Trends in anchovy catches and the influence of Chlorophyll-A and sea surface temperature in Kilwa, Tanzania: A case of anchovy at Kivinje and Masoko-Kilwa

Trends in anchovy catches and the influence of Chlorophyll-A and sea surface temperature in Kilwa, Tanzania: A case of anchovy at Kivinje and Masoko-Kilwa

Anchovy fisheries exhibit varying trends worldwide, with some regions experiencing declines due to overfishing and environmental changes, while others remain stable or even increasing. This study aimed to assess trends in anchovy catches in Kilwa District, Tanzania, and their relationship with environmental factors. We monitored catches at Kilwa Masoko and Kilwa Kivinje during both the northern eastern monsoon (high season) and the southern eastern monsoon (low season). Contrary to our expectations, the results revealed an increasing trend in anchovy catches at both sites. Catches were consistently higher in Kilwa Kivinje than in Kilwa Masoko and peaked during the high season (Fisher’s PLSD; p < 0.0002). The catch was composed of two species; Stolephorus commersonnii, and Encrasicholina devisi which dominated in the catches. We found that anchovy catches were positively linked to chlorophyll-a levels [(R² = 0.763, t = 6.215, p < 0.0001) Masoko, (R² = 0.597, t = 4.215, p < 0.012) Kivinje], but negatively associated with sea surface temperature. Additionally, the increase in catch per unit effort suggests that overfishing is not yet a concern, despite the rising catches. These findings provide valuable insights for the sustainable management of anchovy fisheries in Kilwa District.