17 research outputs found
Occurrence and distribution of anthropogenic persistent organic pollutants in coastal sediments and mud shrimps from the wetland of central Taiwan
Sediment profile and mud shrimp (Austinogebia edulis) from the coastal wetland of central Taiwan in 2017 and 2018 were analyzed for concentration, source, and composition of persistent organic pollutants (POPs) including polycyclic aromatic hydrocarbon (PAHs), polybrominated diphenyl ethers (PBDEs), organochlorine pesticides (OCPs; DDT and HCB), and polychlorinated biphenyls (PCBs). Sediment profiling indicated PAH concentrations reaching 254.38 ng/g dw in areas near industrial areas and PAH concentrations of 41.8 and 58.42 ng/g dw in sampling areas further from industrial areas, suggesting that the determining factor for spatial distribution of POPs might be proximity to contaminant sources in industrial zones. Based on molecular indices, PAHs were substantially of both pyrolytic and petrogenic origins. The main sources for PCBs were Aroclor 1016 and 1260 and the congener BDE-209 was the dominant component among PBDE congeners. While we were unable to obtain live mud shrimp samples from the heavily contaminated areas, in samples from less contaminated areas, the risk assessment on mud shrimp still illustrated a borderline threat, with DDT concentrations almost reaching standardized values of Effects Range-Low (ERL). Bioaccumulation factors for DDTs and PCBs (17.33 and 54.59, respectively) were higher than other POPs in this study. Further study is essential to assess and understand the impact of these chemicals on the wetland ecosystem near this heavily industrialized area.Fil: Das, Shagnika. National Taiwan Ocean University; RepĂșblica de China. Universite Lille; Francia. University Littoral Cote dâOpale; FranciaFil: Arias, Andres Hugo. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - BahĂa Blanca. Instituto Argentino de OceanografĂa. Universidad Nacional del Sur. Instituto Argentino de OceanografĂa; Argentina. Universidad Nacional del Sur. Departamento de QuĂmica; ArgentinaFil: Cheng, Jing O.. National Museum of Marine Biology and Aquarium; RepĂșblica de ChinaFil: Souissi, Sami. Universite Lille; Francia. University Littoral Cote dâOpale; FranciaFil: Hwang, Jiang Shiou. National Taiwan Ocean University; RepĂșblica de ChinaFil: Ko, Fung Chi. National Dong Hwa University; RepĂșblica de Chin
Effets des facteurs environnementaux sur lâĂ©cophysiologie et les traits vitaux dâun macro-crustacĂ© (crevette) et dâun micro-crustacĂ© (copĂ©pode)
La prĂ©sente thĂšse comprend deux grandes sections, la premiĂšre traitant des macro-crustacĂ©s, la crevette de vase Austinogebia edulis et la seconde des micro-crustacĂ©s, le copĂ©pode Eurytemora affinis. Les objectifs Ă©taient de 1. Explorer le rĂŽle dâA. edulis en tant quâingĂ©nieur Ă©cologique, 2. Effets du Cd sur les enzymes oxydatives et la morphologie dâA. edulis, 3. Ăvaluer la variation spatiale et temporelle des polluants organiques persistants (POP) dans lâhabitat naturel dâA. edulis, 4. Explorer lâeffet dâun cocktail de 4 mĂ©taux lourds sur E. affinis et dĂ©crire lâeffet des sĂ©diments en suspension sur E. affinis en suivant une approche multigĂ©nĂ©rationnelle. Pour le premier objectif, nous soulignons les diffĂ©rences significatives entre les murs des terriers et les lumens. La paroi du terrier dâA. edulis prĂ©sentait une faible permĂ©abilitĂ© et augmentait la rĂ©sistance. Statistiquement, on a remarquĂ© une diffĂ©rence importante dans la comparaison entre la composition des sĂ©diments de la paroi du terrier et le fond. La paroi du terrier se composait dâune teneur en matiĂšre organique 24 fois supĂ©rieure Ă celle dâun individu de crevette. Ainsi, ils transforment les caractĂ©ristiques des sĂ©diments en tant quâingĂ©nieur Ă©cologique, ce qui devrait avoir un impact Ă©cologique important sur lâĂ©cosystĂšme. De plus, lors de lâexposition au Cd, les activitĂ©s des enzymes antioxydantes (SOD, CAT et GPx) diminuaient avec lâaugmentation de la concentration de Cd et le temps dâexposition prolongĂ© dans ces organes de la crevette A. edulis. Des dommages importants de lâhĂ©patopancrĂ©as dâA. edulis ont Ă©tĂ© remarquĂ©s Ă des concentrations plus Ă©levĂ©es de Cd, montrant des dommages comme la disparition des limites des cellules Ă©pithĂ©liales, le dĂ©tachement des cellules de la lamine basale, gonflement cellulaire, nĂ©crose, etc. En conclusion, le Cd a causĂ© des dommages oxydatifs en rĂ©duisant les activitĂ©s des enzymes antioxydantes et en endommageant la structure tissulaire dans les principaux organes de la crevette A. edulis. Pour les POP mesurĂ©s, la