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Water pollution is a global environmental issue, and aquatic sediments are important compartments that might act as sinks or sources of contaminants. Once in the environment, inorganic contaminants such as metals can cause cytogenotoxic effects that damage genetic material and harm the aquatic community. Biological assays such as the Allium test can be used to investigate potential cytogenotoxicity of contaminated sediments based on the alterations of cell cycle indexes and chromosomal aberration frequencies. Therefore, we aimed to assess the toxicity of sediments from four Brazilian reservoirs using the Allium test. Sediments were sampled and elutriates were prepared in a simulating sediment resuspension in the water column. The Allium test was applied to the elutriates, and the metals copper, chromium, cadmium, lead, zinc, and iron were quantified. The elutriates derived from reservoir sediments were able to reduce the mitotic and anaphase index, increase the prophase and metaphase index, and boost chromosomal aberrations compared to the negative control. The cytogenotoxic effects observed may be linked to the presence of copper, zinc, and iron. Therefore, our results showed that the Allium test was a sensitive tool for warning the occurrence of genotoxic contaminants in sediment elutriates from four Brazilian reservoirs.

Cancer is the main cause of death in the world with the number of sufferers in 2008 as many as 12.7 million with a death rate of 7.6 million people. In Indonesia, it is estimated that there are more than 1 million cancer patients in 2010. One of the ways to prevent cancer is primary prevention by adjusting the pattern and type of food consumed. Functional food introduced by bioactive components from sea cucumbers is an alternative for cancer prevention. The specific objective of this research was to produce meat-based functional foods containing anti-cancer compounds derived from sea cucumbers that can prevent cancer. The preliminary tests conducted were the sea cucumber extract lethality test against Artemia salina, namely the Brine Shrimp Lethality Test (BSLT), and the total bacteria of beef meatballs. The results of the observation of the lathality of sea cucumber extract against Artemia salina and total bacteria of the meatball showed that the sea cucumber extract had high lathality against Artemia salina and was able to reduce the total bacteria in meatballs during storage period. The lathality of sea cucumber extract was strongly influenced or stimulated by heating treatment. Based on the BSLT test, of the five types of sea cucumbers, two of them (Holothuria similis and Pearsonothuria graeffei) have high lathality. Sea cucumber extract was also able to inhibit both bacterial and fungal growth in meatballs during storage at room temperature. Keywords: Beef Meatballs, Total Bacteria, Sea Cucumber, BSLT.

Freshwater-dominated estuaries experience large fluctuations in their physical and chemical environments which may influence larval dispersal, settlement, and connectivity of populations with pelagic larval stages. We used settlement patterns and natural tagging along with numerical hydrodynamic model results to assess settlement and connectivity among oysters across the freshwater-dominated Mobile Bay-eastern Mississippi Sound (MB-EMS) system. Specifically, we (1) tested how freshwater inputs and associated environmental attributes influenced settlement patterns during high and low discharge conditions in 2014 and 2016, respectively, and (2) analyzed trace element (TE) ratios incorporated into multiple shell types (larval and settled shell of spat and adult shells) to determine if shells collected in situ incorporate temporally stable site-specific signatures. We also assessed if TE ratios compared between adult (TE natal signature proxy) and larval shells could infer connectivity. Larval settlement was 4× higher during low discharge than during high discharge when oyster larvae only settled in higher salinity regions (EMS). Spat and adult shells incorporated site-specific TE ratios that varied from weeks to months. Connectivity results (May-June 2016 only) suggest that EMS is an important larval source to EMS and lower MB. While we were able to infer probable connectivity patterns using adult and larval shells, more study is needed to assess the utility of adult shells as proxies for natal-location TE signatures. Results provide a baseline for measuring future larval connectivity and adult distribution changes in the MB-EMS system. Biological and geochemical data demonstrate the potential to identify environmental attributes that spatiotemporally mediate settlement and connectivity in dynamic systems.

Enzyme-induced carbonate precipitation (EICP) is a bio-cementation technique and a sustainable method of ground improvement. This study examines the influence of the concentrations of substrates [S 0] and enzymes [E 0] as well as enzyme activity (A E) on the calcium carbonate (CaCO3) precipitation ratio (PR) using 130 test-tube experiments. It was found that the effect of enzyme concentration and activity on PR can be explained using a normalisation of [E s] = [E 0] × A E, where [E s] is the adjusted enzyme concentration. PR increased non-linearly with increasing [E s]/[S 0] and reached 100% at a threshold [E s]/[S 0] value of approximately 20 kU/mol. An exponential function was developed that could capture the relationship between PR and [E s]/[S 0] with reasonable accuracy. This observation was further evaluated with data from the literature consisting of a further 100 test-tube experiments. EICP solutions consisting of [E s]/[S 0] = 20 kU/mol were found to be optimum for soil treatment. The established function was later extended to predict strength gain as measured by the unconfined compressive strength (UCS) and the splitting tensile strength (STS) for EICP-treated soils and could predict the strength gain (UCS/STS) with reasonable accuracy. Results from scanning electron microscopy images, energy-dispersive X-ray spectroscopy and X-ray powder diffraction showed that the precipitated calcium carbonate in test tubes and treated soil was mostly calcite crystals with different morphologies, possibly due to the level of purity of the urease enzyme used.

Microplastics are plastic particles less than 5 mm in diameter. These plastics mostly result from degradation of larger plastics. Due to their small size, they are often accidentally ingested by sea faunas, particularly the deposit and filter feeders. However, information on the ingestion of microplastics by sea fauna such as jellyfish is rare. This paper provides evidence of ingestion of microplastics by jelly fishes (Crambionella orsini) along the Kenyan Coast. Samples were taken from three stations (Mikindani and Makupa in Mombasa, and Dabaso in Mida Creek) between 31st January 2018 and 3rd February 2018 using tow nets. Samples were digested using 10 % KOH at 60 °C for 24 hrs and sieved through a 38 µm sieve. Products below 38 µm were filtered using a 0.8 µm Whatman filters, then dried in an oven and viewed under a dissecting microscope for microplastics. Suspected microplastics were confirmed using a hot needle test. Microplastics obtained were mainly fibres of different colours: black, blue, green, colourless, purple, red and yellow. Colourless fibres were the majority accounting for 53 % of the total number of fibres while purple fibres were the least at only 1 %. Mean concentration of microplastics was highest in Dabaso (0.05 mp/g of tissue), whereas in Mikindani and Makupa were almost equal (i.e., 0.03 ± 0.003 mp/g in Mikindani, and 0.03 ± 0.01 mp/g in Makupa). Statistically, the means were not significantly different between the stations (F1, 2 = 1.34; P = 0.43). This study presents evidence of contamination of the Kenyan coastal waters by microplastics and their ingestion by sea fauna such as jellyfish. Results of this study will help reinforce the plastic ban in the country to prevent further accumulation in the environment.

