A new approach to visualize ecosystem health by using parasites

Abstract

A new approach is chosen to visualize ecosystem health by using parasite bioindicators in Segara Anakan Lagoon, a brackish water ecosystem at the southern Java coast, Indonesia. Three fish species (Mugil cephalus, Scatophagus argus, Epinephelus coioides) were collected in two different years and sampling sites and studied for ecto- and endoparasites. Additional data were taken for E. coioides from two further sites in Lampung Bay, Sumatra, and for E. fucoguttatus out of floating cages from a mariculture facility in the Thousand Islands, Jakarta Bay, North Java. The parasite fauna of fishes inside the lagoon was characterized by a high number of ecto- and a low number of endoparasites, the endoparasite diversity was relatively low and the prevalence of ectocommensalistic trichodinid ciliates was high. These parameters were chosen to indicate the biological conditions inside the lagoon. In E. coioides during rainy season, the prevalence of trichodinid ciliates was highest inside the lagoon (55%) compared with 27% in an open-net-cage mariculture and 5.7% in free-living specimens in Lampung Bay. The endoparasite diversity (Shannon-Wiener) was lowest in fish from Segara Anakan lagoon (0.66) compared with fish from an open-net-cage mariculture (0.71) and free-living specimens (1.39). Results for E. fuscoguttatus from the mariculture site in the Thousand Islands, a relatively undisturbed marine environment, demonstrated high parasite diversity (1.58) in the cultivated fish, a high number of endoparasites, and no trichodinids. A star graph is used to visualize the parasite composition for the different fishes, sampling sites, and conditions, using (1) the prevalence of trichodinid ciliates, (2) the ecto/endoparasite ratio and (3) the endoparasite diversity as bioindicators. The application of the star graph is suggested to be a suitable tool to visualize and monitor environmental health under high parasite biodiversity conditions within tropical ecosystems. It can also support a better communication to stake holders and decision makers in order to monitor environmental impact and change.

Parasites of the grouper fishEpinephelus coioides(Serranidae) as potential environmental indicators in Indonesian coastal ecosystems

“…Information on prevalence, intensity, mean intensity and mean abundance of the collected parasite species is summarized in tables 2 and 3. To analyse the parasite composition and ecological status at the respective sampling sites, the ecological parameters as suggested by Palm & Rü ckert (2009) and Palm et al (2011) were considered as given below (table 4). Regional differences for E. coioides were found in terms of endoparasite diversity, total diversity (Shannon-Wiener), Simpson index and Evenness between Bali and in the Segara Anakan lagoon (table 4, figs 2, 3 and 4; for regional comparison see fig.…”

“…The visual integration of the calculated ecological indicators follows Palm & Rü ckert (2009) for the prevalence of trichodinids, ectoparasite/endoparasite ratio and endoparasite diversity after Shannon -Wiener. The Simpson diversity index, Evenness index and hepatosomatic index were added according to Kleinertz et al (2012).…”

“…Ten parasite bioindicators are visualized within a star graph according to Bell & Morse (2003), Palm & Rü ckert (2009) and Palm et al (2011), to illustrate regional differences between the sampling sites. The presented data demonstrate the natural range of these parameters (1) and adjusted parameter range (2) .…”

“…Fish parasites have been used as biological and environmental indicators (for a review see Palm, 2011), especially for environmental change and pollution (Diamant et al, 1999;Dzikowski et al, 2003;Palm & Rü ckert, 2009) or environmental stress (Landsberg et al, 1998). Sures (2001Sures ( , 2003 used acanthocephalan parasites to detect heavy metal pollution, because acanthocephalans accumulate 1000 times higher amounts of heavy metals in contrast to their host tissues.…”

“…We have correlated the observed parasite fauna with regional differences in the sampled regions. Being aware that limited sample replications of theoretically 'impacted' versus 'healthy' environments can be tested in Indonesia, we herewith apply ecological and parasitological parameters that were used to monitor regional differences and environmental change by Palm & Rü ckert (2009) and Palm et al (2011). The use of grouper fish parasites as an early warning system for environmental change in Indonesian coastal ecosystems is discussed.…”