Brown Algae Research Articles

Flagellar proteomic analysis of the brown alga Mutimo cylindricus revealed a novel calcium-binding protein abundantly localized in the anterior flagellum

Mutimo cylindricus gametes have two flagella with different structures : an anterior and a posterior flagellum. Their flagellar waveforms are regulated by calcium ions through various mechanisms, however the factors involved in this regulation remain largely unknown To elucidate the molecular basis underlying the difference between the two flagella, we performed a flagellar proteomic analysis of male M. cylindricus gametes. We identified 848 proteins shared with Ectocarpus siliculosus, including 28 calcium-binding proteins. Among the EF-hand proteins, a 111 kDa protein showed predominant localization along the anterior flagellum. Immunogold localization suggested that this protein is associated with outer doublet microtubules. This is the first report to show heterogeneous localization of a calcium-binding protein between two flagellar axonemes and suggests that calcium-binding proteins are involved in the specific regulation of the anterior flagellum.

Brown algae of the White Sea as a promising source of fucoidan for increasing resistance in laying hens

The purpose of this study was to evaluate the effect of a feed additive from fucus algae on resistance indicators of laying hens in industrial poultry farming conditions. In the algae F. vesiculosus and A. Nodosum, it was revealed that the mass fraction of fucoidan in terms of a.d.w. is 3.92±0.12%.When assessing the effect of using a feed additive from fucus algae on resistance indicators of laying hens, it was revealed that it has an effect on white and red blood parameters, leukogram and phagocyte activity. In chickens of the experimental group, there was a tendency towards an increase in the number of erythrocytes, an increase in the color index, a tendency towards a decrease in the number of leukocytes relative to the increase in the control group, while the indicators were within the reference values, after 30 days of using the additive – in the experimental group the proportion of pseudoeosinovils increased by 50% and the proportion of lymphocytes decreased by 6% compared to the control group. After 60 days of using the supplement, this trend continues: the proportion of pseudoeosinophils increased by 22% and the proportion of lymphocytes decreased by 4% in the experimental group relative to the control group. In our opinion, this indicates a normalization of the ratio of leukocyte forms in the experimental group, and, consequently, the immune status. In addition, in the experimental group relative to the control group, there was a significant decrease in the number of eosinophils by 67%, which may indicate a lower allergic reaction of the body’s immune system. Indicators of blood phagocytosis significantly changed after 60 days of use: in the experimental group, phagocytic activity increased by 23%, which indicates a higher ability of leukocytes in the experimental group to absorb foreign bacteria, and, consequently, stronger cellular immunity compared to the control group. Thus, the use of a feed additive from fucus algae for laying hens containing fucoidan in an amount of 3.92±0.12% helps to normalize the ratio of leukocyte forms and increase blood phagocytosis rates, which significantly increases resistance in laying hens.

Optimization of novel sustainable Dictyota mertensii alginate films with beeswax using a simplex centroid mixture design

The environmental risks of synthetic polymers drive the need for innovative and sustainable film and packaging solutions. This study optimized the formulation of films composed of alginate derived from the brown seaweed Dictyota mertensii (ADM), glycerol, beeswax, and tween 80, aiming to improve their properties. A simplex-centroid blend design was employed to develop and optimize the composite films. The films were characterized based on their morphological properties, moisture content (MC), contact angle (CA), solubility (S), water vapor permeability (WVP), color parameters (L∗, a∗, and b∗), opacity, tensile strength (TS), elongation at break (EB), and elastic modulus (E). Contour surfaces were plotted from the studied variables, fourth-order polynomial models were predicted, the influence of the blend components was analyzed, and the response variables were subjected to analysis of variance (ANOVA) and the F test with 95% confidence. The predicted conditions were experimentally validated. MC, WVP, solubility, opacity, a∗, and b∗ were minimized, whereas CA, L∗, TS, EB, and E were maximized, resulting in MC = 6.85%, WVP = 16.37 g mm/h.kPa.m2, S = 28.87%, CA = 83.86°, Opacity = 5.60 AU.nm.mm−1, L∗ = 70.31, a∗ = 4.79, b∗ = 21.00, TS = 11.76 MPa, EB = 12.70%, and E = 96.47 MPa. The overall desirability index was 0.70, resulting in an optimal biopolymer matrix of 75.00% ADM, 5.00% glycerol, 7.50% beeswax, and 12.50% Tween 80. The results highlight the potential of alginate films made from the brown seaweed Dictyota mertensii and the sustainable use of natural marine resources.

