Mussel Farming Research Articles

The declining availability of wild mussel seed for aquaculture in a coastal upwelling system

A general decline in foundation species at the rocky intertidal has been observed during the last decades all around the world and primarily related to climate change. In agreement with that trend, the mussel aquaculture sector in Galicia (NW Spain), the main production area in Europe, has warned over the last years about a decline in the availability of wild mussel seed from the rocky coast. Here we compile for the first time, mussel seed collection reports by mussel farmers in Galicia for the period 2006–2021. We employed that dataset as a proxy of mussel recruitment evolution in the rocky shore for the last 16 years. Temporal analysis of our data confirmed the reported decline (-148 t yr-1), particularly pronounced from 2012 onwards. The data base also allowed us to analyze inter-annual variability according to both, climatic variations and management scenarios. Since cultivated mussels conform a meta-population with wild mussels from the rocky shore, alterations on the market preferences towards smaller individuals at harvest, could also contribute to a reduction in reproductive output. Our results show a decrease in life-time egg production under certain scenarios. Nonetheless, coastal upwelling seems to be the largest factor conditioning recruitment abundance, explaining as much as 60% of the variability observed. Decline on recruitment abundance was highly modulated by the observed increment in frequency of intense upwelling events, exceeding 500 m3 km-1 s-1 between July and November. Meridional winds also determined the spatial recruitment patterns, pointing to the large role of wind forcing on mussel larval dispersal. Our results highlights how alterations on upwelling regimes related to climate change can interact with mussel population dynamics and also condition aquaculture sustainability and food security.

Impacts of seeding density on the abundance and size of juvenile mussels and biofouling accumulation in Greenshell™ mussel aquaculture

Growth of the Greenshell™ mussel (Perna canaliculus) industry, New Zealand's most significant aquaculture sector, is limited by spat abundance in the early stages of the aquaculture cycle. However, there are few management techniques to improve spat production. Here, we tested the effects of seeding density (low: 257, mid: 515, and high: 1030 mussels per 10 cm of culture rope) – a putative method to manage spat seeding efficiency and yield – on the abundance and size of P. canaliculus spat at four depths at two sites in the Marlborough Sounds. We also recorded the abundance and size of blue mussels, Mytilus galloprovincialis, which are a problematic biofouling species, as well as the biomass and composition of the biofouling accumulating on mussel culture ropes under the same experimental treatments. Although the abundance of P. canaliculus was greatest at the highest seeding density (∼200 mussels per 10 cm of rope at 87 days), this seeding density also experienced the greatest losses. However, while fewer spat were lost from the low-density seeding treatment, the overall number of spat per 10 cm was significantly reduced, resulting in few operational gains in terms of biofouling reduction or spat size. Overall, the seeding density of suggesting that seeding density of ∼1030 spat per 10 cm of rope was the optimal density tested in this study and could be a useful target density for mussel farmers.

Using passive acoustic monitoring to assess the overlap between endemic endangered Hector's dolphin (Cephalorhynchus hectori hectori) and mussel farms in the Banks Peninsula Marine Mammal Sanctuary, New Zealand

Abstract Aquaculture has maintained a sustained growth trend over the last 50 years, worldwide and in Aotearoa New Zealand. This industry is known to have environmental consequences, such as impacts on benthos, water column and higher trophic levels. Some of these impacts have been thoroughly studied, while others, such as the effects on cetaceans, are not well understood. This study used passive acoustic monitoring (PAM) to assess, for the first time, the overlap between kūtai—New Zealand greenlipped mussel (Perna canaliculus)—farms and habitat use by endemic endangered Hector's dolphins (Cephalorhynchus hectori hectori) within the Banks Peninsula Marine Mammal Sanctuary. T‐PODs were deployed in six bays, three with mussel farms and three without, between 2018 and 2019. Occurrence of dolphins, expressed as ‘dolphin positive minutes per day’ (DPM/day), was modelled using generalized linear mixed models. Results showed a strong interaction between farm (presence/absence) and season (summer/winter), with fewer acoustic detections of dolphins in winter if farms were present. Furthermore, in bays with mussel farms, there were significantly more click train detections on the opposite side of the bay, compared to the side by the mussel farm. Considering that results from this study suggest potential displacement of the dolphins due to the mussel farms, the recommendation is a precautionary approach. Further expansion of aquaculture in Hector's dolphin habitat should be done carefully, taking into account their habitat use, and conducting intensive monitoring including a robust ‘before and after’ design prior to the establishment of new farms.

