01972nas a2200265 4500008004100000245015200041210006900193300001000262490000700272520109700279653002501376653002401401653002501425653003001450653001901480653001901499653001401518653001801532100002201550700002201572700001901594700002001613700002101633856005201654 2002 eng d00aField and Laboratory Studies of Ophryoglena sp. (Ciliata: Ophryoglenidae) Infection in Zebra Mussels, Dreissena polymorpha (Bivalvia: Dreissenidae)0 aField and Laboratory Studies of Ophryoglena sp Ciliata Ophryogle a80-850 v793 a

This study, conducted in the Dnieper-Bug Canal in Belarus, is the first to monitor the seasonal (June–November) dynamics of infection with the parasitic ciliate Ophryoglena sp. in a zebra mussel (Dreissena polymorpha) population. Mean population prevalence and intensity of infection varied, respectively, from 11 to 62% and from 0.9 to 24.1 ciliates/mussel. Mean prevalence was highly correlated with mussel length in mussels <20 mm (R2=0.97) and was lower in larger mussels. Mean infection intensity in mussels 1–25 mm long was similarly correlated with their size (R=0.98), reached a maximum in the 20–25 mm size-class, and then sharply decreased, thus providing evidence, albeit limited, that high intensity of infection might be lethal. Transinfection of zebra mussels by Ophryoglena sp. was achieved in the laboratory—a first for a protozoan parasite of D. polymorpha; from an initial complete lack of infection, mean prevalence and intensity rose, respectively, to 86.7% and 8.3 ciliates/mussel.

10aDreissena polymorpha10aInfection intensity10aInfection prevalence10aLaboratory transinfection10aOphryoglena sp10aOphryoglenidae10aParasitic10aZebra mussels1 aKaratayev, A., Y.1 aBurlakova, L., E.1 aMolloy, D., P.1 aVolkova, L., K.1 aVolosyuk, V., V. uhttp://dx.doi.org/10.1016/S0022-2011(02)00021-601965nas a2200205 4500008004100000245014500041210006900186300001200255490000700267520126000274653002601534653002601560653001401586653001501600653001801615100001701633700001901650700002001669856007001689 2002 eng d00aHistological Analysis of Trematodes in Dreissena polymorpha: Their Location, Pathogenicity, and Distinguishing Morphological Characteristics0 aHistological Analysis of Trematodes in Dreissena polymorpha Thei a856-8630 v883 a

Four families of trematodes were observed in histological sections during a 1992–1997 investigation of the parasites of zebra mussels Dreissena polymorpha. These included Aspidogastridae, i.e., Aspidogaster, Echinostomatidae, Bucephalidae, i.e., Bucephalus polymorphus, and Gorgoderidae, i.e., Phyllodistomum folium. This article describes the precise location of these trematodes in the tissues of D. polymorpha, provides graphic evidence of their effect on the organs they inhabit, and highlights the distinguishing morphological characteristics. Evidence of defense reaction of host to trematode infection, i.e., encapsulation of Aspidogaster and nacrezation of B. polymorphus, is also presented and is the first such report for zebra mussels. The histological photomicrographs included represent the first comprehensive series published on trematode infection of zebra mussels. These images, in conjunction with the morphological descriptions presented, should assist researchers in identifying the 4 major trematode taxa that they are likely to encounter in the tissue sections of zebra mussels.

10aDreissena polymorpha.10ahistological sections10aParasites10atrematodes10aZebra mussels1 aLaruelle, F.1 aMolloy, D., P.1 aRoitman, V., A. uhttp://dx.doi.org/10.1645/0022-3395(2002)088[0856:HAOTID]2.0.CO;202687nas a2200253 4500008004100000245010400041210006900145490000700214520193400221653001202155653001902167653001002186653002002196653001502216653001902231653001302250653001802263100002002281700001702301700002802318700002202346700001802368856004702386 2001 eng d00aResponses of Onondaga Lake, NY to early stages of rehabilitation: unanticipated ecosystem feedbacks0 aResponses of Onondaga Lake NY to early stages of rehabilitation 0 v733 a

