Balanus Improvisus Research Articles

The bay barnacle Amphibalanus improvisus (Darwin, 1854) in the Pleistocene of Europe? A review of Pleistocene Balanidae of northern Central Europe

ABSTRACTThe bay barnacle Amphibalanus improvisus (Darwin, 1854) has been found in Northern Germany in brackish marine sediments of the Holsteinian interglacial. Whereas the cause of the contemporary distribution of this species is anthropogenic and there is evidence that it has resulted mainly from shipping, the fossil findings demonstrate that A. improvisus had also already reached Europe naturally during the Pleistocene in Europe, probably via the Gulf Stream system of the Atlantic. Today, A. improvisus is considered one of the most successful aquatic invasive species worldwide and it is characterized by a high environmental tolerance. The ingression of the Holsteinian Sea, during the Pleistocene, took place during the climate optimum from the North Sea into the ‘Elbe Estuary’ through the Hamburg region and far to the south‐east into Brandenburg. It has been possible to reconstruct the palaeo‐ecological conditions based in particular on molluscs. Accordingly, environmental conditions ranged from normal marine in the north, via brackish in the transitional area to limnic–fluviatile in the Berlin region. The morphological features of the bay barnacles and their ecological parameters are described here in detail. In addition, we provide a general review of the known Pleistocene Balanidae in northern central Europe.

Detailed integrative taxonomic analysis reveals large-scale species misidentification of barnacles based on DNA barcoding data

Abstract Morphological species identification is the traditional way to identify species. More recently, biodiversity studies have depended on DNA barcoding for species identification. Mismatches between morphological and genetic species identification caused by voucher specimen misidentifications lead to ambiguous species identification. We used barnacles of the genera Amphibalanus and Balanus to investigate this issue. The purpose of this study was to assess the accuracy of the Barcoding of Life database and determine the true species affinity of three inconsistent barnacle barcode index numbers using an integrative taxonomic approach. To this end, we re-identified barcoded voucher specimens, or we identified specimens based on a dichotomous key that we barcoded subsequently. We found that 75% of Barcoding of Life clades representing genetic species showed inconsistent species assignments. One clade (BOLD: AAG0069), containing mostly unidentified Balanus sp. individuals, was morphologically and genetically Balanus balanus (Linneaus, 1758); a second clade (BOLD: AAB1410), containing specimens mostly identified as B. balanus, turned out to be morphologically and genetically Balanus crenatus Bruguière, 1789; and a third clade (BOLD: AAE2482), containing different species of Amphibalanus, was Amphibalanus improvisus (Darwin, 1854). This study showed that morphological species identification and taxonomic expertise can resolve the widespread misidentification in barcoding data. To prevent this problem in the future, morphological taxonomy and molecular species identification need to interact more closely.

Juvenile Striped Bass consume diverse prey in Chesapeake Bay tributaries

AbstractObjectiveAnadromous Striped Bass Morone saxatilis are dominant predators in estuaries and coastal areas along the U.S. Atlantic coast, with the potential to exert top‐down control on prey populations. Although Striped Bass diets have been studied previously, spatiotemporal patterns of diet across ontogeny remain poorly understood, especially for young fish in shallow nursery habitats.MethodsWe collected and examined gut contents from adult, juvenile, and young‐of‐year (age‐0) Striped Bass from nine rivers across the Maryland and Virginia portions of Chesapeake Bay during summer and fall 2018. We compared the use of traditional morphological inspection and new amplicon‐based next‐generation sequencing methods for identifying gut contents.ResultStriped Bass in shallow tributary habitats of Chesapeake Bay had diverse diets that varied strongly with ontogeny and salinity zone. In particular, the diet of age‐0 Striped Bass varied greatly from those of juveniles and adults when age‐0 fish foraged in freshwater habitats. Although our results on prey consumed aligned with previous surveys, we identified additional taxa as important prey for these young fish, including dipteran insects, Banded Killifish Fundulus diaphanus, Inland Silverside Menidia beryllina, bay barnacle Amphibalanus improvisus, and grass shrimp Palaemon spp. Comparison of methodologies indicated that 40% of prey by weight could not be identified with morphological analysis, while 76% of mitochondrial cytochrome oxidase I sequences could be assigned binomial names, allowing for high‐resolution taxonomic comparisons.ConclusionThis study adds to the growing body of evidence that amplicon‐based next‐generation sequencing methods are far superior to traditional morphological analyses of gut contents for fine‐scale taxonomic resolution of prey.

