Perceptions of rule-breaking related to marine ecosystem health

Finding effective solutions to manage marine resources is high on political and conservation agendas worldwide. This is made more urgent by the rate of increase in the human population and concomitant resource pressures in coastal areas. This paper links empirical socio-economic data about perceptions of marine resource health to the breaking of marine management rules, using fisheries as a case study. The relationship between perceived rule-breaking (non-compliance with regulations controlling fishing) and perceived health of inshore marine environments was investigated through face-to-face interviews with 299 heads of households in three Tanzanian coastal communities in November and December 2011. Awareness of rules controlling fishing activity was high among all respondents. Fishers were able to describe more specific rules controlling fishing practices than non-fishers (t = 3.5, df = 297, p < 0.01). Perceived breaking of fishing regulations was reported by nearly half of all respondents, saying “some” (32% of responses) or “most” (15% of responses) people break fishing rules. Ordinal regression modelling revealed a significant linkage (z = −3.44, p < 0.001) in the relationship between respondents' perceptions of deteriorating marine health and their perception of increased rule-breaking. In this paper, inferences from an empirical study are used to identify and argue the potential for using perceptions of ecosystem health and level of rule-breaking as a means to guide management measures. When considering different management options (e.g. Marine Protected Areas), policy makers are advised to take account of and utilise likely egoistic or altruistic decision-making factors used by fishers to determine their marine activities

Spatial patterns of zooplankton distribution and abundance in relation to phytoplankton, fish catch and some water quality parameters at Shirati bay, lake victoria-Tanzania

Spatial patterns and abundance of zooplankton in aquatic habitats are important determinants for production of fish species, invertebrates and availability of phytoplankton. Weekly monitoring for zooplankton abundance was conducted in Shirati Bay, Lake Victoria, to explore their spatial patterns in relation to phytoplankton, fish catch and some water quality parameters. The vertical distribution of zooplankton was generally higher close to the bottom as compared to surface waters of the lake. Zooplankton vertical distribution positively correlated with water transparency (r = 0.680, p = 0.011). The horizontal abundance of zooplankton was not significantly different amongst the three stations (p = 0.5143). While Copepoda was the dominant group in terms of composition, Rotifera had the highest diversity indices of all the zooplankton groups obtained. The abundance of nauplius larvae was significantly higher than that of the copepodites (p = 0.022). Nile perch, Lates niloticus dominated the total catches (47%) followed by Nile tilapia, Oreochromis niloticus (29%) and haplochromines (21%). The abundance of haplochromines and juvenile fishes correlated significantly with the abundance of zooplankton (r = 0.856, p = 0.002 and r = 0.58, p = 0.038, respectively). The current study revealed that zooplankton vertical distribution at Shirati Bay is mainly controlled by water transparency and predation by juvenile Nile perch, Nile tilapia and haplochromines.Keywords: chlorophyll-a; calanoid; cyclopoid; nauplius larvae; juvenile fis

Fisheries Statistics for Lake Victoria, Tanzania

This research article published by Springer Nature Switzerland AG., 2017Time series fisheries statistics data mainly from Frame Surveys, Catch Assessment Surveys and Fisheries Annual Statistics Reports for Lake Victoria from 1967–2016 were collected from the Fisheries Development Division in Tanzania. These surveys and reports comprised relevant information and data on fish catches and fishing effort. The data were analysed and used to describe variations and trends in the number of fishers, number of fishing crafts, fish weight, catch per boat, total number of gillnets, beach seines, longline hooks, outboard and inboard engines. Frame Survey results showed an increasing trend in the number of fishers and fishing crafts, with the highest number of fishers and fishing crafts being 109,397 and 31,773, respectively in 2016. Longline hooks increased from 2,200,901 in 2000 to 8,163,119 hooks in 2016. In general, the catch per unit effort (CPUE) for all species was high at 39 mt/boat/year in 1967 and decreased to 8 mt/boat/year in 2014. However, CPUE for Lates niloticus has increased since the late 1980s, with the highest CPUE of 19.22 mt/boat/year being recorded in 1995, and from 2000 it decreased gradually to 7 mt/boat/year in 2014. As the fisheries statistics show an increase in fishing pressure over the years, it is evident that there is a sign of overfishing. For that matter, effective fisheries management is needed for the three riparian states to safeguard the sustainable use of fishery resources in the lake and to provide data that can be used in the evaluation of the fisheries objectives

