LAKE VICTORIA AND THE COMMON PROPERTY DEBATE: IS THE TRAGEDY OF THE COMMONS A THREAT TO ITS FUTURE?

Lake Victoria is the largest among the African Great Lakes in East African region that are believed to have both dynamic and fragile aquatic ecosystems. Within two decades, the lake has experienced extensive resource exploitation leading to constrained productivity and drastic decline of native biodiversity. Intensive non-selective fishing, catchment vegetation degradation, industrial and agricultural pollution, the introduction of exotic species and uneven patchwork of governmental laws are some of the reasons for the current ecological woes facing Lake Victoria. This paper intends to stimulate recognition of Lake Victoria and its catchment as a lived Com­mons, to be shared, protected, managed and enjoyed by all who live around it. The paper compares the original biodiversity status of the lake with the current status and discusses the role of unlimited access as a function of the loss of the Lake’s biological wealth. The Lake’s water resource base, fishery, wetlands and other aquatic resources have been exhaustively discussed. In this review, we uphold the Hardin’s school of thought that freedom of the commoners causes resource overuse leading to poverty. Therefore, limiting freedom could be essential. However, there is need for provision of alternative means of survival since people with no choices would continue over-exploiting ecosystems even under limited access. The Lake Victoria basin commons should be protected by strict legal and clear political frame­work based on public trust doctrine, reinforced in law that the Lake is vital for the survival of people, plants and animals living on or near it and therefore must be protected for the common good. The political jurisdictions should consider governing the Lake basin as one integrated watershed. It is our fervent hope that bordering communities will secure grass root movements to protect and nurture Lake Victoria and its environs for the benefit of the present and future generations

Genetic differentiation of Artemia franciscana (Kellogg, 1906) in Kenyan coastal saltworks

The nature of genetic divergence between the Artemia population native to San Francisco Bay, (SFB) USA and those from the introductions of SFB material in the Kenyan coast two decades ago were investigated using the mitochondrial DNA (mtDNA) and heat shock protein 70 (Hsp70) gene molecular markers. The DNA was extracted from 80 single Artemia cysts using the Chelex protocol. The 1,500 bp fragment of the 12S - 16S region of the mtDNA and a 1,935 bp fragment of the Hsp70 gene were amplified through Polymerase Chain Reaction (PCR) followed by Restriction Fragment Length Polymorphism (RFLP) digestion using appropriate endonucleases. The mtDNA analysis indicated higher haplotype diversity (0.76 ± 0.07) in Artemia from Fundisha saltworks while the rest of the samples were monomorphic. A private haplotype (AAABBA) in Fundisha samples confirmed a molecular evidence of a systematic genetic differentiation albeit in an insignificant manner (P > 0.05). There was molecular evidence of coexistence of SFB and GSL Artemia strains in Fundisha saltworks. The monomorphic DNA fingerprint in Kensalt Artemia cysts was probably caused by non-sequential Artemia culture system and limited mtDNA fragment size analysed. The Hsp70 gene RFLP fingerprint did not show any unique gene signatures in the Kenyan Artemia samples suggesting that other factors other than Hsp70 were involved in their superior thermotolerance. Further genetical studies based on the larger mtDNA fragment using robust genetic markers are recommended. Ecological studies of the heat shock protein family and the stress response would be more relevant than the qualitative RFLP technique

Phytoplankton distribution along a salinity gradient in two Kenyan saltworks (Tana and Kurawa)

The current study assessed the diversity and abundance of phytoplankton genera in two Kenyan saltworks (Tana and Kurawa) in March and September 2021. Water samples were obtained from ponds with salinities ranging from 30 to 200 ppt by filtering 40 l of water using a 20-μm phytoplankton net. Seventy-six genera of phytoplankton were identified. Genera richness, evenness and diversity decreased with increasing salinity while phytoplankton abundance increased with increasing salinity. Higher phytoplankton densities were observed in the Tana than in the Kurawa saltworks. Ponds of <100 ppt were dominated by Dinophyceae and Bacillariophyceae which accounted for >90 % of the phytoplankton community. Ponds of salinities >100 ppt were dominated by Cyanophyceae which accounted for >90 % of the phytoplankton community. From the results it was concluded that Kenyan saltworks host diverse phytoplankton genera whose richness decreases with increasing salinity and varies with seasons. The present data describes variation of phytoplankton assemblages in salt ponds between two selected seasons, but several samplings throughout the year would be more appropriate to describe variations of phytoplankton with season in these salt ponds

Seasonal Changes of Length -Weight Relationship and Condition Factor of Five Fish Species in Lake Baringo, Kenya

