Publications

Dramatic fluctuations have occurred in the abundance of many species in Lake Erie and its tributary waters in the last century. Some fishes of former economic importance have become commercially extinct. Several species apparently have been extirpated, especially in the tributaries. It is believed that further changes in the abundance of other species will occur in the near future. This

The presence and relative abundance of bottom macrofauna in Lake Ontario are documented. Bottom samples were collected at 24 stations in September 1964. The quantity of organisms and the distribution of some species were affected by depth of water. Samples from the shallower stations (47.5 m or less) yielded an average of 41,631 organisms per mA? whereas the deeper stations (91.5 m or...

Records are presented of Na+, K+, Ca++, SiO2, pH, alkalinity, O2, and specific conductance at 106 stations in Lake Ontario. These data are compared for east-west and surface-subsurface variations. Water quality in Lake Ontario is similar to that in Lake Erie with the exception of dissolved oxygen. The open waters of Lake Ontario had no areas of serious oxygen depletions.

No abstract available.

The major species of diatoms in surface collections from Lake Ontario in September 1964 were Asterionella formosa, Fragilaria crotonensis, and Tabellaris fenestrata. Dominant species in the deep-water samples were Stephanodiscus astraea, S. astraea var. mintula, and F. crotonensis. The diatom flora in surface collections varied among several stations in the eastern end of the lake.

The present report contributes to knowledge of the relative abundance of major groups of benthic invertebrates in western Lake Superior, primarily in the Apostle Islands region. Observations are made on the depth habitation of certain species, and some of the fauna are compared to that in some of the other Great Lakes. Also included is a note on the catch of benthic organisms in a...

Activation analysis may be used to determine quantitatively traces of phosphate in natural waters. Methods based on the reaction 31P(n,γ)32P are subject to interference by sulfur and chlorine which give rise to 32P through n,p and n,α reactions. If the ratio of phosphorus to sulfur or chlorine is small, as it is in most natural waters, accurate analyses by these methods are difficult to...

Of 2427 walleyes (Stizostedion vitreum vitreum (Mitchill)) examined from Lake Erie in 1964–66, no females were mature at ages below III and all were mature at age V. All male walleyes from the eastern basin were mature at age II, and those from the western basin at age III. Females from the western basin matured at a shorter length and a younger age than those from the eastern basin...

Cisco die-offs are common in the summer in certain lakes of northern Indiana and southern Michigan, along the southern boundary of the national distribution of coregonine fishes. Although numerous cisco die-offs have been reported, few, if any, have been accompanied by environmental information at the time of the die-off. On 31 July and 1 August 1968, we investigated a cisco die-off on...

A total of 52,390 oligochaetes were collected from 40 stations in western Lake Erie in spring 1961. The population was composed of two families, Naididae and Tubificidae. Only six species of naidids were found. One, Paranais frici, is apparently new to the list of North American freshwater Naididae. Among the 14 tubificids found, five species of Limnodrilus were most abundant; they...

Studies of age, growth, and maturity were based on 1760 fish collected in western Lake Superior in 1964-65. The body:scale relation was curvilinear and the curve had an intercept of 1.65 inches on the length axis. The weight increased as the 2.85 power of the length. Some fish formed an annulus before May 18 in 1965; all had completed annuli by late September. Longnose suckers grew 3.6...

No abstract available.