Final answer:
A buoy with a "composite group" flashing green light is used for maritime navigation. The ability of an electric power-generating buoy to withstand harsh conditions, like Hurricane Irene, underscores the durability of these devices. Buoys can accumulate marine organisms, affecting their function and requiring maintenance.
Step-by-step explanation:
A buoy that displays a "composite group" flashing green light typically indicates navigational information for vessels at sea. This particular type of light signaling is used to guide ships by indicating safe passage or warning of potential hazards.
The mention of an electric power-generating buoy that survived difficult conditions, such as operating off the New Jersey coast during Hurricane Irene, highlights the resilience and functionality of these buoys. Such buoys can convert ocean motions into electrical energy, demonstrating an application of renewable energy technologies in maritime settings.
Regarding the accumulation of marine organisms on buoys, it is not uncommon for them to become fouled by various species, which can impact their performance and necessitate maintenance. The scenario described in which a buoy became fouled with a tropical assemblage before acquiring a circular band of blue mussels is an example of the ecological interactions marine buoys can have.