Background:

The benthic phycological flora of the Colombian Pacific is found in one of the less known areas of the eastern tropical Pacific, with a total registry of 133 species. Algal biodiversity on the Pacific Coast is relatively low, compared to the Colombian Caribbean, where previous research has registered about 549 species.

Goals:

This study evaluated the marine macroalgal flora of Tumaco Bay, southern Colombian Pacific, including inventory, species description, and new records in this coastal region. Methods. Algal material was collected from rocky shores and estuarine creeks within the bay between May and December 2009, and March to October 2010. Subtidal algal specimens were collected with scuba. Further, the study recorded additional species and new species locations in the region.

Results:

The study registered a total of 26 species, of which eight are Chlorophyta, two are Ochrophyta-Phaeophyceae, and 16 are Rhodophyta. These records were distributed in nine orders, 14 families, and 19 genera. The study described the coastal habitats within the bay and the relationships between ecological features and species distribution. Descriptions of each species included morphological data, habitat, and species distribution.

Conclusions:

Tumaco Bay exhibited low algal diversity (26 species) when compared to studies on Gorgona Island, and along the shores of Costa Rica, Panama, El Salvador, Nicaragua, and Guatemala, with 42, 216, 174, 146, 24, and 16 species, respectively. Similar results have been recorded on the Pacific coasts of Nicaragua and Guatemala, with registries of 24 and 16 algal species, respectively.