Deep-sea Cibicidoides pachyderma (forma mundulus) and related Cibicidoides spp. were cultured at in situ pressure for 1–2 d, or 6 weeks to 3 months. During that period, fluorescence analyses following BCECF-AM (2′,7′-bis(2-carboxyethyl)-5-(and-6)-carboxyfluorescein acetoxymethyl ester) or calcein (bis[N,N-bis(carboxymethyl)aminomethyl]-fluorescein) labelling revealed a persisting cytoplasmic sheet or envelope surrounding the Cibicidoides tests. Thus, the Cibicidoides shell can be considered as an internal rather than an external cell structure. A couple of days to a week after being transferred into high-pressure aquaria and adjusted to a pressure of 115 bar, the foraminifera changed from a mobile to a more or less sessile living mode. During this quasi-sessile way of life, a series of comparably thick static ectoplasmic structures developed that were not resorbed or remodelled but, except for occasional further growth, remained unchanged throughout the experiments. Three different types of these permanent structures were observed. (a) Ectoplasmic “roots” were common in adult C. pachyderma, C. lobatulus, and C. wuellerstorfi specimens. In our experiments single ectoplasmic roots grew to a maximum of 700 times the individuals' shell diameter and were presumably used to anchor the specimen in an environment with strong currents. (b) Ectoplasmic “trees” describe rigid ectoplasmic structures directed into the aquarium's water body and were used by the foraminifera to climb up and down these ectoplasmic structures. Ectoplasmic trees have so far only been observed in C. pachyderma and enabled the tree-forming foraminifera to elevate itself above ground. (c) Ectoplasmic “twigs” were used to guide and hold the more delicate pseudopodial network when distributed into prevailing currents and were, in our experiments, also only developed in C. pachyderma specimens. Relocation of a specimen usually required it to tear apart and leave behind the rigid ectoplasmic structures and eventually also the envelope surrounding the test. Apparently, these rigid structures could not be resorbed or reused.

Cloudina is a globally distributed Ediacaran metazoan, with a tubular, funnel-in-funnel form built of thin laminae (ca. 1–10 μm). To what degree local environmental controlled morphology, and whether early diagenesis controlled the degree of calcification of Cloudina, is debated. Here we test these hypotheses by considering assemblages from four, coeval localities from the Upper Omkyk Member, Nama Group, Namibia, from inner ramp to mid-ramp reef across the Zaris Subbasin. We show that sinuosity of the Cloudina tube is variable between sites, as is the relative thickness of the tube wall, suggesting these features were environmentally controlled. Walls are thickest in high-energy reef settings, and thinnest in the low-energy, inner ramp. While local diagenesis controls preservation, all diagenetic expressions are consistent with the presence of weakly calcified, organic-rich laminae, and lamina thicknesses are broadly constant. Finally, internal ‘cements’ within Cloudina are found in all sites, and pre-date skeletal breakage, transport, as well as syn-sedimentary botryoidal cement precipitation. Best preservation shows these to be formed by fine, pseudomorphed aragonitic acicular crystals. Sr concentrations and Mg/Ca show no statistically significant differences between internal Cloudina cements and botryoidal cements, but we infer all internal cements to have precipitated when Cloudina was still in-situ and added considerable mechanical strength, but may have formed post-mortem or in abandoned parts of the skeleton.

Species of large, testate, rhizarian protists in the genus Gromia are often common in high-latitude coastal environments, including fjords, but are frequently overlooked and almost all are undescribed. Here, we describe three new gromiid species from the Nuuk fjord system on the west coast of southern Greenland. Morphologically, the new species differ in the size and shape of the test. Gromia cucumiformis sp. nov. is elongate, up to 5.5 mm long, with a length:width (L/W) ratio of 4.3–5.5; G. botelliformis sp. nov. is up to 2.1 mm long, with a L/W ratio of 3.0–4.8; G. brevis is typically less than 1.0 mm long, with a L/W ratio around 2.0. Genetically, they are well-characterised and split between two clades. Gromia cucumiformis and G. brevis branch with several species of deep-water gromiids from the Arabian Sea and the Weddell Sea, while G. botelliformis branches with deep Weddell Sea species and several unnamed and morphologically uncharacterised gromiids from different parts of the world. Gromia botelliformis and G. brevis are currently known only from the Nuuk fjords, but sequences of G. cucumiformis from Greenland group together with sequences from Svalbard and the White Sea. Our genetic data reveal four additional clades of undescribed Gromia species. Two contain sequences from Greenland, Svalbard and the White Sea, one comprises sequences from Greenland and the White Sea and one is limited to sequences from Greenland. These results demonstrate the high genetic diversity of gromiids and their widespread distribution in the coastal and deep-sea environments. Species of large, testate, rhizarian protists in the genus Gromia are often common in high-latitude coastal environments, including fjords, but are frequently overlooked and almost all are undescribed. Here, we describe three new gromiid spe- cies from the Nuuk fjord system on the west coast of southern Greenland. Morphologically, the new species differ in the size and shape of the test. Gromia cucumiformis sp. nov. is elongate, up to 5.5 mm long, with a length:width (L/W) ratio of 4.3–5.5; Gromia botelliformis sp. nov. is up to 2.1 mm long, with a L/W ratio of 3.0–4.8; Gromia brevis is typically less than 1.0 mm long, with a L/W ratio around 2.0. Genetically, they are well-characterised and split between two clades. Gromia cucumiformis and G. brevis branch with several species of deep-water gromiids from the Arabian Sea and the Weddell Sea, while G. botelliformis branches with deep Weddell Sea species and several unnamed and morphologically uncharacterised gromiids from different parts of the world. Gromia botelliformis and G. brevis are currently known only from the Nuuk fjords, but sequences of G. cucumiformis from Greenland group together with sequences from Svalbard and the White Sea. Our genetic data reveal four additional clades of undescribed Gromia species. One contains sequences from Greenland, Svalbard and the White Sea, two comprises sequence from Greenland and the White Sea and one is limited to sequences from Greenland. These results demonstrate the high genetic diversity of gromiids and their widespread distribution in Arctic as well as in deep-sea environments.

