Phytoplankton Research Articles

Mechanical properties Of Biocomposite Based On PVA Reinforced Phytoplankton For eco-friendly materials

The scientific advances and new technologies are made along with people’s increasing understanding of the environment. Eco-friendly has become the most important feature as a result of various scientific investigations and new products. This research is to produce a PVA biocomposite reinforced with phytoplankton (PP) that has good mechanical strength and is environmentally friendly. This biocomposite will be manufactured using the die casting method. The composition variation used in this study involves various comparisons between PVA material and phytoplankton reinforcement (PP) with compositions of 1gr, 1.5gr, and 2gr. These materials were then mixed using distilled water in a certain proportion (100 ml) after the PVA was dissolved. The findings demonstrated that the tensile characteristics tensile strength of the PVA matrix were significantly affected by the addition of PP. The findings of the research include the conclusion that, when compared to other composition variations, the biocomposite composition with 2 gr PP exhibits the best performance. The biocomposite exhibited a tensile strength of 39.1 MPa, indicating that the material has high enough mechanical strength for certain applications. These findings suggest that phytoplankton PVA biocomposites have potential as an environmentally friendly material alternative that has adequate mechanical properties. The use of phytoplankton as reinforcement is an example of how natural materials can be utilized to replace or reduce the use of synthetic materials that are more detrimental to the environment. This biocomposite can be a potential eco-friendly plastic with continued development.

Vertical patterns of chlorophyll a in the euphotic layer are related to mesoscale eddies in the South China Sea

Phytoplankton closely connects with the hydrodynamics and biogeochemical environment of the ocean. While research focusing on both the physiochemical factors and hydrodynamics regulating phytoplankton has already been conducted, the coupling mechanism between mesoscale eddies and the vertical distribution of phyto plankton in the South China Sea (SCS) is still not well understood. Here, phytoplankton was studied under one weak-cold and two warm eddies along the 18°N transect in the SCS. The results show that the vertical distribution of chlorophyll (chl-a) presented a similar pattern at all four sampling stations. The mixed layer is less than 50 m. It is the same as the meridional salinity gradients that may be distinguished above a depth of 60 m. The subsurface chlorophyll maximum at the edge of a warm (WI) and cold eddy (CI) at E413 and E411 was shallower than that at the edge of a warm eddy (WII) at E407 and E409, indicating that temperature and salinity may be the important driving factors. On the whole, mesoscale eddies had a significant influence on the vertical pattern of chl-a in the SCS during the study period.

Statistical approaches to explore the linkages between physicochemical parameters and BQEs, and set river nutrient threshold concentrations in Hungary

Abstract The objective of the Water Framework Directive (WFD) is to achieve good ecological status in surface waters by 2027. To make a proper evaluation of the ecological status of watercourses, it is necessary to harmonize class boundaries for chemical and biological quality elements (BQEs). This paper aims to explore the linkages between physicochemical parameters and BQEs and set river nutrient threshold concentrations that support good ecological status. Regression and mismatch methods were applied to find the relationship between phytoplankton (PP) and phytobenthos (PB) ecological quality ratio and mean total phosphorus (TP) and total nitrogen (TN) concentrations. Nutrient thresholds have been suggested for several water types, which are varied in the case of highland rivers 1.8–6.2 mg TN/l, 180–400 μg TP/l; in the case of lowland rivers 1.4–5.0 mg TN/l, and 100–350 μg TP/l. These values are similar to what other studies found, but the relationship between biology and nutrients was weaker. Besides nutrients, additional data of measured dissolved organic carbon, 5-day biochemical oxygen demand, chemical oxygen demand with potassium permanganate method, and information about hydromorphological features were involved in the analysis. The research demonstrates that random forest can be used as a nonlinear, multiparametric model for predicting biological class from five variables with 35–81% error for PP and with 18–47% error for PB.