distribution spatiale a montrĂ© que la proximitĂ© des sources pollution Ă©tait le plus important facteur dĂ©terminant pour la distribution de ces contaminants, montrant des concentrations plus Ă©levĂ©es dans les Ă©chantillons prĂ©levĂ©s prĂšs des parcs industriels. Les rapports des HAP analysĂ©s ont permis de dĂ©terminer lâexistence dâintrants pyrolytiques et pĂ©trogĂ©niques. Les PCB Aroclor 1016 et 1260 Ă©taient les principales sources prĂšs de la zone industrielle, avec des entrĂ©es de DDT montrant un ajout rĂ©cent Ă la zone. LâĂ©tude globale a rĂ©vĂ©lĂ© un risque limite pour les organismes benthiques. Dans le cas dâE. affinis, la toxicitĂ© aiguĂ« de CL 50 % (96h) pour lâexposition au plomb (Pb) Ă©tait de 431,99 ”g/l chez les mĂąles prĂ©sentant une sensibilitĂ© infĂ©rieure Ă celle des femelles avec 394,27 ”g/l. Les plus faibles effectifs totaux de la population ont Ă©tĂ© observĂ©s durant la deuxiĂšme gĂ©nĂ©ration (F1) pour tous les traitements dâexposition et, par consĂ©quent, la mortalitĂ© a augmentĂ© dans cette gĂ©nĂ©ration. La plus forte bioaccumulation des mĂ©taux dans le copĂ©pode E. affinis Ă©tait Ă©galement plus Ă©levĂ©e dans cette gĂ©nĂ©ration ; la fĂ©conditĂ© et la survie semblaient donc liĂ©es Ă la bioaccumulation des mĂ©taux lourds et concluaient que la sensibilitĂ© ou la fitness dâE. affinis Ă©tait directement liĂ©e Ă lâaccumulation de mĂ©taux traces. Le pourcentage de mĂąles Ă©tait moins Ă©levĂ© dans le traitement des sĂ©diments que dans celui des mĂ©taux lourds et des tĂ©moins. Cette observation peut indiquer lĂ©gĂšrement les diffĂ©rentes façons dont les copĂ©podes sont sensibles aux mĂ©taux lourds et aux sĂ©diments en suspension lorsquâils sont exposĂ©s pendant plusieurs gĂ©nĂ©rations.The present thesis constitutes two major sections, the first deals with macro crustaceans, mud shrimp Austinogebia edulis and the second with micro crustaceans, the copepod Eurytemora affinis. The objectives were to 1. Explore the role of A. edulis as an ecological engineer, 2. Effects of Cadmium (Cd) on oxidative enzymes and morphology in A. edulis, 3. To assess the spatial and temporal variation of persistent organic pollutants (POPs) in the natural habitat of A. edulis, 4. To explore the effect of combined heavy metals to E. affinis and to depict the effect of sediment in re-suspension to E. affinis by following a multigenerational approach. For the first objective, we highlight the significant differences between burrow walls and burrow lumen. The burrow wall of A. edulis showed low permeability and increased sheer strength. Statistically, a significant difference was noticed in the comparison between the sediment composition of the burrow wall and the background. The burrow wall consisted of a 24 times higher organic matter content than one individual of mud shrimp. Thus, they transform the sediment characteristics as an ecological engineer, which is expected to have a significant ecological impact on the ecosystem. Furthermore, on exposure to Cd the antioxidant enzyme (SOD, CAT, and GPx) activities decreased with increasing Cd concentration and extended exposure time in these organs of A. edulis. Significant damage of the hepatopancreas of A. edulis was noticed at higher concentrations of Cd, showing damages like the disappearance of epithelial cell boundaries, detachment of cells from the basal lamina, cellular swelling, necrosis, etc. In conclusion, Cd caused oxidative damage by reducing the activities of antioxidant enzymes and by damaging the tissue structure in major organs of A. edulis. For the measured POPs, the spatial distribution showed that the proximity to sources was the most important determining factor for the distribution of these contaminants showing greater concentrations in samples collected near the industrial parks. The analyzed PAH ratios determined an existence of both pyrolytic and petrogenic inputs. PCBs Aroclor 1016 and 1260 were the main sources near the industrial zone, with DDT inputs showing recent addition to the area. The overall study reflected a borderline risk to the benthic organisms. For E. affinis, the acute toxicity LC 50% (96h) for the exposure of Lead (Pb) was found to be 431.99 ”g/l for males showing lower sensitivity than females with 394.27 ”g/l. The total population became lowest in the 2nd generation (F1) for all the exposure treatments and also the mortality increased in this generation. The bioaccumulation of metals in the copepod E. affinis was also higher in this generation; thereby fecundity and survival appeared to be linked to the bioaccumulation of heavy metals and concluding that the sensitivity or fitness of E. affinis was directly connected to the trace metal accumulation. The percentage of males was less in the sediment treatment than the heavy metal and control. This observation can slightly indicate the different ways of copepod sensitivity to heavy metals and sediment in re-suspension when exposed for multiple generations
