Wild whale faecal samples as a proxy of anthropogenic impact

Abstract

The occurrence of protozoan parasite, bacterial communities, organic pollutants and heavy metals was investigated in free-ranging species of fin (Balaenoptera physalus, n. 2) and sperm (Physeter macrocephalus, n. 2) whales from the Pelagos Sanctuary, Corsican-Ligurian Provencal Basin (Northern-Western Mediterranean Sea). Out of four faecal samples investigated, two from fin whales and one from sperm whale were found positive to Blastocystis sp. A higher number of sequences related to Synergistetes and Spirochaetae were found in sperm whales if compared with fin whales. Moreover, As, Co and Hg were found exclusively in sperm whale faecal samples, while Pb was found only in fin whale faecal samples. The concentration of both PAH and PCB was always below the limit of detection. This is the first report in which the presence of these opportunistic pathogens, bacteria and chemical pollutants have been investigated in faecal samples of free-ranging whale species and the first record of Blastocystis in fin and sperm whales. Thus, this study may provide baseline data on new anthropozoonotic parasite, bacterial records and heavy metals in free-ranging fin and sperm whales, probably as a result of an increasing anthropogenic activity. This survey calls for more integrated research to perform regular monitoring programs supported by national and/or international authorities responsible for preservation of these still vulnerable and threatened whale species in the Mediterranean Sea.

A Comparative Study of Mini-FLOTAC With Traditional Coprological Techniques in the Analysis of Cetacean Fecal Samples

“…Different qualitative copromicroscopic methods have been used in literature for the examination of cetacean fecal samples, with the occasional use of quantitative techniques for the estimation of parasitic burden in free-ranging large whales ( 23 ). Nevertheless, a comparison of the performances of copromicroscopic techniques applied to cetacean stool samples has never been conducted, though the ability of Mini-FLOTAC to detect protozoan cysts has already been reported in stool samples of live, free-ranging large whales ( 6 ). In this study, the direct isolation of helminths from the digestive system after the necroscopic examination was used as a standard reference for the comparison of the results of two tests to be used in vivo in future sampling.…”

“…Free-ranging cetaceans, including large whales and dolphins, are considered sentinels for the marine ecosystem's health. Their long-life span, migratory habits, and role on the top of the trophic chain, as well as their potentiality to be carriers of anthroponotic pathogens, make them useful indicators of chemical pollution, ecological variations, and pressure of human activities on the marine environment (1)(2)(3)(4)(5)(6). The increasing interest in the study of these species has brought the development of new methodologies for sampling live, free-ranging large whales, to obtain a reliable picture of the health of the wild population (4,7).…”

“…Copromicroscopic examination of cetacean feces, following fecal samples collection in vivo, are reported in the literature, using different quali-quantitative techniques, and several different taxa, including helminths and protozoa, have been successfully detected by these methods (4,6,7,23,24). Nevertheless, their reliability has never been verified through comparison with a reference test.…”

Dolphins and sea turtles may host zoonotic parasites and pathogenic bacteria as indicators of anthropic pressure in the Gulf of Taranto (Northern Ionian Sea, Central-Eastern Mediterranean Sea)

“…1 and Table 1). Dolphin fecal samples were collected in the framework of an ecology research project cetaceans; during the winter and summer boat survey, photo identification and floating feces of the individuals were collected, when possible, from free ranging striped (n. 11) and Risso's (n. 7) dolphins using a fine nylon mesh net, which was changed between each sample, avoiding direct contact with animals as also described in Marangi et al 2021. Sea turtle fecal samples were collected from 20 loggerhead and 3 green sea turtles found stranded along the Ionian Sea coast, but still alive or caught by fisherman, in three different sampling zones (1, 2 and 3) within the Gulf of Taranto and kept at two Sea Turtle Rescue Centres (Calimera and Policoro), according to the methodology reported in Marangi et al 2020. Sample ID, collected species, time of sample collecting, cause of finding and sampling zone are reported in Table 1.…”

Pollution Biomarkers in the Framework of Marine Biodiversity Conservation: State of Art and Perspectives

“…In the case of the only pelagic MPA in the Mediterranean Sea, the Pelagos Sanctuary (International Sanctuary for the Protection of Mediterranean Marine Mammals, Corsican-Ligurian Provencal Basin, Northern-Western Mediterranean Sea), biomarkers have been successfully applied to marine mammals, utilizing a nondestructive approach on animal biopsies and fecal material analysis [55][56][57]. In addition, Fossi et al [54] explored the possibility to measure biomarker responses in zooplanktonic euphausiids for the assessment of the environmental quality of the Pelagos Sanctuary.…”