The fish communities of three Nigerian lakes (Ureje, Egbe, and Ero) were assessed to
understand biodiversity status, community structure, and condition, with implications for
conservation and sustainable management. Data were collected over a period of seven
months (April–October 2024) using a combination of biodiversity metrics (species richness,
diversity indices, and relative abundance) and population health indicators (length–weight
relationships and condition factors). Water quality parameters were also measured to evaluate
their influence on fish communities.
Across the three lakes, a total of 12 fish species were recorded, with six species common to
all sites. Species richness varied slightly, with Ureje supporting seven species, Egbe eight,
and Ero nine, representing 4, 6, and 6 families respectively. Ero Lake exhibited the highest
species richness and diversity, supported by a statistically significant Margalef index (P <
0.05). Oreochromis niloticus was the most abundant species overall, while rare species such
as Heterotis niloticus were only found in Ero Lake.
Analysis of growth patterns revealed that all specimens exhibited allometric growth, with fish
from Ero Lake predominantly showing positive allometric growth (b > 3), suggesting
favorable ecological conditions. The condition factor ranged from 0.48 (Parachanna obscura
in Ureje Lake) to 3.01 (Tilapia zilli in Ureje Lake), with no significant differences between
lakes (p > 0.05). While fish abundance showed a positive correlation with dissolved oxygen
and temperature, no significant relationship was found between water quality variables and
growth coefficients or condition factors.
This integrated study highlights the role of local environmental variables in shaping fish
community composition and health. The findings provide updated baseline data crucial for
community-level conservation strategies and management actions aimed at preserving the
ecological integrity and biodiversity of these freshwater ecosystems.