RESEARCH

My research encompasses laboratory and field-based applied studies examining the release of metals from anthropogenic wastes to more fundamental studies examining the biogeochemical behavior of metals in lakes and coastal waters. Since arriving at SCSU, I have been busy developing my laboratory facilities, recruiting students to conduct research and further developing my research examining contaminant metals in sediments in the harbors of Long Island Sound. I have been successful in obtaining CSU research funding to support these activities. I have also been successful in recruiting undergraduate students to conduct research in my laboratory. Links are provided here to view and access copies of my publications, current grants and examine our laboratory facilities and capabilities. Below are the research abstracts for the projects undergraduate students have completed under my supervision at SCSU.

Vincent Breslin
Project Title: Sediment Metal Contamination in the Housatonic River

The Housatonic River estuary is typical of many urbanized watersheds in CT with many possible sources of contamination.  Metal contamination of river sediments resulted from wastewater discharges from the brass manufacturing industries located within the watershed from the 1700’s well into the 20th century.  More recently, industries including Chromium Process (Shelton), Whyco Finishing Technologies (Thomaston), Quality Rolling and Deburring (Thomaston) and NRG Devon Operations Inc. (Milford) have been identified among the 35 major toxic (zinc, nickel, copper and chromium) wastewater dischargers in CT.   Increased monitoring is necessary to allow for a better understanding of the impacts of historic and recent industrial discharges on the sediment quality of the Housatonic River estuary.  Results of this study will allow for an assessment of the extent of sediment metal contamination within the river/estuary.  This knowledge is critical for assessing current and future impacts of contaminated sediments on commercial activities and living marine resources within the watershed.  The goal of this study will be to test the following hypotheses: (1) physical properties of the river and harbor sediments will vary from fine-grain, high organic matter content in the inner reaches of the Housatonic river to coarser, low organic matter content in the upper reaches of the river and outside the estuary in LIS and (2) metal contamination will be highest in fine-grained high organic matter content sediment proximate to point sources of contamination.

Participating Students:

Jebediah Stevens
Email: stevensj5@southernct.edu

Vincent Breslin
Project Title: Sediment Metal Contamination in Milford and Clinton harbors.

Previous research has shown that surface sediment metal contamination is highest in the western portion of Long Island Sound and gradually decreases towards the east.  Results of previous research conducted by CCMS faculty and students shows that the trend is also apparent in harbor sediment for large harbors located along the Connecticut shoreline (Norwalk – New London).  To further investigate trends in surface sediment metal concentrations in coastal harbors two similarly sized, yet demographically different, harbors in Milford and Clinton were selected for comparison of sediment metal concentrations.  It is hypothesized that Milford harbor, the more urbanized and industrialized western harbor, will have higher sediment metal contamination than the more rural harbor in Clinton.  Multiple sources of metals are apparent for both harbors and include storm water runoff, tributary rivers, and industrial effluents.  Both harbors also support recreational and commercial boating and fishing.  High spatial resolution sampling using a ponar grab has been conducted in each harbor and harbor sediment is being analyzed for copper, zinc, iron, lead and loss on ignition. 

Participating Students:

Victoria Church
Email: victoriachurch@gmail.com

Jebediah Stevens
Email: stevensj5@southernct.edu

Vincent Breslin
Project Title: Spatial Trends in Oyster Tissue Metal Contents

Metal concentrations in bottom sediments vary at different geographic locations in Long Island Sound but the highest concentrations generally occur in the western end of the Sound and decline toward the east.  Are there similar east-west trends in oyster tissue metal concentrations; are concentrations higher in the western end of the Sound and lower in the eastern end?  Eastern oysters are excellent targets for measuring heavy metal concentrations since they are sessile, have an affinity for the most important pollutants and have high concentration factors (102 to 105) for metals.  Although oysters are good integrators of sediment and water quality, there is no systematic statewide data set for Long Island Sound concerning heavy metal concentrations in oysters.  This research seeks to determine if the commercially important eastern oyster tissue metal contents differ in proportion to exposure to an east-west gradient in sediment and water column metal concentrations located in four different watersheds along the Connecticut coastline.  Metal (Ag, Cd, Cu, Fe, As, and Zn) concentrations will be measured as body burdens from oysters sampled at four locations along the entire Connecticut coastline.  Results of this work will: (1) create a comprehensive data set of oyster tissue metal concentrations and oyster health along the entire CT shoreline; (2) identify trends (west to east), or localized hot spots, associated with oyster tissue metal contents or oyster health within specific watersheds along the CT shoreline