Highlight Light intensity from plastic waste was positively correlated with the abundance of zooxanthellae in corals. The abundance of zooxanthellae between sack plastic and clear plastic treatment tended to be the same. The treatment of packaging plastic was treated with the lowest light intensity. The treatment of black plastic was the treatment that produced the lowest abundance of zooxanthellae. Abstract Coral growth in Indonesia was being disrupted due to the continued threat of environmental change, such as littering to the beach. This study aimed to analyze the effect of the attachment of different colored plastic waste to the rate of zooxanthellae abundance on branching corals in Kelapa Dua Island waters. Branching coral colony samples consisted of the genus Acropora and Porites with a total of 15 fragments of coral colonies at the depth of 80-90 cm were tested with a treatment of the attachment plastic wastes (control, clear plastic, plastic sack, plastic packaging, and black plastic) for four days. The zooxanthellae abundance was calculated using the APHA (American Public Health Association) formula. The results of zooxanthellae abundance on the closure treatment of branching coral samples with black plastic and control had the lowest and highest values by 4.25 x 10 5 cells/cm 2 and 1.38 x 10 6 cells/cm 2 . The results of the linear regression test showed that there was a significant relationship between plastic waste with low light intensity and a decrease of zooxanthellae abundance in coral colonies with the equation Y of 972.78x + 653402, determination index (R2) of 0.68, and correlation index (r) of 0.83. These results indicated that the attachment of plastic waste to branching coral colonies could be a stressor on coral animals in reducing light intensity, which caused a reduction of zooxanthellae abundance as coral endosymbiont.

Introduction: Eucidaris thouarsii is a cidaroid sea urchin found from the Gulf of California to Ecuador. Its taxonomy is based on general descriptions of test shape, primary and secondary spines, the Aristotle’s lantern, apical system, and peristome. Objective: To redescribe E. thouarsii with detailed descriptions, adding new taxonomic characters. Methods: We examined and reidentified 792 specimens, measuring and analyzing in detail structures of taxonomic value. Results: The horizontal diameter of the test ranges from 2.8 to 48.45 mm; the peristome corresponds to 40-60 % of that diameter, proportionally bigger than the apical system; the interambulacral areas are four times larger than the ambulacral areas. The variation of the pedicellariae is shown with scanning electron microscopy. The specimens of the Mexican oceanic islands are markedly different when compared to those of the mainland. Conclusions: Eucidaris thouarsii has five well differentiated secondary spines, and also specific regionalization; the apical system varies according to the size of the Horizontal Diameter of the Test; the globiferous pedicellariae have intraspecific differences; and the tridentate pedicellariae are specifically regionalized. Resumen Introducción: Eucidaris thouarsii es una especie de erizo de mar, cidárido presente desde el Golfo de California hasta Ecuador. Su taxonomía está basada en descripciones generales de la forma de la testa, espinas primarias y secundarias, la linterna de Aristóteles, el sistema apical y peristoma. Objetivo: Redescribir E. thouarsii con descripciones detalladas, añadiendo nuevos caracteres taxonómicos. Método: Examinamos y reidentificamos 792 ejemplares, midiendo y analizando a detalle estructuras de valor taxonómico. Resultados: El diámetro horizontal de la testa va de 2.8 a 48 mm; el peristoma corresponde entre el 40-60% del diámetro horizontal de la testa, proporcionalmente más grande que el sistema apical; el área interambulacral es cuatro veces más grande que el área ambulacral. La variación en los pedicelarios se muestra con microscopía electrónica de barrido. Los ejemplares de las islas oceánicas mexicanas son claramente diferentes, comparados con los de la costa. Conclusiones: Eucidaris thouarsii tiene cinco tipos bien definidos de espinas secundarias que se encuentran regionalizadas en la testa, el sistema apical varía de acuerdo con el diámetro horizontal de la testa, los pedicelarios globíferos tienen diferencias intraespecíficas y los pedicelarios tridentados estas específicamente regionalizados.

The black sea urchin Arbacia lixula (Linnaeus, 1758) is one of the most domi-nant echinoids in the sublittoral communities of the Mediterranean Sea, where it is considered an essential structuring species by its grazing activity. The present work is considered to be the first study to address the diet of the species A. lixula in Algeria. This study aims to perform on the one hand; a temporal monitoring of the food preferences of two populations of A. lixula living in two different sites in shallow water (port of Salamandre, Stidia) on the coast of Mostaganem (Algeria) during the years 2015 and 2016, and on the other hand; get an idea of the variations of the different trophic sources used and appreciated by this echinoid. The quantitative and qualitative aspect is achieved by monitoring the evolution of the repletion index as well as the identification of the items present in the digestive contents by the contact method of Jones (1968). The results of this monitoring showed that it is an opportunistic species which adapts its diet according to the quality and quantity of food available. Arbacia lixula prefers encrusted coralline algae with a large faunal fraction. In areas rich in nutrients, the spines of these sea urchins may elongate to half the diameter of the test. Based on the results, A. lixula can be associated with habitat, seasonal changes or other specific environmental parameters that merit further development in order to fully understand its functioning in marine ecosystems.

We used shore boulders that had been previously colonized, and were scattered in a seagrass bed as models for islands. We tested two predictions of Island Biogeography theory: (1) small boulders harbored fewer species than large boulders, and (2) small boulders had higher rates of extinction than large boulders, as reflected in higher faunal replacement variability. We detected a definite relation between species richness and boulder size although not for all statistical models. We did not confirm higher compositional variability in small boulders.

International audience; Regulatory assessment of the effects of chemicals requires the availability of validated tests representing different environments and organisms. In this context, developing new tests is particularly needed for marine species from temperate environments. It is also important to evaluate effects that are generally poorly characterized and seldom included in regulatory tests. In this study, we designed an exposure protocol using European sea bass (Dicentrarchus labrax) larvae. We examined classical toxicological values (LCx) as well as behavioral responses. By comparing different hatching and breeding strategies, we defined the optimal conditions of exposure as non-agitated conditions in 24- or 48-well microplates. Our exposure protocol was then tested with 3,4-dichloroaniline (3,4-DCA), a recommended reference molecule. Based on our results, the 96 h LC50 for 3,4-DCA corresponded to 2.04 mg/L while the 168 h LC50 to 0.79 mg/L. Behavioral analyses showed no effect of 3,4-DCA at low concentration (0.25 mg/L). In conclusion, the present work established the basis for a new test which includes behavioral analysis and shows that the use of sea bass is suitable to early-life stage toxicity tests.

