Bugula simplex is an erect bryozoan found in subtidal waters of the north Atlantic. The species forms thick funnel-shaped colonies up to 3 cm in height that become tufted. The colonies are composed of multi-serial dichotomous branches that are light orange-brown or straw coloured. The branches narrow at the base and broaden at the top. Autozooids are  0.5 – 0.8 by 0.1 – 0.2 mm, with spines at the tip.

Bugula simplex is characteristics of ports and harbours in the North Atlantic where it colonises pier piles and other artificial substrates. Bugula simplex occurs on the Atlantic coast of North America (where it was wrongly identified as B. flabellata for  many years) and in the Mediterranean and Adriatic Seas. It is perhaps a more recent immigrant to south Australia and is thought to be non-native in western Europe. Until reported in the British Isles by Ryland (1958), B. simplex was known only from the Mediterranean and the eastern seaboard of North America. Recent British records include Brighton Marina and Suffolk Yacht Harbour.

Bugula simplex is generally only found for a short period over the summer, with erect portions thought not to survive the winter.

Adriatic Sea, Azores, Azores Exclusive Economic Zone, Belgian Exclusive Economic Zone, British Isles, Burghsluis, Cobscook Bay, European waters (ERMS scope), Gulf of Maine, Mediterranean Sea, New Zealand Exclusive Economic Zone, North West Atlantic, Oostende, Ouddorp, Portuguese Exclusive Economic Zone, Sas van Goes, Scharendijke, Spanish Exclusive Economic Zone, United Kingdom Exclusive Economic Zone, Wemeldinge, Wimereux, Yerseke, Zeebrugge

south of Virginia; south side of Cape cod, and extending northward of the subprovince limits, including Cobscook Bay

A recent immigrant from Southern Hemisphere: South Australia (Brock, 1985) and New Zealand (Gordon and Mawatari, 1992)

common associated with docks, harbours and piers; sessile, colonial on hard substratum epifauna in the marine environment

The bryozoan Bugula simplex was transported on hulls of cargo ships and yachts from the Mediterranean Sea to the Belgian regions. Its actual origin however is unknown. The species is bushy in appearance and was first reported in Belgium in 2000 in the marina of Ostend. Almost all observations of this species are made in ports and marinas.