Solar Saltworks Research Articles

Unique Features of Extremely Halophilic Microbiota Inhabiting Solar Saltworks Fields of Vietnam.

The artificial solar saltworks fields of Hon Khoi are important industrial and biodiversity resources in southern Vietnam. Most hypersaline environments in this area are characterized by saturated salinity, nearly neutral pH, intense ultraviolet radiation, elevated temperatures and fast desiccation processes. However, the extremely halophilic prokaryotic communities associated with these stressful environments remain uninvestigated. To fill this gap, a metabarcoding approach was conducted to characterize these communities by comparing them with solar salterns in northern Vietnam as well as with the Italian salterns of Motya and Trapani. Sequencing analyses revealed that the multiple reuses of crystallization ponds apparently create significant perturbations and structural instability in prokaryotic consortia. However, some interesting features were noticed when we examined the diversity of ultra-small prokaryotes belonging to Patescibacteria and DPANN Archaea. Surprisingly, we found at least five deeply branched clades, two from Patescibacteria and three from DPANN Archaea, which seem to be quite specific to the Hon Khoi saltworks field ecosystem and can be considered as a part of biogeographical connotation. Further studies are needed to characterize these uncultivated taxa, to isolate and cultivate them, which will allow us to elucidate their ecological role in these hypersaline habitats and to explore their biotechnological and biomedical potential.

Extreme halophilic Archaea: Halobacterium salinarum carotenoids characterization and antioxidant properties

Important marine microorganisms are resources of renewable energy that may face global population growth and needs. The application of biomass metabolites, such as carotenoids and their derivatives, may solve some agro-food health problems. Herein, a new halophilic Archaea Halobacterium salinarum producing carotenoid was screened from a Tunisian solar Saltworks (Sfax). The identification of the carotenoid pigments was carried out using HPLC-MS/MS. The predominant pigments produced by this Halobacterium were bacterioruberin and its derivatives and the carotenoids production was found to be of 21.51 mg/mL. Moreover, the data revealed that the carotenoids extract exhibited a high antioxidant activity across four oxidizing assays. The present results suggested that carotenoids extracted from halophilic Archaea are interesting sources of natural antioxidants for future innovative applications in agro-food, cosmetic and health fields.

The taxonomic status of Artemia monica (Crustacea: Anostraca)

Abstract Species are fundamental units of nature that need proper identification in order to assess and conserve biodiversity. Artemia is a model crustacean for population analysis and comparison in regionally endemic sexual species and parthenogenetic lineages distributed in hypersaline lakes, lagoons, and solar saltworks scattered in arid and semi-arid areas worldwide. The taxonomy of two American Artemia species has been controversial: Artemia monicaVerrill, 1869, adapted to the carbonate-rich conditions of Mono Lake (CA, USA), and Artemia franciscanaKellogg, 1906, a species broadly distributed in the Americas. The former species has been studied little, despite being listed as threatened in the IUCN Red List. In contrast, the latter has been studied extensively, is broadly distributed in the Americas, and has become established as a non-native invasive species in Europe, Asia, Africa, and Australia. Given the need to conserve A. monica, the intraspecific diversity of invasive A. franciscana, and the local species in areas invaded by this species, we reconsider their biodiversity and taxonomic status currently threatened by synonymization. In conclusion, A. monica and A. franciscana should be treated as two separate species that are isolated both ecologically and reproductively.

