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One of the biggest global challenges in the mining industry is managing the risks associated with contamination by potentially toxic elements (PTEs) resulting from their activity. The oxidation of sulfides is the main cause of polluted mine drainage through the leaching of PTEs from mine waste and mine galleries to the water systems. Mine drainage can be highly acidic and often has a high concentration of PTEs, particularly arsenic, one of the environment’s most toxic elements. PTEs endanger the ecosystem’s equilibrium and raise worries about human and animal health. Some species of algae which can be naturally present in mine drainage waters, such as Spirogyra sp. And Chlorella sp., have a high capacity for absorbing PTEs from wastewater and may thrive in harsh environments. As a result, algal-based systems in bioremediation were studied and carefully analyzed, since their capacity to remove heavy metals and hazardous contaminants from polluted mine water have already been shown in previous studies. Biofuels derived from microalgal biomasses are a viable alternative to fossil fuels that can lead to a circular bioeconomy. This study reviews and analyses Chlorophyta-based bioremediation systems with application to mine waters focusing on Spirogyra sp. and Chlorella sp., since they are naturally present in mine drainage and can serve as a study model to better understand their application in bioremediation.

The ecosystem services can be divided using two major classification systems, the Millennium Ecosystem Assessment (MEA) and the Common International Classification of Ecosystem Services (CICES). In the MEA system, the ecosystem services are divided into four major service clusters: supporting, provisioning, regulating, and cultural. On the other hand, the CICES system regards the “MEA supporting services” as organism natural function (and not an ecosystem service). Thus, this function is the basis for all the three CICES ecosystem services (provisioning, regulating, and cultural) provided by one organism. These ecosystem services can be analyzed for the type of habitat, fauna or flora. Seaweeds, or marine macroalgae, are one of the key organisms in estuarine and seawater habitats ecosystems, which currently is of extreme importance due to the climate changes and the blue–green economy. Seaweeds and humankind have been interlinked from the beginning, mainly as a food source, fibers, biochemicals, natural medicine, ornamental resources, art inspiration, and esthetic values in several coastal communities. Moreover, currently they are being studied as green carbon, carbon sequestration, and as a possible source for the biomedical and pharmaceutical areas. This review is a concise review of all ecological services provided by seaweeds and their impact in the human life and maintenance of the ecosystem status quo. The future of seaweeds use is also approached, regarding the promotion of seaweed ecological services and its dangers in the future.

Estuarine eutrophication due to the nutrient run-off from the agricultural fields encourages the establishment of several opportunistic seaweeds. These fast-growing seaweeds, considered an untapped resource, with a circular economy approach, can be employed as soil plant fertilizer. In agriculture, there is a global trend toward shifting from chemical-based conventional farming to sustainable agriculture. In this context, this study aimed to understand the biostimulant potential of the aqueous extracts from seaweeds harvested in Mondego estuary located on the Atlantic coast of Portugal, namely Ulva lactuca (Sea lettuce), Fucus ceranoides (Estuary Wrack) and Gracilaria gracilis (Slender Wart Weed), in kale (Brassica oleracea L.) seed germination and seedling development. The results showed that Gracilariagracilis extract enhanced kale seed germination, presenting a higher seedlings weight (0.076 ± 0.004 g) and length (15.48 ± 0.59 cm), when compared with seedlings obtained in distilled water used as a control (weight = 0.059 ± 0.002 g; length = 13.10 ± 0.54 cm). Fucus ceranoides showed the lowest influence on seedling development (weight = 0.062 ± 0.002 g; length = 12.97 ± 0.59 cm). However, these results demonstrated that seaweed aqueous extracts can indeed enhance seed germination and seedling development.

The high incidence of changes in the lipid profile in the world population is supported by the adoption of a lifestyle with numerous risk factors. Dyslipidemia, the main alteration in the lipid profile, is characterized by increased concentrations of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), triglycerides (TG), and decreased concentration of high-density lipoprotein cholesterol (HDL-C). These modifications in lipid metabolism are particularities of metabolic syndrome (MetS) and one of the main risk factors for the development of cardiovascular diseases (CVD), one of the main causes of death in the world. Macroalgae have a high percentage of dietary fiber, and a low percentage of lipids. Carrageenans, long-chain polysaccharides extracted from red macroalgae, are present in several foods, such as jelly. Chemically, they present several structures with different applications and purposes in the cosmetic, food, and pharmaceutical industries. The bioactive potential of carrageenans has demonstrated potential in the reduction of the levels of parameters of the lipid profile, being able to be an alternative in the reversion of MetS and, consequently, in the prevention and treatment of CVD. This review article aims to compile, evaluate, and reflect on the effect of carrageenans on lipid profile markers (TC, TG, HDL-C, LDL-C), relating them to MetS and CVD.

