Habitat protection for sensitive species: Balancing species requirements and human constraints using bioindicators as examples

Vertebrates have particular habitat needs as a function of life cycle and reproductive stage. This paper uses four species as examples to illustrate a paradigm of environmental assessment that includes physical, biological, toxicological and human dimensions. Species used include Chinook salmon (Oncorhynchus tshawytscha), northern leopard frog (Rana pipiens), northern pine snake (Pituophis m. melanoleucus), and red knot (Calidris canutus rufa, a sandpiper). The life cycles of these species include reliance on habitats that are aquatic, terrestrial, aerial, or combinations of these. Two species (frog, snake) are sedentary and two (salmon, sandpiper) are long-distance migrants. While some measurement endpoints are similar for all species (reproductive success, longevity, contaminant loads), others vary depending upon life cycle and habitat. Salmon have a restricted breeding habitat requiring coarse sand, moderate current, and high oxygen levels for adequate egg incubation. Leopard frogs require still water of appropriate temperature for development of eggs. Pine snakes require sand compaction sufficient to sustain a nest burrow without collapsing, and full sun penetration to the sand to allow their eggs in underground nests to incubate and hatch. Red knots migrate to high Arctic tundra, but incubate their own eggs, so temperature is less of a constraint, but feedinging habitat is. These habitat differences suggest the measurement endpoints that are essential to assess habitat suitability and to manage habitats to achieve stable and sustainable populations. Habitat use and population stability have implications for human activities for some, but not all species. Salmon are important economically, recreationally, and as part of Native American culture and diet. Red knots are of interest to people mainly because of their long, intercontinental migrations and declining populations. Other measurement endpoints for these four species illustrate the differences and similarities in metrics necessary to assess habitat needs. The implications of these differences are discussed.

Role of the Zinc Nutritional Status on Main Physiological Bioindicators of the Pecan Tree

The purpose of this study was to analyze the effect of Zn nutritional status on the content of pigments, nonstructural carbohydrates, foliage proteins and amino acids of the pecan tree, as possible bioindicators of Zn deficiency. The experimental design was completely random with three Zn nutritional statuses: Normal, Intermediate and Deficient, being selected considering visual symptomatology. On all three nutritional statuses, the concentration of photosynthetic pigments was determined as well as of total soluble proteins and amino acids. Obtained results indicate that Zn deficient nutritional status was characterized by minimum photosynthetic pigment, protein concentrations, maximum amino acid and nonstructural carbohydrate concentrations. While the normal Zn nutritional status presented maximum photosynthetic pigments, proteins concentrations, minimum amino acids and carbohydrate concentrations. On the other hand, intermediate Zn nutritional status was characterized by a medium level between the other two Zn nutritional statuses. Finally, we stress the fact that pigments, proteins, amino acids and nonstructural carbohydrates may be good physiological indicators related to Zn nutritional status on pecan trees.

Study on the mussel (Mytilus viridis ) as an ^(90)Sr contaminative bioindicator of a sea area

It is well known that mussels have been applied more and more to monitoring marine pollution, and have been reported on the marine radioactive monitoring. The majority concentrates the attention on the study of monitoring active products. However, the report on monitoring fission products is rare. T. R. Rice reported that the phytoplankton could concentrateSr, but its drawback is too large mobility to reflect the radioactive level of the specific sea area. For this purpose, the paper applies the mussel, which life range is more fixed, to discuss the possibility of monitoringSr.

Meiobenthos Assemblages as Bioindicators for Coastal Pollution Assessment

Coastal pollution assessment is a pressing matter as the anthropogenic pressure continues to increase worldwide. A leading approach to assess coastal pollution is using bioindicators. However, identifying species is time-consuming and demands profound morphological knowledge. Our goal was to find the meiobenthic composition in each pollution level. By utilizing the meiobenthic assemblage’s ratios, we will be able to indicate the pollution level. We examined the meiobenthos distribution at three sites exposed to a pollution gradient. We quantified the changes in the fauna assemblage in the community phylum level, focusing on nematodes and foraminifera (90% of the total population). Over 400 samples were examined, covering an annual seasonal cycle. Nematodes population dominated in the polluted coast. Nematodes density increased with the pollution level, up to seemingly harmful levels of pollution. In contradiction, the foraminifera flourished in the control site and exhibited an inverse relationship to the nematodes. We witnessed drastic changes in the entire meiobenthic population in the winter, which we speculate that originated from winter turbulences. We suggest that nematodes-foraminifers’ population ratios may be utilized as bioindicators for assessing coast intertidal zone pollution levels.

