Shellfish Farming Research Articles

Mediterranean Mussels (Mytilus galloprovincialis) Under Salinity Stress: Effects on Antioxidant Capacity and Gill Structure.

Bivalve mollusks frequently experience salinity fluctuations that may drive oxidative stress (OS) in the organism. Here we investigated OS markers and histopathological changes in gills and hemolymph of Mediterranean mussels Mytilus galloprovincialis Lamarck, 1819 exposed to a wide range of salinities (6, 10, 14, 24, and 30 ppt). Mussels were captured at the shellfish farm with the salinity 18 ppt and then exposed to hypo- and hypersaline conditions in the laboratory. Indicators of redox balance in hemocytes (intracellular reactive oxygen species (ROS) levels, DNA damage) and gills (thiobarbituric acid reactive substances (TBARS), protein carbonyls (PC), activity of catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx) were measured. The effect of salinity stress on microstructure of gills has been evaluated as well. The results revealed induction of OS in tissues and cells of mussels for both experimental increase and decrease salinity modelings. Hemocytes showed higher sensitivity to osmotic stress compared to gills. In gills TBARS were stable in all experimental groups and PC increased only at salinity 6 ppt. The activity of SOD, CAT and GPx in gills decreased only in mussels acclimated to salinity 24 ppt and further salinisation up to 30 ppt was associated with the recovery of the activity of all enzymes. Major histopathological changes in gills upon salinity fluctuations included inflammatory reactions, circulatory alterations, regressive and progressive changes. Our findings clearly indicate that salinity fluctuations promote OS at cellular and tissue level and also affect microstructure of gills in mussels. The results provide new insights into the mechanisms of osmotic stress in bivalves.

Isolation of Shewanella algae from blue crabs (Callinectes sapidus) in Northwestern Adriatic Sea

Abstract Blue crab (Callinectes sapidus) is one of the last reported invasive species that have colonized the Italian coasts, in particular the lagoons of the northern Adriatic Sea. Their massive presence is compromising shellfish farming, causing a serious economic crisis among the valley populations. To limit the economic damage, blue crabs have been introduced as human food in the Italian markets. This study aimed to evaluate the microbiological contamination of blue crab as potential risk to human health. From July 2023 to April 2024, 72 blue crabs were collected in coastal lagoons and 5-6 nm from the coast of the Emilia Romagna Region. Microbiological analysis revealed Shewanella algae as one of the most commonly identified microorganisms (18/72, 25%). Shewanella was isolated on Chromagar Vibrio™ and TCBS after an enrichment step in Alkaline Saline Peptone Water. Colony morphology, Gram stain, and biochemical tests (oxidase, catalase) sustained Shewanella identification, later confirmed by MALDI-TOF MS (MALDI Biotyper® Sirius, Bruker Daltonics). S. algae is a Gram-negative, rod-shaped, aerobic microorganism widely distributed in seawater, freshwater, and soil. In humans, it is considered an opportunistic pathogen, especially in people with impaired immune systems. Shewanellosis has been strongly associated with seawater exposure and typically arises in hot months. Clinical manifestations include skin and soft tissue infections, otitis media, keratitis, biliary tract infections, vertebral discitis, and bloodstream infections. Notably, in the last years, S. algae infections have increased globally, even in healthy young people. The present study suggests blue crabs as a potential source of S. algae throughout the year. The increasing identification of S. algae in marine waters worldwide, as well as in marine-derived foods like blue crabs, underscores the growing importance of S. algae as an emerging pathogen and its impact on public health. Key messages • Shewanella algae is an opportunistic pathogen, increasingly isolated in marine water and seafood. • Blue crab is an invasive species that has recently conolonised the Italian coasts.

