Top predators and scavengers are vulnerable to pollutants, particularly those accumulated along the food chain. Lead accumulation can induce severe disorders and alter survival both in mammals (including humans) and in birds. A potential source of lead poisoning in wild animals, and especially in scavengers, results from the consumption of ammunition residues in the tissues of big game killed by hunters. For two consecutive years we quantified the level lead exposure in individuals of a sentinel scavenger species, the common raven (Corvus corax), captured during the moose (Alces alces) hunting season in eastern Quebec, Canada. The source of the lead contamination was also determined using stable isotope analyses. Finally, we identified the different scavenger species that could potentially be exposed to lead by installing automatic cameras targeting moose gut piles. Blood lead concentration in ravens increased over time, indicating lead accumulation over the moose-hunting season. Using a contamination threshold of 100 µg.L−1, more than 50% of individuals were lead-contaminated during the moose hunting period. Lead concentration was twice as high in one year compared to the other, matching the number of rifle-shot moose in the area. Non-contaminated birds exhibited no ammunition isotope signatures. The isotope signature of the lead detected in contaminated ravens tended towards the signature from lead ammunition. We also found that black bears (Ursus americanus), golden eagles and bald eagles (Aquila chrysaetos and Haliaeetus leucocephalus, two species of conservation concern) scavenged heavily on moose viscera left by hunters. Our unequivocal results agree with other studies and further motivate the use of non-toxic ammunition for big game hunting.

Tetrabromobisphenol A (4,4'-isopropylidenebis(2,6-dibromophenol), TBBPA) is the most widely used brominated flame retardant in the world. Due to its low water solubility TBBPA released in aquatic ecosystems ultimately accumulates in sediments, but the lack of data on its environmental level and temporal trend in sediment cores precludes establishing if the input of TBBPA is an on-going environmental problem. We developed an analytical method involving HPLC-ESI-MS-MS (ion trap) with detection of the negative pseudo-molecular ion of TBBPA and its fragmentation pattern. Recovery of TBBPA from spiked marine sediment (both lyophilized and wet) and dehydrated sewage sludge was better than 95%. The current detection limit of TBBPA is 60 pg injected and the linearity of the response is at least three orders of magnitude, ranging from 7 ng ml(-1) to 7000 ng ml(-1). The method was also applied to the analysis of urban sewage sludge where TBBPA was detected at a concentration of 300 ng g(-1)(dry weight). With an analysis time of less than 20 min, this method is adequate for a rapid re-assessment of archived sediment samples avoiding cumbersome derivatization procedures.

Protein hydrolysates were prepared from echinoderm byproducts, including viscera (SCV) of Atlantic sea cucumber (Cucumaria frondosa) and digestive tract (UDT) and non-commercial grade gonads (UGN) of green sea urchin (Strongylocentrotus droebachiensis). Enzymatic hydrolysis was performed on defatted materials using Alcalase Ò 2.4L (0.75% w ⁄ w) and reaction was carried out overnight ($16 h, 55°C, pH 8.0). Freeze-dried hydrolysates were analysed for their nutritional composition, nitrogen solubility index and antioxidant activity. Degree of hydrolysis was low, with values of 5.6%, 4.6% and 7.0% for SCV, UDT and UGN, respectively. Hydrolysates showed high protein content ($55%), high proportion of essential amino acids ($35% of total amino acids) and good solubility (nitrogen solubility index % 68%). They contained variable concentrations of major and trace elements with a predominance of Na and K. Hydrolysates showed apparent antioxidant activities in both ORAC assay (267-421 lmol TE g )1 ) and inhibition of lipid oxidation test (54-57%). Antioxidant activities were thought to be associated with the presence of antioxidant peptides in hydrolysates. Our results showed that hydrolysates from Atlantic sea cucumber and green sea urchin byproducts might serve as alternative sources of dietary proteins, with good nutritional composition, high solubility and interesting protection against oxidative stress.

No abstract