Can allelopathy succesfully be used against algal blooms?

Question

Algal blooms caused by man (harmful algal blooms) are a major ecological problem. An excessive amount of algae causes hypoxia and logically, most marine wildlife can't be sustained in hypoxic conditions.

Can't we use allelopathic plants to reduce the amount of algae significantly?

Answer 1

This has been tried and it sorta works.

Algae in general seems to be inhibited by rotting barley straw in the water.
There is also an observation (not universally accepted) that many plants in the water do not have as much algae. This post is from April 2011, so it seems pretty current.

Answer 2

Here is a good review titled: Use of allelopathy of aquatic macrophytes for algal-bloom control.

Hu and Hung talked about Macrophyte species which have allelopathy effects on Algal-bloom. This paper discussed the development and potential application of allelopathy of aquatic plants on algae, including the reported aquatic macrophytes having allelopathy on algae, their allelochemicals and potential modes of action on algae, possible ways for application and the prospect of using aquatic macrophytes to control algal bloom. Plants which you want to use for allelopathy effects on algal bloom, must of course be marine. But sometimes allelopathic agents of terresterial plants can be extracted and use for this purpose more commercial than marine planting.