Flabellina rubrolineata was believed to have a wide distribution range, being reported from the Mediterranean Sea (non-native), the Red Sea, the Indian Ocean and adjacent seas, and the Indo-West Pacific and from Australia to Hawaii. In the present paper, we provide a redescription of Flabellina rubrolineata, based on specimens collected near the type locality of this species in the Red Sea. The morphology of this species was studied using anatomical dissections and scanning electron microscopy. To place this species in the phylogenetic framework and test the identity of other specimens of F. rubrolineata from the Indo-West Pacific we sequenced COI, H3, 16S and 28S gene fragments and obtained phylogenetic trees based on Bayesian and Maximum likelihood inferences. Our morphological and molecular results show a clear separation of F. rubrolineata from the Red Sea from its relatives in the Indo-West Pacific. We suggest that F. rubrolineata is restricted to only the Red Sea, the Arabian Sea and the Mediterranean Sea and to West Indian Ocean, while specimens from other regions belong to a complex of pseudocryptic species.

Two sympatric ecotypes (‘crab’ and ‘wave’) of Littorina saxatilis are adapted to different microhabitats. It has been claimed, based on the comparison of proteomic differentiation across ontogeny, that the wave ecotype may have evolved by paedomorphosis from an ancestor more similar to the crab ecotype. Here, we test the paedomorphosis hypothesis at a morphological level by comparing crab and wave specimens from two localities using the pattern of shell shape differentiation across ontogeny. The results obtained show a pattern of shell shape differentiation similar to the one observed in previous proteomic studies, but such a pattern could be caused by different modes of evolution, and not necessarily by paedomorphosis. This study emphasizes that in addition to studying the pattern of differentiation, the direction of the evolutionary change across ontogeny has to be analysed before conclusions can be drawn on particular developmental modes of evolution.

Ultra-morphology and pollen viability assessment are essential to understand evolutionary ecology and sterility problem, and to design hybridization program in cross-breeding. The pollen ultra-morphology of two Lilium Oriental hybrid cultivars, „Sorbonne‟ and „Siberia‟ were observed using scanning electron microscope. And the pollen germination condition in vitro and four dye tests methods for pollen viability were determined. The results showed that pollens of two Lilium Oriental hybrid cultivars were much alike in ultra-morphology with ellipsoidal shape, reticulate surface decoration and single germination ditch, indicating a close genetic relationship between two cultivars. The suitable medium for pollen germination of two cultivars composed of 10% sucrose, 0.1% boric acid and 0.5% agar. The pollen germination percent reached the highest at 25oC. Although I2-KI stain, TTC stain and peroxidase precipitation methods were not suitable for lily pollen viability test, the pollen viability tested by acetocarmine method were close to that by in vitro pollen germination at suitable condition, which suggested acetocarmine stain can be as a quick test method for pollen viability of Lilium Oriental hybrids. © 2018 Friends Science Publishers

Organisms have limited resources available to invest in reproduction, causing a trade‐off between the number and size of offspring. One consequence of this trade‐off is the evolution of disparate egg sizes and, by extension, developmental modes. In particular, echinoid echinoderms (sea urchins and sand dollars) have been widely used to experimentally manipulate how changes in egg size affect development. Here, we test the generality of the echinoid results by (a) using laser ablations of blastomeres to experimentally reduce embryo energy in the asteroid echinoderms (sea stars), Pisaster ochraceus and Asterias forbesi and (b) comparing naturally produced, variably sized eggs (1.7‐fold volume difference between large and small eggs) in A. forbesi. In P. ochraceus and A. forbesi, there were no significant differences between juveniles from both experimentally reduced embryos and naturally produced eggs of variable size. However, in both embryo reduction and egg size variation experiments, simultaneous reductions in larval food had a significant and large effect on larval and juvenile development. These results indicate that (a) food levels are more important than embryo energy or egg size in determining larval and juvenile quality in sea stars and (b) the relative importance of embryo energy or egg size to fundamental life history parameters (time to and size at metamorphosis) does not appear to be consistent within echinoderms., In two species of sea stars, exogenous food levels are more important than maternal investment in determining larval and juvenile quality. The relative importance of maternal investment to fundamental life history parameters (time to and size at metamorphosis) does not appear to be consistent within echinoderms.

Tunda Island has become one of the marine tourism spots that is much considered by tourists because it has good coastal ecosystems. To find out the suitablecondition of Tunda Island waters, benthic foraminifera were used in this area. Foraminifera have the potential to be a bioindicator, which can be seen from the distribution, simple anatomy of the body and its ability to form hard shells. The purpose of this study was to determine the abundance and diversity of foraminifera based on shell walls on the surface of the coastal sediments of Tunda Island. This research was conducted on August 2019. Six samples were used in this study to analyze the abundance and diversity of benthic foraminifera based on test walls on the coast of Tunda Island. The analysis showed that only 2 sub-orders were found, namely Rotaliina and Miliolina. The most common sub-orders found in all studied stations are the Rotaliina with an abundance of 55% and 45% for the Miliolina. Calculation of community structure with diversity values ranging from 1.55 to 2.24 and dominance values ranging from 0.13 to 0.38 indicate that environmental conditions are under pressure both naturally and anthropogenically.

The blue-black urchin has been widely known and utilized as food in the world, including Indonesia because sea urchin gonad can be consumed. However, the utilization of sea urchins in Gorontalo has not been performed. On the other hand, natural resources information is needed as the database for natural resources management in Tomini Bay. The aim of this study is to document the blue-black urchin Echinotrix diadema. This study conducted at Blue Marlin Beach, South Leato, Gorontalo, from November 2019 to December 2020. Sea urchin density was calculated with a 1 m × 1 m transect quadrate that positioned at interval 5 m in distance along 15 m of the transect line at the coral reef ecosystem. In parallel with the measurement of the density, sea urchin test diameter was measured with a Vernier caliper (0.01 mm accuracy), and the water temperature was measured with a thermometer. The results show that the average of sea urchin density is 3 ind. m–2 in November and December and 1 ind.m–2 in January. That density has no significant difference among the month. Moreover, the average size of the sea urchin test diameter is 60 mm in November, 63 mm in December, and 66 mm in January. The seawater temperature is 34 °C in November, 37 °C in December, and 33 °C in January. That results show that sea urchin density in the blue marlin beach is very low.

