The small pelagic fishery of the Pemba Channel, Tanzania: what we know and what we need to know for management under climate change
- Authors: Sekadende, Baraka , Scott, Lucy E P , Anderson, Jim , Aswani, Shankar , Francis, Julius , Jacobs, Zoe , Jebri, Fatma , Jiddawi, Narriman , Kamukuru, Albogast T , Kelly, Stephen , Kizenga, Hellen , Kuguru, Baraka , Kyewalyanga, Margareth , Noyon, Margaux , Nyandwi, Ntahondi , Painter, Stuart C , Palmer, Matthew , Raitsos, Dionysios , Roberts, Michael J , Sailley, Sévrine F , Samoilys, Melita , Sauer, Warwick H H , Shayo, Salome , Shaghude, Yohana , Taylor, Sarah F W , Wihsgott, Juliane U , Ekaterina Popova
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/178986 , vital:40102 , https://doi.org/10.1016/j.ocecoaman.2020.105322
- Description: Small pelagic fish, including anchovies, sardines and sardinellas, mackerels, capelin, hilsa, sprats and herrings, are distributed widely, from the tropics to the far north Atlantic Ocean and to the southern oceans off Chile and South Africa. They are most abundant in the highly productive major eastern boundary upwelling systems and are characterised by significant natural variations in biomass. Overall, small pelagic fisheries represent about one third of global fish landings although a large proportion of the catch is processed into animal feeds. Nonetheless, in some developing countries in addition to their economic value, small pelagic fisheries also make an important contribution to human diets and the food security of many low-income households. Such is the case for many communities in the Zanzibar Archipelago and on mainland Tanzania in the Western Indian Ocean. Of great concern in this region, as elsewhere, is the potential impact of climate change on marine and coastal ecosystems in general, and on small pelagic fisheries in particular. This paper describes data and information available on Tanzania's small pelagic fisheries, including catch and effort, management protocols and socio-economic significance.
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- Date Issued: 2020
Genetic analysis reveals harvested Lethrinus nebulosus in the Southwest Indian Ocean comprise two cryptic species
- Authors: Healey, Amy J E , Gouws, Gavin , Fennessy, Sean T , Kuguru, Baraka , Sauer, Warwick H H , Shaw, Paul W , McKeown, Niall J
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124538 , vital:35626 , https://doi.10.1093/icesjms/fsx245
- Description: This study initially aimed to investigate the genetic population/stock structuring of Lethrinus nebulosus in the Southwest Indian Ocean (SWIO) to inform management practices in light of emerging evidence of overharvesting of this species throughout its distribution. Adult samples were genotyped for 14 nuclear microsatellites and by sequencing fragments of the mtDNA control region and COI gene. A salient feature of the data was the congruent cyto-nuclear partitioning of samples into two high divergent, reciprocally monophyletic groups. This indicates that despite no a priori evidence, hitherto described L. nebulosus in the SWIO comprises two cryptic species that co-occur among southern samples. This intermingling indicates that, at least in southern samples, both species are being indiscriminately harvested, which may severely compromise sustainability. Limited microsatellite differentiation was detected within both species, though there was some evidence of isolation in the Mauritian population. In contrast, mtDNA revealed a pattern consistent with chaotic genetic patchiness, likely promoted by stochastic recruitment, which may necessitate a spatial bet-hedging approach to management to satisfy fishery management and conservation goals.
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- Date Issued: 2018