Monitoring of Environmental Mercury Exposure Using Hair as Bioindicator and the Study of Potential Factors Affecting on It in Karachi

The World Health Organization (WHO), Environmental Protection Agency (EPA), and International Atomic Energy Agency (IAEA) have recommended the use of hair for worldwide environmental monitoring. Mercury exposure to the inhabitants of Karachi was assessed by using hair as bioindicator. Hair samples of 200 residents of Karachi were collected and analyzed through cold vapor atomic absorption spectroscopy (CVAA) technique for mercury concentration. The effects of age, gender, working status, location, food and smoking habit were investigated. Control region showed a positive correlation between HHg and age of donor while no such correlation was observed for polluted regions. Mercury exposure through cosmetic usage in female was only pronounced in control region. These results indicate that environmental pollution dominates other potential factors. Age and smoking habit were not found to be the influencing factors while an elevated mean level of mercury was noticed for regular fish consumers than rarely fish consumers. 95.33% of the samples contained HHg greater than the permissible level of 2 μg?g?1 set by WHO. An apparently healthy male donor had HHg concentration (28.24 μg?g?1) closer to the high risk concentration of 30 μg?g?1 based on WHO criteria. Whereas, two female donors of the age group of 41-50 years had HHg concentrations (10.82 and 11.84 μg?g?1) higher than the NOAEL (no observed adverse affects level) value (10 μg?g?1) for females which is associated with fetus neurotoxicity. However, no symptoms of mercury toxicity were visible. The results indicate the alarming condition of pollution in the city which should be taken into further consideration.

Determining Environmental Impacts for Sensitive Species: Using Iconic Species as Bioindicators for Management and Policy

Environmental assessment of impacts, management, and policy are important aspects of protection of human health and the environment. Assessing the impacts of human activities requires selection of bioindicator species that can be used to assess, manage, and develop public policies that ensure ecosystem integrity, and therefore sustainability of social, cultural, and economic systems. With the use of Chinook Salmon (Oncorhynchus tshawytscha), Pacific Cod (Gadusmacrocephalus), Mallard (Anas platyrhynchos), and Red Knot (Calidris canutus rufa), we explore assessment and measurement endpoints, and their relationship to management and development of public policy. This combination of fish and birds provides a diversity of life histories, ecosystem roles, human values, and resource use to explore their use as bioindicators and endpoints. It also allows examination of 1) conservation and protection of species and biodiversity, 2) protection of ecosystems, 3) provision of goods and services, and 4) societal well-being.

Inventory and Distribution of Benthic Macroinvertebrates, Indicators of Water Quality in Four Forested Watercourses in Centre Region of Cameroon

The inventory of benthic macroinvertebrate species was carried out in some streams of the Mefou catchment area, from August 2021 to August 2022, in order to determine the biological groups that make up the population and characterise these environments. The dataset acquired during this study made it possible to update the existing database and contribute to the knowledge of the biological groups associated in these environments, and to provide additional information on the existing ones in relation to bioindication. Overall 80 families were identified and, on the basis of frequencies of occurrence greater than 75%, 22 families were retained as potential biological indicators. The remarkable diversity of insects and the low abundance of Diptera reflect the low degradation of environments and the good quality of water. The high diversity indices obtained reflect the maintenance of the favourable ecological conditions that favours the development of a balanced and, integrated biological community capable of adapting to changes.

Zebrafish as a possible bioindicator of organic pollutants with effects on reproduction in drinking waters

Organic contaminants can be detected at low concentrations in drinking water, raising concerns for human health, particularly in reproduction. In this respect, we attempted to use the zebrafish as a bioindicator to detect the possible presence of these substances in drinking water, aiming to define the most relevant parameters to detect these substances, which particularly affect the development and reproduction of zebrafish. To this end, batches of30 embryos with the chorion intact were cultured in drinking waters from different sources,throughout their full life-cycle up to 5 months, in 20 L tanks. Six replicates were performed in all water groups, with a total of 24 aquariums. Two generations（F0 and F1） were studied and the following parameters were tested： in the F0 generation, survival and abnormality rates evaluated at 5 dpf（days post-fertilization） and at 5 mpf（months post-fertilization）,the onset of spawning and the fertility rate from 3 mpf to 5 mpf, and the sex ratio and underdeveloped specimens at 5 mpf. Furthermore, in the F0 offspring（F1）, survival and abnormality rates were evaluated at 5 dpf and the hatching rate at 72 hpf. These results revealed that the hatching rate is the most sensitive parameter to distinguish different levels of effects between waters during the early life stages, whereas the rate of underdeveloped specimens is more suitable at later life stages. Regarding adult reproduction, fertility rate was the most sensitive parameter. The possible reversibility or accumulative nature of such effects will be studied in future work.

