Evidence of Migration and Homing of Lobsters (Homarus americanus) on the Scotian Shelf

1986 ◽  
Vol 43 (11) ◽  
pp. 2206-2211 ◽  
Author(s):  
D. S. Pezzack ◽  
D. R. Duggan

In the Browns Bank region of the Scotian Shelf between June 1982 and December 1983, 6285 tagged lobsters (Homarus americanus) were released. Of the 2486 lobsters recaptured, 361 were recaptured more than once. Eight lobsters released in late May to mid-July were recaptured the following spring and summer, with at least one intervening recapture in the fall–winter period. Five of the eight lobsters showed homing tendencies. Two lobsters made long-distance (> 200 km) return migrations, three made short (50–100 km) return migrations, and three moved long distances but did not return. One lobster at large 6 mo and four at large 22–34 mo made long-distance return migrations, moving over 200 km and returning to within 9–42 km of the initial release site. The data indicate that some lobsters undertake long-distance return migration, which returns the lobsters to specific sections of the Shelf.

1989 ◽  
Vol 46 (11) ◽  
pp. 1842-1844 ◽  
Author(s):  
Alan Campbell

Of the 5281 American lobsters (Homarus americanus) tagged and released off McNutt Island, South Nova Scotia, during 1983–87, 15.8% were captured within 3 yr of release. Although most immature (99%) and mature (86%) lobsters were caught < 18.5 km from release, mature lobsters moved a greater mean distance (25.8 km) than immature lobsters (3.6 km). Of the lobsters that moved > 30 km eight moved south to the continental slope near Browns Bank and 11 moved west of Cape Sable to the inshore areas of southwestern Nova Scotia, the midshore area of German Bank and offshore to Browns Bank and Georges Bank. This and other studies of tagged lobsters indicate that there is some movement of lobsters east and west of the Cape Sable area, the southern tip of Nova Scotia, suggesting some mixing between lobster stocks off eastern Nova Scotia and southwestern Nova Scotia. The long distance movement and mixing of mature lobsters suggests that attempts to use tagging information in locating biological boundaries between lobster stocks in the Gulf of Maine, adjoining Continental Shelf, Scotian Shelf and inshore areas of southwestern Nova Scotia and southern end of eastern Nova Scotia may be a difficult task.


2018 ◽  
Vol 131 (3) ◽  
pp. 221-224 ◽  
Author(s):  
Thomas S. Jung ◽  
Nicholas C. Larter

Key objectives of wildlife reintroduction projects should include encouraging post-release site fidelity and high survival rates of founding individuals. Yet, few studies empirically evaluate these performance metrics for released individuals. Bison(Bison bison) restoration is receiving renewed interest by wildlife managers. To inform new bison reintroduction projects, we provide an observation of a 375-km (straight-line distance) post-release movement of three bison bulls from a release site in Yukon, Canada, in 1988. In addition, we note 250-km and 155-km post-release movements of bison in the Northwest Territories, Canada, in 1980 and 1998, respectively. These observations demonstrate the dispersal ability of bison encountering new environments. Wildlife managers planning for new bison reintroductions should consider means to enhance post-release site fidelity to limit long-distance dispersal and mortality and maximize initial population growth.


2014 ◽  
Vol 67 ◽  
pp. 328-328
Author(s):  
B.A. Gresham ◽  
T.M. Withers ◽  
G.A. Avila ◽  
L.A. Berndt

The Australian braconid wasp Cotesia urabae was first released in New Zealand in 2011 as a biological control agent for the gum leaf skeletoniser Uraba lugens (Lepidoptera Nolidae) The larvae of this moth predominantly attack Eucalyptus spp (Class Symphyomyrtus) and since its predicted future geographic range is extensive there is concern it could become a serious pest of eucalypt plantations in New Zealand Initial releases of C urabae using adult parasitoids were made in Auckland at three separate sites between January and June 2011 Cotesia urabae established at each site and preliminary monitoring has revealed that the wasps have naturally dispersed to six other sites ranging up to 6 km from an initial release site In January 2012 C urabae were released in Whangarei and Tauranga trialling a novel method using parasitoidattacked host larvae rather than adult parasitoids This method proved to be successful with establishment now confirmed in both of these locations and also provided greater flexibility The two latest releases were made using the same method in Nelson (October 2013) and Napier (February 2014) but it is not yet known if the parasitoid has successfully established in these locations


