Shellfish Harvesting Research Articles

Nitrogen removal potential of shellfish aquaculture harvests in eastern Canada: A comparison of culture methods

Bivalve farming can contribute to nutrient removal in coastal and estuarine systems, as bivalves directly incorporate nutrients into their tissues and shells. We conducted a meta-analysis to compare the nitrogen removal potential (NRP; i.e., percentage of nitrogen in tissues and shells) of mussels, Mytilus edulis, and oysters, Crassostrea virginica. We then used species-specific NRPs to determine and compare the total and per-hectare NRPs for four shellfish aquaculture methods used in two Atlantic Canadian provinces – New Brunswick (NB) and Prince Edward Island (PEI) – based on current harvest biomasses. Finally, we determined the contribution of current shellfish farming to nitrogen load mitigation for a subset of bays in NB and PEI. Results revealed that on a per-weight basis, NRP was similar for the tissues of mussels and oysters, while mussel shells had a significantly higher percentage of nitrogen than oyster shells. Collectively, shellfish harvesting has the capacity to remove a mean annual total of 99088 kg and 204571 kg of nitrogen from NB and PEI, respectively. Given current harvesting practices for four culture methods employed in the region, suspended mussel culture provides the greatest NRP per hectare of farm area, followed in sequence by suspended mussel and oyster mixed culture, suspended oyster culture, and bottom oyster culture. Preliminary analysis suggested that harvests in the region typically remove <10% of the total nitrogen load on the bay scale, with the exception of bays where nitrogen loads are low and farming intensity is high (where shellfish harvesting can remove higher percentages of nitrogen loads). Ultimately, harvests from shellfish farming in NB and PEI have the capacity to remove substantial amounts of nitrogen from local bays. Future studies assessing the influence of shellfish farming on full nutrient budgets across bays with varying physicochemical conditions will enhance our understanding the role of shellfish farms in nearshore nutrient dynamics, both regionally and globally.

Modeling shellfish harvest policies for food safety: Wild oyster harvest restrictions to prevent foodborne Vibrio vulnificus

Vibrio vulnificus has been identified as one of the main causative agents of foodborne disease associated with shellfish consumption. Infections of V. vulnificus increase during the summer months due to higher densities of the bacteria in warmer water and inappropriate handling of shellfish. In Florida, the daily harvest period is regulated to control the length of time between shellfish harvest and processing, and this harvest period has been recently reduced during the summer months to decrease the risk of foodborne disease. Adoption of this public health policy can affect the profitability and economic sustainability of wild oyster harvesters, especially in resource-dependent coastal communities. This study develops a dynamic and stochastic bioeconomic model to assess the impact of this policy on fishers’ harvest and revenues, and weighs that impact against the policy’s potential public health benefits. Our results show that fishers will experience reduced harvests early in the season due to the shorter harvest hours, but this initial loss is partially recouped later in the season as harvests remain high for longer than they would have if the policy were not in place. This study highlights the relationship between food safety interventions and management of fishery resources, and provides a comprehensive framework for evaluating the costs and benefits associated with such interventions.

Brevetoxin-Producing Spherical Cells Present in Karenia brevis Bloom: Evidence of Morphological Plasticity?

Spherical cells were detected in low salinity waters during a bloom of Karenia brevis in Alabama coastal waters. These balls resembled K. brevis in size and organelle appearance, contained similar concentration of brevetoxin, and occurred during ongoing K. brevis bloom. Based on the environmental conditions in which these cells were observed, we speculate that a rapid drop in salinity triggered the sphere formation in K. brevis. Brevetoxin concentrations were comparable between surface water samples containing typical and atypical cells ranging from 1 to 10 ng/mL brevetoxin-3 equivalents. Accurate identification and quantification of cell abundance in the water column is essential for routine monitoring of coastal waters, so misidentification of these spherical cells may result in significant underestimation of cell densities, and consequently, brevetoxin level. These potential discrepancies may negatively impact the quality of regulatory decisions and their impact on shellfish harvest area closures. We demonstrate that traditional monitoring based on microscopy alone is not sufficient for brevetoxin detection, and supporting toxin data is necessary to evaluate potential risk.

Mesoscale Dynamics and Niche Segregation of Two Dinophysis Species in Galician-Portuguese Coastal Waters.

