scholarly journals Distribution and migration of saithe (Pollachius virens) around Iceland inferred from mark-recapture studies

2007 ◽  
Vol 64 (5) ◽  
pp. 1006-1016 ◽  
Author(s):  
Hlynur Armannsson ◽  
Sigurdur Th. Jonsson ◽  
John D. Neilson ◽  
Gudrun Marteinsdottir
Keyword(s):  
Large Scale ◽  
Population Based ◽  
Fishing Effort ◽  
Stock Structure ◽  
Population Parameters ◽  
Long Distance ◽  
Mark Recapture ◽  
History Of ◽  
Migratory Routes ◽  
And Migration

Abstract Armannsson, H., Jonsson, S. Th., Neilson, J. D., and Marteinsdottir, G. 2007. Distribution and migration of saithe (Pollachius virens) around Iceland inferred from mark-recapture studies. – ICES Journal of Marine Science, 64: 1006–1016. Knowledge of the distribution and migration of populations is necessary to identify and conserve stock components and therefore genetic variability. Compared with other gadoid species, little is known about the life history of saithe (Pollachius virens) (known as pollock in the Northwest Atlantic) or its stock components. About 15 800 saithe were tagged near Iceland from 2000 to 2004 to estimate population parameters, to describe saithe dynamics on the Icelandic shelf, and to monitor long-distance migrations, should they occur. A multiplicative model was used to standardize fishing effort to describe the distribution of the tagged population, based on tag returns from the fishery. Saithe have a high affinity to their tagging area, but move considerably within that area. Because of variability in fishing effort among areas, tagged fish exhibit different area-specific catchabilities. The results also indicate seasonal offshore–inshore migrations during summer and variability in migratory routes among different tagging areas related to affinities to different feeding grounds. This could indicate a more complex stock structure than previously thought. Finally, results to date do not indicate large-scale emigration of saithe from Icelandic fishing grounds.

scholarly journals Selecting among Alternative Scenarios of Human Evolution by Simulated Genetic Gradients

Genes ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 506 ◽  
Author(s):  
Catarina Branco ◽  
Miguel Arenas
Keyword(s):  
Human Evolution ◽  
Simulated Data ◽  
Real Data ◽  
Population Admixture ◽  
Evolutionary Processes ◽  
Long Distance ◽  
History Of ◽  
Pros And Cons ◽  
Alternative Scenarios ◽  
And Migration

Selecting among alternative scenarios of human evolution is nowadays a common methodology to investigate the history of our species. This strategy is usually based on computer simulations of genetic data under different evolutionary scenarios, followed by a fitting of the simulated data with the real data. A recent trend in the investigation of ancestral evolutionary processes of modern humans is the application of genetic gradients as a measure of fitting, since evolutionary processes such as range expansions, range contractions, and population admixture (among others) can lead to different genetic gradients. In addition, this strategy allows the analysis of the genetic causes of the observed genetic gradients. Here, we review recent findings on the selection among alternative scenarios of human evolution based on simulated genetic gradients, including pros and cons. First, we describe common methodologies to simulate genetic gradients and apply them to select among alternative scenarios of human evolution. Next, we review previous studies on the influence of range expansions, population admixture, last glacial period, and migration with long-distance dispersal on genetic gradients for some regions of the world. Finally, we discuss this analytical approach, including technical limitations, required improvements, and advice. Although here we focus on human evolution, this approach could be extended to study other species.

scholarly journals A concise review of lobster utilization by worldwide human populations from prehistory to the modern era

2015 ◽  
Vol 72 (suppl_1) ◽  
pp. i7-i21 ◽  
Author(s):  
Ehud Spanier ◽  
Kari L. Lavalli ◽  
Jason S. Goldstein ◽  
Johan C. Groeneveld ◽  
Gareth L. Jordaan ◽  
...  
Keyword(s):  
20Th Century ◽  
18Th Century ◽  
Fishing Effort ◽  
Human Populations ◽  
Ancient Greek ◽  
Long Distance ◽  
Economic Resource ◽  
European Contact ◽  
Long Distance Transport ◽  
History Of