Responses of polluted Onondaga Lake, New York, to early stages of a phased program to rehabilitate the lake from the effects of domestic waste inputs are documented. The analysis is based on more than 10 years of paired monitoring of the effluent (total ammonia and total phosphorus) of a wastewater treatment plant (WWTP) that discharges to the lake as well as the lake itself (including total ammonia, nitrite, total and dissolved forms of phosphorus, plankton biomass and composition, Secchi disc transparency, and zebra mussel density). Major reductions in total ammonia and total phosphorus loading relative to the preceding decade are reported for the WWTP for the November 1998 through October 1999 interval. Dramatic and, in some cases, unanticipated changes in the lake's water quality and biota in response to the reductions in loading are documented for the April to October interval of 1999 including: (1) major decreases in total ammonia concentrations and improved status with respect to ammonia toxicity standards, (2) development of dense populations of zebra mussels, (3) decreases in fall concentrations of nitrite and improved status with respect to the related toxicity standard, (4) decreases in total phosphorus and total dissolved phosphorus concentrations, and (5) a severe Microcystis (phytoplankton) bloom that caused nuisance conditions and poor clarity. The zebra mussel invasion is attributed to the reductions in total ammonia concentrations to below toxic levels. The Microcystis bloom was probably related to the abrupt increase in the zebra mussel population. Additional reductions in phosphorus loading from the WWTP will be required to limit phytoplankton production and avoid the potential for continued nuisance conditions. Potential complications in resolving lake responses to future reductions in loading associated with the zebra mussel invasion are considered.

10aammonia10aeutrophication10alakes10anuisance blooms10aphosphorus10arehabilitation10atoxicity10aZebra mussels1 aMathews, D., A.1 aEffler, S.W.1 aBrooks), C., W. Mathews1 aSiegfried, C., A.1 aSpada, M., E. uhttp://dx.doi.org/10.2175/106143001X14343909429nas a2200253 4500008004100000245010500041210006900146300001200215490000700227520865200234653002208886653002208908653001508930653003208945653002308977653002509000653001809025100001909043700001909062700001909081700001809100700001709118856004009135 2001 eng d00aCharacterization of Intracytoplasmic Prokaryote Infections in Dreissena sp. (Bivalvia: Dreissenidae)0 aCharacterization of Intracytoplasmic Prokaryote Infections in Dr a203-2160 v443 a

This study characterizes intracytoplasmic infections with prokaryote microorganisms in Dreissena sp. (near Dreissena polymorpha) from northeastern Greece and represents the first report of such infections in freshwater bivalves. Light microscope observations of stained tissues revealed basophilic, cytoplasmic inclusion bodies in 87.5% (28/32) of the mussels sectioned. Inclusions in epithelial cells and connective tissues were noted, respectively, in 34.4 and 71.9% of the sample, with 5 mussels (15.6%) having both tissue types infected. Epithelial cell infections were observed in histological sections only in digestive gland tubules and ducts; within tubules, inclusions were present more often in secretory than digestive cells. Connective tissue infections, however, were systemic; among the 32 mussels sectioned, inclusions were found in the gills (65.6%), foot (12.5%), mantle (9.4%), labial palps (6.3%), digestive gland (6.3%), stomach (6.3%), and gonads (3.1%). Cytoplasmic inclusions (maximum dimension, 138 microm) were prominent enough in the gills to be visible in 17.0% of the 247 mussels dissected. Ultrastructurally, prokaryote cells in gill connective tissues were clearly characteristic of Chlamydiales-like organisms, with each intracytoplasmic inclusion containing a loosely packed mixture of elementary, reticulate, intermediate bodies, and blebs. Prokaryote colonies in digestive gland epithelial cells exclusively contained 1 of 4 morphological cell types and were considered Rickettsiales-like. Hexagonal, virus-like particles were present in the cytoplasm of the largest of these Rickettsiales-like prokaryotes. Although host stress was evident from localized cell necrosis and dense hemocyte infiltration, overall infection was fairly benign, with no major, adverse impact on body condition evident among sectioned or dissected mussels. A possible negative effect was partial constriction of gill water tubes, but at the infection intensity observed (typical range 1 to 7 inclusion bodies per section), significant interference with respiration and other metabolic functions of the gills was highly unlikely.