Because the world's population is increasing, science-based policies are needed to promote sustainable global development. It is important to maintain and restore the environment and help human society overcome the risks from industrialization and unsustainable exponential growth. In recent years, many studies have highlighted that macroalgae represent a key marine resource for ecological and sustainable living, thus helping to address today's global problems, such as water pollution, ocean acidification, and global warming. Macroalgae show the potential to provide innovative, ecofriendly, and nutritious food sources and natural compounds for various industries, such as biomedical, food, agricultural, and pharmaceutical industries. This review discusses how macroalgae can help us today and how they can promote a more sustainable way of life in the future. It also discusses the potential danger for ecosystems and the global population if these organisms are not part of the solution but part of the problem. Integr Environ Assess Manag 2022;18:1148-1161. © 2022 SETAC.

Recently, there has been increased interest in the development of novel antimicrobial compounds for utilization in a variety of sectors, including pharmaceutical, biomedical, textile, and food. The use, overuse, and misuse of synthetic compounds or derivatives have led to an increase of pathogenic microorganisms gaining resistance to the traditional antimicrobial therapies, which has led to an increased need for alternative therapeutic strategies. Seaweed are marine organisms that can be cultivated sustainably, and they are a source of polar molecules, such as pigments and phenolic compounds, which demonstrated antimicrobial potential. This review focuses on current knowledge about pigments and phenolic compounds isolated from seaweeds, their chemical characteristics, antimicrobial bioactivity, and corresponding mechanism of action.

With respect to the potential natural resources in the marine environment, marine macroalgae or seaweeds are recognized to have health impacts. Two marine algae that are found in the Red Sea

Polyphenols are compounds found in various plants and foods, known for their antioxidant and anti-inflammatory properties. Recently, researchers have been exploring the therapeutic potential of marine polyphenols and other minor nutrients that are found in algae, fish and crustaceans. These compounds have unique chemical structures and exhibit diverse biological properties, including anti-inflammatory, antioxidant, antimicrobial and antitumor action. Due to these properties, marine polyphenols are being investigated as possible therapeutic agents for the treatment of a wide variety of conditions, such as cardiovascular disease, diabetes, neurodegenerative diseases and cancer. This review focuses on the therapeutic potential of marine polyphenols and their applications in human health, and also, in marine phenolic classes, the extraction methods, purification techniques and future applications of marine phenolic compounds.

With the notable scarcity of Chondrus crispus on the Portuguese coast, and interest in exploiting compounds such as carrageenan, this study focuses on investigating different aquaculture methods and recording the yield of carrageenan from specimens grown by different methods. We compare the growth of Chondrus crispus in aquaculture using Free Floating, Cages, Attempted Fixation on Rock, and Fixed Line similar to Long Line. The best method was Free Floating where Nursery 0 had a 24-day Specific Growth Rate (SGR) of 2.08 ± 0.47%/day. The worst method in terms of growth was Nursery 2 (Attempted Fixation on Rock) where the SGR at 28 days was 0.33 ± 0.69%/day, and no fixation was observed. In terms of carrageenan extraction, all culture methods gave rise to biomass that had a lower extraction yield than wild specimens, at 50.95 ± 4.10%. However, the Free-Floating method from Nursery 1 showed an acceptable carrageenan content (31.43 ± 7.00%). Therefore, we demonstrate that the concept of C. crispus cultivation may be key to promoting the sustainability and stability of this species.

Algae (and their extracts) are increasingly important for pharmaceutical applications due to the diversity of useful compounds they contain. The genus Fucus contains one of the most studied species, Fucus vesiculosus. The species F. ceranoides differs from the others of the genus by presenting longitudinal air-vesicles and a capacity to survive at low salinities. It is an alga that inhabits the Mondego River estuary (Portugal), at the southern limit of its distribution, and can serve as a role model to understand the effect of a salt gradient on the production of bioactive compounds. We assessed the phenolic content and antioxidant activity of different F. ceranoides extracts (e.g. methanolic, aqueous and polysaccharide) prepared from samples harvested from two different zones to evaluate if the adaptation of F. ceranoides to different salinity levels influenced its chemical composition. The antioxidant activity of the extracts was determined using 1,2-diphenyl-picrylhydrazyl (DPPH) and 2.2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radicals. These assays demonstrated that the methanolic extract of lyophilized F. ceranoides that grew at low salinities was the most bioactive, i.e. DPPH (IC50=50.39 µg/mL) and ABTS (TEAC=2.42). The total phenolic content (Folin-Ciocalteu method) and the methanolic extract of the lyophilized F. ceranoides collected from a low salinity habitat exhibited the highest phenolic content (PGE=49.48 µg/mg of lyophilized extract) amongst those sampled. Thin layer chromatography (TLC) and Fourier transform infrared spectroscopy (FTIR) were used for the identification of compounds in the extracts. This characterization allowed confirmation that the various extracts contained almost the same compounds but with notable quantitative differences. Based on these results, we conclude that there were differences in the quantity of the compounds due to the effect of salinity. The drying methods used were also found to have influenced the quality of the extracted compounds.

