Can industrial pollution cause intersexuality in the amphipod, Echinogammarus marinus?

An investigation into intersex amphipods and a possible association with aquaculture

“…Significantly higher frequencies of infection were observed in intersex specimens than in normal specimens. Infection of normal females correlated with the incidence of intersexuality and, as with previous studies (Ford et al, 2006), very few normal males were infected. This suggests that the parasite is a feminiser and is the probable cause of the observed intersexuality.…”

“…Recently we reported higher incidences of intersexuality in the marine/estuarine amphipod Echinogammarus marinus from industrially contaminated sites ( 14-15% intersex) in the Firth of Forth, Scotland, when compared with reference sites ( 5-8% intersex; Ford et al, 2004a). However, results from an additional study have indicated feminising microsporidian parasites as the most probable cause of the observed intersex (Ford et al, 2006). It was hypothesised that conditions at the impacted sites might have enhanced either parasite numbers, or possibly the ability of the parasites to infect immuno-suppressed hosts, thereby causing an indirect form of endocrine disruption.…”

“…Despite evidence that parasitism is likely to be the main cause of the intersex observed in E. marinus at their polluted site, Ford et al (2006) suggested that chemicals may also have indirectly contributed to the observations.…”

Microsporidia parasites disrupt the responses to cadmium exposure in a gammarid

“…Indeed, Keeling and Fast (2002) demonstrated that various physical or chemical stimuli (pH alterations, ultraviolet or peroxide exposure) could induce microsporidia spore germination which could in turn be considered by gammarid as a supplementary stress. Ford et al (2006) observed that gammarid intersex specimens were significantly more likely to be infected with microsporidian parasites at sites receiving waste effluent rather than at reference sites; suggesting that parasitism is related to water quality. Moreover, Jacobson et al (2011) demonstrated that there was an increase in the percentage of parasites infecting the amphipod M. affinis exposed to the antifouling agent tributyltin.…”

Intersexuality in crustaceans: Genetic, individual and population level effects

“…Ford et al (2004a) observed higher proportions of intersex E. marinus at sites associated with pollution when compared to reference sites. These intersexes have subsequently been reported to be caused by feminising microsporidian parasites possibly enhanced through polluted conditions (Ford et al, 2006). Recently, intersex has been demonstrated to be induced chemically in Crustacea by juvenile hormone mimics (Olmstead and LeBlanc, 2007).…”