Modelling the Influence from Biota and Organic Matter on the Transport Dynamics of Microplastics in the Water Column and Bottom Sediments in the Oslo Fjord

The fate of microplastics (MP) in seawater is heavily influenced by the biota: the density of MP particles can be changed due to biofouling, which affects sinking, or MP can be digested by zooplankton and transferred into fecal pellets with increased sinking rate. We hypothesize that seasonal production and degradation of organic matter, and corresponding changes in the plankton ecosystem affect the MP capacity for transportation and burying in sediments in different seasons. This is simulated with a coupled hydrodynamical-biogeochemical model that provides a baseline scenario of the seasonal changes in the planktonic ecosystem and changes in the availability of particulate and dissolved organic matter. In this work, we use a biogeochemical model OxyDep that simulates seasonal changes of phytoplankton (PHY), zooplankton (HET), dissolved organic matter (DOM) and detritus (POM). A specifically designed MP module considers MP particles as free particles (MPfree), particles with biofouling (MPbiof), particles consumed by zooplankton (MPhet) and particles in detritus, including fecal pellets (MPdet). A 2D coupled benthic-pelagic vertical transport model 2DBP was applied to study the effect of seasonality on lateral transport of MP and its burying in the sediments. OxyDep and MP modules were coupled with 2DBP using Framework for Aquatic Biogeochemical Modelling (FABM). A depletion of MP from the surface water and acceleration of MP burying in summer period compared to the winter was simulated numerically. The calculations confirm the observations that the “biological pump” can be one of the important drivers controlling the quantity and the distribution of MP in the water column.

Assessment of Environmental Parameters in Pre- and Post-Monsoons at Chabahar Bay, Gulf of Oman

This study is the first investigation to assess the variations of physical and chemical characteristics and biodiversity of planktons in offshore water column and chlorophyll-a and b, during the two monsoons at Chabahar Bay, to evaluate the water quality. To this end, 27 surface water samples in pre-monsoon (May, 2012) and totally 60 surface and deep water samples in post-monsoon (December, 2012) were collected from 9 and 10 stations at depths between 3.8 to 13.6 m in Chabahar Bay, respectively. The results showed that water salinity and pH with low variations were relatively higher in post-monsoon. The averages of water alkalinity levels in pre- (2.42±0.02 mmol H+/kg) and post- (2.44±0.01 mmol kg-1) monsoons were comparable to that of oceanic surface water (2-2.5 mmol H+/kg). In this study, 66 phytoplankton genus and species belonging to 13 groups were identified in pre-monsoon. Results demonstrated that nutrients were at higher levels inside the Chabahar Bay. Moreover, the physicochemical parameters of water samples were investigated and compared with international standards and data from other marine ecosystems. The results indicated that the water quality falls within the stipulated range of acceptability and sampling area can be classified as a good, stable, and healthy aquatic ecosystem.

Use of Phytoplankton Enzyme in the Artificial Lake as Indicator of Pollution

Use of Phytoplankton Enzyme in the Artificial Lake as Indicator of Pollution

Interannual Changes in Phytoplankton of the Iriklinsky Reservoir

The interannual changes in the phytoplankton (PP) of the upper and lower parts of the Iriklinsky reservoir during different seasons of the vegetation period are described, depending on the level regime, inflow, discharge of water, and its temperature. The correlations show the leading role of these factors. It was revealed that, in May, an increase in the inflow and water level leads to the depletion of the specific number of phytoplankton species and biomass, in contrast to the situation in July and October, when an increase in these indicators is observed. It is shown that the features of the ratio of the number of species and the biomass of phytoplankton in the upper and lower reaches are related to the level and discharge modes, as well as to water temperature.

A Charecteristics of Marine Environments in a Blood Cockle Farms of the Northwestern Yeoja Bay, Korea 2. Spatio-temporal Distribution of Water Quality and Phytoplankton Community

A Charecteristics of Marine Environments in a Blood Cockle Farms of the Northwestern Yeoja Bay, Korea 2. Spatio-temporal Distribution of Water Quality and Phytoplankton Community