Blooms of Dinophysis acuminata occur every year in Galicia (northwest Spain), between spring and autumn. These blooms contaminate shellfish with lipophilic toxins and cause lengthy harvesting bans. They are often followed by short-lived blooms of Dinophysis acuta, associated with northward longshore transport, at the end of the upwelling season. During the summers of 1989 and 1990, dense blooms of D. acuta developed in situ, initially co-occurring with D. acuminata and later with the paralytic shellfish toxin-producer Gymnodinium catenatum. Unexplored data from three cruises carried out before, during, and following autumn blooms (13–14, 27–28 September and 11–12 October) in 1990 showed D. acuta distribution in shelf waters within the 50 m and 130 m isobaths, delimited by the upwelling front. A joint review of monitoring data from Galicia and Portugal provided a mesoscale view of anomalies in SST and other hydroclimatic factors associated with a northward displacement of the center of gravity of D. acuta populations. At the microscale, re-examination of the vertical segregation of cell maxima in the light of current knowledge, improved our understanding of niche differentiation between the two species of Dinophysis. Results here improve local transport models and forecast of Dinophysis events, the main cause of shellfish harvesting bans in the most important mussel production area in Europe.

Seasonal scheduling of shellfish collection in the Middle and Later Stone Ages of southern Africa

This study assesses the seasonal scheduling of shellfish harvesting among hunter-gatherer populations along the southernmost coast of South Africa, based on a large number of serial oxygen isotope analyses of marine mollusk shells from four archaeological sites. The south coast of South Africa boasts an exceptional record of coastal hunter-gatherer occupation spanning the Holocene, the last glacial cycle and beyond. The significance of coastal adaptations, in this region in particular, for later modern human evolution has been prominently debated. Shellfishing behaviors are an important focus for investigation given the dietary and scheduling implications and the abundant archaeological shell remains in numerous sites. Key to better understanding coastal foraging is whether it was limited to one particular season, or year-round. Yet, this has proven very difficult to establish by conventional archaeological methods. This study reconstructs seasonal harvesting patterns by calculating water temperatures from the final growth increment of shells. Results from two Later Stone Age sites, Nelson Bay Cave (together with the nearby Hoffman's Robberg Cave) and Byneskranskop 1, show a pronounced cool season signal, which is unexpected given previous ethnographic documentation of summer as the optimal season for shellfishing activities and inferences about hunter-gatherer scheduling and mobility in the late Holocene. Results from two Middle Stone Age sites, Klasies River and Pinnacle Point 5–6, show distinct seasonal patterns that likely reflect the seasonal availability of resources in the two locations. The Pinnacle Point 5–6 assemblage, which spans the MIS5-4 transition, records a marked shift in shellfishing seasonality at c. 71 ka that aligns with other indications of archaeological and environmental change at this time. We conclude that the scheduling and intensity of shellfishing in this region is affected by a suite of factors, including environmental and cultural drivers, rather than a single variable, such as population growth.

Occurrence of Marine Biotoxins and Shellfish Poisoning Events and Their Causative Organisms in Argentine Marine Waters