Multiple introduction events expand the range of the invasive brown alga Rugulopteryx okamurae to northern Spain

The brown alga Rugulopteryx okamurae is one of the most recent and aggressive marine invaders known, with a non-native range that spans from the western Mediterranean to the southern Iberian Peninsula, and the European Macaronesian archipelagos. Here, we provide the first record of its presence at three disjunct areas from northern Spain, supported by morphological and molecular evidence. Rugulopteryx okamurae was discovered in the port of Bilbao in the northeastern Atlantic of Spain, more than 1200 km away from the nearest invaded location previously known. It was also found at two separate areas in northwestern Spain: San Amaro, a small inlet at the entrance of the port of A Coruña, and Monteferro-Playa América, a site close to the port of Vigo. In two areas, R. okamurae was found to cover up to 100 % of the bottom, suggesting that it may behave as an aggressive invader in northern Spain. Our findings confirm the propensity of R. okamurae for long-distance dispersal and reveal that this invader is expanding its range northwards along the European Atlantic coast.

A transcriptomic hourglass in brown algae.

Complex multicellularity has emerged independently across a few eukaryotic lineages and is often associated with the rise of elaborate, tightly coordinated developmental processes1,2. How multicellularity and development are interconnected in evolution is a major question in biology. The hourglass model of embryonic evolution depicts how developmental processes are conserved during evolution, and predicts morphological and molecular divergence in early and late embryogenesis, bridged by a conserved mid-embryonic (phylotypic) period linked to the formation of the basic body plan3,4. Initially found in animal embryos5-8, molecular hourglass patterns have recently been proposed for land plants and fungi9,10. However, whether the hourglass pattern is an intrinsic feature of all complex multicellular eukaryotes remains unknown. Here we tested the presence of a molecular hourglass in the brown algae, a eukaryotic lineage that has evolved multicellularity independently from animals, fungi and plants1,11,12. By exploring transcriptome evolution patterns of brown algae with distinct morphological complexities, we uncovered an hourglass pattern during embryogenesis in morphologically complex species. Filamentous algae without canonical embryogenesis display transcriptome conservation in multicellular stages of the life cycle, whereas unicellular stages are more rapidly evolving. Our findings suggest that transcriptome conservation in brown algae is associated with cell differentiation stages, but is not necessarily linked to embryogenesis. Together with previous work in animals, plants and fungi, we provide further evidence for the generality of a developmental hourglass pattern across complex multicellular eukaryotes.

Assessing climatic conditions and biotic interactions shaping the success of Cystoseira foeniculacea early-life stages.

Early-life stages of canopy-forming macroalgae are critical for the maintenance of natural populations and the success of restoration actions. Unfortunately, the abiotic conditions and biotic interactions shaping the success of these stages have received less attention than the interactions shaping the success of adults. Here, we combined field and mesocosm experiments to explore the effects of temperature, herbivory, and canopy presence on the development of early-life stages of the brown seaweed Cystoseira foeniculacea. We assessed these effects by examining changes in recruit density and size. After recruiting zygotes under laboratory conditions, we conducted one laboratory and three field experiments. In the first field experiment, the density of recruits decreased over time in all rockpools and was negatively affected by rising temperatures and turf cover. Additionally, a marine heatwave (MHW; 11 days >25°C) was recorded in the donor pools, producing strong decay in the density of transplanted recruits and a significant reduction of the mature canopy. The second field experiment tested the survival of recruits based on their positioning within the canopy. We observed a higher density of recruits when placed at the edge or outside the canopy compared to recruits placed under the canopy. In the third field experiment, an herbivory-exclusion experiment, we show how density of recruits decreased in less than 48 h in noncaged treatments. In the laboratory, we conducted a thermotolerance experiment under controlled conditions, exposing the recruits to 19, 22, 25, 28, and 31°C for 7 weeks to assess thermal impacts on their survival and growth. Temperatures above the 25°C threshold reduced the density and size of the recruits. This study sheds light on the performance of the early-life stages of a Cystoseira spp. in Macaronesia, showing a low survival ratio against the current pressures even in the context of the potential refuge provided by the intertidal rockpools.

Formulating Brown Algae Derived Phloroglucinol-Based Epoxy Resin for High Performance Applications

Formulating Brown Algae Derived Phloroglucinol-Based Epoxy Resin for High Performance Applications

A cry for kelp: Evidence for polyphenolic inhibition of Oxford Nanopore sequencing of brown algae.

