Discreteness of Atlantic Herring (Clupea harengus harengus) Populations in Spring and Autumn Fisheries in the Southern Gulf of St. Lawrence

1971 ◽  
Vol 28 (7) ◽  
pp. 1009-1014 ◽  
Author(s):  
S. N. Messieh ◽  
S. N. Tibbo
Keyword(s):  
Growth Rate ◽  
Clupea Harengus ◽  
Atlantic Herring ◽  
Frequency Distributions ◽  
Dorsal Fin ◽  
Class Composition ◽  
Fin Rays ◽  
Spawning Time ◽  
Clupea Harengus Harengus

Evidence was obtained that spring and autumn herring fisheries in the southern Gulf of St. Lawrence are supported by two discrete stocks. Samples from the two fisheries taken in 1965 through 1969 differed in length- and age-frequency distributions, year-class composition, growth rate, spawning time, and mean numbers of pectoral and dorsal fin rays.

Meristic Differences between Spring- and Autumn-Spawning Atlantic Herring (Clupea harengus harengus) from Southwestern Newfoundland

1971 ◽  
Vol 28 (4) ◽  
pp. 553-558 ◽  
Author(s):  
L. S. Parsons ◽  
V. M. Hodder
Keyword(s):  
Clupea Harengus ◽  
Atlantic Herring ◽  
Gill Rakers ◽  
Dorsal Fin ◽  
Fin Ray ◽  
Significant Difference ◽  
Fin Rays ◽  
Developmental Rates ◽  
Clupea Harengus Harengus ◽  
Gill Raker

Numbers of vertebrae, gill rakers, and of pectoral, anal, and dorsal fin rays of spring- and autumn-spawning Atlantic herring (Clupea harengus harengus Linnaeus) in 10 samples from the coastal waters of southwestern Newfoundland were compared. There was no significant difference (P > 0.05) between mean vertebral numbers of spring and autumn spawners. Mean numbers of gill rakers and of pectoral, anal, and dorsal fin rays were all higher (P < 0.01) for autumn spawners than for spring spawners with gill-raker and pectoral fin-ray numbers exhibiting the greatest degree of difference. It is suggested that the differences in fin-ray numbers between spring and autumn spawners are related to water temperatures during larval development and to differences in developmental rates of spring- and autumn-hatched larvae.

Recruitment: a Problem of Multispecies Interaction and Environmental Perturbations, with Special Reference to Gulf of St. Lawrence Atlantic Herring (Clupea harengus harengus)

1976 ◽  
Vol 33 (6) ◽  
pp. 1353-1371 ◽  
Author(s):  
P. F. Lett ◽  
A. C. Kohler
Keyword(s):  
Growth Rate ◽  
Structural Equation ◽  
Clupea Harengus ◽  
Fine Tuning ◽  
Management Tool ◽  
Larval Abundance ◽  
Food Density ◽  
Atlantic Herring ◽  
Age Group ◽  
Clupea Harengus Harengus

A stochastic model was developed to study effects of temperature perturbations, predation, and competition from Atlantic mackerel (Scomber scombrus) on the recruitment process for Gulf of St. Lawrence Atlantic herring (Clupea harengus harengus). Multivariate statistics were used to determine the structural equation for portions of the life history of herring. Temperature and the abundance of age-group 0 mackerel affected the herring growth rate, but neither total herring biomass nor total pelagic biomass had any measurable effect on herring growth rate. Herring growth rate, coupled with adult stock size and environmental effects, mediated through temperature were the prime determinants of larval abundance less than 10 mm. Density-dependent growth was found in the l1 stage but is argued as being anomalous in relation to age-group 0 herring maximizing their production to simultaneously stabilize both l1, (the 1st yr of life) and year-class size. Predation, tempered by available food density, is discussed as a major population stabilizing and a fine-tuning mechanism for year-class formation. The ramifications of variation in recruitment are discussed in relation to the Beverton and Holt and the Schaefer models. In addition, the Ricker recruitment curve is confirmed as being a viable fisheries management tool.