Influence of temperature on the aquatic biota

Detailed analysis of temperature indicators of Kremenchug reservoir in August showed a tendency to increase the coefficient of their variation (Cv=10.69–13.97%). This indicates the unstability and stress of the temperature conditions of the aquatic environment for living organisms. First of all, it will affect the organisms of near-flood layers of water which are in direct contact with unstable air masses. (Cv=28.45–31.45%). Blue-green algae species which were the most resistant to temperature fluctuations are Microcystis aeruginosa Kutz. emend. Elenkin and Anabaena flos-aquae sp. Their maximum values were recorded in the water area near the village Chervona Sloboda. An impact of a temperature factor and a number of other abiotic factors leads to intensive water «bloom» and subsequent mass extinction of algae Cyanophyta. Hot sunny days with the air temperature up to 18-32°C and water of temperature 21.0–25.8°C are most dangerous. As a result of lethal consequences, significant amounts of the most sensitive species of aquatic living organisms fall out of the ecosystem: Noble ?rayfish (Astacus astacus), Zander (Sander lucioperca). The presented data reflect the process of global warming. Keywords: Temperature; Ecological conditions; Aquatic organisms; Kremenchug Reservoir References Bat-oyun Tserenpurev, Masato, S., Mitsuru, T. (2012). Effects of cloud, atmospheric water vapor, and dust on photosynthetically active radiation and total solar radiation in a Mongolian grassland. Journal of Arid Land, 4(4), 349-356. Doi: 10.3724/SP.J.1227.2012.00349. Birungi, Z., Masola, B., Zaranyika, M.F., Naigaga, I. & Marshall, B. (2007). Active biomonitoring of trace heavy metals using fish (Oreochromis niloticus) as bioindicator species. The case of Nakivubo wetland along Lake Victoria. Physics and Chemistry of the Earth, Parts A/B/C, 32(15–18), 1350–1358. Doi: http://dx.doi.org/10.1016/j.pce.2007.07.034 Crayfish and fish die en masse in the Dnieper in Cherkasy region. (2016). TV channel VIKKA-news. News archive. 8 August, 16-46. EU Water Framework Directive (2010). DIRECTIVE 2000/60/EC OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 23 October 2000 establishing a framework for Community action in the field of water policy. Gorbunova, Z.N., Medved', V.A., & Borisova, Ye.V. (2001). Transformation of urea during the growth of some blue-green (Cyanoprocaryota) and green (Chlorophyta, Chlorococcales) algae. International Journal on Algae, 3(4). Krishnamurthy, T., Carmichael, W.W. & Sarver, E.W. (1986). Toxic peptides from freshwater cyanobacteria (blue-green algae). I. Isolation, purification and characterization of peptides from Microcystis aeruginosa and Anabaena flos-aquae. Toxicon, 24(9), 865-73. doi: 10.1016/0041-0101(86)90087-5. Kruzhilina, S.V. (2010). Perennial dynamics of quantitative development of phytoplankton of Kremenchug reservoir and its structural indicators. Rybogospodarska nauka Ukrainy, 3, 14-19. Likhareva, E.I. (1989). Possibilities of restoring crayfish stocks in water bodies of the Leningrad Region 1. Elements of crayfish biology. Collected papaers of the State Research Institute of Lake and River Fisheries, 300, 10. Lopes, I., Baird, D.J., & Ribeiro, R. (2006). Genetic adaptation to metal stress by natural populations of Daphnia longispina. Ecotoxicology and Environmental Safety, 63(2), 275–285. Doi: http://dx.doi.org/10.1016/j.ecoenv.2004.12.015 Results of the analysis of water samples of the Kremenchug reservoir in 3rd quarter of 2012. (2012) Cherkasy. Official portal of the city council. October 26. Romanenko, V.D. (2006). Methods of hydroecological research of surface waters. Kyiv: L?g?s. Sirenko, L.A. & Kirpenko, Yu.A., (2000). Biologically Active Metabolites of Blue-Green Algae and Their Role in Epidemiology. Hydrobiological Journal, 36 (5), 14. Doi: 10.1615/HydrobJ.v36.i5.110

New records of some phytoplankton for Bangladesh: Class - Chlorophyceae

The paper records 6 species of phytoplankton under the class Chlorophyceae namely, Pteromonas golenkiniana Pascher belonging to Family Phacotaceae; Pediastrum biradiatum var. biradiatum Meyen.belonging to Family Hydrodictyaceae; Scenedesmus alternas var. indicus Hortob. and Scenedesmus quadricauda var. inermis Playfair belonging to Family Scenedesmaceae ; Teilingia excavata (Rafls) Bourelly and Cosmarium vexatum W. West var. vexatum W. West belonging to Family Desmidaceae from Sylhet Division of Bangladesh which are all new records for Bangladesh.
 Bangladesh J. Plant Taxon. 27(1): 79-83, 2020 (June)

Comparative characterization of bacterial communities in digestive glands of Crassostrea gigas fed with different microalgal diets