Genomic resources have yielded unprecedented insights into ecological and evolutionary processes, not to mention their importance in economic and conservation management of specific organisms. However, the field of macroalgal genomics is hampered by difficulties in the isolation of suitable DNA. Even when DNA that appears high quality by standard metrics has been isolated, such samples may not perform well during the sequencing process. We here have compared Oxford Nanopore long-read sequencing results for three species of macroalgae to those of nonmacroalgal species and determined that when using macroalgal samples, sequencing activity declined rapidly, resulting in reduced sequencing yield. Chemical analysis of macroalgal DNA that would be considered suitable for sequencing revealed that DNA derived from dried macroalgae was enriched for polyphenol-DNA adducts (DNA with large polyphenols chemically attached to it), which may have led to sequencing inhibition. Of note, we observed the strongest evidence of sequencing inhibition and reduced sequence output when using samples dried using silica gel-suggesting that such storage approaches may not be appropriate for samples destined for Oxford Nanopore sequencing. Our findings have wide-ranging implications for the generation of genomic resources from macroalgae and suggest a need to develop new storage methods that are more amenable to Oxford Nanopore sequencing or to use fresh flash-frozen tissue wherever possible for genome sequencing.

Exploration of an efficient and universal extraction strategy for fucoidan with glycolipid-lowering activity from typical brown algae: The importance of ball milling combined with acid treatment

Fucoidan possesses a variety of biological activities beneficial for human wellness. It is a good candidate for ameliorating obesity and diabetes. However, high-purity fucoidan products are limited due to the co-extraction of impurities i.e. alginate, protein and small molecular substances. In this study, the optimal preparation strategy for high-purity fucoidan from a template brown alga (Saccharina japonica) was screened out by the exploration of key and auxiliary steps. The key step was confirmed as moderate-temperature acid extraction and the auxiliary steps were fixed on ethanol refluxing and ball milling pretreatment. The fucose content of S. japonica fucoidan increased by 7.15 times and the sulfate group content increased by 4.87 times compared with those of fucoidans prepared by classic high-temperature acid extraction. Ball milling-assisted moderate-temperature acid extraction performed great effectiveness and universality in the extraction of high-purity fucoidans derived from four brown algae including S. japonica, Undaria pinnatifida, Sargassum fusiforme, and Fucus vesiculosus. Glycolipid-lowering activities of four fucoidans were confirmed by their interactions with intestinal bile acid, cholesterol micellar, glucose and probiotics including butyrate-producing bacteria, Bacteroides, Bifidobacterium, and Lactobacillus. Our study provided an efficient and universal extraction process for high-purity fucoidan with glycolipid-lowering activity from typical brown algae.

Metabolite Profiling of Macroalgae: Biosynthesis and Beneficial Biological Properties of Active Compounds.

Macroalgae are known as abundant sources of phytochemicals, which offer a plethora of beneficial biological properties. Besides being the most notable classes of compounds found in macroalgae, phlorotannins, bromophenols, and terpenoids comprise some of the most relevant for their biological properties. Phlorotannins, mainly prevalent in brown algae and structurally characterized as complex polyphenolic compounds derived from phloroglucinol units, possess robust antioxidant, anti-inflammatory, antitumor, and cytotoxic activities, modulated by factors such as the degree of polymerization and environmental conditions. Bromophenols, halogenated compounds found in algae and other marine organisms, exhibit significant antioxidant and antiviral properties. Their diverse structures and bromination patterns contribute to their potential as therapeutic and chemical defense agents. Pigments (chemically described as primary terpenoids) play a critical role in light absorption and energy transfer in macroalgae and are divided into three main groups: (i) carotenoids, which are primarily found in brown algae and provide photoprotective and antioxidant benefits; (ii) chlorophylls, known for facilitating the conversion of light into biological energy; and (iii) phycobilins, which are mostly found in red algae and play important roles in light absorption and energy transfer, besides providing remarkable health benefits. Finally, secondary terpenoids, which are particularly abundant in red algae (e.g., the Rhodomelaceae family) are central to cellular interactions and exhibit significant antioxidant, antimicrobial, antidiabetic, and anti-inflammatory properties. This study represents a detailed analysis of the biosynthesis, structural diversity, and biological activities of these macroalgae metabolites, emphasizing their potential biological properties.

