Variation in maturity-at-age and size in three populations of American plaice

Morgan, M. J.; Colbourne, Eugene

doi:10.1006/jmsc.1999.0487

Cited by 90 publications

(83 citation statements)

References 34 publications

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“…For example, age at maturity of cod from the Irish Sea diminished when SSB decreased, although growth rates did not change (Armstrong et al, 2004). In similar way, size and age at maturity of American plaice from Northwest Atlantic has decreased since the 1960s coinciding also with a decrease of SSB, the maturation of cohorts being related to total abundance of the stock over the whole life history of the cohort (Morgan and Colbourne, 1999). However, Rätz and Lloret (2005) suggest that for Greenland cod population density only affects growth of younger age groups.…”

Section: Changes In Maturity Ogives In Response To Environmental Flucmentioning

confidence: 88%

Changes in size at maturity of European hake Atlantic populations in relation with stock structure and environmental regimes

Domínguez-Petit

Korta

Saborido-Rey

et al. 2008

Journal of Marine Systems

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European hake (Merluccius merluccius) female size at maturity is estimated on an annual basis for Bay of Biscay and Galician coast, which are parts of the distribution of the Northern and Southern stocks, respectively. Clear trends in this reproductive parameter are observed along the time series and the potential factors affecting these trends have been investigated. Total biomass, different indexes of SSB, age diversity index, fishing mortality at age, NAO winter index, upwelling index and temperature were included in multiple regressions models to assess the relative importance of each of them on shifts in size at maturity.

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Section: Changes In Maturity Ogives In Response To Environmental Flucmentioning

confidence: 88%

Changes in size at maturity of European hake Atlantic populations in relation with stock structure and environmental regimes

Domínguez-Petit

Korta

Saborido-Rey

et al. 2008

Journal of Marine Systems

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“…This cohort‐based approach generally follows that of Morgan and Colbourne (1999). All data manipulation and data analyses were performed in SAS/STAT software version 9.3 (SAS Institute Inc. 2011).…”

Section: Methodsmentioning

confidence: 99%

Size‐selective fishing and the potential for fisheries‐induced evolution in lake whitefish

Morbey

Mema

2018

Evolutionary Applications

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The long‐term evolutionary effects of fishing on maturation schedules can depend on gear type, the shape of the gear type's size‐selectivity function, and the size and age structure of a population. Our goal was to better understand how environmentally induced differences in somatic growth influence the evolutionary effects of size‐selective fisheries, using lake whitefish (Coregonus clupeaformis) in Lake Huron as a case study. Using a state‐dependent optimization model of energy allocation parameterized for lake whitefish, we show that fishing with gill nets (bell‐shaped selectivity) and trap nets (sigmoid‐shaped selectivity) can be potent agents of selection on size thresholds for maturity. Compared to trap nets and large mesh (114 mm) gill nets, small mesh (89 mm) gill nets are better able to buffer populations from fishing‐induced evolution by safeguarding large, fecund fish, but only when overall fishing mortality is low and growth rates sufficiently fast such that fish can outgrow vulnerable size classes. Regardless of gear type, and all else being equal, high fishing mortality in combination with low growth rates is expected to intensify the long‐term evolutionary effects of fishing.

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“…For most gadoids and flatfish stocks, substantial temporal variation in maturity ogives has been reported, which reflect density-dependent growth changes related to fishery exploitation and environmental influences (e.g. Templeman et al, 1978;Bowering and Brodie, 1991;Morgan and Colbourne, 1999;OBrien, 1999;Saborido-Rey and Junquera, 1999). Consequently, whenever possible, time series using annual or temporally discrete maturity ogives should replace knife-edge or constant maturity ogives.…”

Section: Discussionmentioning

confidence: 99%

“…If the proportion mature is defined as a plus group (assuming knife-edge maturity) or constant maturity ogives are used to calculate SSB, revised SSB estimates that simply account for natural variability in maturation may constitute a significant improvement (Morgan, MS 2000;Köster et al, 2003;Marshall et al, 2003). Growth, maturation and mortality are often sexually dimorphic in marine fish species with males maturing at smaller sizes and younger ages than females, and female longevity exceeding that of males (O'Brien et al, 1993;Atkinson, 1995;Trippel et al, 1997;Morgan and Colbourne, 1999). Consequently, the sex ratio in the SSB varies depending on the age/ size composition of the spawning stock, which compromises the reliability of SSB as an index of SRP (Jakobsen and Ajiad, 1999;Kraus et al, 2002).…”

Section: Introductionmentioning

confidence: 99%

Available Information for Estimating Reproductive Potential of Northwest Atlantic Groundfish Stocks

Tomkiewicz¹,

Morgan²,

Burnett³

et al. 2003

J. Northw. Atl. Fish. Sci.

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The availability of data to improve indices of stock reproductive potential was reviewed for 42 Northwest Atlantic groundfish stocks comprising gadoids, flatfishes, redfishes and grenadiers. For many of the stocks, information on population parameters such as stock size and size/age composition estimates exists for three or more decades. Data on fish age, weight, maturity and sex ratios in the population have also been extensively collected, often allowing for establishment of time series of annual data that could be used for assessing spawning stock biomass and female spawning stock. However, possibilities for estimating stock potential egg production are constrained by scarcity of fecundity data. Data on fish condition, which can be useful in developing fecundity models, were seldom collected in earlier times, but have increased in recent decades. A data richness index, combining information about data quantity and quality, ranked most gadoid stocks as "data comprehensive" with a high proportion of stocks possessing some fecundity information. Flatfish stocks generally were "data moderate" owing to slightly shorter time series of data, while redfish and grenadier stocks in general were "data restricted". Published studies linking aspects of reproductive potential with parental characteristics and/or recruitment have become more frequent as "data richness" has improved for many stocks, but generally the prevalence of such studies remains low.

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Variation in maturity-at-age and size in three populations of American plaice

Cited by 90 publications

References 34 publications

Changes in size at maturity of European hake Atlantic populations in relation with stock structure and environmental regimes

Changes in size at maturity of European hake Atlantic populations in relation with stock structure and environmental regimes

Size‐selective fishing and the potential for fisheries‐induced evolution in lake whitefish

Available Information for Estimating Reproductive Potential of Northwest Atlantic Groundfish Stocks

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