This study describes the length-weight relationships (LWR) and relative condition factor (K) of five fish species in Lake Baringo, Kenya. A total of 483 fishes consisting of Barbus intermedius, Clarias gariepinus, Labeo cylindricus, Oreochromis niloticus baringoensis and Protopterus aethiopicus were collected on monthly basis from Lake Baringo between September 2012 and August 2013. There was a significant difference (P < 0.05) in the weight at unit length (b) of the length weight relationship between the wet and dry season in all the fish species. However, there was no significant difference (P> 0.05) in condition factor between the two seasons. In all the five species studied, the sex ratio did not deviate from the expected sex ration of 1:1. The b values were within the range of 2.2 and 3.4 in both the dry and the wet seasons respectively, indicating an isometric growth of the fishes. The condition factor (K) for all the five species from Lake Baringo was well above 1 suggesting a relatively good physiological condition of the fishes in the lake. The seasonal variation influenced the length-weight relationship of the fishes but did not affect the condition factor and the sex ratio of all the fish species in Lake Baringo. The authors recommend a further study taking into account the fluctuations of water quality parameters

The challenges of management: Recent experiences in implementing fisheries co‐management in Lake Victoria, Kenya

This study examined the efficacy of community‐level fishery co‐management organizations called Beach Management Units (BMUs) along the Kenyan shores of Lake Victoria. BMUs were established to enhance sustainable Lake Victoria fishery management through increasing the level of community participation to assist in the administration of fisheries rules and regulations by, and for, the fishers. Inefficiencies have emerged, however, inhibiting the effective execution of sustainable fisheries management by the BMUs. Data were collected from 36 BMUs along the Kenyan shores of Lake Victoria. Descriptive and inferential analyses were performed using SPSS Version 20.0. The results indicated that BMUs are successful at educating fishers and that they are aware of fishing rules and regulations. Nevertheless, high violation rates were also observed, suggesting BMUs have limited impact on fisher decisions to comply with regulations. Data suggest that the failure to comply may be due to lack of adequate financial and equipment resources for monitoring, control and surveillance (MCS) operations, making them unable to control illegal fishing in their areas of jurisdiction. Furthermore, financial mechanisms, which would allow BMUs to sustainably fund their administrative and MCS operations, are weak, thereby reducing the BMUs ability to effectively function. The data from this study highlight two activities illustrating significant indices of good performance, namely resolving disputes and receiving visitors. The data also suggest the creation of BMUs has not ensured successful implementation of co‐management of Lake Victoria fisheries. BMUs are successful at activities of a social nature, but have poorly undertaken their core functions related to enforcement and compliance with fishing rules.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/113679/1/lre12095.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/113679/2/lre12095_am.pd

USPOREDNA PERFORMANSA RASTA MUŽJAKA ISTOG SPOLA I MJEŠOVITOG SPOLA NILSKE TILAPIJE (Oreochromis niloticus L.) UZGAJANIH U ZEMLJANIM RIBNJACIMA

