Impact of logging and natural fires on fish communities of Laurentian Shield lakes

2000 ◽  
Vol 57 (S2) ◽  
pp. 165-174 ◽  
Author(s):  
Isabelle St-Onge ◽  
Pierre Magnan

The goal of this study was to determine if natural fires and logging have a significant impact on abundance, growth, and size structure of fish populations in 38 lakes of the Laurentian Shield (Québec, Canada). The watersheds of nine of these lakes underwent logging and nine underwent natural fires, while the 20 remaining lakes were used as references. No significant differences were found among the three lake groups in the catch per unit of effort of the most abundant species: white sucker (Catostomus commersoni), northern pike (Esox lucius), yellow perch (Perca flavescens), lake whitefish (Coregonus clupeaformis), fallfish (Semotilus corporalis), brook trout (Salvelinus fontinalis), walleye (Stizostedion vitreum), and burbot (Lota lota). No significant difference was found among control, burned, and logged lakes in the back-calculated length of yellow perch, for which age determinations were made. However, we found that the proportions of small yellow perch and white sucker were significantly lower in populations of impacted lakes (burned and logged lakes pooled). The influence of logging and fires remained significant when a series of biotic and abiotic variables on watershed and lake characteristics were accounted for in multiple regression analyses. The lower proportion of small fish in impacted lakes could be due to an increase in postemergence mortality or to a shift of individuals to the pelagic zone.

1985 ◽  
Vol 63 (12) ◽  
pp. 2882-2884 ◽  
Author(s):  
G. E. Newsome ◽  
Jean Tompkins

The entire seasonal reproductive effort of female yellow perch (Perca flavescens and Perca fluviatilis) is contained in a single, tubular, gelatinous egg mass. Predation on these egg masses is potentially a major mortality factor among perch, although reports of its occurrence are lacking. This suggests the egg masses may be protected by an antipredator mechanism that renders them inedible. In a series of feeding trials, no egg masses were consumed when offered to a number of species considered potential predators (eel, white sucker, brown bullhead, yellow perch, three- and nine-spined sticklebacks), although alternate food items were frequently consumed when provided. Examination of stomach contents of potential predators (eel, white sucker) collected from perch spawning sites at the peak of the reproductive period contained no egg masses. Egg masses were not lethal when ingested by a nonselective test fish, hatchery-reared brook trout, suggesting that an unpalatable rather than a toxic substance protects perch egg masses from predation.


1987 ◽  
Vol 22 (3) ◽  
pp. 352-364
Author(s):  
R. Peterson ◽  
S. Ray

Abstract Brook trout and yellow perch collected while surveying New Brunswick and Nova Scotia headwater lakes were analyzed for DDT metabolites, chlordane, hexacyclohexane isomers, hexachlorobenzene, toxaphene and PCB’s. Concentrations of DDT metabolites were much higher from fish taken from lakes in north-central N.B. (200-700 ng/g wet wt) than from fish taken elsewhere (<10 ng/g). Seventy to 90% of the DDT metabolites was DDE. Chlordane (3-13 ng/g) was analyzed in seven trout, six of them from central N.B. areas with intensive agriculture. Isomers of hexachlorocyclohexane were in highest concentration from north-central N.B. (10-20 ng/g), eastern N.S. (5-15 ng/g) and southern N.B. (5-20 ng/g). In most cases, alpha-hexachlorocyclohexane (lindane) was the isomer in highest concentration. Concentrations of hexachlorobenzene in fish tissues was highly variable with no obvious geographic bias. PCB’s were detected in very few fish, and no toxaphene was detected.