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.

The need for innovations to secure the future of artisanal mussel farming in the coastal sea of the Gulf of Trieste (Slovenia)

Mariculture along the Slovene coastline is mainly mussel culture operated as a family business; in one case, it is combined with sea bass farming. It started in the early 70 s with cultivation of Mediterranean mussels, while today, the two largest producers incorporate the cultivation of Venus clams and oysters as species with higher economic value on the market. Currently, all mussels and clams produced in Slovenia are sold in the Slovenian, Italian, Croatian and French markets. The production of Mediterranean mussels (Mytilus galloprovincialis) has increased steadily, with the main obstacles being a limited area for cultivation, occasional harmful algal blooms, predation by gilthead seabream and flatworms. In addition, more recent summer heatwaves negatively affected mussel production when seawater reached high temperatures at the thermal limits unsuitable for mussel growth. This study aimed to collect first-hand information about the current mussel production technology, processes and needs to identify opportunities for innovations that could benefit the entire sector (increased knowledge, production yield, reduced workload and effort with administrative issues). The study was based on a semi-structured questionnaire with the owners of mussel farms. Analysis of the questionnaire was supplemented with current knowledge from the field and provided comprehensive insight into a small sector of mussel farming along the Slovenian coast and its possible development in the future.

Hierarchical mussel farm reconstruction from video with object tracking

ABSTRACT As the mussel farming industry expands, particularly in regions such as New Zealand, there is a growing need for advanced monitoring and management solutions to ensure sustainability and operational efficiency. The current reliance on manual infrequent observation of aquaculture structures limits farmers' ability to monitor them in real time. Addressing these challenges, large-scale 3D reconstruction provides a practical solution by facilitating the creation of replicable depictions of mussel farm scenes and floatation buoys derived from recorded video, supporting off-site evaluation and enabling precise decision making. This paper introduces a novel approach to enhance the visualisation and monitoring of mussel farm floatation through a hierarchical reconstruction process. In contrast to earlier studies, we focus on recovering not only the overall environment (background) but also the finer details of key elements such as buoys to create a comprehensive representation of mussel farm geometry and appearance. We propose to segment the scene into the background and granular object instances and reconstruct them separately in a multi-stage process. The initial 3D scene reconstruction is performed using the Structure-from-Motion (SfM) technique, leveraging video footage captured by a vessel-mounted camera. This coarse reconstruction serves as the foundation for subsequent fine-grained enhancements. To recover finer details, object tracking is applied and the trajectories obtained are then conjunct with geometry triangulation to determine the real-world positions of individual buoys. A multiple-scale denoising method, grounded in dominant direction correlation, is implemented to eliminate non-reliable tracking objects and reduce reconstruction artifacts, ensuring the accuracy of the final results. This hierarchical reconstruction approach contributes to the advancement of mussel farm management by offering a powerful technology for comprehensive visualisation, enabling farmers to make informed decisions based on a detailed understanding of the mussel farm's geometry and dynamics.

A novel approach to assess temporal baseline levels of trace metal contamination in the mussel M. galloprovincialis in the Mediterranean, Marmara and Black Seas

This study reports, for the first time, the baseline levels for fifteen trace metals in M. galloprovincialis tissue from around the Mediterranean, Marmara and Black Seas. The environmental quality in the surrounding seawater was assessed i.e., a mussel farm was investigated by using CF and DC indices, and the water quality was qualified as good for the aquacultural activities. A strong Cu-regulation in the transplanted mussels was observed and it ranged between 3.20 and 3.60 μg/g d.w. The highest bioavailability and bioconcentration of the particulate Fe fraction could present a health risk to consumers with a low risk level (1 < THQ < 9.9). Cr is considered the limiting metal for mussel consumption (< 2 kg/day). The metal contamination gradient was assessed using TEPI and TESVI indices that identified seven reference stations on the large scale and revealed that Cd is the most investigated metal in the literature databases, and found that Pb was the most bioavailable contaminant in the areas examined.

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.

