M (2017) Identification of Tilapia Lake Virus in Egypt in Nile tilapia affected by 'summer mortality' syndrome, Aquaculture, 473, pp. 430-432.

Warm water aquaculture is widely practiced in Kenya and is dominated by the culture of Nile tilapia (Oreochromis niloticus) (75% of total production) followed by African catfish (Clarias gariepinus) at 18%. Aquaculture started in Kenya in 1920’s and has been on upward trend until 2014 when it peaked at 24,096 MT. However, production reduced drastically in the past 3 years, with 14,952 metric tonnes (MT) reported in 2016. Most farmers practice earthen pond based semi-intensive culture system. Commercial intensive culture of Nile tilapia (O. niloticus) in cages in Lake Victoria has grown significantly in the last five years with a production of 12 million kg of fish every cycle (about 8 months). Recirculation aquaculture system (RAS) is also gaining popularity mainly in intensive hatcheries. The freshwater cages have been marred by increasing frequencies of fish kills with obvious financial and environmental implications. Although limited information exists on fish disease outbreaks across the country, certain well known diseases in farmed fish have been reported. These include; fungal, mainly saprolegniasis, bacterial, mainly hemorrhagic disease and pop-eye diseases. Parasites have also been documented in farmed O. niloticus and C. gariepinus. Although prophylactic treatments are used in some hatcheries in order to prevent infections, limited biosecurity measures are in place to prevent diseases in farmed fish. This is because of inadequate knowledge of the economics of fish diseases, poor infrastructure and inadequate human resource specialized in fish diseases. This review describes the aquaculture production and health mangement practices of farmed fish in Kenya in order to document actions required for effective monitoring and regulation of future fish health problems across the country.

A 32‐day experiment was conducted to evaluate the effects on the performance, feed utilization efficiency and body composition of a strategic inclusion of Black Soldier Fly larvae meal (MM) in a commercially formulated diet for advance nursing Nile tilapia (Oreochromis niloticus). Four isonitrogenous and isoenergetic diets were commercially formulated and manufactured as a control and three test diets with strategic inclusions of MM inclusions (0, 30, 50 and 80 g/kg) and poultry by‐product meal substituting gradually three conventional expensive feedstuffs: fish meal, fish oil and soybean meal. Fish (5.7 ± 0.5 g/fish) were nursed in a cage‐in‐lake system (Volta Lake, Ghana), under conditions similar to commercial farming practices. Control and experimental diets were fed to triplicate cages by hand to visual satiety, six times per day. Growth performance (final weight; weight gain and SGR), feed utilization efficiency indices (FCR and PER) and feed intake were not significantly different (p ≥ .05) between treatments. Survival was significantly different (p < .05) but more likely explained by the stress related to frequent handling on the smaller fish. Fish whole body composition (dry matter, crude protein, lipid, ash and fibre) was unaffected by the treatment (p ≥ .05), except for the fatty acid compositions which mirrored that of the diets.

Fishmeal is an important source of high quality protein in aquaculture, but concerns about its cost 13 and sustainability are making it a less attractive feed material. Replacing fishmeal with plant pro-14 teins can impact on the nutritional quality of farmed salmon. In theory insect meals could be substi-15 tuted for fishmeal without affecting the quality of the fish produced. They could also provide a way 16 of adding value to the bio-wastes used to rear the insects. However little is known about consumer 17 or producer attitudes towards the use of insect meals. This paper reports findings of a survey of 18 consumer attitudes in the UK, towards the incorporation of cultured insect larvae (maggots) -de-19 rived feed materials into commercial formulated fish feeds for the Scottish Salmon farming sector. 20It also investigates the attitudes of other stakeholders (salmon farmers, feed producers and fish re-21 tailers) via semi-structured interviews. Consumer attitudes towards the use of insect meal were 22 found to be favourable (only 10% were opposed to the inclusion of insect meal in salmon feed 23 n=180), with vegetable waste being the preferred waste stream for rearing insects. The interviews 24 suggest that feed and salmon producers are in principle open to the use of insect meals, provided the 25 feeds are proven to be safe and reliable. However producing insect meal in sufficient quantity, qual-26 ity and at a price that is competitive with existing feed materials will be challenging. 27 28

This paper explores the development of a sustainable production system for tilapia and the research implications involved with ensuring commercial viability of such a system for UK farmers. The tilapia is a warm water fish with firm texture, white flesh and mild taste quite similar to a cod or haddock. Whilst tropical in origin it is thought to be highly suitable for low cost aquaculture in temperate zones with the potential to be a more sustainable source of food with fewer environmental impacts than other substitutes. Drawing on a literature review and findings from technical trials the paper will review and compare two production systems -novel Activated Suspension Technology (AST) and conventional Recirculating Aquaculture Systems (RAS) -considering their feasibility in terms of potential and financial viability for scaling up to commercial production of tilapia and their environmental and sustainability benefits. The review concludes that AST based only on microbial floc is currently uncompetitive with RAS in a UK context although the approach has benefits that might be incorporated in a new generation of mixed systems. Refinement of such systems needs to occur with potential adopters and could be part of diversification of mixed farms. Such development might further enhance the ethical values of fish produced in small-scale, modular RAS.