In the Argentine Sea, marine phycotoxins of microalgal origin associated with five shellfish poisoning syndromes have been reported. The most problematic in terms of toxicity and geographic distribution is paralytic shellfish poisoning (PSP), followed by diarrhetic shellfish poisoning (DSP). In contrast, amnesic shellfish poisoning (ASP), spiroimine shellfish poisoning (SSP), and azaspiracid shellfish poisoning (AZP) have not been reported to cause human illness or closures of shellfish harvest sites in Argentina to date but pose a potential risk, as associated toxins and producing organisms are present in Southwest Atlantic waters and were detected at subregulatory levels in mollusks. Alexandrium catenella and Gymnodinium catenatum have been identified as producers of the PSP toxins C1/2, gonyautoxins (GTX1-4), saxitoxin (STX), and neosaxitoxin (NEO) in the Argentine Sea. Nine potentially toxigenic species of the diatom genus Pseudo-nitzschia have been reported for Argentinean coastal waters: P. australis, P. brasiliana, P. delicatissima, P. fraudulenta, P. multiseries, P. pseudodelicatissima, P. pungens, P. seriata, and P. turgidula, all of which are known to produce the neurotoxin domoic acid that causes ASP. Two genera have been identified as producers of DSP toxins in Argentina: the benthic dinoflagellate Prorocentrum lima and several species of the pelagic dinoflagellate genus Dinophysis: D. acuminata, D. caudata, D. fortii, D. norvegica, and D. tripos. The occurrence of these species in Argentine waters is associated with okadaic acid (OA), dinophysistoxin-1 (DTX-1), pectenotoxin-2 (PTX-2), and pectenotoxin-2 seco acid (PTX-2sa). Historically, yessotoxins (YTXs) were also included in DSP syndrome and all three known YTX-producers have been confirmed in Argentinean waters: Gonyaulax spinifera, Lingulodinium polyedra, and Protoceratium reticulatum, but of these only P. reticulatum could be associated with YTX production to date. Several species of the family Amphidomataceae, which cause AZP, have been reported for Argentina: Amphidoma languida, Azadinium dexteroporum, Az. luciferelloides, Az. poporum, and Az. spinosum. In Argentinean coastal waters, out of these species only Az. poporum has been identified as toxigenic to date, as it produces azaspiracid-2 (AZA-2) and its phosphorylated form. Currently in Argentina, seafood is monitored for the risk of ASP, AZP, DSP, and PSP.

Monitoring metal pollution on coastal lagoons using Cerastoderma edule-a report from a moderately impacted system in Western Portugal (Óbidos Lagoon).

The main goal of this monitoring program was to evaluate the contamination in the intertidal environment of Óbidos Lagoon by the metals Cd, Pb, and Ni on water, sediments, and on biological samples, using the bivalve Cerastoderma edule (common name: cockle) as a biomonitor. Since C. edule is an edible mollusc, the risk of their consumption by humans from this lagoon was also evaluated. The study was performed in a restricted area of the lagoon-the ML station-where human activities, such as shellfish harvesting, intersect with the natural processes occurring in this system. The results obtained revealed that the water samples were polluted with Cd and Pb with concentrations (0.00025mgl-1 and 0.0072mgl-1) above the maximum legislated on the Directive 2008/105/EC, while for Ni, this occurred only on one of the seasons sampled (summer 2010: 0.029mgl-1). The sediments were not contaminated with Cd and Ni, and the contamination detected for the metal Pb, allowed the classification of this station as an unpolluted site ([Pbmin] = 7.477mg.kg-1 and [Pbmax] = 19.875mg.kg-1). On biological samples, comparing the results of metal contaminations with the values of the maximum levels fixed by European Commission Regulation (EC) No 1881/2006 and USFDA, all the results were below the legal value. Therefore, during the period of study, the consumption of this bivalve by humans was safe. Also, BAF and CF calculations suggest that C. edule can be used as a biomonitor to determine the source of the contaminations. This study supported the use of C. edule as a biomonitor to assess the contamination by the metals Pb and Ni at the Óbidos Lagoon and allowed to predict the potential transfer of metals to higher trophic levels with potential impacts on the natural and human communities.

Hydrogeochemistry of the Subaé River Impacted by Lead Smelting Activities, Bahia State, Brazil: Geochemical Characterization and Fluxes of Metals

The Subae river watershed is considered one of the most critical Pb-impacted environments in Brazil and around the world, due to pollutant dispersion during 33 years of lead ore purification in Santo Amaro da Purification. Severe damages have been reported in biota and population, which depends on the Subae river watershed quality for agriculture, fishing, and shellfish harvesting. This study aims to understand the geochemical characteristics and dynamics of the river close to the former Pb smelter. The river was sampled at eight sites upstream and eight sites downstream the smelter, near the estuary in the Todos os Santos Bay, six times during a year. Immediate analyses were performed by multiprobe. Major ions were measured by chromatography, dissolved metals by ICP-OES in the filtrated samples (0.45 μm), and particulate metals > 0.45 μm by EDX spectrometry. The ions Na+ and HCO3− are dominated in the river. Most of the samples (47.6%) were classified as sodic, due to oceanic saline intrusion during tide. Despite the high pollution caused by the smelter from 1960 to 1993, still observed in the surrounding soils, dissolved and particulate metals in the river remained low in all sites during the entire year. Only Cu presented some concentration above the threshold of the Brazilian regulations. The discharge of metals by the river into the Todos os Santos Bay appears to be low for Pb and Zn (2.2 and 14.3 kg km−1 year−1, respectively), but higher for Cu comparatively to other worldwide bays.

