Don Krock Bio-rational Horticulture

Cleveland Ohio, April 29, 2000 - Don Krock of the Cleveland Zoo Aquatics department presented the "Bio-rational" method of horticulture being used to clean up some of the aquatic displays at the Cleveland Zoo. The Bio-rational method of horticulture promotes more ecological management of the aquatic environments around the Cleveland Zoo.

Bio-rational horticulture also involves the use of beneficial and detrimental insects.

Don first discussed the dump and fill method used to maintain the camel pool. Dump and fill method of cleaning wasted 7000 gallons of water with every weekly cleaning of the camel pool. Don described the filtering vessels and listed the different types of aquatic and semi-aquatic plants used to create a bio-filter for the camel pool. With the plant filter in place, the camel pool now is cleaned twice a year resulting in annual water savings of 84,000 gallons.

Edge of the camel pond

The camel pond filter

The waterfall lake project was the next successful project Don discussed. Filamentous and planktonic algae were overrunning the lake. The goal was to biologically reduce the algae without the addition of chemicals. Don then listed all aquatic and semi aquatic plants used to compete with the algae for nutrients. The water clarity improved to point that the bottom of the lake can be seen in depths of 3-4 feet.

After the lecture Don escorted us to the camel pond to see the plant filter, the wolf exhibit to discuss the filtering methodology employed, and the fall lake to see the improved water quality. The availability of zoo tours and zoo staff with expertise and experiences like Don's were big enhancements to the convention agenda.

The pond in the wolf exhibit