4-Hydroxydictyolactone alleviates cerebral ischemia injury by regulating neuroinflammation and autophagy via AMPK signaling pathway

BackgroundCerebral ischemia (CI), a cerebrovascular disorder, is a major contributor to disability and mortality. Marine-derived compounds are an important source of new neuroprotective drug candidates. Xenicane-type diterpenes from brown algae of the genus Dictyota have exhibited potential neuroprotective effects against CI injury, attributed to their antioxidant properties. However, whether there are other underlying neuroprotective mechanisms of xenicane diterpenes against CI is still ambiguous. PurposeThis study aims to elucidate the neuroprotective efficacy and mechanism of 4-hydroxydictyolactone (HDTL) in the treatment of CI. MethodsThe LPS-induced BV2 cell model was used for anti-neuroinflammatory activity assay. Tandem Mass Tag (TMT)-based quantitative proteomics was employed to identify underlying mechanisms. The OGD/R-induced SH-SY5Y cell model and a MCAO mice model were used to assess the neuroprotective effect of HDTL against CI in vitro and in vivo. ResultsHDTL reduced inflammation in LPS-stimulated BV2 cells by inhibiting the IKK/IκB/NF-κB pathway and by enhancing AMPK phosphorylation. Additionally, in SH-SY5Y cells treated with OGD/R, HDTL facilitated autophagy and reduced apoptosis. The neuroprotective properties of HDTL were abrogated in AMPK- silenced SH-SY5Y cells. In MCAO mice, HDTL ameliorated CI injury as evidenced by decreases in neurological deficit scores and cerebral infarction. HDTL also promoted autophagy and reduced apoptosis in vivo through both the AMPK/mTOR and IKK/IκB/NF-κB pathways. ConclusionHDTL exhibits neuroprotective effects through regulating the AMPK/mTOR and IKK/IκB/NF-κB pathways. These findings suggest that HDTL is a promising therapeutic candidate for CI treatment.

Phlorotannins extracted from Sargassum ilicifolium as a way to control spoilage molds and extend the shelf life of Agaricus bisporus mushrooms

Phlorotannins (PTs) are compounds with notable bioactive characteristics obtained from brown algae. In the present study, PTs from the Sargassum ilicifolium seaweed were extracted, characterized, and evaluated for their anti-polyphenol oxidase (PPO) enzyme activity and in vitro antifungal activity against spoilage molds (Aspergillus flavus and Penicillium expansum) of button mushrooms. Then, PTs were used as a coating in combination with alginate (AL) to improve the shelf life of Agaricus bisporus mushrooms under storage conditions. HPLC analysis identified phloroglucinol as the predominant component in the PT extract (18.1 %), which demonstrated an 86 ± 1.02 % radical scavenging activity in the DPPH test. The PPO enzyme activity significantly decreased from 320.34 ± 2.1 units to 34.4 ± 1.4 units in the presence of 1.5 mL of PT extract. The PT extract's antifungal properties were observed through well diffusion assays, mycelial growth inhibition, and scanning electron microscopy on treated spoilage mold colonies. Better preservation of the physicochemical properties of mushrooms coated with AL + PT was confirmed through various tests, including assessments of weight loss, browning, malondialdehyde levels, total phenol content, and vitamin C content. Additionally, sensorial tests and evaluations of visual and microstructure changes during storage at 4 °C confirmed the enhanced preservation after treatment. Findings indicated that in addition to the antifungal properties of S. ilicifolium-derived PT, which can act as a natural antifungal, this substance, when used in combination with AL coating, can increase the shelf life of A. bisporus mushrooms 12 d of storage at 4 °C.

Investigating the Sway of Marine Brown Seaweed Gel as Natural Polymer in Properties of Concrete

In the present study, the effects of the fresh properties as slump, consistency and setting time and hardened concrete's characteristics such as compressive, split tensile and flexural strength for various ages, the brown seaweed (Sargassum wightii) gel was added to cement throughout differing proportions (1, 2, 3, 4 and 5%) by the mass of concrete. Durability and thermal tests such as water absorption, sorptivity, RCPT, acid attack and thermal conductivity also determined at various ages. Micro structural properties of seaweed gel were found out by SEM, FTIR and XRD analysis. Test results show that seaweed gel act as retarding admixture in cement up to 5% of addition. For instance, 5% alginate collections as a percentage of concrete mass showed a comparable compressive strength of about 42MPa. The use of seaweed gel improved the thermal characteristics of concrete by reducing its thermal conductivity roughly 50% for a 5% addition. The seaweed gels up to 5% addition in concrete will significantly improve the fresh-state properties of concrete without affecting its hardened properties. The future is completely dependent on eco-friendly materials; hence the use of natural organic additives to improve the strength and durability of cement concrete would be the better option for sustainability.