10aChlamydiales-like10aConnective tissue10aEpithelium10aIntracytoplasmic prokaryote10aRickettsiales-like10aVirus-like particles10aZebra mussels1 aMolloy, D., P.1 aGiamberini, L.1 aMorado, J., F.1 aFokin, S., I.1 aLaruelle, F. uhttp://dx.doi.org/10.3354/dao04420302018nas a2200217 4500008004100000245016600041210006900207300001200276490000700288520126000295653002501555653002601580653001401606653001501620653001801635100001701653700001901670700001801689700002301707856007001730 1999 eng d00aHistological Analysis of Mantle-cavity Ciliates in Dreissena polymorpha: Their Location, Symbiotic Relationship, and Distinguishing Morphological Characteristics0 aHistological Analysis of Mantlecavity Ciliates in Dreissena poly a251-2570 v183 a

Four families of trematodes were observed in histological sections during a 1992–1997 investigation of the parasites of zebra mussels Dreissena polymorpha. These included Aspidogastridae, i.e., Aspidogaster, Echinostomatidae, Bucephalidae, i.e., Bucephalus polymorphus, and Gorgoderidae, i.e., Phyllodistomum folium. This article describes the precise location of these trematodes in the tissues of D. polymorpha, provides graphic evidence of their effect on the organs they inhabit, and highlights the distinguishing morphological characteristics. Evidence of defense reaction of host to trematode infection, i.e., encapsulation of Aspidogaster and nacrezation of B. polymorphus, is also presented and is the first such report for zebra mussels. The histological photomicrographs included represent the first comprehensive series published on trematode infection of zebra mussels. These images, in conjunction with the morphological descriptions presented, should assist researchers in identifying the 4 major trematode taxa that they are likely to encounter in the tissue sections of zebra mussels.

10aDreissena polymorpha10ahistological sections10aParasites10atrematodes10aZebra mussels1 aLaruelle, F.1 aMolloy, D., P.1 aFokin, S., I.1 aOvcharenko, M., A. uhttp://dx.doi.org/10.1645/0022-3395(2002)088[0856:HAOTID]2.0.CO;201678nas a2200205 4500008004100000245007300041210006900114300001200183490000700195520108500202653001701287653001801304653002101322653001801343100001701361700001601378700002201394700001601416856004001432 1998 eng d00aDynamics of Zebra Mussel Oxygen Demand in the Seneca River, New York0 aDynamics of Zebra Mussel Oxygen Demand in the Seneca River New Y a807-8120 v323 a

The magnitude and dynamics of oxygen depletion from zebra mussel metabolism for a severely infested 1.4 km section of the Seneca River, NY, is documented for a 3-month period of 1994, based on hourly measurements of dissolved oxygen (DO) concentrations at an upstream site and a downstream site and mass balance calculations. The average areal zebra mussel oxygen demand (ZOD) in the study section during a 30-day low-flow period (population density ∼40 000 individuals m-2) was 39.4 g m-2 d-1. The average value of ZOD for the same 30-day period, normalized for zebra mussel biomass mass (42.4 mg of O2 (g of zebra mussel)-1 d-1), compares favorably to recently reported oxygen consumption rates from laboratory experiments, sup porting its application elsewhere to accommodate the effects on oxygen resources of invaded systems. Values of ZOD varied greatly during the study reflecting responses of the invader to changes in ambient conditions, including flow and a major decrease in the population.

