A film about the environmental problems of the Black Sea. Expedition of the international independent company "Ecology of the Sea" ("Ecosi") on the research vessel "Akademik Boris Petrov". Scientists take water samples, explore the underwater world of the sea and its inhabitants. Director of the company "Ecosi" Professor V. Keondzhyan gives interviews (synchronously). Sea shore. Algae on the shore, oil dripping from a pipe, a garbage dump, a dump of abandoned ships, a dead dolphin on the shore, oil in the sea. Waste pipe in the sea. Scientist S. Mavrodiev from Bulgaria gives interviews (synchronously). The ship "Akademik Vernadsky" in the port of Varna. International conference "Black Sea-90". Speakers are conference participants, including S. Mavrodiev.