David Oshana
Email: oshanashellfish@gmail.com

Karen Thomas
Email: thomask8@southernct.edu

Vincent Breslin
Project Title: West River Water Quality Monitoring

The West River, a tidal tributary of Long Island Sound, once a salt marsh, was eradicated as such to create an upland recreational area.  One-way flapper tide gates were installed at the southern end of what would become the West River Memorial Park to drain the park and prevent tidal exchange.  A long straight channel was dredged through the length of the park to create a reflective pool of West Rock, reminiscent of that in front of the Washington Monument.  Dredge spoil was deposited on the marsh to create the recreational area and together with the restricted flow of saline water by the tide gates eradicated the salt marsh in the park.  This resulted in an ecologically disturbed wetland, dominated by common reed (Phagmites australis) forming visual and physical barriers to the water.  Additionally, reduced water flows, increased stormwater flows, accumulating pollutants and fluctuating dissolved oxygen levels in the water column have severely impacted habitat quality.  Efforts are underway to restore the original salt marsh by reopening the tide gates and restoring tidal flushing.  Water quality monitoring prior to restored tidal flow is necessary to establish seasonal changes in baseline water quality and to judge the efficacy of restoration efforts.  SCSU students, in partnership with Save-the-Sound, are conducting a water quality monitoring program to include temperature, salinity and dissolved oxygen concentrations at five stations in the West River Memorial Park.   

Participating Students:

Ellen Bulger
Email: bulgere1@southernct.edu

Robert Nicholson (BS Chemistry, 2002) and I examined the sediment metal contamination in the West River Memorial Park, New Haven, CT. As part of this study, Kristin DeRosia (BS Biology, 2002) examined whether the abundance or diversity of benthic invertebrates was affected by the presence of contaminant metals in the sediment. Tina Titus (BS Chemistry, 2004) and I examined the sediment metal contamination in Bridgeport and New Haven Harbors. A brief PowerPoint summary of our harbor research can be accessed here. Matthew Cacopardo (BS Biology, 2004) and I are conducting research examining the accumulation of metals in oysters in New Haven Harbor. Erica Skirvin (BS Chemistry, 2005) is currently examining the depositional history of metals in New Haven harbor sediments. A brief PowerPoint summary of our oyster and harbor core research can be accessed here.

>> In the News

Sediment Metal Contamination in the West River Memorial Park, New Haven

Robert O. Nicholson - Undergraduate Student,
Southern Connecticut State University

Vincent T. Breslin - Assistant Professor,
Dept. of Science Education and Environmental Studies

Southern Connecticut State University

This research was designed to examine the spatial distribution of sediment metal contamination in the West River Memorial Park, New Haven. Seventeen surface (0-3 cm) sediment samples were collected from within the river using a ponar grab from a canoe. Sediment samples were then examined for composition (sand/silt/clay), total organic matter (loss on ignition) and metals. Copper (Cu), zinc (Zn) and lead (Pb) contents of the sediments were measured by atomic absorption spectrophotometry following extraction using a nitric acid-hydrogen peroxide digest technique. Results show that sediment metal concentrations were variable and ranged from 43-609 mg/kg for Zn, 34-430 mg/kg for Pb and from 36-197 mg/kg for Cu. Higher metal concentrations were associated with finer-grained sediment with high organic matter contents. Metal concentrations in some locations within the Memorial Park are 2 to 8 fold greater than metal concentrations expected from weathering of crustal material within the West River watershed.