Numerical modeling of an offshore shellfish farm exposed to extreme wave conditions

Shellfish cultivation is a sustainable method of providing human food and can help remove large amounts of CO2 from the atmosphere. Over the last two decades, longline-based structures have dominated farming systems. So far, the innovative technologies for open-ocean shellfish farming remain stagnant and need to be developed. As such, this paper preliminarily studies the operation and survivability abilities of an innovative shellfish farm under extreme wave conditions. To that end, an efficient numerical scheme with a robust implicit finite element method is established. First, the numerical modeling of a single module of the shellfish farm is conducted and the numerical results are verified against physical model tests. Then, the numerical modeling is implemented in a full-scale shellfish farm containing nine floating rafts with suspended lantern nets in a 3×3 configuration exposed to extreme wave conditions. Different angles of wave attack and shellfish rafts with and without lantern nets are fully considered, allowing an assessment of the operation and survivability abilities of the shellfish farm under extreme wave conditions in various situations. The results highlight that the angle of wave attack significantly affected the energy absorption of the mooring system. Moreover, non-linear instability such as subharmonics, which existed in the motion dynamics, can be manipulated to avoid resonant motions. This study provides insights into the evaluation of the safety design of a shellfish farm at both operational and survivability levels. The numerical method can also model other advanced offshore marine structures with multi-modules, such as floating bridges, airports, and even floating energy islands.

Morphological and molecular characterization of two potentially toxigenic species of the genus Pseudo-nitzschia (Bacillariophyceae) in Luzon Island, Philippines

Harmful algal blooms are a major concern for the environment and industries like fisheries, healthcare, and tourism in coastal countries such as the Philippines. Blooms of diatoms (Bacillariophyceae) seldom cause harm, but half of the species in the cosmopolitan genus Pseudo-nitzschia produce the neurotoxin domoic acid. Only two published Pseudo-nitzschia surveys in the Philippines carried out morphology-based species identification. Molecular taxonomy has revealed a high level of cryptic diversity corresponding to minute morphological differences. This study sought to explore the diversity of and characterize the genus Pseudo-nitzschia in mariculture zones around Luzon Island using morphological and molecular information. Ten culture strains of Pseudo-nitzschia isolated from shellfish farms were used for morphological and molecular species identification. The secondary structure of the internal transcribed spacer 2 region revealed five strains from Pagbilao Bay to be most similar to P. brasiliana, the first record of this species in Luzon. Meanwhile, four Bacoor isolates and one from Pagbilao clustered within a monophyletic clade representing P. pungens, previously found in Manila Bay. Three single nucleotide polymorphisms and one hemi-compensatory base change were found among the P. pungens strains. Morphological characters, specifically cell shape, apex shape, and poroid density confirmed both species identities. Based on band striae, all P. pungens strains were of the nominal variety, P. pungens var. pungens. This study is among the first culture-based taxonomic studies of diatoms in the Philippines, in this case confirming the presence of harmful microalgae in the coastal ecosystems of the country.

Ultrasensitive on-site colorimetric detection of Campylobacter in oyster with a portable biosensing platform based on hydroxamate/Fe3+–violurate chromogenic reaction and smartphone

The contamination of Campylobacter in shellfish poses a health risk for its pathogenicity associated with campylobacteriosis. However, an efficient method to detect this risk is unavailable. Herein, we introduce a portable colorimetric biosensing platform that comprises three modules: an enrichment module 1, a binding and transduction module 2, and a smartphone-based module 3. Module 1 is an aptamer-modified 96-well plate for the specific capture of Campylobacter in a simple and high-throughput manner. Module 2 features a bifunctional biopolymer of L-glutamic acid γ-hydroxamate–alginate–Fe3+ coordinating fusarinine C, which can bind the captured Campylobacter cells and transduce them into amplified color signals upon reaction with Fe3+–violurate complexes. Module 1 achieves a capture efficiency of 97.24%, and the subsequent addition of module 2 renders colorimetric indication of Campylobacter ranging from 101 to 106 CFU/mL, achieving an actual limit of detection of 8 CFU/mL validated by Campylobacter single-cells. Moreover, the generated colors can be recognized and converted into cell densities by module 3 with ultrasensitivity. Notably, this biosensor–smartphone platform accomplishe reliable high-throughput colorimetric detection of Campylobacter in real samples with an accuracy of 80%. This work showcases a proof of principle for efficient on-site detection of Campylobacter contamination regarding shellfish farming.

