Natural and anthropogenic factors shape metazoan parasite community structure in mummichog (Fundulus heteroclitus) from two estuaries in New Brunswick, Canada

Abstract

the mummichog Fundulus heteroclitus (L.) is abundant in euryhaline environments on the east coast of North America, ranging from the gulf of Mexico to the gulf of st. lawrence. it is a common prey item for several species of fishes and shorebirds, and is therefore a key component in intertidal food webs (Scott and Scott 1988). Mummichog are relatively long-lived, with a life span of up to five years, and are largely sedentary, feeding mainly on benthic invertebrates within a restricted home range. these traits make mummichog of potential interest as environmental indicators (e.g., see Finley et al. 2009). Between 1993 and 1995, populations of mummichog were extensively studied in two New Brunswick (canada) rivers putatively experiencing different levels of anthropogenic stress. the Miramichi river received secondary treatment effluent from a bleached kraft pulp mill (BKM), primary treated wastewater from a groundwood mill, effluent from a former wood-preserving plant, and municipal waste. conversely, the Bouctouche river, located approximately 90 km south of the Miramichi, was considered comparatively less polluted; however, it was still subject to non-point inputs of fertilizer and pesticides, as well as municipal effluents from the towns of Bouctouche and sainte-Marie, New Brunswick (Fig. 1). As part of a multidisciplinary effort to contrast the environmental status of the two rivers, a series of coordinated ecotoxicological studies examined a wide range of endpoints in mummichog from two sites in each river, collecting information on levels of individual contaminants in fish tissues, reproductive parameters, measures of immune function, and genetic effects. Mummichog from the site nearest the BKM had elevated tissue levels of chlorophenolic com- ) from a site on the Miramichi River that received bleached kraft pulpmill and municipal effluent. The present study reports differences in the abundance of individual parasite species, as well as parasite infracommunity and component community composition, in mummichog from both rivers. These differences were evaluated in relation to host (size, condition, immune function, tissue organochlorine contaminant levels) and environmental (faecal coliform counts, salinity, temperature) data derived from the previously published studies. Overall, 18 parasite species were identified, the most common of which were Ascocotyle sp. larv., Ornithodiplostomum sp. larv., Posthodiplostomum sp. larv., and Proteocephalus filicollis (Rudolphi, 1802). There were broad differences in parasite community structure and composition between rivers and within rivers, the most prominent pattern being a pronounced difference between sites in the upper and lower estuary of each river that was likely driven by salinity. Mean infracommunity richness was also positively related to faecal coliforms (considered here as a surrogate measure of eutrophication via municipal sewage), and both were highest at the most polluted site. We noted no other significant relationships. Thus our data suggest that the...

Parasite responses to pollution: what we know and where we go in ‘Environmental Parasitology’

“…This study highlights the importance of good sample design and replication. This point is supported by other studies which showed large-scale hydrological effects on parasite communities to be more pronounced than those of contaminants [ 130 – 132 ]. Indeed, Marcogliese et al ([ 129 ] and references therein) suggested that parasite communities as indicators may not be sensitive enough to detect effects of low to moderate pollution or that effects may be overshadowed by those of natural environmental variation.…”

Parasites as biological tags of marine, freshwater and anadromous fishes in North America from the tropics to the Arctic

“…Also, myxozoan communities in spottail shiners are quite different upstream and downstream of the island of Montreal in the same river (Marcogliese et al 2009; Krause et al 2010). Similarly, based on their parasite communities, estuarine and freshwater samples of mummichogs ( Fundulus heteroclitus ) prove quite different from each other in two New Brunswick rivers (Blanar et al 2011). While the above studies do not concern commercial fishes, these species are important forage fishes and the information is certainly relevant if any fisheries employ a more comprehensive ecosystem approach or need to comprehend the resource base for a particular commercial fish species.…”

Variation in parasite communities and health indices of juvenile Lepomis gibbosus across a gradient of watershed land-use and habitat quality

“…As a result of the high parasite diversity of intermediate trophic fishes -i.e., those that consume invertebrates and are prey for both predatory fishes and piscivorous birds -and the ability to estimate age and thus parasite recruitment time, juvenile fish are excellent models to investigate the potential efficiency of parasites as bioindicators for use in environmental monitoring; however, due to the time and knowledge required to sample and identify all parasites present within a host species, previous authors advocate monitoring only individual parasite taxa using prior knowledge of their biology and distribution within a system (Blanar et al, 2011). Additionally, selection of model species for habitat specific data requires that Table 1 Creek watershed land-use, water quality and benthic scores for three creeks in eastern Ontario, Canada.…”