while the largest magnitude shocks occurred in Asia, Europe, and Africa. Shocks also occurred more frequently in aquaculture systems than in capture systems, particularly in recent years. In response to shocks, countries tend to increase imports and experience decreases in supply. The specific combination of changes in trade and supply are context specific, which is highlighted through four case studies. Historical examples of shocks considered in this study can inform policy for responding to shocks and identify potential risks and opportunities to build resilience in the global food system.
Fisheries and Fisheries Management
Coastal hypoxia (dissolved oxygen ≤ 2 mg/L) is a growing problem worldwide that threatens marine ecosystem services, but little is known about economic effects on fisheries. Here, we provide evidence that hypoxia causes economic impacts on a major fishery. Ecological studies of hypoxia and marine fauna suggest multiple mechanisms through which hypoxia can skew a population’s size distribution toward smaller individuals. These mechanisms produce sharp predictions about changes in seafood markets. Hypoxia is hypothesized to decrease the quantity of large shrimp relative to small shrimp and increase the price of large shrimp relative to small shrimp. We test these hypotheses using time series of size-based prices. Naive quantity-based models using treatment/control comparisons in hypoxic and nonhypoxic areas produce null results, but we find strong evidence of the hypothesized effects in the relative prices: Hypoxia increases the relative price of large shrimp compared with small shrimp. The effects of fuel prices provide supporting evidence. Empirical models of fishing effort and bioeconomic simulations explain why quantifying effects of hypoxia on fisheries using quantity data has been inconclusive. Specifically, spatial-dynamic feedbacks across the natural system (the fish stock) and human system (the mobile fishing fleet) confound “treated” and “control” areas. Consequently, analyses of price data, which rely on a market counterfactual, are able to reveal effects of the ecological disturbance that are obscured in quantity data. Our results are an important step toward quantifying the economic value of reduced upstream nutrient loading in the Mississippi Basin and are broadly applicable to other coupled human-natural systems.
Food webs as representations of who eats whom are at the core of community ecology. Incorporation of tools from network theory enables assessment of how complex systems respond to natural and human-induced stressors, revealing how harvesting may degrade the properties and resilience of food webs. We present a comprehensive, coastal marine food web that includes 147 taxa cooccurring on shallow subtidal reefs along the highly productive and exploited Humboldt Current System of central Chile. This food web has connectance of 0.06, link density of 1204 and mean chain length of 4.3. The fractions of intermediate (76%), omnivorous (49%) and cannibalistic (8%) nodes are slightly lower than those observed in other marine food webs. Of the 147 nodes, 34 are harvested. Links to harvested nodes represented 50 to 100% of all trophic links of non-harvested nodes, illustrating the great impact that fishery pressure can have on the food web. The food web was compartmentalized into 5 sub-webs with high representation of harvested taxa. This structure changes if the fishery node is removed. Similarity analyses identified groups of harvested species with non-harvested nodes, suggesting that these tropho-equivalents could be sentinel species for the community-wide impacts of coastal fisheries. We conclude that fishing effects can be transmitted throughout the food web, with no compartments completely unaffected by harvesting. It is urgent to establish monitoring programs for community-wide effects of fisheries and assess whether resilience of these highly productive subtidal food webs has already been compromised, thereby identifying essential nodes that require stronger fisheries regulation.
The Mediterranean Sea has been defined “under siege” because of intense pressures from multiple human activities; yet there is still insufficient information on the cumulative impact of these stressors on the ecosystem and its resources. We evaluate how the historical (1950–2011) trends of various ecosystems groups/species have been impacted by changes in primary productivity (PP) combined with fishing pressure. We investigate the whole Mediterranean Sea using a food web modelling approach. Results indicate that both changes in PP and fishing pressure played an important role in driving species dynamics. Yet, PP was the strongest driver upon the Mediterranean Sea ecosystem. This highlights the importance of bottom-up processes in controlling the biological characteristics of the region. We observe a reduction in abundance of important fish species (~34%, including commercial and non-commercial) and top predators (~41%), and increases of the organisms at the bottom of the food web (~23%). Ecological indicators, such as community biomass, trophic levels, catch and diversity indicators, reflect such changes and show overall ecosystem degradation over time. Since climate change and fishing pressure are expected to intensify in the Mediterranean Sea, this study constitutes a baseline reference for stepping forward in assessing the future management of the basin.
Territorial use rights in fisheries (TURFs) paired with marine reserves (henceforth called "TURF-reserves") have been proposed as a viable management strategy to combat overfishing in many small-scale fisheries by combining the TURF benefits of exclusive access with the conservation, spillover, and resilience benefits of reserves. When appropriately designed and implemented, TURF- reserves can encourage stewardship and empower fishers to better manage their resources. While tools that assist spatial design in marine nearshore contexts exist, they are data intensive, require expertise in software operation, and often need Internet connection. We developed the TURF-Reserve Design Tool to assist spatial design in settings where these elements are not present by providing an easy-to-use decision support tool for small-scale fisheries contexts. This tool consists of a spatial bioeconomic model that allows managers to analyze the relative performance of TURF-reserve designs for a specific setting by assessing the relative ecological and economic outcomes of each design.