Integrating source tracking tools for marine shellfish tracing: Metataxonomic and isotopic analyses

Shellfish farming is a significant activity in the Northern Adriatic Sea, particularly in Italy, where it plays a crucial role in the European industry of live bivalve mollusks. This study aimed to exploit different analyses, including metataxonomy and isotopic profiling, to address these issues. Isotopic analysis showed differences between habitats, with lower δ15N in sea samples, likely indicating lesser anthropogenic impact compared to lagoon environments. Additionally, seasonal variations in δ15N, δ13C and C/N highlighted differences in primary productivity and organic matter sources across seasons. Metataxonomic analysis revealed significant variability in microbial taxa across harvesting habitats and seasons. While no marked differences were observed in alpha and beta diversity based on habitat, distinct seasonal clustering indicated the influence of environmental factors on microbial community structure. Gammaproteobacteria were prevalent across habitats and seasons, with notable fluctuations in other taxa, such as Alphaproteobacteria, Epsilonproteobacteria, Flavobacteria, and Bacteroidia, particularly in lagoon habitats during winter. Overall, this study highlights the potential of microbial and isotopic characterization for tracing the origin of shellfish products. Metataxonomic analysis identified microbial signatures indicative of habitat and season, with implications for ecological dynamics and consumer safety. Isotopic analysis provided information on habitat characteristics and harvesting seasons, enhancing product traceability.

The past, present and future developments in mariculture in the coastal waters of mainland Tanzania

AbstractMarine coastal resources are crucial to Tanzania's socio‐economic development and are a lifeline for the livelihoods and incomes of coastal communities. This study provides an overview of the coastal development of mariculture in mainland Tanzania and suggests future development strategies. The review article covers extensive reports available through field interviews, government policy documents, library literature searches and field work carried out by the authors. Despite the immense potential of mariculture to improve food security for localcommunities, its development has been uneven. Specifically only seaweed farming has advanced to commercial‐scale production. Other mariculture activities, such as finfish farming (e.g. milkfish, silver pompano), shellfish farming (e.g. prawn, mud crab and half‐pearl) and sea cucumber farming, are underdeveloped and confined to small‐scale operations. Locally consumed finfish, such as milkfish and pompano, have not attracted investors out of fear that the recovery of investment may not be achieved due to the low prices offered in the market. In this context, the sustainable use of coastal resources through mariculture becomes paramount to alleviating poverty and facilitating controlled migration from rural to urban. This comprehensive review explores the historical evolution and current status of mariculture initiatives in the coastal waters of mainland Tanzania, which presents a crucial aspect of the socio‐economic development of the nation. With declining global capture fisheries production and a growing demand for fish protein, Tanzania has strategically embraced mariculture as a viable alternative. The article traced the development of mariculture since the 1970s, highlighting past and current initiatives managed by government agencies, non‐government organizations and the private sector. Notable successes, such as seaweed culture, are highlighted along with the challenges that hinder the growth of marine farming activities. The review integrates insights from a comprehensive survey in coastal Tanzania, focusing on mariculture activities and collecting information on people who have stopped such practices, elucidating reasons for quitting. By consolidating experiences from past and present mariculture initiatives, this review provides valuable guidance for decision‐making towards promoting sustainable mariculture that supports coastal communities while preserving marine biodiversity.

