scholarly journals The Reproductive Biology of Deep-Sea Elasmobranchs and Batoids from Chatham Rise and the Sub-Antarctic Region of New Zealand

2021 ◽  
Author(s):  
◽  
Adèle Dutilloy

<p>The reproductive biology of thirteen poorly studied deep-sea elasmobranch species, on Chatham Rise and the Sub-Antarctic region of New Zealand, was assessed. The study species are all commonly caught as bycatch in commercial fisheries and include: three viviparous species (Centroselachus crepidater, Centrophorus squamosus, Deania calcea), five deep-sea catsharks (Apristurus spp.), and five deep-sea batoid species. However, due to a lack of knowledge on their general biology, ecology, and taxonomy – the impact of fishing on these species is unknown. A species’ resilience to fishing pressure depends on its biological productivity and susceptibility to capture. Accurate assessment of maturity is critical to understanding productivity and the effects of fishing pressure on fished stocks. Maturity is commonly assessed macroscopically, using a visual assessment that lacks precision and relies on subjective judgement. The wide array of macroscopic maturity assessment keys, used internationally, employ various sets of characteristics to define the same reproductive processes, which can lead to errors and inconsistencies in maturity assessment and parameter estimates (e.g. length-at-maturity), making direct comparisons between studies difficult. Objective reproductive measurements (oviducal gland size, follicle size, uterus width, follicle number and gonad weight) were used to assess the validity and quality of the macroscopic maturity staging key used in New Zealand, towards determining the onset of maturity and accurately distinguishing between macroscopic stages. The results showed that no single measurement gave a clear-cut indicator of maturity and some fish classified as ‘maturing’ were very likely ‘mature’. Uterus width, follicle size and gonadosomatic index values were found to be the most useful attributes in determining the onset of maturity. Uterus width and follicle size were also useful in determining differences between different macroscopic stages, whilst gonadosomatic index values were useful in distinguishing between reproductive strategies. Histological observations, with a particular focus on sperm storage, were also used to inform the quality of macroscopic maturity assignment. Sperm storage was observed for the first time in Centroselachus crepidater, Centrophorus squamosus and Brochiraja asperula. This study successfully highlighted problems in the macroscopic maturity assessment key currently used in New Zealand and proposes an improved, more objective macroscopic staging key. The improved key aims: 1) to assist in distinguishing between maturity stages, particularly between stage 2 (maturing), stage 2 (resting) and stage 6 (post-partum) females, by examining the same key reproductive structures across all macroscopic stages, and 2) to provide more representative maturity data for use in fisheries and demographic models, for more robust assessment of the impacts of fishing pressure on poorly studied deep-sea chondrichthyans.</p>

2021 ◽  
Author(s):  
◽  
Adèle Dutilloy

<p>The reproductive biology of thirteen poorly studied deep-sea elasmobranch species, on Chatham Rise and the Sub-Antarctic region of New Zealand, was assessed. The study species are all commonly caught as bycatch in commercial fisheries and include: three viviparous species (Centroselachus crepidater, Centrophorus squamosus, Deania calcea), five deep-sea catsharks (Apristurus spp.), and five deep-sea batoid species. However, due to a lack of knowledge on their general biology, ecology, and taxonomy – the impact of fishing on these species is unknown. A species’ resilience to fishing pressure depends on its biological productivity and susceptibility to capture. Accurate assessment of maturity is critical to understanding productivity and the effects of fishing pressure on fished stocks. Maturity is commonly assessed macroscopically, using a visual assessment that lacks precision and relies on subjective judgement. The wide array of macroscopic maturity assessment keys, used internationally, employ various sets of characteristics to define the same reproductive processes, which can lead to errors and inconsistencies in maturity assessment and parameter estimates (e.g. length-at-maturity), making direct comparisons between studies difficult. Objective reproductive measurements (oviducal gland size, follicle size, uterus width, follicle number and gonad weight) were used to assess the validity and quality of the macroscopic maturity staging key used in New Zealand, towards determining the onset of maturity and accurately distinguishing between macroscopic stages. The results showed that no single measurement gave a clear-cut indicator of maturity and some fish classified as ‘maturing’ were very likely ‘mature’. Uterus width, follicle size and gonadosomatic index values were found to be the most useful attributes in determining the onset of maturity. Uterus width and follicle size were also useful in determining differences between different macroscopic stages, whilst gonadosomatic index values were useful in distinguishing between reproductive strategies. Histological observations, with a particular focus on sperm storage, were also used to inform the quality of macroscopic maturity assignment. Sperm storage was observed for the first time in Centroselachus crepidater, Centrophorus squamosus and Brochiraja asperula. This study successfully highlighted problems in the macroscopic maturity assessment key currently used in New Zealand and proposes an improved, more objective macroscopic staging key. The improved key aims: 1) to assist in distinguishing between maturity stages, particularly between stage 2 (maturing), stage 2 (resting) and stage 6 (post-partum) females, by examining the same key reproductive structures across all macroscopic stages, and 2) to provide more representative maturity data for use in fisheries and demographic models, for more robust assessment of the impacts of fishing pressure on poorly studied deep-sea chondrichthyans.</p>


