José Vingada

Trace element concentrations in Proteocephalus macrocephalus (Cestoda) and Anguillicola crassus (Nematoda) in comparison to their fish host, Anguilla anguilla in Ria de Aveiro, Portugal.

The use of some fish parasites as bioindicators of heavy metal pollution has been demonstrated as particularly adequate due to their capacity of bioconcentration. This study evaluated the effect of Proteocephalus macrocephalus on the accumulation of trace elements in the edible fish, Anguilla anguilla, in a contaminated area in Portugal (Ria de Aveiro). Also, the model P. macrocephalus/A. anguilla was assessed as a bioindicator system in the presence of the highly prevalent nematode Anguillicola crassus. Samples (kidney, liver, muscle, A. crassus and P. macrocephalus) of 20 eels harbouring A. crassus and another 20 harbouring both A. crassus and P. macrocephalus were selected for element analysis by ICP-MS. The highest concentrations of Cr, Ni and Zn were detected in P. macrocephalus. However, there was a higher liver and muscle Cr concentration in eels not infected by P. macrocephalus. Also, the nematode A. crassus presented higher Cr concentrations in those eels harbouring P. macrocephalus. Results suggest that P. macrocephalus individuals accumulate Cr and Ni while levels of Cr in eel livers and Ni levels in eel kidney are reduced. The system P. macrocephalus/A. anguilla yielded bioaccumulation factors for Cr, Ni, Pb and Zn, whereas bioaccumulation of Cu, Cr and Pb in A. crassus varied according to eel co-infection with P. macrocephalus, thus emphasising the possible role of cestode infection in metal metabolization/storage processes in host tissues. Results suggest that heavy metal pollution in Ria de Aveiro has been decreasing although it is still higher than in other contaminated areas in Europe. Nevertheless, eel consumption in Ria de Aveiro represents no risk for humans although they may represent a real contamination risk for wildlife. The system P. macrocephalus/A. anguilla is proposed as another promising bioindicator system to evaluate environmental Cr, Ni, Pb and Zn exposure in estuarine areas where both species co-occur.

Toxic Element Concentrations in the Razorbill Alca torda (Charadriiformes, Alcidae) in Portugal

The present study provides the first data on inorganic element levels (As, Cd, Co, Cr, Cu, Hg, Mn, Pb, Se, and Zn) in juvenile, immature, and adult razorbills (Alca torda) collected along the central coast of Portugal. Element concentrations were assessed by ICP-MS in kidney, liver, muscle, and feathers of 28 razorbills, including 4 juveniles, 17 subadults, and 7 adults. The effect of age and tissue on element accumulation was also assessed. The detected levels in razorbills may indicate a possible contamination risk by Hg and Cr. With respect to bird tissues, higher accumulation of Se and Cd was detected in kidney, Zn and Pb in feathers, and As and Mn in liver. Age was found to affect the accumulation of Cd, Cr, Cu, Hg, and Mn, juveniles presenting higher levels of Cu and Mn than older individuals. In razorbill kidney, Zn–Hg constituted the most significant relationship among metal concentrations. Liver presented the highest number of significant relationships (mostly involving Zn and Co). With regard to feathers, the most significant relationships involved Se, Zn, Cr and Cu concentrations. Positive linear relationships were detected among kidney, liver, and muscle, with emphasis on relationships involving Se and Hg, which may be indicative of similar accumulation/regulation mechanisms in those organs. Element concentrations are discussed in view of possible detoxification mechanisms in seabirds.

Assessing heavy metal pollution using Great Tits (Parus major): feathers and excrements from nestlings and adults

Passerine species have been increasingly used as bioindicators of metal bioaccumulation especially by taking benefit of non-invasive procedures, such as collecting feathers and excrements. In 2009, metal (As, Cd, Cu, Hg, Ni, Pb, Se and Zn) concentrations were determined in feathers and excrements of nestling and adult female great tits (Parus major) in industrial (a paper mill) and rural sites in maritime pine forests on the west coast of Portugal. The aim of this study was to compare the levels of metals between the areas but also between sampling methods (feather vs. excrement) and age classes (nestling vs. adult). Although excrements and feathers of nestling great tits showed different concentrations, similar patterns of accumulation were detected in both study areas. There was a significantly higher concentration of mercury in the industrial area and significantly higher concentrations of arsenic in the rural area in both sample types. Metal levels in adult females had quite different results when compared to nestlings, and only nickel presented significantly higher levels near the paper mill. Since metal levels showed a consistent pattern in feathers and excrements of nestling great tits, we conclude that both represent good and non-invasive methods for the evaluation of these elements in polluted areas.

