Predatory-Phase Sea Lampreys (Petromyzon marinus) in the Great Lakes

1980 ◽  
Vol 37 (11) ◽  
pp. 2007-2020 ◽  
Author(s):  
B. G. H. Johnson ◽  
William C. Anderson

Incidentally caught predatory-phase sea lampreys were obtained from the commercial fisheries of the Laurentian Great Lakes, together with related catch data, in return for a reward offered to fishermen. Catches of sea lampreys per unit of fishing effort in Lake Superior generally paralleled other indices of sea lamprey abundance. Recently metamorphosed sea lampreys tended to appear early in the season in deepwater fisheries, typically those directed toward cisco (Coregonus spp.), whereas older specimens were taken more often in gear set at shallower depths during summer and fall. The proportion of male sea lampreys in the collections decreased annually between spring and fall, due apparently to a shoreward movement of the males. Large lake trout (Salvelinus namaycush) appeared to be the preferred prey of the sea lamprey. From studies of the stomach contents, sea lamprey feeding activity appeared to reach a peak in late summer or early fall, thereafter declining until the cessation of feeding in early spring. Growth rate reached a maximum in late summer or early fall. Greatest length was attained between January and March, after which a decrease in length was observed. Predatory-phase sea lampreys remained concentrated near the mouths of their parent streams if sufficient numbers of prey were present. Their distribution in the Great Lakes was related to the location of prey.Key words: sea lamprey, predation, Great Lakes fishery


1980 ◽  
Vol 37 (11) ◽  
pp. 1989-2006 ◽  
Author(s):  
Everett Louis King Jr.

Criteria for the classification of marks inflicted by sea lamprey (Petromyzon marinus) into nine categories were developed from laboratory studies in an attempt to refine the classification system used in field assessment work. These criteria were based on characteristics of the attachment site that could be identified under field conditions by unaided visual means and by touching the attachment site. Healing of these marks was somewhat variable and was influenced by the size of lamprey, duration of attachment, severity of the wound at lamprey detachment, season and water temperature, and by other less obvious factors. Even under laboratory conditions staging of some wounds was difficult, especially at low water temperatures. If these criteria are to be used effectively and with precision in the field, close examination of individual fish may be required. If the feeding and density of specific year-classes of sea lampreys are to be accurately assessed on an annual basis, close attention to the wound size (as it reflects the size of the lamprey's oral disc) and character of wounds on fish will be required as well as consideration of the season of the year in which they are observed.Key words: sea lamprey, attack marks, lake trout, Great Lakes



1980 ◽  
Vol 37 (11) ◽  
pp. 1861-1871 ◽  
Author(s):  
John W. Heinrich ◽  
Jerry G. Weise ◽  
Bernard R. Smith

Biological characteristics of adult sea lampreys, Petromyzon marinus, in the Great Lakes changed in response to lamprey and prey abundance and the chemical control program. Sea lampreys collected as early as 1947, through 1978, from southern Lake Superior, northwestern Lake Michigan, the Ocqueoc River and Canadian shore of Lake Huron, and the Humber River of Lake Ontario were analyzed. Generally, abundance of sea lampreys peaked in each lake before the chemical control program began. The annual mean lengths and weights were relatively low when lampreys were abundant and increased as the numbers were reduced by the control efforts. As an indication of the change in sea lamprey weight per unit change in length, annual log10 weight on log10 length equations were solved at the arbitrary length of 410 mm. The values were plotted against years for each lake and interpreted with respect to chemical treatment periods. All slopes were negative before the control period and positive thereafter. Sea lamprey lengths and weights were low when fish stocks in the Great Lakes were near depletion. As salmonids again became abundant through stocking, lampreys grew larger. In Lake Superior, where detailed records on lake trout abundance have been available since 1959, a significant relation exists between the changes in the sea lamprey estimated weight values at 410 mm and in lake trout abundance (P < 0.01). Male sea lampreys were the dominant sex when populations of the parasite were high. A shift to a preponderance of females occurred as lamprey abundance declined.Key words: Petromyzon marinus, Salvelinus namaycush, abundance, sex ratio, weight–length relationship, chemical control