Co-management of Lake Victoria Fisheries

This research article published by Springer Nature Switzerland AG., 2017There have been concerns about the declining fish catches and fisheries ecosystem health for a number of fisheries including Lake Victoria. Consequently, a co-management system has been introduced as a means of, among others, reversing the declining catches. It is hypothesized that non-involvement of fishers in the management of the lake’s fisheries is a major reason for the ever-decreasing catches. This chapter discusses this particular management regime and its application in the lake’s fisheries. The analysis is based on data collected by the Fisheries Division since co-management was introduced in the lake in 1998. The chapter traces the lake’s fishery management since the pre-colonial to the post-colonial period. It presents the aim and rationale for managing the lake’s fishery, the structure of the management and roles of governors. It also analyses trends in illegal fishing practices as well as enforcement performance. The argument here is that co-management has helped in bringing on board fishers and this has enabled laws and regulations to be implemented in a much better way than they were under a central-command system. The chapter subsequently concludes that the involvement of fishing communities in the management of fisheries has created a forum for the exchange of ideas, knowledge and experience on the resources. This strategy has made the communities understand the importance of compliance to the law and regulations and effective management measures

Environmental Changes in the Tanzanian Part of Lake Victoria

This research article published by Springer Nature Switzerland AG.,Lake Victoria is known for its explosive speciation and recent time hybridization, which is highly mediated by deterioration of water quality. This chapter summarizes the knowledge on change of water quality and environment of southern part of Lake Victoria, Tanzania. It analyses rainfall, air temperature and water quality data spanning 30 years (1985 to 2015). It also investigates changes in physical-chemical data sampled during and after the Lake Victoria Environmental Management Project I (LVEMP I). The chapter reviews some of the significant water quality changes that have occurred for the past 50 years. The results indicate no significant changes in annual rainfall variability. Nevertheless, trends of air temperature showed no clear patterns for Mwanza and Musoma, but trends of minimum and maximum air temperature in Bukoba increased significantly at annual rates of 0.19 °C and 0.14 °C, respectively. Water level in Lake Victoria has also declined significantly at an annual rate of about 5.5 cm from 1965 to 2004. These findings suggest that lake levels are determined by evapotranspiration rather than rainfall. It was also found that anthropogenic stressors are more important in explaining nutrients loading while thermal stratification explains hypoxia and reduction in water mixing. It is concluded that the current blooms of harmful algae and excess biomass in Lake Victoria will continue unabated unless nutrient loading, anoxia and high rates of denitrification are curbed. Appropriate measures to improve land use management should therefore be taken, while deliberate dumping of industrial, municipal and agricultural wastes into the lake should be controlled

Lake Victoria Environmental Management Program (LVEMP): Regional synthesis report on fisheries research and management: states, trends and processes

During the past eight years of the LVEMP project (Phase I) the various components have been able to collect considerable amounts of data and information. The outputs, however, in the form of the analyses, results, reports and papers, are to a large extent isolated to just cover the activity of the individual component, and much of the findings are of a descriptive nature (e.g. LVEMP 2005). Results therefore become fragmented and analytical output is rarely integrated across disciplinary boundaries. Lack of prioritisation in research has lead to a large output of activities and papers that in some cases duplicates already known work. The research activities have not as yet lead to strategic conclusions on the future focus of research, monitoring, investments and preventive measures, nor has it been translated into a holistic understanding of the ongoing processes or integrated management actions

Distribution of occupations by village and all respondents, n = 292.

<p>Distribution of occupations by village and all respondents, n = 292.</p

Map of Tanzania with expanded area central coast of Tanzania indicating position of coastal villages from North to South: A. Ununio, B. Kunduchi, and C. Buyuni.

<p>(Source <a href="https://www.cia.gov/library/publications/cia-maps-publications/Tanzania.html" target="_blank">https://www.cia.gov/library/publications/cia-maps-publications/Tanzania.html</a>).</p

Ordinal regression model (logistic) all respondents' responses to perception of rule-breaking for rules controlling fishing.

<p>(a) Retained explanatory variables all respondents (n = 201). (b) Threshold coefficients: (log-likelihood: −241.1900, AIC: 494.3801, Condition number of Hessian: 2288.399).</p