Selective recovery of boron, cobalt, gallium and germanium from seawater solar saltworks brines using N-methylglucamine sorbents: Column operation performance

The European Union (EU) identified a list of Critical Raw Materials (CRMs) crucial for its economy, aiming to find alternative sources. Seawater is a promising option as it contains almost all elements, although most at low concentrations. However, to the present, the CRMs' recovery from seawater is technically and economically unfeasible. Other alternatives to implement sea mining might be preferred, such as reverse osmosis brines or saltworks bitterns (after sodium chloride crystallisation). The CRMs' extraction in a selective way can be achieved using highly selective recovery processes, such as chelating sorbents. This study focuses on extracting Trace Elements (TEs) from solar saltworks brines, including boron, cobalt, gallium and germanium, using commercial N-methylglucamine sorbents (S108, CRB03, CRB05). The application of these sorbents has shown potential for boron recovery, but their selectivity for cobalt, gallium, and germanium requires further investigation. This research aims to assess these sorbents' kinetics and column mode performance for TEs recovery from synthetic bitterns. Boron and germanium were rapidly sorbed, reaching equilibrium (>90 %) within 1 h, except for S108, which took 2 h. In column mode, 20–25 pore volumes of bittern were treated to remove boron and germanium, but competition from other elements reduced treatment capacity. An acidic elution (1 M hydrochloric acid) allowed to elute them (>90 %), reaching concentration factors for germanium and boron of 35 and 11, respectively, while cobalt and gallium had less affinity for the sorbents. In addition, the experiments performed were fitted by a mass transfer model to determine the equilibrium constants and selectivities. Therefore, bittern mining has been proven as a secondary/alternative source to obtain CRMs, which can lead the EU to a position in which its dependence on other countries to obtain these raw materials would be decreased.

In-depth insights on multi-ionic transport in Electrodialysis with bipolar membrane systems

Electrodialysis with Bipolar Membranes (EDBM) has become a key technology for valorising waste brine streams as a new chemical production route. Even though its application has been widely studied using single electrolyte solutions (e.g., NaCl or Na2SO4), there is still a lack of knowledge about using multi-ionic mixtures. For the first time, this work aims to evaluate the EDBM performance when treating synthetic solutions mimicking the waste brines produced in a integrated process for the valorisation of solar saltworks bitterns. The behaviour of a lab-scale EDBM unit was assessed using SUEZ ion exchange membranes (IEMs), operating at 300 A m−2, and the ion transport through IEMs was investigated, based on the calculation of apparent transport numbers and selectivities.The results highlighted that multi-ionic solutions barely affected the production of hydroxide ions. Chlorides were transported up to 7 times faster than sulphates across the anion-exchange membranes, while the cation-exchange membranes exhibited slightly higher selectivity for potassium than for sodium (∼1.2). The current efficiencies ranged between 70 % and 80 %, while a minimum specific energy consumption of 1.60 kWh kg-1NaOH was obtained for the most concentrated brine at 1 mol L-1 OH–.These results provide novel and valuable information to support the development and implementation of EDBM as a sustainable technology for supporting a resource-efficient and competitive economy through on-site and delocalized chemicals production routes.

White stork movements reveal the ecological connectivity between landfills and different habitats

BackgroundConnections between habitats are key to a full understanding of anthropic impacts on ecosystems. Freshwater habitats are especially biodiverse, yet depend on exchange with terrestrial habitats. White storks (Ciconia ciconia) are widespread opportunists that often forage in landfills and then visit wetlands, among other habitats. It is well known that white storks ingest contaminants at landfills (such as plastics and antibiotic resistant bacteria), which can be then deposited in other habitats through their faeces and regurgitated pellets.MethodsWe characterized the role of white storks in habitat connectivity by analyzing GPS data from populations breeding in Germany and wintering from Spain to Morocco. We overlaid GPS tracks on a land-use surface to construct a spatially-explicit network in which nodes were sites, and links were direct flights. We then calculated centrality metrics, identified spatial modules, and quantified overall connections between habitat types. For regional networks in southern Spain and northern Morocco, we built Exponential Random Graph Models (ERGMs) to explain network topologies as a response to node habitat.ResultsFor Spain and Morocco combined, we built a directed spatial network with 114 nodes and 370 valued links. Landfills were the habitat type most connected to others, as measured by direct flights. The relevance of landfills was confirmed in both ERGMs, with significant positive effects of this habitat as a source of flights. In the ERGM for southern Spain, we found significant positive effects of rice fields and salines (solar saltworks) as sinks for flights. By contrast, in the ERGM for northern Morocco, we found a significant positive effect of marshes as a sink for flights.ConclusionsThese results illustrate how white storks connect landfills with terrestrial and aquatic habitats, some of which are managed for food production. We identified specific interconnected habitat patches across Spain and Morocco that could be used for further studies on biovectoring of pollutants, pathogens and other propagules.