Responses of the copepod Eurytemora affinis to trace metal exposure: A candidate for sentinel to marine sediment resuspension effects
International audienc
Single toxicity of arsenic and combined trace metal exposure to a microalga of ecological and commercial interest: Diacronema lutheri
International audienc
Burrow characteristics of the mud shrimp Austinogebia edulis, an ecological engineer causing sediment modification of a tidal flat.
The mud shrimp Austinogebia edulis, being abundant in the intertidal zone of western Taiwan, constructs deep burrows (>1 m). This study highlights the potential of mud shrimps to modify sediment characteristics of the tidal flat by its burrowing behavior. We studied the structure of the burrow wall, compared the difference in the sediment composition of the burrow and the background sediment, and compared the organic content inside the burrow wall. This study was carried out from September 2015 to November 2016 in three areas of the western coast of Taiwan, namely Shengang, Hanbow, and Wangong. The present study found significant differences between burrow wall and the burrow lumen. The diameter of the burrow wall was double as wide as the inner burrow lumen at the opening and gradually increased to 10 times of the burrow lumen at 30 cm depth. The burrow wall of A. edulis showed low permeability and increased the sheer strength. Statistically, a significant difference was noticed in the comparison between the sediment composition of the burrow wall and the background (p < 0.05, Student's t-test). An accumulation of 3.63 for fine sand (t = -5.22, p < 0.001, fine sand) and 9 for clay (t = -25.01, p < 0.001, clay) was found in the upper burrow wall of A. edulis. This indicated that they somehow chose finer particles to build burrows. This will gradually change the sediment distribution-vertically and horizontally. The burrow wall consisted of a 24 times higher organic matter content than one individual of mud shrimp. The burrow may provide organic material as a potential food source. The mud shrimp thus transforms the sediment characteristics as an ecological engineer, which is expected to have a significant ecological impact on the ecosystem
Trace metals exposure in three different coastal compartments show specific morphological and reproductive traits across generations in a sentinel copepod
International audienceThe effect of exposure from several compartments of the environment at the level of individuals was rarely investigated. This study reports the effect of contaminants from varied compartments like sediment resuspension, elutriation from resuspended sediment (extract) and seawater spiked trace metal mixtures (TM) on morphological and reproductive traits of the pelagic bioindicator copepod Eurytemora affinis. At the population level of E. affinis, lowest survival was observed in dissolved exposures (TM and extract) in the first generation (G1), showing some adaptation in the second generation (G2). An opposite trend for resuspended sediment showed higher sensitivity in survival at G2. At the individual level, prosome length and volume proved to be sensitive parameters for resuspended sediments, whereas clutch size and egg diameter were more sensitive to TM and extract. Although the generation of decontamination (G3, no exposure), showed a significant recovery at the population level (survival % along with clutch size) of E. affinis exposed to resuspended sediment, morphological characteristics like prosome length and volume showed no such recovery (lower than control, p < 0.05). To the contrary, dissolved exposure showed no significant recovery from G1 to G3 on neither survival %, clutch size, egg diameter, prosome volume, but an increase of prosome length (p < 0.05). Such tradeoffs in combatting the stress from varied sources of toxicity were observed in all exposures, from G1 to G3. The number of lipid droplets inside the body cavity of E. affinis showed a significant positive correlation with trace metal bioaccumulation (p < 0.01) along with a negative correlation (p < 0.05) with survival and clutch size in each treatment. This confirms the inability of copepods to utilize lipids under stressful conditions. Our study tenders certain morphological and reproductive markers that show specificity to different compartments of exposure, promising an advantage in risk assessment and fish feed studies
