Analysis Of Chlorophyll-a Research Articles

A Study of the Analysis of Chlorophyll-a Phytoplankton in the Tigris Rivers for Some Regions of Iraq by Using GIS Techniques

In this study, the distribution of chlorophyll-a for phytoplankton was monitored using Geographic Information System (GIS) techniques in selected regions of Iraq represented by the three governorates namely: Salah al-Din (Samarra (1), Baghdad (Al-Muthanna Bridge (2), Al-Utaifi (3), Al-Jadiriya(4), Kut (Al-Aziziyah (5), Al-Zubaydah (6), Al-Numaniyah (7), and Al-Muftah (8)) as human agricultural, and industrial activity rose in these locations. These stations, which are located along the Tigris River, were used as sites for collecting samples. The selection procedure was conducted on a monthly basis between February 2022 and January 2023. Chlorophyll-a measurements for phytoplankton throughout the sampling period varied from 3.7 to 2.59 g/L at stations. The two stations (Al-Utaifi and Al-Zubaydah) had similar values for both seasons, and the five stations in the dry season had values of less than 0.23 g/L. While phytoplankton numbers varied from 40.32 104 to 21.16 104cell/L for stations 3 and 5, respectively, they varied from 72.39 104 to 37.7 104cell/L for stations 6 and 8, respectively, throughout the wet season. In all of the stations and classes of phytoplankton, the amount of chlorophyll dye was approximately equal to the overall density of phytoplankton. The area under study’s predictive maps of chlorophyll-a analysis also revealed changes in the concentration of dye in all stations.

Evolution of Great Salt Lake’s Exposed Lakebed (1984-2023)

The Great Salt Lake has been rapidly shrinking since the highstand of the mid-1980s, creating cause for concern in recent decades as the lake has reached historic lows. Many investigators have assessed the evolution of lake elevation, geochemistry, anthropogenic impacts, and links to climate and atmospheric processes; however, the use of remote sensing to study the evolution of the lake has been significantly limited. Harnessing recent advancements in cloud-processing, specifically Google Earth Engine cloud computing, this study utilizes over 600 Landsat TM/OLI and Sentinel MSI satellite images from 1984-2023 to present time-series analyses of remotely sensed Great Salt Lake water area, exposed lakebed area, surface cover types, and chlorophyll-a analyses paired with modelled estimates for water and exposed lakebed area. Results show that a analyses paired with modelled estimates for water and exposed lakebed area. Results show that area has increased to ~3,500 km2 from ~500 km2. The area of unconsolidated sediments not protected by vegetation or halite crusts has risen to ~2,400 km2. Significant halite crusts are observed in the North Arm, having a max extent of ~150 km2 between 2002 and 2003, while only small extents of halite crusts are observed for the South Arm. Vegetation is more prevalent in the Bear River Bay and South Arm, with surface area increases over 400% since 1990. Gypsum is widely observed independent of halite crusts. The results highlight multiple instances of land-use/water-management that led to observable changes in water/exposed lakebed area and halite crust extent. This study demonstrates the important benefits of maintaining a lake elevation above ~4,194 ft to maximize lake and halite crust area, which would help mitigate possible dust events and maintain a broad lake extent.

Analysis of chlorophyll-a, sea surface temperature, and sea surface salinity in the Bay of Bengal

The waters of the Bay of Bengal (BoB) are influenced by the northeast monsoon (November-February) and the southwest monsoon (June-September). This study aims to determine the relationship between sea surface temperature (SST), sea surface salinity (SSS), and chlorophyll-a (Chl-a) during January 2021 in the BoB. The method used in this study is the method of correlation analysis, hypothesis testing, and analysis of variance using monthly average data for January 2021. The data comes from the Copernicus Marine Environment Monitoring Service (CMEMS) portal. Our analysis showed that high Chl-a was inversely related to low SST and SSS conditions and vice versa. This finding confirms the results of other previous studies. Medium and negative correlations occurred for the Chl-a - SST and Chl-a - SSS pairs. Meanwhile, the SST- SSS pair shows a strong and positive correlation. The hypothesis test shows that the conclusions drawn from these correlation relationships are acceptable. Furthermore, from the analysis of variance obtained, it was found that Chl-a had a significant effect on variations in SST and SSS, while SST had a significant effect on variations in SSS.