Bryozoans in fouling communities on artificial substrates in Kazachya bay of the Black Sea

Study of the formation of fouling communities on artificial substrates is actual due to the development of mariculture in the Black Sea. Some representatives of macrofoulers are able to influence the process of colonization and development of cultivated organisms. Purpose of work. The main tasks of the study are the revealing the peculiarities of the formation of the fouling community on the experimental plates of the various materials in the environment of the Kazachya bay in the Black Sea and the role of bryozoans in the fouling community. Materials and methods. The experimental plates which were made from the different materials (plastic, aluminum, rubber, galvanized iron) were installed in September 2017 at a depth of 5 m in Kazachya bay (Black Sea). The plates were lifted every month during the year, a total of 480 plates were examined. Results. The peculiarities of the formation of the fouling community on the experimental plates of different materials in the Kazachya bay (Black Sea) were studied. Totally, 22 species were found in the macrofouling community formed on the experimental plates in the Kazachya bay during the year, comprising the following 8 taxa: hydroid polyps - 1, barnacles - 1, sea anemones - 1, bryozoans - 4, polychaetes - 4, bivalve mollusks - 1, tunicates - 2, macrophytes - 8. During the year, the succession of the fouling community of the experimental plates developed through the stage of dominance of microorganisms - barnacle Amphibalanus improvisus , and then - bryozoan Cryptosula pallasiana. Conclusion: the bryozoan Cryptosula pallasiana is the dominant species in the fouling community at four to twelve months old at a depth of five meters.

Evaluation of natural resveratrol multimers as marine antifoulants

In the current study we investigate the antifouling potential of three polyphenolic resveratrol multimers (–)-hopeaphenol, vaticanol B and vatalbinoside A, isolated from two species of Anisoptera found in the Papua New Guinean rainforest. The compounds were evaluated against the growth and settlement of eight marine microfoulers and against the settlement and metamorphosis of Amphibalanus improvisus barnacle cyprids. The two isomeric compounds (–)-hopeaphenol and vaticanol B displayed a high inhibitory potential against the cyprid larvae metamorphosis at 2.8 and 1.1 μM. (–)-Hopeaphenol was also shown to be a strong inhibitor of both microalgal and bacterial adhesion at submicromolar concentrations with low toxicity. Resveratrol displayed a lower antifouling activity compared to the multimers and had higher off target toxicity against MCR-5 fibroblasts. This study illustrates the potential of natural products as a valuable source for the discovery of novel antifouling leads with low toxicity.

Synopsis of exotic aquatic species present in the amazon continental shelf and adjacent areas

This study presents updated information on six exotic aquatic species (five crustaceans and one fish): Macrobrachium rosenbergii, Penaeus monodon, Charybdis hellerii, Balanus trigonus, Amphibalanus improvisus, and Pterois volitans. The research is based on bibliographic information available in scientific articles published by the Research Group Fishing and Evaluation of Tropical Fishery Resources and Biological and Photographic Records obtained from research projects conducted by CEPNOR/ICMBio. Currently, M. rosenbergii shrimp is classified as an invasive species, P. monodon is classified as a detected species, and C. hellerii is currently classified as an established species, but there are strong indications that it should be reclassified as invasive. The barnacles A. improvisus and B. trigonus have been classified as invasive, and lionfish P. volitans strongly exhibits advanced invasion process owing to its high frequency of capture in commercial fisheries.