Influence of sudden salinity variation on the physiology and domoic acid production by two strains of Pseudo-nitzschia australis.

Several coastal countries including France have experienced serious and increasing problems related to Pseudo-nitzschia toxic blooms. These toxic blooms occur in estuarine and coastal waters potentially subject to fluctuations in salinity. In this study, we document for the first time the viability, growth, photosynthetic efficiency, and toxin production of two strains of Pseudo-nitzschia australis grown under conditions with sudden salinity changes. Following salinity variation, the two strains survived over a restricted salinity range of 30-35, with favorable physiological responses, as the growth, effective quantum yield and toxin content were high compared to the other conditions. In addition, high cellular quotas of domoic acid (DA) were observed at a salinity of 40 for the strain IFR-PAU-16.1 in comparison with the other strain IFR-PAU-16.2 where the cell DA content was directly released into the medium. On the other hand, the osmotic stress imposed at lower salinities, 20 and 10, resulted in cell lysis and a sudden DA leakage in the medium. Intra-specific variability was observed in growth and toxin production, with the strain IFR-PAU-16.1 apparently able to withstand higher salinities than the strain IFR-PAU-16.2. On the whole, DA does not appear to act as an osmolyte in response to sudden salinity changes. Since most of the shellfish harvesting areas of bivalve molluscs in France are located in areas where the salinity generally varies between 30 and 35, Pseudo-nitzschiaaustralis blooms might potentially impact public health and commercial shellfish resources in these places.

Statistical models of fecal coliform levels in Pacific Northwest estuaries for improved shellfish harvest area closure decision making

There is a substantial need for tools that effectively predict spatial and temporal fecal pollution patterns in estuarine waters. In this study, statistical models of exceedances of shellfish fecal coliform (FC) water quality criteria were developed using a 10-year dataset of FC levels and environmental data. Performance (sensitivity, specificity, and predictive capacity) of five different types of models was tested (MLR regression, Tobit (censored) regression, Firth's binary logistic regression (BLR), classification trees, and mixed-effects regression) for each of three conditionally managed shellfish-harvesting areas in Tillamook Bay, Oregon (USA). The most influential variables were related to precipitation and river stage height in the wet season and wind and tidal-stage in the dry season. Classification tree and Firth's BLR approaches better explained exceedances of shellfish water quality standards than the current closure thresholds. Findings demonstrate the utility of statistical modeling approaches for improved management of shellfish harvesting waters.

Nutritional Value and Food Safety of Bivalve Molluscan Shellfish

The Nutrient Database for Standard Reference published by the U.S.D.A. describes molluscan shellfish as an excellent source of vitamin B12, omega-3 fatty acids, choline, iron, selenium, and zinc. Edible molluscs consist primarily of mussels, clams, scallops, and oysters and are naturally low in carbohydrate, as well as total and saturated fat. With regard to omega-3 fatty acids, iron, selenium, and zinc, the nutrient value of some shellfish is superior to land-based protein sources, such as beef, chicken, and pork. Unfortunately, adverse human health considerations need to be noted because of naturally occurring pathogens, particularly Vibrio species, and algal toxins (brevetoxin, saxitoxin, and domoic acid) that may be present in these shellfish, as well as fecal-associated viruses (hepatitis A and norovirus) and bacteria (Salmonella) as a consequence of contamination of shellfish harvest sites. Other environmental contaminants (mercury, methylmercury, and polychlorinated biphenyls) may bioaccumulate in molluscan shellfish tissues as part of their filter feeding behavior and have potential health implications. Cooking molluscan shellfish greatly reduces the risk of foodborne infections and increases the nutrient value because of water loss; however, some vitamins are destroyed by cooking and natural toxins and environmental contaminants are not always eliminated by normal cooking temperatures. Coastal monitoring of water quality and postharvest processing of some products should help mitigate risks associated with shellfish consumption and promote a safer, nutrient-rich product.