Monitoring of Lake Water Quality Through Streamlit Web Application (Case Study: Lake Matano And Lake Towuti, South Sulawesi)

The Indonesian government, through the National Medium Term Development Plan (RPJMN) 2015-2019, stated that water reservation, including the function of lakes, is one of the priorities. Lakes are not only functioned to maintain the ecological balance but also to provide water, protein, mineral, energy sources, and even tourism to support the community's economic growth. Lake Matano and Lake Towuti are designated as Nature Tourism Park areas. However, the lakes' environment is starting to be damaged. The damages exist in areas such as water-absorbent areas, lake borders, and lake waters. In addition, these damages increase the disaster risk. Therefore, to maintain the lake's sustainability, it is necessary to conduct research on the parameters of the condition of the fertility level of the lake waters. One of the parameters of the fertility level of the waters is chlorophyll-a . In the previous studies, observations of chlorophyll-a in Lake Matano and Lake Towuti have been carried out using Landsat-8. However, with these observations, a chlorophyll-a had not properly been monitored by using an application through web-based satellite imagery using web applications using the primary python programming language. The data for processing chlorophyll-a itself are obtained through the geemap library. Chlorophyll-a itself was processed using the existing algorithm. The current web application displays several features, namely the web application information and the results of the chlorophyll-a map. The results of the estimated value of chlorophyll-a range from 0 - 0.6 mg/m 3 . The minimum value of chlorophyll-a was found in 2014 which was 0.4 mg/m 3 , while the highest value of chlorophyll-a was found at 0.6 mg/m 3 in 2016. The results of this chlorophyll-a analysis was categorized into oligotrophic waters with low fertility.

High-frequency monitoring through in-situ fluorometric sensors: A supporting tool to long-term ecological research on lakes

Lake Maggiore is a site of the Long-Term Ecosystem Research (LTER) network, belonging to the deep subalpine Lake District in Northern Italy. Studies on the physical, chemical, and biological features of the lake have been performed continuously since the 1980s. The lake recovered from eutrophication reaching the present oligotrophic condition. In the last decade, climate change represents the main driving factor for the long-term evolution of the lake, affecting its hydrodynamics, nutrient status, and biological communities. In 2020 a high-frequency monitoring (HFM) system was deployed, with the aim to integrate long-term monitoring based on discrete sampling and analysis. The system consists of a buoy equipped with sensors for limnological variables and algal pigments. The high-frequency monitoring program is part of a cross-border project between Italy and Switzerland focusing on lake quality monitoring as a critical input for successful lake management. In this paper we focus on Chlorophyll-a data, with the aim to test whether in-situ fluorescence measurements may provide a reliable estimate of lake phytoplankton biovolume and its seasonal dynamic. Sensor’s performance was regularly tested comparing chlorophyll-a data taken by the in-situ fluorescent sensors (Cyclops7, Turner Design), data from laboratory fluorescence analysis (FluoroProbe, BBE Moldaenke), values obtained from chlorophyll-a analysis by UV-VIS spectrophotometry and data from phytoplankton microscopy analysis. We found a general good agreement between the Chlorophyll-a data obtained with the different methods, confirming the use of in-situ sensors as a reliable approach to measure algal pigments, especially to assess their variability in the short-term, but also to describe the seasonal pattern of phytoplankton biovolume. However, phytoplankton community composition played a substantial role in the performance of the different methods and in the reliability of in-situ data as a tool to assess algal biovolume. This study demonstrates that high-frequency monitoring (HFM), used in conjunction with discrete chemical and biological monitoring, represents an important advance and support in the long-term monitoring of freshwaters and is a useful tool to detect ecological changes. Regular checking and validation of the sensor readings through laboratory analyses are important to get trustworthy data.