10amass balance10aoxygen demand10aoxygen depletion10aZebra mussels1 aEffler, S.W.1 aBoone, S.R.1 aSiegfried, C., A.1 aAshby, S.L. uhttp://dx.doi.org/10.1021/es970838v02165nas a2200217 4500008004100000245008800041210006900129300001200198490000700210520153500217653001601752653001401768653001001782653001401792653001401806653001801820653001801838100001701856700002201873856005201895 1998 eng d00aTributary Water Quality Feedback from the Spread of Zebra Mussels: Oswego River, NY0 aTributary Water Quality Feedback from the Spread of Zebra Mussel a453-4630 v243 a

Dramatic changes in the water quality of the Oswego River system, including Oswego Harbor, since the early 1990s brought about by zebra mussel (Dreissena polymorpha) infestation are documented. The analysis is based on summertime (June to September) water quality monitoring of the Oswego Harbor (1981 and 1993), the mouth of the Oswego River (1983 to 1993), and three upstream sites in the Oswego River system (1990, 1991, and 1994), and two benthic surveys conducted along a 70 km reach of the system to the mouth of the Oswego River in 1994. It is estimated that water in the Oswego River was filtered more than twice over this length by the mussels in 1994 (at median flow) before it reached Oswego Harbor. The zebra mussel infestation converted the Oswego River and the harbor from a turbid (low clarity), phytoplankton-rich, nutrient-depleted system, to a system with distinctly greater clarity, reduced phytoplankton concentrations, enriched in soluble reactive phosphorus. Most of this impact was attributable to dense zebra mussel populations (e.g., ∼ 30,000 indiv/m2) in a 5 km river section, located > 60 km upstream of Oswego Harbor. These changes in tributary water quality represent a form of feedback associated with the spread of the zebra mussel from the Laurentain Great Lakes. Increased attached algae growth in the Great Lakes proximate to the inflow of infested tributaries is a reasonable expectation in response to the more available form of the phosphorous load.

10achlorophyll10anutrients10ariver10atributary10aturbidity10awater quality10aZebra mussels1 aEffler, S.W.1 aSiegfried, C., A. uhttp://dx.doi.org/10.1016/S0380-1330(98)70835-404351nas a2200205 4500008004100000245009600041210006900137300001200206490000700218520365100225653002403876653002003900653001403920653001403934653001903948653003703967653001804004100001904022856010404041 1998 eng d00aThe Potential for Using Biological Control Technologies in the Management of Dreissena spp.0 aPotential for Using Biological Control Technologies in the Manag a177-1830 v173 a

Broadly defined, biological control is the use of one species for the suppression of another. Two groups of organisms have potential as Dreissena control agents: selectively toxic microbes and natural enemies. Selectively toxic microbes are naturally occurring soil and water microorganisms that simply by chance happen to be toxic to Dreissena. Applied at artificially high densities to water, the microbial cells per se or their released metabolites are selectively lethal to Dreissena. In contrast, natural enemies are organisms that, by their evolutionary nature, will debilitate or kill Dreissena, including predators, parasites (both multicellular and

microbial), and benthic competitors (organisms capable of competitively displacing Dreissena from substrates).

Selectively Toxic Microbes: In the short run, these microorganisms represent the most promising candidates as biological control agents, The use of highly-specific, toxic microbes has a clear record of commercial success and environmental safety in the control of invertebrate pests in North America. and strains lethal to Dreissena have been already isolated. Considering how quickly a selectively toxic microbe could move from the laboratory to commercialization, continued research to develop this microbial control strategy is a high priority.

Natural Enemies; In North America, as in Eurasia, there will likely be isolated field reports of major impacts by natural enemies, and, on the whole, we will likely see a cumulative effect of a complex of enemies having a constant, but limited, role in naturally suppressing Dreissena populations. In the majority of cases, Dreissena populations will cause economic and ecological effects at densities well below those that their enemies could naturally maintain. This does not mean, however. that certain natural enemies could not be artificially manipulated (e.g., mass produced and released in an inundative fashion) to cause major Dreissena reductions.

