Ronald Rossmann

Trace Element Concentrations in Near-Surface Waters of the Great Lakes and Methods of Collection, Storage, and Analysis

Abstract From 1980 through 1985, waters of the Great Lakes were sequentially sampled for dissolved, paniculate, and total trace elements. Major sampling occurred in 1980 for Lake Huron, in 1981 for Lakes Erie and Michigan, in 1983 for Lake Superior, and in 1985 for Lake Ontario. Great care was taken during collection, storage, and analysis to prevent sample contamination and to document any contamination occurring. Trace elements measured by atomic absorption techniques were silver, aluminum, arsenic, boron, barium, beryllium, bismuth, cadmium, cobalt, chromium, copper, iron, mercury, lithium, manganese, molybdenum, nickel, lead, antimony, selenium, tin, strontium, vanadium, and zinc. All results were field and laboratory blank corrected. Excluding aluminum, barium, iron, and strontium, concentrations of trace elements in most of the Great Lakes were a few ppb or less, with many elements being below one ppb. Element concentrations were highest in Lakes Erie and Michigan and lowest in Lakes Huron and Superior. All five Great Lakes had more than 50% of their total iron, aluminum, and manganese associated with paniculate matter.

Organic Priority Pollutants in Nearshore Fish from 14 Lake Michigan Tributaries and Embayments, 1983

Composite, nearshore, whole fish samples of selected species, collected in fall 1983 from 13 Lake Michigan tributaries and Grand Traverse Bay, were analyzed for a wide range of pesticides and priority pollutants using gas chromatography-mass spectrometry. This study was carried out to identify existing source areas for known and previously unrecognized toxic substances. Our strategy was to analyze those resident fish with the highest likely levels of contaminants. All fish analyzed (eight species from southern Michigan to the upper peninsula) exceeded the 2 mg/kg FDA action levels for PCBs, while 50% of the samples exceeded the DDTr IJC objective of 1 mg/kg. St. Joseph River common carp (Cyprinus carpio) carried the heaviest contaminant burden of all fish examined for PCBs (27.6 mg/kg), DDTr (10.2 kg/mg), and toxaphene (3.3 mg/kg); chlordane levels (0.85 mg/kg) were second highest to those in Kalamazoo River common carp (0.87 mg/kg). Concentrations of PCBs, toxaphene, DDT, DDE, and other pesticides were higher in bottom-feeding fish, such as common carp, than in top predators, e.g., northern pike (Esox lucius). Bottom feeders are relatively fatty fish, and live and feed near contaminated sediments, which increases their potential to bioaccumulate fat-soluble contaminants. Pesticides were also present in elevated concentrations in fish from sites with higher industrial and agricultural development.

Changes in the abundance of blue-green algae related to nutrient loadings in the nearshore of Lake Michigan

Nutrient loadings to the nearshore of southeastern Lake Michigan have undergone a remarkable reduction. This reduction can affect the nutrient supply and result in biological changes. Changes in phytoplankton community, particularly the blue-green algae, can be related to nutrient changes. After thermal stratification, sudden increases in the blue-green algae population were significantly correlated to soluble reactive phosphorus concentrations. Phosphorus-stimulated low dissolved silica and phosphorus limitations after stratification appear to be primary factors contributing to the success of these algae.

Surficial Sediment Redistribution by Wave Energy: Element—Grain Size Relationships☆

Abstract Dissipation of wave energy as waves begin to feel the lake floor determines grain size variations for the surficial nearshore sediments of southeastern Lake Michigan. Variations of sediment composition mimic those of the silt- and clay-sized sediment fractions. Both grain size and compositional variations can be used to define the nearshore zone in the Great Lakes.

Soluble Element Concentrations and Complexation in Southeastern Lake Michigan

Water samples were collected from the epilimnion and hypolimnion of southeastern Lake Michigan during 1974 and 1975. The mean elemental soluble (< 0.45 μm) concentrations in log10 (moles per liter) of the 88 samples collected from the epilimnion are: Ba = −6.5, Ca = −3.1, Co = −7. 7, Cr = −7.5, Cu = −7.4, Fe =−6.9, K =−4.5, Mg= −3.3, Mn =−8.1, Mo =−6.9, Na =−3.6,Ni = −6.9, Sr=−5.9, Zn =−7.1, Cl = −3.5, soluble reactive PO42−-P = −7.5, SO42− = −3. 7, and soluble reactive SiO2 = −5.3. During the month of July in 1974 and 1975, the only variable having significant concentration differences between the epilimnion and the hypolimnion was soluble reactive SiO2. It was more concentrated in the hypolimnion. Using thermodynamic data and solving simultaneous equations, the degree of complexation of each ion has been estimated. Ions which have 10% or more of their activity accounted for by complexes include Co2+, Cu2+, Fe3+, Mn2+,Ni2+, CO32−, SO42−,and HPO42−. Using the resulting free ion activities and calculating solubility products, epilimnetic lake water during July 1974 from southeastern Lake Michigan is supersaturated with respect to dolomite, malachite, hydroxylapatite, fluorapatite, hydroxoapatite, X-ray amorphous Fe(OH)3, and goethite. It is undersaturated with respect to calcite, aragonite, rhodochrosite, barite, and strengite.