Fish is one of the foodstuffs that has a protein content that is needed by humans. Nowadays fish have been processed into many products that have longer durability, humans have used fish as a mixture in diversified products. Diversification of fishery products so that fish can be used in other forms such as instant noodles, biscuits, and traditional products such as making sago plates mixed with fish meat. The purpose of this study was to determine the content of E. coli and Salmonella sp. on sago products produced. This research was conducted in September-October 2019. Sampling of fish sago was carried out in Dehegila Village, Morotai Island Regency. Sample analysis was performed at the Khairun University Ternate Environmental Laboratory. The data obtained were then presented in a descriptive analytic and literature study. From the results of the study obtained by sago plate added skipjack tuna meat as well as the use of flavorings Based on the analysis of all sago samples there was bacterial growth with an average number

Sea urchin Tripneustes gratilla is one of an economically important fisheries resource product for localities at Wakatobi archipelago. High demands for sea urchin gonad have intensified high fishing activity. The hypothesis of this study is that sea urchins in Wakatobi have been overfished. To answer th at hypothes i s , the density and its test diameter size were measured at two different sites. Those two sites are Pulau Tomia (resident area) and Pulau Sawa (nonresident area and very distant from the localities). The results show that sea urchin density and its test diameter are significantly different. The densities (mean±SE) T . gratilla at Pulau Sawa and Pulau Tomia were 10±0.6 (ind.m -2 ) and 2.7±0.9 ind.m -2 , respectively. Moreover, the test diameter at Pulau Sawa and Pulau Tomia were 69.7±2.1 mm and 58.5±1.7 mm (mean±SE), respectively. These results have shown that overfishing has occurred. Therefore, sea urchin with test diameter 66–75 mm, 76–85 mm, and 86–95 mm have disappeared at Pulau Tomia. The C onclusion reveals that fishing of sea urchin Tripneustes gratilla at Pulau Tomia has been overfished.

Diarrhea is a cause of increasing mortality in infants and toddlers around the world. Diarrhea is a dangerous disease because it causes death and makes a case of outbreak. In Indonesia, the Trema orientalis L. plant is known as Anggrung. Trema orientalis L. leaves contain tannins especially polyphenols which have the ability to retain potassium which can cure ongoing diuresis. This study aims to determine the antibacterial activity of Anggrung leaves as an antidiarrheal drug caused by bacteria that cause diarrhea, namely Salmonella sp and the preparation of granules from leaves of Trema orientalis L. (Anggrung) which can inhibit the growth of Salmonella sp. and become an antidiarrheal drug. The results of the research carried out namely the leaf extract of Trema orientalis L. (Anggrung) has a strong inhibitory power due to the high concentration of the extract used. And for leaf granules Trema orientalis L. (Anggrung) preparations have a strong inhibitory power because the composition of the extract used is greater so it forms a large inhibitory zone. From the research conducted it can be concluded that the antibacterial testing of extracts and leaf granules preparations of Trema orientalis L. (Anggrung) has antibacterial activity.

Cadmium the form of undamaged elements but can change shape to different compounds. The low concentrations of toxic cadmium for all life, including plants, fish, birds, mammals (including humans), and microorganisms. The purpose of this research is to know the value of LC50-96 hours Cd2+on test biota. The test biota was Gambusia fish (Gambusia affinis), the test biota can represented the actual state of the environment. The study was divided into two stages, namely preliminary test and acute lethal toxicity (LC50-96 hours), each treatment repeated three times. Acute lethal toxicity test data were analyzed probit. The results showed that the value of LC50-96 hours Cd2+to fish gambusia was 0.03 ppm. While in the protease activity of cadmium exposed preliminary fish increased activity from the control fish.

Indonesia is the largest archipelagic country so it has enormous coastal potential as well. One of the coastal potential that has great benefits for the community is seaweed cultivation. Production of seaweed cultivation in NTB province in 2012 reaches 657,700 tons and increase every year. But in fact, the development of seaweed cultivation business have several obstacles, one of them is the presence of ice-ice disease that infects the seaweed Eucheuma cottoni species. This ice-ice disease causes a decrease in the quality and quantity of seaweed causing crop failure. This ice-ice disease attacks the thallus in the seaweed and causes the seaweed thallus to become brittle and breaks easily due to the lysis of epidermal cells and chloroplasts. The ice-ice disease is caused by a bacterial infection of Vibrio sp. which occurs when seaweed become stress due to adverse environmental conditions such as rising temperatures and salinity. The ice-ice disease can be threat using antibacterial compounds which found in plants such as tannins, flavonoids, and saponins. One of the plants that contain antibacterial is kirinyuh (Chromolaena ordorata). The antibacterial content on kirinuyuh leaves is extracted using a simple maceration method with aquadest as a solvent, and yields of extraction was diluted into concentrations of 20%, 40%, 60%, 80%, and 100%. Leaf extract of kirinyuh with variation of concentration was tested in vitro condition by using diffusion agar method with paper disk on solid NB media which has been overgrown with Vibrio sp. The result of in vitro test using diffusion agar method with paper disk was obtained that kirinyuh extract is able to inhibit the growth of Vibrio sp. bacteria with the widest inhibit zone is 10.315 mm at 100% concentration.

The ability of bottom-dwelling marine fauna to repair injured body parts is critical to the survival of individuals from disturbances that inflict wounds. The phylum Echinodermata, in particular, exposes a pronounced ability to regenerate skeletal damages. Regeneration of lost body parts of stellate echinoderms (crinoids, asteroids and ophiuroids) is a well-documented phenomenon, whereas sea urchins (echinoids) have received much less attention. Here we report, for the first time, a field observation on an adult sea urchin of the genus Strongylocentrotus in its natural habitat, exposing severe skeletal damage but remarkable survivorship. The sea urchin was revealed by analysing a time series of seafloor images taken during a lander deployment in a rhodolith bed in the polar waters of northern Spitsbergen, Svalbard. Despite the loss of half the aboral region of the test, including existential organs, the sea urchin continued to move across the seafloor for more than 43 h, thereby escaping another predation attack by a large crab. The observed behaviour is grounded in the peculiarity of the sea urchins’ nervous system where locomotion is controlled by a decentralised ectoneural system in the epithelium, large parts of which had remained intact after the traumatic event. Our field observation thus documents initial post-traumatic survival of severe lesions, which is a basic prerequisite for beginning repair processes.