Hyperspectral Core-Logging for Past Primary Productivity Assessment

Past primary productivity is tracked in lake sediments to reconstruct environmental changes. However, the resolution of the routinely used destructive techniques is not suitable for the analysis of a large number of samples due to cost. Non-destructive analysis of chlorophyll-a performed by hyperspectral imagery enables the quick determination of indices of past primary productivity. Eighteen indices used in paleo-environmental reconstruction were inventoried to define the best index capable of tracking chlorophyll-a by this technique. All the indices were applied to hyperspectral data measured on the sediment of Lake Bresson, in which detrital organic matter input is likely to skew chlorophyll-a identification, and the results were compared with concentrations measured by a routinely used destructive analysis. The 18 indices all produced a different result and only three indices were positively correlated with chlorophyll-a concentrations (n = 28, p < 0.0001). The detrital organic matter impacts chlorophyll-a characterization and shows the bias produced by the sediment matrix variations. Moreover, artificial modification of the sediment matrix revealed an impact of the mineral phase. To tackle this issue, the indices are normalized by two proxies of the sediment components. This new approach reduces the impact of detrital organic matter, hence the sediment matrix variations also reduce the normalization of the chlorophyll-a indices by a specific proxy of the mineral phase. These results identify the impact of local geochemical features that limit past primary productivity assessment and show the necessity of characterizing the sediment composition prior to tracking the chlorophyll-a by hyperspectral imaging.

Trophic status analysis and estimation of fish production in Aneuk Laot Lake aquatic resources management, Sabang City

Aneuk Laot Lake is located in Sabang City, Weh Island, Aceh Province. Changes in water quality can affect the life of aquatic organisms found in Aneuk Laot Lake. The purpose of this research estimates fish production and trophic status for the aquatic resource management of Aneuk Laot Lake, Sabang. This research was conducted in September 2019 in Lake Aneuk Laot using the TRIX, TSI (Trophic State Index) and Nygaard index methods to determine fish production and trophic status. Observation stations were determined using stratified random sampling method and analysis of chlorophyll-a was done using the Trichomatic method. The results showed that the waters of Aneuk Laot Lake can be categorized as eutrophic to hypereutrophic. The estimated value of fish production in Aneuk Laot Lake based on the chlorophyll-a approach is 109.84 kg/ha/year, with a lake area of 61.6 ha. Water quality parameters are still in a state that can be tolerated by aquatic organisms in Aneuk Laot Lake.Keywords:Fish production potential Water qualityTRIX indexBiomass productionWater productivity

Effect of Ultraviolet-C Radiation on the Morphology of Cyanobacteria Nostoc sp. LBALBR-2 Isolated from Supply Reservoir (Belém, Pará, Brazil)

Cyanobacteria are photosynthetic prokaryotic organisms that in aquatic environments can compose the phytoplankton and phytobenthos, being important in the primary production of these ecosystems. The objective of this work was to identify the main morphological variations of the cells, filaments and thallus of the cyanobacteria Nostoc sp. LBALBR-2 submitted to ultraviolet radiation (UV-C) in microcosm systems. The cyanobacteria Nostoc sp. was subjected to four treatments: 1- control treatment in nutrient medium; 2- treatment in nutrient medium with exposure to UV-C radiation; 3- control treatment in medium without nutrients and 4- treatment in medium without nutrients with exposure to UV-C radiation. Optical density and chlorophyll-a analyses were performed to determine the growth of Nostoc populations and microscopic analyses to characterize the morphological development of the species. Lack of nutrients generated short trichomes with terminal heterocytes, scattered solitary akinetes and appearance of hormogonia. On nutrient medium the trichomes of Nostoc sp. showed predominantly the vegetative serial form. Cultures exposed to UV-C produced anomalous cells, thick mucilage, fragmented trichomes and hormogonia. It is concluded that Nostoc sp. LBALBR-2 grew well under eutrophication conditions and although it showed cell deformation it was resistant to UV-C radiation.