2021 ◽  
Vol 118 (17) ◽  
pp. e2013342118
Author(s):  
Katherine J. Leitch ◽  
Francesca V. Ponce ◽  
William B. Dickson ◽  
Floris van Breugel ◽  
Michael H. Dickinson

Despite the ecological importance of long-distance dispersal in insects, its mechanistic basis is poorly understood in genetic model species, in which advanced molecular tools are readily available. One critical question is how insects interact with the wind to detect attractive odor plumes and increase their travel distance as they disperse. To gain insight into dispersal, we conducted release-and-recapture experiments in the Mojave Desert using the fruit fly, Drosophila melanogaster. We deployed chemically baited traps in a 1 km radius ring around the release site, equipped with cameras that captured the arrival times of flies as they landed. In each experiment, we released between 30,000 and 200,000 flies. By repeating the experiments under a variety of conditions, we were able to quantify the influence of wind on flies’ dispersal behavior. Our results confirm that even tiny fruit flies could disperse ∼12 km in a single flight in still air and might travel many times that distance in a moderate wind. The dispersal behavior of the flies is well explained by an agent-based model in which animals maintain a fixed body orientation relative to celestial cues, actively regulate groundspeed along their body axis, and allow the wind to advect them sideways. The model accounts for the observation that flies actively fan out in all directions in still air but are increasingly advected downwind as winds intensify. Our results suggest that dispersing insects may strike a balance between the need to cover large distances while still maintaining the chance of intercepting odor plumes from upwind sources.


1994 ◽  
Vol 72 (10) ◽  
pp. 1700-1710 ◽  
Author(s):  
J. Ward Testa

The movements and diving behavior of 18 adult female Weddell seals (Leptonychotes weddellii) were determined by satellite telemetry during the over-winter period in 1990 and 1991. Nine seals provided diving and movement data for 8 – 9 months. Seals that normally bred in the eastern part of McMurdo Sound spent most of the winter in the middle and northern parts of McMurdo Sound before the annual shore-fast ice had formed in those areas, or in the pack ice 0–50 km north of the sound and Ross Island. This is a greater use of pack ice, as opposed to shore-fast ice, in winter than was previously believed. Some long-distance movements (one over 1500 km in total) to the middle and northwestern parts of the Ross Sea also occurred. Although highly variable within and between individuals, dives indicative of foraging were primarily to mid-water regions (100 – 350 m) in both years, and were similar to those that have been observed in spring and summer, when Pleuragramma antarcticum is the primary prey of Weddell seals in McMurdo Sound.


1985 ◽  
Vol 42 (2) ◽  
pp. 229-238 ◽  
Author(s):  
Alan Campbell ◽  
Aivars B. Stasko

A total of 4304 American lobsters (Homarus americanus) were tagged and released in inshore areas off southwestern Nova Scotia and on northwest Browns Bank during June–August 1975. Of the 424 lobsters recaptured within 5.4 yr of release, 385 had known recapture locations. For all release areas the average straight-line distance traveled by mature ([Formula: see text]carapace length) lobsters (15.6 km) was significantly greater than for immature (59–94 mm carapace length) lobsters (4.7 km). Most (69.3%) of the immature lobsters (N = 212) were recaptured less than 18.5 km (10 naut mi) from the release sites; for mature lobsters (N = 173) this percentage was 40.5%. Previous tagging studies off southwestern Nova Scotia revealed little evidence of long-distance movement; our study, however, shows that mature lobsters can move long distances. Many (19.7%) of the mature lobsters were recaptured more than 92.6 km (50 naut mi) from the release sites. The overall direction of travel was south, in both an east and west direction, with many lobsters moving greater than 50 km from coastal Nova Scotia and Browns Bank into the Gulf of Maine and to the slopes of the continental shelf. Thirteen lobsters moved from Browns Bank to inshore areas of southwestern Nova Scotia. The evidence of the long-distance interchange of a portion of the mature adults between southwestern Nova Scotia and the adjoining continental shelf suggests that lobsters in these areas could belong to a single stock.