Delineating Spring and Autumn Herring Populations in the Southern Gulf of St. Lawrence by Discriminant Function Analysis

1975 ◽  
Vol 32 (4) ◽  
pp. 471-477 ◽  
Author(s):  
S. N. Messieh
Keyword(s):  
Discriminant Function ◽  
Discriminant Function Analysis ◽  
Function Analysis ◽  
Clupea Harengus ◽  
Maturation Stage ◽  
Atlantic Herring ◽  
General Applicability ◽  
Dorsal Fin ◽  
Maturation Stages ◽  
Clupea Harengus Harengus

A discriminant function based on three variables, pectoral and dorsal fin rays and gill rakers, was calculated for Atlantic herring (Clupea harengus harengus) taken from spring- and autumn-spawning concentrations in the southern Gulf of St. Lawrence and tested for general applicability by classifying other herring of known origin. The function was then used to classify herring sampled from feeding concentrations. Results showed that feeding herring (pre- and postspawning) comprised a mixture of spring and autumn herring populations averaging 51.8 and 48.2%, respectively.The observed heterogeneity of feeding concentrations, in contrast to homogeneity of spawning concentrations, confirmed the hypothesis that spring and autumn herring populations mix during feeding, though they separate at the onset of spawning. Discriminant function analysis is most useful for separating herring spawning groups during their feeding season when overlap of maturation stages prevents separation by maturation stage alone.

Interaction Between Stock Area, Stock Abundance, and Catchability Coefficient

1985 ◽  
Vol 42 (5) ◽  
pp. 989-998 ◽  
Author(s):  
G. H. Winters ◽  
J. P. Wheeler
Keyword(s):  
Stock Assessment ◽  
Population Decline ◽  
Clupea Harengus ◽  
Atlantic Herring ◽  
Population Abundance ◽  
Commercial Catch ◽  
Standard Manner ◽  
Clupea Harengus Harengus ◽  
The Relationship ◽  
Stock Abundance

The relationship between commercial catch-rates and population density upon which many stock assessment models depend assumes that stock area (A) is constant and independent of population abundance. Starting from a theoretical demonstration that the catchability coefficient (q) is inversely proportional to A, we establish the empirical basis of this relationship through comparisons of q and A of various Northwest Atlantic herring (Clupea harengus harengus) stocks and, in more detail, for Fortune Bay herring. For these stocks the relationship was of the form q = cA−b. For Atlantic herring stocks, levels of b were in excess of 0.80. In Fortune Bay herring, reductions in abundance were accompanied by proportional reductions in A, which in turn was inversely correlated with changes in q. School size, measured as catch per set, also declined as population levels declined but the change was not proportional. Published findings indicate that pelagic stocks in particular, and fish stocks in general, exhibit a common response of reductions in A with interactive increases in the q during periods of rapid population decline. We conclude that the conventional assumption of a constant stock area is usually violated due to the systematic interaction between A and population abundance which is reflected in an inverse relationship between stock abundance and q. Calibration of sequential population models should therefore be restricted to research vessel data collected in a standard manner and covering the distributional area of the stock.

Ultrastructural Studies of Piscine Erythrocytic Necrosis (PEN) in Atlantic Herring (Clupea harengus harengus)

1978 ◽  
Vol 35 (1) ◽  
pp. 148-154 ◽  
Author(s):  
Paul W. Reno ◽  
Marie Philippon-Fried ◽  
Bruce L. Nicholson ◽  
Stuart W. Sherburne
Keyword(s):  
Electron Microscope ◽  
Key Words ◽  
Clupea Harengus ◽  
Type I ◽  
Atlantic Herring ◽  
Type Ii ◽  
Inclusion Type ◽  
Cytoplasmic Inclusions ◽  
Ultrastructural Studies ◽  
Clupea Harengus Harengus