Ecological aspects influencing the helminth community of the wood mouse Apodemus sylvaticus in Dunas de Mira, Portugal

This paper presents the first extensive data on the helminth community of the wood mouse Apodemus sylvaticus in a coastal sand dune area in Portugal. The 557 hosts analysed in this study were trapped seasonally between autumn 2002 and summer 2005 across 6 habitat types. Twelve helminth species were detected among which, Taenia parva larvae, Angiostrongylus dujardini, Heligmosomoides polygyrus, Syphacia stroma and S. frederici constitute the component species, accounting for 98.7% of all worms. H. polygyrus was the most prevalent helminth parasite. Species richness varied according to habitat and season. The highest species richness was found in sand dunes during winter whereas the lowest was detected along lake margins also during the winter. Some differences in prevalence and mean intensity values were found in relation to year (T. parva larvae and H. polygyrus), habitat (A. dujardini), season (T. parva larvae, H. polygyrus, A. dujardini and S. stroma) and host sex (T. parva larvae and S. stroma). These differences are discussed both in view of the host’s biology and habitat characteristics.

An assessment of contaminant concentrations in toothed whale species of the NW Iberian Peninsula: Part II. Trace element concentrations

Concentrations of Ag, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, V and Zn were investigated in the liver and kidney of the five most common toothed whales off the Northwest Iberian Peninsula (NWIP), specifically common dolphin, long-finned pilot whale, harbour porpoise, striped dolphin and bottlenose dolphin. Differences were observed in the bioaccumulation of the above elements between the five species. The differences are probably related to biological factors such as age and sex and/or to ecological factors specific to each species such as feeding habits or bioavailability of the various elements. However, no significant relationship was observed between element accumulation and sex. Pilot whale and striped dolphin showed the highest concentrations of renal Cd and the highest concentrations of hepatic Hg and Se, while bottlenose dolphin showed the highest concentrations of Hg in kidneys. An analysis of inter-elemental relationships showed strong positive correlations between Hg and Se in the five species, however most individuals have Hg:Se molar ratio less than 1:1 indicating an excess of Se compare to Hg. This result, probably reflect the high proportion of young animals in the sample available for this study and/or that these animals had a good health status. We also observed a positive correlation in striped dolphins between Cd and Cu and between Cd and Zn in kidneys. In addition, comparing with other studies world-wide, the element concentrations (Hg and Cd) found in Iberian toothed whales indicate that these populations are not specially threatened by Hg and Cd exposure in the area.

SPERMIOGENESIS AND SPERMATOZOON ULTRASTRUCTURE OF THE CESTODE MOSGOVOYIA CTENOIDES (CYCLOPHYLLIDEA: ANOPLOCEPHALIDAE), AN INTESTINAL PARASITE OF ORYCTOLAGUS CUNICULUS (LAGOMORPHA: LEPORIDAE)

Ultrastructural characters in spermiogenesis and spermatozoa are considered important tools to elucidate the phylogenetic relationships within the Platyhelminthes. In the Anoplocephalidae, ultrastructural data refer to the spermatozoon of 14 species, whereas data on spermiogenesis refer to only 7 species. The present study focused on the spermiogenesis and spermatozoon of the anoplocephalid cestode Mosgovoyia ctenoides, as revealed by transmission electron microscopy. Type IV spermiogenesis was detected, beginning with the formation of a differentiation zone containing 2 centrioles, with a centriolar adjunct and vestigial striated rootlets. Different forms of the latter character have been described in other anoplocephalids. This study supports spermiogenesis of type IV as the most frequent in the Anoplocephalidae and confirms the presence of a centriolar adjunct in yet another type IV spermiogenesis species. The spermatozoon of M. ctenoides possesses 1 axoneme of the 9+‘1’ trepaxonematan type, 2 crestlike bodies, dense plates, and granules of electron-dense cytoplasmic material, nucleus, and twisted cortical microtubules. It was again confirmed that the presence of granular material and the absence of both a periaxonemal sheath and intracytoplasmic walls are constant characters in the spermatozoa of all the Anoplocephalinae.