Ancestral and contemporary intertidal mariculture practices support marine biodiversity in the northeast Pacific

The cultivation of seafood now outpaces extraction from wild populations. This novel state in the history of human-marine ecosystem interactions highlights the importance of identifying cultivation practices that balance production and conservation. Here, we test the hypothesis that two shellfish cultivation practices, one that spans decades and the other millennia, bolsters habitat complexity, which increases epifaunal (surface) invertebrate diversity. To do so, we conducted multiple surveys of 24 First Nations clam gardens, shellfish aquaculture farms, and non-walled or unmodified beaches along the west coast of Canada. We show that habitat alterations specific to each cultivation practice restructure epifaunal communities at several ecological and spatial scales. Distinct communities within clam gardens and shellfish farms are a function of habitat complexity at 25–50 and 50–100 cm resolutions and changes in the amount of gravel, bivalve shells, and seaweeds. Our findings highlight how resource cultivation can contribute to achieving sustainable human-ecosystem interactions.

Evaluating coastal lagoon sustainability through the driver-pressure-state-impact-response approach: a study of Khenifiss Lagoon, southern Morocco

Coastal lagoons are valuable ecosystems, providing socioeconomic benefits and supporting human populations and biodiversity. However, these systems face several challenges, making them vulnerable to both natural and human factors. In this study, we apply the Driver-Pressure-State-Impact-Response (DPSIR) Approach to conduct a comprehensive socioeconomic and environmental assessment of the Khenifiss Lagoon to promote sustainable development and support decision-makers. Located on the southern Atlantic coast of Morocco, the lagoon was designated a natural reserve in 1962, a biological reserve in 1983, and a protected wetland under the Ramsar Convention since 1980. This study represents the initial endeavor to conduct a comprehensive global and multidisciplinary environmental assessment of the lagoon by using a wide range of data sources, including relevant publications and reports, satellite images and remote sensing data, field observations, and interviews, all analyzed under the DPSIR framework. Our findings show that both natural and human factors have an impact on the ecosystem. Natural Factors associated with the geomorphological features of the region likely contribute to the silting of the lagoon, possibly intensified by a large shipwreck stuck at its inlet. Meanwhile, human factors encompass population growth (at a rate of 2% per year), tourism, shellfish farming, fishing, shellfish harvesting, and salt extraction. Our results reveal significant changes in the lagoon’s condition in recent years, including a reduction in water body extent, a probable decrease in depth, and an increase in the accumulation of solid waste, plastics, and wastewater in three sectors spanning a total surface area of 464 ha (equivalent to 7% of the lagoon), a substantial expansion of the salt mining area encompassing 368 ha, and a remarkable loss of biodiversity, manifested in declining fish stocks and seabird populations. This study showed that the lagoon is positioned as a potential site for economic growth and serves to alert stakeholders and the local population to the ecosystem’s environmental issues. Based on the findings of this study, we highly recommend regulating human activities within the lagoon, the removal of the wreck at the entrance, proper waste management, community awareness programs, and strict monitoring and enforcement of regulations to protect the environment.

Issues and Needs for the Sustainable Development of Shellfish Farming in Italy

Issues and Needs for the Sustainable Development of Shellfish Farming in Italy

Tunable dye adsorbing materials from crab and shrimp waste shells for water remediation

Crab and shrimp shells are waste byproducts from shellfish farming and processing. In this study, we demonstrated that it is possible to obtain individual shell components either separately or in combinations. These diverse materials were composed of calcium carbonate and organic molecules inter- and intra-mineral, calcium carbonate and organic molecules intra-mineral, organic molecules such as chitin and proteins, only calcium carbonate, and only chitin. These substrates were tested for the adsorption of Methylene Blue and Eosin dyes. The goal is to demonstrate that the organic dye adsorption capacity can be modified by controlling the degree of deconstruction of the starting material. The best adsorption for the positively charged Methylene Blue was achieved on the chitin-calcium carbonate substrates, while the negatively charged Eosin adsorbed best on the chitin substrate. In conclusion, this research demonstrates that it is possible to obtain different materials by deconstructing the shells from crabs and shrimps at various levels reducing the generation of additional wastes. Moreover, these materials exhibit features that are related to the original material and possess new properties that can be also exploited in other fields like material sciences.

