Toxic Bloom
Prevent the invasion of the toxic Gymnodinium catenatum and save your bivalve cultures! Shoot some red seaweed to use their allelopathic effects.
Embedded Files
Gymnodinium catenatum colonies of various sizes (usually in multiples of two or four) fixed with Lugol and viewed under a microscope
The G. catenatum issue
Harmful algal blooms (HABs) can cause major issues, especially in aquaculture. The dinoflagellate Gymnodinium catenatum is one such species - it produces paralytic shellfish toxins and can accumulate in filter feeders such as oysters or mussels, making them inedible. Therefore, preventing G. catenatum blooms is of great importance.
A possible solution
One way of doing this is to co-cultivate seaweeds with allelopathic effects. Allelopathy is an ecological phenomenon where one species or organism releases chemicals that negatively affects another, for example by preventing its growth or reproduction. Some seaweeds have the potential of doing so, and in this study, we tested the allelopathic effect of two species on G. catenatum cultures.
Allelopathy experiment in co-cultures
In the experiment, we tested the effect of seaweed species (Ulva spp./Asparagopsis armata), form (fresh/extract), and concentration (high/low) on the survival of G. catenatum over the span of a week. We counted colony sizes and density every other day using a microscope and a Neubauer chamber. After analyzing the data, we found that both species seemed to have the potential to decrease G. catenatum survival - very exciting! This was a first step towards understanding the effect of seaweeds on G. catenatum, and future studies might focus on investigating the impact on e.g. oyster larvae or water chemistry.
Asparagopsis armata
Ulva spp.
Experimental setup; here, the "fresh" seaweed treatment is shown
Page updated
Report abuse