Abstract Lobsters are important resources throughout the world's oceans, providing food security, employment, and a trading commodity. Whereas marine biologists generally focus on modern impacts of fisheries, here we explore the deep history of lobster exploitation by prehistorical humans and ancient civilizations, through the first half of the 20th century. Evidence of lobster use comprises midden remains, artwork, artefacts, writings about lobsters, and written sources describing the fishing practices of indigenous peoples. Evidence from archaeological dig sites is potentially biased because lobster shells are relatively thin and easily degraded in most midden soils; in some cases, they may have been used as fertilizer for crops instead of being dumped in middens. Lobsters were a valuable food and economic resource for early coastal peoples, and ancient Greek and Roman Mediterranean civilizations amassed considerable knowledge of their biology and fisheries. Before European contact, lobsters were utilized by indigenous societies in the Americas, southern Africa, Australia, and New Zealand at seemingly sustainable levels, even while other fish and molluscan species may have been overfished. All written records suggest that coastal lobster populations were dense, even in the presence of abundant and large groundfish predators, and that lobsters were much larger than at present. Lobsters gained a reputation as “food for the poor” in 17th and 18th century Europe and parts of North America, but became a fashionable seafood commodity during the mid-19th century. High demand led to intensified fishing effort with improved fishing gear and boats, and advances in preservation and long-distance transport. By the early 20th century, coastal stocks were overfished in many places and average lobster size was significantly reduced. With overfishing came attempts to regulate fisheries, which have varied over time and have met with limited success.

Mixing and migration of overwintering Atlantic cod (Gadus morhua) stocks near the mouth of the Gulf of St. Lawrence

1999 ◽  
Vol 56 (10) ◽  
pp. 1873-1881 ◽  
Author(s):  
S E Campana ◽  
G A Chouinard ◽  
J M Hanson ◽  
A Fréchet
Keyword(s):  
Large Scale ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
Fishing Effort ◽  
Trace Element Composition ◽  
Eastern Canada ◽  
Management Area ◽  
Elemental Fingerprint ◽  
And Migration ◽  
Southern Flank

Millions of Atlantic cod (Gadus morhua) migrate distances of up to 500 km each fall to aggregate together in a small overwintering area off eastern Canada. Synoptic research vessel surveys carried out each January between 1994 and 1997 documented dense aggregations of cod along both flanks of the Laurentian Channel in each year, with estimated biomasses exceeding 100 000 metric tons. Using the trace element composition of the otolith ("otolith elemental fingerprint") as a natural tag, we found members of four populations to be present on the overwintering grounds in significant numbers, yet large-scale mixing among the populations was minimal. Individual trawl samples were often composed of a single population, suggesting that population integrity was maintained at a scale of <20 km. Cod from the southern Gulf of St. Lawrence dominated the population composition along the southern flank of the Channel, while cod from the northern Gulf dominated the northern flank; the distributions of both of these populations extended well to the east of their summer habitats and were remarkably similar across years. There was no evidence of large-scale mixing across the Channel. In light of the substantive migration of northern Gulf cod into the management area for the southern Newfoundland population, fishing effort off southern Newfoundland has the potential to reduce the size of the northern Gulf population.

scholarly journals Pollock (Pollachius virens) stock structure in the Canadian Maritimes inferred from mark-recapture studies

2006 ◽  
Vol 63 (4) ◽  
pp. 749-765 ◽  
Author(s):  
John D. Neilson ◽  
Wayne T. Stobo ◽  
Peter Perley
Keyword(s):  
Gulf Of Maine ◽  
Atlantic Coast ◽  
Fishing Effort ◽  
Management Unit ◽  
Bay Of Fundy ◽  
Stock Structure ◽  
Scotian Shelf ◽  
Current Management ◽  
Mark Recapture ◽  
Novel Method

Abstract The current management unit for pollock on the Canadian Atlantic coast is large compared with other gadoid resources, and includes the Scotian Shelf, the Bay of Fundy, and the Canadian portion of Georges Bank. Based on an analysis of mark-recapture studies conducted in the Canadian Maritimes and off southwestern Newfoundland and a review of other published studies providing data relevant to stock identification, the stock structure of pollock in Canadian Atlantic waters was re-assessed. The analysis also includes a novel method for using the spatial distribution of standardized fishing effort to predict the distribution of tag returns. It is concluded that three stocks co-occur within the current management unit. The larger population components exist in the western Scotian Shelf (including the eastern Bay of Fundy) and on the eastern Scotian Shelf. There is a coastal population in the western Gulf of Maine that overlaps into Canadian waters, but its size is likely to be relatively small. There is a need to revise the current management unit boundaries to protect the eastern Scotian Shelf stock, which on the basis of growth rate data, appears to be the least productive component of the pollock resource in Canadian Atlantic waters.

