PATTERNS OF EPIPELIC ALGAL DISTRIBUTION IN AN ACIDIC ADIRONDACK LAKE1

The biovolume and species composition of epipelic algae along sediment depth gradients were sampled seasonally in an acidic oligotrophic lake in the Adirondack Park in New York State. The epipelic algal community of Woods Lake (Herkimer Co., NY) was dominated by diatoms and cyanobacteria. Distinct depth zonation patterns of community composition were evident. Total algal biovolume increased with depth due to a dense cyanobacterial mat on the sediments in deeper water (5–8 m). This mat was dominated by a single species of cyanobacteria, Hapalosiphon pumilus (Kütz.) Kirchner, which accounted for the late summer maximum in total biovolume at 7 m. The shallower (1–4 m) epipelic communities were dominated by diatoms, which showed a spring maximum in total biovolume and were dominated by Fragilaria acidobiontica Charles, Navicula tenuicephala Hust. and N. subtilissima Cl.     

The invasive green alga Avrainvillea sp. transforms native epifauna and algal communities on a tropical hard substrate reef

Some introduced species compete directly with native species for resources and their spread can alter communities, while others do not proliferate and remain benign. This study compares community structure and diversity in adjacent areas dominated by the introduced alga Avrainvillea sp. or native algal species on a hard substrate reef. The biomass and species composition of 15 paired plots (30 in total, plot type based on dominance of Avrainvillea sp. or native species) were quantified. Plots dominated by Avrainvillea sp. had a significantly different assemblage of species characterized by lower algal diversity, mostly Dictyota spp. and Laurencia sp., and a higher abundance and diversity of invertebrates, such as small arthropods, polychaetes, and brittlestars. These results suggest that as Avrainvillea sp. becomes more abundant on hard substrate reefs, it will engineer a different community composed of algal epiphytes and an invertebrate assemblage more typically associated with algae in soft sediments.     

Discrimination of marine algal taxonomic groups using delayed fluorescence spectroscopy

We present a method for in situ monitoring of phytoplankton composition changes in a marine environment. The method is based on delayed fluorescence excitation spectra analyzed with CHEMTAX software, which is generally used for determination of phytoplankton communities with HPLC pigment data. Delayed fluorescence (DF) is a photosynthetic parameter that can only be measured in living cells. Algal DF excitation spectra are group-specific, based on their composition of photosynthetic pigments.DF excitation spectra of 14 marine algal species from different families were measured with a delayed fluorescence spectrometer. Mixtures were prepared from northern Adriatic algal species representing six taxonomic groups: dinoflagellates (Prorocentrum minimum), diatoms (Skeletonema costatum), cyanobacteria (Synechococcus sp.), prasinophytes (Micromonas sp.), cryptophytes (Teleaulax sp.), and prymnesiophytes (Isochrysis galbana). The DF excitation spectra (DFS) and HPLC pigment compositions of the mixtures were analyzed with CHEMTAX software. The prediction power of DFS–CHEMTAX method was comparable to HPLC–CHEMTAX.     

Elevated nutrients change bacterial community composition and connectivity: high throughput sequencing of young marine biofilms

Biofilms are integral to many marine processes but their formation and function may be affected by anthropogenic inputs that alter environmental conditions, including fertilisers that increase nutrients. Density composition and connectivity of biofilms developed in situ (under ambient and elevated nutrients) were compared using 454-pyrosequencing of the 16S gene. Elevated nutrients shifted community composition from bacteria involved in higher processes (eg Pseudoalteromonas spp. invertebrate recruitment) towards more nutrient-tolerant bacterial species (eg Terendinibacter sp.). This may enable the persistence of biofilm communities by increasing resistance to nutrient inputs. A core biofilm microbiome was identified (predominantly Alteromonadales and Oceanospirillales) and revealed shifts in abundances of core microbes that could indicate enrichment by fertilisers. Fertiliser decreased density and connectivity within biofilms indicating that associations were disrupted perhaps via changes to energetic allocations within the core microbiome. Density composition and connectivity changes suggest nutrients can affect the stability and function of these important marine communities.     

