Affiner votre recherche
Résultats 1-4 de 4
Tuna and dolphin associations in the Northeast Atlantic: Evidence of different ecological niches from stable isotope and heavy metal measurements
2000
Das, Krishna | Lepoint, Gilles | Loizeau, Véronique | Debacker, Virginie | Dauby, Patrick | Bouquegneau, Jean-Marie
peer reviewed | Associations of tunas and dolphins in the wild are quite frequent events and the question arises how predators requiring similar diet in the same habitat share their environmental resources. As isotopic composition of an animal is related to that of its preys, stable isotopes (13C/12C and 15N/14N) analyses were performed in three predator species from the Northeast Atlantic: the striped dolphin, Stenella coeruleoalba, the common dolphin Delphinus delphis, and the albacore tuna, Thunnus alalunga, and compared to their previously described stomach content. Heavy metals (Cd, Zn, Cu and Fe) are mainly transferred through the diet and so, have been determined in the tissues of the animals. Tunas muscles display higher delta15N than in common and striped dolphins (mean: 11.4 0/00 vs. 10.3 0/00 and 10.4 0/00, respectively) which reflects its higher trophic level nutrition. Higher delta13C are found in common (-18.4 0/00) and striped dolphin (-18.10/00) muscles than in albacore tuna (-19.3 0/00) likely in relation with its migratory pattern. The most striking feature is the presence of two levels of cadmium concentrations in the livers of the tunas (32 mg kg-1 dry weight vs. 5 mg kg-1 dry weight). These two groups also differ by their iron concentrations and their delta15N and delta 13C liver values. These results suggest that in the Biscay Bay, tunas occupy two different ecological niches likely based on different squid input in their diet.
Afficher plus [+] Moins [-]Determination of organohalogenated contaminants in liver of harbour porpoises (Phocoena phocoena) stranded on the Belgian North Sea coast
2002
Covaci, Adrian | Van de Vijver, Kristin Inneke | De Coen, Wim | Das, Krishna | Bouquegneau, Jean-Marie | Blust, Ronny | Schepens, Paul | MARE - Centre Interfacultaire de Recherches en Océanologie - ULiège
peer reviewed
Afficher plus [+] Moins [-]Baseline study of perfluorochemicals in harbour porpoises (Phocoena phocoena) from Northern Europe
2004
Van de Vijver, Kristin Inneke | Hoff, P. T. | Das, Krishna | Van Dongen, Walter | Esmans, Eddy Louis | Siebert, Ursula | Bouquegneau, Jean-Marie | Blust, Ronny | De Coen, Wim | MARE - Centre Interfacultaire de Recherches en Océanologie - ULiège
peer reviewed | Marie-Curie Fellowship
Afficher plus [+] Moins [-]Investigation of microplastic pollution in Arctic fjord water: a case study of Rijpfjorden, Northern Svalbard
2022
Bao, Mengrong | Huang, Qinghui | Lu, Zhibo | Collard, France | Cai, Minggang | Huang, Peng | Yu, Yong | Cheng, Shuiping | An, Lihui | Wold, Anette | Gabrielsen, Geir Wing
peer reviewed | Microplastic contamination is an emerging issue in the marine environment including the Arctic. However, the occurrence of microplastics in the Arctic fjords remains less understood. Sample collections were conducted by trawling horizontally in surface water (0-0.4-m depth) and trawling vertically in the water column (0-200-m depth) to investigate the abundance, composition, and distribution of microplastics in the Rijpfjorden, Northern Svalbard, in the summer of 2017. Laser Direct Infrared chemical imaging technique was applied for the counting and identification of microplastic particles. A total of 1010 microplastic particles and 14 mesoplastics were identified from 41,038 particles in eight samples from the Rijpfjorden. The abundance of microplastics larger than 300 µm was 0.15 ± 0.19 n/m3 in surface water, and 0.15 ± 0.03 n/m3 in the water column of the Rijpfjorden. The microplastic particles identified in Rijpfjorden water consisted of 10 types of polymers. The dominant microplastics are polyurethane, polyethylene, polyvinyl acetate, polystyrene, polypropylene, and alkyd varnish. Historical ship activities and newly melted sea ice might be major sources of microplastics in the seawater of Rijpfjorden. In general, contamination of microplastics larger than 300 µm in Rijpfjorden water is at a low level in comparison to other polar waters. Further research is needed to confirm the origin and fate of microplastics below 300 µm in Arctic fjords.
Afficher plus [+] Moins [-]