The digestive glands of marine molluscs are colonized by a large number of microorganisms, and the structure and function of bacterial community could be severely affected by diets. Microalgae is the main food and energy sources for bivalves, while the impact of phytoplankton composition on the bacterial community as well as the health of bivalves are still not well understood. In the present study, the bacterial communities in digestive glands of oyster Crassostrea gigas fed with different diets were compared based on the high-throughput sequencing of partial 16S rRNA gene. There were significant differences of bacterial composition rather than diversity in digestive glands between the oysters fed with diatom dominant diet (Group N, mainly made up of Nitzschia closterium f.minutissima) and dinoflagellate dominant diet (Group P, mainly made up of Prorocentrum micans). The abundances of Prevotella, Vibronaceae, Ruminococcaceae, and Polaribacter were significantly higher in Group N (p < 0.05), and the abundances of Streptophyta and Acidimicrobiales were significantly higher in Group P (p < 0.05). According to the functional prediction results, the bacterial community in Group P displayed weaker capacities of Kdo2-lipid A biosynthesis as well as taurine degradation, and a stronger capacity of glycolysis compared with the bacterial community in Group N. The higher phylogenetic clustering degree of the bacterial community in Group P (p < 0.05) indicated the higher host selectivity on bacteria. These results suggested that the change of phytoplankton composition of diet would have large effects on bacterial communities in oyster digestive glands. The bacterial community in digestive glands of oysters living in dinoflagellate dominant waters would produce harmful impact to hosts. The present study provided a new perspective to explore the potential mechanism for the massive mortalities of oysters.

Количественная связь интенсивности солнечной радиации и среднесуточной величины насыщения фотосинтеза фитопланктона по свету для глубоководной части Чёрного моря

По данным экспедиционных исследований, проведённых в Чёрном море в 1987–1993 гг., установлена линейная зависимость между плотностью светового потока, достигающего поверхности моря (E0), и началом светового насыщения фотосинтеза фитопланктона (En opt). Для расчётов использованы измерения скорости фотосинтеза фитопланктона, полученные радиоуглеродным методом. Уравнение связи между указанными величинами представлено впервые для Чёрного моря. En opt — среднесуточная, оптимальная величина насыщения фотосинтеза по свету. Параметры кривой фотосинтез — свет, определяемые в короткопериодных экспозициях при постоянном освещении, отличаются от параметров, полученных в длительных опытах в условиях переменного освещения. Это обусловлено разным действием интенсивности и дозы облучения на скорость фотосинтеза фитопланктона. Величины фотосинтетических параметров за определённое время интегрируются в единственное значение, которое является оптимумом за весь наблюдаемый период. В работе проведена аппроксимация интегрированных суточных данных отдельно за сезоны и в целом за 1987–1993 гг. С помощью статистической обработки данных среднесуточных значений интенсивности солнечной радиации, падающей на поверхность моря, тангенса угла наклона кривой фотосинтез — свет и величины максимальной скорости фотосинтеза определена аппроксимация для функциональной зависимости En opt от E0. Уравнение с высокой достоверностью описывает изменение среднесуточной величины светового насыщения фотосинтеза в Чёрном море в различные сезоны года, оно применимо в диапазоне освещённостей от 3 до 75 моль квантов·м−2·сут−1. Эта зависимость включает легко доступный для измерения параметр и может использоваться при анализе физиологических характеристик фитопланктона и расчёте интегральной продуктивности фитопланктона в эвфотическом слое как по спутниковым наблюдениям, так и по экспедиционным данным.

Avaliação de nutriente limitante da produção algal em reservatórios do semiárido brasileiro

A sobrecarga de nutrientes em reservatórios artificiais pode representar um risco para a saúde humana e para a biodiversidade aquática. Assim, o estado trófico de um reservatório é uma característica importante para o entendimento das suas condições ambientais e seus possíveis usos. Sua descrição pode ser feita com base na concentração de nutrientes, principalmente o fósforo. Dessa forma, este trabalho testou a hipótese de que o fósforo total é o nutriente limitante do crescimento fitoplanctônico em reservatórios do semiárido brasileiro. Três modelos empíricos foram utilizados para inferir o status de nutriente limitante. Além disso, uma análise de regressão linear múltipla foi utilizada para estabelecer a relação de causalidade entre nutrientes (nitrogênio total — NT e fósforo total — PT) e a produção algal. Os resultados não confirmaram a hipótese. Conforme dois modelos utilizados, o NT foi o fator preponderante para a produção algal em cerca de 60% dos reservatórios, fato também observado na análise de regressão linear. Segundo o critério de Carlson, a herbivoria pode ser um importante fator do desenvolvimento algal. Assim, nossos resultados mostraram que a eutrofização por ambos os nutrientes, relevantemente o NT, e a herbivoria merecem ser considerados.

