Non-indigenous macroinvertebrate species in Lithuanian fresh waters, Part 2: Macroinvertebrate assemblage deviation from naturalness in lotic systems and the consequent potential impacts on ecological quality assessment

Abstract

The biological pressure represented by non-indigenous macroinvertebrate species (NIMS) should be addressed in the implementation of EU Water Framework Directive as this can have a direct impact on the 'naturalness' of the invaded macroinvertebrate assemblage. The biocontamination concept allows assessment of this deviation from naturalness, by evaluation of abundance and disparity contamination of an assemblage. This study aimed to assess the biocontamination of macroinvertebrate assemblages in Lithuanian rivers, thereby revealing the most high-impact non-indigenous species, and to explore the relationship between biocontamination and conventional metrics of ecological quality. Most of the studied rivers appeared to be impacted by NIMS. The amphipods Pontogammarus robustoides, Chelicorophium curvispinum and snail Litoglyphus naticoides were revealed as high-impact NIMS for Lithuanian lotic systems. Metrics of ecological quality which largely depend upon the richness of indicator taxa, such as the biological monitoring working party (BMWP) score and Ephemeroptera/Plecoptera/Trichoptera (EPT) taxa number, were negatively correlated with biocontamination, implying they could provide unreliable ecological quality estimates when NIMS are present. Routine macroinvertebrate water quality monitoring data are sufficient for generation of the biocontamination assessment and thus can provide supplementary information, with minimal extra expense or effort. We therefore recommend that biocontamination assessment is included alongside established methods for gauging biological and chemical water quality. RÉSUMÉLes espèces de macroinvertébrés non-indigènes dans les eaux douces lituaniennes , Partie 2 : Les écarts à la naturalité des assemblages de macroinvertébrés dans les écosystèmes lotiques et les impacts potentiels conséquents sur l'évaluation de la qualité écologique La pression biologique représentée par des espèces non-indigènes de macroinvertébrés (NIMS) devrait être abordée dans la mise en oeuvre de la directive cadre sur l'eau car cela peut avoir un impact direct sur la « naturalité » des communautés de macroinvertébrés envahies. Le concept de biocontamination permet d'évaluer cet écart de naturalité, par l'évaluation de la contamination en abondance et diversité d'une communauté. Cette étude vise à évaluer la biocontamination des assemblages de macroinvertébrés dans les rivières lituaniennes, révélant ainsi les espèces non indigènes à plus haute incidence, et d'explorer la relation entre la biocontamination et les métriques conventionnelles d'évaluation de la qualité écolo-gique. La plupart des rivières étudiées semblent être touchées par les NIMS. Les amphipodes Pontogammarus robustoides, Chelicorophium curvispinum et les escargots Litoglyphus naticoides se révèlent comme NIMS à fort impact pour les systèmes lotiques lituaniens. Les métriques de qualité écologique, qui dépendent largement de la richesse de taxons indicateurs, tels que le score (BMWP) et le nombre de taxons Ephéméroptères / Plécoptères / Tri...

Continental-wide distribution of crayfish species in Europe: update and maps

“…Substantial distribution expansions of spiny-cheek crayfish and related losses of ICS have been reported from Belarus (Aklehnovich and Razlutskij, 2013), Lithuania (Arbačiauskas et al, 2011a(Arbačiauskas et al, , 2011b and Latvia (Briede, 2011), as well as Germany (Groß et al, 2008;Martin et al, 2008b), Hungary (Györe et al, 2013), and Italy (Aquiloni et al, 2010). We expect further upstream spread of spiny-cheek crayfish in the Vistula Basin (Poland; cf.…”

Macroinvertebrate metrics and their integration for assessing the ecological status and biocontamination of Lithuanian lakes

“…The FAI, a WFD-compliant modification of the biocontamination index (Arbačiauskas et al, , 2011, is a simple, cost-efficient and robust way of assessment of NIMS impact which can be easily implemented within the established routine water quality monitoring programmes.…”

“…The abundance contamination index (ACI; NIMS proportion of individuals) and the disparity contamination index (DCI; NIMS proportion of orders) were calculated for the samples, and the larger value of the ACI or the DCI at a site was then assigned to the biocontamination index (BCI) to attain the metric on a continuous scale (Arbačiauskas et al, 2011). The EQR of the BCI, which we designated as the Fauna Autochthony Index (FAI), was rescaled using the following equation:…”

“…In addition to the biocontamination indices, the abundances of the two high profile invaders, the amphipod P. robustoides (Arbačiauskas et al, 2011) and the zebra mussel Dreissena polymorpha (Pallas, 1771), as well as that of all NIMS, denoted further as #Pr, #Dp and #NIMS respectively, were used as NIMS-specific stressor parameters in the analysis of the relationships between biocontamination and other macroinvertebrate metrics.…”

“…Almost all EU member states support a supplementary evaluation for NIMS impact to uncouple the assessments of NIMS-specific status and anthropogenic pressures (Vandekerkhove and Cardoso, 2010). For a separate assessment reflecting NIMS-specific deviation from naturalness, a biocontamination index which can be derived from the data of routine biological monitoring has been proposed (Arbačiauskas et al, , 2011MacNeil et al, 2010). In this way, the impairments of different origin may be less obscured by each other, and the effectiveness of pressure-specific management measures may be observed clearly (Cardoso and Free, 2008).…”