Daily Settlement Rates of the Zebra Mussel, Dreissena polymorpha, on an Artificial Substrate Correlate with Veliger Abundance

1994 ◽  
Vol 51 (4) ◽  
pp. 856-861 ◽  
Author(s):  
André Martel ◽  
Andrea F. Mathieu ◽  
C. Scott Findlay ◽  
Stephen J. Nepszy ◽  
Joseph H. Leach
Keyword(s):  
Water Column ◽  
Late Stage ◽  
Zebra Mussel ◽  
Dreissena Polymorpha ◽  
Cost Effective ◽  
Effective Control ◽  
Physical Factors ◽  
Factors Affecting ◽  
Daily Monitoring ◽  
The Relationship

The relationship between daily settlement rates and local concentrations of veligers of the zebra mussel, Dreissena polymorpha, was investigated using plankton sampling and scouring pad collectors. A total of 102 plankton and 136 collector samples were taken from a nearshore site near Wheatley, Ontario, in west-central Lake Erie, over 17 consecutive d in August 1992. Results demonstrate a strong correlation between daily settlement rates and daily concentrations of late-stage (competent) veligers in the water column (determined at shell lengths ≥ 170 μm; r = 0.93–0.98; p < 0.001; log10-transformed data). Variations in settlement rates of 1–3 orders of magnitude occurred within 24–96 h. Results also suggest that wind-induced hydrodynamics can affect settlement rates of zebra mussel larvae; the period used to monitor settlement (24 h) was much shorter than that employed (~1–2+ wk) in previous studies. Daily monitoring of concentrations of late-stage veligers in the water column as well as settlers (fibrous collectors) may help to identify biological and physical factors affecting short-term variability in settlement; it may also prove advantageous for industries where early detection of colonization by the zebra mussel is critical for cost-effective control of this invasive mollusc.

CRITICAL REVIEW OF EMULSION STABILITY AND CHARACTERIZATION TECHNIQUES IN OIL PROCESSING

2021 ◽  
pp. 1-36
Author(s):  
Vahideh Angardi ◽  
Ali Ettehadi ◽  
Özgün Yücel
Keyword(s):  
Separation Efficiency ◽  
Petroleum Industry ◽  
Cost Effective ◽  
Downstream Processing ◽  
Physical Factors ◽  
Comprehensive Review ◽  
Factors Affecting ◽  
Mathematical Explanations ◽  
The Stability ◽  
The Right

Abstract Effective separation of water and oil dispersions is considered a critical step in the determination of technical and economic success in the petroleum industry over the years. Moreover, a deeper understanding of the emulsification process and different affected parameters is essential for cost-effective oil production, transportation, and downstream processing. Numerous studies conducted on the concept of dispersion characterization indicate the importance of this concept, which deserves attention by the scientific community. Therefore, a comprehensive review study with critical analysis on significant concepts will help readers follow them easily. This study is a comprehensive review of the concept of dispersion characterization and conducted studies recently published. The main purposes of this review are to 1) Highlight flaws, 2) Outline gaps and weaknesses, 3) Address conflicts, 4) Prevent duplication of effort, 5) List factors affecting dispersion. It was found that the separation efficiency and stability of dispersions are affected by different chemical and physical factors. Factors affecting the stability of the emulsions have been studied in detail and will help to look for the right action to ensure stable emulsions. In addition, methods of ensuring stability, especially coalescence are highlighted, and coalescence mathematical explanations of phenomena are presented.

Toxicity of a Traditional Molluscicide to Asian Clam Veligers

2013 ◽  
Vol 5 (1) ◽  
pp. 141-145 ◽  
Author(s):  
Megan Layhee ◽  
Miho Yoshioka ◽  
Bahram Farokhkish ◽  
Jackson A. Gross ◽  
Adam J. Sepulveda
Keyword(s):  
Zebra Mussel ◽  
Dreissena Polymorpha ◽  
Life Stage ◽  
Exposure Period ◽  
Aquatic Invasive Species ◽  
Effective Control ◽  
Water Type ◽  
Asian Clam ◽  
Clam Corbicula ◽  
Aquaculture Facilities