The microalgae Chaetoceros tenuissimus exposed to contaminants of emerging concern: A potential alternative to standardized species for marine quality assessment

Microalgae occupy a key trophic level since primary producers at the base of the aquatic food chain. Moreover, they are well suited for ecotoxicological tests because easily cultured and sensitive to contaminants. However, species sensitiveness to the same chemicals can vary greatly. Thus, we characterized the non-standardized diatom Chaetoceros tenuissimus by means of growth inhibition, biochemical, and infrared-spectroscopy (FT-IR) tests and compared the results against the standardized diatom Phaeodactylum tricornutum. The two species were exposed for 72 h to four chemicals: nanoparticles (n-TiO2, n-ZnO), potassium dichromate (K2Cr2O7), and surfactant (polyethylene glycol; PEG). The sensitivity of C. tenuissimus in the growth inhibition test and the chlorophyll-a analysis was always higher than P. tricornutum. In particular, the chlorophyll-a analysis exhibited an earlier endpoint for C. tenuissimus exposed to all chemicals here considered. FT-IR showed spectral alterations (molecular changes in chlorophyll) in both microalgal species exposed to the chemicals compared to the negative controls, with stronger alterations in C. tenuissimus than P. tricornutum. In conclusion, C. tenuissimus showed higher sensitivity to a broad range of toxic chemicals, indicating the potential use of this species in marine quality assessment as an alternative to the standardized P. tricornutum.

미세기포를 이용한 Chlorella sp. 제거에 관한 연구

This study carried out zeta potential measurements of Chlorella sp. under various solution conditions and investigated its characteristics through implementation of size control of the microbubbles in order to eliminate algae whichis problematic for both aquatic ecosystems and human activities. The DAF process was adopted and several coagulants were used to remove the Chlorella sp. A CCD Camera was used to measure and analyze the sizes of the microbubbles, and a fluorescent microscope was used to observe particles, algae species, and the community as a whole. Zeta potential behavior of the algae was analyzed using ELS-Z. Both lab-scale and pilot-scale experiments were conducted to test the flotation process. Polyaluminium chloride(PAC) coagulant was used, and the removal efficiency of the algae was assessed through chlorophyll-a analysis. In the lab-scale experiment, 2.2 mg/L, 11 mg/L, 22 mg/L, and 44 mg/L of polyaluminium chloride were injected to coagulate the algae. The microbubbles, whichwere generated at an air pressure of 450-550 kPa, caused the coagulated algae to float. The microbubble size was controlled at 36 ㎛, 100 ㎛, and 200 ㎛ by using different diffusers. The results of the lab-scale experiments on the flotation plant indicated that the average removal rate was about 90% or above for 11 mg/L, 22 mg/L, and 44 mg/L of polyaluminium chloride. On the other hand, in the pilot-scale experiment, the removal efficiency was 85%-95% in all dose ranges of polyalumium chloride and aluminium sulfate coagulants.

The Influence of Chlorpyrifos on the Nonenzymatic Antioxidants Content in Macrophytes Leaves.

Water pollution can be moved or limited by macrophytes in a phytoremediation process. The presence of insecticides in the plant life environment may affect physiological processes and contribute to the formation of secondary oxidative stress in plant tissues. To protect against oxidative stress, macrophytes have developed a system of mechanisms consisting of nonenzymatic and enzymatic antioxidants. The influence of various concentrations of chlorpyrifos on the nonenzymatic system in Canadian waterweed (Elodea canadensis Michx.), needle spikerush (Eleocharis acicularis) and water mint (Mentha aquatica L.) was studied. The differences in the value of the total concentration of polyphenols and flavonoids, as well as analysis of chlorophyll-a, chlorophyll-b, anthocyanin and carotenoid concentrations were determined in leaves. Research indicated a significant increase in the content of polyphenols and flavonoids in a solution with the highest concentration of chlorpyrifos while the opposite tendency was observed after analyses of the main assimilating pigments of plant tissues. It was concluded that aqueous plants exposed to toxic insecticide molecules created a defensive mechanism by nonenzymatic antioxidant systems and the amount of low-molecular weight compounds depended on the pollutant concentration which influenced biosynthesis mechanisms in plant cells.