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Benthic Invertebrate Distribution in the West River Memorial Park, New Haven

Kristin L. DeRosia - Undergraduate Student,
Southern Connecticut State University

Vincent T. Breslin - Assistant Professor,
Dept. of Science Education and Environmental Studies

Southern Connecticut State University

Kristen in the Lab

The West River Memorial Park is a degraded urban marsh habitat close to downtown New Haven. Research within our laboratory has shown that some sediment within the marsh is contaminated with metals of environmental concern (lead, copper and zinc). The present study was designed to examine whether the abundance or diversity of benthic invertebrates is affected by the presence of contaminant metals in the sediment. Seventeen sediment samples were collected from within the marsh using a ponar grab from a canoe. Sediment samples were preserved in stained buffered formalin and sieved through a 1.0 mm screen to isolate organisms. Organism classification is being conducted using appropriate invertebrate keys. Preliminary sorting has revealed obvious differences in the invertebrate species abundance and diversity among various sites within the marsh. Ongoing research is designed to determine if these differences are due to metal contamination in the sediment or differences in other sediment properties.

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Tissue Metal Contents of Eastern Oysters (Crassostrea virginica) in New Haven Harbor

Matthew Cacopardo - Undergraduate Student, Biology Department

Vincent T. Breslin - Associate Professor,
Science Education and Environmental Studies

Southern Connecticut State University

Matthew in the Lab

Eastern oysters (Crassostrea virginica) are known to concentrate chemicals in their soft tissues and are used for evaluating physiologic effects of pollutants. Oysters are also important to the shellfishing industry in Connecticut and are found in areas throughout New Haven harbor. Previous research in our laboratory showed sediment metal contamination in the inner reaches of the harbor surrounding the mouths of the Quinnipiac, Mill and West Rivers. In contrast, sediment in the leased shellfishing grounds located in the outer harbor are characterized by fine to coarse-grained sand with comparably low metal contents. This study is designed to test the hypothesis that oyster tissue metal contents will vary relative to the metal contents of the surrounding sediment.

Natural and caged oysters (placed 10-3-03) were collected from various locations in New Haven harbor including Lighthouse Point, the mouths of the Mill River and Quinnipiac River and the shellfishing beds near Savin Rock. Collection sites were selected based on previous sediment metal analyses at these locations and they are known to represent a wide range of sediment metal contents. A minimum of ten oysters of similar size from each location were harvested on two occasions and depurated in laboratory aquaria in filtered (0.45 µm) water for 48 hours. The soft tissue was removed from each oyster and the individual oyster tissues were oven dried, acid digested, and the digests are being analyzed for iron, copper, zinc, nickel, lead, cadmium and arsenic using flame and graphite furnace atomic absorption spectrometry.

Metal concentrations in natural and caged oyster tissues measured in this study were similar. Natural oyster populations sampled on 11-3-03 from three inner and outer harbor locations yielded mean tissue metal contents ranging from 172 to 368 mg/kg dry wt. for Fe, 690-860 mg/kg dry wt. for Cu and 0.47-0.91 % dry wt. for Zn. For caged oysters sampled on 11-21-03, mean oyster tissue metal contents ranged from 144 mg/kg to 235 mg/kg dry wt. for Fe, 650 to 820 mg/kg dry wt. for Cu and 0.65 to 1.01% dry wt. for Zn. Tissue metal contents for caged oysters sampled from the Savin Rock and Lighthouse Point locations were similar to tissue metal contents for caged oysters sampled from the inner harbor areas (mouths of Mill and Quinnipiac Rivers) even though they are located in areas of comparatively lower sediment metal concentrations. Measured oyster tissue Cu and Zn contents were similar to results of previous studies for oysters sampled in New Haven harbor and significantly higher than previously measured oyster tissue metal contents for oysters collected from Milford and Stratford harbors.