Seaweed-derived etherified carboxymethyl cellulose for sustainable tissue engineering

Biodegradability, biocompatibility, abundant supply from renewable sources, and affordability are the outstanding properties of cellulose that have prompted substantial studies into its potential in biomedical applications. Beyond terrestrial sources of cellulose, seaweeds have attracted much attention as a potential source of cellulose because they are widely available. Cellulose and its byproducts may be extracted from various macroalgae species, including red, green, and brown algae. The extracted cellulose's qualities vary depending on the algae species, age, and extraction process utilized. Cellulose's characteristics are enhanced through chemical modifications, specifically etherification and esterification, which substitute functional groups for hydroxyl groups, yielding a range of products, including cellulose acetate (CA), cellulose nitrate, cellulose sulfate, methylcellulose, and carboxymethyl cellulose (CMC). The ability to modify CMC characteristics for particular applications is explored through techniques including grafting processes mixing, and cross-linking with other polymers. Moreover, tissue engineering is given significant consideration in the growing use of CMC and its altered forms in biological applications. These alterations allow for the production of scaffolds that promote tissue regeneration and cell proliferation, enabling CMC-based scaffolds for various tissue engineering uses. This review provides a comprehensive overview of CMC's properties, modifications, and potential in tissue engineering.

Secular change in seaweed species composition and coverage of Sargassaceae on the artificial reef in Wakasa Bay, Japan.

The threat of declining seaweed beds has been a concern around the world. Seagrass and seaweed (brown algae) beds are essential habitats supporting fisheries. However, approximately 22% of these habitats have been lost in Japan due to increased coastal landfill sites and ports. This study aims to rehabilitate the depletion of these habitats by constructing an artificial reef in Wakasa Bay, Japan, and monitoring Sargassaceae succession in the second and fourth years after the construction was completed. In this study, we set up four sites on the artificial reef. Then we identified the seaweed species composition and coverage of the Sargassaceae using underwater visual observation by scuba divers. The seaweed coverage was already over approximately 80% in the second year after construction. The Sargassum horneri and S. confusum dominated during the first and second sampling in the second year after construction, and Myagropsis myagroides and S. patens during the third and fourth sampling in the fourth year after construction. Thus, the recovery of species composition takes longer than that of coverage. Therefore, observing species composition recovery is essential when constructing the artificial reef.

Seven undescribed meroterpenoids from Sargassum siliquastrum and their inhibitory activity against amyloid β aggregation.

The inhibition of amyloid β (Aβ) aggregation and degradation of Aβ aggregates are promising approaches for treating and preventing Alzheimer's disease. In our search for Aβ42 aggregation inhibitors, we isolated seven undescribed meroterpenoids, sargasilides A (1)‒G (7), from brown alga (Sargassum siliquastrum) collected at Noto Peninsula in Japan. We structurally elucidated the isolated meroterpenoids using spectroscopic data and evaluated their activities using Thioflavin T assay and transmission electron microscopy. Among the seven compounds isolated, sargasilide B had the strongest inhibitory activity. From the comparison of structure and activity, the geometric isomerism of olefins and length of isoprene side chains are important for the activity of meroterpenoids isolated from brown alga.

Investigating the Inhibitory Effect of Sargassum natans and Sargassum fluitans Extracts on Iron Corrosion in 1.00 mol L−1 HCl Solution

This study deals with the efficacy of extracts of Sargassum natans and Sargassum fluitans, an invasive brown algae present in Guadeloupe, as novel and environmentally friendly corrosion inhibitors for iron in 1 mol L−1 hydrochloric acid solutions. Six different Sargassum extracts (SE) were obtained using Soxhlet extraction with ethyl acetate, acetone, and ethanol, respectively, as solvents; cold successive maceration with chloroform and methanol, respectively; and microwave-assisted extraction with water. Subsequent electrochemical analysis showed that extracts from ethanol and ethyl acetate exhibited remarkable inhibition efficiencies of, respectively, 72.6% and 70.2%, but the better one was the extract of the cold maceration from chloroform with an inhibition efficiency of 92.0%. These findings allow us to focus on the chloroform extract (SEd) in order to see the change happening during the corrosion process via SEM and EDX analyses. Also, NMR analysis was conducted to identify the main chemicals responsible for the anticorrosion effect. The successful demonstration of the corrosion inhibitor effectiveness of extracts of Sargassum natans and fluitans suggests a potentially valuable use for this invasive biomass. These encouraging results warrant further investigation to identify and elucidate the active inhibitors in these extracts to deepen our understanding of their mechanisms for corrosion prevention and potentially expand their utility as an environmentally conscious approach to corrosion control.

