scholarly journals Demography of the largest and most endangered Brazilian parrotfish, Scarus trispinosus, reveals overfishing

2020 ◽  
Vol 41 ◽  
pp. 319-327 ◽  
Author(s):  
NC Roos ◽  
BM Taylor ◽  
AR Carvalho ◽  
GO Longo
Keyword(s):  
Endangered Species ◽  
Fisheries Management ◽  
Life History Traits ◽  
Population Decline ◽  
Reproductive Capacity ◽  
Artisanal Fishing ◽  
Ontogenetic Habitat Shift ◽  
Late Maturity ◽  
Reproductive Cycles ◽  
Late Maturation

Many parrotfishes (Labridae: Scarinae) have life history traits, including late maturation and long lifespans, that make them vulnerable to overfishing. The greenbeak parrotfish Scarus trispinosus is the largest Brazilian endemic parrotfish and has been harvested in reef-associated fisheries along the coast. After a sharp population decline, S. trispinosus is now considered by the IUCN to be an Endangered species. We provide an assessment of age-based and reproductive biology for this species and discuss applications for fisheries management. We sampled 95 individuals from inshore and offshore reefs from Rio Grande do Norte state, northeast Brazil, both obtained from artisanal fishing landings and fishery-independent collections. All sampled specimens were females with fork lengths (FL) ranging from 8.1 to 55.9 cm and ages ranging from 0.3 to 7 yr, with estimated median maturity (L50) of 39.2 cm FL and median age (A50) of 4.2 yr. Size class distributions indicate that the inshore reefs are mostly inhabited by juveniles under L50, whereas the offshore reefs are inhabited by mature individuals, suggesting an ontogenetic habitat shift from inshore to offshore reefs around the timing of maturation. The fishing pressure on this species is concentrated in inshore reefs, therefore mostly on immature individuals, which may be severely affecting the reproductive capacity of this species. This information is useful to guide size-based fisheries management, such as regulating minimum capture size and fishing gears that capture individuals smaller than L50. Managing fisheries of endangered species with late maturity and complex reproductive cycles such as S. trispinosus is imperative to aid recovery.

scholarly journals Fecal Viral Diversity of Captive and Wild Tasmanian Devils Characterized Using Virion-Enriched Metagenomics and Metatranscriptomics

2019 ◽  
Vol 93 (11) ◽  
Author(s):  
Rowena Chong ◽  
Mang Shi ◽  
Catherine E. Grueber ◽  
Edward C. Holmes ◽  
Carolyn J. Hogg ◽  
...  
Keyword(s):  
Endangered Species ◽  
Population Decline ◽  
Significant Risk ◽  
Rabbit Hemorrhagic Disease Virus ◽  
Viral Diversity ◽  
Hemorrhagic Disease ◽  
Tasmanian Devil ◽  
Dna Viruses ◽  
Viral Communities ◽  
Devil Facial Tumor Disease

ABSTRACT The Tasmanian devil is an endangered carnivorous marsupial threatened by devil facial tumor disease (DFTD). While research on DFTD has been extensive, little is known about viruses in devils and whether any are of potential conservation relevance for this endangered species. Using both metagenomics based on virion enrichment and sequence-independent amplification (virion-enriched metagenomics) and metatranscriptomics based on bulk RNA sequencing, we characterized and compared the fecal viromes of captive and wild devils. A total of 54 fecal samples collected from two captive and four wild populations were processed for virome characterization using both approaches. In total, 24 novel marsupial-related viruses, comprising a sapelovirus, astroviruses, rotaviruses, picobirnaviruses, parvoviruses, papillomaviruses, polyomaviruses, and a gammaherpesvirus, were identified, as well as known mammalian pathogens such as rabbit hemorrhagic disease virus 2. Captive devils showed significantly lower viral diversity than wild devils. Comparison of the two virus discovery approaches revealed substantial differences in the number and types of viruses detected, with metatranscriptomics better suited for RNA viruses and virion-enriched metagenomics largely identifying more DNA viruses. Thus, the viral communities revealed by virion-enriched metagenomics and metatranscriptomics were not interchangeable and neither approach was able to detect all viruses present. An integrated approach using both virion-enriched metagenomics and metatranscriptomics constitutes a powerful tool for obtaining a complete overview of both the taxonomic and functional profiles of viral communities within a sample. IMPORTANCE The Tasmanian devil is an iconic Australian marsupial that has suffered an 80% population decline due to a contagious cancer, devil facial tumor disease, along with other threats. Until now, viral discovery in this species has been confined to one gammaherpesvirus (dasyurid herpesvirus 2 [DaHV-2]), for which captivity was identified as a significant risk factor. Our discovery of 24 novel marsupial-associated RNA and DNA viruses, and that viral diversity is lower in captive than in wild devils, has greatly expanded our knowledge of gut-associated viruses in devils and provides important baseline information that will contribute to the conservation and captive management of this endangered species. Our results also revealed that a combination of virion-enriched metagenomics and metatranscriptomics may be a more comprehensive approach for virome characterization than either method alone. Our results thus provide a springboard for continuous improvements in the way we study complex viral communities.

