Irondequoit Bay Research Articles

Impact of Microplastic on Freshwater Sediment Biogeochemistry and Microbial Communities Is Polymer Specific

Plastic debris is a growing threat in freshwater ecosystems and transport models predict that many plastics will sink to the benthos. Among the most common plastics found in the Laurentian Great Lakes sediments are polyethylene terephthalate (especially fibers; PET), polyvinylchloride (particles; PVC), and styrene-butadiene rubber resulting from tire wear (“crumb rubber”; SBR). These materials vary substantially in physical and chemical properties, and their impacts on benthic biogeochemistry and microbial community structure and function are largely unknown. We used a microcosm approach to evaluate the impact of these three plastics on benthic-pelagic coupling, sediment properties, and sediment microbial community structure and function using sediments from Irondequoit Bay, a major embayment of Lake Ontario in Rochester, New York, USA. Benthic metabolism and nitrogen and phosphorous cycling were all uniquely impacted by the different polymers. PET fibers and PVC particles demonstrated the most unique effects, with decreased ecosystem metabolism in sediments containing PET and greater nutrient uptake in sediments with PVC. Microbial diversity was reduced in all treatments containing plastic, but SBR had the most substantial impact on microbial community function, increasing the relative importance of metabolic pathways such as hydrocarbon degradation and sulfur metabolism. Our results suggest that individual polymers have unique impacts on the benthos, with divergent implications for ecosystem function. This provides deeper insight into the myriad ways plastic pollution may impact aquatic ecosystems and will help to inform risk assessment and policy interventions by highlighting which materials pose the greatest risk.

Complete sequences of 4 viral hemorrhagic septicemia virus IVb isolates and their virulence in northern pike fry.

Four viral hemorrhagic septicemia virus (VHSV) genotype IVb isolates were sequenced, their genetic variation explored, and comparative virulence assayed with experimental infections of northern pike Esox lucius fry. In addition to the type strain MI03, the complete 11183 bp genome of the first round goby Neogobius melanostomus isolate from the St. Lawrence River, and the 2013 and 2014 isolates from gizzard shad Dorosoma cepedianum die-offs in Irondequoit Bay, Lake Ontario and Dunkirk Harbor, Lake Erie were all deep sequenced on an Illumina platform. Mutations documented in the 11 yr since the MI03 index case from Lake St. Clair muskellunge Esox masquinongy showed 87 polymorphisms among the 4 isolates. Twenty-six mutations were non-synonymous and located at 18 different positions within the matrix protein, glycoprotein, non-virion protein, and RNA polymerase genes. The same 4 isolates were used to infect northern pike fry by a single 1 h bath exposure. Cumulative percent mortality varied from 42.5 to 62.5%. VHSV was detected in 57% (41/72) of the survivors at the end of the 21-d trial, suggesting that the virus was not rapidly cleared. Lesions were observed in many of the moribund and dead northern pike, such as hemorrhaging in the skin and fins, as well as hydrocephalus. Mean viral load measured from the trunk and visceral tissues of MI03-infected pike was significantly higher than the quantities detected in fish infected with the most recent isolates of genotype IVb, but there were no differences in cumulative mortality observed.

Phosphorus cycling in a managed lake ecosystem: Seasonal and longer-term trends

► P cycling in an oxygenated lake. ► Internal P loading during summer thermal stratification. ► Release of P from oxyhydroxide phases during periods of low dissolved oxygen. Irondequoit Bay, adjacent to Rochester, New York, is one of the larger embayments along the southern coast of Lake Ontario. Since the 1980s, management activities have been focused on improving water quality and the trophic status of the bay, including a program of hypolimnetic oxygenation. During the summers of 2003, 2004 and 2009, a program of basic water quality parameter profiles and sediment sampling completed. Results of these surveys show an increase in hypolimnetic P throughout each summer season. The increase in P is concordant with decreasing dissolved O 2 concentrations. Although the dissolved O 2 levels are persistent in the suboxic range for most of the summer season, the oxygenation program prevents anoxic conditions, limiting the release of P to that associated with Mn oxyhydroxides. Longer-term trends show an upward linear trend in metalimnetic P which is associated with the trophic status of the bay. This upward trend may be linked to cycling and enrichment of the near surface sediment in P.

