PCB Levels and Accumulation Patterns in Waterbird Eggs and in Their Prey at Lake Kerkini, a North-Eastern Mediterranean Wetland of International Importance

Abstract

Seven "target" PCB levels were determined and compared in waterbird eggs, in their prey, and in water at Lake Kerkini, northern Greece, to investigate PCB bioaccumulation patterns and to define the best bioindicator of target PCBs for this area. PCBs were analysed from eggs of Phalacrocorax carbo, Podiceps cristatus, Ardea cinerea, Egretta garzetta, and Nycticorax nycticorax and from prey types Alburnus alburnus, Rutilus rutilus, Lepomis gibbosus. Carassius auratus, and Rana sp. PCBs analysed were detected in all bird eggs, prey, and water but contamination patterns differed among these sample types. The lipid-corrected geometric means of the congeners analysed were significantly different among most bird species and among some prey species. PCB congeners 118, 138, 153, and 180 accounted for around 80% of the total PCB contamination in bird egg samples. Percent congener concentrations of high-chlorinated PCBs tended to increase from water through prey to most bird egg samples whereas the low chlorinated PCBs (28 and 52) decreased. Bioaccumulation factors (BAFs) also exhibited an increasing trend for higher chlorinated PCBs from prey types to bird eggs. The greatest BAFs of six of the congeners were shared between Phalacrocorax carbo and Ardea cinerea. Among prey, the BAFs of four PCBs were highest in Lepomis gibbosus. Biomagnification factors varied between 1.01 and 39.57. In contrast to low chlorinated PCBs, high chlorinated congeners biomagnified considerably through fish prey. The highest biomagnification took place in Phalacrocorax carbo. No relationship was found between the lipid content of samples and BAFs of PCBs probably due to biotransformation differences of the congeners in the biota sampled. Due to the greatest PCB concentrations especially of the higher chlorinated PCBs in the eggs of Phalacrocorax carbo and its considerable bioaccumulation tendencies, it is proposed as the best PCB biomonitor of target PCBs at Lake Kerkini. Lepomis gibbosus had the highest concentrations of most congeners and exhibited the greatest bioaccumulative properties among prey and can be used as an alternative biomonitor.

Migration and Opportunistic Feeding Increase PCB Accumulation in Arctic Seabirds

“…The effect of the log K ow on the log body concentration was linear for log K ow values below 7, while for higher log K ow values the slope of the smoother decreases (Figure ). This shape is in accordance with previous findings − and can be explained by reduced assimilation of highly lipophilic congeners …”

Organochlorine pesticides and polychlorinated biphenyls in carnivorous waterbird species from Lake Ziway, Ethiopia

“…The order of mean concentrations of PCB congeners from high to low was as follows: PCB-153 (3.0 ng g −1 ) > PCB-138 (1.3 ng g −1 ) > PCB-180 (1.1 ng g −1 ) > PCB-118 (0.8 ng g −1 ) > PCB-101 (0.2 ng g −1 ) > PCB-52 (ND) & PCB-26 (ND). The aforementioned order could be attributed to differences in chlorine content, lipophilic property, and biomagnification capacity among the congeners [50]. The present finding is in concordance with the order of congeners that was found in the eggs of Northern gannets (Morus bassanus) [51].…”

“…Various sublethal effects have been associated with PCB exposure [50]. PCBs toxicities were linked to decreased nest attentiveness [6], disruption of feather coloration [7], and impairment of sound production in birds [8] that may culminate in an impairment of reproductive behaviors.…”

Standardization of Egg Collection from Aquatic Birds for Biomonitoring - A Critical Review

“…Nevertheless, in most papers, no information is provided about packing for transport (78%). Padded containers or egg cartons, which are suitable to prevent egg breakage, were used in six studies (7%). ,,,,, Aluminum foil, chemically cleaned glass jars, and Ziploc bags, which are also used for packing, cannot effectively protect the eggs against breakage during transport.…”

“…Eggs from aquatic birds are commonly used in biomonitoring as reliable indicators of pollution − because these birds tend to occupy upper trophic levels and thus accumulate a wide range of contaminants.…”