Abstract Aquaculture and hatchery industries are in need of effective control methods to reduce the risk of spreading aquatic invasive species, such as the Asian clam Corbicula fluminea, through aquaculture and hatchery activities. The planktonic nature of Asian clam veligers enables this life stage to enter water-based infrastructure undetected, including hatchery trucks used to stock fish. Once in hatchery trucks, veligers can disperse overland and establish in previously uninvaded habitats. As a result, there is a need to develop techniques that result in veliger mortality but do not harm fish. In September 2012, we conducted laboratory trials to determine if a molluscicide (750 mg/L potassium chloride and 25 mg/L formalin) commonly used to kill zebra mussel (Dreissena polymorpha) veligers in hatchery trucks can also effectively kill Asian clam veligers. We exposed Asian clam veligers to this molluscicide for 1, 3, and 5 h in each of two water types: deionized water and filtered lake water. We found &lt;20% mortality at the 1-h exposure period and 100% mortality at both the 3-h and 5-h exposure periods, regardless of water type. This laboratory study represents an important step toward reducing the spread of Asian clams by aquaculture facilities.

A method for reconstruction of zebra mussel (Dreissena polymorpha) length from shell fragments

1992 ◽  
Vol 70 (12) ◽  
pp. 2486-2490 ◽  
Author(s):  
Diana J. Hamilton
Keyword(s):  
Zebra Mussel ◽  
Dreissena Polymorpha ◽  
Lake Erie ◽  
Strong Relationship ◽  
Zebra Mussels ◽  
Selective Predation ◽  
Diving Ducks ◽  
Point Pelee ◽  
The Relationship ◽  
Shell Fragments

Zebra mussels (Dreissena polymorpha) are subject to size-selective predation by several species of diving ducks and fish in Europe and North America. Ingested mussels are crushed, but the internal septum in the umbonal region of the mussel usually remains intact. Using mussels collected at Point Pelee, Lake Erie, I showed that there is a strong relationship between the length of the septum and of the mussel (r2 = 0.96). I compared this with a similar relationship developed for European zebra mussels and tested both models on mussels collected from Point Pelee and from Stoney Point, Lake St. Clair. Septal length relative to mussel length was greatest at Stoney Point and least at Point Pelee. The European estimates fell between the two. I concluded that to obtain accurate estimates of mussel length when investigating size-selective predation on zebra mussels, the relationship between mussel and septal lengths should be determined at each study location.

Anadromous Sturgeons: Habitats, Threats, and Management

2007 ◽  
Keyword(s):  
Zebra Mussel ◽  
Dreissena Polymorpha ◽  
Sand Dune ◽  
Life Stage ◽  
Lake Sturgeon ◽  
Physical Factors ◽  
Atlantic Sturgeon ◽  
Gammarus Tigrinus ◽  
Juvenile Sturgeon ◽  
Feeding Potential

<em>Abstract.</em>—The St. Lawrence estuarine transition zone (ETZ) harbors the only known concentrations of age-0 and early juveniles of the St. Lawrence Atlantic sturgeon and lake sturgeon populations. Past dredging and disposal operations conducted in the ETZ to deepen the navigation channel resulted in the creation of an extensive sand dune biotope near the juvenile sturgeon concentration areas. In order to characterize the dune biotope within a diversified set of biotopes in the ETZ, nine areas were selected for study, including two areas to cover the sand dune complex. The study objectives were (1) to identify the benthos assemblages of the ETZ and the main physical factors controlling them, (2) to measure the sampling areas’ biological characteristics and feeding potential for sturgeon, and (3) to compare the dune areas’ feeding potential with selected control areas. In 1999–2001, grab sampling was conducted at 141 stations to determine macrobenthos composition and sediment parameters. Depth, slope, and slope orientation were measured from multibeam sonar echosoundings. Salinity, current velocity, and tidal amplitude were provided by a hydrodynamic model of the ETZ. Benthos assemblages were determined using cluster analysis on taxon biomass. Four major assemblages were identified, all having Tubificidae as the dominant or subdominant taxon: zebra mussel <em>Dreissena polymorpha</em>, <em>Gammarus tigrinus</em>, Tubificidae, and <em>Capitella</em> sp. assemblages. A succession of the major assemblages was observed from the freshwater front to the upper mesohaline waters. Three minor assemblages, the Chironomidae, Physidae, and Cumacea, were concentrated in the upper oligohaline zone. Taxonomic richness was highest in areas with the lowest maximum salinity (0.0–0.5), and diversity was highest in areas with intermediate maximum salinities (0.5–2.0). The largest biomass values were found in areas with maximum salinities less than 0.5, in the zebra mussel assemblage. Controls and dune areas had similar macrobenthos richness and diversity, but dune areas had significantly lower densities and biomasses. Feeding potential for a given sturgeon life stage was measured as the sum of taxa biomasses standardized using the prey proportions in that life stage’s feeding regime. For age-0 Atlantic sturgeon and for all lake sturgeon life stages, all of which feed mostly on gammarids, the feeding potential of control and dune areas were not significantly different. For juvenile and subadult Atlantic sturgeon, which feed mostly on tubificids, the dune areas had a significantly lower feeding potential than the control areas. The lower feeding potential of the sand dune areas created by dredged sediment deposition is considered an important issue for the management of the St. Lawrence Atlantic sturgeon population.