A New Foraminiferal Bioindicator for Long-Term Heat Stress on Coral Reefs

Coral reefs are in terminal decline.For conservation to be effective,naturally depauperate reefs must be distinguished from those recently degraded by humans.Traditional reef monitoring is time consuming and lacks the longevity to make this distinction.Success in using foraminifera as bioindicators for reef health has hitherto levered their response to nutrients.Because ocean heat waves are the dominant driver of coral bleaching and death,there is compelling motivation to develop new foraminiferal bioindicators that inform on temperature stress over meaningful timescales.This study focuses on identifying which foraminifera respond systematically to the temperature stress that kills corals.Statistical models were used to compare endosymbiont-bearing foraminiferal families,collected along a heat-stress gradient spanning the Solomon Islands and New Caledonia,to live coral cover at the same sites.Results indicate that Amphisteginidae foraminifera and coral cover show a significant decline in abundance as heat stress increases along the transect sites.Furthermore,ocean productivity and salinity,both recognized environmental influences on foraminifera,are shown to be subordinate to temperature in their sway of this ecological patterning.These findings indicate the potential for using foraminifera to develop new indices capable of quantifying long-term thermal impacts on reefs.

Testing the effectiveness of conservation management within biosphere reserves:the case of the Mexican deer mouse(Peromyscus mexicanus)as a bioindicator

Biosphere reserves are protected areas whose purpose is to combine conservation and sustainable development.However,their effectiveness has not been tested sufficiently,especially from an ecological and genetic ap­proach.In this sense,the Peromyscus genus represents an excellent bioindicator to address these questions,due to its short life and high evolutionary rate and fecundity.For conservation managers,genetic structure can in­crease the rate of loss of genetic diversity because alleles exclusive of a subpopulation are more likely to disap­pear as a consequence of genetic drift in comparison with a panmictic population.Here we analyzed the abun­dance,movement distances,morphology/morphometry and genetic structure of 3 populations of Mexican deer mouse(Peromyscus mexicanus)located in different protected zones of La Tigra National Park(Honduras).Our results are consistent among the 3 approaches and showed the highest values of abundance,morphometry and genetic diversity in the population located at the core zone,whereas non-statistically significant differenc­es were found between buffer and transition zone populations,suggesting suitable effectiveness of conservation management in the core zone but a lack of ecological buffering function of the other zones.In addition,the low movement distances and high genetic structure among the studied populations provide evidence of poor con­servation management in the buffer and transition zone.Thus,we discuss the utility of the novel methodology used in this work,combining morphometry,abundance and genetics,in testing the effectiveness of conservation strategies in biosphere reserves,and the value of the Peromyscus genus as a bioindicator.

A summary of Copepoda:synthesis,trends,and ecological impacts

Copepoda are one of the most significant animal groups present in aquatic ecosystems.Ecologists,evolutionary biologists,and biotechnologists continue to test new methods to study the application of Copepoda as model organisms in various fields of pure and applied science,from evolution and ecology to aquaculture as live feed,as biological control of mosquito larvae,as biological indicators of water and sediment quality,in environmental monitoring and as a source of protein in the food industry.This paper reviews the current progress and trends within copepod research from a number of different perspectives.We emphasize the importance of Copepoda and the necessity of strengthening research on various topics related to copepod biology,some of which are of great significance to local sustainable development.