Multi-Spatial and Temporal Assessments of Impacts and Recovery of Epibenthic Species and Habitats Under Mussel Farms in the Marlborough Sounds, New Zealand

Multi-Spatial and Temporal Assessments of Impacts and Recovery of Epibenthic Species and Habitats Under Mussel Farms in the Marlborough Sounds, New Zealand

Introduction of the South American slipper limpet Crepipatella dilatata in Europe: Secondary spread in the Northeast Atlantic and first records for the Mediterranean Sea

The slipper limpet Crepipatella dilatata, native to Chile and Argentina, was introduced in north-western Spain in 2005 and since then has spread to the Galician and Cantabrian coasts. In this work, we provide the first molecularly validated record of an established population of C. dilatata in central Portugal (Aveiro), and of reproductive individuals (i.e. brooding females) of C. dilatata in the Mediterranean Sea, from three Italian mussel farms (in eastern Sardinia and northern Adriatic). DNA barcoding and phylogenetic analyses based on mitochondrial markers indicate that limpets from Italian farms belong to the C. dilatata ‘clade1’, whereas limpets collected in Aveiro cluster within the C. dilatata ‘clade2’. All these limpets share the same COI haplotypes with introduced populations from Galicia. The arrival of C. dilatata to Europe is undoubtedly due to transoceanic live mussel trade from southern Chile to Galicia. Mussel trade and farming are also the most likely drivers for the post-border dispersal of C. dilatata from Spain to Portugal and to Italy. Several countries have a potential role as a hub for the primary and secondary dispersal of slipper limpets towards and within Europe. This calls the attention for future research focused on assessing the current occurrence and ecological impact of established populations of slipper limpets within and nearby mussel farms along the eastern Atlantic and Mediterranean coasts.

Dusky dolphin (Lagenorhynchus obscurus) habitat use in a mussel farming region and changes over time

ABSTRACT Information on marine mammal habitat use in coastal areas can provide a better understanding of anthropogenic effects on species. Admiralty Bay, New Zealand has extensive near-shore mussel farms and is an important dusky dolphin (Lagenorhynchus obscurus) foraging habitat. Prior dusky dolphin research indicated a declining trend in regional abundance from the late 1990s to mid-2000s. We describe dusky dolphin behaviour, habitat patch use and movement patterns in Admiralty Bay in 2011–2012 and compare findings to previous research to capture long-term trends. Sampling methods included small-boat group follows and photo-identification and shore-based theodolite tracking. Dolphin encounter rate, mean group size, and individual resighting rate showed a negative trend from previous years. Coordinated prey ball herding, a foraging technique documented in previous years, was rarely observed during this study. Dolphins were more likely to forage near farms (excluding specialised prey herding), though they seldom entered farms. Near shore, swimming speed was slower, reorientation rate was higher, and linearity was lower in the presence of farms than in their absence. This research builds upon prior studies, suggesting a continued decline in dusky dolphin presence, and highlights differences in habitat patch use in a human-altered ecosystem.

The aggregation effect of offshore mussel farming on pelagic fishes

AbstractThe increase in hard artificial structures in the marine environment is contributing to ocean sprawl. As well as adding hard structure to the seabed, mussel aquaculture adds rope droppers and anchor lines to the water column, where such structure would otherwise be absent. This paper aims to monitor the effects of mussel headlines on the pelagic fish community over time, as well as to investigate whether there is an interaction between the age of cultivated mussels with the number of epibiota species and the abundance of pelagic fishes. Two surveys were carried out: a time series monitoring survey to assess whether the mussel headlines change the surrounding fish species relative to control areas over time, and a fish aggregation device effect survey to investigate whether older and larger mussels support greater abundances of pelagic fishes and epibiota. The most abundant fish species was Atlantic horse mackerel, Trachurus trachurus, with significantly greater numbers recorded around ropes growing older mussels. Results from the surveys show that the physical farm infrastructure has provided a substrate for colonisation by a variety of epibiota: A total of 21 species were recorded growing on the mussel ropes. Furthermore, the older and larger the mussels become, the greater the numbers of epibiota taxa that can colonise, coupled with a greater abundance of pelagic fish recorded around the ropes. The sustainable development of offshore Blue Industries is essential to produce renewable resources. This study brings essential evidence for marine managers and regulators that offshore mussel farming can provide benefits for pelagic and benthic species of both conservation and commercial importance while producing sustainable protein to feed a growing population.

