Fecundity and reproductive potential of Scotia-Fundy summer- and autumn-spawning herring (Clupea harengus L.) / G.J. Óskarsson, C.T. Taggart and R.L. Stephenson.: Fs97-6/3182E-PDF
"Total egg production (E) by a fish stock, estimated using fecundity relationships, has been postulated to provide a superior estimate of a stock’s reproductive potential relative to the spawning stock biomass (SSB) estimate. We examined variation in the fecundity of Scotia-Fundy Atlantic herring using ovaries from 100 fully mature individuals collected on German Bank, NW Scotian Shelf, in September 2001 and in relation to historical fecundity estimates. Potential fecundity (FP; number of vitellogenic oocytes in mature ovaries) was a linear function of total length (r2=0.89). Length-specific FP was weakly (r2=0.10) and positively related to Fulton’s body condition index (K) and relative fecundity (eggs per unit somatic weight) was a positive linear function of total length (r2=0.61). The length-specific fecundity estimates in 2001 were higher than estimates recorded during the late 1960s and mid 1970s and the difference is not adequately explained by K or other factors. Decreases in length-at-age, age- and length-at-maturity and total egg production, particularly contributions from the larger (older) spawners, were observed over the period 1970-2001 and are consistent with changes that could be induced through size-selective fishing practices that target larger (faster growing and late maturing) individuals. The relationship between annual estimates of E and SSB for the stock over the same period approached proportionality with both recruit and repeat spawners indicating that reproductive potential may be adequately estimated from SSB. Partitioning the reproductive potential between recruit and repeat spawners or among different age or length classes may prove to be essential when determining the recruitment potential of the stock"--Abstract, p. v.
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| Department/Agency | Canada. Department of Fisheries and Oceans. |
|---|---|
| Title | Fecundity and reproductive potential of Scotia-Fundy summer- and autumn-spawning herring (Clupea harengus L.) / G.J. Óskarsson, C.T. Taggart and R.L. Stephenson. |
| Variant title | Title at head of French abstract: Fécondité et potentiel reproducteur des fraies d'été et d'automne du hareng (Clupea harengus L.) |
| Series title | Canadian technical report of fisheries and aquatic sciences, 1488-5379 ; 3182 |
| Publication type | Series - View Master Record |
| Language | [English] |
| Format | Electronic |
| Electronic document | |
| Note(s) | Cover title. Includes bibliographical references (p. 11-14). Includes abstract in French. |
| Publishing information | [Ottawa] : Fisheries and Oceans Canada, c2016. |
| Author / Contributor | Óskarsson, G. J.(Guðmundur Jóhann),1978- Taggart, Christopher Thomas,1951- Stephenson, Robert (Robert L.) |
| Description | vii, 27 p. : ill., maps |
| ISBN | 978-0-660-06591-5 |
| Catalogue number |
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| Subject terms | Fisheries resources Salt water fish Fishing area Fisheries management |
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