scholarly journals Risk factors associated with soft-shelled lobsters (Homarus americanus) in southwestern Nova Scotia, Canada

FACETS ◽  
2017 ◽  
Vol 2 (1) ◽  
pp. 15-33 ◽  
Author(s):  
Krishna K. Thakur ◽  
Crawford Revie ◽  
Henrik Stryhn ◽  
Shannon Scott Tibbetts ◽  
Jean Lavallée ◽  
...  
Keyword(s):  
Nova Scotia ◽  
Homarus Americanus ◽  
Eastern Canada ◽  
Related Factors ◽  
Mixed Effect ◽  
Shell Quality ◽  
Factors Associated ◽  
Regression Methods ◽  
Spatio Temporal ◽  
Ecosystem Changes

Soft-shelled lobsters pose economic challenges to the lobster industry due to low meat yields and survivability during holding and transportation. Our objectives were to describe spatio-temporal patterns of soft-shelled lobsters in southwestern Nova Scotia, and identify environmental and lobster-related factors associated with shell quality. We analyzed data obtained from a broad-scale, intensive monitoring project and remotely sensed water temperatures. Mixed-effect logistic regression and linear regression methods analyzed more than 130 000 samples collected between 2004 and 2014. The annual overall prevalence of soft-shelled lobsters ranged from 9% to 38% and varied significantly among fishing areas. Shell quality was influenced by sex and size, and in the 2 months before the fishing season, lower water temperatures (4–6 weeks prior to sampling) were associated with reduced prevalence of soft-shells. High annual variability of soft-shell prevalence, that water temperature alone could not explain, suggests that adjusting fishing seasons, arbitrarily, in two fishing areas will not improve the overall shell quality of landed lobsters. Further research is needed to evaluate the effects of long-term temperature and ecosystem changes on lobster health in eastern Canada.

scholarly journals Spatial and temporal patterns in the sex ratio of American lobsters (Homarus americanus) in southwestern Nova Scotia, Canada

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
S. Koepper ◽  
C. W. Revie ◽  
H. Stryhn ◽  
K. F. Clark ◽  
S. Scott-Tibbetts ◽  
...  
Keyword(s):  
Nova Scotia ◽  
Environmental Factors ◽  
Sex Ratio ◽  
Sex Ratios ◽  
Temporal Patterns ◽  
Homarus Americanus ◽  
Biological Data ◽  
Future Climate Change ◽  
Climate Change Scenarios ◽  
Mixed Effect

AbstractAn approximate 1:1 sex ratio of American lobsters can be skewed due to environmental factors or fisheries management. Substantial skewness can impact mating behaviour and lower reproduction which could have far-reaching ecological and economic consequences. The aim was to investigate the sex ratio patterns of lobsters in two lobster fishing areas (LFAs) in southwestern Nova Scotia, Canada and identify factors associated with skewed sex ratios. This study analyzed biological data from more than 270,000 lobsters sampled over ten years (2010–2019) by the Fishermen and Scientists Research Society. A mixed effect logistic regression model evaluated the effect of spatial, temporal and environmental factors as well as size on the sex ratio of lobsters. There were significant temporal patterns in sex ratios that differed by LFA. After the effects of sampling month, year and LFA were accounted for, lower bottom temperature and deeper water depth were associated with a higher prevalence of females, especially in larger lobsters. We present the first long term analyses of sex ratio patterns in H. americanus in Atlantic Canada’s most commercially important region for this species and provide evidence that these patterns are influenced by environmental factors and fisheries. In view of future climate change scenarios, monitoring the population dynamics of this iconic fishery species is crucial to ensure sustainable fisheries and healthy lobster stocks.

Spatio-temporal patterns and reproductive costs of abnormal clutches of female American lobster, Homarus americanus, in eastern Canada

2018 ◽  
Vol 75 (6) ◽  
pp. 2045-2059 ◽  
Author(s):  
Feng Tang ◽  
Marthe Larsen Haarr ◽  
Bernard Sainte-Marie ◽  
Michel Comeau ◽  
M John Tremblay ◽  
...  
Keyword(s):  
Temporal Patterns ◽  
Population Level ◽  
Homarus Americanus ◽  
American Lobster ◽  
Reproductive Costs ◽  
Eastern Canada ◽  
Catch And Release ◽  
Brooding Period ◽  
Spatio Temporal ◽  
Sampling Times

Abstract Previous studies have documented female American lobster, Homarus americanus, carrying “abnormal clutches”, i.e. with eggs covering less than half of their abdomen. From 2011 to 2014, we worked alongside harvesters to quantify spatio-temporal patterns and reproductive costs of abnormal clutches among 138 738 egg-bearing female lobsters sampled from 193 homeports spread across eastern Canada. Females with abnormal clutches were ubiquitous, being found in 90% of homeports. Their incidence was, however, relatively low, averaging 6% across sampling times and locations. The incidence decreased between spawning and 7–9 months after spawning, potentially due to cases of complete brood failure caused by sperm limitation, and it then increased toward the end of the brooding period, potentially due to repeated catch and release of ovigerous females during the fishery. In most regions, small females were more likely to carry abnormal clutches than larger females. We estimated population-level egg loss between late oogenesis and hatching of embryos at 47–51%, with approximately half being associated with normal clutches and half with abnormal clutches and complete brood failure.