Macroinvertebrates as Bio Indicators of Water Quality in Pinyinyi River, Arusha Tanzania

Rivers are important for aquatic biodiversity. Anthropogenic activities degrade rivers and decrease their capacity to offer ecosystem services. This study used macroinvertebrates to assess the impact of anthropogenic activities on the Pinyinyi River during dry and wet season. Abundance of macroinvertebrates, average score per taxon and Shannon Weiner Species Diversity Index were used to state the ecological status of Pinyinyi River. Because the abundance of macroinvertebrates can be affected by change in water quality, some of the physicochemical parameters were also measured. A macroinvertebrates hand net is used to collect the macroinvertebrates per sampling point. DO, temperature, pH, turbidity and TDS were measured in-situ using HI-9829 Multiparameter and BOD was measured in the laboratory using Oxydirect levibond method. A total of 164 macroinvertebrates were collected and identified from Pinyinyi River during dry and wet season. They belong to 13 families. The most abundant taxa were mosquito larva, Diptera (41.07%) and aquatic caterpillar, Lepidoptera (23.21%) during dry season representing about 64.28% of the total macroinvertebrates whereas the least abundant taxa were pouch snail (16.07%) and dragonflies, Odonata (19.64%) during dry season representing about 35.72% of the total macroinvertebrates. The most abundant taxa collected during wet season were aquatic earthworm, haplotaxida (19.44%), midges, Diptera (17.59%), black flies, Diptera (15.74%) and creeping water bugs, hemiptera (12.96%) whereas the least abundant were pigmy back swimmers, hemiptera (2.78%), snail (3.7%), predacious dividing beetle (4.63%) and coleopteran (4.63%). Average Score per taxon of Pinyinyi River during dry season was 5.25 and 3.6 during wet season. The Shannon Weiner Species Diversity Index was 1.318 during dry season and 2.138 during wet season. Based on the score, Pinyinyi River is moderately polluted during dry season and seriously polluted during wet season. Based on index, Pinyinyi River has low diversity of macroinvertebrates during dry season and highly in diversity of macroinvertebrates during wet season. Moreover, it was found that, agricultural activities, livestock keeping, bathing and washing alter physicochemical parameters of Pinyinyi River and hence change the abundance of macroinvertebrates as well as the quality of water. The study, therefore, recommends that the source of pollutants should be controlled and the river regularly monitored by the relevant authorities.

Determination of Heavy Metals and Polycyclic Aromatic Hydrocarbons (PAH) Contents Using the Lichen<i>Dirinaria picta </i>in Universiti Kebangsaan Malaysia

A biomonitoring study on lichens was conducted to assess the levels of atmospheric heavy metal and polycyclic aromatic hydrocarbon (PAH) at ten sites at the Universiti Kebangsaan Malaysia Campus, Bangi, Selangor, Malaysia. Dirinaria picta, epiphytic lichen which commonly found at lowland areas was used as the bioindicator in this study where samples were collected from the bark of palm trees at sites ranging from areas with high volume of traffic to isolated areas in the campus. Eight metals (Cr, Fe, Co, Ni, Cu, Zn , Al, Pb), and ten PAH;naphthalene (PAH1), acenaphtylene (PAH2), acenaphthene (PAH3), fluorine (PAH4), anthracene (PAH5), phenanthrene (PAH6), fluoranthene (PAH7), pyrene (PAH8), benzo (b) anthracene (PAH9) and chrysene (PAH10) were analyzed in the naturally growing thallus of Dirinaria picta. The average concentration of the metals was observed to be in the range of 230.6 ppm (Fe) to 0.3 ppm (Co) and for PAH, it was observed in the range of 612 ppm (PAH1) to 79.5 ppm (PAH10). The One-way ANOVA analysis for both the heavy metals and the PAHs showed Ho was rejected. There are significant differences in heavy metals and PAHs concentrations between sites. The selectivity sequence of heavy metals were Fe > Cr > Ni > Al > Zn > Pb > Cu. Meanwhile for PAH, the sequence is PAH1 > PAH3 > PAH2 > PAH6 > PAH5 > PAH7 > PAH4 > PAH8 > PAH9 > PAH10.

Knowledge to Ecological Preferences in a Tropical Epiphytic Algae to Use with Eutrophication Indicators