Territorial use rights in fisheries (TURFs) are becoming a widely promoted tool to enhance the sustainability of small-scale fisheries. In 1991, Chile established a national coastal TURF policy that gave legal authority to assign exclusive access rights to artisanal fisher organizations. In 2014, there were several hundred TURFs decreed to fisher organizations in different biophysical and socioeconomic settings. To date, research assessing TURF implementation has generally been based on a few case studies and have had mixed results. Here, we present results from a survey of 535 fishers from 55 different artisanal fisher organizations. The survey consisted of three open-ended questions that explore users' perceptions of the main problems, benefits, and improvements concerning assigned TURFs. We also sampled 55 presidents of artisanal fisher organizations to explore how they perceived the accomplishments of TURFs. Main key problems, as perceived by fishers, include increased costs associated with surveillance and poaching, and the variability and sometimes lack of financial returns. Despite strong price drops in exported species, TURFs have provided incentives for innovation and stewardship, and fishers are generally unwilling to relinquish them. In fact, fishers define TURF benefits in multiple dimensions, which include conservation/ ecological and territorial empowerment. Fisher presidents stress that although expectations of economic benefits have not been fully realized, territorial empowerment is a critical benefit. Through the analysis of fishers' perceptions on solutions to TURFs' problems, we highlight the development of stocking activities, combining TURFs with marine reserves, food traceability, and what we call BIO+ seafood— products that have associated biodiversity benefits.
Mean trophic level of fishery landings (MTL) is one of the most widely used biodiversity indicators to assess the impacts of fishing. Based on the landing data compiled by Food and Agriculture Organization combined with trophic information of relevant species in FishBase, we evaluated the status of marine fisheries from 1950 to 2010 for different coastal states in Pacific, Atlantic and Indian Oceans. We found that the phenomenon of “fishing down marine food webs” occurred in 43 states. Specifically, 27 states belonged to “fishing-through” pattern, and 16 states resulted from “fishing-down” scenario. The sign of recovery in MTL was common in the Pacific, Atlantic and Indian Oceans (occurred in 20 states), but was generally accompanied by significantly decreased catches of traditional low trophic level species. In particular, 11 states showed significant declining catches of lower trophic levels. The MTL-based assessment of “fishing down marine food webs” needs to be interpreted cautiously.
Belize recently committed to establishing territorial use rights in fisheries (TURFs), called "managed access" in Belize, throughout its territorial waters. While more remains to be done to ensure that scaling is successful, this national commitment and the design of a national system of managed access areas are important milestones in the expansion of rights-based fishery management in Belize. Theoretical work and empirical studies have yielded principles for scaling conservation innovations, many of which were applied in Belize over 3 yrs to achieve these milestones. Two pilot sites were established in 2011 and encompassed varied ecological and social conditions to maximize learning applicable to scaling to diverse sites. Participatory processes were used to identify fishery management challenges as perceived by fishers, managers, and other stakeholders, and to build consensus on solutions. A scaling team consisting of fishers, scientists, non-governmental organizations, community-based organizations, and government representatives with dedicated resources for scaling was formed. Our case study suggests that scaling principles derived from theoretical considerations and empirical analysis have contributed to the scaling of managed access in Belize, which is expected to result in significant conservation, social, and economic benefits. This in turn suggests that these principles may be relatively robust and perhaps can be applied elsewhere to scale conservation initiatives. Our case study also suggests that careful consideration of new information and changing conditions accompanied by appropriate decisions and changes in tactics and strategy are important for successful scaling.
Territorial use rights in fisheries (TURFs) represent a form of spatial co-management to secure access rights for communities while simultaneously supporting marine conservation. In Ecuador, a TURF system emerged in many mangrove-associated fisheries after the government enacted legislation in 1999 favoring decentralized mangrove conservation. In communities where custodias (mangrove concessions) were implemented, members of local fishing associations have defined access privileges for certain fisheries within the boundaries of their concession. The present study explores the tradeoffs that emerged through the interaction between informal customary norms in fishing and the formal TURF system associated with custodias. Combining fishery data and ethnographic insights about Ecuador's fishery for mangrove cockles Anadara tuberculosa (G. B. Sowerby I, 1833) and Anadara similis (C. B. Adams, 1852), I evaluate outcomes of fisher empowerment, perceptions of success, fishery productivity, and tradeoffs. I argue that empowering fishers with stewardship rights is critical for successful TURFs in Ecuador. Custodias have strengthened access rights and created conditions that promote habitat health with implications for fishery productivity and economic benefits derived from larger catch and shell sizes. On the other hand, custodias limit access and fisher mobility, resulting in the reconfiguration of fishing space and displacement of independent fishers from their customary grounds. Moreover, secure access rights do not necessarily provide incentives for individuals to harvest shells according to the size regulations imposed by current policies. Understanding the benefits and limitations of this integrated approach to coastal management may provide valuable insights for other forms of spatially-explicit marine governance and fisheries co-management.
There is a growing interest in working with customary management (CM) systems to effectively manage benthic resources and small-scale fisheries. The underlying notion is that CM institution as territorial use rights in fisheries (TURFs) can be sufficiently adaptive and dynamic to create the local incentives that are necessary for promoting sustainable fishing practices and marine conservation more generally in a given region. This paper reviews the social opportunities and challenges of working with CM systems as a form of TURF, particularly in Oceania. A key conclusion is that policy makers and managers not only need to recognize natural interconnectivity in any one marine space, but also consider the social interconnectivity of stakeholders that covers customary TURFs. Only by recognizing and working with the existing social networks that overlay any given marine territory can the operational principles of CM (as reviewed in this paper) be effectively deployed for achieving some kind of bioeconomic efficiency and creating an equitable rights-based fisheries management system.