NatMIRCDept of the Ministry of Fisheries and Marine Resourceshttp://hdl.handle.net/1834/10122024-03-28T14:34:16Z2024-03-28T14:34:16ZRebuilding the Namibian hake fishery: a case for collaboration between scientists and fishermenPaterson, BarbaraKainge, Paulushttp://hdl.handle.net/1834/148092021-05-19T06:18:11Z2014-01-01T00:00:00ZRebuilding the Namibian hake fishery: a case for collaboration between scientists and fishermen
Paterson, Barbara; Kainge, Paulus
One of the most important fisheries in the northern Benguela is the Namibian hake fishery, which targets both Merluccius capensis and Merluccius paradoxus. In spite of attempts to rebuild the hake stocks that were severely depleted by distant-water fleets before Namibia's independence in 1990, stocks have failed to recover. Because the ecological goal of stock rebuilding competes with social and economic objectives on the political stage, the ability to make accurate abundance estimates is important. However, the precision of abundance estimates is impeded by lack of understanding of hake behavior and of the effects of environmental factors. Furthermore, at present both species of hake are assessed and managed as one Namibian stock. We present qualitative information derived from interviews that we conducted with Namibian hake trawl and longline fishers during the 2009 and 2010 fishing seasons, and information gleaned from analyzing logbook data. We contextualize both types of data within the scientific literature on Namibian hakes and the Namibian hake fishery. Fishers monitor sea surface and bottom temperature, water quality, currents, and weather, and they have detailed knowledge about the behavior and habitat of hakes. Fishers differentiate between three different types of M. capensis, which they associate with different fishing areas. They also describe innovations that have taken place over the past 20 years, which are of relevance to the assessment of fishing efficiency and effort, but have not been taken into account in the stock assessments. Our analysis of logbook data supports the increase in efficiency. The results show that closer collaboration between scientists and fishers has the potential to improve the accuracy of survey estimates and stock assessments, and thus is important for rebuilding of hake stocks and the hake fishery.
2014-01-01T00:00:00ZThe community structure of demersal fish species from bottom-trawls off Namibia and the West coast of South Africa.Mwafila, Samuel Kakambihttp://hdl.handle.net/1834/147912021-05-19T06:18:12Z2017-01-01T00:00:00ZThe community structure of demersal fish species from bottom-trawls off Namibia and the West coast of South Africa.
Mwafila, Samuel Kakambi
Changes in the structure and composition of the demersal fish assemblages are assessed using a variety of ecosystem indicators known to capture such changes, which may be induced by bottom-trawling. The aim of this study was to investigate whether there are any structural changes in demersal fish assemblages by way of latitudinal variation. The study was conducted from the Kunene River to Agulhas Bank during the 2007 demersal surveys. Abundance and biomass data was analysed using cluster analysis, non-metric multidimensional scaling, abundance biomass comparison curves, and similarity profiles in PRIMER v6 software. The dendrogram identified three main groups, two in northern Benguela, separated into shelf and slope assemblages and one in the southern Benguela, without any distinction between shelf and slope at 19% similarity. Identified assemblages are spatially distinct. The average similarities on the continental shelf in northern Benguela were driven by the following top three species: M. capensis, Sufflogobius bibarbatus and Trachurus trachurus capensis; on the continental slope they were driven by M. paradoxus, Nezumia micronychodon and Helicolenus dactylopterus; while the similarities in southern Benguela assemblages were driven by M. paradoxus, H. dactylopterus and Lophius vomerinus, in order of % contribution.
2017-01-01T00:00:00ZEvaluation of the Status of the Namibian Hake Resource (Merluccius spp.) Using Statistical Catch-at-Age Analysis.Kirchner, CarolaKainge, PaulKathena, Johanneshttp://hdl.handle.net/1834/147902021-05-19T06:18:12Z2012-01-01T00:00:00ZEvaluation of the Status of the Namibian Hake Resource (Merluccius spp.) Using Statistical Catch-at-Age Analysis.
Kirchner, Carola; Kainge, Paul; Kathena, Johannes
Namibian hake is the most important fish resource in Namibia. This monograph is a compilation of all the hake data, historic and recent, that has been used to inform stock assessment and management since the late 1970s. It presents the statistical catch-at-age analysis used to evaluate the state of the Namibian hake resource under different assumptions. This analysis treats the two hakes, Merluccius paradoxus and M. capensis, as a single stock. The data and modeling show that the stock has not as yet recovered to its maximum sustainable yield level, despite foreign fishing effort having been removed in 1990. Best estimates suggest the current stock to be roughly 20% of pre-exploitation levels; however this figure is sensitive to model assumptions. Signs indicate that the stock is slowly recovering from its all-time low in 2002-2004. Because the two hake species are pooled for assessment, the resource is currently managed on a relatively simple adaptive basis; 80% of the estimated replacement yield is reserved for fishing, the remainder being left for rebuilding.
2012-01-01T00:00:00ZCharacterizing and Comparing the Spawning Habitats of Sardine (Sardinops sagax) and Anchovy (Engraulis encrasicolus) in the Northern Benguela RegionTjizoo,Mbeurora Beauhttp://hdl.handle.net/1834/52312021-05-19T06:18:11Z2008-01-01T00:00:00ZCharacterizing and Comparing the Spawning Habitats of Sardine (Sardinops sagax) and Anchovy (Engraulis encrasicolus) in the Northern Benguela Region
Tjizoo,Mbeurora Beau
Spawning habitats of sardine and anchovy in eastern boundary current systems are characterized in an attempt to understand the fluctuations observed in their abundance. The northern Benguela, as an eastern boundary current system, is characterized by turbulent conditions that seem to govern the variability observed in the abundance of these species. Sardine and anchovy have developed mechanisms that enable them to maximize productivity. In the northern Benguela, spawning intensity is historically known to be high in periods and vicinities where turbulence is reduced. However, it is believed that selection of conditions for spawning by these species may change withfluctuations in abundance of fish.
2008-01-01T00:00:00Z