Author(s):  
Katherine Leitch ◽  
Francesca Ponce ◽  
Floris van Breugel ◽  
Michael H. Dickinson

AbstractDespite the ecological importance of long-distance dispersal in insects, its underlying mechanistic basis is poorly understood. One critical question is how insects interact with the wind to increase their travel distance as they disperse. To gain insight into dispersal using a species amenable to further investigation using genetic tools, we conducted release-and-recapture experiments in the Mojave Desert using the fruit fly, Drosophila melanogaster. We deployed chemically-baited traps in a 1 km-radius ring around the release site, equipped with machine vision systems that captured the arrival times of flies as they landed. In each experiment, we released between 30,000 and 200,000 flies. By repeating the experiments under a variety of conditions, we were able to quantify the influence of wind on flies’ dispersal behavior. Our results confirm that even tiny fruit flies could disperse ∼15 km in a single flight in still air, and might travel many times that distance in a moderate wind. The dispersal behavior of the flies is well explained by a model in which animals maintain a fixed body orientation relative to celestial cues, actively regulate groundspeed along their body axis, and allow the wind to advect them sideways. The model accounts for the observation that flies actively fan out in all directions in still air, but are increasingly advected downwind as winds intensify. In contrast, our field data do not support a Lévy flight model of dispersal, despite the fact that our experimental conditions almost perfectly match the core assumptions of that theory.Significance StatementFlying insects play a vital role in terrestrial ecosystems, and their decline over the past few decades has been implicated in a collapse of many species that depend upon them for food. By dispersing over large distances, insects transport biomass from one region to another and thus their flight behavior influences ecology on a global scale. Our experiments provide key insight into the dispersal behavior of insects, and suggest that these animals employ a single algorithm that is functionally robust in both still air and under windy conditions. Our results will make it easier to study the ecologically important phenomenon of long-distance dispersal in a genetic model organism, facilitating the identification of cellular and genetic mechanisms.


2010 ◽  
Vol 67 (6) ◽  
pp. 1175-1184 ◽  
Author(s):  
Paul A. Butcher ◽  
Matt K. Broadhurst ◽  
Beverley A. Orchard ◽  
Megan T. Ellis

Abstract Butcher, P. A., Broadhurst, M. K., Orchard, B. A., and Ellis, M. T. 2010. Using biotelemetry to assess the mortality and behaviour of yellowfin bream (Acanthopagrus australis) released with ingested hooks. – ICES Journal of Marine Science, 67: 1175–1184. Biotelemetry was used to test the hypotheses of few impacts to yellowfin bream (Acanthopagrus australis) released with ingested hooks. Sixteen sample fish were tagged and tracked (using 18 receivers), along with 32 controls (16 pre-tagged “C1” and 16 simultaneously tagged “C2” fish) for 112 d in Botany Bay, Australia. All fish survived initial release, but seven tags from two C1, four C2, and one hook-ingested fish remained motionless within the first 6 d, and another 23 fish were last detected near the release site (a fish farm). Most disappearances were attributed to recapture by anglers or predation. The latter fatalities were exacerbated among controls, and they possibly resulted from the confounding effects of confinement, including a loss of fitness. Such effects were limited to the first 4 d; after which all fish had similar movements. Most (98%) subsequent detections were within 1 km of the fish farm, likely attributable to the associated habitat and abundant food. Although all fish remained near structures, 18 fish travelled farther. In addition to providing the first fine-scale information on the movements of yellowfin bream, the study validates releasing hook-ingested individuals with the line cut as a means for minimizing mortality.


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