In Ayapel floodplain periphyton associated to macrophyte roots on the basis of material was collected in fourteen sampling sites in nine moments of compilation. From the analysis of the samples were recorded 550 algal species, of which 56% were diatoms. Furthermore it was valued relative abundances of taxa and the average physicochemical variables to identify the optimal values and tolerance ranges of species. In the case of nitrates optimal value was below 2 mg/L for all algae except for Actinella sp. and Euastrum sinuosum which optimal values were close to zero with low variability. Regarding all species the algal nitrite concentration showed optimum values below 2 mg/L except Encyonema minutum and E. sinuosum whose optimum were 0.4 and 0.5 mg/L respectively. About nitrogen as ammonia was repeated the above situation, i.e. optimum values below 2 mg/L except for E. minutum and E. sinuosum. Respect to phosphorus the species with optimum greater than 0.6 mg/L are the diatoms, in contrast, the lowest values were optimal for E. sinuosum and Actinella sp. From the viewpoint of bioindication high abundance of Synedra goulardii indicates high transparency, Ulnaria ulna and Planothidium lanceolatum indicate lower concentration of dissolved oxygen and water temperature between 29°C - 30°C, Actinella aff. robusta, E. minutum, Cylindrospermopsis raciborski, Lyngbya cf. limnetica, Eunotia naegueli, Navicula cryptocephala, Diadesmis confervaceae, Frustulia rhomboides and Aulacoseira granulata.(For more information,please refer to the PDF.)

Artificial Night Lighting Reduces Firefly (Coleoptera: Lampyridae) Occurrence in Sorocaba, Brazil

Artificial night lighting is gaining attention as a new type of pollution;however, studies of its impacts are scarce. Fireflies provide good models to investigate its effects on nocturnal wildlife, since they depend on their bioluminescence for reproduction. This study investigated the impact of artificial illumination on firefly activity at the new campus of the Federal University of S&atildeo Carlos (Sorocaba, Brazil). The flashing activity of different firefly species, especially Photinus sp1 (82% of all occurrences), was investigated during 3 years, before and after the installation of multi metal vapor spotlights. Quantitative and qualitative analysis, performed in transects at different distances from the artificial light sources, showed significant negative effects on Photinus sp1 occurrence. This study proposes fireflies as potential flagship species and bioindicators for artificial night lighting and for the first time quantifies its effects, providing subsidies for future conservationist legislations regarding photopollution.

Drivers of coastal bacterioplankton community diversity and structure along a nutrient gradient in the East China Sea

Anthropogenic nutrient discharge poses widespread threats to coastal ecosystems and has increased environmental gradients from coast to sea. Bacterioplankton play crucial roles in coastal biogeochemical cycling, and a variety of factors af fect bacterial community diversity and structure. We used 16 S r RNA gene pyrosequencing to investigate the spatial variation in bacterial community composition(BCC) across five sites on a coast-of fshore gradient in the East China Sea. Overall, bacterial alpha-diversity did not diff er across sites, except that richness and phylogenetic diversity were lower in the of fshore sites, and the highest alpha-diversity was found in the most landward site, with Chl-abeing the main factor. BCCs generally clustered into coastal and of fshore groups. Chl-a explained 12.3% of the variation in BCCs, more than that explained by either the physicochemical(5.7%) or spatial(8.5%) variables. Nutrients(particularly nitrate and phosphate), along with phytoplankton abundance, were more important than other physicochemical factors, co-explaining 20.0% of the variation in BCCs. Additionally, a series of discriminant families(primarily affiliated with Gammaproteobacteria and Alphaproteobacteria), whose relative abundances correlated with Chl-a, DIN, and phosphate concentrations, were identified, implying their potential to indicate phytoplankton blooms and nutrient enrichment in this marine ecosystem. This study provides insight into bacterioplankton response patterns along a coast-of fshore gradient, with phytoplankton abundance increasing in the of fshore sites. Time-series sampling across multiple transects should be performed to determine the seasonal and spatial patterns in bacterial diversity and community structure along this gradient.

Responses of terrestrial bryophytes to simulated climate change in a secondary evergreen broad-leaved forest in southern China

Tropical regions are biodiversity hotspots and are well-suited to explore the potential influence of global climate change on forest ecosystems. Bryophytes have essential ecological functions in tropical forest ecosystems, but knowledge of the potential impact of global warming and possible changes in water availability patterns on terrestrial bryophytes is limited. We transplanted eight terres- trial moss species from two elevations (900 and 500 m) to warmer and drier elevations (500 and 100 m) during a halfyear observation period on Tai Mo Shan, southern China. The simulated climate change resulted in severely declined health status and marked decrease in growth of the trans- planted species when compared with their performance at the original elevations. Five of the eight selected species survived for six months after being transplanted to the warmer and drier lowlands, though their health status deteriorated severely. Sematophyllum subhumile , Pseudotaxiphyllum pohliaecarpum and Brachythecium buchananii were highly susceptible to changes in temperature and rainfall patterns and might be used as suitable bioindicators. As the tropics are expected to become hotter and drier, terrestrial mosses might be negatively affected or even be at risk of extinction. Bryophytes in the tropics could represent one of the best biological communities to reflect the direct adverse impact of climate change and provide early warning of the biological outcomes induced by ongoing climate crisis.