Abstract.—Burbot <em>Lota lota </em>populations collapsed in four of the five Laurentian Great Lakes between 1930 and the early 1960s. Collapses in Lakes Michigan, Huron, and Ontario were associated with sea lamprey <em>Petromyzon marinus </em>predation, whereas the collapse in Lake Erie was likely due to a combination of overexploitation, decreased water quality, and habitat degradation. We examined time series for burbot population density in all five lakes extending as far back as the early 1970s to present time and characterized the long-term trends after the initial collapses. Burbot population density in Lake Superior has remained relatively low and stable since 1978. Recovery of the burbot populations occurred in Lakes Michigan and Huron during the 1980s and in Lake Erie during the 1990s. Control of sea lampreys was a requirement for recovery of burbot populations in these three lakes. Declines in alewife <em>Alosa pseudoharengus </em>abundance appeared to be a second requirement for burbot recovery in Lakes Michigan and Huron. Alewives have been implicated in the decline of certain Great Lakes fish stocks that have pelagic larvae (e.g., burbot) by consuming the pelagic fry and possibly by outcompeting the fry for food. Relatively high populations of adult lake trout <em>Salvelinus namaycush </em>compared to burbot served as a buffer against predation by sea lampreys in Lakes Huron and Erie, which facilitated recovery of the burbot populations there. Although sea lampreys have been controlled in Lake Ontario, alewives are probably still too abundant to permit burbot recovery.



1967 ◽  
Vol 47 (3) ◽  
pp. 251-261 ◽  
Author(s):  
I. J. Bassett ◽  
C. W. Crompton

Results from 17 pollen collecting stations in British Columbia indicate that air-borne pollen of ragweeds and their relatives, the principal causative agents of hay fever in North America, is practically absent throughout the province. Coniferous trees and shrubs such as pines, spruces, firs, cedars, Douglas fir, hemlocks and junipers produce the greater part of the air-borne pollen from March to early July. Pollen from alders, poplars, willows and birches is also prevalent in some areas in the early spring. The peak periods of grass pollen near the United States–Canadian border occur mainly in June and the early part of July, while further north they are about a month later. Of the four types of plantain pollen identified from the different collecting stations, English plantain was the most common, especially in the southwesterly part of the province. Pollen from the lambs’-quarters and amaranth families and wormwoods occurs mainly in the late summer and early fall and is more abundant in the dry interior than along the coast.



2012 ◽  
Vol 141 (6) ◽  
pp. 1697-1710 ◽  
Author(s):  
Alexander M. Clifford ◽  
Matthew Henry ◽  
Roger Bergstedt ◽  
D. Gordon McDonald ◽  
Adam S. Smits ◽  
...  


2011 ◽  
Vol 68 (3) ◽  
pp. 523-533 ◽  
Author(s):  
Lance A. Vrieze ◽  
Roger A. Bergstedt ◽  
Peter W. Sorensen

Stream-finding behavior of adult sea lamprey ( Petromyzon marinus ), an anadromous fish that relies on pheromones to locate spawning streams, was documented in the vicinity of an important spawning river in the Great Lakes. Untreated and anosmic migrating sea lampreys were implanted with acoustic transmitters and then released outside the Ocqueoc River. Lampreys swam only at night and then actively. When outside of the river plume, lampreys pursued relatively straight bearings parallel to the shoreline while making frequent vertical excursions. In contrast, when within the plume, lampreys made large turns and exhibited a weak bias towards the river mouth, which one-third of them entered. The behavior of anosmic lampreys resembled that of untreated lampreys outside of the plume, except they pursued a more northerly compass bearing. To locate streams, sea lampreys appear to employ a three-phase odor-mediated strategy that involves an initial search along shorelines while casting vertically, followed by river-water-induced turning that brings them close to the river’s mouth, which they then enter using rheotaxis. This novel strategy differs from that of salmonids and appears to offer this poor swimmer adaptive flexibility and suggests ways that pheromonal odors might be used to manage this invasive species.



1995 ◽  
Vol 73 (1) ◽  
pp. 83-88 ◽  
Author(s):  
Thomas M. Haggerty ◽  
Jeffrey T. Garner ◽  
George H. Patterson ◽  
Lannis C. Jones Jr.