scholarly journals The State of Migratory Landbirds in the East Asian Flyway: Distributions, Threats, and Conservation Needs

2021 ◽  
Vol 9 ◽  
Author(s):  
Ding Li Yong ◽  
Wieland Heim ◽  
Sayam U. Chowdhury ◽  
Chang-Yong Choi ◽  
Pavel Ktitorov ◽  
...  
Keyword(s):  
Conservation Status ◽  
East Asian ◽  
Ecological Niches ◽  
Long Distance ◽  
Ecological Requirements ◽  
Wintering Ecology ◽  
Migratory Routes ◽  
And Migration ◽  
Farming Landscapes ◽  
Wide Population

With nearly 400 migratory landbird species, the East Asian Flyway is the most diverse of the world’s flyways. This diversity is a consequence of the varied ecological niches provided by biomes ranging from broadleaf forests to arctic tundra and accentuated by complex biogeographic processes. The distribution and migration ecology of East Asian landbirds is still inadequately known, but a recent explosion in the number of studies tracking the migration of raptors, cuckoos, kingfishers and passerines has greatly increased our knowledge about the stopover and wintering ecology of many species, and the migratory routes that link northeast Eurasia and the Asian tropics. Yet the East Asian Flyway also supports the highest number of threatened species among flyways. Strong declines have been detected in buntings (Emberizidae) and other long-distance migrants. While the conservation of migratory landbirds in this region has largely focused on unsustainable hunting, there are other threats, such as habitat loss and increased agro-chemical use driven directly by land cover change and climate-related processes. Important knowledge gaps to be addressed include (1) threats affecting species in different parts of their annual cycle, (2) range-wide population trends, (3) ecological requirements and habitat use during the non-breeding season, and (4) the conservation status of critical wintering sites (including understudied farming landscapes, such as rice fields) and migration bottlenecks along the flyway.

scholarly journals Seroprevalence of SARS-CoV-2 antibodies in Saint Petersburg, Russia: a population-based study

2020 ◽  
Author(s):  
Anton Barchuk ◽  
Dmitriy Skougarevskiy ◽  
Kirill Titaev ◽  
Daniil Shirokov ◽  
Yulia Raskina ◽  
...  
Keyword(s):  
Response Bias ◽  
Large Scale ◽  
Smoking Status ◽  
Antibody Test ◽  
Population Based ◽  
Individual Characteristics ◽  
Computer Assisted ◽  
Blood Samples ◽  
Saint Petersburg ◽  
History Of

BackgroundEstimates from initial SARS-CoV-2 serological surveys were likely to be biased due to convenience sampling whereas large-scale population-based serosurveys could be biased due to non-response. This study aims to estimate the seroprevalence of SARS-CoV-2 infection in Saint Petersburg, Russia accounting for non-response bias.MethodsWe recruited a random sample of adults residing in St. Petersburg with random digit dialling. Computer-assisted telephone interview was followed by an invitation for an antibody test with randomized rewards for participation. Blood samples collected between May 27, 2020 and June 26, 2020 were assessed for anti-SARS-CoV-2 antibodies using two tests — CMIA and ELISA. The seroprevalence estimates were corrected for non-response bias, test sensitivity, and specificity. Individual characteristics associated with seropositivity were assessed.Findings66,250 individuals were contacted, 6,440 adults agreed to be interviewed and were invited to participate in the serosurvey. Blood samples were obtained from 1038 participants. Naïve seroprevalence corrected for test characteristics was 9.0% [95% CI 7.2–10.8] by CMIA and 10.8% [8.8–12.7] by ELISA. Correction for non-response bias decreased seroprevalence estimates to 7.4% [5.7–9.2] for CMIA and to 9.3% [7.4–11.2] for ELISA. The most pronounced decrease in non-response bias-corrected seroprevalence was attributed to the history of any illnesses in the past 3 months and COVID-19 testing. Besides that seroconversion was negatively associated with smoking status, self-reported history of allergies and changes in hand-washing habits.InterpretationThese results suggest that even low estimates of seroprevalence in Europe’s fourth-largest city can be an overestimation in the presence of non-response bias. Serosurvey design should attempt to identify characteristics that are associated both with participation and seropositivity. Further population-based studies are required to explain the lower seroprevalence in smokers and participant reporting allergies.FundingPolymetal International plc

scholarly journals Concentration of a widespread breeding population in a few critically important nonbreeding areas: Migratory connectivity in the Prothonotary Warbler