Структура зооценозов обрастаний искусственных рифов в Северном Каспии

The study of artificial substrates fouling in the Caspian Sea is carried out by many scientists. The initiators of installing the artificial reefs in recent years have been the oil companies operating in the Caspian Sea, while the main goal was to improve the quality of the marine environment by increasing the self-cleaning ability of the marine ecosystem due to the development of filter organisms forming dense clusters on the surfaces of artificial substrates. There are presented the results of studies of the qualitative and quantitative composition of zooperiphyton of artificial reefs installed in the northern part of the Caspian Sea at the depths of 4-10 m. Samples were taken from the concrete artificial substrates. The studies were carried out by the conventional research methods. As a result, there were obtained the data on species composition of the zooocenosis of fouling and their quantitative characteristics. In zooperiphyte samples there were found 11 species from 4 classes of invertebrates: Crustacea, Mollusca, Polychaeta, and Hydrozoa. Of this number of species, the largest abundance and biomass were formed by Balanus improvisus (Balanidae) and Mytilaster lineatus (Mytilidae). The level of development of these two species determined the general indicators of zoocenosis of artificial reef fouling. The remaining species had low indicators of quantitative development, but were important for the fouling biodiversity of the Caspian Sea. There has been defined the influence of the depth of artificial reef installation on the development of fouling organisms, found their higher quantitative characteristics compared to zoobenthos, and the structure-forming species of zooperiphyton in the survey area.

Nitroxide-Containing Amphiphilic Random Terpolymers for Marine Antifouling and Fouling-Release Coatings

Two types of amphiphilic random terpolymers, poly(ethylene glycol methyl ether methacrylate)-ran-poly(2,2,6,6-tetramethylpiperidinyloxy methacrylate)-ran-poly(polydimethyl siloxane methacrylate) (PEGMEMA-r-PTMA-r-PDMSMA), were synthesized and evaluated for antifouling (AF) and fouling-release (FR) properties using diverse marine fouling organisms. In the first stage of production, the two respective precursor amine terpolymers containing (2,2,6,6-tetramethyl-4-piperidyl methacrylate) units (PEGMEMA-r-PTMPM-r-PDMSMA) were synthesized by atom transfer radical polymerization using various comonomer ratios and two initiators: alkyl halide and fluoroalkyl halide. In the second stage, these were selectively oxidized to introduce nitroxide radical functionalities. Finally, the terpolymers were incorporated into a PDMS host matrix to create coatings. AF and FR properties were examined using the alga Ulva linza, the barnacle Balanus improvisus, and the tubeworm Ficopomatus enigmaticus. The effects of comonomer ratios on surface properties and fouling assay results for each set of coatings are discussed in detail. There were marked differences in the effectiveness of these systems against the different fouling organisms. The terpolymers had distinct advantages over monopolymeric systems across the different organisms, and the nonfluorinated PEG and nitroxide combination was identified as the most effective formulation against B. improvisus and F. enigmaticus.

Control Copepod Abundances and Kilka Catch by Invasive Predator Mnemiopsis leidyi A. Agassiz, 1868 in the Southern Caspian Sea

The Caspian Sea has a variety of species and groups of aquatic animals, e.g., plankton and fishes that are exploited, unfortunately in the past decade, this sea has entered and expelled of some non-indigenous species such as ctenophore Mnemiopsis leidyi, Copepods Acartia tonsa, Balanidae Balanus improvisus and Mullets Lisa saliens have caused major changes in the Sea. One of the species got common in the coastal waters is M. leidyi with the highest biomass in summer at the temperature of 25-30 °C, and the highest abundance was observed in autumn while the minimum density was in winter of 8-10 °C. The ctenophore distribution of length frequency indicated that while 83% of the population consists of larval and immature organisms, only less than 17% belonged to the adult group in the costal waters of the Caspian. The largest size of the jelly was 70 mm long in the southern Caspian Sea in September 2002. Based on the jelly food consumption, the Nauplius, copepodites and adults of Acartia tonsa consisted 66% and bivalves was 13% in the Caspian. Therefore, it seems the reduction of the comb jelly compared to its early year's invasion was due to the reduction of edible zooplankton especially A. tonsa in the southern of the Caspian Sea. During 2001-2013, Kilka catches amount was decreased to ~15000 kg from 95000 kg in 1996 with the changes of Clupeidae species composition of Clupeonella engrauliformis to C. cultriventris caspia.