Larval intraspecific competition for food in the European grapevine moth Lobesia botrana

2014 ◽  
Vol 104 (4) ◽  
pp. 517-524 ◽  
Author(s):  
D. Thiéry ◽  
K. Monceau ◽  
J. Moreau
Keyword(s):  
Life History ◽  
Intraspecific Competition ◽  
Life History Traits ◽  
Larval Mortality ◽  
Lobesia Botrana ◽  
Reproductive Capacity ◽  
Strong Increase ◽  
European Grapevine Moth ◽  
Grapevine Moth ◽  
Larval Crowding

AbstractEffective pest management with lower amounts of pesticides relies on accurate prediction of insect pest growth rates. Knowledge of the factors governing this trait and the resulting fitness of individuals is thus necessary to refine predictions and make suitable decisions in crop protection. The European grapevine moth, Lobesia botrana, the major pest of grapes in Europe, is responsible for huge economic losses. Larvae very rarely leave the grape bunch on which they were oviposited and thus cannot avoid intraspecific competition. In this study, we determined the impact of intraspecific competition during the larval stage on development and adult fitness in this species. This was tested by rearing different numbers of larvae on an artificial diet and measuring developmental and reproductive life history traits. We found that intraspecific competition during larval development has a slight impact on the fitness of L. botrana. The principal finding of this work is that larval density has little effect on the life history traits of survivors. Thus, the timing of eclosion, duration of subsequent oviposition, fecundity appears to be more uniform in L. botrana than in other species. The main effect of larval crowding was a strong increase of larval mortality at high densities whereas the probability of emergence, sex ratio, pupal mass, fecundity and longevity of mated females were not affected by larval crowding. Owing to increased larval mortality at high larval densities, we hypothesized that mortality of larvae at high densities provided better access to food for the survivors with the result that more food was available per capita and there were no effect on fitness of survivors. From our results, larval crowding alters the reproductive capacity of this pest less than expected but this single factor should now be tested in interaction with limited resources in the wild.

scholarly journals MENGENAL JENIS HIU APENDIKS II CITES

OSEANA ◽  
2018 ◽  
Vol 43 (4) ◽  
Author(s):  
Fahmi Fahmi
Keyword(s):  
International Trade ◽  
Endangered Species ◽  
Fisheries Management ◽  
Marine Conservation ◽  
The Body ◽  
Similar Appearance

KNOWING SHARKS LISTED IN APPENDIX II CITES. Sharks have become one of major concerns in fisheries management and marine conservation worldwide. Many members of this group are threatened to extinction due to extensive exploitation since few decades ago. Several species of sharks are now listed in the CITES appendices, which controls the international trade for endangered species. Most of them are relatively easy to identify in the field, especially if their fins are still attached. However, few species may difficult to identify correctly due to the similar appearance to other non-CITES species and when the body is not complete anymore. This article aims to give better understanding on how to identify some shark CITES species in detail.

scholarly journals PENDUGAAN POPULASI BEKANTAN (Nasalis larvatus) DI TAMAN WISATA ALAM TANJUNG BELIMBING KECAMATAN PALOH KABUPATEN SAMBAS

