Wild populations of seahorses are threatened by overexploitation and the increasing black market to supply the trade of dried specimens for traditional Chinese medicine, religious rituals and other uses. Intensive aquaculture systems, available for seahorses, are developed for producing high-value specimens for marine aquariums, and thus, are not suitable to solve the real threat facing their conservation, which is the market of dried seahorses. Therefore, our aim was to describe opportunities and constraints to develop low-cost aquaculture of seahorses in cages in mangrove estuaries to foster a legal and more sustainable production chain. A comprehensive review in literature was performed followed by trials throughout one year in a sub-tropical mangrove estuary to observe the strengths and weakness of low-cost systems set up in mangroves. In these systems, seahorses should grow-out relying only on wild plankton and periphyton available in the estuary. We discuss that the production of seahorses in mangrove areas has many opportunities to increase environmental and social sustainability. Nonetheless, we also addressed the main constraints of this production that should be overcome to establish a reliable culture protocol, including the environmental instability of estuaries, net obstruction, predators and escapees.
Aquaculture, Seafood, and Food Security
As the world's population continues to grow, the way in which ocean industries interact with ecosystems will be key to supporting the longevity of food and social securities. Aquaculture is crucial to the future supply of seafood, but challenges associated with negative impacts could impede increased production, especially production that is efficient and safe for the environment. Using the typology established by The Economics of Ecosystems and Biodiversity Initiative, we describe how marine aquaculture could be influential in supporting ecosystem services beyond solely the production of goods, through provisioning services, regulating services, habitat or supporting services, and cultural services. The provision of these services will vary, depending on functional traits of culture species, biotic and abiotic characteristics of the surrounding environment, farm design, and operational standards. Increasing recognition, understanding, and accounting of ecosystem service provision by mariculture through innovative policies, financing, and certification schemes may incentivize active delivery of benefits and may enable effects at a greater scale
The general purpose of assessment is to provide decision-makers with the best valuable data, information, and predictions with which management decisions will be supported. Using case studies taken from four scientific projects and dealing with the management of marine bivalve resources, lessons learned allowed identifying some issues regarding assessment approaches. The selected projects also introduced methodological or institutional frameworks: ecosystem approach to aquaculture (EAA), system approach framework (SAF), marine spatial planning (MSP), and valuation of ecosystem services (ES).
The study on ecosystem services linked ES to marine habitats and identified ES availability and vulnerability to pressures. The results were displayed as maps of resulting potential services with qualitative metrics. The vulnerability value is an alternative to monetary valuation and, in addition to identifying the most suitable areas for each type of ES, this metric allows identifying the management strategies that will most probably maintain or affect each individual ES.
The MSP example focused on bivalve farming activity and accounted for several criteria: habitat suitability, growth performance, environmental and regulation constraints and presence of other activities. The ultimate endpoint of such an approach is a map with qualitative values stating whether a location is suitable or not, depending on the weight given to each criterion.
In the EAA case study, the indicator was defined by the growth performance of cultivated bivalves in different locations. This indicator is affected by distant factors – e.g. populations of marine organisms competing for the same food resource, nutrient inputs from rivers, time to renew water bodies under the action of tidal currents. The role and interactions of these factors were assessed with a dynamical ecosystem model.
Examples illustrate that the assessment is often multi-dimensional, and that multiple variables would interact and affect the response to management options. Therefore, the existence of trade-offs, the definition of the appropriate spatial scale and resolution, the temporal dynamics and the distant effects of factors are keys to a policy-relevant assessment. EA and SAF examples show the interest of developing models relating response to input variables and testing scenarios. Dynamic models would be preferred when the relationship between input and output variables may be masked by non-linear effects, delay of responses or differences of scales.
When decision-making requires economic methods, monetary values are often of poor significance, especially for those ecosystem services whose loss could mean the end of life, and appear to be a comfortable oversimplification of reality of socio-ecological systems which cannot be summarized in single numbers. Alternative methods, such as the ones proposed in the SAF and ES examples, would preferably consider institutional analysis or multicriteria assessment rather than single monetary values.
Case studies also highlighted that credibility of assessment tools benefit from the association of stakeholders at different stages, among which: identification of the most critical policy issues; definition of system characteristics including ecological, economical and regulation dimensions; definition of modelling scenarios to sort out the most effective management options; assessment of models and indicators outputs.