2021 ◽  
Vol 14 ◽  
pp. 194008292110103
Author(s):  
Patrick Jules Atagana ◽  
Eric Moïse Bakwo Fils ◽  
Sevilor Kekeunou

We aimed to assess how bats are affected by habitat transformation by comparing bat assemblages in four habitat types: primary forest, secondary forest, cocoa plantations and human habitations in the Dja Biosphere Reserve of southern Cameroon. Bats were sampled in the four habitat types using mist nets. During 126 nights, a total of 413 bats were captured, belonging to four families, 16 genera and 24 species. Ninety three individuals (17 species) were captured in the primary forest, followed by plantations (105 individuals, 14 species), human habitations (159 individuals, 10 species), and secondary forest (55 individuals, eight species). Megaloglossus woermanni was recorded in all the four habitats, and was the most abundant species (105 individuals). The analysis of bat assemblage between habitat types showed a statistically significant difference in species composition. The distribution of the six most abundant species ( Epomops franqueti, Megaloglossus woermanni, Rousettus aegyptiacus, Dohyrina cyclops, Hipposideros cf. caffer and Hipposideros cf. ruber) was influenced by habitat types. Our results suggest that the decrease in species richness observed in disturbed habitats may be due to habitat perturbations of primary forest habitats. Therefore, it is important to examine the effects of habitat conversion at species level, as responses are often species-specific.


Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1734
Author(s):  
Brenda Sarahí Ramos-Rivera ◽  
Himmer Castro-Mondragon ◽  
José Gabriel Kuk-Dzul ◽  
Pedro Flores-Rodríguez ◽  
Rafael Flores-Garza

The present study contributes to the knowledge of epibionts recorded on sea turtles that nested on a beach in the South Pacific of Mexico. A total of 125 Lepidochelys olivacea turtles nested on Llano Real beach, Guerrero, Mexico, were examined. We collected 450 conspicuous organisms from 8 species from 43 turtles. The corresponding data analysis was carried out to obtain the relative abundance, the relationship between turtle sizes and the presence of organisms, the similarity of species between the sampling months, and the interspecific relationships between the epibionts and the turtles observed. Chelonibia testudinaria was the most abundant species, while Remora remora was the least abundant species. The turtles were divided into six body sections, with the greatest abundance of these organisms located in the head–neck section of turtles, and there was a significant difference in the size of the turtles that presented epibionts and those that did not. C. testudinaria showed greater similarity between sampling months, and the interspecific relationships recorded were commensalism, parasitism, amensalism, and protocooperation. This research contributes the first record of epibionts in L. olivacea nesting in Guerrero, Mexico.


1995 ◽  
Vol 52 (3) ◽  
pp. 464-469 ◽  
Author(s):  
Todd M. Koel ◽  
John J. Peterka

Laboratory-based bioassays were conducted to determine concentrations of sodium-sulfate type salinities that limit the hatching success of several fish species. Survival to hatching (SH) was significantly lower (P < 0.05) in sodium-sulfate type waters from Devils Lake, North Dakota, of ≥ 2400 mg/L total dissolved solids (TDS) than in fresh water of 200 mg/L. In waters of 200, 1150, 2400, 4250, and 6350 mg/L TDS, walleye (Stizostedion vitreum) SH was 41, 38, 7, 1, and 0%; northern pike (Esox lucius) SH was 92, 68, 33, 2, and 0%; yellow perch (Perca flavescens) SH was 88, 70, 73, 0, and 0%; white sucker (Catostomus commersoni) SH was 87, 95, 66, 0, and 0%; common carp (Cyprinus carpio) SH was 71, 69, 49, 63, and 25%.


2009 ◽  
Vol 57 (3) ◽  
pp. 205-214 ◽  
Author(s):  
Rosana Di Mauro ◽  
Fabiana Capitanio ◽  
María Delia Viñas

Two plankton mesh sizes of 67 µm and 220 µm were compared to evaluate their efficiency in the capture of the smallest copepods and appendicularians present in the Buenos Aires coastal area (Argentine Sea). A total of 12 copepod species and one appendicularian species were recorded in this study. The copepods were separated into 4 groups: harpacticoids, cyclopoids, small calanoids and large calanoids and their developmental stages. Among the cyclopoids, Oithona nana was the most abundant species, being 96.29 % underestimated by the 220 µm mesh, whereas Microsetella norvegica dominated the harpacticoids and was captured exclusively by the smaller mesh. Similar results were found for copepodites I-III of small calanoids, whose net sampled underestimation reached 99.70%. On the other hand, no significant difference between meshes was found for adults and copepodites IV-V of small calanoids or any of the developmental stages of large calanoids. A great loss of biomass was observed for O. nana when applying the larger mesh. In regards to the appendicularian Oikopleura dioica, all size ranges below 1,000 µm length were better estimated by the 67 µm mesh in terms of abundance and biomass. Our results clearly show that the 67 µm mesh was more efficient in the capture of early stages of small copepods thus providing a more accurate estimation of the fish larvae prey field.