Economic and sociocultural impacts of fisheries closures in two fishing-dependent communities following the massive 2015 U.S. West Coast harmful algal bloom

In the spring of 2015, a massive harmful algal bloom (HAB) of the toxin-producing diatom Pseudo-nitzschia occurred on the U.S. West Coast, resulting in the largest recorded outbreak of the toxin domoic acid and causing fisheries closures. Closures extended into 2016 and generated an economic shock for coastal fishing communities. This study examines the economic and sociocultural impacts of the Dungeness crab and razor clam fisheries closures on two fishing-dependent communities. Semi-structured interviews were conducted with 36 community members from two communities impacted by the event – Crescent City, California and Long Beach, Washington. Interviewees included those involved in the fishing, hospitality, and retail industries, local government officials, recreational harvesters, and others. Interviews probed aspects of resilience in economic, social, institutional, and physical domains, based on the contention that community resilience will influence the communities’ ability to withstand HAB events. Dimensions of vulnerability were also explored, encompassing sensitivity of the communities to HAB events and their adaptive capacity. Common themes that emerged from the interview responses indicate that economic hardships extended beyond fishing-related operations and permeated through other sectors, particularly the hospitality industry. Significant barriers to accessing financial and employment assistance during extended fisheries closures were identified, particularly for fishers. Long-held traditions surrounding crab and shellfish harvest and consumption were disrupted, threatening the cultural identities of the affected communities. Community members expressed a desire for clearer, more thorough, and more rapid dissemination of information regarding the management of fisheries closures and the health risks associated with HAB toxins. The likelihood of intensifying HABs under climate change heightens the need for actions to increase the resilience of fishing communities to the economic and sociocultural impacts caused by HAB-related fisheries closures.

Spatial and Temporal Characteristics of Vibrio Parahaemolyticus in the Chesapeake Bay

Vibrio parahaemolyticus naturally occurs in estuaries and is a leading cause of seafood-borne illness. It is therefore necessary to develop ecological prediction tools for shellfish harvesting waters. Such predictions need adequate spatial and temporal resolution as bacterium abundance fluctuates frequently.Previous work identified environmental determinants of V. parahaemolyticus in the tidal waters of the Chesapeake Bay using a large data set (n&amp;#61; 1,385) collected from 148 monitoring stations between 2007-2010. Regression models were developed using water samples analyzed by qPCR along with spatially- and temporally-indexed water quality data. Previously identified relationships with temperature and turbidity were confirmed, while more complex relationships were identified for nitrogen and phosphorus. Non-linear associations with salinity were determined to be a function of both low temperature and turbidity.Recent work attempted to develop V. parahaemolyticus prediction models using time-indexed and 1- and 2-month lagged water quality measures. Tobit regression models were evaluated using cross-validation methods to quantify prediction bias and uncertainty. The results were promising, indicating that water quality data can provide adequate prediction for bacterium presence and abundance, and that lagged measures provide complimentary or superior predictive power when compared to time-indexed measures.Current work is expanding variable selection for prediction models and increase the spatial-temporal extent of such predictions by using geostatistical interpolation techniques. These modeling efforts will culminate in a prediction tool that will provide real-time forecasts of V. parahaemolyticus. These prediction models will better inform shellfish harvesters and regulators on when and where preventative food safety post-harvesting practices are necessary.

Variations in morphology, growth, and toxicity among strains of the Prorocentrum lima species complex isolated from Cuba and Brazil