Although aquaculture sometimes lessens the negative effects of fishing by lowering the need to capture wild animals and plants, some aquaculture practices still require the exploitation of wild populations. A largely overlooked case is the use of wild populations to provide seed to sea farms. Mussel farming in Northwest Spain involve the capture of thousands of tons of young mussels (0.5–2 cm long) from the nearby rocky intertidal every year to supply floating rafts. Despite its volume, the impact of this activity on other sessile organisms remains unassessed. To fill this gap in our knowledge, we monthly monitored the sessile intertidal assemblage of five protected and six exploited sites during the closed season in 2016 following a nested sampling plan. Like the by-catch typical of other fisheries, harvesting young mussels for aquaculture was detrimental to the abundance and diversity of the associated sessile assemblage not directly targeted by this activity. Coverage and richness were also significantly lowered by the exploitation of mussel seed, and the community structure of protected and exploited sites was significantly different. These differences continued until the next open season, suggesting that the closed season was too short for the recovery of the associated non-target sessile assemblage. Given the size of the local mussel industry, the incomplete recovery along the closed season implies that mussel aquaculture must be putting a sustained pressure on a sizeable portion of the rocky intertidal of Northwest Spain.
The worlds’ oceans and seas have tremendous potential to contribute to the provision of food, feed, energy and natural resources. The emerging concepts of “Blue Growth” and “Blue Economy” have put the development of new marine industries on the political agenda. As marine industries expand, spatial interconnections and industry boundaries are being drawn and the potential for the combined use of marine space is being explored. The aim of this paper is to provide a single source document that summarizes the probable boundaries of marine growth industries, namely aquaculture; offshore wind energy with fixed foundations; floating offshore wind energy; tidal and wave energy; marine biotechnology, seabed mining; and tourism and recreation, based on depth and distance from the shore. This is an important first step in developing a single source document for marine industry boundaries that will help marine spatial planners and researchers develop innovative industry combinations to foster growth in the marine sector. This paper explores marine industry overlaps in four basins: European Atlantic, Baltic/North Sea, Mediterranean/Black Sea and the Caribbean/ Gulf of Mexico. By describing the geographical characteristics of different sea basins, this paper helps to focus marine governance strategies for stimulating combinations of marine industries towards the most promising areas. The methodology developed in this paper was also used to generate 72 country-specific maps and corresponding tables to support marine spatial planning processes at a national level.
This study explores the value chain structure and chain activities of the imported shellfish industry in China. Data were collected from face-to-face semi-structured interviews in Guangzhou (n = 30) and Shanghai (n = 23) and a face-to-face survey in Shanghai (n = 71). Data analysis employed both content and descriptive analyses. Results show that the value chain is composed of several important members including foreign exporters, Chinese importers, wholesalers, resellers and clearance companies. Business partnership is the main channel by which marketing information is gained by chain members. Relationships are quite stable among the chain members, with quality, price and credit items being the most important factors that influence chain relationships. It seems that imported shellfish from some developed countries (e.g. Canadian and U.S. lobsters) have reached a market saturation in China's first-tier cities (e.g. Guangzhou and Shanghai) and relevant chain members face fierce competition. E-commerce is still not mature enough as a tool for the marketing development of imported shellfish in China.
Peru is one of the world’s leading fishing nations and its seafood industry relies on the trade of a vast variety of aquatic resources, playing a key role in the country’s socio-economic development. DNA barcoding has become of paramount importance for systematics, conservation, and seafood traceability, complementing or even surpassing conventional identification methods when target organisms show similar morphology during the early life stages, have recently diverged, or have undergone processing. Aiming to increase our knowledge of the species diversity available across the Peruvian supply chain (from fish landing sites to markets and restaurants), we applied full and mini-barcoding approaches targeting three mitochondrial genes (COI, 16S, and 12S) and the control region to identify samples purchased at retailers from six departments along the north-central Peruvian coast. DNA barcodes from 131 samples were assigned to 55 species (plus five genus-level taxa) comprising 47 families, 24 orders, and six classes including Actinopterygii (45.03%), Chondrichthyes (36.64%), Bivalvia (6.87%), Cephalopoda (6.11%), Malacostraca (3.82%), and Gastropoda (1.53%). The identified samples included commercially important pelagic (anchovy, bonito, dolphinfish) and demersal (hake, smooth-hound, Peruvian rock seabass, croaker) fish species. Our results unveiled the marketing of protected and threatened species such as whale shark, Atlantic white marlin, smooth hammerhead (some specimens collected during closed season), shortfin mako, and pelagic thresher sharks. A total of 35 samples (26.72%) were mislabeled, including tilapia labeled as wild marine fish, dolphinfish and hake labeled as grouper, and different shark species sold as “smooth-hounds”. The present study highlights the necessity of implementing traceability and monitoring programs along the entire seafood supply chain using molecular tools to enhance sustainability efforts and ensure consumer choice.
