Demographic and genetic evidence of the long-term recovery of (Daphnia galeata mendotae) (Crustacea: Daphniidae) in Sudbury lakes following additions of base: the role of metal toxicity

Abstract

Twenty-year records of changes in abundance of Daphnia galeata mendotae are presented for Middle and Hannah lakes, two metal-contaminated lakes near Sudbury, Ontario, whose acidity was neutralized by additions of base in the mid-1970s. A comparison of allozyme frequencies and abundances of D. g. mendotae in Middle, Hannah, and numerous reference populations indicates that the taxon has fully recovered at both the population and genetic levels of analysis. However, the timing and pace of recovery of D. g. mendotae differed between the two Sudbury lakes. Two 21-day bioassays were conducted to examine the survival and brood production of D. g. mendotae in five treatments simulating 18 years of changes in Cu, Ni, and Cd concentrations in the lakes. The bioassays indicated that metal concentrations, i.e., habitat quality, regulated the pace of recovery of this important zooplankton taxon in the study lakes. Résumé : Nous présentons les données recueillies en 20 ans sur les changements d'abondance de Daphnia galeata mendotae dans les lacs Middle et Hannah, deux nappes d'eau polluées par des métaux faisant partie du groupe de lacs de Sudbury soumis à un traitement de neutralisation par l'addition de d'une base vers le milieu des années 1970. L'étude comparative de la fréquence des alloenzymes et de l'abondance de D. g. mendotae des lacs Middle et Hannah et dans de nombreuses populations de référence a révélé que cette espèce s'est complètement rétablie et ce, tant au point de vue de l'analyse des populations que de l'analyse génétique. Cependant, l'époque où le rétablissement s'est effectué et la vitesse du processus de rétablissement ne sont pas les mêmes dans les deux lacs. Nous avons réalisé deux épreuves biologiques de 21 jours pour étudier la survie et le rendement de reproduction de D. g. mendotae dans des groupes expérimentaux soumis à cinq traitements reproduisant 18 années de changement des concentrations de Cu, Ni et Cd dans les lacs : ces épreuves ont révélé que les concentrations de métaux ou, en d'autres mots, la qualité de l'habitat, ont déterminé la vitesse du rétablissement de cette importante espèce zooplanctonique dans les lacs étudiés. [Traduit par la Rédaction]

Reduced Metals Concentrations of Water, Sediment and Hyalella Azteca from Lakes in the Vicinity of the Sudbury Metal Smelters, Ontario, Canada

“…Reductions in emissions were followed by substantial improvements in water quality (Keller and Pitblado, 1986;Keller et al, 1992;Woodfine and Havas, 1995), biological recovery (Gunn and Keller, 1990) and by general environmental conditions (Crawford, 1995) in some Sudbury lakes. Recovery of many aquatic organisms such as Daphnia mendotae (Yan et al, 1996b), other crustacean zooplankton (Keller and Yan, 1991) and benthic macroinvertebrates (Griffiths and Keller, 1992) were also reported. However a large number of lakes remain acidic and contaminated by metals (Nriagu et al, 1998).…”

A comparison of egg‐bank and long‐term plankton dynamics of two Daphnia species, D. hyalina and D. galeata: Potentials and limits of reconstruction

“…The existence of long-lived dormant eggs in lake sediment offers aquatic ecologists powerful opportunities to reconstruct past population abundances (Yan et al 1996), population genetics (Weider et al 1997), food web structure (Jeppesen et al 2001a,b), and microevolutionary changes (Hairston et al 1999a;Kerfoot et al 1999). The occurrence and abundance of resting stages were used to investigate past population abundance, species invasions, and the species recovery after the restoration of lakes (Verschuren and Marnell 1997).…”

Calcium and sodium as regulators of the recovery of four Daphnia species along a gradient of metal and base cations in metal contaminated lakes in Sudbury, Ontario, Canada

“…Yan et al (1996b) reported D. pulex and D. mendotae in the study lakes, and the Ontario Ministry of the Environment and Climate Change zooplankton data sets from 1970 -2014 also indicate the occasional presence of D. ambigua and D. pulicaria, therefore, colonizers are available. Cladocerans may have been introduced by waterfowl from great distances (Frisch and Green, 2007), or by people from many other undamaged lakes with rich zooplankton assemblages in the region.…”

“…The reduction of the atmospheric emissions diminished the deposition of acid and metals to local watersheds and lakes, and the water quality N o n -c o m m e r c i a l u s e o n l y of many previously impacted lakes improved with time (Keller and Pitblado, 1984;Keller et al, 1999;Jeffries et al, 2003;Keller, 2009;Valois et al, 2011;Webster et al, 2013). Recovery of some lakes was also accelerated by addition of calcareous materials (i.e., liming) to these lakes and their watersheds, including Middle and Hannah (Yan et al, 1996b). For example, in 1973, Hannah Lake, which is located only 4.3 km from the main smelter complex, had among the highest metal levels of local urban lakes, averaging 1108 μg L -1 of Cu and 1865 μg L -1 of Ni at a pH of 4.29 (Yan et al, 1996a).…”