reef communities tend to develop in more or less predictable stages. First, where an ocean current encounters a vertical structure, it can create a plankton-rich upwelling that provides a reliable feeding spot for small fish such as sardines and minnows, which draw in pelagic predators such as tuna and sharks. Next come creatures seeking protection from the ocean's lethal openness—hole and crevice dwellers such as grouper, snapper, squirrelfish, eels and triggerfish. Opportunistic predators such as jack and barracuda also appear. Over months and years the reef structure becomes encrusted with algae, tunicates, hard and soft corals and sponges. 3D printing technology has been employed both to create moulds for cast ceramic and concrete artificial reefs, and to directly create artificial reefs, also through the use of environmentally friendly materials. An electrified reef is an artificial reef where a small low voltage electric charge is applied to a sub-sea metallic structures that causes limestone to precipitate onto a metal frame onto which coral planulae can then attach and grow; the process also speeds up post-attachment growth. Artificial surfing reefs Artificial surfing reefs have been created in several locations. Supporters cite benefits such as coastal protection, habitat enhancement and coastal research. The world's first attempt was made in El Segundo, near Los Angeles, in California. The next attempt was at Mosman Beach, Perth, Western Australia. This reef was constructed of large granite rocks placed in a pyramidal shape to form an appropriate breaking wave form that would suit surfers. An artificial reef constructed of over 400 massive, geotextile bags (each larger than a bus) filled with sand was constructed in 2000 at Narrowneck on the Gold Coast of Queensland, Australia. This artificial reef had two objectives: stabilizing beach nourishment and improving surfing conditions. Europe's first artificial reef was approved in 2008. Construction began August 30, 2008, in Boscombe, Bournemouth, UK (5 months after 3 local councillors spent 18 days in New Zealand on a fact-finding mission), and opened in November 2009. The £3 million (2.5% of the Council's annual budget that year) reef was expected to create waves up to 30% larger and double the number of surfing days annually. Construction on this reef continued from June 2008 through August 2009. Boscombe Reef was built from large sand-filled geotextile containers, totaling . It failed entirely and attempts were made to convert it into a multi purpose reef, which also failed. Bournemouth Council