Biological Knowledge of Thornback Ray (Raja clavata) from the Azores: Improving Scientific Information for the Effectiveness of Species-Specific Management Measures

Elasmobranchs are globally recognized as vulnerable due to their life-history characteristics, fishing pressure, and habitat degradation. Among the skates and rays caught by commercial fisheries, the thornback ray Raja clavata is one of the most economically important in Northwest European seas. However, the scarcity of biological knowledge about this species in Azorean waters has limited the stock assessment types that can be conducted. To improve information on its habitat preferences, spatial distribution and movement pattern, growth, sex ratio, mortality, and reproduction, as well as to investigate long-term changes in abundance and size, this study analyzed approximately 25 years of fishery-dependent and independent data from the Azores. Raja clavata was mainly caught at depths up to 250 m. Most of the tagged fish were recaptured near the release point. A larger–deeper trend was found, and females were larger and more abundant than males. Life-history parameters showed that R. clavata has a long lifespan, large size, slow growth, and low natural mortality. The sustainability of its population is of concern to fisheries management and, while our findings suggested a relatively healthy stock in the Azores, a thorough increase in data quality is required to better understand the stock condition and prevent overexploitation.

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A stepwise stochastic simulation approach to estimate life history parameters for data-poor fisheries

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/cjfas-2015-0303 ◽

2016 ◽

Vol 73 (12) ◽

pp. 1874-1884 ◽

Cited By ~ 12

Author(s):

Marc O. Nadon ◽

Jerald S. Ault

Keyword(s):

Life History ◽

Stock Assessment ◽

Probability Distributions ◽

Size Composition ◽

History Data ◽

Life History Parameters ◽

Life History Data ◽

Novel Approach ◽

Cost Efficient ◽

Species Specific

Coastal fisheries are typically characterized by species-rich catch compositions and limited management resources, which typically leads to notably data-poor situations for stock assessment. Some parsimonious stock assessment approaches rely on cost-efficient size composition data, but these also require estimates of life history parameters associated with natural mortality, growth, and maturity. These parameters are unavailable for most exploited stocks. Here, we present a novel approach that uses a local estimate of maximum length and statistical relationships between key life history parameters to build multivariate probability distributions that can be used to parameterize stock assessment models in the absence of species-specific life history data. We tested this approach on three fish species for which empirical length-at-age and maturity data were available (from Hawaii and Guam) and calculated probability distributions of spawning potential ratios (SPR) at different exploitation rates. The life history parameter and SPR probability distributions generated from our data-limited analytical approach compared well with those obtained from bootstrap analyses of the empirical life history data. This work provides a useful new tool that can greatly assist fishery stock assessment scientists and managers in data-poor situations, typical of most of the world’s fisheries.

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Life History and Ecology of Bluenose Warehou (Hyperoglyphe antarctica, Centrolophidae) in the Southern Atlantic

Frontiers in Marine Science ◽

10.3389/fmars.2021.610172 ◽

2021 ◽

Vol 8 ◽

Author(s):

James B. Bell ◽

Vladimir Laptikhovsky ◽

David K. A. Barnes ◽

Ramon Benedet ◽

Amelia E. Bridges ◽

...

Keyword(s):

Life History ◽

United Kingdom ◽

Cold Water ◽

Stock Assessment ◽

Habitat Preferences ◽

Longline Fishery ◽

Target Species ◽

Commercial Fish ◽

Life History Data ◽

The United Kingdom

Bluenose warehou (Hyperoglyphe antarctica) is a popular commercial fish in Australia and New Zealand, but its biology and ecology are very poorly known in other regions where it is found. We present here the first life history data for this species from the south Atlantic, focusing upon the exclusive economic zone (EEZ) of the United Kingdom Overseas Territory (UKOT) of Tristan da Cunha (TdC). Here, bluenose is known from several seamounts and island margins, typically occurring in waters between 200 and 1,000 m depth and is the target species of trawl and longline fishery operating since 1997. We use a suite of methods to describe important life history parameters, including length-weight and age-length relationships and size at recruitment, as well as examining commercial longline survey data to uncover habitat preferences of bluenose. This work has formed an important part of the United Kingdom government’s Blue Belt Program in TdC. It has underpinned the development of the first stock assessment for this species in the Atlantic, as well as a range of improved conservation measures for some of the more vulnerable species that occur in these areas, including seabirds and cold-water corals.