Functional morphology of cirri in the barnacle Amphibalanus improvisus (crustacea: Balanidae).

Barnacles rely heavily on their mobile cirri for food capture because of the sessile lifestyle. These filamentous food capturing devices are extended into the water current and perform undulating movements. Cuticular structures with corresponding musculature work together, to allow these highly repetitive movements. This paper studies the interplay between structure and function of the cirri using scanning electron microscopy (SEM), microcomputed tomography (µCT) and high-speed video recordings (HSV) in Amphibalanus improvisus. Barnacles use the external cuticle structures (denticles and setae) for efficient grooming, food capturing, and providing support for the muscular system responsible for movement control. Entanglement of the cirri during extension is probably avoided through an interlocking of the serrate setae on cirri IV-VI, creating a "zipper-like" effect, which was recorded here using the HSV. We analyzed the muscular arrangement using µCT and found a new flexor muscle in both the endo- and exopod of cirrus II. Supported by the intrinsic cirral muscles, the new flexor muscles may provide variable movements of the anterior cirri (cirri I-III), which is important for further food handling. Our results provide a foundation for further comparative studies of the feeding apparatus of barnacles and for possible implications in the area of bio-inspired robotics.

Polymorphism ofCaCO3and the variability of elemental composition of the calcareous skeletons secreted by invertebrates along the salinity gradient of the Baltic Sea

Biomineralization is of great importance in ecosystem functioning and for the use of carbonate skeleton as environmental proxies. Skeletal formation is controlled to different degrees by environmental parameters and biological mechanisms. While salinity is one of the most important factors affecting ecological processes and ocean physiochemistry, the goal of this investigation was to identify how salinity influences the mineral type and the concentrations of chemical elements in the whole skeleton of invertebrates from the Baltic Sea. In this model system, the surface salinity decreases from marine values (27.2) to almost fresh water (6.1). The selected organisms, mussels (Mytilus spp.), bryozoans (Einhornia crustulenta, Cribrilina cryptooecium, Cryptosula pallasiana, Electra pilosa, Escharella immersa), barnacles (Amphibalanus improvisus, Semibalanus balanoides), and polychaetes (Spirorbis tridentatus), precipitated skeleton composed of calcite and aragonite, most likely as a result of various interacting environmental and biological factors. The concentrations of all elements in bulk skeleton were highly variable between species from the same location, underlining the role of the biological mechanisms in skeletal formation. The concentration of Ca, Mg, Sr, and Na increased in the bulk skeleton of stenohaline organisms with increasing salinity, while in the bulk skeleton of euryhaline species, only the concentration of Na increased with increasing salinity. The concentrations of Mn, Ba, Cu, Pb, Y, V, Cd, and U in the skeleton of euryhaline species generally decreased at higher salinities, most likely reflecting the lower bioavailability of elements at higher salinity. However, the concentrations of elements in the skeleton of stenohaline organisms were highly variable with no clear salinity impact. This study suggests that, although the composition of skeleton of calcifying organisms along the salinity gradient of the Baltic Sea is to a large extent affected by biological mechanisms, it also reflects the responses to environmental conditions.