1. Parasites: These natural enemies would likely be the most environmentally-safe biocontrol agents, due primarily to their high host specificity. Comprehensive investigations to identify parasites that are strictly specific to Dreissena and that can be economically mass produced are a key research priority. Parasites from Dreissena’s native Eurasian range should be studied to identify species that would be “nearly risk free” candidates for importation into North America. Research to uncover parasites of Dreissena that are already present in North America should be intensified.

2. Predators: Although organisms, such as fish and birds, have sometimes been documented to consume Dreissena at high rates, this does not necessarily mean that they would be effective candidates for use in control programs. Predators are typically not specific enough in their prey choices. A predator introduced to a waterbody from outside its natural range may highly prefer Dreissena as a prey item, but will also consume other aquatic organisms. The consumption of such nontarget prey could potentially have serious, adverse, ecological impacts.

3. Benthic Competitors; In addition to being micro/macrofouling organisms themselves, the lack of specificity of species that can competitively displace Dreissena from substrates (e.g., sponges) significantly reduces their potential as biocontrol agents.

10abenthic competitors10anatural enemies10aParasites10apredators10aquagga mussels10aselectively toxic microorganisms10aZebra mussels1 aMolloy, D., P. uhttps://www.nysm.nysed.gov/staff-publications/potential-using-biological-control-technologies-manag02579nas a2200181 4500008004100000245007900041210006900120300001200189490000700201520198300208653001102191653001902202653001802221100001702239700002102256700001902277856010102296 1996 eng d00aUse of Sieves for the Rapid Size Selection of Dreissena polymorpha Samples0 aUse of Sieves for the Rapid Size Selection of Dreissena polymorp a747-7500 v153 a

We describe a method that uses sieves of uniform pore size for rapidlysize sorting large populations of Dreissella polymorpha (zebra mussels) or collecting large numbers within a selected size range. This method may be a valuable tool applicable to a wide range of zebra mussel research projects and possibly also useful in size sorting other bivalve species. Sieves are used in pairs and are repeatedly moved vertically in and out of a water column, with mussels passing lengthwise down through the pores. The upper and lower limits of the size range of mussels collected between the sieves are determined by the pore sizes of the upper and lower sieves, respectively. Sieve pairs with pore sizes of 6.30 and 5.60 mm, 5.60 and 4.75 mm, and 4.75 and 4.00 mm, for example, yielded mussels in size classes of 13.8-10.3, 12.6-8.5, and 10.6-7.0 mm in length, respectively. Sieving in the field eliminated the need to transport mussel-laden rocks and other substrates to the laboratory, reduced the effort required to properly dispose of musselcontaminated materials, and proved even simpler to perform than in the laboratory. One of the challenges in using this sieving procedure is determining the exact sieve sizes that will retain mussels only within a particular length range. For example, because large numbers of zebra mussels 6-11 mm in length are used in our laboratory's research program, trials were conducted to compare the effectiveness of sieving and hand picking to obtain mussels solely within this size class. With sieves of 5.6 and 2.8 mm pore sizes, the mean yield of mussels was over three times faster by sieving than hand picking (10.2 versus 3.0 mussels/min), but 7.1% of the mussels collected were outside the desired length range of 6-11 mm. In judging the usefulness of this sieving procedure, an error factor such as this is unavoidable and must be weighed in individual research projects against the significant increase in mussel yield.