Community structure of plankton in Aneuk Laot Lake Sabang Pulau Weh

The role of plankton as natural food affects the potential of fish in the waters. The structure of the plankton community in the Aneuk Laot Lake can provide an overview of the stability of these waters. This study aims to determine the plankton biomass and the structure of the plankton community of Aneuk Laot Lake Sabang. This research was conducted in September 2019 in the waters of Aneuk Laot Lake. Determination of observation stations using the stratified random sampling method, identification of plankton using the census method and analysis of chlorophyll-a using the Trichomatic method. The results showed that the plankton composition consisted of 27 phytoplankton and 4 zooplankton genera which were divided into Bacillarophyceae (36%), Chlorophyceae (19%), Cyanophyceae (16%), Zygnematophyceae (10%), Dinophyceae (3%), Euglenophyceae (3%) and Crustacean class (13%). The abundance of plankton was 21,333 ind/l, the most abundant type is Navicula sp. Diversity index value (2.97) is category high, eveness index (0.87) and low dominance index (0.07). Chlorophyll-a values ranged from 2.84 to 4.84 mg/l including the medium nutrient category. Aneuk Laot Lake has a high level of community stability with trophic status of mesotrophic-eutrophic.

Catching investigation of yellowfin tuna (Thunnus Albacares) based on the distribution of chlorophyll-a in the North Waters of Aceh: A November and December analysis

The purpose of this study was to analyze the distribution of chlorophyll-a on the catch of yellowfin tuna in the northern waters of Aceh. This research was conducted in the north of Aceh waters starting from November to December 2020. fish catch data was collected by direct survey in the field by following the activities of fishermen and recording the number of catches. Data on chlorophyll-a was obtained from Aqua Modis satellite imagery. The catch data analysis used the CPUE model, while the chlorophyll-a analysis was carried out using the SeaDas 7.5 and ArcGIS. The results showed that the catch of yellowfin tuna was higher in November than in December as well as the distribution of chlorophyll-a content. The coefficient of determination (Adjusted R Square) is 0.09, which means that the relationship between chlorophyll-a and yellowfin tuna catches is only 9%, while 91% is influenced by other factors. These results inform that the content of chlorophyll-a does not show a significant relationship to the catch of yellowfin tuna.

Monitoring Seawater Quality in the Kali Porong Estuary as an Area for Lapindo Mud Disposal leveraging Google Earth Engine

The hot mudflow released by Lapindo Mud Volcano periodically requires a large storage space. It is resulting the change in the main function of Kali Porong which is the channel for mud to the river mouth. This causes changes in water quality at Kali Porong estuary. The purpose of this study was to monitor water quality at Kali Porong estuary using Sentinel 2 image data with Total Suspended Solid (TSS) and chlorophyll-a analysis. Cloud computing technology can process image data into useful information. One of the open source cloud computing platforms is Google Earth Engine (GEE). In this platform, there is a database for storing satellite image data, including Sentinel-2. In addition to storing remote sensing data, GEE can process images quickly using the Java scripting language. In this study, monitoring was carried out in February-June 2021. The results show the average value of chlorophyll-a each month from February to June was 2.78 μg/m3, 2.76 μg/m3, 2.74 μg/m3, 2.98 μg/m3, and 3.2 mg/l. The average monthly TSS values from February to June were 16.11 μg/m3, 15.91 μg/m3, 15.76 μg/m3, 17.45 μg/m3, and 19.86 μg/m3, respectively. The correlation test result for chlorophyll-a estimation is 0.654. In the other hand, the correlation test result for the estimated TSS is 0.652. The trophic status of the waters at Kali Porong estuary is in the eutrophic class or has been polluted. The results show a tendency for the area with polluted trophic status to increase from February to June.

