The seaweeds of Kenya: Checklist, history of seaweed study, coastal environment, and analysis of seaweed diversity and biogeography

J.J Bolton,H.A Oyieke,P Gwada

doi:10.1016/j.sajb.2006.08.006

Abstract

The seaweeds of Kenya are relatively well documented in comparison with the marine floras of other countries in the Indian Ocean. A checklist is provided of the seaweeds recorded, which includes a total of 386 species (214 red algae, 116 green algae and 56 brown algae), plus an additional 19 infra-specific taxa. This is the first detailed list for almost 30 years, with a 29% increase in species compared to the previous listing. The history of seaweed study in Kenya and the Kenyan coastal environment as a habitat for seaweeds are discussed in detail. An ordination analysis of the global biogeographic relationships of the Kenyan seaweed flora shows clearly the internal consistency of the Indo-Pacific seaweed flora at this large scale. Data on Indian Ocean relationships show that the Kenyan flora produces a distinct grouping of seaweed floras from Tanzania, Madagascar, Mozambique and the Indian Ocean coast of South Africa, which is somewhat separated from the floras of the rest of the Indian Ocean. The data reveal that Mozambiquan seaweeds are seriously understudied, with only 26% of the Kenyan flora having been recorded in that country, compared with 68% in Tanzania, 41% in Madagascar, and 43% in South Africa.

Highlights

The seaweeds of Kenya are fairly well-studied floristically, relative to other Indian Ocean countries (Coppejans et al, 2001; Bolton et al, 2003)
The analysis reveals that the Indo-Pacific region forms a very distinct cluster, including East Asia, Australia/New Zealand, Southeast Asia, and the Pacific Islands
In general, the number of seaweed species in a region is related to coastal length in a log/log relationship (Santelices et al, in press), and Kenya does not necessarily have an especially rich flora in an Indian Ocean context

Summary

Introduction

The seaweeds of Kenya are fairly well-studied floristically, relative to other Indian Ocean countries (Coppejans et al, 2001; Bolton et al, 2003). The biogeographic affinities of the Kenyan seaweed flora have not previously been analysed in detail This contribution documents the history of seaweed study in Kenya, describes the coastal. Environment as a habitat for seaweeds, lists the species which have been recorded, and analyses the biogeographic patterns of distribution of the seaweeds which have been recorded in Kenya, both in the Indian Ocean and worldwide. It comprises Phaeophyceae, Chlorophyta and Rhodophyta, omitting the Cyanophyta (=Cyanobacteria) which, despite the listings in Silva et al (1996), are much less well studied than the other three groups, and have taxonomic and nomenclatural problems

History of seaweed study in Kenya

The Kenyan coastal environment

Methods of checklist production and biogeographical analysis

Results of biogeographic analysis

Discussion