Management of Recurrent or Progressing Skull Base Chondrosarcomas: Predictors of Long-Term Outcomes

2020 ◽  
Author(s):  
Jonathan D. Breshears ◽  
Franco DeMonte ◽  
Ahmed Habib ◽  
Paul W. Gidley ◽  
Shaan M. Raza
Keyword(s):  
Natural History ◽  
Skull Base ◽  
Radiation Treatment ◽  
Systemic Disease ◽  
Primary Treatment ◽  
Salvage Treatment ◽  
Low Grade ◽  
Related Factors ◽  
Factors Associated ◽  
Initial Recurrence

Abstract Background Skull base chondrosarcomas (CSA) are difficult tumors to cure and there is little data regarding salvage therapy. Objective This study aims to identify presentation and treatment-related factors which impact the progression free survival (PFS) and disease specific survival (DSS) for recurrent CSA, and to identify salvage treatment factors associated with successful restoration to the natural history following primary treatment. Methods This single-institution retrospective review included patients with recurrent/progressive CSA over a 25-year period. Survival analysis for factors impacting PFS and DSS was performed. Salvage treatment factors associated with achieving PFS ≥newly diagnosed median PFS were identified using univariate statistics. Analysis was performed on first recurrences and all recurrences combined. Results A total of 47 recurrence/progression events were analyzed from 17 patients (median two events/patient, range = 1–8). The overall PFS and DSS for the initial recurrence was 32 (range = 3–267) and 79 (range = 3–285) months, respectively. Conventional grade III or mesenchymal histology significantly predicted shorter PFS and DSS (p < 0.0001). After stratification by histology, previous radiation predicted shorter PFS for low-grade tumors (p = 0.009). Gross total resection (GTR) after a first time recurrence was significantly associated with successful salvage treatment (p < 0.05); however, this was rare. Conclusion In this series, high grade histology and prior radiation treatment negatively impacted salvage treatment outcomes, while GTR was associated with restoration to natural history following primary treatment. Careful consideration of histology, systemic disease status, previous treatments, and the anatomic extent of the skull base disease can optimize the outcomes of salvage intervention.

scholarly journals Factors Associated with Meeting the Psychosocial Needs of Cancer Survivors in Nova Scotia, Canada

2020 ◽  
Vol 28 (1) ◽  
pp. 13-25
Author(s):  
Soleil Chahine ◽  
Gordon Walsh ◽  
Robin Urquhart
Keyword(s):  
Primary Care ◽  
Nova Scotia ◽  
Cancer Survivors ◽  
Sociodemographic Factors ◽  
Patient Navigator ◽  
Care Providers ◽  
Psychosocial Needs ◽  
Factors Associated ◽  
Follow Up Care

Purpose: The purpose of this study is to describe the psychosocial needs of cancer survivors and examine whether sociodemographic factors and health care providers accessed are associated with needs being met. Methods: All Nova Scotia survivors meeting specific inclusion and exclusion criteria are identified from the Nova Scotia Cancer Registry and sent an 83-item survey to assess psychosocial concerns and whether and how their needs were met. Descriptive statistics (frequencies, percentages) and Chi-square analyses are used to examine associations between sociodemographic and provider factors and outcomes. Results: Anxiety and fear of recurrence, depression, and changes in sexual intimacy are major areas of concern for survivors. Various sociodemographic factors, such as immigration status, education, employment, and internet use, are associated with reported psychosocial health and having one’s needs met. Having both a specialist and primary care provider in charge of follow-up care is associated with a significantly (p < 0.05) higher degree of psychosocial and informational needs met compared to only one physician or no follow-up physician in charge. Accessing a patient navigator also is significantly associated with a higher degree of needs met. Conclusions: Our study identifies the most prevalent psychosocial needs of cancer survivors and the factors associated with having a higher degree of needs met, including certain sociodemographic factors, follow-up care by both a primary care practitioner and specialist, and accessing a patient navigator.

Carabidae (Coleoptera) in Nova Scotia, Canada wild blueberry fields: prospects for biological control

2012 ◽  
Vol 144 (6) ◽  
pp. 779-791 ◽  
Author(s):  
G.C. Cutler ◽  
J.M. Renkema ◽  
C.G. Majka ◽  
J.M. Sproule
Keyword(s):  
Biological Control ◽  
Nova Scotia ◽  
Species Diversity ◽  
Insect Pests ◽  
Abundant Species ◽  
Conservation Biological Control ◽  
Carabid Beetles ◽  
Eastern Canada ◽  
Wild Blueberries ◽  
Wild Blueberry

AbstractThe Carabidae (Coleoptera) are a diverse family of beetles with almost 300 species identified in Nova Scotia, Canada. Carabid beetle communities have been studied in several agricultural systems, but not wild blueberries, an important crop in eastern Canada. In the interest of potentially developing conservation biological control programs in wild blueberry, we collected Carabidae in crop (fruit-bearing) and sprout (vegetative) blueberry fields in Nova Scotia in order to assess species diversity and abundance over space and time. Over 3200 specimens were collected, representing 51 species. A large portion of collected specimens (39%) were nonnative, and the most abundant species were generally predacious and synanthropic. Species diversity tended to be higher near forest edges than further into fields, but not for all abundant species. Several of the most prominent predators showed significant differences in preference of crop versus sprout fields, distribution throughout fields, and seasonable abundance. These findings have implications for conservation biological control efforts with carabid beetles against several insect pests in wild blueberry.

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