Atrazine metabolism and herbicidal selectivity

Metabolism of the herbicide 2-chloro-4-ethylamino-6-isopropylamino-s-triazine (atrazine) was investigated in resistant corn (Zea mays L.) and sorghum (Sorghum vulgare Pers.), intermediately susceptible pea (Pisum sativum L.), and highly susceptible wheat (Triticum vulgare Vill.) and soybean (Glycine max Merril.). This study revealed that 2 possible pathways for atrazine metabolism exist in higher plants. All species studied were able to metabolize atrazine initially by N-dealkylation of either of the 2 substituted alkylamine groups. Corn and wheat, which contain benzoxazinone, also metabolized atrazine initially by hydrolysis in the 2-position of the s-triazine ring to form hydroxyatrazine. Subsequent metabolism by both pathways resulted in the conversion of the parent atrazine to more polar compounds and eventually into methanol-insoluble plant residue. No evidence for s-triazine ring cleavage was obtained.

Both pathways for atrazine metabolism appear to detoxify atrazine. The hydroxylation pathway results in a direct conversion of a highly phytotoxic compound to a completely non-phytotoxic derivative. The dealkylation pathway leads to detoxication through one or more partially detoxified, stable intermediates. Therefore, the rate and pathways of atrazine metabolism are important in determining the tolerance of plants to the herbicide. Both quantitative and qualitative differences in atrazine metabolism were detected between resistant, intermediately susceptible, and susceptible species. The ability of plants to metabolize atrazine by N-dealkylation and the influence of this pathway in determining tolerance of plants to atrazine are discussed.

     

Composition and dynamics of a highly diverse diatom assemblage in a limestone stream

The algal assemblages of a small limestone stream were studied for a year at monthly intervals. Algal standing crop was permanently high (mean concentration of 158 mg Chl-a · m^–2), but it reached the maximum values in spring and summer. Diatoms were dominant in the algal assemblages throughout this time, and more than one hundred species were recorded during the survey. Most of them are characteristic of hard waters, but others, mainly occurring in summer, have been observed elsewhere in moderately halophile waters.A striking succession was observed in the diatom assemblage in the stream in each season. This succession, with a maximum in summer, was mainly related with the lessening in flow and the increase in water mineralization. Moreover, the diversity of the samples increased sharply from April 1982 to July 1983. In fact, a progressive increase in salinity tolerant species could be observed from winter and spring to summer. Nitzschia sociabilis, Navicula gregaria, Navicula lanceolata and Gomphonema olivaceum were the most abundant species in winter, whereas Achnanthes minutissima reached its maximum in spring and Navicula schroeterii, Nitzschia thermaloides and Cyclotella meneghiniana were some of the most abundant in summer.     

Marine invertebrates in an algal succession. III. Mechanisms linking habitat complexity with diversity

A diverse community of marine invertebrates is associated with suceessional algal mats in an intertidal boulder field in southern California. Species richness and abundance of invertebrates increased from early to middle suceessional stages, then remained similar into the later stage. These changes are paralleled by those in the physical structure (biomass and surface area) of the algae. Increased complexity of the algal physical structure probably influenced the associated invertebrate community through several mechanisms. (1) It decreased mortality caused by predation from fish and crabs. (2) It reduced the severity of physical stresses, primarily wave shock. (3) It increased the accumulation of those individuals and species transported passively by wave action. (4) In mobile species, selection of algal substrates was largely based on physical aspects of algal structure. While no species tested appeared to select particular algal species. all actively chose algal clumps of high biomass. All four mechanisms result in the accumulation of greater numbers of individuals in algal mats with higher biomass and surface area. Because a larger sample of the available pool of individuals is collected, more species are found in a given area of algal mat when the structure is more complex. The suceessional patterns of change in species richness of the invertebrate community seem to result from this sampling phenomenon. Laboratory experiments and correlations in abundance between pairs of species gave no evidence of any competitive interactions. Any apparent “structure” in this assemblage seems to be the result of the summation of individual responses to changing algal physical structure during succession.     

Factors Affecting Development of Peroxisomes and Glycolate Metabolism among Algae of Different Evolutionary Lines of the Prasinophyceae