Мікроскопічні водорості водойм Кінбурнської піщаної коси (НПП «Білобережжя Святослава», Україна)

Taxonomical composition of microscopic algae of different reservoirs (Dnieper estuary, Kefalny, Guryansky and Cherepashy lakes, Yagorlytsky Bay) of the Kinburn sand spit of north-western part of the Black Sea (National Nature Park “Biloberezhzha of Svyatoslav”) is studied. Material tests that is collected on sandy and silty soils served as for researches, and also in becoming overgrown with of mussels Mytilus galloprovincialis Lamarck, Mya arenaria L., Cerastoderma lamarcki Reeve and Balanus improvisus Darwin, macroscopic algae (Ceramium virgatum Roth, Cladophora vagabunda (L.) Hoek, C. siwaschensis C.Meyer, Ulva intestinalis L., Polysiphonia elongata (Huds.) Harv.) of Kіnburnska braid from September in 2019 for October in 2021. On the whole it was collected and analysed 90 standards. 116 species of microscopic algae are educed, that to 74 genera, 52 families, 31 orders, 9 classes, 6 divisions, belong, 3 kingdoms and 2 empires. After systematic composition Bacillariophyta (76 species) prevailed above Cyanophyta (26), Chlorophyta (7), Dinophyta (3), Chrysophyta (3) and by Haptophyta (1). 86 species of algae were found in the microphytobenthos of Yagorlyk Bay, 56 in Dnieper estuary, 33 in Cherepashy, 22 in Guryansky and 17 in Kefalny lakes. As a result of researches it was educed 2 new and 4 rare species of microscopic algae for the aquatorium of the Black Sea.

Barrettides: A Peptide Family Specifically Produced by the Deep-Sea Sponge Geodia barretti.

Natural product discovery by isolation and structure elucidation is a laborious task often requiring ample quantities of biological starting material and frequently resulting in the rediscovery of previously known compounds. However, peptides are a compound class amenable to an alternative genomic, transcriptomic, and in silico discovery route by similarity searches of known peptide sequences against sequencing data. Based on the sequences of barrettides A and B, we identified five new barrettide sequences (barrettides C–G) predicted from the North Atlantic deep-sea demosponge Geodia barretti (Geodiidae). We synthesized, folded, and investigated one of the newly described barrettides, barrettide C (NVVPCFCVEDETSGAKTCIPDNCDASRGTNP, disulfide connectivity I–IV, II–III). Co-elution experiments of synthetic and sponge-derived barrettide C confirmed its native conformation. NMR spectroscopy and the anti-biofouling activity on larval settlement of the bay barnacle Amphibalanus improvisus (IC50 0.64 μM) show that barrettide C is highly similar to barrettides A and B in both structure and function. Several lines of evidence suggest that barrettides are produced by the sponge itself and not one of its microbial symbionts.

Genomic Characterization of the Barnacle Balanus improvisus Reveals Extreme Nucleotide Diversity in Coding Regions

Barnacles are key marine crustaceans in several habitats, and they constitute a common practical problem by causing biofouling on man-made marine constructions and ships. Despite causing considerable ecological and economic impacts, there is a surprising void of basic genomic knowledge, and a barnacle reference genome is lacking. We here set out to characterize the genome of the bay barnacle Balanus improvisus (= Amphibalanus improvisus) based on short-read whole-genome sequencing and experimental genome size estimation. We show both experimentally (DNA staining and flow cytometry) and computationally (k-mer analysis) that B. improvisus has a haploid genome size of ~ 740 Mbp. A pilot genome assembly rendered a total assembly size of ~ 600 Mbp and was highly fragmented with an N50 of only 2.2 kbp. Further assembly-based and assembly-free analyses revealed that the very limited assembly contiguity is due to the B. improvisus genome having an extremely high nucleotide diversity (π) in coding regions (average π ≈ 5% and average π in fourfold degenerate sites ≈ 20%), and an overall high repeat content (at least 40%). We also report on high variation in the α-octopamine receptor OctA (average π = 3.6%), which might increase the risk that barnacle populations evolve resistance toward antifouling agents. The genomic features described here can help in planning for a future high-quality reference genome, which is urgently needed to properly explore and understand proteins of interest in barnacle biology and marine biotechnology and for developing better antifouling strategies.