Transitioning from wild seed fishery to Seed Mussel Collectors (SMCs): Reviewing the efficiency of collectors for seed provisioning in mussel bottom culture

The availability of mussel seed is a critical aspect in mussel farming. Since 2009, the Dutch mussel sector has been transitioning from wild seed fishery to suspended seed collectors (Seed Mussel Collectors, or SMCs). Collector systems using either ropes or nets as settlement substrate are placed in Oosterschelde Bay, the Wadden Sea, and the North Sea annually. We analyzed detailed harvest data from 2010 until 2022, to investigate the efficiency of different systems, identify differences between years and areas, and assess how production can be optimized. Additionally, numerical density, biomass, and shell lengths of mussels from 0.375 mm shell length were recorded on SMC ropes at one SMC location during a full growth season to evaluate biomass-density relations and assess the process of self-thinning on the ropes. Total harvest of SMC mussel seed increased over the period 2010–2022, from 8.0 ×106 kg to 21.0 ×106 kg fresh weight. Harvest per unit substrate was remarkably stable over the years across sites, with a lower mean in Oosterschelde Bay (∼2.56 kg m−1) than in the Wadden Sea (∼3.28 kg m−1). Ropes were found to provide a greater yield per unit area than nets, but nets are less labor-intensive to use. Occurrence of density-dependent growth on the ropes was indicated by the allometric relation between mussel biomass and mussel density. A positive relation between density and growth rate suggested that competition increased with growth rate. In the growth data covering a full SMC season, we first observed a rapid numerical increase as newly settled mussels continued to grow into the measured size range. This was followed by a period of rapid numerical reduction and increasing biomass, indicating self-thinning. Finally numerical reduction stabilized and biomass increase accelerated coupled with comparatively slower shell length increase. The self-thinning occurred between approximately 2.3 mm and 11.6 mm mean shell length. Our analysis of 12 years of production data shows that SMC seed is a robust and annually more reliable alternative to wild capture fishery as a seed provisioning resource for mussel culture. Production per unit substrate does not appear to be easily amenable to further improvement. Production per unit area showed no indication of overstocking on the scale of the SMC plots, suggesting that production gains could be made by increasing substrate density.

Degradation of plastic materials in the marine environment: A mussel farm as a case study for the development of alternative mussel nets

Currently, mussel farming uses of traditional plastic nets that accumulate on beaches and on the seabed in the event of breakage and accidental dispersion, contributing to the marine litter issue. An attempt is being made to replace the polypropylene nets with alternative materials to make the aquaculture full production cycle more sustainable. However, alternative materials need to be characterised both functionally and environmentally. This article describes a characterisation study in which plastic materials were exposed for approximately three years to the marine environment in a bay dedicated to mussel farming to provide data on the degradation behaviour of the selected polymers for eco-design purposes. Samples of the different materials, in the form of 3-mm thick dumbbells, were placed on the seabed at a depth of 12 m and in the water column at 2 m below the sea surface. At different time periods (after 6, 15, 24, 32 months), the samples were recovered, their mass and thickness were measured, and the mechanical properties were characterised. The results lead to the identification of some materials as sufficiently resistant to deterioration and therefore possible candidates for the application. Other materials generally used to make bags and films showed a very fast degradation and therefore do not seem to meet the performance requirements for mussel farming. The methodology used in this study seems suitable for conducting long-term exposure tests on locations of interest and collecting specific data for eco-design purposes before the application of the product on the markets.

Feasting in mussel farms fattens up snapper (Chrysophrys auratus) compared to snapper in adjacent natural habitats