Larval Performance of Amphidromous and Landlocked Atyid Shrimp Species in the Genus Paratya under Different Feeding Conditions.

Freshwater shrimps in the family Atyidae exhibit two life history traits: 1) amphidromy, with many small embryos hatching into planktotrophic larvae that develop in the sea, and 2) landlocked, with few large embryos hatching into non-feeding lecithotrophic larvae, or facultative lecithotrophic larvae that develop in freshwater. The lecithotrophy of larvae is considered an adaptation to limited food conditions in the freshwater environment. Furthermore, faster development and settlement behaviours that large larvae exhibit are considered adaptations that allow the larvae to stay in or near parental habitats in fast-flowing streams. We therefore hypothesized that the facultative lecithotrophic larvae of landlocked shrimps might better adapt to limited food conditions as their large body size develops, an adaptation to maintain habitat position in flowing streams, than do planktotrophic larvae of companion amphidromous species developing in the sea. To test this hypothesis, we compared the larval feeding habits and size of two closely related species in the genus Paratya: the amphidromous P. compressa, with planktotrophic larvae, and the landlocked P. improvisa, with facultative lecithotrophic larvae. Larvae were reared by being fed commercially preserved or cultured phytoplankton (Tetraselmis sp.) and cultured zooplankton rotifers. Paratya compressa larvae did not survive, but P. improvisa larvae did develop into the juvenile stage under poor feeding conditions with preserved Tetraselmis alone, supporting our hypothesis of the effects of different larval feeding habits in amphidromous and landlocked atyid shrimp species. Hatchlings were larger and larval duration was shorter in P. improvisa than in P. compressa. Paratya improvisa larvae exhibited settlement behaviour beginning with the early zoeal stage. Our results also highlighted the retention strategy by which landlocked P. improvisa larvae stay in or near parental habitats.

Новые и редкие виды водорослей в планктоне нижнего течения реки Иртыш

По данным исследований фитопланктона нижнего течения р. Иртыш (от Тобольска до Ханты-Мансийска) в августе 2017 г. составлен таксономический список водорослей из 259 видовых и внутривидовых таксонов (ввт), включая номенклатурный тип вида. По сравнению с предыдущими исследованиями середины ХХ–начала ХХI вв. установлено возрастание видового богатства эвгленовых, динофитовых и хризофитовых водорослей. Выделено 115 новых для указанного участка реки ввт, среди которых преобладают Chlorophyta (60 ввт)и Euglenophyta (27 ввт). Отмеченные изменения свидетельствуют о распространении процесса антропогенногоэвтрофирования со среднего на нижнее течение р. Иртыш и возрастании загрязнения его вод органическими веществами.

Commentary: Multicellular Features of Phytoplankton

Commentary: Multicellular Features of Phytoplankton

Nitrogen uptake kinetics by phytoplankton in Meiliang Bay of Lake Taihu using &lt;sup&gt;15&lt;/sup&gt;N-tracer technology

浮游植物对氮的吸收与其生长繁殖密切相关，太湖梅梁湾湖区蓝藻水华频频暴发，对该水域浮游植物氮吸收进行研究具有重要意义.本文分别在冬、春、夏、秋4个季节于梅梁湾采样，对水体常规理化指标和浮游植物群落结构进行分析，并利用15N稳定同位素示踪技术研究了浮游植物对铵态氮（NH4+-N）、硝态氮（NO3--N）和尿素态氮（Urea-N）吸收的动力学特征.结果表明，太湖梅梁湾浮游植物群落除了秋季对NH4+-N的吸收不符合米氏方程外，其余均符合.冬季和春季3种形态氮最大吸收速率（Vmax）的大小依次为：NH4+-N > NO3--N > Urea-N，而夏季为：NH4+-N > Urea-N > NO3--N.3种形态氮Vmax的季节变化规律为夏季>秋季>春季>冬季.Vmax在不同季节以及不同形态氮之间的差异性可能与浮游植物群落组成以及水体中NH4+-N浓度不同有关.浮游植物对NH4+-N吸收的KS值在冬、春季高于夏季，对Urea-N吸收的Ks值则在夏、秋季高于冬、春季，而对NO3--N吸收的Ks值则在夏季显著高于其他3个季节.冬季和春季梅梁湾浮游植物群落最容易受到NO3--N限制，而最不容易受到Urea-N的限制；而夏季，则最容易受到NO3--N限制，而最不容易受到NH4+-N的限制，且浮游植物群落对NH4+-N的亲和力最高.与NO3--N相比，秋季浮游植物更容易受到Urea-N的限制.不同季节，容易对浮游植物产生限制作用的氮的形态不同.