A seafood fraud campaign was launched by an ocean conservation group to increase transparency in global seafood supply chains by enacting policies on full chain boat-to-plate traceability for all seafood sold in the U.S. As part of this campaign, online members of the group were recruited to document and collect commercial seafood samples as part of a large investigation of U.S. seafood mislabeling, specifically species substitution. Following an iterative project design including several rounds of pilot testing of sample preservation methods and outreach materials, 1058 of the more than 55,000 members solicited signed up to be a “seafood sleuth” and were mailed seafood testing kits, containing supplies to submit two fish samples of their choice. On average, 33.4% (353/1058) of these citizen scientists in 11 metropolitan areas returned kits that contained 631 samples, or nearly half of the 1263 samples collected in the overall study. Assessment of the quality of citizen science data revealed comparable rates of sample integrity, data completeness and mislabeling compared to samples and data collected by trained scientists. Citizen science outreach provided a more informed and engaged online member population, who continued to take actions to advance seafood traceability policies with their decision makers. Citizen science outreach was an integral part of a successful campaign that included science, communication strategies to garner mass media attention and advocacy to promote seafood traceability which resulted in the first seafood traceability regulation in the U.S.
Ocean acidification and warming may threaten future seafood production, safety and quality by negatively impacting the fitness of marine species. Identifying changes in nutritional quality, as well as species most at risk, is crucial if societies are to secure food production. Here, changes in the biochemical composition and nutritional properties of the commercially valuable oysters, Magallana gigas and Ostrea edulis, were evaluated following a 12-week exposure to six ocean acidification and warming scenarios that were designed to reflect the temperature (+3 °C above ambient) and atmospheric pCO2 conditions (increase of 350–600 ppm) predicted for the mid-to end-of-century. Results suggest that O. edulis, and especially M. gigas, are likely to become less nutritious (i.e. containing lower levels of protein, lipid, and carbohydrate), and have reduced caloric content under ocean acidification and warming. Important changes to essential mineral composition under ocean acidification and warming were evident in both species; enhanced accumulation of copper in M. gigasmay be of concern regarding consumption safety. In light of these findings, the aquaculture industry may wish to consider a shift in focus toward species that are most robust to climate change and less prone to deterioration in quality, in order to secure future food provision and socio-economic benefits of aquaculture.
Food authenticity has received an increasing focus due to high profile cases of substitution/mislabeling, with many investigations identifying sales of endangered or prohibited species. At the same time, the European Union (EU) has introduced one of the most progressive sets of legislation in order to promote traceability and protect consumers. This study aims to identify shark species that are sold under the commercial term “Galeos” in Greece (which officially designates Mustelus mustelus, M. punctulatus and M. asterias), using DNA barcoding. A total of 87 samples were collected from fishmongers and markets across four cities. A combination of two mitochondrial genes, the cytochrome c oxidase subunit I (COI) and the 16S ribosomal RNA (16S), were used to analyze samples, and species were identified by reference to genetic databases. The results revealed significant differences in patterns of species utilization between cities and retailers. Across the study an extremely high level of mislabeling was identified (56%). This probably relates to some degree of unintentional misidentification and confusion surrounding the designation in Greece, but highlights how consumers are unprotected from incorrect/misleading labels. Over half of products originated from species that are locally listed as threatened by the ICUN red list, and of the mislabeled products, 23% originated from species with prohibitions on landings or CITES listings. This includes large growing sharks with little resemblance to Mustelus spp. and likely demonstrates deliberate substitution. It shows how mislabeled products are providing a route for prohibited/protected sharks to enter the supply chain and be sold to consumers.