Healthy Mud

Conners Emerson 4/22 7th Grade Class B



When our class was out observing the eelgrass tank, a question popped into my mind. Can the mud effect the growth and/or heath of the eelgrass? And what sorts of things can we alter in the tank to make the mud healthier, therefor making the eelgrass healthier?

One thought on “Healthy Mud”

  1. Great Question! The mud absolutely has an affect on eelgrass. First of all the mud could be polluted, and pollution lasts a lot longer in mud than in the water column. At the Fore river in Portland, there were healthy eelgrass beds reported by some residents in the past, but they are all gone now. This may be because of runoff from all the development in the watershed adding nutrients to the water which feeds algae and blocks light, but also because there were two oil spills that affected the outlet of the river in the past 31 years. Eelgrass is not growing in this polluted mud and the estuary is no longer serving as a nursery and energy is not being transferred up the food chain.

    Another problem that can occur with the mud is that it could be LACKING in nutrients. The mud may have too little nitrogen, phosphorus, or iron for the plants to grow. Some have suggested that this is why eelgrass likes to grow near the outflow of rivers, because it does need some nutrients that is carried to the ocean in freshwater. CEHL has been doing studies on the effects of adding fertilizer to the mud. We added blocks of cement and nutrients in the mud under grids of eelgrass we put down at Barry Cove. We had to get permits for this, and test the method in a small area. The results last summer showed that the eelgrass that had fertilizer did grow taller, and that there were no harmful algal blooms because the fertilizer didn’t rise into the water column, it stayed in the mud. We’ll be testing this method more this summer!

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