Influence of brown algae filler and process parameters on the surface roughness and MRR of jute fiber polymeric composite machined by abrasive water jet

Traditional manufacturing of polymeric composite leads to delamination. Implementing abrasive water jet machining (AWJM) presents a sustainable solution for shaping the polymeric composites, thereby eliminating the need to dispose of chemically contaminated waste. Brown microalgae, commonly found in aquatic environments, serve as viable additives for enhancing the properties of polymeric composites. This study entails the polymeric composite reinforced with jute fiber fabricated by modulating the weight percentages of brown algae powder by 0, 3, and 6 wt.% utilizing the hand layup procedure. The composites were formed and subsequently subjected to drilling by AWJ machining filled with brown algae. The experimental investigation was done to analyze the effect of AWJ parameters: water jet pressure (WJP), traverse speed (TS), and stand-off distance (SoD)—on the material removal rate (MRR) and average surface roughness ( Ra). Orthogonal Array L27 experimental results revealed that polymeric composite reinforced with jute fiber containing 3 wt.% of brown algae exhibited the highest MRR, with an increase of up to 12% compared to other samples. Additionally, these composites demonstrated a significant reduction in surface roughness, reaching up to 8% when compared to alternative samples. Utilizing the Taguchi-based ANOVA method facilitated a systematic exploration and identification of influential factors impacting both MRR and Ra in AWJ machining. Notably, the WJP and SoD emerged as key factors significantly influencing both MRR and Ra.

Chemical synthesis of a trisaccharide fragment of a fucosylated glucuronomannan isolated from brown algae

Fucose is abundant in marine organisms, primarily as fucoidan and fucosylated chondroitin sulfate. Our previous study characterized a sulfated and fucosylated glucuronomannan (SFGM) isolated from marine brown algae, exhibiting notable antiviral activity and potential for drug development. Herein, a trisaccharide fragment of this SFGM in the form of [α-L-Fuc(2, 4-diS)]-(1→3)-α-D-Man-(1→4)-α-D-GlcA-OMP was synthesized for the first time. Stereoselective formation of the α-1,2-cis-fucosidic bond was achieved by leveraging solvent effects. The sulfated trisaccharide as the final product, featuring a 2,4-diS-fucose unit and the p-methoxyphenyl group as a pendant at the anomeric position, was successfully accomplished. The synthetic strategy developed in this study offers a foundation for the pharmaceutical development of these SFGM oligosaccharides.

Understanding the invasion of the macroalga Rugulopteryx okamurae (Ochrophyta) in the northern Alboran Sea through the use of biogeographic models

Rugulopteryx okamurae is a brown alga native to the northwestern Pacific and invasive elsewhere. It was first sighted in the southern Strait of Gibraltar in 2015, expanded to the northern Strait of Gibraltar in 2016, and had covered most of the northern Alboran Sea by 2021. Understanding the factors that may explain its different phases of colonisation is crucial for developing mitigation and control measures. We modelled the yearly distribution of R. okamurae in the northern Alboran Sea from 2016 to 2021 using the favourability function, which produces commensurable biogeographic models despite variations in species prevalence across years. This function also allows the use of fuzzy logic operations to combine previous environmental models based on different explanatory factors, namely biotope, biocoenosis, coastal influence, accessibility through dispersion, and oceanographic characteristics. Significant environmental models were assembled, and their fuzzy intersection and union applied. This resulted in two final biogeographic models for each year, which were used to predict the distribution of the species in following years. The biogeographic models exhibited a high predictive capacity, as most years accurately predicted colonisation in the following year or even multiple years ahead. Accessibility through dispersion and oceanographic characteristics were critical during the initial years of establishment, while complete establishment depended on all five factors together. Expansion to the whole northern Alboran coast was explained by favourable conditions for any of the explanatory factors, while all factors except coastal influence explained the saturation of the invasion. We conclude that the biogeographic models prove valuable in understanding the factors that contributed to the spread of R. okamurae in the northern Alboran Sea. This approach could help prevent further colonisation and mitigate the ecosystem and commercial consequences of R. okamurae's invasion.