Variations in community perceptions of ecosystem services within the Tana River estuary, Kenya: Implications for ocean governance

Coastal communities in the Tana estuary, Kenya, rely on a variety of economic sectors linked to ecosystem services, including small-scale fisheries (SSF), commercial prawn fisheries, and tourism. Despite its environmental and social importance, the estuary has been negatively impacted by overexploitation, pollution, and climate change. As a result, developing integrated management approaches for this area is a priority. The integrated approach to ecosystem services (ES) evaluation has widespread support because it emphasizes people’s views of ecological value to human well-being and aims to provide a solution to the rapid depletion of our planet’s natural resources. This study applied mixed methods to understand the perspectives of the communities on ES. It was hypothesized that perceptions of ES differ across communities with different socioeconomic characteristics, and this hypothesis was tested in two communities (Ozi and Kipini) that share the same ecosystem but have different socioeconomic characteristics. Kipini is an area near the ocean, whereas Ozi is a rural area further upstream. Differences were noted in the valuation of cultural services, while there were similarities in provisioning and regulating services. Mangroves, other trees, and river systems were considered to have higher ES provision than the ocean, floodplains, and settlement areas. The Ozi community ranked the ocean higher than the Kipini community, even though Ozi was located further upstream from the ocean; consequently, the perception that communities benefit more from resources that they are close to could be false. The relevance of using social ES identification to determine the distribution of benefits from coastal ES is highlighted in this study and will be beneficial for informing decision-making and developing all-inclusive governance structures

Fish markets facilitate nutrition security in coastal Kenya : Empirical evidence for policy leveraging

Fish markets are key to supporting the availability and accessibility of nutritious food but are often overlooked in food and nutrition research and policy. This study investigated fish markets in coastal Kenya, using data from 223 semi-structured interviews collected through market surveys, and analyzed their potential to meet recommendations for consumption and alleviate malnutrition in a vulnerable coastal population (children under five years). Findings reveal that women small-scale traders dealt in lower quantities of fish per trader than the other traders, yet sold more nutritious fish. Fish shop traders sold enough fish to meet 129% of the recommended intake of fish (10.4 kg cap−1 yr−1) for all people within the assessed towns, whereas women small-scale traders sold enough to meet 84% of the intake. All market traders were key to making nutrient-dense fish available, with a 100 g portion of fish providing at least 25% of required intakes, across five nutrients, and women small-scale traders providing over 25% of required intakes across six nutrients for a child under five years. The average cost of a nutritious portion of fish was KES 31 (USD 0.22), ranging from KES 12 (USD 0.08) to 49 (USD (0.34), which provide 33.3% of the required nutrients (averaged across six nutrients), with nutrient-dense fish being notably cheaper. This study contributes empirical evidence on how territorial fish markets support nutrition, which is important for food policy interventions that promote nutritional literacy, address nutrient gaps, and improve postharvest practices and infrastructure for fish quality and safety in Kenya

Stock assessment of the Tigertooth croaker, Otolithes ruber (Bloch & Schneider, 1801) from the commercial prawn trawl fishery by-catch in coastal Kenya

Commercial bottom prawn trawling has been reported to generate a higher proportion of by-catch of up to 70% in Kenya. The Tigertooth croaker, Otolithes ruber is one of the species caught in large quantities as commercial by-catch and also by artisanal fishers. This has led to growing concern that the species could be at risk of over-exploitation. The purpose of this study was to carry out a stock assessment of O. ruber. Stock assessment parameters were estimated using ELEFAN with the generic algorithm as included in the R package TropFishR. The length-converted catch curve and the length-based yield per recruit model were employed. The exploitation rate (F/Z = 0.71) indicates that the stock is overfished based on the length-converted catch curve. The current fishing mortality (F = 2.3) based on the catch curve is larger than the reference level ( = 1.1) based on the yield per recruit analysis and also indicates that the stock is overfished (= 2.09). To reverse the current trend of exploitation, improved management of the stock is required, which should include further studies on other by-catch species and the generation of data to capture the whole fishery for a better estimation of stock status