Benthic dinoflagellates belonging to the genus Prorocentrum are known to produce diarrhetic toxins such as okadaic acid (OA) and its analogues, dinophysistoxins (DTXs), as well as prorocentrolides and other unidentified fast-acting toxins. The present study is a comparative analysis focused on the morphology, genetic, growth, toxin production, and toxicity by strains belonging to the Prorocentrum lima species complex, isolated from different regions along the western Atlantic coast. While cell dimensions (38–45 × 24–30 μm) and shape (ovoid) were similar between strains from Cuba and Recife (Northeast Brazil), cells of the strain from the estuarine complex of Paranagua Bay (South Brazil) were shorter (36–41 × 25–28 μm) and oblong to ovate-oblong (elliptical) in shape. This latter strain exhibited similar LSU rDNA and identical ITS1-5.8S rDNA-ITS2 sequences to those of P. cf. lima “morphotype 5,” which is closely related to Prorocentrum caipirignum by LSU, but separated from it by ITS. This southern Brazilian strain attained the highest growth rate (0.34 ± 0.01 div day−1) and cell densities (11.2 × 105 cell mL−1) in batch culture. Intracellular OA concentrations were higher for the other two strains during the late exponential and stationary phase, but similar for all strains (9.50–10.06 pg cell−1) at the early exponential growth phase; consistently lower levels of DTX-1 were produced by two strains, except the one from Recife. Finally, live cells of the strains from Cuba and Recife were more toxic to A. salina metanauplii, whereas the southern Brazilian strain exhibited higher culture medium toxicity. The contrasts in growth and toxicity potential revealed for these morphologically and genetically distinct Prorocentrum strains might be relevant for the local management of diarrhetic poisoning outbreaks in shellfish harvesting and aquaculture sites, including in estuarine areas.

Using a Numerical Model to Track the Discharge of a Wastewater Treatment Plant in a Tidal Estuary

Along the coast of Maine, USA, there are numerous wastewater treatment plants that discharge their treated effluents into a river estuary which is shared by commercial fishing and shellfish harvesting. Occasionally, there can be failures or bypasses of treatment plants that lead to untreated or partially treated sewage flowing into shellfish harvesting waters. To prevent any toxic contamination of harvested shellfish, a prohibitive zone is established around the treatment plant where shellfish harvesting is prohibited. The U.S. Food and Drug Administration has conducted numerous dye studies on both coasts of the USA to determine these prohibitive zones, based on the guidelines of the National Shellfish Sanitation Program. In May 2010, the FDA conducted such a dye study at the Yarmouth, Maine wastewater treatment plant. The results are compared with a numerical coastal model that provides the velocity field for the currents around the treatment plant. This model includes a diffusion equation to simulate dye dispersion from a point source which is used to determine the prohibitive zone. The numerical model shows good correlation with the FDA dye study report and establishes a prohibitive zone for commercial harvesting in keeping with that of the FDA study. The benefits of the numerical model include sampling at thousands of locations simultaneously, seasonal changes in river volumes, and changes in plant discharge volumes.

Shellfish Exploitation in the Western Canary Islands Over the Last Two Millennia

ABSTRACTThe residents of the Canary Archipelago consumed limpets since the arrival of humans ∼2500 yrs. ago, and these harvested gastropods were deposited in large coastal shell middens. This work preliminarily explores shell margin oxygen isotope composition (δ18O) and body size of the black limpet (Patella candei d’Orbigny, 1840) from archaeological sites in the Canary Islands to assess possible seasonal variability and intensity of shellfish collection throughout the late Holocene. The shell margin δ18O values of 100 shells (radiocarbon dated between ∼500 and ∼1800 cal. yr BP) were analysed to estimate sea surface temperature (SST) at time of death. Paleotemperature estimates suggest shellfish harvesting was not year-round, and was avoided in the cooler months (when SST < 20°C). This pattern differs from most higher latitude Mesolithic and Neolithic human groups, which gathered shellfish year-round, targeting winter more heavily. Preliminary body-size measurements suggest shell sizes have experienced a decline from aboriginal times to the present, which possibly resulted from increasing anthropogenic pressures. During aboriginal inhabitation, maximum adult shell size remained stable, suggesting that present-day harvesting practices are more intense than harvesting from aboriginal human groups. This intensive collection has likely diminished the average adult size of limpet populations in the islands by ∼27%.

Aptamer-Based Biosensors to Detect Aquatic Phycotoxins and Cyanotoxins.

Aptasensors have a great potential for environmental monitoring, particularly for real-time on-site detection of aquatic toxins produced by marine and freshwater microorganisms (cyanobacteria, dinoflagellates, and diatoms), with several advantages over other biosensors that are worth considering. Freshwater monitoring is of vital importance for public health, in numerous human activities, and animal welfare, since these toxins may cause fatal intoxications. Similarly, in marine waters, very effective monitoring programs have been put in place in many countries to detect when toxins exceed established regulatory levels and accordingly enforce shellfish harvesting closures. Recent advances in the fields of aptamer selection, nanomaterials and communication technologies, offer a vast array of possibilities to develop new imaginative strategies to create improved, ultrasensitive, reliable and real-time devices, featuring unique characteristics to produce and amplify the signal. So far, not many strategies have been used to detect aquatic toxins, mostly limited to the optic and electrochemical sensors, the majority applied to detect microcystin-LR using a target-induced switching mode. The limits of detection of these aptasensors have been decreasing from the nM to the fM order of magnitude in the past 20 years. Aspects related to sensor components, performance, aptamers sequences, matrices analyzed and future perspectives, are considered and discussed.