The Condor ◽  
2019 ◽  
Vol 121 (2) ◽  
Author(s):  
Christopher M Tonra ◽  
Michael T Hallworth ◽  
Than J Boves ◽  
Jessie Reese ◽  
Lesley P Bulluck ◽  
...  
Keyword(s):  
Annual Cycle ◽  
Large Scale ◽  
Light Level ◽  
Breeding Population ◽  
Migratory Bird ◽  
Migratory Connectivity ◽  
Long Distance ◽  
Breeding Range ◽  
Migratory Routes ◽  
Prothonotary Warbler

Abstract One of the greatest challenges to informed conservation of migratory animals is elucidating spatiotemporal variation in distributions. Without such information, it is impossible to understand full-annual-cycle ecology and effectively implement conservation actions that address where and when populations are most limited. We deployed and recovered light-level geolocators (n = 34) at 6 breeding sites in North America across the breeding range of a declining long-distance migratory bird, the Prothonotary Warbler (Protonotaria citrea). We sought to determine migratory routes, stopover location and duration, and the location of overwintering grounds. We found that the species exhibits a large-scale, east‒west split in migratory routes and weak migratory connectivity across its range. Specifically, almost all individuals, regardless of breeding origin, overlapped in their estimated wintering location in northern Colombia, in an area 20% the size of the breeding range. Additionally, most of the individuals across all breeding locations concentrated in well-defined stopover locations in Central America while en route to Colombia. Although error inherent in light-level geolocation cannot be fully ruled out, surprisingly much of the estimated wintering area included inland areas even though the Prothonotary Warbler is considered a specialist on coastal mangroves in winter. Based on these results, conservation efforts directed at very specific nonbreeding geographical areas will potentially have benefits across most of the breeding population. Our findings highlight the importance of using modern technologies to validate assumptions about little-studied portions of a species’ annual cycle, and the need to distribute sampling across its range.

scholarly journals A brief history of lumpfishing, assessment, and management across the North Atlantic

2018 ◽  
Vol 76 (1) ◽  
pp. 181-191 ◽  
Author(s):  
James Kennedy ◽  
Caroline M F Durif ◽  
Ann-Britt Florin ◽  
Alain Fréchet ◽  
Johanne Gauthier ◽  
...  
Keyword(s):  
Large Scale ◽  
Mesh Size ◽  
Management Plan ◽  
Fishing Effort ◽  
Total Allowable Catch ◽  
Cyclopterus Lumpus ◽  
The North ◽  
Size Number ◽  
The Status ◽  
History Of

Abstract This report documents the fishery, assessment, and management of lumpfish (Cyclopterus lumpus) across its distribution range. Targeting lumpfish for their roe on a large scale began in the 1950s in Iceland and Norway and then in Canada in the 1970s and Greenland in the 1990s. When the fishery began, there were few regulations, but limits on vessel size, mesh size, number of nets, and length of the fishing season were gradually implemented over time. Worldwide landings have varied from ca. 2000 to 8000 tonnes of roe between 1977 and 2016. Iceland and Canada accounted for &gt;80% of the landings until 2000. After 2013, Greenland and Iceland accounted for &gt;94%. All countries except Iceland show a decreasing trend in the number of boats participating in the fishery, which is related to several factors: the monetary value of the roe, changes in the abundance of lumpfish, and increasing age of artisanal fishers. Each country has a different combination of data available for assessment from basic landings and fishing effort data to more detailed fishery independent survey indices of abundance. The management of total catch also differs, with an effort-controlled fishery in Iceland and Canada, a total allowable catch (TAC) per boat in Norway, and TAC per area in Greenland. Population abundance is above management targets in Iceland and Norway, but the status is less clear in Greenland and around Denmark/Sweden and appears to be depleted around Canada. Certification by the Marine Stewardship Council was instrumental in the adoption of a management plan in Greenland; however, benefits to the fishers remain unclear. Aspects surrounding the biology of lumpfish, which is poorly understood and requires investigation, include growth rate, natural mortality, and population differentiation. In addition, there is concern about the potential impacts that the recent escalation in production of lumpfish for use as cleaner fish in the aquaculture industry could have on the wild population.