Dispersal and Recruitment of Zebra Mussel (Dreissena polymorpha) in a Nearshore Area in West-central Lake Erie: The Significance of Postmetamorphic Drifting

1993 ◽  
Vol 50 (1) ◽  
pp. 3-12 ◽  
Author(s):  
André Martel
Keyword(s):  
Water Column ◽  
Zebra Mussel ◽  
Dreissena Polymorpha ◽  
Lake Erie ◽  
Water Area ◽  
In Situ Growth ◽  
Growth Experiment ◽  
Quantitative Evidence ◽  
Shallow Water Area

Quantitative evidence that early postmetamorphic stages of zebra mussel (Dreissena polymorpha) can disperse in the water column and colonize substrates has been obtained using off-bottom scouring pad collectors and plankton sampling in a nearshore, shallow-water area (2–7 m) near Wheatley, Lake Erie, during August 1991. Collectors were deployed for 24–72 h, thus minimizing growth of recruits during deployments. Size criteria determined through an in situ growth experiment were used to discriminate between individuals arriving at a collector as (1) settling larvae or (2) postmetamorphic stages. During certain periods, 20–80% of individuals settling on collectors were postmetamorphic stages. Plankton samples taken near collectors also confirmed the presence of postmetamorphic stages in the water column. Most drifting juveniles ranged from about 300 μm shell length to 800 μm (some up to 1–2 mm). Although settlement by postmetamorphic stages occurred during various periods, they drifted and settled on collectors in much higher numbers during periods of strong wave action generated during storms. Colonization of natural and man-made substrates by postmetamorphic stages may be significant in exposed or turbulent areas and may impact on population dynamics. Whether postmetamorphic drifting is adaptive and which mechanisms are involved are unknown.

Impact of zebra mussel (Dreissena polymorpha) on phosphorus cycling and chlorophyll in lakes

1995 ◽  
Vol 52 (12) ◽  
pp. 2553-2573 ◽  
Author(s):  
Eric Mellina ◽  
Joseph B. Rasmussen ◽  
Edward L. Mills
Keyword(s):  
Water Column ◽  
Chlorophyll A ◽  
Zebra Mussel ◽  
Dreissena Polymorpha ◽  
Size Structure ◽  
Algal Cell ◽  
Algal Community ◽  
Community Size ◽  
Western Basin ◽  
Excretion Rates

We determined the effects of zebra mussel (Dreissena polymorpha) on water column phosphorus (P) and chlorophyll a levels and algal community size structure as well as rates of P excretion in laboratory experiments. Zebra mussel at a threshold density of 0.25/L were able to decouple the nutrient–chlorophyll relationship, to induce erratic patterns in P and chlorophyll a trends, and to decrease mean algal cell sizes. Using shell length we explained 75 and 71% of the variability in P excretion rates in trials held at 17 and 22 °C. Using mass balance modeling, we examined the effects of zebra mussel growth and mortality on mean annual steady-state P levels as functions of hydraulic flushing and P loadings for the western basin of Lake Erie, for Lake St. Clair, and for Oneida Lake. Zebra mussel affected water column P levels only when the annual P accumulated into mussel biomass represented >20% of the lake's annual P loading. The mussel populations in all three lakes did not substantially affect water column P levels but decoupling of the nutrient–chlorophyll relationship was observed in lakes Erie and St. Clair. No evidence was found for increased decoupling of this relationship with increasing zebra mussel density in European lakes.