AbstractThe presence of wild fish in and around aquaculture habitats is often assumed a response to food resources within these habitats, either from input feed, the presence of cultured species, and/or the assemblage of biofouling that naturally colonises aquaculture structures. The nutritional quality of the food resources consumed by wild fish in aquaculture habitats is also important in determining their nutritional condition and subsequent productivity. Few studies have investigated the nutritional quality of prey in aquaculture habitats, and these have mostly focused on fed aquaculture by tracking manufactured fish pellets into the diets of wild fish. However, in non‐fed aquaculture, the assemblage of cultured and biofouling species may also provide a nutritional benefit to fish feeding in these habitats. The Australasian snapper, Chrysophrys auratus, are commonly present as adults within coastal mussel farms in New Zealand and tend to become a resident species. This study investigated the nutritional quality of the gut contents of snapper in soft‐sediment habitats within and outside of New Zealand green‐lipped mussel farms. Total lipid, protein, carbohydrate and total calorific content were measured from the gut contents of snapper sampled from mussel farm and natural (i.e. control) habitats. Snapper in mussel farms had double the dietary intake of lipid (16% vs. 8%) from consuming lipid‐rich bivalves and barnacles which are in abundance in mussel farms. Higher lipid intake can contribute to improved nutritional condition, reproduction and growth in snapper. However, the higher dietary lipid intake of snapper in mussel farms did not increase their overall body condition (i.e. Fulton condition index). This may be due to the coarse nature of this measure, or the use of the additional lipid in more rapid somatic growth or reproductive outputs, possibilities that warrant examination through further research. Overall, this study shows for the first time the potential ecosystem benefits of shellfish aquaculture in provisioning nutritionally valuable prey for coastal fish populations.

Risk level assessment of typhoon-induced wave fields around a large-scale suspended mussel farm

Suspended shellfish aquaculture, utilizing longlines and buoys fixed on the sea surface, is a crucial source of global seafood. However, typhoons, as the most common disasters in coastal regions, can generate massive waves and pose a threat to the safety of suspended aquaculture facilities. Therefore, it is essential to investigate the risk levels associated with suspended aquaculture farms during typhoon waves. The example of a large-scale suspended mussel farm in the East China sea was examined in this study. The wave conditions under extreme wind conditions (25m/s) and different typhoon paths were predicted using the SWAN model and modeled results compared well with the observed wave and wind data. The results indicated that when the center of the east-side typhoon was located at the same latitude as the farm, it will face the highest risk level. However, for the west-side and intermediate sweeping typhoons, the risk level reached highest in the farm, when the typhoon center is lower than the latitude of it. Under the combined effects of wind fetch and topography, the risk level in the southeast farming area of the island is the highest under different wind conditions. The farms to the northwest of the island face a higher risk level during the passage of east-side sweeping typhoons, while the southern farms of the island experience an elevated risk level during the west-side and intermediate sweeping typhoons. It is suggested that farming regions with lower risk levels are more conducive to the cultivation of species with longer culture cycles. Conversely, regions considered at higher risk are more suitable for species with shorter culture cycles. The study affords a reference for the optimization and insurance of suspended aquaculture farms.

Impacts of large-scale suspended mussel farm on seston depletion

The productivity of a suspended mussel farm depends on the abundance of naturally available food. This study constructs a tracer decay model that incorporates mussel filtration and integrates it with a well-established 3D ocean circulation model to examine the spatiotemporal variation of seston depletion at a large-scale suspended mussel farm on Gouqi Island, located offshore in the East China Sea. A novel Wirewalker ocean-wave-powered vertical profiling system was deployed to monitor chlorophyll-a concentration at the edge of the mussel farm. The observed profiles of chlorophyll-a concentration revealed that the current exiting the farm during ebb tide is associated with a lower concentration compared to the current entering the farm during flood tide. This suggests that the filter feeding activity of mussels within the farm is primary contributor to this reduced chlorophyll-a concentration. This finding is consistent with the tracer model results, which indicates a higher tracer concentration entering the farm and a lower tracer concentration exiting it. The model results suggest that the blocking effect of the farm can significantly exacerbate seston depletion, particularly during neap tide as opposed to spring tide. The interplay of tidal characteristics and topography has resulted in two areas that are particularly vulnerable to seston depletion: one centrally situated within the mussel farm, and another near the islands. However, it is possible to alleviate seston depletion by aligning the waterway within the farm with the major axis of the tidal ellipse. Consequently, it is crucial to consider tidal conditions surrounding the farm for optimal farm layout design, increased production, and enhanced stock quality in shellfish farms facing seston depletion.