Erythrocytes of PEN-positive Atlantic herring (Clupea harengus harengus) were examined to determine their ultrastructure. Cytoplasmic inclusions were of two types when observed under the electron microscope. The first type (type I) appeared coarsely granular, electron dense, round, and up to 1.5 μm in diameter. Virions were closely associated with this type of inclusion. The second type of inclusion (type II) had approximately the same appearance as the surrounding cytoplasm, from which it was separated by a discrete membrane, and was variable in size. Virions were not intimately associated with type II inclusions. Virions occurred singly or in clusters within the cytoplasm or in association with type I inclusions and were hexagonal and 145 nm in diameter. Virions were composed of a rigid hexagonal capsid 8 nm wide, a lighter 16-nm region, and a core 100 nm in diameter. The virus of PEN is presumptively classified as an Iridovirus. Key words: ultrastructure, erythrocytes, virology

Direct and Indirect Estimation of Gillnet Selection Curves of Atlantic Herring (Clupea harengus harengus)

1990 ◽  
Vol 47 (3) ◽  
pp. 460-470 ◽  
Author(s):  
G. H. Winters ◽  
J. P. Wheeler
Keyword(s):  
Selection Criterion ◽  
Mesh Size ◽  
Clupea Harengus ◽  
Atlantic Herring ◽  
Population Parameters ◽  
Composition Data ◽  
Catch Data ◽  
Specific Selectivity ◽  
Acoustic Surveys ◽  
Clupea Harengus Harengus

Length-specific selection curves for Atlantic herring (Clupea harengus) were calculated for a series of gillnets ranging in mesh size from 50.8 to 76.2 mm (stretched measure) using Holt's (1963) model (ICNAF Spec. Publ. 5: 106–115). These curves were than compared with direct estimates of length-specific selectivity obtained from a comparison of gillnet catch length frequencies with population length composition data as determined from acoustic surveys. Selection curves calculated indirectly using the Holt model were unimodal and congruent. The empirical selection curves however were multimodal and fishing power varied with mesh size. These differences in selectivities were due to the fact that herring were caught not only by wedging at the maximum girth but also at other body positions such as the gills and snout. Each of these modes of capture have different length-specific selectivity characteristics and, since the relative contributions of the different modes of capture varied both between nets and annually, the selection curve of herring for a particular mesh size is not unique. It can however be reasonably approximated when girth is used as the selection criterion. Direct empirical selectivities are therefore recommended when interpreting population parameters from herring gillnet catch data.

Potential of Eimeria sardinae (Apicomplexa: Eimeridae) Oocysts for Distinguishing between Spawning Groups and between First- and Repeat-Spawning Atlantic Herring (Clupea harengus harengus)

1987 ◽  
Vol 44 (7) ◽  
pp. 1379-1385 ◽  
Author(s):  
Sharon E. McGladdery
Keyword(s):  
Clupea Harengus ◽  
Maturity Stage ◽  
Atlantic Herring ◽  
Spawning Grounds ◽  
The Difference ◽  
Mature Fish ◽  
Clupea Harengus Harengus ◽  
Surrounding Areas ◽  
Immature Fish ◽  
Northeastern Atlantic

Prevalence of Eimeria sardinae oocysts was closely correlated with the maturity stage of the testes of Atlantic herring (Clupea harengus harengus). Prevalence was low in testes of immature fish, increased in ripe and spawning fish, and decreased in postspawning fish. No correlation was found between prevalence and age of spawning herring. The uniformly high prevalences in mature fish indicated the efficiency of transmission on the spawning grounds, where infective oocysts are released. Infection of first-spawning herring (approximately age 3) indicated that the oocysts may be dispersed to surrounding areas or immature fish may associate with spawning aggregations. Therefore, this parasite could not be used to distinguish first from repeat spawners. Prevalence oF E. sardinae peaked in May and September, and possibly in June and early July, thereby distinguishing two, and possibly three, spawning groups. A previous study indicated no correlation between maturity stage and infections by E. sardinae in northeastern Atlantic herring. The difference between the two sides of the Atlantic is attributed to greater mixing of immature and adult herring around spawning grounds and/or greater dispersal of infective oocysts from spawning grounds in the northeastern Atlantic, compared with those in the northwest.