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Preliminary observations on the life history and movements of skates (Rajidae) around the Island of Jersey, western English Channel

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315410001906 ◽

2010 ◽

Vol 91 (6) ◽

pp. 1185-1192 ◽

Cited By ~ 16

Author(s):

J.R. Ellis ◽

G. Morel ◽

G. Burt ◽

S. Bossy

Keyword(s):

Life History ◽

Sex Ratio ◽

Site Fidelity ◽

Current Knowledge ◽

Stock Structure ◽

English Channel ◽

Thornback Ray ◽

Raja Clavata ◽

High Site ◽

Release Area

The most frequently caught skate species around Jersey include blonde ray Raja brachyura, undulate ray Raja undulata, small-eyed ray Raja microocellata and thornback ray Raja clavata. Between September 2006 and December 2008, a total of 814 individuals were tagged and released, of which 64% were small-eyed ray, 22.6% blonde ray and 12.4% undulate ray. The size distribution, sex-ratio and maturity of these samples are summarized. There were 138 reported recaptures (return rate = 17.1%), with most fish recaptured from the study area. Indeed, many of the tagged skates were recaptured within the same release area or within 20 km, indicating high site fidelity, with the longest distance travelled only 61 km. Thirteen fish were recaptured on multiple (2–4) occasions. To date the longest time at liberty has been 754 days. These results are discussed in relation to our current knowledge of the stock structure and exploitation of skates in the western English Channel.

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Life in the Slow Lane: Ecology and Conservation of Long-Lived Marine Animals

Life in the Slow Lane: Ecology and Conservation of Long-Lived Marine Animals ◽

10.47886/9781888569155.ch18 ◽

1999 ◽

Author(s):

Keyword(s):

Life History ◽

Habitat Degradation ◽

Stock Assessment ◽

Population Analysis ◽

Reproductive Potential ◽

Reef Fishes ◽

The United States ◽

Marine Fishery ◽

Temperate Reef ◽

Size Limits

<em>Abstract.</em> —Effective fisheries management requires considerable information on life history characteristics, recruitment dynamics, habitat requirements, and fishery interactions for the managed species. It is clear that we have little of this information for any of the myriad temperate reef fishes managed in the South Atlantic or Gulf of Mexico regions, not only from our reliance on size limits, controlled effort, or limited harvest but from the repeated failures of all but complete closures of fisheries to allow recovery from overexploitation. Several of the life history features that reef fish share render them particularly vulnerable to both fishing pressure and habitat degradation, including their longevity, their slow maturation, their spatially and temporally predictable spawning aggregations, and the reliance of juveniles on estuarine nursery grounds. In addition, traditional hindcasting methods like virtual population analysis and the use of spawningpotential ratio to diagnose overfishing have not proved reliable means of assessing population status. Virtually unexplored in the United States to date are (1) use of marine fishery reserves to protect demographics and reproductive potential of exploited species, habitat and community structure of all species, and biodiversity and (2) use of forecasting methods of stock assessment based on juvenile abundances. We discuss the ability of these methods to provide insurance against management error and to predict fishery abundances for future year classes, respectively.

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Numerical approach for evaluating impacts of biological uncertainties on estimates of stock–recruitment relationships in elasmobranchs: example of the North Pacific shortfin mako

ICES Journal of Marine Science ◽

10.1093/icesjms/fsz210 ◽

2019 ◽

Vol 77 (1) ◽

pp. 200-215

Author(s):

Mikihiko Kai

Keyword(s):

Life History ◽

North Pacific ◽

Stock Assessment ◽

Numerical Approach ◽

Biological Knowledge ◽

Mean Values ◽

Life History Parameters ◽

Shortfin Mako ◽

Stock Recruitment ◽

The Mean

Abstract Impacts of biological uncertainties on estimates of stock–recruitment relationships (SRRs) in elasmobranchs such as lamniform sharks were evaluated using a numerical approach based on an age-structured model considering reproductive ecology in elasmobranchs. The values of steepness were estimated using several combinations of life history parameters for North Pacific shortfin mako to elucidate whether the numerical approach could identify reasonable values for fundamental life history parameters as well as steepness. The results of the numerical approach indicated that the mean values of steepness and their 95% confidence intervals were highly sensitive to combinations of values for growth rate, maturity ogive, longevity, reproductive cycle, and natural mortality rate. Meanwhile, the most plausible combinations of the biological parameters and values of steepness were identified based on the numerical approach with biological knowledge. The mean values and their standard deviation (SD) for steepness with the Beverton-Holt-SRR model were 0.353 (SD=0.057) and 0.273 (SD=0.046) for 2- and 3-year reproductive cycles, respectively. The numerical approach therefore has high potential to become an important tool for estimating SRR in elasmobranchs such as lamniform sharks, and the application of this approach to other elasmobranchs could greatly contribute to improvements in stock assessment and management.