The patterns of elemental concentration (Ca, Na, Sr, Mg, Mn, Ba, Cu, Pb, V, Y, U and Cd) in shells of invertebrates representing different CaCO<sub>3</sub> polymorphs: a case study from the brackish Gulf of Gdańsk (the Baltic Sea)

Abstract. The shells of calcitic arthropod Amphibalanus improvisus; aragonitic bivalves Cerastoderma glaucum, Limecola balthica, and Mya arenaria; and bimineralic bivalve Mytilus trossulus were collected in the brackish waters of the southern Baltic Sea in order to study patterns of bulk elemental concentration (Ca, Na, Sr, Mg, Ba, Mn, Cu, Pb, V, Y, U and Cd) in shells composed of different crystal lattices (calcite and aragonite). The factors controlling the elemental composition of shells are discussed in the context of crystal lattice properties, size classes of organisms and potential environmental differences between locations. Clams that precipitate fully aragonitic shells have a clear predominance of Sr over Mg in shells, contrary to predominant accumulation of Mg over Sr in calcitic shells of barnacles. However, the barnacle calcite shell contains higher Sr concentration than bivalve aragonite. The elemental variability between size-grouped shells is different for each studied species, and the elemental concentrations tend to be lower in the large size classes compared to the smaller size classes. Biological differences between and within species, such as growth rate, feeding strategy (including feeding rate and assimilation efficiency or composition) and contribution of organic material, seem to be important factors determining the elemental accumulation in shells. Because specimens used in this study were obtained from different sampling sites within the gulf, the impact of location-specific environmental factors, such as sediment type, cannot be excluded.

Settlement and Recruitment Potential of Four Invasive and One Indigenous Barnacles in South Korea and Their Future

Invasion by nonindigenous species is a major threat to marine ecosystems. In this study, the distribution and occupied area (as a percentage) of four invasive barnacles (Amphibalanus amphitrite, Amphibalanus eburneus, Amphibalanus improvisus, Perforatus perforatus), and one indigenous (Balanus trigonus) barnacle in 13 ports in three Korean seas (East sea, Korea Strait, and Yellow Sea) were investigated. The average ratio for all five species was 11.17% in summer and 7.59% in winter, indicating a higher occupancy in summer. B. trigonus, which is an indigenous species, was found on all ports, except for one (IC). Of the invasive species, A. amphitrite was found mainly in the Yellow Sea, A. improvisus in the Korea Strait, and A. eburneus along with P. perforatus were found in the East Sea. From nonmetric multidimensional scaling (NMDS) analysis, six parameters related to water temperature and salinity were found to be significantly correlated with the distribution and occupancy status of these five barnacles. Using the six parameters as independent variables, random forest (RF) models were developed. Based on these models, the predicted future dominant invasive species were A. improvisus and A. amphitrite in the Yellow Sea and P. perforatus in the East Sea and Korea Strait. This study suggests that long-term monitoring of invasive species is crucial, and that determining the relationship between the results of monitoring and environmental variables can be helpful in predicting the damage caused by invasive species resulting from environmental changes.

Таксоцен Malacostraca акватории бухты Ласпи (Чёрное море)

The water area of Laspi Bay is located between the Cape Aya Nature Reserve and the coastal-acval complex near Cape Sarich. The benthic samples were collected during the summer period 2016–2019. The taxonomic diversity and current condition of the higher crustaceans, which live on the loose littoral and sublittoral bottoms of the bay, was assessed. 41 species of Malacostraca have been identified. They belong to 6 groups. In bay other Arthropoda representatives were found: Amphibalanus improvisus (Darwin, 1854) and Harpacticoida. The average biomass of higher crustaceans was 0.454±0.228 g/m2. The main role in its formation is played by Decapoda and is dominated by Diogenes pugilator. The average number of Malacostraca was 280±158 ind./m2. The highest percentage of occurrence and high density of settlement were recorded for Amphipoda. The ranked series by density index was headed by D. pugilator, Echinogammarus foxi, Centraloecetes dellavallei and Echinogammarus karadagiensis. The highest numbers were recorded at stations in the flood zone (0–0.5 m). High abundance and biomass concentrations of Malacostraca were recorded at the stations with sand and pebbles.