Propulsion-gear-based characterisation of artisanal fisheries in the Malindi-Ungwana Bay, Kenya and its use for fisheries management

In Kenya, like other tropical countries, coastal artisanal fishery is multispecies, multigear and multifleet in nature with many management challenges. The Malindi-Ungwana Bay in particular, supports both the artisanal fishery and the semi-industrial bottom trawl shrimp fishery presenting a management challenge. Recent stock assessment surveys have identified catch composition of the semi-industrial bottom trawl fishery in the bay but artisanal catches remain barely described. This study describes, the artisanal fish catch composition (total number of species caught, sizes and trophic levels), and catch per-unit-effort (CPUE) for each of the most popular propulsion-gear categories used in the bay. We make a case that the use of specific propulsion-gear categories can be dynamically managed to encourage the recovery of selected fish groups and thus support fisheries management. A total of 4 269 finfish belonging to 177 species and 66 families were sampled by the 5 most popular propulsion-gear categories between 2009 and 2011. The total number of species caught was highest for canoe-gillnet, mashua-gillnet and foot-seine net, and lowest for foot-handline and mashua-handline. Significant differences in catch composition existed between the different propulsion-gear categories. The CPUE was not significantly different between propulsion-gear, although this was on the average highest for canoe-gillnet and mashua-gillnet, and lowest for the foot-handline. The highest trophic level of 4.0 was recorded for mashua-gillnet and the lowest 3.4 and 3.2 for canoe-gillnet and foot-seine net respectively. The use of specific combinations of propulsion-gear categories, give an alternative approach in management recommendation of the coastal artisanal fisheries in the tropics, from the traditional gear-based management initiative. This study, singled out the mashua-gillnet, canoe-gillnet and foot-seine net as suitable units for monitoring the artisanal fisheries in Malindi Ungwana Bay since mashua-gillnet lands the highest mean trophic level and largest sized individuals, and canoe-gillnet and foot-seine net land the highest number of species caught and smallest sized individuals

Fisheries Centre research reports, Vol. 28, no. 1

This volume investigates the consequences from the effective ban of different fishing gears at Nyali-Mombasa, a site on the Kenyan coast. Using ecosystem modelling, it explores different scenarios for evaluating high-level impacts of various intervention or management decisions, as well as the resulting socio-economic consequences on relevant communities. The work has mapped various aspects of the Nyali-Mombasa ecosystem through the creation of a food web model, reproducing and quantifying main energy flows, and holistically investigating dominant food-web dynamics, and the role of fisheries on the system. With the exception of a simple Maputo Bay model (Silva et al. 1993), this research is the first to develop an Ecopath model for a coastal area in East Africa.Science, Faculty ofNon UBCOceans and Fisheries, Institute for theUnreviewedFacultyResearche

Participatory assessment of priority fishery profiles in an overfished urban inshore seascape in Kenya

This study presents a participatory assessment of overfished small-scale fisheries from selected landing sites in coastal Kenya using mixed quantitative and qualitative research methods. A seven-criteria ranking using a modified Delphi questionnaire with a 5-point Likert scale was used. Through a process of scoring the fisheries on these crite- ria, marine aquarium fishing ranked highest with 86.7%, while beach seine ranked lowest at 55.3%. Averaging of scores and ranking across focus group discussions (FGDs) and key informant interviews (KIIs) at individual sites resulted in the following highest scorers: handlines (58.6%), octopus (55.9%), and basket traps (52.5%) for Bamburi; aquar- ium fishing (86.7%), handlines (85.5%), and reef-seines for Marina/Mtwapa; mixed pelagic (60.7%), octopus (60.5%), and rabbitfish (58.4%) for Nyali; and basket traps (70.4%), handline (57.8%), and monofilament nets (64.3%) for Reef. Destruction of critical habitats and prohibitive costs of fishing crafts were key management issues identified through scoring and ranking criteria, while 22 management issues were identified through FGDs. These findings suggest an existing spatial mixture of differences and commonalities among fisheries profiles and management issues. This study revealed trade-offs that should be incorporated in the co-management plans of the respective Beach Management Units (BMUs) in coastal Kenya

