Abundance of (Dreissena polymorpha and Dreissena bugensis) in a warmwater plume: effects of depth and temperature

Abstract

Abstract:The generalization that quagga mussel (Dreissena bugensis) and zebra mussel (Dreissena polymorpha) occur in deep-cold water and shallow-warm water, respectively, is inappropriate. We estimated dreissenid densities at sites affected by warmwater discharges into Lake Erie (Nanticoke, Ontario) to separate the effects of depth and temperature. Both species' densities increased with depth. After controlling for depth, quagga mussel were more abundant at thermally enriched sites than at sites unaffected by the discharge. This suggests that quagga mussel may occur in deep water not because such sites are cooler in summer, but because they are warmer over winter because of the inverse stratification in the range 0-4°C. Zebra mussels were unaffected by the warmwater plume at a broad scale, but were almost entirely absent from a site at the mouth of the discharge canal. This is inconsistent with previous indications that zebra mussel can tolerate higher temperatures than quagga mussel. Even in shallow water unaffected by the discharge, quagga mussel were more abundant than zebra mussel. Because Nanticoke was among the first places in North America to be colonized by quagga mussel, their numerical dominance at Nanticoke may be followed by similar changes in other nearshore areas of the lower Great Lakes.Résumé : La généralisation selon laquelle la moule quagga (Dreissena bugensis) et la moule zébrée (Dreissena polymorpha) se retrouvent dans des eaux froides et profondes et dans des eaux chaudes et peu profondes, respectivement, ne tient pas. Afin de distinguer les effets de la température de ceux de la profondeur, nous avons estimé la densité des dreissénidés dans des stations du lac Érié soumises à des rejets d'eaux chaudes, à Nanticoke (Ontario). Pour les deux espèces, la densité augmentait avec la profondeur. Une fois éliminé l'effet de la profondeur, la moule quagga était plus abondante dans les stations enrichies par la chaleur que dans celles non soumises au rejets. Il est donc possible que ce mollusque se retrouve dans les eaux profondes non pas parce que celles-ci sont plus froides en été, mais parce qu'elles sont plus chaudes en hiver à cause de la stratification inverse des eaux de 0 à 4ºC. Le panache d'eaux chaudes n'avait aucun effet à grande échelle sur la moule zébrée, mais cette espèce était presque complètement absente d'une station située à l'embouchure de l'émissaire. Ces constatations contredisent les indications antérieures selon lesquelles la moule zébrée pourrait tolérer des températures plus élevées que la moule quagga. Même dans les eaux peu profondes non touchées par les rejets, la moule quagga était plus abondante que la moule zébrée. Comme Nanticoke est une des premières localités nord-américaines à être envahie par la moule quagga, la dominance numérique de cette espèce à Nanticoke risque d'être suivie d'une évolution semblable dans d'autres zones côtières des Grands Lacs inférieurs. [Traduit par la Rédaction]

Assessment of Zebra Mussel (Dreissena Polymorpha) Infestation Risk Using GIS for Water Basins in the North-West Bulgaria

“…In summer, the level decreases and these parts usually become dry. Similar pattern of distribution with depth, which reflected the zebra mussel tolerance to natural disturbance and periodic aerial exposure was reported by other authors as well (Mitchell et al, 1996, Jones & Ricciardi, 2005. This may be one of the reasons that evidences of zebra mussel occurrence were found only in reservoirs with bigger depths.…”

Species and epilimnion/hypolimnion‐related differences in size at larval settlement and metamorphosis in Dreissena (Bivalvia)

“…Larvae may immigrate from nearshore shallow water populations or from autorecruitment from deep water populations. The higher density (Mitchell et al 1996) and fecundity (Claxton and Mackie 1998) of nearshore populations favor immigration as the likely source. This question, along with others raised in this study, will remain unresolved until further field studies on the reproduction and larval ecology of deep water populations of quagga mussels are conducted.…”

“…Unlike zebra mussels, which are typically found on hard substrates in nearshore habitats, the quagga mussel can colonize soft-bottom substrates found within offshore deep water habitats of large lakes (Dermott and Munawar 1993;Mills et al 1993Mills et al , 1996Claxton and Mackie 1998). Dermott and Munawar (1993) reported that in Eastern Lake Erie quagga mussels outnumbered zebra mussels by 14 to 1 in the hypolimnion (ϳϾ20 m) and had successfully colonized soft substrates beyond 40 m. In Lake Ontario, Mills et al (1993) collected quagga mussels at a depth of 130 m, and larvae and adults of the quagga mussel also occur in shallow water substrates in Eastern Lake Erie (Mitchell et al 1996).…”

A comparative study of byssogenesis on zebra and quagga mussels: the effects of water temperature, salinity and light–dark cycle

“…Observations in the Great Lakes showed that D. rostriformis bugensis reached high densities and displaced D. polymorpha in the deeper and colder parts of the lakes (Mitchell et al 1996;Nalepa et al 2009). Several experiments showed that the rate of byssogenesis of D. polymorpha increased with temperature (5-308C) (Clarke and McMahon 1996a) or was optimal between 10-208C (Rajagopal et al 1996).…”