Salt Marsh Restoration and the Shellfishing Industry: Co-evaluation of Success Components

This study uses an ecosystem services framework to document the current relationship between salt marsh restoration and the shellfishing industry in five towns on Cape Cod, Massachusetts, USA. Salt marshes in their natural form provide many ecologic, economic, and aesthetic benefits to coastal communities. Human alterations to salt marshes (including ditching, diking, and filling), however, restrict water flow, substantially reducing the ecosystem services available to these communities. Salt marsh restoration projects have been implemented along coastal landscapes in an attempt to reclaim their original ecosystem services. The ecologic and social components of restoration, like its connection to the shellfish industry, are well understood, but the inherent linkages between the components are not. Through the co-evaluation of these components, social and ecologic linkages are identified and assessed. This study determined the robust social link between salt marsh restoration and the shellfishing industry. Despite the lack of a clear link between restoration and enhanced ecosystem services that augment shellfish harvest, restoration projects are valued for far more than their direct provisioning ecosystem services, with many shellfishermen emphasizing the cultural value of the salt marsh above all else. The sense of community and culture that rallies around both salt marsh restoration and shellfishing demonstrates that valuation of ecosystem services is robust and imperative to the future of both salt marshes and the shellfishing industry on the outer Cape.

How much in the clan are you? The community as an explanatory factor of the acceptance of poaching in small-scale fisheries

This work is an in-depth look at the acceptance of poaching in Galicia, exploring the role of the community in tolerating acts of non-compliance with shellfishing regulations in Noia, (Galicia, Northwest of Spain). Tolerated non-compliance attitudes were identified and as a result it was possible to define the motivations behind poaching and which individuals are potentially acceptable in the target community. It was concluded that formal access and withdrawal property rights to shellfishing resources are only granted by the formal users of the resources under certain circumstances, but, fundamentally, only to individuals who are recognised as belonging to the community. To this regard, the concept of community is what sustains the possibilities of co-managing the resources and the acceptance of certain shellfish poaching acts within the community in question. Once the possibility of acceptance was established, the perceptions of the shellfish harvesters were used to measure tolerance towards poaching by asking the following question: Up to what point can poaching be tolerable? The information used in this work was collected in 95 surveys carried out between February and April 2017.

Past-present discontinuity in ecological change and marine governance: An integrated narrative approach to artisanal fishing

Today artisanal fishers working in Natura 2000 coastal protected sites face two major types of change: in marine resources, and the governance of their professions. Such transformations affect fishers’ livelihoods, identities and traditions, yet little is known about how these professionals elaborate on these changes – i.e., as continuities or discontinuities - in the narratives they produce as a group. Interviews and focus-groups with artisanal fishers and shellfish harvesters (n = 36) from the Portuguese Southwest coast were subjected to a two-step analysis. First, a textual analysis with Iramuteq helped select the themes directly related to marine resources and governance. Second, three main narratives - on algae, barnacles and fish - were reconstructed. These were then explored regarding: (1) narrative formats (stability, regressive, progressive, mixed); (2) whether/how these formats elaborated changes as continuities or discontinuities; (3) the roles attributed to Self and Others, and whether and how these legitimized the laws, opening avenues for change; and (4) whether narratives were unified or fragmented. This study illustrates how transformations are presented through various combinations of narrative formats, sometimes mobilized to resist and other times to legitimate legal institutional change. It shows how institutional change can be integrated into local narratives as a positive contribution through a process that implies re-constructing the collective identity and local traditions. Through a narrative approach, this paper offers an integrated examination of fishers’ concerns towards their professions and the laws regulating them, and provides useful insight into how and when marine governance is more/less likely to be legitimized.