World aquaculture is increasingly diversified and intensive, due to the use of new technologies, having grown a lot in recent decades and contributed significantly to improving food security and reducing poverty in the world, with fish farming being a promising activity for the production of protein with high nutritional value. The large aquaculture companies that recognize the potential of this important modality have invested in the study and production of various productive segments of the most diverse species of fish. This review article aims to provide information on the world panorama of marine fish farming, with the main systems and production stages of the most important organisms with commercial potential, aiming to achieve a highly sustainable production, with high nutritional content and benefits for human health. The production of live feed in the larval stage should be highlighted, in order to optimize survival and weight gain. In addition, trends in the cultivation of estuarine and saltwater fish will be detailed in this review, such as the use of biotechnology and technological innovations, cultivations integration, and biosecurity. Thus, innovative methods to optimize the farming system need to be more ecosustainable, reducing the negative impacts on the environmental level.

The accumulation of Marine Macroalgal Waste (MMW) - drifted marine macroalgae - is a growing phenomenon. The lack of appropriate management protocols for this residual biomass leaves it mostly unmanaged or disposed of in landfills. Such inappropriate solutions lead to negative environmental impacts, health concerns and coastal degradation, representing an opportunity to develop the bioeconomy. Although a relevant number of studies exists on the use of edible marine macroalgae for several purposes, there is generally a lack of information concerning MMW valorisation, at both local and global scales. This review thus explores the ecological and biotechnological potential for the establishment of a new approach for MMW valorisation based in the circular and blue economies. It is supported in literature on the use of residual biomass whenever possible and also includes studies with fresh biomass to extrapolate, considering known characteristics of MMW; consequently, a roadmap for its utilisation is provided. The review includes characteristics of various seaweeds, MMW accumulation worldwide and traditional uses, together with the development of alternative and integrated valorisation strategies. By analysing a large number of studies, it was possible to perceive a clear potential to explore MMW to obtain renewable fuels, especially biogas and bioethanol and for use in agricultural activities. Allied to this, the extraction of value-added compounds, such as lipids, pigments, phenolic compounds and specific polysaccharides is highlighted, aiming to contribute to the development of an economically feasible zero-waste biorefinery approach.

Seaweeds have been a food source since ancient times (600 BC) and are still widely used in Asia, mainly in traditional Chinese medicine and Japanese folk medicine. Nowadays, seaweed compounds and extracts have been gaining interest from the biomedical and pharmaceutical market sectors. Seaweeds have been referenced as feasible solutions in finding new potential compounds and therapies in prevention, control, and reduction of cancer development due to the multirole of some bioactive components (e.g, phenolic compounds and sulphated polysaccharides). Moreover, seaweeds are rich in important health-promoting molecules [such as poly and highly unsaturated fatty acids (PUFAs and HUFAs), essential amino acids, vitamins, and dietary fibers] and minerals (calcium, iron, iodine, magnesium, phosphorus, potassium, zinc, copper, manganese, selenium, and fluoride). In this review, the potential therapeutic effects of seaweed in the prevention and treatment of cancer are approached, as well as nutraceutical properties of seaweed to promote cell homeostasis.

In recent years, an increased interest in marine macroalgae bioactive compounds has been recorded due to their benefits to human health and welfare. Several of their bioactivities have been demonstrated, such as anti-inflammatory, antioxidant, anticarcinogenic, antibacterial and antiviral behavior. However, there still lacks a clear definition regarding how these compounds exert their bioactive properties. Of all the bioactive compounds derived from marine macroalgae, attention has been focused on phenolic compounds, specifically in phlorotannins, due to their potential for biomedical applications. Phlorotannins are a diverse and wide group of phenolic compounds, with several structural variations based on the monomer phloroglucinol. Among the diverse phlorotannin structures, the eckol-family of phlorotannins demonstrates remarkable bioactivity, notably their anti-tumoral properties. However, the molecular mechanisms by which this activity is achieved remain elusive and sparse. This review focuses on the described molecular mechanisms of anti-tumoral effects by the eckol family of compounds and the future prospects of these molecules for potential application in oncology therapies.

