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.

A multifrequency method to classify and evaluate fisheries acoustics data

2006 ◽  
Vol 63 (10) ◽  
pp. 2225-2235 ◽  
Author(s):  
J Michael Jech ◽  
William L Michaels
Keyword(s):  
Clupea Harengus ◽  
Biological Information ◽  
Classification Algorithms ◽  
Atlantic Herring ◽  
Population Abundance ◽  
Acoustic Data ◽  
Video Images ◽  
Abundance Estimates ◽  
Fisheries Acoustics ◽  
Acoustic Surveys

Acoustic surveys have been conducted on Georges Bank from 1998 to present to estimate Atlantic herring (Clupea harengus) population abundance. Acoustic data were collected with a 12 or 18, 38, and 120 kHz Simrad EK500 scientific echo sounder. A pelagic trawl and underwater video images were used to collect biological information and to verify the species composition of acoustic backscatter. A multifrequency classification method was developed to improve the efficiency and accuracy of classifying species from acoustic echograms. In this method, a volume backscatter (Sv) threshold was applied equivalently to all echograms, and then a composite echogram was created based on which frequencies had Sv greater than or less than the Sv threshold. The results of this method were compared with the standard method of visually scrutinizing regions, and metrics were developed to evaluate the accuracy of classification algorithms relative to current methods, as well as to assess the effects of classification methods on population abundance estimates. In general, this method matched visually scrutinized Atlantic herring regions, but with consistent biases in classifying 38 kHz backscatter. The metrics highlighted spatial and temporal changes in the acoustic landscape, which may be indicative of intra- and inter-annual biological changes.

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.

Recurrence of Kills of Atlantic Herring (Clupea harengus harengus) Caused by Dinoflagellate Toxins Transferred Through Herbivorous Zooplankton

1980 ◽  
Vol 37 (12) ◽  
pp. 2262-2265 ◽  
Author(s):  
Alan W. White
Keyword(s):  
Zooplankton Community ◽  
Clupea Harengus ◽  
Bay Of Fundy ◽  
Atlantic Herring ◽  
Red Tides ◽  
Laboratory Studies ◽  
Toxic Dinoflagellate ◽  
General Phenomenon ◽  
Herbivorous Zooplankton ◽  
Clupea Harengus Harengus

Kills of adult herring occurred in two locations in the southwestern Bay of Fundy in July 1979 during a bloom of the toxic dinoflagellate Gonyaulax excavata. Fish showed the same symptoms as in a herring kill linked to G. excavata toxins in 1976. Herring stomachs contained G. excavata toxins (66–245 μg/100 g guts), the cladoceran Evadne nordmanni, and yellow-brown material probably of algal origin. At the time of the kills the zooplankton community was overwhelmingly dominated by E. nordmanni. Furthermore, bioassays showed the presence of G. excavata toxins in the zooplankters (18 μg/g wet plankton). Combined with evidence from the 1976 kill in which pteropods were vectors of the toxins, and with results from recent field and laboratory studies, these new observations and results substantiate that (1) G. excavata toxins can, and do, cause herring kills in nature with planktonic herbivores, E. nordmanni in this case, acting as vectors, and (2) the toxin transfer mechanism is a general phenomenon among herbivorous zooplankton. Similar food chain events may affect finfish in other areas of the world which experience blooms of toxic dinoflagellates.Key words: dinoflagellate toxins, Gonyaulax excavata, herring kills, Clupea harengus harengus, cladoceran, Evadne nordmanni, red tides, zooplankton, fish kills

scholarly journals Inconsistencies in measurement of fish condition: a comparison of four indices of fat reserves for Atlantic herring (Clupea harengus)

2010 ◽  
Vol 68 (1) ◽  
pp. 52-60 ◽  
Author(s):  
Lindsay R. McPherson ◽  
Aril Slotte ◽  
Cecilie Kvamme ◽  
Sonnich Meier ◽  
C. Tara Marshall
Keyword(s):  
Clupea Harengus ◽  
Physiological Status ◽  
Atlantic Herring ◽  
Fish Condition ◽  
Fat Reserves ◽  
Mesenteric Fat ◽  
Morphometric Index ◽  
Biochemical Measurement ◽  
Biochemical Indices ◽  
The Relationship

Abstract McPherson, L. R., Slotte, A., Kvamme, C., Meier, S., and Marshall, C. T. 2011. Inconsistencies in measurement of fish condition: a comparison of four indices of fat reserves for Atlantic herring (Clupea harengus). – ICES Journal of Marine Science, 68: 52–60. Condition is often equated to the magnitude of fat reserves, which can be represented by biochemical, bioenergetic, or morphometric indices. Biochemical indices are technically more demanding, but are direct measures of fat, in contrast to morphometric indices which are easier to measure but are only surrogates of physiological status or condition. This study compared Fulton's K (K), a common morphometric index, with two bioenergetic indices, mesenteric fat and muscle fat content, measured by a commercial fatmeter in Atlantic herring. Fatmeter values and K were also compared with a biochemical measurement of muscle fat. The relationship between K and mesenteric fat was inconsistent and often non-existent. The relationship between K and fatmeter values was stronger for fish with inactive gonads, and the biochemical measure displayed a much stronger correlation with fatmeter values than with K. Studies need explicitly to define condition and ideally validate it against a benchmark, such as a biochemical index.

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.

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