Current distribution and abundance of Austrominius modestus (Darwin, 1854) and other non-indigenous barnacles along the northern coast of Portugal

The presence of non-indigenous barnacles on the north coast of Portugal was reported for the first time on the beginning of the second half of the past century. Since then, there is a lack of information to evaluate changes in the abundance and/or distribution of these barnacles. The aim of this study is to evaluate the current distribution and abundance of non-indigenous species of barnacles in northern Portugal, providing quantitative data that will be useful for future studies as baseline. To achieve this aim we explored the presence of non-indigenous species of barnacles using a quantitative sampling design along the coast of North Portugal. Three species of non-indigenous barnacles were found: Amphibalanus amphitrite, Amphibalanus improvisus and Austrominius modestus. The only species that showed a widespread distribution on the study area was A. modestus, with similar abundances in all the studied estuaries. On the other hand, A. improvisus and A. amphitrite showed a very limited distribution. This study provides the first quantitative data for these species in north Portugal, that will be useful to explore the evolution of their populations in the future.

Biodiversity of epifauna in the ports of Southern Baltic Sea revealed by study of recruitment and succession on artificial panels

Ports are highly dynamic environments that are under substantial anthropogenic pressure generated by activities related to the fishery, transhipment of cargo and passenger traffic. Thus, seaports are exposed to physical disturbances, chemical pollution and biological invasions. Yet knowledge about biotic part and the influence of anthropogenic pressure on it in seaports often does not exist. The main aim of this study was to assess the biodiversity of the hard-bottom epifauna by examination of the course of the recruitment and succession processes in the poorly known port basin ecosystem of the southern Baltic Sea at the ports of Gdańsk, Gdynia and Władysławowo. We wanted to test whether the different port areas had their unique species diversity and compositions. In all investigated ports we found relatively low biodiversity but high recruitment activity of sessile fauna. Six epifaunal species were observed, and Amphibalanus improvisus was consistently the dominant species (up to 47,126.5 ± 2747.1 SD individuals per 225 cm2 in July in Gdynia port). Seasonality was found to be the main factor shaping recruitment and further development of the sessile assemblages, and the seasonal sequences of epifaunal occurrence were similar in the three examined ports. Furthermore, the epifauna of all ports showed homogenous species richness, composition and abiotic characteristics, although in the Władysławowo port, which is more exposed to the open sea, a higher abundance of meroplankton and greater shares of accessory species (Mytilus spp., Limecola balthica, Cerastoderma glaucum and Mya arenaria) were found. The assemblage structures of the ports resembled those of nearby natural system (Gulf of Gdańsk); thus, the port ecosystem seems to be an integral part of the surrounding natural habitat. Two years of monthly observations did not reveal any new non-native species in the examined study area.

Sol-Gel-Based Hybrid Materials as Antifouling and Fouling-Release Coatings for Marine Applications.

Hybrid materials (HMs) offer unique properties as they combine inorganic and organic components into a single material. Here, we developed HM coatings for marine antifouling applications using sol-gel chemistry and naturally occurring polysaccharides. The coatings were characterized by spectroscopic ellipsometry, contact angle goniometry, AFM, and ATR-FTIR, and their stability was tested in saline media. Marine antifouling and fouling-release properties were tested in laboratory assays against the settlement of larvae of the barnacle Balanus improvisus and against the settlement and removal of the diatom Navicula incerta. Furthermore, laboratory data were confirmed in short-term dynamic field assays in Florida, USA. All hybrid coatings revealed a superior performance in the assays compared to a hydrophobic reference. Within the hybrids, those with the highest degree of hydrophilicity and negative net charge across the surface performed best. Alginate and heparin showed good performance, making these hybrid materials promising building blocks for fouling-resistant coatings.