Diversity of Shallow-Water Species in Prawn Trawling: A Case Study of Malindi–Ungwana Bay, Kenya

Bottom trawling is a common fishing method that targets bottom-dwelling fisheries resources. It is non-selective and large amounts of by-catch are discarded, raising serious sustainability and ecosystem conservation concerns. In this study, a shallow-water bottom-trawl fishery was evaluated using logbook catch data between 2011 and 2019 and the species composition data collected by fisheries observers between 2016 and 2019. The logbook data showed a twenty-fold increase in the annual catches with a ten-fold increase in fishing effort and an increase in the proportion of retained catch from 2011 to 2019. The observer data showed that for prawn, the by-catch ratio ranged from 1:3 to 1:9 during the four years. Multivariate analysis revealed significant differences between the compositions of retained and discarded catches mainly attributed to Pellona ditchela, Nematopalaemontenuipes, and Secutor insidiator. There was no significant decline in species diversity and the trophic level of the catches over the 4-year observer period indicating no marked impact of trawling on the stock at the current level of fishing effort. This study provides baseline information on the prawn trawl fishery against which the performance of the management regulations may be evaluated towards the Ecosystem Approach to Fisheries management

Diversity of Shallow-Water Species in Prawn Trawling: A Case Study of Malindi–Ungwana Bay, Kenya

Bottom trawling is a common fishing method that targets bottom-dwelling fisheries resources. It is non-selective and large amounts of by-catch are discarded, raising serious sustainability and ecosystem conservation concerns. In this study, a shallow-water bottom-trawl fishery was evaluated using logbook catch data between 2011 and 2019 and the species composition data collected by fisheries observers between 2016 and 2019. The logbook data showed a twenty-fold increase in the annual catches with a ten-fold increase in fishing effort and an increase in the proportion of retained catch from 2011 to 2019. The observer data showed that for prawn, the by-catch ratio ranged from 1:3 to 1:9 during the four years. Multivariate analysis revealed significant differences between the compositions of retained and discarded catches mainly attributed to Pellona ditchela, Nematopalaemontenuipes, and Secutor insidiator. There was no significant decline in species diversity and the trophic level of the catches over the 4-year observer period indicating no marked impact of trawling on the stock at the current level of fishing effort. This study provides baseline information on the prawn trawl fishery against which the performance of the management regulations may be evaluated towards the Ecosystem Approach to Fisheries management

Natural resource-use in the Lower Tana River Delta based on household surveys and remote sensing of land cover and land use patterns

Household survey data and spatially explicit Sentinel-2 satellite images of land cover and land use during the dry and wet seasons were used to investigate livelihood strategies in the Lower Tana River Delta in Kenya, where food security and economic activity rely almost exclusively on ecosystem goods and services. Land cover classification of satellite imagery successfully showed seasonal changes to estuary-related vegetation and habitats from which land use cycles could be inferred. Flood-recession agriculture and part-time fishing were the most common activities at Ozi village, some 10 km upstream from the estuary mouth, whereas full-time fishing dominated activities at Kipini town, where the Tana Estuary discharges into Ungwana Bay. Seasonality of fishing at Kipini depended on favourable sea conditions, arrival of migrant fishers and peaks in shrimp abundance. Seasonality of agriculture at Ozi depended on the freshwater flooding regime, visible in satellite images as an inverse relationship of areas covered by wetlands and cultivated lands. The predominance of fishing assets at Kipini indicated specialization, which underlies a socio-economic network of fish processing, marketing, distribution and logistical support services. In contrast, mixed farming assets and traditional fishing gear at Ozi reflected more diversified farmer-fisher livelihoods, as a risk avoidance strategy. Key outcomes of this study were that land cover and land use were strongly seasonal, that coastal and upstream communities in the Tana Estuary relied on different combinations of ecosystem goods and services, and that livelihood strategies at the two locations differed fundamentally. Combining social, spatial and ecological data to describe socio-ecological systems typical of the Tana Estuary provided a broad platform for shared resource management strategies