2020 ◽  
Author(s):  
Hiran Thabrew ◽  
Karolina Stasiak ◽  
Harshali Kumar ◽  
Tarique Naseem ◽  
Christopher Frampton ◽  
...  

BACKGROUND Approximately 10% to 12% of New Zealand children and young people have long-term physical conditions (also known as chronic illnesses) and are more likely to develop psychological problems, particularly anxiety and depression. Delayed treatment leads to worse physical and mental healthcare, school absence, and poorer long-term outcomes. Recently, electronic health (eHealth) interventions, especially those based on the principles of Cognitive Behavior Therapy (CBT), have been shown to be as good as face-to-face therapy. Biofeedback techniques have also been shown to enhance relaxation during the treatment of anxiety. However, these modalities have rarely been combined. Young people with long-term physical conditions have expressed a preference for well-designed and technologically-based support to deal with psychological issues, especially anxiety. OBJECTIVE This study aimed to co-design and evaluate the (i) acceptability and (ii) usability of a CBT and biofeedback-based, 5-module eHealth game called ‘Starship Rescue’ and (iii) to provide preliminary evidence regarding its effectiveness in addressing anxiety and quality of life in young people with long-term physical conditions. METHODS Starship Rescue was co-designed with children and young people from a tertiary hospital in Auckland, New Zealand. Following this, 24 young people aged 10 to 17 years were enrolled in an open trial, during which they were asked to use the game for an 8-week period. Acceptability of the game to all participants was assessed using a brief, open-ended questionnaire, and more detailed feedback was obtained from a subset of 10 participants via semi-structured interviews. Usability was evaluated via the System Usability Scale (SUS) and device-recorded frequency and duration of access on completion of the game. Anxiety levels were measured prior to commencement, on completion of the game, and 3 months later using the Generalized Anxiety Disorder 7-item scale (GAD-7) and Spence Child Anxiety Scales (SCAS), and at the start of each module and at the end of the game using an embedded Likert/visual analog scale. Quality of life was measured prior to commencement and on completion of the game using the Pediatric Quality of Life Scale (PEDS-QL). RESULTS Users gave Starship Rescue an overall rating of 5.9 out of 10 (range 3-10 and a mean score of 71 out of 100 (SD 11.7; min 47.5; max 90) on the System Usability Scale (SUS). The mean time period for use of the game was just over 11-weeks (78.8 days, 13.5 hours, 40 minutes). Significant reductions in anxiety were noted between the start and end of the game on the GAD-7 (-4.6 (p=0.000)), SCAS (-9.6 (p=0.005)), and the Likert/visual analogue scales (-2.4 (p=0.001)). Quality of life also improved on the PedsQL scale (+4.3 (p=0.042)). All changes were sustained at 3-month follow-up. CONCLUSIONS This study provides preliminary evidence for Starship Rescue being an acceptable, usable and effective eHealth intervention for addressing anxiety in young people with long-term physical conditions. Further evaluation is planned via a more formal randomized controlled trial. CLINICALTRIAL Australian New Zealand Clinical Trials Network Registry (ANZCTR): ACTRN12616001253493p;https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=371443 (Archived by WebCite at http://www.webcitation.org/6sYB716lf)