Specimens displaying unusual ( " abnormal " or aberrant) test morphologies, for example, the presence of twin embryos, or test repair after damage, are reported from Lower Cretaceous Orbitolinidae. Twin embryos (which have not always been recognized as such in the literature) are described from the upper Barremian of Tibet and France (Palorbitolina lenticularis), the upper Albian of Somalia (Orbitolina gr. sefini), and the upper Aptian-early Albian of Texas (e.g., Mesorbitolina texana). Twin embryos have so far only been reported from the Orbitolininae (with complex embryo), and not from the Dictyoconinae (with simple embryo). Repaired partially damaged tests (the damage possibly caused by predation or mechanical fracture) are observed in lower Aptian orbitolinids from Iran. Regeneration after damage (bioadjustment) leads to malformed tests.

Phenol degrading bacteria can be found in various habitats in marine environments. This study aims to obtain bacteria from sediments that are able to degrade phenol. The process of bacterial purification and degradation was carried out from August to September 2018 at the Marine Microbiology Laboratory, Department of Marine Sciences, Faculty of Fisheries and Marine, University of Riau. Analysis of the reduction in phenol concentration was carried out using the APHA 5530 method using UV-VIS spectrophotometry conducted at the Health and Environment Laboratory. The bacterial isolates used as test bacteria were isolates BF1A, BF4B and BF9C. Bacterial and biochemical tests were carried out for all bacterial isolates. Two isolated showed mehyl red negative, all isolates were motile. Three isolates were positive catalase, able to ferment glucose and sucrose fermented citrate and two isolat were Gram negative bacterial. The three bacterial isolates were able to degrade phenol with the highest degradation for 1ppm shown in isolates BF1A, the highest degradation of concentrations of 2 ppm and 3 ppm was shown in isolates BF9C. Thus, the isolat BF9C was able to degrade the highest phenol.

Commonly known as “purple sea urchin,” Paracentrotus lividus occurs in the Mediterranean Sea and the eastern Atlantic Ocean. This species is a highly appreciated food resource and Italy is the main consumer among the European countries. Gonads are the edible part of the animal but they represent only a small fraction (10–30%) of the entire sea urchin mass, therefore, the majority ends up as waste. Recently, an innovative methodology was successfully developed to obtain high-value collagen from sea urchin by-products to be used for tissue engineering. However, tissues used for the collagen extraction are still a small portion of the sea urchin waste (2 technique, characterized by low environmental impacts. Fatty acids and carotenoids were successfully and selectively extracted and identified depending on the physical parameters of the supercritical CO2 extraction. Finally, the exhausted powder was extracted by solvent-based procedures to yield PHNQ. The presence of Spinochrome A and Spinochrome B was confirmed and extracts were characterized by a remarkably high antioxidant activity, measured through the 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay. Overall, the selective and successive extraction methods were validated for the valorization of waste from sea urchins, demonstrating the feasibility of the techniques targeting added-value compounds.

Since its existence, paleoceanography has relied on fossilized populations of planktonic foraminifera. Except for some extreme environments, this calcareous protist group composes most of the silty-to-sandy fraction of the marine sediments, i.e., the foraminiferal oozes, and its extraction is probably the simplest among the currently existing set of marine fossil proxies. This tool has provided significant insights in the building of knowledge on past climates based on marine archives, especially with the quantification of past hydrographical variables, which have been a turning point for major comprehensive studies and a step towards the essential junction of modelling and paleodata . In this article, using the modern analog technique and a database compiling modern analogs (n = 1007), we test the reliability of this proxy in reconstructing paleohydrographical data other than the classical sea-surface temperatures, taking advantage of an update regarding a set of extractions from the World Ocean Atlas for transfer functions. Our study focuses on the last glacial period and its high climatic variability, using a set of cores distributed along the European margin, from temperate to subpolar sites. We discuss the significance of the reconstructed parameters regarding abrupt and extreme climate events, such as the well-known Heinrich events. We tested the robustness of the newly obtained paleodata by comparing them with older published reconstructions, especially those based on the complementary dinoflagellate cyst proxy. This study shows that the potential of planktonic foraminifera permits going further in reconstructions, with a good degree of confidence, however, this implies considering ecological forcings in a more holistic perspective, with the corollary to integrate the message of this fossil protist group, i.e., the obtained parameters, in light of a cohort of other data. This article constitutes a first step in this direction.

It is generally assumed that the soil environment played an important role in the evolution of life on land, as a transition medium between water and air. This idea was already formulated by M.S. Gilharov in 1949 but it has never been tested systematically against modern phylogenetic reconstructions from DNA data. In this paper I review the phylogenies of soil invertebrate lineages that have been published in the last decade, as a guide to test Ghilarov’s hypothesis. I propose to distinguish between major and minor terrestrializations and six different evolutionary scenarios. The various lineages of soil invertebrate (nematodes, tardigrades, crustaceans, apterygotes, insects, myriapods, chelicerates, flatworms, earthworms, potworms and snails) show different pathways of terrestrialization. Some lineages seem to have conquered the land directly from the marine environment, others through intermediate habitats (intertidal, caves and freshwater). The review illustrates that the study of soil invertebrates holds many promises for enriching evolutionary sciences.

Conspecific alarm cues crushed from Mesocentrotus nudus prevent sea urchins from foraging the kelp, but do not repel them far away from the kelp. However, it remains largely unknown of whether this phenomenon was affected by conspecific alarm cues or by the attraction of the kelp. The present study found no significant difference in the duration in the danger area with or without the kelp around conspecific alarm cues. This suggests that the phenomenon is the strategy of sea urchins but not by the attraction of kelp. We found that conspecific alarm cues appearing between the kelp and sea urchins significantly affected foraging behavior of sea urchins fasted for 21 days. This indicates that conspecific alarm cues can effectively prevent fasted sea urchins from foraging the kelp. Further, there was no correlation between foraging velocity and the duration in the danger area. Pearson correlation analysis revealed no significant correlation between foraging velocity and the duration in the safety area close to different amounts of conspecific alarm cues, suggesting that conspecific alarm cues prevent sea urchins with strong foraging ability to forage. Collectively, the present results indicate that conspecific alarm cues as highly available biological barriers are cost-effective approaches to preventing overgrazing of sea urchins in the protection of kelp beds ecosystems. Notably, the present study is a short-term laboratory investigation that does not consider the complexity of natural conditions. Future studies are essential to test the present findings in the field.