Toxic Element Concentration in the Atlantic Gannet Morus bassanus (Pelecaniformes, Sulidae) in Portugal

The present study provides the first data on inorganic element levels in juvenile, subadult, and adult Atlantic gannets (Morus bassanus). Physiological and potentially toxic elements (As, Cd, Co, Cr, Cu, Hg, Mn, Pb, Se, and Zn) were assessed by ICP-MS in kidney, liver, muscle, and feathers of 31 gannets, including 18 juveniles, 7 subadults, and 6 adults. The effect of age and tissue on element accumulation was also assessed. Mercury was roughly above the minimum level for adverse effects in birds. A higher accumulation of Se and Cd was detected in kidney, Pb in feathers, and Mn in liver. Age was found to affect the accumulation of Cd, Co, Hg, Mn, Se, and Zn. Adults presented significantly lower levels of Mn, Se, and Zn than subadults. Linear positive relationships within tissues were detected involving Se-Cd and Se-Hg. Also, positive linear relationships were detected among kidney, liver, and muscle, with emphasis on relationships involving Cd, Hg, Se, and Zn, which may be indicative of analogous regulation mechanisms in those organs. Atlantic gannets occurring in the study area leave their reproduction sites as juveniles. During their development process, several molting cycles occur and thus the possible contamination risk by Hg should reflect levels in the development areas rather than contamination levels in reproduction areas. The present study provides basic information on multielement accumulation in Morus bassanus, which may help us to understand the behavior and toxicity of various elements in marine birds.

Ingestion of marine litter by loggerhead sea turtles, Caretta caretta, in Portuguese continental waters

The accumulation of litter in marine and coastal environments is a major threat to marine life. Data on marine litter in the gastrointestinal tract of stranded loggerhead turtles, Caretta caretta, found along the Portuguese continental coast was presented. Out of the 95 analysed loggerheads, litter was present in 56 individuals (59.0%) and most had less than 10 litter items (76.8%) and less than 5 g (dm) (96.8%). Plastic was the main litter category (frequency of occurrence=56.8%), while sheet (45.3%) was the most relevant plastic sub-category. There was no influence of loggerhead stranding season, cause of stranding or size on the amount of litter ingested (mean number and dry mass of litter items per turtle). The high ingested litter occurrence frequency in this study supports the use of the loggerhead turtle as a suitable tool to monitor marine litter trends, as required by the European Marine Strategy Framework Directive.

Use of skin and blubber tissues of small cetaceans to assess the trace element content of internal organs

In order to evaluate the use of biopsy samples as non-destructive tool for assessing trace element concentrations in small cetaceans, the concentrations of 14 trace elements were determined in skin, blubber, liver and kidneys of four species of small cetaceans (i.e. common dolphin Delphinus delphis, harbour porpoise Phocoena phocoena, bottlenose dolphin Tursiops truncatus and striped dolphin Stenella coeruleolba), stranded and/or by-caught along the NE Atlantic Ocean coast between 2001 and 2008. Only Cu, Fe, Hg, Mn, Ni and Zn were above the detection limit of the instruments and showed recoveries satisfactory enough to be interpreted. Among these trace elements, Hg was the only one showing a significant correlation between concentrations in and those in liver and kidneys. In consequence skin and blubber can only be used as non-invasive monitoring tissues to investigate Hg bioaccumulation in internal tissues for cetacean populations.

Ecological variables influencing trace element concentrations in bottlenose dolphins (Tursiops truncatus, Montagu 1821) stranded in continental Portugal.

Both the conservation status of bottlenose dolphins (Tursiops truncatus) (Habitats Directive 92/43/CEE, Annex II) and the Marine Strategy Framework Directive demand for data on their ecology and anthropogenic threats. To evaluate the bottlenose dolphins toxicological status in continental Portugal, several trace elements (As, Cd, Cu, Hg, Mn, Ni, Pb, Se, Zn) were determined in 25 stranded individuals. The potential effect of sex, body length and stranding location on trace element concentrations was analysed. In the present study, bottlenose dolphins presented high mercury levels, only exceeded by animals from the Mediterranean and Adriatic seas. Only essential elements were influenced by dolphin sex, whereas Cd, Hg and Pb bioaccumulated in larger dolphins, and hepatic Hg and Cd concentrations were higher in the northwest coast of continental Portugal. The location effect may relate to variations in bottlenose diet and trace element availability, according to the proximity to anthropogenic sources in the Atlantic Iberian coast.