Tissue metal analysis of a second set of caged oysters sampled on 5-10-04 is currently ongoing.

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High Spatial Resolution Sampling of Metals in the Sediment of Bridgeport Harbor, CT and New Haven Harbor, CT

Tina Titus - Undergraduate Student, Biology Department

Vincent T. Breslin - Associate Professor,
Science Education and Environmental Studies

Southern Connecticut State University

Tina sampling in Bridgeport Harbor.

New Haven and Bridgeport Harbors are two of the largest ports of entry in Connecticut and play pivotal roles in the transportation infrastructure and future economic development of the state. Both harbors have been historically characterized by industrial development and are urbanized throughout their watersheds. Surface (0-6 cm) sediment samples were collected from thirteen stations in Bridgeport harbor and 33 stations in New Haven Harbor during 2001-2003 to define a high-resolution spatial distribution of iron, copper, lead, zinc and nickel contamination. Sediment metal contents in New Haven harbor ranged from 6.32 to 405 mg/kg for Cu, 0.77 to 53.0 mg/kg for Ni, 5.83 to 338 mg/kg for Pb, 7.52 to 876 mg/kg for Zn and 0.740 to 2.37 % for Fe. Sediment metal contents in Bridgeport harbor ranged from 29.1 to 492 mg/kg for Cu, 7.56 to 179 mg/kg for Ni, 22.2 to 337 mg/kg for Pb, 44.6 to 514 mg/kg for Zn and 0.759 to 8.44 % for Fe. For bot00h harbors, highest sediment metal concentrations were measured at the inner harbor stations, proximate to the mouths of the tributary rivers. Sediment metal contents were also highest in the fine-grained, inner harbor sediment and were lowest in the coarse-grained sediment located outside the mouth of the harbor in Long Island Sound. For both harbors, Cu, Zn and Pb contents were highly correlated with both the iron and % loss on ignition of the surface sediment. In all areas in both harbors, mean metal concentrations were higher than their respective crustal abundances. Copper was found to have the highest calculated enrichment factors for New Haven and Bridgeport harbors ranging from 35 for the inner harbor sediment in Bridgeport to 7.6 in sediment for the area surrounding the breakwaters in New Haven harbor.

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Sediment Metal Contamination in the Branford River and Harbor

Dr. Vincent T. Breslin; Associate Professor

Dylan Clough, Doug Cucchiarelli, Peter Dart, Charlie Detelich, Sarah Guancial, Michael Guidone, Donna Lawnsby, Grace Loman, Patrick Loman, Jon Navarro; Science Education and Environmental Studies

Southern Connecticut State University

The main stem of the Branford River extends about 10.5 miles in length from just south of Lake Gaillard in North Branford, CT and ends at the Branford harbor before emptying into Long Island Sound. Sections of the river watershed are characterized by suburban development and several point sources of metal contaminants are evident including marinas, a sewage treatment wastewater outfall and industry. Eighteen surface sediment samples were collected on July 1, 2004 in the Branford River south of Interstate 95 and Branford harbor to define a spatial distribution of sediment metal contamination. Results show that metal contents of the Branford River and harbor sediment ranged from 0.7-4.2% for Fe, 21-148 mg/kg for Cu, 3.7-71.7 mg/kg for Cr, 6.5-128 mg/kg for Pb and 35.7-274 mg/kg for Zn. Although sediment metal concentrations varied greatly, they generally reflected differences in sediment type, with higher metal concentrations associated with high loss on ignition, well sorted, fine-grained sediment. Copper, Zn and to a lesser extent Cr, are correlated with sediment loss on ignition. In particular, Cu shows a strong linear relationship with the percentage of organic matter (LOI) found within the Branford River and harbor sediment. Additionally, sediment Cu and Zn concentrations co-vary in the river and harbor indicating a similar source. Results show that sediment Pb, Cu, and Zn contents are elevated above their respective crustal abundances and are similar or higher than previously reported NOAA (1994) Branford harbor mean sediment metal concentrations.

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