Isolation and characterization of antifreeze proteins from smelt (Osmerus mordax) and Atlantic herring (Clupea harengus harengus)

1990 ◽  
Vol 68 (8) ◽  
pp. 1652-1658 ◽  
Author(s):  
K. Vanya Ewart ◽  
Garth L. Fletcher
Keyword(s):  
Antifreeze Proteins ◽  
Gel Filtration ◽  
Exchange Chromatography ◽  
Clupea Harengus ◽  
Osmerus Mordax ◽  
Atlantic Herring ◽  
Activity Levels ◽  
Isolation And Characterization ◽  
Sea Raven ◽  
Clupea Harengus Harengus

Antifreeze proteins (AFPs) from smelt (Osmerus mordax) and Atlantic herring (Clupea harengus harengus) were isolated using gel filtration, ion exchange chromatography, and high performance liquid chromatography. The AFPs of smelt appeared to consist of at least six components and those of Atlantic herring, of at least two components. The relative molecular masses of these antifreezes were 24 000 and 14 600, respectively. Amino acid analysis showed both proteins to be cystine-rich, type II AFPs like those of the sea raven (Hemitripterus americanus). In addition, smelt AFPs were found to be immunologically similar to those of the sea raven. The smelt AFPs differed from those of Atlantic herring and sea raven in that they contained a small amount of glucosamine (~3%). The activity levels of the smelt and herring AFPs were reduced in the presence of dithiothreitol, indicating the functional importance of intact disulfide bonds.

Maturation and Spawning of Atlantic Herring (Clupea harengus harengus) in the Southern Gulf of St. Lawrence

1975 ◽  
Vol 32 (1) ◽  
pp. 66-68 ◽  
Author(s):  
S. N. Messieh
Keyword(s):  
Clupea Harengus ◽  
Atlantic Herring ◽  
Spawning Grounds ◽  
Nursery Areas ◽  
Maturity Stages ◽  
Clupea Harengus Harengus

Analysis of maturity stages of herring samples taken from the southern Gulf of St. Lawrence shows two maturation cycles for spring and autumn spawning herring. The spring population has a spawning peak in May and the summer–autumn population extends spawning from July through September. Spawning grounds of spring and autumn herring populations and their nursery areas are mapped.

Timing of Spawning of Atlantic Herring (Clupea harengus harengus) Populations and the Match–Mismatch Theory

1984 ◽  
Vol 41 (7) ◽  
pp. 1055-1065 ◽  
Author(s):  
M. Sinclair ◽  
M. J. Tremblay
Keyword(s):  
Larval Growth ◽  
Clupea Harengus ◽  
Atlantic Herring ◽  
Juvenile Form ◽  
Larval Phase ◽  
Spawning Period ◽  
Larval Retention ◽  
Clupea Harengus Harengus ◽  
Mismatch Theory ◽  
Timing Of Spawning

Each population of Atlantic herring (Clupea harengus harengus) has its own seasonally fixed spawning period of a few weeks duration, but the mean spawning times of different populations differ substantially. The extant theory explains the population-specific timing of spawning relative to the plankton production blooms in the inferred larval distributional area. Support of this theory is evaluated, and found lacking, in the light of a recent "stock" hypothesis involving larval retention. The new hypothesis involves two constraints. First, the larvae of a discrete herring population develop within, and are thus adapted to, the specific oceanographic conditions of their larval retention area. Second, metamorphosis from the larval to juvenile form occurs primarily within a restricted period of the year (April to October). Given these two constraints, it is hypothesized that the timing of spawning of a herring population is a function of the time necessary to complete the larval phase and yet metamorphose within the acceptable seasonal envelope. Populations that have "good" larval retention areas can spawn in the spring and still metamorphose within the seasonal envelope. Populations with larval retention areas that are less "good" for larval growth have to spawn earlier to satisfy the two constraints. The implications of the hypothesis on the "match–mismatch" theory are briefly discussed.

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