Numerical modelling of a solar salt pan for improved salt production at Lake Katwe, Uganda

The solar salt pans at Lake Katwe are set up haphazardly without any scientific guidelines which compromises the annual throughput from the solar salt works. To improve on the design of the salt pans, the heat transfer dynamics of the salt pan have been numerically and experimentally studied in this study. A representative salt pan located at the shores of the lake Katwe with a surface area of 62 m2 and a depth of 0.2 m was used in this study. The numerical model was implemented in the OpenFOAM software where a 3D heat transfer salt pan model was studied using the Finite Volume Method under Lake Katwe climatic conditions. The model was governed by continuity, salt concentration, momentum, energy equations and the Boussinesq approximation. A field experiment that determined the temperature variation with depth was carried out. The correctness of the model results was verified against experimental data. The numerical simulation model revealed a salt pan brine temperature increase with time and the salt concentration significantly remained constant with time. The salt pan brine temperature increased from 303 K to 319.5 K after 5 h of the simulation time. The model and the experimental salt concentration and temperature profiles were found to be in a good agreement. The sensitivity analysis on the effect of the salt pan depth on brine temperature was studied. It was revealed that the shallower the salt pan, the higher the rate of heat gain. This study revealed that an optimum salt pan depth to yield a higher salt quantity under Lake Katwe climatic conditions was at 0.1 m.

Sustainable recovery of critical elements from seawater saltworks bitterns by integration of high selective sorbents and reactive precipitation and crystallisation: Developing the probe of concept with on-site produced chemicals and energy

The availability of raw mineral resources containing elements included in the Critical Raw Materials (CRMs) list is a growing concern for the European Union. Sea mining has been identified as a promising secondary source. In particular, brines obtained in solar saltworks (bitterns) contain relevant amounts of valuable CRMs such as Mg(II), B(III), other alkaline/alkaline earth metals (Rb(I), Cs(I), Sr(II)) and transition/post-transition elements (Co(II), Ga(III), Ge(IV)). However, the low concentration of some of these elements (µg/L) requires an effort to develop recovery routes that are sustainable and economically feasible where the required chemicals and energy are produced on-site from the saltworks bitterns (i.e. HCl and NaOH). Even the conventional recovery processes such as ion exchange, sorption and precipitation, which have proved to be competitive for metals recovery, are challenged in the case of Trace Elements (TEs). This work studies the recovery of TEs included in the CRMs list from saltworks bitterns after ion exchange processes. First, batch crystallisation and reactive precipitation were tested for some target elements in single-component solutions: Sr(II), Co(II), Ga(III), Ge(IV) and B(III). Then, the experiments were carried out with multi-component synthetic solutions assuming different scenarios of bittern streams coming out a selective extraction stage using sorption and ion exchange processes. The targeted elements were recovered except for Ge(IV), where alternative routes need to be evaluated, as its precipitation involves the use of tannic acid or sulphide solutions that could not be produced from the bitterns. However, a further concentration step would be necessary to achieve element concentrations closer to the mineral phases saturation. Moreover, model simulations were performed using the PHREEQC program, which provided a good prediction of the experimental trends obtained in most cases.