Analysis of primary productivity and trophic status of Kuala Gigieng waters Aceh Besar for sustainable fisheries management

Kuala Gigieng is one of the estuary areas in Aceh Besar Regency. This research is about the analysis of chlorophyll-a and trophic status of Kuala Gigieng waters in the context of sustainable fisheries management. This research was conducted in April 2019 in the water of Kuala Gigieng. This study aims to determine the trophic status of the waters, the value of chlorophyll-a and the abundance of phytoplankton in the Kuala Gigieng waters. Determination of observation stations using random stratified sampling method. Analysis of chlorophyll-a using the Trichomatic method. Analysis of the trophic status of the waters with the Trix method. The results showed that the waters of Kuala Gigieng were categorized as high fertility (eutrophic). The value of chlorophyll-a ranged from 0.21 u.g/l - 5.56 ug/l, and the value of net primary productivity (NPP) ranged from 3.47-27.77 mgC/m3/hour and the value of gross primary productivity (GPP) ranged from 5.20-32.98 mgC/m3/hour. Meanwhile, the abundance of plankton ranged from 133.33-207.40 ind/l. Water quality parameters are still suitable for the growth of plankton in Kuala Gigieng waters.

Remote Detection of Cyanobacterial Blooms and Chlorophyll-a Analysis in a Eutrophic Reservoir Using Sentinel-2

Harmful cyanobacterial blooms have been one of the most challenging ecological problems faced by freshwater bodies for more than a century. The use of satellite images as a tool to analyze these blooms is an innovative technology that will facilitate water governance and help develop measures to guarantee water security. To assess the viability of Sentinel-2 for identifying cyanobacterial blooms and chlorophyl-a, different bands of the Sentinel-2 satellite were considered, and those most consistent with cyanobacteria analysis were analyzed. This analysis was supplemented by an assessment of different indices and their respective correlations with the field data. The indices assessed were the following: Normalized Difference Water Index (NDWI), Normalized Differences Vegetation Index (NDVI), green Normalized Difference Vegetation Index (gNDVI), Normalized Soil Moisture Index (NSMI), and Toming’s Index. The green band (B3) obtained the best correlating results for both chlorophyll (R2 = 0.678) and cyanobacteria (R2 = 0.931). The study by bands of cyanobacteria composition can be a powerful tool for assessing the physiology of strains. NDWI gave an R2 value of 0.849 for the downstream point with the concentration of cyanobacteria. Toming’s Index obtained a high R2 of 0.859 with chlorophyll-a and 0.721 for the concentration of cyanobacteria. Notable differences in correlation for the upstream and downstream points were obtained with the indices. These results show that Sentinel-2 will be a valuable tool for lake monitoring and research, especially considering that the data will be routinely available for many years and the images will be frequent and free.

The estimation of mackerel tuna (Euthynnus affinis) fishing ground in Malacca Strait

In fishing activity, the success is indicated by the number of catches that extremely influenced by the conditions of fishing ground. Information of the potential fishing ground is needed for fishermen to increase the effectiveness and efficiency in fishing activity. Sea Surface Temperature (SST) and chlorophyll-a in waters are two things that can affect the potential of fishing ground. The research aims to create distribution map of SST and chlorophyll-a and to presume the potentials of fishing ground in Malacca Strait based on distribution of SST and chlorophyll-a in Malacca Strait (2015-2019). The data of SST and chlorophyll-a distribution in Malacca Strait were using Aqua MODIS satellite imagery. Based on the result of SST and chlorophyll-a analysis, potential fishing ground in Malacca Strait is expected located around East Aceh in Western season, Malaysian waters in the Transition I season, between Asahan and Malaysian waters in Eastern season and between Deli Serdang and East Aceh in the Transition II season.

DETERMINATION OF THE TROPICAL STATUS OF FLOATING NET CAGE WATER BASED ON THE DISTRIBUTION OF NITROGEN, PHOSPHORUS AND CHLOROPHYLL-A