Assessing the impact of an offshore longline mussel farm on local water circulation in a highly hydrodynamic energetic bay

Thought to be a sustainable choice, molluscs are the most consumed aquaculture foods after finfish. The expansion of the mussel aquaculture industry offshore reports lower environmental impacts compared to inshore farms. Although an offshore location has the potential to reduce a farm's ecological impacts, the effect of large developments on water currents is still not fully understood. High hydrodynamic regimes can influence the dispersion of farm biodeposits, organic loading, flow alterations with the potential to impact water residence time, particle and sediment dispersal (including larvae and biodeposits) and seabed sediment resuspension, which in turn, can have ecological impacts. Farm-induced flow changes of the UK's first large scale suspended longline mussel farm were assessed by a combination of oceanographic mooring and vessel-mounted Acoustic Doppler Current Profiler (ADCP) measurements. Data was separated by upstream and downstream according to the direction of the flow in relation to the farm. M-ADCP results showed a 28% decrease current velocities within the farm's boundaries, demonstrating within-farm current attenuation produced by mussel ropes drag. Flow was then redistributed above and beneath the farm showing velocity increases of 66% and 7% respectively, resulting in above-farm flow acceleration and downwelling (with up to 171% increase in near-seabed velocities compared to sea surface velocities). However, overall mean downstream sea surface velocities decreased by 63%. An overall 21% increase in near-seabed velocities showed the farm's effect on near-bed currents, the opposite to what is naturally achieved by seabed friction. This was further measured by VM-ADCP results also showing secondary flow acceleration at the farm's flanks and increased near-headline flow perturbations of up to 80% mean u velocities over a small horizontal scale (0.5 km), further demonstrating the effects of the farm on the local circulation. Through-farm surface current velocities (waves) were reduced by up to 72%. Flow changes were localised and dependent on the different tidal phases, the farm's design and, the abundance of mussel ropes providing drag.

Signature of the anthropogenic impacts on the epipelagic microbiome of the North-Western Adriatic Sea (Mediterranean Sea)

IntroductionIn our paper, we explored the impact of different anthropogenic stressors, namely, mussel farming, methane extraction platforms, and summer mass tourism, on the epipelagic microbiomes of the North-Western Adriatic Sea.MethodsBy 16S rRNA gene sequencing, we provided the epipelagic microbiome layout from selected sites corresponding to each of the considered impacts. As an unimpacted reference, we used already published 16S rRNA sequencing data.ResultsAccording to our findings, each one of the anthropogenic stressors resulted in a peculiar increase of specific epipelagic microbial components, including copiotrophic R-strategists and host-restricted bacteria, as well as some pathobiome components, the latter being detected exclusively in impacted sites. Particularly, potentially harmful pathogenic species such as Legionella impletisoli and Staphylococcus epidermidis have been detected in proximity to the mussel farms, and Escherichia coli and Campylobacter ureolyticus were present close to the methane extraction platform and at the summer mass tourism site, respectively. Particularly, C. ureolyticus is an emerging human gastrointestinal pathogen, capable of destroying intestinal microvilli.DiscussionIn addition to providing evidence supporting the existence of recognizable and impact-driven fingerprints on the epipelagic marine microbiome peculiar to the different anthropogenic stressors, our findings also raise concern about the ecological relevance of the observed changes, in terms of possible loss of ecosystem services and also for the potential release of pathogenic microorganisms in the environment.

Characteristics and distribution model of wind and wave in Shengsi mussel culture area under the impacts of tropical cyclones

Abstract The primary industry in Shengsi County, Zhejiang Province, China, is the raft-based cultivation of Mytilus coruscus, which is highly sensitive to wind and wave disturbances. This study aims to understand the characteristics of tropical cyclones along Zhejiang's coast, their relation to climate change, and the impact of wind and waves on Shengsi mussel farming during cyclones. Analyzing data from 2000 to 2018, including tropical cyclone paths, wind and wave data, and mussel farming statistics, the research identifies four cyclone path types, with the peak prevalence from July to September. Annual cyclone energy fluctuates, peaking in August. In the cyclone impact zone, the average wind speed is 24.59 m/s. Type D cyclones have the most significant impact. A linear relationship exists between cyclone center distance and wind speed/wave height. Extreme wind speed and wave height follow the Gumbel joint probability distribution. Since 2000, the Shengsi mussel farming area experienced an 11.20-year return period for wind and waves from the strongest cyclone, Muifa. Given the recurrence period of Muifa intensity cyclones in 2020 and the following years, the study recommends disaster preparedness for the Shengsi mussel farming area and emphasizes the role of mutual aid insurance.