Mapping and Assessment of Landscape’s Capacities to Supply Ecosystem Services in the Semi-Arid Coast of Brazil—A Case Study of Galinhos-Guamaré Estuarine System

Wetlands are periodically flooded terrestrial and aquatic environments, which provide benefits to a community known as ecosystem services (ESs). This research identified, classified, and spatialized the level of relevance of ecosystem services provided by wetlands in the Galinhos-Guamaré semi-arid estuarine system, State of Rio Grande do Norte, Northeast Brazil. ESs were analyzed using the Common International Classification of Ecosystem Services (CICES), v.4.3, and geographic information system (GIS) using a mosaic of Sentinel-2A images. The services provided by wetlands were classified into provision, regulation and maintenance, and cultural sections, with six divisions, 12 groups, and 22 classes being identified. The capacity of a number of wetlands to provide services was identified in 34 mangrove forests, 32 estuaries, 30 tidal flats, 26 solar saltworks, 23 apicum (tidal flats), and seven in shrimp ponds. However, it is noteworthy that these habitats are associated with ecosystems with great ecological, socioeconomic, and cultural importance, where the general approach presented here requires more detailed research in each macrohabitat, which should be considered as a priority for conservation.

Mining minerals and critical raw materials from bittern: Understanding metal ions fate in saltwork ponds

Seawater represents a potential resource for raw materials extraction. Although NaCl is the most representative mineral extracted other valuable compounds such as Mg, Li, Sr, Rb and B and elements at trace level (Cs, Co, In, Sc, Ga and Ge) are also contained in this “liquid mine”. Most of them are considered as Critical Raw Materials by the European Union. Solar saltworks, providing concentration factors of up-to 20 to 40, offer a perfect platform for the development of minerals and metal recovery schemes taking benefit of the concentration and purification achieved along the evaporation saltwork ponds.However, the geochemistry of these elements in this environment has not been yet thoroughly evaluated. Their knowledge could enable the deployment of technologies capable to achieve the recovery of valuable minerals. The high ionic strengths expected (0.5–7 mol/kg) and the chemical complexity of the solutions imply that only numerical geochemical codes, as PHREEQC, and the use of Pitzer model to estimate the activity coefficients of the different species in solution can be adopted to provide valuable description of the systems.In the present work, for the first time, PHREEQC Pitzer code database was extended to include the target minor and trace elements using Trapani saltworks (Sicily, Italy) as a case study system. The model was able to predict: i) the purity in halite and the major impurities contained, mainly Ca, Mg and sulphate species; ii) the fate of minor components as B, Sr, Cs, Co, Ge and Ga along the evaporation ponds. The results obtained pose a fundamental step in critical raw materials mining from seawater brine, for process intensification and combination with desalination.

Long-term artificial seawater irrigation as a sustainable environmental management strategy for abandoned solar salt works: The case study of Agua Amarga salt marsh (SE Spain)

Groundwater abstraction is among the main anthropogenic causes of wetland desiccation worldwide, and corrective measures must be taken to avoid degradation of this valuable ecosystems. A case study is the Agua Amarga salt marsh (≈180 ha) (SE Spain). Agua Amarga includes a solar saltwork pond network in operation between 1925 and 1975, when it was abandoned, and the ponds were colonized by salt marsh vegetation. In 2008 two desalination plants were operating in the marsh vicinity, which were supplied with groundwater. To mitigate the possible negative impact on the salt marsh ecosystem due to groundwater drawdown, in 2009 a sea water irrigation program was implemented. This paper summarizes the results of a ten-year monitoring program (2010–2020) to evaluate the effects of the irrigation program on groundwater levels and quality, soil salinity and moisture, and vegetation cover. During this period, average groundwater level was 2.5 m below the surface and around 1 m deep near the irrigated ponds. Groundwater salinity was not affected outside the saltmarsh, but inside, where the saltworks caused values to rise above 300 mS/cm, it decreased more than 150 mS/cm in some 20 m deep piezometers. Between 2012 and 2020, vegetation cover increased between ≈10 and ≈25 %, with halophyte species such as Arthrocnemum macrostachyum and Sarcocornia fruticosa being the most favoured. In areas with prolonged flooding, Ruppia maritima, a plant species that lives submerged in saline water, was found. In the irrigated areas, soil electrical conductivity (1:5 soil:water extracts) decreased from ≈7-14 mS cm-1 to ≈2-6 mS cm-1. We present an example of sustainable actions in a coastal wetland, where the exploitation of water resources in semiarid areas is combined with promoting natural habitats.