Phytoplankton community assessment in eight Lake Ontario tributaries made using fluorimetric methods

Coastal inputs of nutrients and contaminants impact phytoplankton community composition and health in localized and large areas of coastal Lake Ontario. Advanced fluorimetric instrumentation (Fast Repetition Rate Fluorimeter [FRRF], FluoroProbe) was used during June 2006 to assess the in situ phytoplankton community of eight tributaries of Lake Ontario (Chaumont Bay, Sacketts Harbor/Black River, Oswego River, Port Bay, Sodus Bay, Irondequoit Bay, Genesee River, and Eighteen Mile Creek) representing a range of geomorphological features (rivers, protected embayments, open embayments). The instrumentation enabled high resolution (160 m) continuous monitoring of phytoplankton community composition (FluoroProbe) and photosynthetic efficiency (FRRF) along 1 m deep transect from nearshore (coastal Lake Ontario, > 7 m depth) to inshore (within the tributary, < 7 m depth). Limnological parameters such as water temperature, colored dissolved organic matter content (CDOM), total phosporus, nitrate, chloride, light extinction coefficient, and extracted size fractionated (0.2–2 μ m, 2–20 μ m, > 20 μ m) chlorophyll a concentrations were also determined. Results from this study illustrate the strong environmental gradients that exist along tributary transition zones into Lake Ontario. Offshore water quality was homogeneous and reflected nutrients levels (e.g. total phosphorus) that were below the Great Lakes Water Quality Agreement target value (10 μ g per litre), whereas most tributary inputs had elevated nutrient and chloride levels. Phytoplankton community composition differed between inshore and offshore sites and the transition coincided with changing water quality (followed using water temperature and CDOM concentrations) at the interface of the surface water masses. The greatest observed photosynthetic efficiencies occurred in the inshore environment; this is attributed to the greater nutrient availability rather than lower light levels. Fluorimetric applications provide useful techniques for monitoring water quality. Given the observed diversity of phytoplankton community and health among these tributary inputs, it follows that monitoring capabilities using the instrumentation applied here should be enhanced to observe these systems.

Does Manganese Influence Phosphorus Cycling under Suboxic Lake Water Conditions?

The comparative roles of iron and manganese in internal phosphorus loading were examined in a managed lake. Sediments and the water column of Irondequoit Bay, an embayment along Lake Ontario's southern shore, were sampled monthly during summer thermal stratification. Total phosphorus, total iron, and total manganese concentrations in the sediment averaged 1.389 ± 0.150 g/kg dry wt, 24.415 ± 0.760 g/kg dry wt, and 1.727 ± 0.053 g/kg dry wt, respectively. Elevated total phosphorus (maximum = 0.915 mg P/L) and soluble reactive phosphorus (maximum = 0.749 mg P/L) concentrations were observed in the hypolimnion. Sequential extraction of phosphorus fractions from the top 25 cm of deepwater sediment revealed that approximately 25% of phosphorus was stored in a redox-sensitive form, most likely associated with iron and manganese oxyhydroxides. Typically, phosphorus released from sediments is associated with iron, not manganese. However, iron and manganese profiles from the water column indicated that manganese from the sediment was cycling with phosphorus into the overlying waters, while iron did not demonstrate evidence of cycling. Although reductive dissolution of iron likely occurs in the sediment, iron was retained in the sediment and kept out of the water column by the maintenance of low concentrations of dissolved oxygen in the hypolimnion.

ESTABLISHMENT OF A METALIMNETIC OXYGEN REFUGE FOR ZOOPLANKTON IN A PRODUCTIVE LAKE ONTARIO EMBAYMENT

Hypolimnetic oxygen injection is a management tool used to improve water quality by preventing anoxia and associated phosphorus release from the sediments. An additional benefit would be formation of a low-oxygen refuge for large-bodied herbivorous zooplankton in the metalimnion. The magnitude and timing of hypolimnetic oxygenation was deliberately manipulated during summer 1997 in Irondequoit Bay, a eutrophic Lake Ontario embayment (New York, USA), to maintain metalimnetic dissolved oxygen (DO) concentrations in the range of 1–2 mg/L. We assessed the vertical distributions of fish and zooplankton in 1997, a year with controlled oxygenation, and 1996, a year with oxygenation but without a deliberate attempt to create amenable refuge conditions. After initiation of oxygenation, June through early August metalimnetic DO in 1997 was 1.8 ± 0.5 mg/L (means ± 2 se), whereas metalimnetic DO in 1996 was 3.8 ± 1.0 mg/L. Hydroacoustic surveys in 1997 and gillnet catches in both years indicated that >96% of planktivorous fish, alewives (Alosa pseudoharengus) and emerald shiners (Notropis atherinoides), were restricted to depths with DO > 4.0 mg/L. A refuge effect in 1996 was slight and evidenced only by significantly larger zooplankton in the metalimnion while densities of Daphnia galeata medotae and D. retrocurva were similar or significantly greater in the epilimnion. In 1997, the refuge effect was strong despite an almost twofold increase in planktivorous fish abundance compared to 1996. Overall zooplankton densities were similar in the epilimnion and metalimnion while zooplankton size and densities of both daphnids were significantly greater in the metalimnion. Densities of an invertebrate predator, Mesocyclops edax, were also significantly higher in the metalimnion compared to the epilimnion. Despite high fish abundance in 1997, mean summer (late May through August) chlorophyll a decreased 29% compared to 1996, consistent with expectations from grazing by large Daphnia protected in the refuge. Presence of large-bodied zooplankton in 1997 despite high planktivore abundance demonstrated that successful creation of a low-oxygen refuge from fish predation was possible in an open Great Lakes embayment where traditional biomanipulation via fish removal was not practical.