2019 ◽  
Vol 7 (4) ◽  
Author(s):  
Selpa Selpa ◽  
Slamet Rifanjani ◽  
Muflihati Muflihati
Keyword(s):  
Nature Conservation ◽  
Endangered Species ◽  
Large Population ◽  
Population Decline ◽  
Primate Species ◽  
Survey Method ◽  
Proboscis Monkey ◽  
Species Status ◽  
Conservation Area ◽  
Nasalis Larvatus

Proboscis monkey (Nasalis larvatus) is an endemic animal of Borneo including protected primate species as an endangered species status. This species listed as an endangered species caused by large population decline and habitat demage continues to threaten the proboscis population. This research was conducted in Taman Wisata Alam Tanjung Belimbing (TWATB) is a nature conservation area that supports the conservation of proboscis monkey. The purpose of this research is to collect the amount of proboscis monkey populations, so as to provide an overview of conservation efforts that must be carried out. The method was used the River Survey method. The result of Proboscis research based on the age level was found consisted average of 5 adult male individuals, 6 adult female individuals, 7 adolescent individuals and 5 childs. Estimation of the population is calculated using the King’s Method. Estimated individuals population is 12 individuals with a density of 25.5 individuals/km2.Keywords: Proboscis monkey, Population, Tanjung Belimbing, Paloh.

Spatiotemporal variation in maturation: a case study with American plaice (Hippoglossoides platessoides) on the Grand Bank off Newfoundland

2020 ◽  
Vol 77 (10) ◽  
pp. 1688-1699
Author(s):  
Nan Zheng ◽  
Matthew Robertson ◽  
Noel Cadigan ◽  
Fan Zhang ◽  
Joanne Morgan ◽  
...  
Keyword(s):  
Life History ◽  
Spatial Variation ◽  
Fisheries Management ◽  
Life History Traits ◽  
Spatial Scales ◽  
Management Strategies ◽  
Spatiotemporal Variation ◽  
Small Scale ◽  
Spatial And Temporal Scales ◽  
Hippoglossoides Platessoides

Fisheries management usually does not explicitly account for spatial variation in life history traits within populations. However, for some stocks this spatial variation may be substantial. We develop a spatiotemporal generalized linear model and fit the model to a long time series of maturation data for American plaice (Hippoglossoides platessoides) on the Grand Bank off Newfoundland and Labrador. The spatiotemporal correlation structure improves estimation of small-scale spatiotemporal variation in maturity across locations and times with limited or few samples. We test how American plaice maturity varies at three different spatial resolutions. We find improvements in model fit when decreasing spatial scales for higher spatial resolution due to high levels of spatial heterogeneity in American plaice maturity at age and size. Modeling variation in life history traits at the appropriate spatial and temporal scales is necessary for understanding population dynamics and developing appropriate fisheries management strategies.

Distribution, abundance and diet of the Indian pangolin (Manis crassicaudata)

2015 ◽  
Vol 65 (1) ◽  
pp. 57-71 ◽  
Author(s):  
Nausheen Irshad ◽  
Tariq Mahmood ◽  
Riaz Hussain ◽  
Muhammad Sajid Nadeem
Keyword(s):  
Endangered Species ◽  
Population Density ◽  
Population Decline ◽  
Significant Decline ◽  
Food Sources ◽  
Patchy Distribution ◽  
Main Prey ◽  
Conservation Measures ◽  
Maximum Elevation ◽  
Prey Items

Endangered species often inhabit specific habitats and are dependent on specific prey. The Indian pangolin (Manis crassicaudata) is an “endangered”, inimitable mammal currently in jeopardy in Pakistan. Very little data are available about its ecology that could serve as baseline for its conservation. In the current study, we investigated the Indian pangolin’s distribution, abundance and diet in four districts of Potohar Plateau. The species was found evenly distributed in two study districts, while it showed patchy distribution in the remaining two districts, and it occurred up to a maximum elevation of 862 m a.s.l. Population density showed a sharp and significant decline over a period of three years from 2010 to 2013. Faecal matter of the species was found to contain remains of ants (head, abdominal parts, legs) as the second-most voluminous component of the droppings, following soil or clay. Remains of other food sources, like termites, bugs, wood and grasses, were found in minor percentages. Our study reveals that the main prey items of Indian pangolins include two species of black ants (Camponotus confucii and Camponotus compressus), and one species of termite (Odontotermis obesus). The recorded population decline indicates that conservation measures may be needed.

