Distribution and aspects of Life History of White Hake (Urophycis tenuis
White hake (Urophycis tenuis, Mitchill 1815) is a bottom-dwelling fish distributed only in the northwest Atlantic from Cape Hatteras to southern Labrador; with dense concentrations in the Gulf of Maine, on the Scotian Shelf, in the Gulf of St. Lawrence, and on the southern Grand Banks. Over their en...
| Main Authors: | , , |
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| Format: | Text |
| Language: | English |
| Published: |
2005
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.620.7623 http://archive.nafo.int/open/sc/2005/scr05-060.pdf |
| Summary: | White hake (Urophycis tenuis, Mitchill 1815) is a bottom-dwelling fish distributed only in the northwest Atlantic from Cape Hatteras to southern Labrador; with dense concentrations in the Gulf of Maine, on the Scotian Shelf, in the Gulf of St. Lawrence, and on the southern Grand Banks. Over their entire range, white hakes are found at bottom depths from <50 m to about 800 m. They are mainly associated with 4-8oC ambient temperatures. On the Grand Banks, white hakes are restricted to a narrow band along the southwest edge and into the Laurentian and Hermitage Channels, where bottom temperatures are warmest (>4oC). They occupy a wide range of bottom depths along the slope out to 800 m; at depths considerably greater than what is observed in other parts of their range. White hake may be classified as “ temperature keepers”: maintaining a constant temperature range by changing their depth distribution. The largest year-class since 1977 was observed in 1999; first detected by an IYGPT survey and also observed in a Spanish research survey. An estimated growth rate of about 2.5 cm per month corresponds to the dominant 25-cm mode of white hakes seen in the following year’s Canadian spring research survey. There appears to be some geographic separation of white hake life stages in NAFO Div. 3NO and Subdiv. 3Ps. Spawning occurs in spring (and possibly summer) along the slope of the Grand Bank, and young white hakes settle over the shallow part of the Bank. Juveniles occupy the largest area; including the Laurentian Channel where other life stages rarely |
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