The dominant source of pollutants for floating net cages are fish feed and feces. They cause phosphorus and nitrogen in water increase, trigger eutrophication, marked by the appearance of algae. Algae are green plants, contain chlorophyll-a. The content of phosphorus, nitrogen and chlorophyll-a can be used to determine the tropical status of water. The objective of this research is to determine the tropical status of marine cage water. The research method was descriptive laboratory. Nitrogen content is measured as nitrite according to SNI 6989.9-2004, nitrate according to APHA Section 4500-NO3, ammonia according to SNI 19-1655-1989. Phosphorus analysis according to SNI 06-6989-31: 2005. Chlorophyll-a analysis used the Strickland & Parson method by spectrophotometry. Laboratory data were analyzed for tropical status based on nitrogen, phosphorus and chlorophyll-a content. The results showed that the tropical status of the KJA water of Gajah Mungkur Reservoir Wonogiri in the rainy season had eutrophic status, containing high levels of phosphorus and nitrogen elements. The eutrophic status indicated that the water had been polluted by an enhancement of nitrogen levels by 18.345 µg/L and phosphorus by 420.65 µg/L. These nitrogen and phosphorus pollutants increased the growth of chlorophyll-a by 12.70 µg/L.

Spatial Distribution Of Chlorofil-a In Laguna Kabori Manokwari Regency

Kabori Lagoon is a lagoon located in Manokwari Regency, West Papua, where the water quality data is still very limited. Chlorophyll-a is the most important photosynthetic pigment for aquatic plants such as phytoplankton. The purpose of this study was to determine the horizontal distribution of chlorophyll-a based on the spatial data approach in the waters of the Kabori Lagoon. The study was conducted from April to May 2019. The sampling point was determined by purposive sampling at eight points for sampling of chlorophyll-a and water parameters including physics and chemistry (temperature, DO, salinity, brightness and depth). Measurement of physical and chemical parameters is carried out in situ. Chlorophyll-a analysis was carried out at the Laboratory of Water Productivity and Quality, Faculty of Marine and Fisheries Sciences, Hasanuddin University. Spatial data processing used ArcGIS 10.4 and Surfer 16 to create chlorophyll-a distribution maps and bathymetry. The results showed that the chlorophyll-a content in Observation I was in the range of 0.12-2.40 mg/m3 and in Observation II it was in the range of 1.43-10.84 mg/m3. Based on the chlorophyll-a content, the Kabori Lagoon is included in the mesotrophic category. Spatially, the distribution of chlorophyll-a content varies, but tends to be higher in the southern part of the lagoon than in the northern part of the lagoon.
 Spatial distribution, Chlorophyll-A, Kabori Lagoon, Mesotrophic

ESTRUCTURA Y DISTRIBUCIÓN DE LA COMUNIDAD FITOPLANCTÓNICA A LO LARGO DEL ESTRECHO DE GERLACHE DURANTE EL VERANO AUSTRAL 2018-2019

En el presente estudio se describe la estructura de la comunidad fitoplanctónica y su distribución en el Estrecho de Gerlache (EG) durante el verano austral 2018-2019. Se realizaron arrastres verticales de 200 m a la superficie a través de una red Bongo equipada con flujómetro. Las muestras se fijaron en Lugol básico en una relación 100:1. Muestras adicionales para el análisis de nutrientes y clorofila-a se tomaron a través de una roseta oceanográfica. Mediante un análisis de funciones empíricas ortogonales estandarizadas el Estrecho de Gerlache fue regionalizado en cuatro regiones, usando los datos de riqueza y químicos. De las regiones identificadas se ubicaron dos en el norte, una en el centro y otra en el sur. En términos de riqueza se identificaron 40 taxones representados por 28 diatomeas, 11 dinoflagelados y un silicoflagelado. La mayor riqueza y abundancia se encontró en la región central siendo las diatomeas el grupo dominante en todas las estaciones. Las especies Corethron criophilum y Porosira glacialis representaron el mayor aporte a la comunidad. Los dinoflagelados formaron el segundo grupo más distintivo en el área de estudio, representado por las especies Protoperidinium pyrum y Prorocentrum minimun. Por otra parte, los silicoflagelados con la especie Dictyocha sp. fue el grupo con menor representatividad en el área, sin embargo, su mayor abundancia se observó en la región norte. Se observaron diferencias en la estructura de la comunidad, con dominancia de las diatomeas sobre los demás grupos identificados; dichos cambios pueden obedecer a las técnicas analíticas empleadas y a la variabilidad interanual.