2010 ◽  
Vol 68 (2) ◽  
pp. 265-280 ◽  
Author(s):  
Johanna J. Heymans ◽  
Kerry L. Howell ◽  
Morag Ayers ◽  
Michael T. Burrows ◽  
John D. M. Gordon ◽  
...  

Abstract Heymans, J. J., Howell, K. L., Ayers, M., Burrows, M. T., Gordon, J. D. M., Jones, E. G., and Neat, F. 2011. Do we have enough information to apply the ecosystem approach to management of deep-sea fisheries? An example from the West of Scotland. – ICES Journal of Marine Science, 68: 265–280. There is currently a global call for more use of an ecosystem approach to fisheries management (EAFM), and ecosystem models such as Ecopath with Ecosim (EwE) are being used to provide a holistic view of ecosystem–fisheries interactions. Although these can be useful for an EAFM, the relative paucity of data available for deep-sea ecosystems raises concerns whether we can effectively apply an EAFM to the deep sea. The deep-sea ecosystem off the west coast of Scotland has been studied for longer and in more detail than most. This study assimilates the significant published and unpublished information available on this ecosystem into an EwE model. The results suggest that there are sufficient data available to construct an ecosystem model, but the quality of the data varies and serious potential sources of error are present in biomass and discard estimates. The assumptions needed to produce a model are varied and must be considered when interpreting the outputs of the model. Ecosystem modelling provides a unique view of the deep-water ecosystem and facilitates hypothesis development concerning predator–prey and inter-fishery interactions. Sharks are used to illustrate the benefits of using an ecosystem model to describe changes in their biomass and their prey species. The results show that both fishing for sharks and fishing for their prey affect the biomass of sharks.


1990 ◽  
Vol 156 (1) ◽  
pp. 84-91 ◽  
Author(s):  
Sarah E. Romans-Clarkson ◽  
Valerie A. Walton ◽  
G. Peter Herbison ◽  
Paul E. Mullen

A random community survey into psychiatric disorder among women in urban and rural New Zealand found urban women to be more often at age extremes, not married, better educated, in more paid employment, and to have better household and child-care facilities. There were no overall urban–rural differences in the GHQ-28 score, total PSE score or PSE case rates. A multiple regression found the same three factors accounted for most of the explained variance in both the urban and the rural total PSE scores: these were the quality of social networks, difficulties with alcohol, and the past experience of childhood sexual abuse. Low socioeconomic status, poor physical health, and adult experiences of sexual and physical abuse were also associated with increased psychiatric morbidity in both samples. Other individual sociodemographic items were correlated with psychiatric morbidity for the urban or rural sample only.


Author(s):  
P. A. Tyler ◽  
J. D. Gage

INTRODUCTIONOphiacantha bidentata (Retzius) is a widespread arctic-boreal ophiuroid with a circumpolar distribution in the shallow waters of the Arctic seas and penetrating into the deep sea of the.North Atlantic and North Pacific (Mortensen, 1927, 1933a; D'yakonov, 1954). Early observations of this species were confined to defining zoogeo-graphical and taxonomic criteria including the separation of deep water specimens as the variety fraterna (Farran, 1912; Grieg, 1921; Mortensen, 1933a). Mortensen (1910) and Thorson (1936, pp. 18–26) noted the large eggs (o.8 mm diameter) in specimens from Greenland and Thorson (1936) proposed that this species had ‘big eggs rich in yolk, shed directly into the sea. Much reduced larval stage or direct development’. This evidence is supported by observations of O. bidentata from the White and Barents Seas (Semenova, Mileikovsky & Nesis, 1964; Kaufman, 1974)..


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