DIVERSITY AND DISTRIBUTION OF HARMFUL CENTRIC DIATOMS (Baccillariophyceae) IN BONNY ESTUARY, NIGER DELTA, NIGERIA

Abstract

A survey of algal species in the Bonny Estuary was carried out in seven sampling stations between December,
2017 and May, 2018 to determine the diversity and abundance of harmful centric diatoms in the
Bonny Estuary. Plankton samples were collected with 20µm mesh plankton net to provide a quantitative account
of harmful algae species, some physico chemical characteristics of water in the Estuary was also determined. The
harmful centric diatom recovered were a total of eleven species in four families. Odontella. Aurita recorded the
highest percentage abundance (14.57%) followed by Coscinodiscus meneghiniana (13.95%) and the
least was Coscinodiscus concinnus with (1.60%).The mean density value recorded ranged between 34.08 x 10ce
ll/L and 639.35 x 10cell/L.The Shannon index recorded the highest value of 2.292 in station 4, followed by 2.271
in station 1 while the least value of 2.076 was recorded in station 3.Dominance_D was highest in station 3 with
value of 0.1483, followed by 0.1318 in station 6 while the lowest value of 0.1093 was recorded in station 4. The
highest Margalef value of 1.441 was recorded in station 1, followed by 1.438 in station 2, while the least value of
1.393 was recorded in station 7. The biotic indices of centric diatom were fairly well distributed in the Bonny
Estuary, which shows the centric diatoms are stable. This study therefore, provided information on the diversity
and distribution of harmful centric diatoms in the Bonny Estuary