Mussel Culture Activities Facilitate the Export and Burial of Particulate Organic Carbon

The recent expansion of shellfish mariculture could significantly impact the ocean carbon cycle and its associated biogeochemical processes. To understand the source and fate of particulate organic carbon (POC), a summer cruise was conducted from September 8 to 10, 2022, at a mussel farm on Gouqi Island and its adjacent areas located in the East China Sea. Parameters included in situ temperature and salinity, contents of dissolved oxygen (DO), suspended particulate matter (SPM), POC, and chlorophyll a (Chl a), as well as the stable carbon isotopic composition (δ13C) of organic matter in particle and sediment samples, which were analyzed to facilitate a comparative assessment of the areas inside and outside the mussel farm. The POM was much fresher (POC/Chl a < 150) inside the farm with little impact from sediment resuspension (lower SPM content, 11.6 ± 6.6 mg/L), while a significant influence of sediment resuspension was found outside the farm (SPM > 20 mg/L, POC/Chl a > 150). A two end-member mixing model showed that 82.0 ± 6.0% of POC originated from marine algae within the farm, much higher than that outside the farming area (66.1 ± 7.8%). Moreover, elevated DO saturation but relatively low Chl a concentration within the farm suggested continuous algae consumption following potential high productivity. The averaged δ13C values were similar among suspended POC, sinking POC, and sedimentary organic carbon within the farm, implying the fast export and burial of POC. This is likely due to the filter-feeding habits of mussels, who ingest fresh POC and then pack it as fecal pellets that rapidly settle into the sediment. This study sheds light on the distribution and sources of POM inside and outside the mussel farm on Gouqi Island, enhancing our understanding of the marine carbon cycle on shellfish farms and providing insights into the underlying biogeochemical processes.

Refining the Farm Aquaculture Resource Management Model for Shellfish Nitrogen Removal at the Local Scale

Nutrient-related environmental degradation in coastal waters is a continuing global problem. Bivalve shellfish farms show nutrient removal capabilities similar to some traditional management strategies and in some places have been incorporated into nutrient management programs to help achieve water quality goals. Bioextractive nutrient removal varies by farmed species and is influenced by environment parameters; thus, data and information for both are needed to estimate nutrient mitigation potential of shellfish farms. The Farm Aquaculture Resource Management (FARM) model, calibrated for farmed species, uses local environmental and farming practice data to simulate interactions between the farmed population and the local environment and to optimize cultivation practices for economic gain. We calibrated the model to predict nitrogen removal by Eastern oyster (Crassostrea virginica) farms with specific field and experimental data on oysters, their local environment, and farm practices in Long Island Sound, CT, USA. Previous FARM applications were not validated for nitrogen removal with local data. In the harvest when ready (HWR) model scenario (oysters are harvested when they reach harvest size), the farm removed 159 kg N ha−1 year−1 while the non-HWR scenario (all oysters are harvested at one time) removed 274 kg N ha−1 year−1. These estimates are within the range of previously reported in-water bioextraction studies in the Northeastern USA. The robust outputs from this validated model can be reliably used in marine spatial planning efforts and by nutrient managers to predict the nitrogen removal benefits that could be achieved through new or expanded eastern oyster farms in eutrophic environments.

One-year monitoring of potentially pathogenic microorganisms in the waters and sediments of the Lesina and Varano lagoons (South-East Italy).

