Deck 12: Estuaries: Where Rivers Meet Seas

Question 1

A proposal is made to deepen the entrance and main channel of an estuary. What do you think will happen to the salt marshes that surround the channel? What do you predict will happen to the primary production of the estuary as a whole?

Answer 1

Estuaries are special regions where the river and seawater mix together. The species of organisms available in this area are quite unique. It is also one of the most productive areas. Since it is difficult for the organisms living in freshwater to survive in seawater, therefore the number of species present here are lesser than those present on the rocky shores.
If the entrance and main channel of the estuary are deepened following human action, it would drastically alter the effect of tide on the estuary. The waves would easily penetrate the estuary, thus allowing the ocean water to mix with the estuary. It would also increase the sedimentation and thus an increase in the salinity of the area. The increased tidal strength and salt concentration would reduce the number of species sustaining there. In addition, the primary production of the area would also drastically reduce.

Question 2

Some of the organic material manufactured in estuarine communities is exported to other ecosystems. What type of ecosystems receives this material? How is this material transported?

Answer 2

Estuaries are special regions where the river and seawater mix together. The species of organisms available in this area are quite unique. It is also one of the most productive areas. Since it is difficult for the organisms living in freshwater to survive in seawater, therefore the number of species present here are lesser than those present on the rocky shores.
The organic matter produced in the estuaries benefits the coastal as well as the open water ecosystem. The change in tidal waves helps in the transportation of nutrients between the estuaries and oceans. These nutrients are transported as detritus and help in nourishing the kelps and corals. In addition, the organisms dwelling and breeding in the estuaries return to the oceans during tidal changes, thus increasing the species distribution in the area.