Assessment of catch composition and economic analysis of monofilament and multifilament under-meshed gears (Ngongongo) at Likoma Island, Lake Malawi

Abstract

The study was conducted to assess catch composition and economic analysis of monofilament and multifilament under-meshed gillnets (Ngongongo) from March to April 2018 around Likoma Island, Lake Malawi. Catch efficiency for targeted fish species in monofilament gillnets showed that catch per unit effort (CPUE) was three times higher than that of multifilament gillnets for Copadichromis spp. (402.2 Kg, 43.3%), Opsaridium microcephalum (315.47 Kg, 34.6%), Rhamphochromis spp. (26.2 Kg, 2.8%), Bagrus meridionalis (21.6 Kg, 2.3%), Oreochromis karongae (40.7 Kg, 4.4%), Bathyclarias spp. (23.2 Kg, 2.5%), Dimidiochromis kiwinge (14.4Kg, 1.6%) among others. Catches for Copadichromis spp. comprised of 43% for both gillnet material type combined indicating the importance of this species in gillnet fishery in the district. Monofilament gillnet caught the highest number of fish (7569) while multifilament gillnet caught the least (5427). Again monofilament gillnet has the highest weight of fish (692.87kg) while multifilament has the least (238.22kg). T-test analysis showed that the weight of fish caught by monofilament and multifilament gillnets were significantly different from one another (p=0.001). The profitability performance non-motorized monofilament and multifilament gillnets canoe fisheries in Lake Malawi (Likoma District) recorded profit margins at the end of the first year of operation with the minimum Return on Investment (ROI) of 58.9% and 34.4% respectively. On the other hand, the motorised monofilament and multifilament Gillnets canoe fisheries recorded loss 51.1% and 74.4% ROI. The study results point out to recommend for management interventions be put in place to manage the Lake Malawi fishery by imposing restrictions on effort, gear type and mesh sizes and access to illegal fishing material.

Mono- vs multifilament gillnets: effects on selectivity of narrow-barred Spanish mackerel Scomberomorus commerson in the Persian Gulf

“…There are concerns about possible increases in catching efficiency, considering several studies on other species have demonstrated relatively greater (up to ∼1.5-2.7×) catch-per-unit-of-effort (CPUE) among gillnets made from monofilament (e.g. Washington, 1973;Balik & Çubuk, 2000Balik & Çubuk, , 2004Thomas et al, 2003;Simasiku et al, 2017;Richard Winston et al, 2019). Such concerns are not only directed towards S. commerson but also several other retained (e.g.…”