Many golf courses have experience with two primary algae types that are known to haunt many lakes, pond, water gardens, koi golf ponds and dugouts. There are string algae, also known as filamentous algae, angel hair algae, or horse tail algae which appear as wispy thin green silken hairs that can form thick floating mats and drift and clog along the edges of golf ponds especially against rocky shoreline structure like rock walls or bridges. Then there are the varieties of plankton and phytoplankton algae that cause green golf course pond water, either a pale green that reduces clarity and forms golf course pond scum on rocks, or a thick pea soup, sometimes an oily-looking layer of thick almost fluorescent green that looks utterly sickening.
Of course there are hundreds of algae species that exist in nature and while some of them are the bane of golf course pond builders they are all a natural occurrence that propagates when certain conditions (combinations of temperature, sunlight and nutrients) are right.
As with all things in nature there is much that can deciphered by understanding the nature of things. A sudden algae bloom can be a clue to a sudden imbalance in the golf course pond stemming from an influx of nutrients entering the water from lawn fertilizers, a ruptured septic field, or even goose droppings entering the pond! Whatever the cause, it is first necessary to identify the algae and then determine what are the natural conditions and specific circumstances that cause algae to become invasive and troublesome.
The string, filamentous algae that is like slowly drifting hairs is often found in stagnant areas of a golf course pond like around the edges where circulation doesn't occur. Golf ponds with exposed rock shorelines are notorious for becoming warm due to direct sunlight heating the stones which transfer heat to the water. When these stagnant areas become warm and when nutrients are available a slow formation of hair like algae will begin to farm and stick like glue to stones.
Because golf courses must use fertilizers in most cases to keep the grass green and thick there are often issues in the water hazards and irrigation ponds with any golf course.