Phytoplankton Ecology During a Spring-Neap Tidal Cycle in the Southern Tidal Front of San Jorge Gulf, Patagonia

Fil: Flores Melo, Elizabeth Ximena. Consejo Nacional de Investigaciones Cientificas y Tecnicas; Argentina. Institut des Sciences de la Mer de Rimouski; Canada

Selecting an HPLC method for chemotaxonomic analysis of phytoplankton community in Mediterranean coastal lagoons

1 - Phytoplankton observations are commonly used to contribute to the assessment of aquatic ecosystem health and their trophic status. Compared to other methods, chemotaxonomic analysis based on High Pressure Liquid Chromatography (HPLC) presents many advantages (e.g., rapidity, reproducibility, and capacity to include pigments from all cell sizes), but its use in coastal lagoons studies is still not very common. The method of Wright et al., (1991) recommended by the UNESCO (Jeffrey et al., 1997) and most frequently used for phytoplankton analysis in coastal lagoons, so far, was selected and compared to the more novel method of Hagerthey et al. (2006). 2 - The two methods that differed slightly with respect to their solvent gradients during chromatography (mobile phase) and column (stationary phase), were tested using a pigment mix from DHI Water and Environment comprising 30 different pigments. Extraction methods were tested using replicates of 1l of sub-surface water from the Thau lagoon (South of France), sampled in June 2013. Optimization of the extraction was performed by testing different volumes of solvent (2 to 5 ml), different solvents based on a mix of methanol, acetone, dimethylformamide, water, compared to acetone 90% and pure methanol, as well as different extraction times (10 min to 2 h), and the addition of the ion-pairing agent tetrabutyl ammonium acetate hydroxide (TBAA). 3 - The second method of analysis allowed better separation and resolution of most of the pigments, especially of lutein and zeaxanthin. The early-eluting most polar pigments and the more hydrophobic pigments eluting in the end of the chromatogram (chlorophylls and carotenoids) showed also better separation and peak shapes. 5 mL of the mix of acetone/ methanol/ water (45:45:10) allowed the best extraction of the pigments. The use of TBAA showed negative effects. 4 - For pigment analysis in coastal lagoon, our final protocol used 1 h extraction with 5 mL of acetone/ methanol/ water, and analysis with the gradient from Hagerthey et al. (2006). On our analytical equipment it needed some adjustments. It uses a longer chromatography run and quantified the phytoplankton pigment markers better than the method of Wright et al. (1991).

Evaluación del fitoplancton y la calidad del agua de un arroyo subtropical del Noroeste Argentino

El arroyo Calimayo pertenece a la cuenca del río Salí, principal red fluvial de la región. Este sistema lótico fue conocido por su gran diversidad biológica. Debido a la instalación de una papelera y sus efluentes las condiciones ecológicas se modificaron. El objetivo fue analizar el fitoplancton y la calidad del agua del arroyo Calimayo. Se realizaron muestreos estacionales desde invierno/2012 hasta otoño/2013 en tres sitios (S1: tramo alto, S2 y S3: sectores medio y bajo, respectivamente). Se recolectaron muestras ambientales y biológicas según metodología convencional. Los mayores registros de temperatura, pH y conductividad eléctrica se presentaron en S2 y S3. El S1 tuvo los máximos valores de oxígeno disuelto y la menor demanda bioquímica de oxígeno. Las diatomeas sobresalieron tanto cuali como cuantitativamente del resto de los grupos algales. El análisis de redundancia (RDA) permitió diferenciar dos grupos fitoplanctónicos en relación a variables abióticas. El S1 estuvo influenciado por estacionalidad, litología y fisicoquímica del agua, denotando un buen estado ecológico. En S2-S3 las condiciones ecológicas se vieron afectadas por el estado trófico del agua y los efluentes polutos, por lo que la calidad del agua y el fitoplancton se vieron notoriamente deteriorados. La ficoflora resultó ser un buen indicador de las condiciones ecológicas de este sistema lótico. Podemos afirmar que las condiciones limnológicas de este arroyo desde la década del 90 hasta la actualidad, fueron degradándose por la presencia de los efluentes industriales