ABSTRACT
Artificial reefs composed of over 7000 scrap tires and 400 Christmas trees, and covering about 9500 m2, were installed in Smith Mountain Lake, Virginia, during summer and fall 1973. Over 50 percent of the total estimated cost of reef construction was donated by the local community.
Sport fishes were significantly more abundant on the experimental reef sites during both years after reef construction (1974 and 1975) than before reef installation. Sunfishes (Lepomis spp.) and white catfish (Ictalurus catus) were the most common, but centrarchid basses (Micropterus spp.) were also plentiful. Fishes moved onto reefs in the spring as water warmed and off the reefs in late fall as the water cooled. Sunfishes preferred low profile reef units in shallow water (1.5 m), and the basses preferred high profile reef units in deeper water (4.6-6.1 m). Nest building basses spawned adjacent to the reef units, sunfishes inshore from the shallowest reef units, and cavern-seeking catfishes directly on the reef substrate.
402Primary productivity and nutrient levels of periphyton on the tire reef were higher than similar measures of littoral phytoplankton. Periphyton communities attached to the tire reefs were the major food and ultimate source of energy of the reef sport fish community. Body condition was better and growth in weight faster in sunfishes from reef areas than in those from areas with natural structure or no structure.
Seasonal climatic changes in temperature and morphometric features of the basin of Smith Mountain Lake influenced the movement of largemouth bass (Micopterus salmoides) and bluegills (Lepomis macrochirus). Bass and bluegills on reefs confined most of their summer movement to littoral reef areas. After thermal destratification, fish moved offshore into deeper water away from the reefs.
Experimental fishing surveys, SCUBA surveys, and trapping and netting surveys showed that: (1) sunfishes preferred tree reefs to tire reefs in spring; and (2) reefs effectively concentrated fishes. A recent (1983) SCUBA survey of the tire reefs indicated that the structures were still about as effective as they were in 1974 and 1975.