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Morphological abnormality in thornback ray Raja clavata in the Irish Sea

Environmental Biology of Fishes ◽

10.1007/s10641-021-01105-8 ◽

2021 ◽

Author(s):

L. J. Clarke

Keyword(s):

Irish Sea ◽

Beam Trawl ◽

Morphological Abnormality ◽

Free Swimming ◽

Pectoral Fins ◽

North Wales ◽

Head Section ◽

Thornback Ray ◽

Raja Clavata ◽

The Irish Sea

AbstractA free-swimming thornback ray Raja clavata specimen demonstrating significant morphological abnormality is reported, captured by beam trawl in the Irish Sea off north Wales, UK. The anterior sections of both pectoral fins were separated from the head section for a length of approximately 140 mm extending from the rostrum tip to a point posterior of the spiracles, along with abnormal morphology of the gill slits. This phenomenon has been observed elsewhere but is the first documented example of this abnormality in the eastern Irish Sea, despite widespread targeting of the species across the region by commercial and recreational fishers. Possible causes and consequences of the observed abnormality are discussed.

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Review of the life history, fisheries, and stock assessment for small tunas in the Atlantic Ocean

Reviews in Fish Biology and Fisheries ◽

10.1007/s11160-021-09666-8 ◽

2021 ◽

Author(s):

Flávia Lucena-Frédou ◽

Bruno Mourato ◽

Thierry Frédou ◽

Pedro G. Lino ◽

Rubén Muñoz-Lechuga ◽

...

Keyword(s):

Life History ◽

Atlantic Ocean ◽

Stock Assessment

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The Effect of Azide, Fluoride, Orthovanadate and EDTA Sodium Salts on Ecto-ATPase Activity in Erythrocytes of a Scorpionfish (Scorpaena porcus L.) and Thornback Ray (Raja clavata L.)

Journal of Evolutionary Biochemistry and Physiology ◽

10.1134/s0022093021050033 ◽

2021 ◽

Vol 57 (5) ◽

pp. 1008-1019

Author(s):

Yu. A. Silkin ◽

E. N. Silkina ◽

M. Yu. Silkin

Keyword(s):

Atpase Activity ◽

Sodium Salts ◽

Thornback Ray ◽

Raja Clavata ◽

Scorpaena Porcus

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Effect of NaCl on seed germination in some Centaurium Hill. Species (Gentianaceae)

Archives of Biological Sciences ◽

10.2298/abs0703227z ◽

2007 ◽

Vol 59 (3) ◽

pp. 227-231 ◽

Cited By ~ 3

Author(s):

S. Zivkovic ◽

M. Devic ◽

B. Filipovic ◽

Z. Giba ◽

D. Grubisic

Keyword(s):

Life History ◽

Salt Tolerance ◽

Seed Germination ◽

Gibberellic Acid ◽

White Light ◽

The Other ◽

Distilled Water ◽

Nacl Concentration ◽

History Of ◽

Species Specific

The influence of high NaCl concentrations on seed germination in both light and darkness was examined in the species Centaurium pulchellum, C. erythraea, C. littorale, C. spicatum, and C. tenuiflorum. Salt tolerance was found to depend on the life history of the seeds. To be specific, seeds of all five species failed to complete germination when exposed to continuous white light if kept all the time in the presence of 100-200 mM and greater NaCl concentrations. However, when after two weeks NaCl was rinsed from the seeds and the seeds were left in distilled water under white light for an additional two weeks, all species completed germination to a certain extent. The percent of germination not only depended on NaCl concentration in the prior medium, but was also species specific. Thus, seeds of C. pulchellum, C. erythraea, and C. littorale completed germination well almost irrespective of the salt concentration previously experienced. On the other hand, seeds of C. tenuiflorum completed germination poorly if NaCl concentrations in the prior media were greater than 200 mM. When seeds after washing were transferred to darkness for an additional 14 days, they failed to complete germination if previously imbibed on media containing NaCl concentrations greater than 400 mM. However, the seeds of all species, even if previously imbibed at 800 mM NaCl, could be induced to complete germination in darkness by 1 mM gibberellic acid. .

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