Comparative growth performance of male monosex and mixed sex Nile tilapia (Oreochromis niloticus) was conducted in six earthen ponds each measuring 150 m2 at the Kenya Marine & Fisheries Research Institute (KMFRI), Kegati Aquaculture Research Station. Male monosex and mixed sex of O. niloticus juveniles at an average weight of 12.2 ± 0.02 g and average length of 7.6 ± 0.02 cm were collected from nursery production ponds. The male monosex juveniles were obtained by feeding newly hatched juveniles with feed dosed with 17-α-methyltestosterone hormone for a period of one month. Stocking was at 3 juvenile m-2 and feeding was carried out using 28% crude protein diet twice daily for six months at 4% body weight. Selected water quality parameters (dissolved oxygen, temperature, pH, electrical conductivity and total ammonia nitrogen) were measured weekly in situ, while sampling for weight and length measurements was conducted on a monthly basis for a period of six months. Specific Growth Rate (SGR), Feed Conversion Ratio (FCR), Condition Factor (CF) and survival rate (%) were measured at the end of six months. Data were subjected to one-way analysis of variance (ANOVA). At the end of six months, the average weight of male monosex and mixed sex fishes was 200.8 ± 0.81 g (mean ± SE) and 123.4 ± 0.76 g, respectively, while the average length of male monosex and mixed sex was 22.4 ± 0.21 cm and 18.6 ± 0.23 cm, respectively. The male monosex O. niloticus achieved significantly increased final weight and length, SGR, FCR and CF than the mixed sex O. niloticus (p 0.05). There were no significant differences in mean water quality parameters in male monosex and mixed sex ponds (p > 0.05). The male monosex fish performed better because most energy was spent on muscle and tissue development while the mixed sex fish spent most energy on reproduction activities at the expense of muscle and tissue development. Further studies should be done in other culture systems such as liner ponds, tanks, cages and raceways.Usporedna performansa rasta mužjaka istog spola u odnosu na mješoviti spol Nilske tilapije (Oreochromis niloticus) provedena je u šest zemljanih ribnjaka veličine 150 m2 u Kenijskom institutu za istraživanje mora i ribarstva (KMFRI), Akvakulturna stanica u Kegatiju. Nedozrele jedinke mužjaka istog spola i mješovitog spola O. niloticus prosječne mase 12,2 ± 0,02 g i prosječne dužine 7,6 ± 0,02 cm prikupljene su iz mladičnjaka. Nedozrele jedinke mužjaka su dobivene hranjenjem novoizleglih ličinaka s hranom doziranom hormonom 17 α-metil-testosteronom u razdoblju od mjesec dana. Nasad je proveden u gustoći od 3 mladunca / m2 i hranidbom od 28% sirovih proteina dva puta dnevno tijekom šest mjeseci na 4% tjelesne težine. Odabrani fizikalno-kemijski parametri vode (otopljen kisik, temperatura, provodljivost i ukupni amonijak) mjereni su tjedno in situ, dok su izmjere dužina i masa provedene na mjesečnoj bazi tijekom 6 mjeseci. Specifična stopa rasta (SGR), omjer konverzije hrane (FCR), kondicijski faktor (CF) i stopa preživljavanja (%) izmjereni su na kraju perioda od šest mjeseci. Podaci su analizirani jednosmjernom analizom varijance (ANOVA). Na kraju promatranog perioda od 6 mjeseci, prosječna težina mužjaka istog spola iznosila je 200,8 ± 0,81 g (prosjek ± standardna devijacija) i mješovitog spola 123,4 ± 0,76 g, a prosječna dužina mužjaka istog spola iznosila je 22,4 ± 0,21 cm i mješovitog spola 18,6 ± 0,23 cm. Mužjaci istog spola O. niloticus postigli su značajno veću konačnu težinu i dužinu, SGR, FCR i CF nego mješoviti spol (p 0,05). Nije zabilježena značajna razlika u kvaliteti mjerenih parametara u vodi ribnjaka promatranih skupina riba (p > 0,05). Mužjaci istog spola imaju bolje rezultate jer je većina energije potrošena na mišiće i razvoj tkiva, dok je mješoviti spol trošio najviše energije na reprodukcijske aktivnosti na račun mišića i razvoj tkiva. Daljnja istraživanja bi trebala biti usmjerena ka drugim sustavima uzgoja poput obloženih ribnjaka, zatvorenih bazena, kaveza i protočnih kanala

COVID-19 disruptions and pivoting in SMEs in the hidden middle of Kenya’s potato and fish value chains

Small and medium enterprises (SMEs) in Kenya were severely affected by the COVID-19 pandemic and restrictions put in place to contain it. This study assesses the impact of these restrictions on the midstream of the potato and fish value chains, with a focus on traders and processors, and investigates the short- and longer-term responses and ‘pivoting’ strategies deployed by these firms. Longitudinal data were collected from 937 respondents with three recall periods: (1) the pre-pandemic situation (2019); (2) the period of strictest restrictions, necessitating immediate adaptations by firms (2020); and (3) a period of anticipated recovery with longer-term business adaptation strategies (2021). Firms in both value chains reported a dramatic drop in turnover in 2020. Potato SMEs partially recovered in 2021, but fish SMEs reported further declines in turnover. In the face of restrictions, SMEs shifted toward more localized procurement and sales, shorter supply chains (often by-passing intermediaries and increasing use of contracts), use of smaller vehicles, and toward the adoption of information and communication technology (ICT) to search for and engage with business partners. Smaller firms and the biggest of businesses were more resilient and less subject to large fluctuations in business turnover, suggesting an inverted U-shape relationship between firm size and impact. Firms located close to production areas and selling primarily within their own county were also less affected. We provide recommendations for increasing business resilience to shocks based on these findings

熱帯域養殖での低コストで安定的な餌料生産技術の開発に関する研究：ワムシ類（ツボワムシ科）を事例として

長崎大学学位論文 学位記番号:博(水・環)甲第31号 学位授与年月日:平成29年9月20日Nagasaki University (長崎大学)課程博