Leaf-type peroxisomes are not present in the primitive unicellular Prasinophycean line of algae but are present in the multicellular algae Mougeotia, Chara, and Nitella, which are in the one evolutionary line, Charophyceae, that led to higher plants. Processes related to glycolate metabolism that may have been modified or induced with the appearance of peroxisomes have been examined. The algal dissolved inorganic carbon-concentrating mechanism and alkalization of the medium during photosynthesis were not lost when peroxisomes appeared in the members of the Charophycean line of algae. Therefore, it is unlikely that lowering of the CO2 concentration in the environment was a major factor in the evolutionary appearance of peroxisomes. Multicellular Mougeotia, early members of the Charophycean line of algae, have peroxisomes, but they excrete excess glycolate into the medium. The cytosolic pyruvate reductase for D-lactate synthesis and the glycolate dehydrogenase activity almost disappeared when peroxisomal glycolate oxidase, which also oxidizes L-lactate, appeared. These biochemical changes do not indicate what caused the induction of leaf-type peroxisomes in this evolutionary line of algae. The oxygenase activity of ribulose-1,5-bisphosphate carboxylase/oxygenase and glycolate oxidase require about 200 to 400 [mu]M O2 for 0.5 Vmax. These high-O2-requiring steps in glycolate metabolism would have functioned faster with increasing atmospheric O2, which might have been the causative factor in the induction of peroxisomes.     

Do changes in seaweed biodiversity influence associated invertebrate epifauna?

Most investigations of biogenic habitat provision consider the promotion of local biodiversity by single species, yet habitat-forming species are often themselves components of diverse assemblages. Increased prevalence of anthropogenic changes to assemblages of habitat-forming species prompts questions about the importance of facilitator biodiversity to associated organisms. We used observational and short-term (30 days) manipulative studies of an intertidal seaweed system to test for the implications of changes in four components of biodiversity (seaweed species richness, functional group richness, species composition, and functional group composition) on associated small mobile invertebrate epifauna. We found that invertebrate epifauna richness and abundance were not influenced by changes in seaweed biodiversity. Invertebrate assemblage structure was in most cases not influenced by changes in seaweed biodiversity; only when algal assemblages were composed of monocultures of species with ‘foliose’ morphologies did we observe a difference in invertebrate assemblage structure. Correlations between algal functional composition and invertebrate assemblage structure were observed, but there was no correlation between algal species composition and invertebrate assemblage structure. These results suggest that changes in seaweed biodiversity are likely to have implications for invertebrate epifauna only under specific scenarios of algal change.     

Pathways for algal recolonization in seasonally‐flowing streams

1. In semi‐arid climates, seasonally‐flowing streams provide most of the water required for human use, but knowledge of how water extraction affects ecological processes is limited. Predicted alterations in stream flows associated with the impacts of climate change further emphasize the need to understand these processes. Benthic algae are an important base for stream food webs, but we have little knowledge of how algae survive dry periods or respond to altered flow regimes. 2. We sampled 19 streams within the Grampians National Park, south‐eastern Australia and included four components: a survey of different drought refuges (e.g. permanent pools, dry biofilm on stones and dry leaf packs) and associated algal taxa; a survey of algal regrowth on stones after flows recommenced to determine which refuges contributed to regrowth; reciprocal transplant experiments to determine the relative importance of algal drift and regrowth from dry biofilm in recolonization; direct measurement of algal drift to determine taxonomic composition in relation to benthic assemblage composition. 3. Algae showed little specificity for drought refuges but did depend on them; no species were found that were not present in at least one of the perennial pool, dry biofilm or leaf pack refuges. Perennial pools were most closely correlated with the composition of algal assemblages once flows resumed, but the loss or gain of perennial pools that might arise from stream regulation is unlikely to affect the composition of algal regrowth. However, regulated streams were associated with strong increases in algal density in dry biofilm, including increased densities of Cyanobacteria. 4. A model for algal recolonization in seasonally‐flowing streams identified three pathways for algal recolonization (drift‐dependent, dry biofilm‐dependent and contributions from both), depending on whether streams are diatom‐dominated or dominated by filamentous algae. The model predicted the effects of changes to stream flow regimes on benthic algal recolonization and provides a basis for hypotheses testable in streams elsewhere.     

Effects of oxytetracycline on populations and community metabolism of an aquatic microcosm