Two hundred and thirty-three purple wartyback unionids (Cyclonaias tuberculata) were collected approximately monthly over a 31-month period from Kentucky Reservoir (Tennessee river mile 201.3), Tennessee, between August 1988 and February 1991. An equal sex ratio and only one case of hermaphroditism were discovered. Histological examinations showed that spermatogenesis and oogenesis occurred throughout the year except during late summer and early fall. "Typical" spermatogenesis was most evident between May and July. Spawning occurred between early spring (March–April) and late summer (August). Brooding variation among females was shown by the presence of embryos in the suprabranchial chambers and gills between early April and late August. Brooding was short term, as indicated by mature larvae being found in the outer demibranchs between early July and late August. Full demibranchs were never found, possibly indicating that the study took place during years of poor reproductive performance.



1980 ◽  
Vol 37 (11) ◽  
pp. 1895-1905 ◽  
Author(s):  
P. A. Gllderhus ◽  
B. G. H. Johnson

The chemicals 3-trifluoromethyl-4-nitrophenol (TFM) or a combination of TFM and 2′,5-dichloro-4′-nitrosalicylanilide (Bayer 73) have been used to control the sea lamprey (Petromyzon marinus) in the Great Lakes for about 20 yr. These chemicals cause some mortalities of Oligochaeta and Hirudinea, immature forms of Ephemeroptera (Hexagenia sp.), and certain Trichoptera, Simuliidae, and Amphibia (Necturus sp.). The combination of TFM and Bayer 73 may affect some Pelecypoda and Gastropoda, but its overall effects on invertebrates are probably less than those of TFM alone. Granular Bayer 73 is likely to induce mortalities among oligochaetes, microcrustaceans, chironomids, and pelecypods. No evidence exists that the lampricides have caused the catastrophic decline or disappearance of any species. The overall impact of chemical control of sea lampreys on aquatic communities has been minor compared with the benefits derived.Key words: sea lamprey control, Great Lakes, TFM, Bayer 73, aquatic plants, invertebrates, amphibians



1980 ◽  
Vol 37 (11) ◽  
pp. 2133-2145 ◽  
Author(s):  
Carl J. Walters ◽  
Greg Steer ◽  
George Spangler

Sustained yields, declines, and recovery of lake trout (Salvelinus namaycush) can be explained by a simple model that hypothesizes normal population regulation through density dependent body growth, coupled with depensatory lamprey mortality. The model indicates that either lamprey or fishing alone could have caused the Lake Superior decline, though they apparently operated in concert. The presence of depensatory lamprey mortality leads to a "cliff edge" in the system's dynamics, such that catastrophic changes may be repeated in the future. It is not unlikely that Lake Superior is on the verge of a second collapse. Options for dealing with potential disasters include conservative harvesting policies, development of more sensitive monitoring indicators, and modified stocking policies that may speed the coevolution of a viable lamprey/trout association.Key words: lake trout, sea lamprey, simulation, Great Lakes, policy analysis



1980 ◽  
Vol 37 (11) ◽  
pp. 1641-1657 ◽  
Author(s):  
I. C. Potter

Ammocoetes are relatively sedentary burrowing animals. Movement is related to water discharge, temperature, and season, and occurs predominantly downstream and at night. Growth is asymptotic and seasonal. At the end of larval life, the ammocoete ceases to increase markedly in length and starts to accumulate lipid. Length–frequency curves and data on kidney growth indicate that, in relatively stable and productive sites, ammocoetes of long established populations of the landlocked and anadromous sea lamprey take ~ 5 yr to reach metamorphosing length. Many animals probably enter transformation within a further 3 yr. information from an isolated population in the Big Garlic River and from other tributaries of lakes Superior and Michigan, some of which had been treated with larvicide, shows that the onset of metamorphosis can be highly variable and is apparently related to the growth rates and size of larvae. A short larval life is usually associated with a fast growth rate of ammocoetes, as is sometimes found in rivers where the use of larvicide has reduced population density. The landlocked sea lamprey tends to metamorphose at a longer length and at a greater age than other parasitic lampreys. During metamorphosis, which usually begins in the summer, lampreys maintain length but lose weight as a result of mobilization of lipid. The time between initiation of transformation and onset of feeding is generally 4–10 mo. The downstream migration of metamorphosed animals is nocturnal and is influenced by freshwater discharge. Comparisons are drawn between the sex ratios of sea lampreys in the upper Great Lakes and those of other populations.Key words: ammocoete, habitats, growth, mortality, larvicide, lipid, metamorphosis, migration, sex ratio, Great Lakes



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