Removal of algae by the zebra mussel (Dreissena polymorpha) population in western Lake Erie: a bioenergetics approach

1995 ◽  
Vol 52 (2) ◽  
pp. 381-390 ◽  
Author(s):  
Charles P. Madenjian
Keyword(s):  
Primary Production ◽  
Water Column ◽  
Zebra Mussel ◽  
Dreissena Polymorpha ◽  
Lake Erie ◽  
Mussel Population ◽  
Western Basin ◽  
Bioenergetics Model ◽  
Western Lake ◽  
Western Lake Erie

A bioenergetics model for growth of a zebra mussel (Dreissena polymorpha) individual was verified with observations on zebra mussel growth in western Lake Erie. The bioenergetics model was then applied to the zebra mussel population in the western basin of Lake Erie to estimate the removal of phytoplankton by mussels. According to the modeling results, the zebra mussel population consumed 5.0 million tonnes of phytoplankton, while 1.4 million tonnes of phytoplankton was deposited in pseudofeces from the mussels. Thus, a total of 6.4 ± 2.4 million tonnes of phytoplankton was removed from the water column by zebra mussel in western Lake Erie during 1990. Primary production was estimated to be 24.8 million tonnes; therefore, zebra mussel removed the equivalent of 26 ± 10% of the primary production for western Lake Erie.

Effects of the exotic zebra mussel (Dreissena polymorpha) on metal cycling in Lake Erie

1997 ◽  
Vol 54 (7) ◽  
pp. 1630-1638 ◽  
Author(s):  
P L Klerks ◽  
P C Fraleigh ◽  
J E Lawniczak
Keyword(s):  
Water Column ◽  
Coming Out ◽  
Zebra Mussel ◽  
Dreissena Polymorpha ◽  
Lake Erie ◽  
Zebra Mussels ◽  
Western Lake ◽  
Metal Levels ◽  
Lake Bottom ◽  
The Impact

This research demonstrated the impact of high densities of the zebra mussel (Dreissena polymorpha) on the cycling of copper, nickel, and zinc in a lake environment. Experiments with mussels on sedimentation traps in western Lake Erie and with mussels in flow-through tanks receiving Lake Erie water showed that zebra mussels remove metals from the water column, incorporate metals in their tissues, and deposit metals on the lake bottom. Removal of metals from the water column was estimated at 10-17% · day-1 of the amounts present. This material was largely deposited on the lake bottom; zebra mussels more than doubled the rate at which metals were being added to the lake bottom. Metal biodeposition rates were extremely high (e.g., 50 mg Zn · m-2 · day-1) in high-turbidity areas with elevated metal levels. Two factors contributed to metal biodeposition by zebra mussels. First, their production of feces and pseudofeces increased the rate at which suspended matter was being added to the sediment (accounting for 92% of the increased metal biodeposition). Second, the material coming out of suspension had higher metal concentrations when zebra mussels were present (constituting 8% of the increased biodeposition).

Decline of Native Unionid Bivalves in Lake St. Clair After Infestation by the Zebra Mussel, Dreissena polymorpha

1994 ◽  
Vol 51 (10) ◽  
pp. 2227-2233 ◽  
Author(s):  
Thomas F. Nalepa
Keyword(s):  
Zebra Mussel ◽  
Dreissena Polymorpha ◽  
Extended Period ◽  
Light Weight ◽  
Short Term ◽  
Slow Increase ◽  
The Mean ◽  
The Relationship

To determine impacts of the zebra mussel, Dreissena polymorpha, on bivalves in Lake St. Clair, densities of Unionidae in 1990 and 1992 (after D. polymorpha invasion) were compared with densities in 1986 (before D. polymorpha). Declines in density occurred mainly at sites in the southeastern portion of the lake where unionids were highly infested with D. polymorpha. Unionid densities at highly infested sites declined from 2.4/m2 in 1986, to 1.8/m2 in 1990, and to 0/m2 in 1992. Unionid species with light-weight shells that brood larvae over an extended period declined more between 1986 and 1990 than heavy-shelled, short-term brooders. Unionid densities at lightly infested sites located mainly in the northwestern portion of the lake did not decline: mean densities were 1.4/m2 in 1986, 1.6/m2 in 1990, and 1.4/m2 in 1992. While the mean number of D. polymorpha per unionid was <1 at these lightly infested sites in 1990, it increased to 35 by 1992. Given this relatively slow increase in D. polymorpha per unionid in this portion of the lake, continued monitoring of populations should provide a better understanding of the relationship between the extent of infestations and unionid mortality.

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