Assessing indicators of arsenic toxicity using variable fluorescence in a commercially valuable microalgae: Physiological and toxicological aspects
International audienceIndicators signaling Arsenic (As) stress through physiology of microalgae using non-destructive methods like variable fluorescence are rare but requisite. This study reports stress markers indicating arsenic (As) toxicity (in two concentrations 11.25 ”g/L and 22.5 ”g/L compared to a control) exposed to a microalga (Diacronema lutheri), using fast repetition rate fluorometry (FRRf). Growth and physiological parameters such as cell density, chl a and the maximum quantum yield Fv/Fm showed coherence and impeded after the exponential phase (day 9 - day 12) in As treatments compared to the control (p < 0.05). On contrary photo-physiological constants were elevated showing higher optical (aLHII) and functional [Sigma (ÏPSII)] absorption cross-section for the As treatments (p < 0.05) further implying the lack of biomass production yet an increase in light absorption. In addition, As exposure increased the energy dissipation by heat (NPQ-NSV) showing a strong relationship with the de-epoxidation ratio (DR) involving photoprotective pigments. Total As bioaccumulation by D. lutheri showed a strong affinity with Fe adsorption throughout the algal growth curve. This study suggests some prompt photo-physiological proxies signaling As contamination and endorsing its usefulness in risk assessments, given the high toxicity and ubiquitous presence of As in the ecosystem
Results of Studentâs t-test comparison for proportion (%) of each size category of sediment between habitat (control) and burrow.
<p>Results of Studentâs t-test comparison for proportion (%) of each size category of sediment between habitat (control) and burrow.</p
Comparison of the void ratio of the mud shrimp burrow wall and the ambient sediment in 3 sampling areas; (a) comparison of ash free dry weight of background sediment and mud shrimp burrow wall using one-way analysis of variance, followed by Tukeyâs test; (b) relative weight of ash-free dry weight of one individual of mud shrimp and one whole mud shrimp burrow wall (c).
<p>Comparison of the void ratio of the mud shrimp burrow wall and the ambient sediment in 3 sampling areas; (a) comparison of ash free dry weight of background sediment and mud shrimp burrow wall using one-way analysis of variance, followed by Tukeyâs test; (b) relative weight of ash-free dry weight of one individual of mud shrimp and one whole mud shrimp burrow wall (c).</p
Burrow characteristics of the mud shrimp <i>Austinogebia edulis</i>, an ecological engineer causing sediment modification of a tidal flat
<div><p>The mud shrimp <i>Austinogebia edulis</i>, being abundant in the intertidal zone of western Taiwan, constructs deep burrows (>1 m). This study highlights the potential of mud shrimps to modify sediment characteristics of the tidal flat by its burrowing behavior. We studied the structure of the burrow wall, compared the difference in the sediment composition of the burrow and the background sediment, and compared the organic content inside the burrow wall. This study was carried out from September 2015 to November 2016 in three areas of the western coast of Taiwan, namely Shengang, Hanbow, and Wangong. The present study found significant differences between burrow wall and the burrow lumen. The diameter of the burrow wall was double as wide as the inner burrow lumen at the opening and gradually increased to 10 times of the burrow lumen at 30 cm depth. The burrow wall of <i>A</i>. <i>edulis</i> showed low permeability and increased the sheer strength. Statistically, a significant difference was noticed in the comparison between the sediment composition of the burrow wall and the background (<i>p</i> < 0.05, Studentâs t-test). An accumulation of 3.63 for fine sand (t = -5.22, <i>p</i> < 0.001, fine sand) and 9 for clay (t = -25.01, <i>p</i> < 0.001, clay) was found in the upper burrow wall of <i>A</i>. <i>edulis</i>. This indicated that they somehow chose finer particles to build burrows. This will gradually change the sediment distributionâvertically and horizontally. The burrow wall consisted of a 24 times higher organic matter content than one individual of mud shrimp. The burrow may provide organic material as a potential food source. The mud shrimp thus transforms the sediment characteristics as an ecological engineer, which is expected to have a significant ecological impact on the ecosystem.</p></div