Journal
FISHERIES OCEANOGRAPHY
Volume 24, Issue -, Pages 31-45Publisher
WILEY-BLACKWELL
DOI: 10.1111/fog.12058
Keywords
hatch date distribution; horizontal distribution; migration; northern Benguela; shallow-water hake; spawning areas; spawning period; vertical distribution
Categories
Funding
- SEAChange Project of the South African Network for Coastal and Oceanic Research - Branch: Marine and Coastal Management
- National Research Foundation
- South African Research Chairs Initiative of the Department of Science and Technology
- National Research Foundation, through the Research Chair in Marine Ecology and Fisheries
Ask authors/readers for more resources
We investigate the spatial distributions of juvenile and adult hake Merlucciuscapensis on the Namibian continental shelf using data from 25 biomass surveys (1990-2007) to identify (i) nursery/spawning areas, their spatial or temporal separation and change and (ii) length, depth and latitude preference patterns. The density of fish (number-of-fish per30-min-haul) was examined in relation to fish total length (TL) and latitude and TL and bottom depth. Nursery aggregations were most frequent in central (22-25 degrees S) and southern (26-29 degrees S) Namibia, increasing in density in the south since 2000. Hatch dates of 17cm fish were calculated from juvenile growth rates. Peaks occurred in winter and summer-autumn in the centre and slightly later in the south. Spawning areas appear to have shifted southward since the late 1970s, showing the plasticity of this stock as a response to fishing pressure and environmental variability and change. Merlucciuscapensis show a stable pattern of latitude preference over the 25 surveys examined. They first occur on the mid-shelf <9cm, generally moving to the inner-shelf at 9-15cm (<1yr old). They generally prefer the northern and mid-shelf area between 24 and 45cm (1.5-3.5yr old), probably for feeding and building resources for spawning purposes. They later move to the outer-shelf and return southward and to the mid-shelf region to spawn at 45cm TL (3.5years old), a contained stock unit in the northern Benguela. We propose a complete migration life history of M.capensis for the first time, showing their extensive longitudinal migrations, similar to Merluccius species elsewhere.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available