The ecological effects of tuna fish farms are largely undocumented. This study confirmed their high capacity to attract surrounding wild fish. The aggregation effect persisted year round, without detectable seasonal differences. Farm impact was restricted to close proximity of the sea cages, and was more prominent over the bottom than in the water column strata. Tuna fish farms proved to be high energy trophic resources, as indicated by the enhanced fitness status of two focal species, bogue and seabream. Under abundant food supply, seabream appear to allocate the majority of energy reserves to gonaddevelopment. Farm associated bogue had greater parasite loads, with no detrimental effect on fitness status. Overall, tuna fish farms can be regarded as population sources for aggregated wild fish, and under the no fishing conditions within the leasehold areas, can serve as functional marine protected areas.
Aquaculture, Seafood, and Food Security
Within the discussion around sustainable diets, seafood consumption is still a relatively neglected field. This article discusses relevant behaviours consumers can perform to consume seafood sustainably. The predictive power of intention, descriptive social norms, trust, awareness and pro-environmental attitudes are theoretically discussed and statistically tested across two studies in regards to (a) using sustainable seafood labels, and (b) using sustainable seafood guides. Data analysis (N1 = 309, N2 = 881 Norwegian adults) shows that intentions, social norms and trust predict seafood label use across studies. The variables predicting seafood guide use are less stable which might be due to this behaviour being performed by a very small fraction of consumers only. Causal relationships have been identified in study 2 by applying cross-lagged panel analyses between intentions, trust and social norms and seafood label use. Further causal relationships were found between intentions, trust and awareness and seafood guide use. A bidirectional relationship was confirmed between descriptive social norms and seafood guide use. Potential strategies to promote seafood label- and seafood guide use, are discussed based on these results.
The disease Heart and Skeletal Muscle Inflammation (HSMI) is causing substantial economic losses to the Norwegian salmon farming industry where the causative agent, piscine orthoreovirus (PRV), is reportedly spreading from farmed to wild Atlantic salmon (Salmo salar) with as yet undetermined impacts. To assess if PRV infection is epidemiologically linked between wild and farmed salmon in the eastern Pacific, wild Pacific salmon (Oncorhynchus sp.) from regions designated as high or low exposure to salmon farms and farmed Atlantic salmon reared in British Columbia (BC) were tested for PRV. The proportion of PRV infection in wild fish was related to exposure to salmon farms (p = 0.0097). PRV was detected in: 95% of farmed Atlantic salmon, 37–45% of wild salmon from regions highly exposed to salmon farms and 5% of wild salmon from the regions furthest from salmon farms. The proportion of PRV infection was also significantly lower (p = 0.0008) where wild salmon had been challenged by an arduous return migration into high-elevation spawning habitat. Inter-annual PRV infection declined in both wild and farmed salmon from 2012–2013 (p ≤ 0.002). These results suggest that PRV transfer is occurring from farmed Atlantic salmon to wild Pacific salmon, that infection in farmed salmon may be influencing infection rates in wild salmon, and that this may pose a risk of reduced fitness in wild salmon impacting their survival and reproduction.
Participatory management is widely recognised as a working method of paramount importance, based on the principles of knowledge sharing, accountability and legitimacy. Hence, it is broadly considered suitable for addressing issues related to the sustainable development of the seafood industry, and specifically, of the aquaculture system. A survey focused on the current EU regulatory framework was carried out to elicit stakeholders' preferences, knowledge and experience on key issues for the development of organic aquaculture, supported by science-based regulations. The survey was completed by 65 stakeholders belonging to several categories, and it was supported by the implementation of the Analytic Hierarchy Process method. Stakeholders' preferences were elicited on organic production methods and control systems, the quality of the environment and organic products, fish health and welfare. The views expressed by the participants revealed both competence and awareness, despite the complexity of the subject. Several ideas and useful suggestions emerged regarding unresolved technical issues. In addition, the need for a targeted communication strategy on the quality of organic aquaculture products and the necessity of fostering European/national programs to support the production and marketing of organic aquaculture products were highlighted.
Out of nearly 30,000 teleosts dwelling in our planet's water bodies, only hundreds of them are commercially exploited and prevail on the global food market. Yet, our estimates of the species actually underpinning global trade is severely hampered by inaccuracy and non-compliance in labelling and reporting. Here, we target ethnic food stores in two British cities (Liverpool and Manchester metropolitan areas), whose numbers are increasing throughout Europe, to examine accuracy of traceability information available to consumers. Despite the existence of thorough EU labelling regulations, we unveil a high level of non-compliance, with a diverse range of poorly-known fish species, often sold without any label or with erroneous information, as demonstrated by DNA barcoding. Results indicate that about 41% of the samples were mislabelled, in stark contrast with a recent study that, in 2015, found < 5% mislabelling in EU supermarkets and fishmongers. These results highlight that inspectors and governments might not be fully aware of the wide diversity of fish species traded, indicating the need for a stronger enforcement of the EU labelling legislations. Compliance with regulations is required not only to protect consumers, but also fish stocks, as for many of the species identified in this survey, population assessment is poor or lacking altogether.