Characterization and biomedical application of Tetradecamethylcycloheptasiloxane, a silicone-type biosurfactant produced by Streptomyces castaneoglobisporus AJ9 isolated from solar salt works

Characterization and biomedical application of Tetradecamethylcycloheptasiloxane, a silicone-type biosurfactant produced by Streptomyces castaneoglobisporus AJ9 isolated from solar salt works

Factors Affecting Technology Adoption of Geoisolator on Solar Saltworks in East Java Province

Large quantity and high-quality salt are demanded in Indonesia, yet the quality of salt produced by farmers is still low. Increasing salt quantity and quality is possibly done through the implementation of geoisolator technology. This study aimed to investigate factors affecting the decision of salt farmers to adopt geoisolator technology. The study was conducted at the salt production center in Madura Island. A survey on salt farmer was carried out during August-September 2018. A total of 190 respondents consisted of 131 salt farmers who adopted geoisolator technology and 59 traditional salt farmers were selected as a sample in this study. Factors affecting farmer decision to adopt geoisolator technology was analyzed using logit (logistic regression) model. The result of this study showed that the decision of salt farmer to adopt geoisolator technology was affected by the number of productive-age family members and the number of dependent family members, land area, farmer participation in the group, farmer participation in extension. Enhancement in the adoption of geoisolator technology needs synergy between extension agent and salt farmer group so that the mentoring process and knowledge transfer will be achieved.

Sedimentological implications of microbial mats, gypsum, and halite in Dhahban solar saltwork, Red Sea coast, Saudi Arabia

Microbial mats and gypsum exist in concentration ponds due to the first stage of evaporation, whereas halite is present in the crystallizers with continuous seawater evaporation, in the saltwork of Dhahban area, north of Jeddah city, Saudi Arabia. Several gypsum and halite facies types are distinguished in response to differences in microbial activity, salinity, topography of the ponds, water depth and wave energy. Two gypsum facies are recognized; planar–wavy gypsum microbialite and domal gypsum stromatolite at the relatively low salinity, inlet margin, and the relatively high salinity, outlet margin of the concentration ponds, respectively. They consist of fine and coarse, fibrous and swallowtail twin gypsum crystals that nucleate on the surface of microbial mats. Halite crystallizes at the brine surface as floating cumulates and rafts, and at the bottom of the ponds as vertically elongated chevrons and cornets. Lateral chevrons grow at the bottom of the ponds and at the brine surface in association with vertical chevrons and halite spheroids, respectively. Fluid-inclusion bands are regular and symmetrical in halite crystals, or show asymmetrical and indistinct layers in chevrons, and as a continuous layer over top of cumulates and rafts. This study suggests that saltworks represent a valuable ‘laboratory’ for the study of the primary depositional features of gypsum and halite crystals that are related to microbial activity, salinity, depth and/or energy conditions. The results can be used to infer physical energy conditions for deposition of gypsum and halite in ancient evaporitic basins.

An evaluation of the economic viability of environmental offsets in the saltworks industry