Concentrations of 129I in coastal surface sediment samples from the east coast of Aomori, Japan, 2–65 km away from the wastewater outlet of the nuclear fuel reprocessing plant at Rokkasho, Japan, were measured from 2006 to 2010. No clear effect on 129I/127I atom ratios in marine sediments was observed, although 129I was discharged from the plant, during its test operation using actual spent fuel, mainly between 2006 and 2008. The ratio in sediments collected at a fishing port at the mouth of a brackish lake increased in 2007, showing that the 129I migrated from the lake to the port.

Soft coral is one of the marine organisms that produce secondary metabolites materials and has potency as anticancer. There is much research to find bioactive compounds in the organism, but it still lacks data to find potency of bioactive in soft coral that lives under acidification pressure. The objectives of this study are to determine the characteristic of acidification in Krakatau seas and to assess the potency of cytotoxic activity from soft coral Sarcophyton. Sampling was conducted in three locations, Legon Tuo, Legon Cabe, and Umang-umang Island, to take the sample and measure water quality. Cytotoxic test using MTT method (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolinon) to MCF-7 cancer cell line to measure growth inhibition percentage. Data were analyzed using ANOVA, post hoc analysis, and multivariate analysis. Water quality in Legon Tuo and Legon Cabe have significant different to Umang-umang Island. However, Legon Tuo and Legon Cabe are suitable as acidification site, while Umang-umang Island as the reference site. The characteristic of Krakatau seas, especially in Legon Tuo and Legon Cabe study site, was categorized in low acidification. In the cytotoxic activity, soft coral Sarcophyton from Legon Cabe (acidification site) is more potential than soft coral from Umang-umang Island (reference site).

Entre los grupos cazadores-recolectores que ocuparon el humedal del río Paraná inferior durante el Holoceno tardío, el conjunto más numeroso de adornos es el de las cuentas y tembetás hechos sobre valvas de moluscos. En trabajos previos observamos que estos elementos presentan similitudes morfológicas a nivel intersitio, con pequeñas variaciones formales. En este trabajo evaluamos la posibilidad de que estos elementos hayan funcionado como demarcadores sociales. En este sentido esperamos un patrón homogéneo tanto en la forma general y sus atributos, como en el tamaño. Para ello analizamos métrica y morfológicamente los conjuntos malacológicos provenientes de diez sitios arqueológicos del área. Los resultados muestran tendencias diferentes para las cuentas y los tembetás. Las primeras se distribuyen de manera homogénea en el espacio con un patrón morfológico y métrico compartido que sólo excluye uno de los sitios arqueológicos. Los tembetás, por su parte, son menos frecuentes y presentan dos variantes morfométricas que pueden responder a variaciones individuales o reflejar parcialidades étnicas. Among hunter-gatherer groups that inhabited the low Paraná wetland during Late Holocene, the most numerous assemblages of ornaments are composed by shell beads and tembetás. In previous works we observed that the assemblages show inter-site morphological similarities with little formal variations. In this paper we test the idea that these elements were used as social markers. Consequently, we expect an homogeneous pattern in the general form and the form of their attributes, as well as the metrical values. For this purpose, we analyse metrical and morphological data of shell assemblages from ten archaeological sites of the study area. Results show different tendencies for shell beads and tembetás. Shell beads are homogenously distributed in the region with a shared morphologic and metric pattern that only excludes one of the archaeological sites. Tembetás are less frequent and show two morpho-metric variants that could be a response either to individual variability or to ethnic identification. Fil: Buc, Natacha. Secretaría de Cultura de la Nación. Dirección Nacional de Cultura y Museos. Instituto Nacional de Antropología y Pensamiento Latinoamericano; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Acosta, Alejandro Alberto. Secretaría de Cultura de la Nación. Dirección Nacional de Cultura y Museos. Instituto Nacional de Antropología y Pensamiento Latinoamericano; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Loponte, Daniel Marcelo. Secretaría de Cultura de la Nación. Dirección Nacional de Cultura y Museos. Instituto Nacional de Antropología y Pensamiento Latinoamericano; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Diatoms are among the most commonly used bioindicators. Correct taxonomic identifications are critical to their use as bioindicators because closely related diatom species can respond diffe...

To assess the risk of chemical contaminants it is desirable to derive toxicity data from representative species of the ecosystem intended to be protected. However, species of occurrence in Brazil are rarely used in toxicity tests, especially for marine and estuarine environments. To address this need, we evaluated the toxicity of different toxicants such as metals and organic compounds to marine invertebrates of Brazilian occurrence, representative from tropical regions and cultivated in laboratory. We used two epibenthic test species of Brazilian occurrence, Parhyale hawaiensis, a deposit feeding amphipod and Nitocra sp, a harpacticoid copepod. Nitocra sp. was more sensitive than other copepods to zinc, and more sensitive than P. hawaiensis to disperse dyes. Sensitivity species distribution revealed that Nitocra sp. and P. hawaiensis were similarly responsive as other marine species to zinc, and Nitocra sp. was among of the most sensitive species. Moreover, our study highlighted that organic compounds are poorly explored in toxicity evaluation with marine organisms; therefore, more studies need to be carried out to assess the toxicity of different substances using marine and estuarine organisms representative of tropical ecosystems.

Testate amoebae are a group of free-living heterotrophic protists that have an organic shell or test and play a very good role as bioindicators in the ecological monitoring of environment. Inspite of the importance the percentage contribution of free living protozoans recorded from the Himalayan landscape is only about 12% of the total free living protozoans of India. This portrays a meagre diversity of species from such a highly diversified ecosystem of Himalaya and the true diversity may be far above the recorded number of species. In this study it is herewith reporting two species of testate amoebae viz., Assulina quadratum Van Oye, 1958 and Cyclopyxis leidy Couteaux et Chardez, 1981 for the first time from India from Sangla Valley, Himachal Pradesh. Key words: Assulina quadratum, Cyclopyxis leidy, bioindicator protists, moss-dwelling testate amoebae, soil protists, new biogeographic records, Sangla Valley, Himachal Pradesh, India.

