Eastern Atlantic expedition: submersible and scuba collections for bioactive organisms from the Azores to Western Africa

Research expeditions conducted by Harbor Branch Oceanographic Institution on the R/V Sea Diver in 1990 and on the R/V Seward Johnson in 1991 explored the waters of the Azores, Madeira Islands. Salvage Islands, Canary Islands, Republic of Cape Verde, and the west African countries Senegal and Sierra Leone. The objectives were to collect marine macro- and microorganisms for the purpose of isolating novel, biologically active compounds with potential as therapeutic agents for human diseases. A total of 1,756 samples of macroinvertebrates and algae were collected at 254 sites, utilizing submersible. scuba, trawl, and dredge. During 69 operational days, 28 diver-scientists using DCIEM dive tables made 547 dives, totaling 403 hr bottom time, to depths of 40 m. Deep-water (40 - 914 m) collections with the Johnson-Sea-Link I submersible discovered rugged, steep volcanic slopes off Madeira, Salvage and Canary Islands, and also dense populations of black coral, gorgonians, and sponges. The dominant taxa consisted of Porifera (49.6%), Cnidaria (19.3%), Rhodophyta Echinodermata (8.0%), Phaeophyta (6.2%), Ascidiacea (5.9%), Chlorophyta (2.7%) and Mollusca (2.0%). Biological affinities of many of the algae, cnidarians, sponges, and ascidians from Azores, Madeira, Salvage and Canary Islands are Mediterranean and west African. In contrast, the benthic communities in the warmer water of Cape Verde, Senegal, and Sierra Leone had more tropical and Caribbean similarities. Biological activities of sample extracts were tested with cytotoxic (P388), antitumor (A549), cell adhesion (EL4), and antifungal (Candida albicans) assays. Of the 759 samples tested, approximately 10% showed bioactivity.