ABSTRACT: The extraction of sea salt depends on the occupation of large areas at the estuary banks, many of them inserted in Permanent Preservation Areas (PPAs). Thus, the objective was to evaluate the economic viability of Environmental Offsets (EO) as an alternative to the unoccupied PPAs in the saltworks. In order to do so, 27 solar saltworks installed in the region of the Brazilian White Coast were evaluated for the occupation of PPAs - measured using images from satellite, georeferenced, vectored with corresponding PPA bands generated - and estimated to EO (Impact Degree x Sum of the investments necessary to implement the project) and Economic Impact (Net Present Value, with long-term interest rate of 7%) of vacating PPAs. It was considered that EO was feasible whenever the costs resulting from it were lower than the economic impact caused by the vacancy of the PPAs. The PPAs were tthe productive area of the saltworksthat occupied 13.70% of PPAs. For all the evaluated enterprises the value corresponding to EO was lower than the Economic Impact resulting from the vacancy of the PPAs. Thus, EO is an economically viable and more attractive alternative to the eviction of PPAs by the saltworks industry and may also provide environmental gains due to the financing of conservation units in the areas of influence of the enterprises. However, there is a need to improve the methodology used to estimate the EO, since a maximum limit is set, the environmental impacts caused by the projects are underestimated.

Classificação dos serviços ecossistêmicos prestados pelas áreas úmidas na zona estuarina do Rio Piancó-Piranhas-Açu (Nordeste, Brasil)

As áreas úmidas são ecossistemas importantes tanto para a sociedade como para a biodiversidade, apresentam-se em zonas de transição entre os ambientes terrestres e aquáticos, responsáveis por oferecer serviços para o bem estar humano e biológico, resultantes do seu capital natural. O presente trabalho teve como objetivo avaliar os serviços ecossistêmicos prestados pelas áreas úmidas no complexo estuarino do Rio Piancó-Piranhas-Açu (RN). Foi realizado o mapeamento e classificação das áreas úmidas, assim como a identificação dos serviços ecossistêmicos prestados na área de estudo. A partir desta perspectiva integrada da dinâmica entre o uso humano e seus reflexos nos processos ecológicos dos ecossistemas analisados (ex. manguezal, lagoas, lagunas, salinas solares, etc.), tem-se um melhor entendimento do desempenho destes processos, os quais propiciam a manutenção ou maior disponibilidade de serviços ecossistêmicos considerados chave para a gestão costeira.
 Palavras chaves: Capital Natural, Litoral Semiárido do Brasil, SIG, Classificação CICES.

Review on integrated production of the brine shrimp Artemia in solar salt ponds

AbstractThe brine shrimp Artemia is a highly required, convenient and cost‐effective live food used in fish and shellfish larviculture. Its cysts, originating from a limited number of inland salt lakes, are traded worldwide. Over the past decades, Artemia pond production in solar saltworks, integrated with salt production, has emerged as an alternative to cope with possible cyst shortages and high prices on the international market and as a tool to fulfill local cyst and Artemia biomass demands associated with local and regional aquaculture developments. This article reviews the principles of Artemia pond production and how it is practiced in terms of general management. It also describes the distinctive features that have evolved in various countries, due to geographical, environmental and socio‐economic characteristics and the local aquaculture context. It highlights the lessons that may be learnt from previous successes and failures for new areas where the technique may be introduced. The principles of Artemia pond production are also discussed in the light of global and local Artemia biodiversity, as its protection is key to support the sustainability of the aquaculture industry. This review pioneers in bringing this information, much of which was restricted to grey literature until now, under the attention of the international scientific audience. Future research and development should focus on continued proper management to secure cyst production and to maximize cyst quantities. Moreover, using the information provided by the Artemia genome will allow as well to strive for improved cyst quality, by producing strains with specific market characteristics.

Potable water by solar thermal distillation in solar salt works and performance enhancement by integrating with evacuated tubes

