Bioaccumulation and differential partitioning of polychlorinated biphenyls in freshwater, planktonic food webs

Abstract

Abstract:The planktonic food chain phytoplankton -zooplankton -young-of-the-year roach (Rutilus rutilus) was studied in 19 lakes in southern Sweden to investigate the bioaccumulation of polychlorinated biphenyls (PCBs). The SPCB concentrations did not steadily increase with increasing trophic level. The SPCB concentrations in zooplankton (400 ng·g lipid -1 ) were lower than in both phytoplankton (660 ng·g lipid -1 ) and fish (890 ng·g lipid -1 ), which did not differ significantly. Lipid content explained 40% of the total variation in dry weight normalised SPCB concentrations in the samples. The PCBs were differentially partitioned between the trophic levels. The logBMFs (biomagnification factors, concentration in predator/concentration in prey) were a function of the logK ow of the PCB congeners. The logBMF zoo/phyto values were < 0 for all PCB congeners on a lipid weight basis, and the logBMF fish/zoo values were < 0 for PCB congeners with logK ow > 6. We conclude that no PCBs had higher lipid-normalised concentrations in zooplankton than in phytoplankton and the most lipophilic PCBs had moderately higher concentrations in roach than in zooplankton. PCBs with logK ow > 6 decreased in concentration from phytoplankton to zooplankton to roach. We suggest that the concept of biomagnification did not apply to the planktonic food chain investigated in these lakes.Résumé : Nous avons étudié la chaîne alimentaire planctonique phytoplancton -zooplancton -jeune gardon (Rutilus rutilus) dans 19 lacs du sud de la Suède afin d'analyser la bioaccumulation des polychlorobiphényles (PCB). Les concentrations de SPCB n'ont pas augmenté de façon constante avec l'augmentation du niveau trophique. Les concentrations de SPCB dans le zooplancton (400 ng·g lipides -1 ) étaient plus faibles que dans le phytoplancton (660 ng·g lipides -1 ) et chez les poissons (890 ng·g lipides -1 ), concentrations qui ne différaient pas de façon significative. La teneur en lipides expliquait 40% de la variation totale des concentrations normalisées de SPCB en poids sec dans les échantillons. Les PCB étaient répartis de façon différentielle entre les niveaux trophiques. Le log FBA (facteurs de bioamplification, concentration chez le prédateur/concentration chez les proies) était une fonction du log K ow des congé-nères de PCB. Le log FBA zoo/phyto était < 0 pour tous les congénères de PCB en fonction du poids en lipides, et le log FBA poisson/zoo était < 0 pour les congénères de PCB dont le log K ow > 6. Nous concluons qu'aucun PCB n'avait une concentration normalisée dans les lipides plus élevée chez le zooplancton que chez le phytoplancton, et que les concentrations de PCB les plus lipophiles étaient modérément plus élevées chez le gardon que chez le zooplancton. On observait une diminution de la concentration de PCB dont le log K ow > 6 en passant du phytoplancton au zooplancton puis au gardon. La notion de bioamplification ne semblait donc pas s'appliquer aux organismes de la chaîne alimentaire planctonique étudiés dans ces lacs.[Traduit par la Réd...

An exploration of the role of mysids in benthic‐pelagic coupling and biomagnification using a dynamic bioaccumulation model

“…These values are within 15 nPa of those predicted by the model of Fraser et al [22]. This suggests that the lipid fraction largely accounts for the measured bioaccumulation, consistent with the findings of Berglund et al [34]. 4) now follows the lipid fraction curve shown in Figure 2b.…”

“…Adare and Lasenby [33] suggest that the gender of a mysid also plays a role in the lipid content with mature mysids having a lipid content of 15 to 33% for females and 14 to 25% for males [33]. Berglund et al [34] suggested that lipid content explains 40% of the total variation in dry weight-normalized total PCB concentrations in samples from planktonic food chains, and Harding [35] suggested more generally that increases in lipid content in mysids and other zooplankton because of seasonal and size variations in the organism may increase organic contaminant concentrations. Berglund et al [34] suggested that lipid content explains 40% of the total variation in dry weight-normalized total PCB concentrations in samples from planktonic food chains, and Harding [35] suggested more generally that increases in lipid content in mysids and other zooplankton because of seasonal and size variations in the organism may increase organic contaminant concentrations.…”

The Effect of Lake Trophy on Lipid Content and PCB Concentrations in Planktonic Food Webs

“…Therefore, increased prey availability may permit zooplankton in eutrophic lakes to obtain the same amount of dietary lipids despite lower food quality of the individual phytoplankton. Also, it seems that there is no food chain biomagnification of PCBs in these planktonic food chains (Berglund et al 2000), so possible differences in phytoplankton PCB concentrations due to different trophic status may not be reflected in herbivores or consumers higher up in the food chain (Fig. This could have implications on the PCB accumulation in zooplankton.…”

Partitioning of polychlorinated biphenyls between Arctic seawater and size‐fractionated zooplankton

“…However, those authors demonstrated a drastic decrease of the slope above a log K OW of six in the log‐log plot between the lipid‐normalized partition coefficient and K OW , and they interpreted this as biodilution in the zooplankton. Linear log K –log K OW relationships in zooplankton also have been reported, however, displaying slopes deviating from one [11]. Other investigators, based on PCB concentrations in zooplankton and prey, concluded that biomagnification did not have a significant effect on PCB concentrations in zooplankton.…”