To investigate the ecological impacts of a widely-used antibiotic agent oxytetracycline (OTC), we prepared an aquatic microcosm consisting of two green algae (Chlorella sp. and Scenedesmus sp.), a blue-green alga (Tolypothrix sp.), a protozoan (Cyclidium sp.), two rotifers (Philodina sp. and Lecane sp.), an aquatic oligochaete (Aeolosoma hemprichi), and bacteria. We investigated the effects of OTC on population abundance of composite species, gross primary production (GPP), and community respiration (CR). We linked population abundance, GPP and CR to understand the relationship between these measures. First, ‘experimental respiration rate of heterotrophs’ (HR_exp) was obtained by CR minus algal respiration that is calculated by 0.35 × GPP. Next, the population respiration of each heterotroph was calculated from the direct measure of population abundance and the assumed constant of per-capita respiration. We defined the sum of the population respirations across all heterotrophs as ‘theoretical respiration rate of heterotrophs’ (HR_theo). Finally, relative community metabolism (RCM) of the heterotrophic community was obtained by calculating the ratio of HR_exp to HR_theo that indicates changes in specific respiration rates as a whole in the community. The influence of OTC on RCM was larger than on CR, thus the effect of OCT on the metabolism of heterotrophs was far more severe than expected from CR. RCM can magnify the rate of change in the original data, and facilitate the detection of influences in ecotoxicological studies.     

The development of marine biofilms on two commercial non-biocidal coatings: a comparison between silicone and fluoropolymer technologies

The antimicrobial performance of two fouling-release coating systems, Intersleek 700? (IS700; silicone technology), Intersleek 900? (IS900; fluoropolymer technology) and a tie coat (TC, control surface) was investigated in a short term (10 days) field experiment conducted at a depth of ca 0.5 m in the Marina Bandar Rawdha (Muscat, Oman). Microfouling on coated glass slides was analyzed using epifluorescence microscopy and adenosine-5'-triphosphate (ATP) luminometry. All the coatings developed biofilms composed of heterotrophic bacteria, cyanobacteria, seven species of diatoms (2 species of Navicula, Cylindrotheca sp., Nitzschia sp., Amphora sp., Diploneis sp., and Bacillaria sp.) and algal spores (Ulva sp.). IS900 had significantly thinner biofilms with fewer diatom species, no algal spores and the least number of bacteria in comparison with IS700 and the TC. The ATP readings did not correspond to the numbers of bacteria and diatoms in the biofilms. The density of diatoms was negatively correlated with the density of the bacteria in biofilms on the IS900 coating, and, conversely, diatom density was positively correlated in biofilms on the TC. The higher antifouling efficacy of IS900 over IS700 may lead to lower roughness and thus lower fuel consumption for those vessels that utilise the IS900 fouling-release coating.     

周丛藻类及其在水质净化中的应用

周丛藻类广泛存在于自然界水体中,具有生物量大、生态功能强、水质响应灵敏等特征.周丛藻类通过吸收代谢利用、吸附和络合等过程去除水体污染物质,用于水质净化,具有耐污能力强,N、P去除效果好,藻类细胞回收利用价值高等优点,推广应用前景广阔.近年开发的藻丛刷系统、周丛藻类 生物膜系统和周丛藻类水产养殖系统等已经成功用于畜禽水产养殖废水、生活污水处理.而周丛藻类的生存规律、对污染物浓度的生理响应机理和污染物质吸收利用的分子生物学机制仍有待进一步研究.     

Effects of gastropod grazers on recruitment and succession of an estuarine assemblage: a multivariate and univariate approach

Grazers have been shown to affect assemblages of species in many habitats. Here we studied the effects of the gastropod grazers, Austrocochlea porcata and Bembicium auratum, on intertidal estuarine assemblages in a sheltered bay in New South Wales, Australia. We examined the effects of gastropods on individual species and on the assemblage as a whole. The multivariate response was compared with data on succession in these assemblages to estimate potential effects of grazers on succession. The experiment was repeated several times to determine the generality of grazer effects in the light of possible variation in the timing or intensity of recruitment. There were different responses of individual species to the presence of grazers. Grazers reduced the abundance of ephemeral algal species, bryozoans, copepods, insect larvae and Balanus spp. barnacles. They had a positive effect on oysters and spirorbids and no effect on the barnacles Elminius covertus and Hexaminius spp. These effects were consistent through time. Multivariate analyses confirmed that grazers caused significant changes to whole assemblages and that these effects were far-reaching and not only caused by changes to algal species. The removal of grazers appeared to neither speed up nor slow down succession, but rather caused a completely different assemblage to develop. Apparent important mechanisms affecting the composition of animal species when grazers were removed included accumulation of sediments and detritus and pre-emption of space by algae. Received: 13 May 1996 / Accepted: 1 September 1996     

Response of phytoplankton populations to aquatic treatment byLemna gibba

Aquatic treatment indicated that the efficiency ofL. gibba in algal removal was higher in mixtures of Nile and wastewater systems and the percent algal reduction ranged from 86 to 90%. The maximum percentage of algal removal was achieved with a water system with an equal mixture of Nile and wastewater, this was followed by the water system with Nile to wastewater in a ratio of 1∶3 (89%). The data further revealed that the most highly predominant species were contributed byBacillariophyta. L. gibba treatment of the wastewater induced a reduction in the total species number of phytoplankton populations to only 5 species of diatoms with the order of dominance as follows:Synedra ulna, Navicula cryptocephala, Nitzschia acicularis, Melosira granulatus andCyclotella glomerata.     