In this study, two Mediterranean coastal lagoons (Lesina and Varano) of southern Italy, located in the north of the Apulia region, were investigated for the presence of Shiga toxin Escherichia coli (STEC) and potentially enteropathogenic Vibrio species in parallel with norovirus (NoV), hepatitis A virus (HAV), hepatitis E virus (HEV), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This study aimed to evaluate the presence of potentially pathogenic bacteria and viruses in the water and sediments of these ecosystems. From March 2022 to February 2023, a total of 98 samples were collected: 49 water samples and 49 sediment samples. STEC strains were isolated in three samples (3.1%), of which one (2%) was water (stx1 and stx2 positive) and two (4.1%) were sediment (both stx2 positive) samples. Vibrio spp. were detected in twenty samples (20.4%), of which nine were water (18.4%) and eleven were sediment (22.4%) samples. The species detected included V. parahaemolyticus, V. cholerae, and V. vulnificus. NoV was detected in 25 (25.5%) samples, while none of the water or sediment samples were positive for HAV, HEV, and SARS-CoV-2. The results of this study provide an overview of the presence of potentially pathogenic microorganisms in areas influenced by anthropogenic pressure. Monitoring the circulation of these pathogens could be useful to evaluate the water flowing into the lagoons, in particular discharge waters (i.e., urban, agricultural, and livestock runoff), considering the presence of fish and shellfish farms in these sites.

Assessing methods for detecting Alexandrium catenella (Dinophyceae) and paralytic shellfish toxins in Southeast Alaska.

Blooms of Alexandrium catenella threaten to disrupt subsistence, recreational, and commercial shellfish harvest in Alaska, as the paralytic shellfish toxins (PSTs) produced pose a serious public health risk and can lead to costly shutdowns for shellfish farmers. Current methods of PST detection in the region range from monitoring programs utilizing net tows to detect A. catenella to direct shellfish tissue testing via mouse bioassay (MBA) for commercial aquaculture harvest, as well as various optional testing methods for subsistence and recreational harvesters. The efficacy and feasibility of these methods vary, and they have not been directly compared in Southeast Alaska. In this study, we sought to assess and compare A. catenella and PST early detection methods to determine which can provide the most effective and accurate warning of A. catenella blooms or PST events. We found microscope counts to be variable and prone to missing lower numbers of A. catenella, which may be indicative of bloom formation. However, quantitative polymerase chain reaction (qPCR) significantly correlated with microscope counts and was able to effectively detect even low numbers of A. catenella on all sampling days. Paralytic shellfish toxin concentrations measured by enzyme-linked immunosorbent assay and MBA significantly correlated with each other, qPCR, and some microscope counts. These results show that qPCR is an effective tool for both monitoring A. catenella and serving as a proxy for PSTs. Further work is needed to refine qPCR protocols in this system to provide bloom warnings on an actionable timescale for the aquaculture industry and other shellfish harvesters. Integr Environ Assess Manag 2024;20:2189-2202. © 2024 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC). This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

Bacterial load mitigation of the shellfish Magallana gigas by the marine sponge Hymeniacidon perlevis (Montagu 1818)

Marine bioremediation consists in using filter-feeder organisms such as marine sponges in order to reduce the presence of coliforms and pathogens. In this study, the contamination of the Pacific shellfish Magallana gigas by both bacteria Escherichia coli and Vibrio aestuarianus was explored in vitro with or without the presence of the marine sponge Hymeniacidon perlevis. Results indicated that H. perlevis was able in vitro to reduce significantly faecal contamination and pathogen both in seawater and in shellfish. The clearance was comprised between 7 and 19 mL.h−1.g−1 of sponge (wet weight) depending on bacterial species. The risk of recontamination of seawater by the sponge itself was also studied. Those results confirm marine sponges and in particular the species H. perlevis might be promising candidate for bioremediation in shellfish farms.

