GLOW 9 Synthesis: Blue Economy, a long way to go

Aquatic Ecosystem Health & Management, 24(1): 105–107, 2021. Copyright © 2021 Aquatic Ecosystem Health & Management Society. ISSN: 1463-4988 print / 1539-4077 online. DOI: 10.14321/aehm.024.01.15 At the conclusion of each GLOW Conference, a plenary session is held to discuss whether its objectives have been achieved. This year’s participants presented roughly 200 papers and posters in two and half days, which on its own was already an enormous accomplishment. All presentations were well attended and interesting discussions, albeit brief, developed after each one. Despite the attention for Blue Economy, Blue Growth Initiatives, Blue Bonds, Blue Justice and other such topics, it became clear that many a participant appeared to struggle with the “Blue” concept of their research, overviews and conclusions, as that was not always the original purpose of their studies. Consequently, many manuscripts were concerned with ongoing research, without highlighting the “Blue” aspect. Traditionally, the GLOW series of conferences centre on African Great Lakes, as well as on other Large Lakes. However, for this conference, as a result of the introduced Blue Economy concept, many marine and river papers were accepted and presented. Overall, the presentations comprised traditional fisheries papers as well as climate change and biodiversity topics, but aquaculture issues enriched this conference considerably, mainly due to emerging Tilapia cage culture in the large and great lakes as well as to crabs, seaweed and oysters in the marine sector. The interesting discussion that developed concerning the exploitation of juvenile Nile Perch versus that of adults led to surprised reactions from traditional fisheries managers; they claim that fishers should catch only adult fish that have spawned at least once, which about two decades ago yielded the “slot size” for Nile Perch. This management measure implied that perch were exploitable between 50 and 85 cm total length to protect the immature fish as well as the large spawners that could procreate millions of offspring. One of the keynote addresses discussed the amount of feed and space required for millions of new-born perch if all of them had to recruit to the fishery. In the light of the cannibalistic behaviour of the Nile Perch, it does not appear strange that they consume specimens of their own species. This theory would put fisheries management in a different light and fishing gear currently considered illegal would become efficient, allowing young fish for an ever-growing riparian human population, as markets for the juvenile fish have already developed. It became clear that the discussion on this theory has only just begun. Clearly, the GLOW conferences provide a lively platform for discussion of such topics and particularly for research on African situations not covered elsewhere. The question of illegal fishing in African waterbodies remains a topic of interest, especially whether the state should be in control, the communities or a combination of the two (co-management). Project cycles are too short to properly prepare and coach fishing communities for community monitoring, control and surveillance. Larger programmes are necessary for proper application of comanagement. Several fisheries scientists and researchers discussed overexploitation of predators in the lakes, such as the four Perch species (Lates spp.) in Lake Tanganyika, the Lake Tiger (Rhamphochromis spec.) in Lake Malawi/ Nyasa/Niassa, the Nile Perch (Lates niloticus) in Lake Victoria and the different Tiger Fish species (Hydrocynus spp.) in smaller lakes and reservoirs. The majority of the lakes experienced GLOW 9 Synthesis: Blue Economy, a long way to go