Mammals adapted to unpredictable and low-energy environments often evolve a “bet-hedging” life history strategy characterized by less costly reproductive outputs over a longer and slower-growing life. In contrast, species adapted to more predictable (i.e., low variation) and higher energy environments may evolve greater fecundity over a shorter and faster-growing life. We tested whether this known interspecific pattern also occurs within a species. We compared life history traits of the ringed seal (Pusa hispida) in the Canadian High Arctic to those closer to the southern limit of the species' circumpolar distribution. We found that northern seals grew slower than southern seals (Brody growth coefficient), achieved a greater asymptotic body weight (82 and 69 kg vs. 74 and 54 kg female and male, respectively), reached sexual maturity later (6.1 years vs. 4.5 years), had lower fecundity (1.8 years vs. 1.3 years interbirth interval), longer average lifespan (5 years vs. 3 years median age), and greater movements (1,269 vs. 681 km). Mating systems also likely differed with northern seals showing morphological evidence of a promiscuous mating system with potential sperm competition as indicated by greater relative testes size. The northern region was also characterized by more unpredictable environmental timing of seasonal events, such as spring sea ice breakup. Life history variation between the intraspecific groups of seals appears to agree with interspecific patterns and provides a better understanding of how species' life history parameters shift in concert with environmental conditions.

Newly-developed methods for utilizing performance surfaces—multivariate representations of the relationship between phenotype and functional performance—allow researchers to test hypotheses about adaptive landscapes and evolutionary diversification with explicit attention to functional factors. Here, information from performance surfaces of three turtle shell functions—shell strength, hydrodynamics, and self-righting—is used to test the hypothesis that turtle lineages transitioning from aquatic to terrestrial habitats show patterns of shell shape evolution consistent with decreased importance of hydrodynamic performance. Turtle shells are excellent model systems for evolutionary functional analysis. The evolution of terrestriality is an interesting test case for the efficacy of these methods because terrestrial turtles do not show a straightforward pattern of morphological convergence in shell shape: many terrestrial lineages show increased shell height, typically assumed to decrease hydrodynamic performance, but there are also several lineages where the evolution of terrestriality was accompanied by shell flattening. Performance surface analyses allow exploration of these complex patterns and explicit quantitative analysis of the functional implications of changes in shell shape. Ten lineages were examined. Nearly all terrestrial lineages, including those which experienced decreased shell height, are associated with morphological changes consistent with a decrease in the importance of shell hydrodynamics. This implies a common selective pattern across lineages showing divergent morphological patterns. Performance studies such as these hold great potential for integrating adaptive and performance data in macroevolutionary studies.

The research about species richness pattern and elevational Rapoport's rule (ERR) have been carried out mostly in the temperate regions in the recent years and scarcely in the tropical mountains; meanwhile, it is unclear whether the ERR is consistent among different life‐forms and phytogeographic affinities. Here, we compiled a database of plant species of Mount Kenya, a tropical mountain of East Africa, and divided these species into twelve groups depending on the life‐form and phytogeographic affinity of each species. We inspected the species richness pattern of each group along the elevation gradient and also tested ERR of each group using Stevens' method. Our results showed that species richness of the total species showed a positively skewed (hump‐shaped) pattern along the elevation gradient and different life‐forms and phytogeographic affinities showed similar hump‐shaped patterns as the total species. The average elevation range size of the total species and herbaceous species showed increasing patterns along the elevation gradient, while lycophytes and ferns, and woody species showed an obvious downward trend after peaking in the high elevation regions. We concluded that the widely distributed herbaceous species which also have broad elevation range sizes are more applicable to ERR, while the narrowly distributed woody species with small elevation range sizes occurring in the higher elevations could reverse ERR. Therefore, we concluded that the ERR is not consistent among different organisms in the same region.

The phytotechnology concept that is applied for a bio-desalination reactor become a new desalination technology. The desalination technology can be called as bio-desalination technology to remove ions of Na+ and Cl- in brackish or saline water using mangrove plant. Before the mangrove plants were used in bio-desalination technology, the preliminary phytotoxicity test was conducted. The purpose was to determine the salinity concentration at which the mangrove species of Rhizophora mucronata can survive. The preliminary phytotoxicty test was carried out using a plastic reactor that was designed as a reed bed system. The reactors filled with gravel, sand, and artificial saline water. The variation of the NaCl concentrations were 0 mg/L as control, 10,000; 20,000; 30,000; 40,000, and 50,000 mg/L. The physical observation of the survival condition of Rhizophora mucronata was carried out during the preliminary test for 7 days. The analysis of Scanning Electron Microscopy (SEM) on Rhizophora mucronata was conducted at the end of exposure. The results showed that Rhizophora mucronata could not survive at the concentrations of 40,000 and 50,000 mg/L. Rhizophora mucronata changed the color of the leaves to brown and the stems become softer. Multiple cell damage and the decreasing trend of sodium and chloride amounts occured on roots and stems at the salinity concentration of 50,000 mg/L. In conclusion, the high of salinity concentration (> 30,000 mg/L) can be toxic to Rhizophora mucronata.

Metridium senile, the fluffy (or plumose) sea anemone, is a circumboreal species adapted to the cold northern oceans. We performed a 40-day experiment on 108 individuals of M. senile collected from the Akkeshi-ko estuary in Japan to test their survivability in higher temperatures and their upper and lower salinity survivability limits. In addition to using survivorship to determine if there is a smaller tolerance range than the extreme limits of temperature and salinity, we used asexual reproduction via pedal laceration as an indicator of the most favorable environmental conditions for M. senile. The resulting limitations are used to both broaden our understanding of the biology of M. senile and to assess potential effects of changing oceanic conditions, since M. senile is unable to survive in warm water temperatures or in extreme salinities. Our results support the use of pedal laceration by M. senile as a way to quickly colonize an area with favorable environmental conditions in order to preserve a well-adapted phenotype.

Chlorine efficacy as a biocide for ballast water treatment was investigated under cold- and warm-water temperatures across winter and summer seasons. Freshwater phytoplankton samples were collected and acclimated under in situ environmental conditions ranging from 2 to 22 °C. Samples were exposed to seven chlorine treatments (from 0.02 to 5.0 ppm), in addition to a control (0.0 ppm). Free-chlorine concentrations, phytoplankton abundance, and photosynthetic efficiency were measured up to 48 h following treatment. After 4 h of treatment at concentrations less than 0.22 ppm, phytoplankton densities were reduced by more than 50%, without cell resurgence. Similar reduction was recorded immediately after exposure when chlorine concentrations were higher than 3.0 ppm. After 8 h, free chlorine neared 0.0 ppm for initial chlorine concentrations below 1.2 ppm, irrespective of temperature regime. Winter phytoplankton exhibited slightly lower mortality to chlorine exposure regardless of the temperature, although they also exhibited lower photosynthetic efficiency. Despite a general absence of significant effect of temperature on the chlorine decay, our results suggest that higher doses of chlorine or longer exposure times may be required during winter to achieve full treatment effect. Tests at large scales are needed to further confirm these findings.