As the levels of radioactivity in seafood have fallen back into the safe range, Fukushima fisheries are considering reopening. However, even if seafood from the Fukushima area were sufficiently safe to distribute to seafood markets, its value may be undermined because of the damage done to its reputation by the Fukushima disaster. We quantified consumers’ preferences for seafood from Fukushima and adjacent prefectures to examine the extent of the reputational damage to Fukushima seafood. We conducted a choice experiment to measure consumers’ willingness to pay for seafood from the Fukushima area. We also measured the impact of displaying ecolabels [Marine Stewardship Council (MSC) and Marine Eco-label Japan (MEL)] on Fukushima products. The results indicated that Fukushima products are considerably discounted compared with products displayed as domestic; even products from adjacent prefectures are substantially discounted. By contrast, consumers positively evaluated locally labeled products. We also found that demersal fish are discounted more than pelagic fish that inhabit the ocean surface off the shore of Fukushima.
Marine Spatial Planning (MSP) can offer significant benefits in terms of economic conservation strategies, optimizing spatial planning and minimizing the impact on the environment. In this paper, we focused on the application of multi-criteria evaluation (MCE) technique for co-locating offshore wind farms and open-water mussel cultivation. An index of co-location sustainability (SI) was developed based on the application of MCE technique constructed with physical and biological parameters on the basis of remote sensing data. The relevant physical factors considered were wind velocity, depth range, concerning the site location for energy production, and sea surface temperature anomaly. The biological variables used were Chlorofill-a (as a measurement of the productivity) and Particle Organic Carbon (POC) concentration, in order to assess their influence on the probable benefits and complete the requirements of this management framework. This SI can be easily implemented to do a first order selection of the most promising areas to be more specifically studied in a second order approach based on local field data
Wild stocks of Pacific salmonids have experienced sharp declines in abundance over the past century. Consequently, billions of fish are released each year for enhancing abundance and sustaining fisheries. However, the beneficial role of this widely used management practice is highly debated since fitness decrease of hatchery-origin fish in the wild has been documented. Artificial selection in hatcheries has often been invoked as the most likely explanation for reduced fitness, and most studies to date have focused on finding signatures of hatchery-induced selection at the DNA level. We tested an alternative hypothesis, that captive rearing induces epigenetic reprogramming, by comparing genome-wide patterns of methylation and variation at the DNA level in hatchery-reared coho salmon (Oncorhynchus kisutch) with those of their wild counterparts in two geographically distant rivers. We found a highly significant proportion of epigenetic variation explained by the rearing environment that was as high as the one explained by the river of origin. The differentially methylated regions show enrichment for biological functions that may affect the capacity of hatchery-born smolts to migrate successfully in the ocean. Shared epigenetic variation between hatchery-reared salmon provides evidence for parallel epigenetic modifications induced by hatchery rearing in the absence of genetic differentiation between hatchery and natural-origin fish for each river. This study highlights epigenetic modifications induced by captive rearing as a potential explanatory mechanism for reduced fitness in hatchery-reared salmon.
Aquaculture accounts for almost one-half of global fish consumption. Understanding the regional impact of climate fluctuations on aquaculture production thus is critical for the sustainability of this crucial food resource. The objective of this work was to understand the role of climate fluctuations and climate change in subtropical coastal estuarine environments within the context of aquaculture practices in Heʻeia Fishpond, Oʻahu Island, Hawaiʻi. To the best of our knowledge, this was the first study of climate effects on traditional aquaculture systems in the Hawaiian Islands. Data from adjacent weather stations were analyzed together with in situwater quality instrument deployments spanning a 12-year period (November 2004 –November 2016). We found correlations between two periods with extremely high fish mortality at Heʻeia Fishpond (May and October 2009) and slackening trade winds in the week preceding each mortality event, as well as surface water temperatures elevated 2–3°C higher than the background periods (March-December 2009). We posit that the lack of trade wind-driven surface water mixing enhanced surface heating and stratification of the water column, leading to hypoxic conditions and stress on fish populations, which had limited ability to move within net pen enclosures. Elevated water temperature and interruption of trade winds previously have been linked to the onset of El Niño in Hawaiʻi. Our results provide empirical evidence regarding El Niño effects on the coastal ocean, which can inform resource management efforts about potential impact of climate variation on aquaculture production. Finally, we provide recommendations for reducing the impact of warming events on fishponds, as these events are predicted to increase in magnitude and frequency as a consequence of global warming.
Aquaculture production of finfish has seen rapid growth in production volume and economic yield over the last decades, and is today a key provider of seafood. As the scale of production increases, so does the likelihood that the industry will face emerging biological, economic and social challenges that may influence the ability to maintain ethically sound, productive and environmentally friendly production of fish. It is therefore important that the industry aspires to monitor and control the effects of these challenges to avoid also upscaling potential problems when upscaling production. We introduce the Precision Fish Farming (PFF) concept whose aim is to apply control-engineering principles to fish production, thereby improving the farmer's ability to monitor, control and document biological processes in fish farms. By adapting several core principles from Precision Livestock Farming (PLF), and accounting for the boundary conditions and possibilities that are particular to farming operations in the aquatic environment, PFF will contribute to moving commercial aquaculture from the traditional experience-based to a knowledge-based production regime. This can only be achieved through increased use of emerging technologies and automated systems. We have also reviewed existing technological solutions that could represent important components in future PFF applications. To illustrate the potential of such applications, we have defined four case studies aimed at solving specific challenges related to biomass monitoring, control of feed delivery, parasite monitoring and management of crowding operations.