Seaweeds have a great variety of compounds with different properties and benefits to human health. Marine macroalgae provide a high nutritional value along with low caloric value, poor in fat, and with the presence of polysaccharides that behave as fibers with no calories. This is not widespread, but some macroalgae and by-products are used in various applications, inclusively in food products. Under the project MENU - Marine Macroalgae: Alternative recipes for a daily nutritional diet, six native seaweed species were collected in Praia da Tamargueira, Buarcos, Figueira da Foz, Portugal: Ulva spp. (green seaweed), Chondrus crispus, Gracilaria gracilis, Mastocarpus stellatus, Porphyra umbilicalis (red seaweeds) and Bifurcaria bifurcata (brown seaweed) to further biochemical characterization. Polysaccharides’ monomeric composition was determined after sulphuric acid hydrolysis, derivatization to alditol acetates, then analyzed by gas chromatography with flame ionization detector (GC-FID), whereas protein content was quantified following colorimetric Bradford method. Results showed red seaweeds presenting the highest polysaccharide profile followed by the green macroalgae and then the brown seaweed species. In the case of protein content, Porphyra umbilicalis was the seaweed with the highest content, followed by Ulva spp., Gracilaria gracilis, Chondrus crispus and Mastocarpus stellatus. The brown seaweed Bifurcaria bifurcata presented the lowest protein content.

Seaweeds are one of the most sustainable and feasible natural sources to the imminent food shortage, due to their nutritional profile. Seaweed aquaculture is an important tool for seaweed food safety and maintain the nutritional value. The specie Gracilaria gracilis (Rhodophyta) is an edible seaweed, which can contribute to a balanced diet. The objective of this work was to evaluate the nutritional profile of G. gracilis in semi-controlled aquaculture (SCA), located in the estuarine zone of the Mondego River (Figueira da Foz, Portugal) compared to specimens harvested in the natural environment (SW). G. gracilis that presented good growth rate in the aquaculture system (4.70%/day), and its biomass, analyzed by Weende method, showed that SCA had different nutritional profile than SW. A fresh weight of cultivated G. gracilis showed some differences in moisture (SCA = 85.49% ± 0.02; SW = 86.04% ± 0.01), ash (SCA = 3.96% ± 0.01; SW = 4,10% ± 0.01), fat (SCA = 0.01% ± 0.00; SW = 0.01% ± 0.00), fiber (SCA = 0.79% ± 0.01; SW = 0,68% ± 0.00), protein (SCA = 2.07% ± 0.01; SW = 2.54% ± 0.01) and carbohydrate (SCA = 7.69% ± 0.02; SW = 6.64% ± 0.01). These results support the importance of G. gracilis aquaculture cultivation, maintaining the seaweed nutritional quality, when compared to the wild specimens obtained from the sea. Thus, promoting an eco-sustainable way of cultivating seaweeds for nutritious food purposes and even promoting the global food safety.

Seaweeds have attracted high interest in recent years due to their chemical and bioactive properties to find new molecules with valuable applications for humankind. Phenolic compounds are the group of metabolites with the most structural variation and the highest content in seaweeds. The most researched seaweed polyphenol class is the phlorotannins, which are specifically synthesized by brown seaweeds, but there are other polyphenolic compounds, such as bromophenols, flavonoids, phenolic terpenoids, and mycosporine-like amino acids. The compounds already discovered and characterized demonstrate a full range of bioactivities and potential future applications in various industrial sectors. This review focuses on the extraction, purification, and future applications of seaweed phenolic compounds based on the bioactive properties described in the literature. It also intends to provide a comprehensive insight into the phenolic compounds in seaweed.