10aSieves10asize selection10aZebra mussels1 aBiss, J., B.1 aLaruelle, F., H.1 aMolloy, D., P. uhttps://www.nysm.nysed.gov/staff-publications/use-sieves-rapid-size-selection-dreissena-polymorp02131nas a2200229 4500008004100000245005900041210005900100300001200159490000700171520148600178653002601664653002101690653001801711653001801729100001901747700001901766700001801785700002201803700001601825700001901841856004101860 1996 eng d00aImpact of Zebra Mussel Invasion on River Water Quality0 aImpact of Zebra Mussel Invasion on River Water Quality a205-2140 v683 a

The biology of the zebra mussel is reviewed as it relates to water-quality problems in rivers. A relationship between population densities of the zebra mussel and their respiration demands for oxygen is developed, which can be used to support the analysis of the impact of zebra mussel infestation on the oxygen resources of streams and rivers. Dramatic changes in the water quality of the Seneca River, N.Y., a major tributary to Lake Ontario, have been brought about by zebra mussel infestation. These changes are documented from 3 years of monitoring data. The infestation converted the Seneca River from a turbid, phytoplankton-rich, nutrient-depleted system, with nearly saturated oxygen concentrations, to a river with high clarity, low-phytoplankton concentrations, enriched in dissolved nutrients, with greatly undersaturated oxygen concentrations. The degradation of oxygen resources was severe enough to cause violations of New York State standards for daily minimum and daily average concentrations for a number of days in the late summer of 1993. The associated loss in the waste assimilative capacity of the river is confounding waste discharge management and planning efforts in the river basin. This form of degradation is expected for other systems as the zebra mussel infestation spreads. The impact is expected to be greatest in rivers and streams with high concentrations of phytoplankton, large areas of rock substrate, and limited reaeration capacity.

10aassimilative capacity10adissolved oxygen10awater quality10aZebra mussels1 aEffler, S., W.1 aBrooks, C., M.1 aWhitehead, K.1 aSiegfried, C., A.1 aWalrath, L.1 aCanale, R., P. uhttp://www.jstor.org/stable/2504470802162nas a2200193 4500008004100000245018200041210006900223300001200292490000700304520146800311653002301779653001501802653001401817653001801831100001901849700001501868700001601883856006901899 1994 eng d00aShort-term Reduction of Adult Zebra Mussels, Dreissena polymorpha, in the Hudson River Near Catskill, New York: An Effect of Juvenile Blue Crab (Callinectes Sapidus) Predation?0 aShortterm Reduction of Adult Zebra Mussels Dreissena polymorpha  a367-3710 v133 a

During the summer of 1992, a loss of 2- to 3-cm zebra mussels, Dreissena polymorpha, was recorded in the Hudson
River near Catskill, NY. We document this adult population crash and present field and laboratory data suggesting that predation by
blue crabs, Callinectes sapidus, was responsible. Dredge samples on July 8th indicated that the mean density of the largest zebra
mussel size class (length = 2 to 3 cm) in the Hamburg-Catskill-Germantownregion was 664 m-2 (range of 59 to 2,222 m-2, 14rucks
examined). In sharp contrast, extensive dredging on August II th did not recover a single mussel of that size class in that area. The
largest mussel collected on August 11th was only 0.7 em long, with over 100 rocks examined. An abundance of shell fragments and
detached, live mussels were considered evidence of predation, possibly by a large immigrant blue crab population present in the area.
Laboratory trials confirmed that these crabs can aggressively consume zebra mussels, particularly the size class that was virtually
eliminated in the Catskill area, and that their feeding does result in piles of shell fragments and removed, yet unconsumed mussels.
Further supportive evidence of the blue crab predation hypothesis was gained in the summers of 1993 and 1994, when blue crabs did
not migrate into the Catskill area and a massive decline in 2 to 3 cm mussels did not occur.

10aBiological control10ablue crabs10apredation10aZebra mussels1 aMolloy, D., P.1 aPowell, J.1 aAmbrose, P. uhttp://www.academia.edu/download/34389015/Molloy_et_al._1994.pdf00460nas a2200133 4500008004100000245005800041210005800099300000800157490000700165653002300172653001800195100001900213856009400232 1993 eng d00aApproaches to the Biological Control of Zebra Mussels0 aApproaches to the Biological Control of Zebra Mussels a1470 v1210aBiological control10aZebra mussels1 aMolloy, D., P. uhttps://www.nysm.nysed.gov/staff-publications/approaches-biological-control-zebra-mussels