Contamination of Green Bay water with lead and cadmium by a 37-m long, 2-m draft research vessel

During late April 1989, Green Bay, Lake Michigan water was sampled for dissolved concentrations of lead and cadmium. Samples used to document horizontal contamination of the water by a research vessel were collected using a rubber boat rowed 2, 50, 100, and 200 m upwind of the anchored mother ship. Samples used to document vertical contamination of the water column by the research vessel were collected from the vessel at water depths of 0.2, 2, 5, 10, and 20 m. Both lead and cadmium blanks were < 0.5 ng/l and below their limits of detection at the 95% level of confidence of 3.5 and 0.98 ng/l, respectively. Concentrations of lead in the horizontal direction varied between 3.5 ng/1 at 200 m from the ship and 7.7 ng/1 at 2 m from the ship. Cadmium concentrations varied from 2.8 ng/l at 2 m from the ship to 1.5 ng/1 at 200 m from the ship. Lead concentrations in the vertical direction varied between 8.4 ngll at a depth of 0.2 m and 3.3 ng/l at 5 m. Cadmium concentrations ranged between 4.5 ng/l at 2 m and 2.2 ng/1 at 20 m. The vertical studies were inconclusive and appeared to be influenced by resuspension of bottom sediments. Uncontaminated samples can be collected as close as 100 m to the research vessel.

Estimation of Trace Metal Storage in Lake St. Clair Post-Settlement Sediments Using Composite Samples

Abstract Sediment cores were collected from 36 stations in Lake St. Clair during 1985 by divers. Usually within hours of collection, replicate cores were extruded and sectioned into 1-to 2-cm intervals. One replicate was stored by Canada Centre for Inland Waters personnel for organic contaminant, mercury, and major element analyses. The other replicate was stored by Great Lakes Research Division and Great Lakes Environmental Research Laboratory personnel for Cs-137, Pb-210, grain size, total carbon, and trace metal analyses. In order to estimate the mass of trace metals stored in the lake sediments, equal mass sections of each core were composited. These and individual sections of each core were analyzed and the total mass and anthropogenic mass of each metal in culturally impacted sediments were calculated. Estimated total and anthropogenic masses (metric tons) are: bismuth, 27 and 13; cadmium, 690 and 440; chromium, 5,100 and 1,800; copper, 3,000 and 1,500; nickel, 4,000 and 1,300; lead, 3,200 and 1,500; antimony, 25 and 13; and zinc, 11,000 and 3,300.

The influence of phytoplankton composition on the relative effectiveness of grinding and sonification for chlorophyll extraction

The chlorophyll recovery efficiency was compared between control, ground, and sonified samples. The results showed significant improvement between control and ground samples but not between control and sonified samples. Neither prolonging time of sonification nor using an ice bath during filter grinding improved efficiency. Higher chlorophyll a recovery was obtained from ground samples than from sonified ones, when the water samples contained centric diatoms and filamentous blue-green algae. When total phytoplankton numbers were high, there was a distinct advantage in using grinding rather than sonification for chlorophyll c recovery.

Inorganic Chemistry of Particulate Matter from the Nearshore Zone of Lake Michigan

Abstract Particulate matter from a nearshore region of southeastern Lake Michigan serves as a sink for trace metals and a conveyor of trace metals to the sediments. Fe, K, Mg, and Mn are always more concentrated in the hypolimnion than in the epilimnion, and Ca, Cr, Cu, Na, Sr, Zn, and total P are generally more concentrated in the hypolimnion than in the epilimnion. Enrichment of these metals in the hypolimnion particulates is attributed to sediment resuspension. Comparison of trace metal concentrations in the particulates with those in phytoplankton and zooplankton indicates that the plankton are not a significant contributor to the trace metal particulate chemistry of this nearshore region. Significant fractions (33% to nearly 100%) of total Cr, Cu, Fe, Mn, and Zn concentrations in the water column are associated with particulates. During the warmer months, calcium carbonate precipitates. Particulate chemistry changes little with the CaCO 3 formation, with the exception of an increased amount of calcium. Variations in the concentrations of trace metals are controlled either by both dolomite and hydrated manganese oxides or by an unknown phase believed to be organic in nature.

A numerical simulation of trichromatic equations in chlorophyll estimation using the spectrophotometric technique

A numerical simulation of trichromatic pigment equations is made with the aid of a computer utility program. Significant quantitative differences in the estimates of pigment concentration result from using different sets of trichromatic equations. Estimates of chlorophylls a, b, and c were found highly correlated with the application of the equations, even though the absorbance values used as input for the stimulation are not correlated.