Submerged Macrophytes in Lake Ontario: Current Knowledge, Importance, Threats to Stability, and Needed Studies

The submerged limnetic community in Lake Ontario includes algae, bryophytes, and about 30 species of angiosperms. Their distribution is accurately known in some areas but not lake-wide, and a whole-lake survey is recommended. In nutrient cycling, submergents act as sinks during the summer; metals and metalloids occur in high concentrations in tissues from some areas. Known herbivores include invertebrates, fish, and waterfowl. Stands are necessary for many fish taxa as breeding or nursery habitats, and for waterfowl, but may be damaged by carp (Cyprinus carpio). Stability has been affected by water levels, sedimentation, wave and ice movement, invasive species, herbivory, eutrophication and turbidity, and contaminants. Recovery after control of P loading has occurred in Irondequoit Bay but is delayed by turbidity in the Bay of Quinte.

Meromixis in Ides Cove, N.Y.: Causes and Recovery

ABSTRACT Ides Cove is a small, relatively deep, isolated body of water adjoining Irondequoit Bay of Lake Ontario, Irondequoit, N.Y. In 1970–1971, the cove was meromictic with meromixis being attributed to the heavy application of delcing salts in the cove's watershed. Application of deicing salts to roads in the Town of Irondequoit has steadily declined from > 31,000 metric tons in 1970–1971 to < 4,000 tons in 1979–1980. The resultant decrease in salt concentrations of the surface waters of the cove since 1970 is evidence of recovery from meromixis. Also, complete mixing of the water column observed during the winter of 1979–1980 suggests that the town's “sensible salt use policy” has been a success. However, Cl− concentrations and conductivity in the hypolimnion during the spring, summer, and autumn have remained high due primarily to the discharge of naturally occurring salt from groundwater streams (mean annual Cl− = 303 mg/1) into the cove. The addition of naturally occurring salt into the cove currently affects mixing patterns by suppressing the autumn and spring turnover and probably affected mixing patterns in a similar manner prior to the advent of deicing operations.

Runoff of Deicing Salt: Effect on Irondequoit Bay, Rochester, New York

Salt used for deicing the streets near Rochester, New York, has increased the chloride concentration in Irondequoit Bay at least fivefold during the past two decades. During the winter of 1969-70 the quantity and salinity of the dense runoff that accumulated on the bottom of the bay was sufficient to prevent complete vertical mixing of the bay during the spring. Comparison with 1939 conditions indicates that the period of summer stratification has been prolonged a month by the density gradient imposed by the salt runoff.

Seasonal Variation of Some Limnological Factors in Irondequoit Bay, New York

During the summer of 1939 a series of samples was taken in the deeper part of Irondequoit Bay as a part of the general Biological Survey of the Lake Ontario Watershed conducted by the New York Conservation Department (Tressler and Austin, 1940). The results of this mid-August sampling indicated a high degree of productivity and extreme stagnation conditions, which prompted the continuation of these studies during the following year. An extensive program of independent investigation was begun in September 1939 and was continued at monthly intervals until June 1940, when all three authors moved permanently from the state and as a consequence the work had to be discontinued. The present paper deals with the seasonal cycle in the bay from August 15, 1939, to June 13, 1940.

Growth, Habits, and Fecundity of the Ciscoes of Irondequoit Bay, New York

This paper presents a study of ciscoes of Irondequoit Bay, New York, and deals with their migration, age and time of spawning, associated species at the time of spawning, predators, and conservation. This study is based on the age determinations of 505 specimens, on the calculations of the length at the end of various years of life of 500 of these ciscoes, and on the examination of the ovaries of 104 fish. The ciscoes of Irondequoit Bay belong to two related forms, but further study will be needed before their taxonomic status may be established satisfactorily. Calculated lengths were usually lower than actual lengths at capture of fish of the same age. The curve of growth in length is typical for the species and is the same for both males and females. However, the females generally run heavier than the males at corresponding lengths. Fecundity was estimated by the volumetric method. It was determined by actual counts that this method involved an error of 5.1 per cent. Fecundity increased with age, fish in age group VIII producing three to four times as many eggs as the group II individuals. Although there appears to be a great deal of variation in the fecundity at a particular age, the tendency is toward an increase with an increase in length and weight.