scholarly journals Conservation and conflict between endangered desert fishes

2008 ◽  
Vol 4 (6) ◽  
pp. 655-658 ◽  
Author(s):  
Jennifer M Gumm ◽  
Jennifer L Snekser ◽  
Murray Itzkowitz
Keyword(s):  
Endangered Species ◽  
Habitat Restoration ◽  
Evolutionary Dynamics ◽  
Natural Habitat ◽  
Population Decline ◽  
Breeding Habitat ◽  
Desert Fishes ◽  
Breeding Grounds ◽  
Viable Population ◽  
Population Sizes

Conservation of naturally sympatric endangered species requires unique considerations. While impacts of invasive species garner much attention, interactions between endangered species must also be managed. The endangered Leon Springs pupfish, Cyprinodon bovinus , has suffered a population decline due to decreasing natural habitat. As breeding habitat is lost, C. bovinus is also adversely affected by the sympatric, endangered Pecos gambusia, Gambusia nobilis . Here, we document interactions between these species, finding significantly more G. nobilis accumulated at pupfish spawning events than randomly distributed on breeding grounds in the absence of spawning. As a known egg predator, our results suggest that G. nobilis presence at spawnings may further decrease pupfish numbers while also altering the evolutionary dynamics of C. bovinus breeding tactics. Habitat restoration may decrease Gambusia concentrations or influence C. bovinus breeding behaviour and increase the number of territorial males resulting in viable population sizes for both critically endangered fishes.

Management Alternatives and Strategic Planning for Canada's Fisheries

1978 ◽  
Vol 35 (7) ◽  
pp. 1017-1030 ◽  
Author(s):  
William F. Sinclair
Keyword(s):  
Open Access ◽  
Fisheries Management ◽  
Early Recognition ◽  
Economic Consequences ◽  
Reproductive Capacity ◽  
Best Interest ◽  
Fisheries Economics ◽  
Fisheries Resources ◽  
Fisheries Policy ◽  
Management Alternatives

The evils of operating Canada's commercial and recreational fisheries under open-access conditions were known before Confederation. Early recognition of these ills did not lead to an understanding of the basic problems nor to long-term solutions. In the early 1950s the first economic model was developed that articulated the underlying causes of excess capacity and the tendency of overexploitation in open-access fisheries. This was followed by a number of studies that explored the relationship between the biological reproductive capacity of a fishery and the economic consequences of managing publicly owned resources under open-access conditions. This early work provides a general framework from which a number of fisheries management alternatives emerge. Each of six management alternatives, which are implicit in policy for Canada's commercial fisheries, are assessed in terms of political acceptability, administrative feasibility, and effectiveness. It is emphasized that the responsibility of a government fisheries agency is to manage fisheries resources in the best interest of the owners of the resource – the nation's taxpayers. A properly implemented license control system would dissipate, rather than perpetuate, social and economic hardship among fishermen. This misplaced concern for unproven social problems often leads fisheries managers to support programs that sacrifice all the benefits that could be generated from the resource and the resource itself. A management scheme is recommended that encompasses a simple licensing system, a tax or a royalty on catch, and a limited variation of the "Grandfather System." The combination of these three incorporates the main advantages of most management alternatives while avoiding most of their main shortcomings. A carefully implemented program that accounts for economic and biological considerations would improve the efficiency of the industry, improve fishermen's incomes, minimize social disruptions, help to instill an environmental conscience, protect the resource, and induce less, rather than more, government intervention into the free operation of the fishing industry. Probably more important, the program would generate an economic return for the people of Canada. Key words: overcapitalization, open-access fisheries, fisheries economics, fisheries management, fisheries policy, fish licensing, license limitation, fish royalties, tax on fish landings

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