鲢对藻类摄食效应的室内模拟研究

为研究鲢(Hypophthalmichthys molitrix)对藻类的摄食作用, 采用小环藻(Cyclotella)、小球藻(Chlorella)、微囊藻(Microcystis)和东湖原水开展了小规格鱼种的养殖试验, 对鲢摄食和排泄物进行了研究。结果显示: 在3 种纯培养藻种投喂下鲢存活率从高到低依次是小环藻组 小球藻组 微囊藻组;相应地, 鲢对藻的平均摄食率排序也是小环藻组 小球藻组 微囊藻组。在显微镜下观察粪便发现大部分小环藻为空壳, 一部分小球藻外部形态结构不完整, 外部形态完整的小球藻则色泽暗淡、内部结构紊乱, 微囊藻没有明显变化;3 种藻类细胞的受损率分别为20.04%、7.13%和1.97%。叶绿素荧光活性显示, 粪便中小环藻基本失去光合活性, 小球藻活性极显著降低(P0.01), 微囊藻活性明显降低(P0.05), 东湖原水处理组光合活性较对照极显著降低(P0.01)。对东湖水饲喂试验组排泄物的检测发现, 浮鞘丝藻Planktolyngya、鱼腥藻Anabeana(有破损)、假鱼腥藻Pseudoanabaena 和颤藻Oscillatoria 细胞受损严重;空星藻Coelastrum 和盘星藻Pediastrum 细胞部分破损;针杆藻Synedra、小环藻、桥弯藻Cymbella 和舟形藻Navicula 多为空壳。鱼粪中平裂藻Merismopedia、微囊藻、浮鞘丝藻、鱼腥藻、颤藻、卵囊藻Oocystis、栅藻Scenedesmus 和衣藻Chlamydomonas 在重新培养后恢复了生长。本研究显示硅藻尤其是小环藻、针杆藻和舟形藻对鲢摄食最敏感;栅藻、卵囊藻和平裂藻对摄食压力不敏感。研究表明鲢捕食对藻类群落结构有明显的改变效应, 利用鲢的滤食进行藻类群落调节和水华防控具有可行性。       

Responses of foraminiferal assemblages to ENSO climate patterns on bank reefs of northern Bahia,Brazil: A 17-year record

Benthic Foraminifera were assessed in Rose Bengal-stained sediment samples collected annually from 1995 to 2011 at four shallow bank reefs in Northern Bahia (Brazil). The assemblage was represented by 284 species and 88 genera, the most diverse genera being Quinqueloculina (46 spp.), Triloculina (24 spp.), Articulina (13 spp.), Textularia (11 spp.), and Elphidium (10 spp.). Significant differences in densities of live foraminifers in the sediments were observed among years, though not between reefs. Mean densities and diversities declined by ∼90% during the 1997–8 El Niño event compared with the two previous years, then rebounded during the strong La Niña years of 1999–2000, with rapid recovery of populations of small, heterotrophic foraminifers in the assemblage. After 2000, mean densities and diversities fluctuated, with lows following both the 2006–7 and 2009–10 weak El Niño events, but not so pronounced as during the 1997–8 event. Multivariate analysis clearly formed four separate groupings representing strong (hot, dry) and weak El Niño (dry) years, “normal” years, and strong La Niña (high rainfall) years. The FoRAM Index (FI), which is a single-metric index for water quality associated with reef accretion, provided additional insights into assemblage responses. The FI compares relative abundances of three functional groups of benthic foraminifers: characteristic reef-dwelling larger foraminifers that host algal endosymbionts, the ubiquitous heterotrophic smaller taxa, and specifically stress-tolerant heterotrophic taxa. The striking decline in overall densities during El Niño years likely reflects reduced food supply for the heterotrophic taxa, associated with higher temperatures and reduced runoff. Decline in the taxa that host algal symbionts is consistent with reports of extensive coral bleaching, likely related to photo-oxidative stress caused by higher temperatures and increased water transparency. The significant changes in assemblage structure and composition recorded during this 17-year study demonstrate the major influence of climatic variability associated with the El Niño/La Niña-Southern Oscillation.     