Estimating growth using an ecophysiological and scope for growth model for the mussel Perna perna grown under suspended culture in Santa Catarina, Brazil

We present a dynamic simulation ecophysiological model for an important aquaculture mussel, Perna perna, grown under suspended culture in Santa Catarina, Brazil. The ecophysiological model was divided in four sectors; driving variables, feeding, energy reserve, and growth. This generated descriptions and explanations of the functions controlling feeding and metabolic responses to changing food availability and seawater temperature. The driving variables sector included time-series of seston variables likely to influence food and energy acquisition in mussels. It included relationships among seston variables to estimate the energy content of phytoplankton, the main component of mussel diet. The feeding sector described mussel suspension-feeding behavior measured using natural seston. Rates of filtration, rejection, ingestion, and absorption were directly related to the quantity and quality of available food. In the energy reserve sector, absorbed matter was transformed to absorbed energy using estimates of energy content of food provided in the driving variables sector. After accounting for the maintenance requirements of the mussels (heat loss and excretion), surplus energy, or the scope for growth, was directed to the growth sector. The growth sector included byssus, organic shell, and soft tissue production based on energy partitioning estimated from monthly measurements of somatic and reproductive tissue and shell growth. The model successfully predicted mussel growth during the study and provided estimates of the response to food acquisition, energy expenditure and allocation to growth. This was the first attempt to model the ecophysiology of this fast growing sub-tropical mussel. Given the capacity of this ecophysiological model to estimate growth of mussels, it has significant economic and environmental value in estimating carrying capacity to support sustainable management of shellfish farming in Brazil.

Environmentally Friendly and Efficient Methods for Mitigating the Density of Ascidian Fouling in Mediterranean Mussel Farming

Ascidian biofouling generates significant challenges to bivalve aquaculture. Their rapid spread across almost every available surface leads to increased maintenance costs and reduced yields in shellfish farming. In addition, ascidians may introduce pathogens or toxins, further compromising the health and marketability of bivalve stocks and thereby necessitating strict management strategies to manage these impacts. The aim of this study was the evaluation of different management practices for eliminating ascidian fouling and the identification of the best method for Mytilus galloprovincialis (Lamarck, 1819) aquaculture farms. The effects of different anti-fouling treatments as well as their interactive outcomes were examined by conducting two experiments. Various experimental procedures were applied, including the temporally differential washing of mussels, air exposure and immersion in 50 ppt and 70 ppt salinity solutions, as well as the combination of these applications. All treatments reduced the number of ascidian colonies on mussel socks but at varying proportions. Immersing mussel socks in a 70 ppt salinity solution followed by air exposure for 1 day was the most efficient method and led to a 93% eradication.

Preliminary study on the application of waste bivalve shells as biofiller for the production of asphalt concrete

The shells of molluscs are a common by-product of the aquaculture industry, and their management represents a significant environmental challenge. Although mollusc farming is considered a low-impact food production, improper shell management could make bivalve farming less environmentally efficient. To address this issue, research is exploring new approaches to reduce waste accumulation and convert shell waste into a valuable resource. The shells of bivalves are functional materials from biological waste, composed mainly of CaCO3, and can be used as secondary raw materials in various applications. In order to meet the demanding environmental target, the road sector is increasing the use of recycled materials in new construction or maintenance of old ones. The present work illustrates the results of several laboratory tests carried out to determine the physical and chemical properties of three different crushed bivalve shells waste for the application as filler in asphalt concretes. The present study highlighted the similarity of these materials with the limestone filler since no significant discrepancy between the mechanical (or technical) performance of the biofiller and the traditional limestone filler are detected through the test carried out, promoting their use in new asphalt concrete mixtures.

Lactic Acid Bacteria of Marine Origin as a Tool for Successful Shellfish Farming and Adaptation to Climate Change Conditions.

Climate change, especially in the form of temperature increase and sea acidification, poses a serious challenge to the sustainability of aquaculture and shellfish farming. In this context, lactic acid bacteria (LAB) of marine origin have attracted attention due to their ability to improve water quality, stimulate the growth and immunity of organisms, and reduce the impact of stress caused by environmental changes. Through a review of relevant research, this paper summarizes previous knowledge on this group of bacteria, their application as protective probiotic cultures in mollusks, and also highlights their potential in reducing the negative impacts of climate change during shellfish farming. Furthermore, opportunities for further research and implementation of LAB as a sustainable and effective solution for adapting mariculture to changing climate conditions were identified.