Fluoride Exposure Compromises Gas Exchange of Plants

Fluorine (F-) stands out for its phytotoxic potential, because it accumulates in plants, changes enzymes activity, reduces chlorophyll content and, consequently, affects growth and yield of crop plants. An experiment was conducted to evaluate the effects of F- on leaf gas exchange in coffee and sweet orange plants, compared to sensitive (gladiolus) and tolerant (ryegrass) reference species. Plants grown in pots were exposed to F- in a semi-open mist chamber. The experimental design was completely randomized with treatments defined by the combination of plant species and two intensities of exposure to atmospheric F, with nebulization of HF solutions (low = 0.065 mmol·m-3 and high = 0.260 mmol·m-3) in a mist chamber, as well as with non-exposed control samples. CO2 assimilation (A), transpiration (E), stomatal conductance (gs) and chlorophyll fluorescence rates were measured after 27 days of treatment application. The leaf gas exchange variables in ryegrass and orange plants did not vary in response to the increase in atmospheric F, while an increase in gs and E values was observed in gladiolus and coffee plants. A decrease in A and potential quantum efficiency of photosystem II (Fv/Fm) was found for gladiolus plants. On the contrary, an increase of A for coffee plants was associated with the apparent effect previously reported about the loss of leaf stomatal regulation related to the short assessment period of plants in this experiment. Damages caused to the photosynthetic system were reflected in the susceptibility of the evaluated species to the contamination by the element.

Habitat Preference and Effects of Coastal Fragmentation in the Sand-Dwelling Spider <i>Allocosa brasiliensis</i>(Lycosidae, Allocosinae)

Allocosa brasiliensis is a sand-dwelling wolf spider considered a good bioindicator to evaluate the quality of coastal dune ecosystems from Uruguay. Habitat fragmentation and human activities have impacted and reduced the Southern Uruguayan coast during the last decades. The aim of the present study was to evaluate the density, surface activity and habitat preference of A. brasiliensis in beaches with different human impact. For that purpose, we sampled during the night with head lamps and applied the capture-mark-recapture method. Females were more abundant than males and were the most recaptured sex. The most fragmented beaches showed lower number of burrows and individuals, especially in immatures stages. We found that the most suitable sandy habitat for A. brasiliensis should present a vegetation cover optimum of 25% - 50% of the surface. This study could provide tools for the implementation of future management conservation plans of the Southern Uruguayan coastline.

Validated Method for the Detection of Three Phthalates Derived from Marine Invertebrates

This study represents, detailly, the validated method for the extraction and quantification of widespread phthalic acid esters (PAEs) bis(2-ethylhexyl) phthalate (DEHP), di-n-butyl phthalate (DBP) and di-n-octyl phthalate (DnOP) from solitary ascidians collected from a marine environment. The extraction was based on a pressurized liquid extraction method, using n-hexane as the solvent to extract the target PAEs from dry biological tissues, and was performed in an accelerated solvent extraction instrument. The average recovery of 89.2% was obtained from samples subjected to a pressure of ~1500 psi and 120°C in two 10-min cycles. GC-MS was used for quantification, conducted in single-ion monitoring mode. Following careful and rigorous cleanup procedures to prevent cross-contamination from laboratory glassware, PAE standards showed signals with good specificity. The obtained limits of detection were 130, 122 and 89 ng/g for DEHP, DBP and DnOP, respectively. Accordingly, the calculated limits of quantification were 394, 370 and 270 ng/g for DEHP, DBP and DnOP, respectively. The obtained linearity ranged from 5.4 to 269 ng/ml (equivalent to 135 - 6725 ng/g dry weight), with R2 ≥ 0.998. Concentrations in the range of 200 to 9000 and 400 to 5000 ng/g sample dry weight, for DEHP and DBP, respectively, were obtained from the ascidians. No DnOP was detected in any of the samples. These results indicate that the method presented in this study is applicable for detection of low and trace concentrations of the target PAEs in samples collected from a marine organism, which can serve as a bioindicator of plastic contamination.