Gastropod grazers and nutrients,but not light,interact in determining periphytic algal diversity

The potential interactions of grazing, nutrients and light in influencing autotroph species diversity have not previously been considered. Earlier studies have shown that grazing and nutrients interact in determining autotroph species diversity, since grazing decreases species diversity when nutrients (i.e. N or P) limit autotroph growth, but increases it when nutrients are replete. We hypothesized that increased light intensities would intensify the interactions between grazing and nutrients on algal species diversity, resulting in even stronger reductions in algal species diversity through grazing under nutrient–poor conditions, and to even stronger increases of algal species diversity through grazing under nutrient-rich conditions. We studied the effects of grazing (absent, present), nutrients (ambient, N + P enriched) and light (low light, high light) on benthic algal diversity and periphyton C:nutrient ratios (which can indicate algal nutrient limitation) in a factorial laboratory experiment, using the gastropod grazer Viviparus viviparus. Grazing decreased algal biomass and algal diversity, but increased C:P and N:P ratios of periphyton. Grazing also affected periphyton species composition, by decreasing the proportion of Spirogyra sp. and increasing the proportion of species in the Chaetophorales. Grazing effects on diversity as well as on periphyton N:P ratios were weakened when nutrients were added (interaction between grazing and nutrients). Chlorophyll a (Chl a) per area increased with nutrient addition and decreased with high light intensities. Light did not increase the strength of the interaction between grazing and nutrients on periphytic algal diversity. This study shows that nutrient addition substantially reduced the negative effects of grazing on periphytic algal diversity, whereas light did not interact with grazing or nutrient enrichment in determining periphytic algal diversity.     

Combinatorial materials research applied to the development of new surface coatings V. Application of a spinning water-jet for the semi-high throughput assessment of the attachment strength of marine fouling algae

In order to facilitate a semi-high throughput approach to the evaluation of novel fouling-release coatings, a 'spinjet' apparatus has been constructed. The apparatus delivers a jet of water of controlled, variable pressure into the wells of 24-well plates in order to facilitate measurement of the strength of adhesion of algae growing on the base of the wells. Two algae, namely, sporelings (young plants) of the green macroalga Ulva and a diatom (Navicula), were selected as test organisms because of their opposing responses to silicone fouling-release coatings. The percentage removal of algal biofilm was positively correlated with the impact pressure for both organisms growing on all the coating types. Ulva sporelings were removed from silicone elastomers at low impact pressures in contrast to Navicula cells which were strongly attached to this type of coating. The data obtained for the 24-well plates correlated with those obtained for the same coatings applied to microscope slides. The data show that the 24-well plate format is suitable for semi-high throughput screening of the adhesion strength of algae.     

Effect of light and temperature on biomass, photosynthesis and capsular polysaccharides in cultured phototrophic biofilms

Phototrophic biofilms seem to be suitable candidates for tertiary wastewater treatment due to their high uptake capacity for nutrients and other pollutants, also taking into account the time and cost savings derived from easy procedures for biomass harvesting. Biomass accrual, structure, and physiology of biofilms affect the efficiency of nutrient removal by its microbial community. Here, we construct a biofilm consisting of a cyanobacterium Synechocystis sp. and the green alga Chlorococcum sp. and determine the effect of combined variations of irradiance and temperature on the biofilm structure and function. The two species were isolated from phototrophic biofilms naturally developing in an Italian wastewater treatment plant and grown in a microcosm designed for biofilm investigations. Phototrophic biomass accumulation, percent species composition, photosynthetic response and the amount and composition of capsular polysaccharides (CPS), including anionic residues, are reported. The results showed that biofilm development required relatively moderate irradiances (60 μmol photons m⁻² s⁻¹) below which development was arrested. Both light and temperature had a strong effect on the composition of each species to the biofilm. The CPS compositions also changed with temperature, light and species composition. The CPS of the green-algal-dominated biofilm had the higher uronic acid content indicating a potential to exploit green algae in the treatment of waste contaminated with heavy metals. Given the knowledge of the response of certain species to light and temperature combinations, it may be possible to construct biofilms of known species and CPS composition to use them for specific applications.