Seaweeds have been incorporated in the daily diet of several human cultures since ancient times, due to their nutritional characteristics and healthy properties. The brown seaweeds Undaria pinnatifida, Saccharina latissima, Sacchoriza polyschides, and Laminaria ochroleuca were collected in the Viana do Castelo (Portugal) bay to assess their proximate composition analysis. As a result, the algal biomass was dried, and its moisture and ash content were determined. The dried biomass was then analyzed for total nitrogen/total protein (using the Kjeldahl method), total fiber content (through fiber analyzer digestion), total lipids (in a Soxhlet apparatus), and fatty acid characterization (by gas chromatography-mass spectrometry). Apart from phosphorus, which was analyzed by spectrophotometry, the ashes were employed for mineral and trace element characterization via dry mineralization and quantified using flame atomic absorption spectrometry. Moreover, the total phenolic content was assessed spectrophotometrically by the Folin-Ciocalteu method in the algal aqueous extracts. Analyses showed that their protein concentrations ranged from 12 to 24% dry weight (DW), while lipid concentrations varied between 0.51% and 1.52% DW. Regarding the carbohydrate concentration in these seaweeds, a concentration between 48% and 60% DW was observed. The S. polyschides had the highest overall total phenolic content (6.19 × 10−3 g GAE/100 g of dried algae), while L. ochroleuca had the lowest amount (3.72 × 10−3 g GAE/100 g of dried algae). U. pinnatifida had the highest total fatty acid content (35.13 mg/g DW), whereas S. latissima presented the lowest value (22.59 mg/g DW). Significant concentrations of highly unsaturated fatty acids (HUFA) were observed in both seaweeds, with U. pinnatifida having the highest value (10.20 mg/g DW) and S. latissima the lowest content (4.81 mg/g DW). It is also highlighted that these seaweeds have a nutritional relevance as a source of essential nutrients, including nitrogen, potassium, sodium, calcium, magnesium, and iron.

Presently, there is a high demand for nutritionally enhanced foods, so it is a current challenge to look at new raw food sources that can supplement beneficially the human diet. The nutritional profile and key secondary metabolites of red seaweeds (Rhodophyta) are gaining interest because of this challenge. In this context, the possible use of the red seaweed Chondracanthus teedei var. lusitanicus (Gigartinales) as a novel nutraceutical source was investigated. As a result, we highlight the high mineral content of this seaweed, representing 29.35 g 100 g−1 of its dry weight (DW). Despite the low levels of calcium and phosphorus (0.26 and 0.20 g 100 g−1 DW, respectively), this seaweed is an interesting source of nitrogen and potassium (2.13 and 2.29 g−1 DW, accordingly). Furthermore, the high content of carbohydrates (56.03 g 100 g−1 DW), which acts as dietary fibers, confers a low caloric content of this raw food source. Thus, this study demonstrates that C. teedei var. lusitanicus is in fact an unexploited potential resource with the capability to provide key minerals to the human diet with promising nutraceutical properties.

Maceiras or fields of maceira constitute a form of agriculture unique in the world, and can even be said to be indigenous to Minho, north of Portugal. This form of agriculture, widely used on the coasts of these two countries, was invented; it is said, in the 18th century by the Benedictine monks of the abbey of Tibaes. The principal function of the boat was similar to that of an ox cart, plow or other agricultural equipment, but the boat also served to transport goods, foods, people and livestock within the Ria de Aveiro. One of the interesting and important features of the agriculture of the Channel Islands, and particularly of the agriculture of Jersey before 1900, was the use of seaweed as fertilizer. A habitual feature of the agricultural scene, seaweed was the cause of much litigation and legislation in Jersey, largely because of its supreme value when applied to the sandy soils that cover most of the island.

Seaweeds are a potential source of bioactive compounds that are useful for biotechnological applications and can be employed in different industrial areas in order to replace synthetic compounds with components of natural origin. Diverse studies demonstrate that there is a solid ground for the exploitation of seaweed bioactive compounds in order to prevent illness and to ensure a better and healthier lifestyle. Among the bioactive algal molecules, phenolic compounds are produced as secondary metabolites with beneficial effects on plants, and also on human beings and animals, due to their inherent bioactive properties, which exert antioxidant, antiviral, and antimicrobial activities. The use of phenolic compounds in pharmaceutical, nutraceutical, cosmetics, and food industries may provide outcomes that could enhance human health. Through the production of healthy foods and natural drugs, bioactive compounds from seaweeds can help with the treatment of human diseases. This review aims to highlight the importance of phenolic compounds from seaweeds, the scope of their production in nature and the impact that these compounds can have on human and animal health through nutraceutical and pharmaceutical products.

Seaweed-based cosmetics are being gradually used by consumers as a substitute of synthetic equivalent products. These seaweed-based products normally contain purified compounds or extracts with several compounds. Several seaweeds’ molecules already demonstrated a high potential as a cosmetic active ingredient (such as, mycosporine-like amino acids, fucoidan, pigments, phenolic compounds) or as a key element for the products consistency (agar, alginate, carrageenan). Moreover, seaweeds’ compounds present important qualities for cosmetic application, such as low cytotoxicity and low allergens content. However, seaweeds’ biochemical profile can be variable, and the extraction methods can cause the loss of some of the biomolecules. This review gives a general look at the seaweed cosmetics benefits and its current application in the cosmetic industry. Moreover, it focuses on the ecological and sustainable scope of seaweed exploitation to guarantee a safe source of ingredients for the cosmetic industry and consumers.