1990 ◽  
Vol 47 (6) ◽  
pp. 1194-1205 ◽  
Author(s):  
T. E. Reimchen

In a 112-ha bog lake on the Queen Charlotte Islands, British Columbia, small fish comprised the major element in the diet of cutthroat trout (Oncorhynchus clarki). Despite the presence of juvenile salmon and char in the lake, threespine stickleback (Gasterosteus aculeatus) was the most common fish in the diet (99.5%). Foraging activity appeared to be more frequent in littoral than in limnetic regions. Mark–recapture methods indicate an average population of 220 trout and 75 000 adult stickleback. Trout consumed an estimated 308 770 stickleback yearly (145 kg) of which 65% were taken during summer. Seventy-three percent of all fish consumed were young of the year and 2% were adults, the latter representing 4% of the adult population in the lake. There was a 75% reduction in total mortality between successive year classes of stickleback (0,1,2,3 +). This consumption curve, which resembles a typical survivorship curve of fish, is a function of the size-structure of the populations and includes interactions between size availability of stickleback, prey-size preferences of the trout, and length frequency distributions of trout. Total weight of stickleback consumed by trout comprised about 40% of that previously calculated for 16 species of avian piscivores in the lake.


2000 ◽  
Vol 6 (1) ◽  
pp. 81 ◽  
Author(s):  
J. E. May ◽  
B. E. Heterick

This paper reports on the apparent displacement of native and exotic ants from gardens in the Perth Metropolitan region by the coastal brown ant (Pheidole megacephala (Fabricius)). Twelve gardens were sampled, four with P. megacephala present, and eight (the controls) where the ant was judged to be absent. Eight out of the 26 ant species recorded (including the coastal brown ant) were introduced. Ninety-two per cent of pitfall trap contents comprised the four most abundant species: P. megacephala, lridomyrmex chasei (Forel), Tetramorium simillimum (F. Smith) and Paratrechina ?obscura (Mayr). Three of the four P. megacephala-dominated gardens were depauperate of almost all other ant species. The fourth P. megacephala-infested garden had a relatively small number of coastal brown ants (104), and the highest number of ant species was found in that garden. The removal of this outlier garden left an average range of one to three species for the other three P. megacephala-infested gardens. Control gardens had between five and 12 ant species. Total ant abundance ranged from an average of 1 027 per P. megacephala-infested garden (increasing to 1 171 if the outlier garden is removed) to 146 at control gardens. There was a significant difference both in ant richness and ant abundance between the controls and P. megacephala-infested gardens (P < 0.05). This remained the case when figures for coastal brown ants were excluded from calculations.


1985 ◽  
Vol 42 (11) ◽  
pp. 1815-1822 ◽  
Author(s):  
Karl Schwalme ◽  
William C. Mackay ◽  
Dieter Lindner

A vertical slot fishway and two Denil fishways (of 10 and 20% slope) built into a weir on the Lesser Slave River (55°18′N, 115°45′W) were studied from May 12 to June 25, 1984, to determine how effectively these designs pass north-temperate, nonsalmonid fishes. Thousands of spottail shiner (Notropis hudsonius), substantial numbers (> 100) of northern pike (Esox lucius), longnose sucker (Catostomus catostomus), white sucker (Catostomus commersoni), immature yellow perch (Perca flavescens), and lesser numbers of burbot (Lota lota), adult yellow perch, lake whitefish (Coregonus clupeaformis), and trout-perch (Percopsis omiscomaycus) ascended the fishways. Walleye (Stizostedion vitreum) and goldeye (Hiodon alosoides), although probably moving extensively through the river, did not use the fishways. Although high water levels allowed most fish to surmount the weir, of those that chose the fishway, pike strongly preferred to ascend the Denil fishways and the two sucker species preferred to ascend the vertical slot. Therefore, a combination of several different fishways may be required for the most efficient passage of a wide variety of species. Plasma glucose and lactate measurements on pike revealed that ascending the Denil fishways was only moderately stressful for these fish.


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