scholarly journals Will reconnecting ecosystems allow long-distance mammal migrations to resume? A case study of a zebra Equus burchelli migration in Botswana

Oryx ◽  
2011 ◽  
Vol 45 (2) ◽  
pp. 210-216 ◽  
Author(s):  
H.L.A. Bartlam-Brooks ◽  
M.C. Bonyongo ◽  
Stephen Harris
Keyword(s):  
Large Scale ◽  
Long Distance ◽  
North West ◽  
Ecosystem Connectivity ◽  
Ecosystem Fragmentation ◽  
Equus Burchelli ◽  
Future System ◽  
Physical Barriers ◽  
Migratory Routes

AbstractTerrestrial wildlife migrations, once common, are now rare because of ecosystem fragmentation and uncontrolled hunting. Botswana historically contained migratory populations of many species but habitat fragmentation, especially by fences, has decreased the number and size of many of these populations. During a study investigating herbivore movement patterns in north-west Botswana we recorded a long-distance zebra Equus burchelli antiquorum migration between the Okavango Delta and Makgadikgadi grasslands, a round-trip distance of 588 km; 55% of 11 animals collared in the south-eastern peripheral delta made this journey. This was unexpected as, between 1968 and 2004, the migration could not have followed its present course because of the bisection of the route by a veterinary cordon fence. As little evidence exists to suggest that large-scale movements by medium-sized herbivores can be restored, it is of significant interest that this migration was established to the present highly directed route within 4 years of the fence being removed. The success of wildlife corridors, currently being advocated as the best way to re-establish ecosystem connectivity, relies on animals utilizing novel areas by moving between the connected areas. Our findings suggest that medium-sized herbivores may be able to re-establish migrations relatively quickly once physical barriers have been removed and that the success of future system linkages could be increased by utilizing past migratory routes.

scholarly journals Atrial Fibrillation in Patients with Acute Pulmonary Embolism: Clinical Significance and Impact on Prognosis

2019 ◽  
Vol 2019 ◽  
pp. 1-5 ◽  
Author(s):  
Katarzyna Ptaszynska-Kopczynska ◽  
Izabela Kiluk ◽  
Bozena Sobkowicz
Keyword(s):  
Atrial Fibrillation ◽  
Pulmonary Embolism ◽  
Large Scale ◽  
Negative Impact ◽  
Previous History ◽  
Cardiovascular Death ◽  
Population Based ◽  
Embolic Material ◽  
Vein Thrombosis ◽  
History Of

Pulmonary embolism (PE) is one of the most common causes of cardiovascular death. The most often PE etiology is a deep vein thrombosis (DVT) of the lower extremities, but embolic material can arise in pelvic or upper extremity veins as well as in right heart chambers. There is growing number of evidences of atrial fibrillation (AF) involvement in PE. The presence of AF in patients with PE may be both the cause and the consequence of PE. The PE association with AF should be considered in patients without confirmed DVT and with history of AF, which itself is associated with prothrombotic state. The valuable diagnostic method is echocardiography that may bring the insight into source of embolic material. Another possible AF and PE association is the AF as a consequence of an abrupt increase in pulmonary vascular resistance due to the occlusion of the pulmonary vessels. Large-scale population-based studies have provided a considerable body of evidence on the involvement of PE in the onset of subsequent AF. Another important issue is the influence of AF on prognosis in patients with PE. Most investigators demonstrated a negative impact of AF on mortality. The main problem to resolve is whether AF is an independent mortality risk factor or whether it occurs as a result of comorbidities or the severity of a PE episode. Although the pathophysiological basis of this bidirectional relationship exists, many questions are still unresolved and require further studies, including the significance of paroxysmal AF accompanying an acute PE episode, the usefulness of PE risk scales in patients with concomitant AF, and the effect of anticoagulant treatment on PE and AF occurrence. Regardless of the type of AF, clinicians should be alert to the possibility of PE in patients with previous history of AF or presenting with new-onset AF.

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