Solar salt farms are located in remote coastal regions where the ground water is saline. During the salt harvesting season, the salt workers face difficulties owing to shortage of potable water at-site. Nevertheless such locations are blessed with plenty of sunshine and in-situ desalination for potable water in solar distillation system or still, benefits the workers to a great extent. Since such solar stills are directly applied in field, the design and operation approach ought to be such, that water output is high and maintenance easy. In this work, we report analysis of stepped type basin still and enhancement of output by integrating with evacuated tube collectors (ETC). The average augmentation of productivity was 24% by the integration during the period of March to May 2018. The study of warm feed water charging time from ETC was an important aspect and it was found that highest production could be obtained by night-charging, due to low top glass temperature which led to increased condensation and more productivity. 8.1 L per day from 2 m2 basin area was the maximum productivity from ETC integrated unit. The novelty of the work involves incorporation of particular operational features like (a) single basin stepped tilted absorber with triangular exposure area, avoiding shadow effect; (b) distance between glass and water surface minimum for facile evaporation; (c) easy cleaning of the deposited salts by overflowing water from tilted surface; and (d) endurance of glass tubes of ETC in corrosive salty environment.

Broad Environmental Tolerance for a Salicola Host-Phage Pair Isolated from the Cargill Solar Saltworks, Newark, CA, USA.

Phages greatly influence the ecology and evolution of their bacterial hosts; however, compared to hosts, a relatively low number of phages, especially halophilic phages, have been studied. This study describes a comparative investigation of physicochemical tolerance between a strain of the halophilic bacterium, Salicola, isolated from the Cargill Saltworks (Newark, CA, USA) and its associated phage. The host grew in media between pH 6–8.5, had a salinity growth optimum of 20% total salts (ranging from 10%–30%) and an upper temperature growth limit of 48 °C. The host utilized 61 of 190 substrates tested using BIOLOG Phenotype MicroArrays. The CGφ29 phage, one of only four reported Salicola phages, is a DNA virus of the Siphoviridae family. Overall, the phage tolerated a broader range of environmental conditions than its host (salinity 0–30% total salts; pH 3–9; upper thermal limit 80 °C) and is the most thermotolerant halophilic phage ever reported. This study is the most comprehensive investigation to date of a Salicola host–phage pair and provides novel insights into extreme environmental tolerances among bacteriophages.

From Ecology to Biotechnology, Study of the Defense Strategies of Algae and Halophytes (from Trapani Saltworks, NW Sicily) with a Focus on Antioxidants and Antimicrobial Properties.

This study aimed at the characterization of the antioxidant power of polyphenol extracts (PE) obtained from the algae Cystoseira foeniculacea (CYS) (Phaeophyta) and from the halophyte Halocnemum strobilaceum (HAL), growing in the solar saltworks of western Sicily (Italy), and at the evaluation of their anti-microfouling properties, in order to correlate these activities to defense strategies in extreme environmental conditions. The antioxidant properties were assessed in the PE based on the total antioxidant activity test and the reducing power test; the anti-microfouling properties of the two PE were evaluated by measuring the growth inhibition of marine fish and shellfish pathogen bacteria as well as marine surface fouling bacteria and microalgae exposed to the fractions. Similar polyphenol content (CYS 5.88 ± 0.75 and HAL 6.03 ± 0.25 mg gallic acid equivalents (GAE) g−1 dried weight, DW) and similar reducing power percentage (93.91 ± 4.34 and 90.03 ± 6.19) were recorded for both species, even if they exhibited a different total antioxidant power (measured by the percentage of inhibition of the radical 2,2 diphenyl-1-picrylhydrazyl DPPH), with CYS (79.30) more active than HAL (59.90). Both PE showed anti-microfouling properties, being inhibitors of adhesion and growth of marine fish and shellfish pathogen bacteria (V. aestuarianus, V. carchariae, V. harveyi, P. elyakovii, H. aquamarina) and fouling bacteria (V. natriegens, V. proteolyticus, P. iirgensii, R. litoralis) with minimum inhibitory concentrations comparable to the commercial antifouling products used as a positive control (SEA-NINE™ 211N). Only CYS was a significant inhibitor of the microalgae strains tested, being able to reduce E. gayraliae and C. closterium growth (MIC 10 µg·mL−1) and the adhesion of all three strains tested (E. gayraliae, C. closterium and P. purpureum), suggesting its promise for use as an antifouling (AF) product.