 marine ecosystem, the narratic ecosystem, first the contents the narratic ecosystem productivity of narratic ecosystem and plants and animal life present in the narratic ecosystem. So what's the definition of narratic ecosystem? So narratic ecosystem is actually the ecosystem which is present from intertidal zone or which is present between intertidal zone and the continental shelf. So if we look at it from the intertidal zone the edge of the continental shelf where the continental shelf starts the area that is called the narratic zone. So narratic zone is also called the shallow water zone. So its depth is less than 200 meters its depth is less than 200 meters. So here in this diagram if we look at it from the intertidal zone to the intertidal zone the area where the depth starts 200 meters from the intertidal zone that is actually the narratic zone. Now two very important things here number one is that the sunlight penetrates to 200 meters which means that the narratic zone is present in the narratic zone and ultimately the photosynthesis is possible. Where the narratic system is ending or the narratic zone is ending the depth starts all of a sudden. So this is actually the continental shelf where the depth starts and the deep sea starts. The productivity of the narratic ecosystem if we talk about it, for the narratic ecosystem they are having depth less than 200 meters. 200 meters less depth means that the photosynthesis is possible in the narratic ecosystem. So different types of photosynthesizing plants mainly algae, different types of algae are present there in which the kelps will fall, phytoplanktons will fall, different types of other plants are also there. So different types of plants are present here. Second one, the nutrients from rivers and other outside the water bodies they are bringing the nutrients into the narratic ecosystem. So in the narratic ecosystem, the nutrients are coming from the rivers. Second one, the continental shelf will be the upward movement of the nutrients so ultimately they will come into the narratic ecosystem and get absorbed. So the narratic ecosystem is more productive as compared to the open sea. As compared to the open sea, it is a more productive ecosystem So what type of life is possible in the narratic ecosystem? In the narratic ecosystem, aquatic plants are there so when we talk about aquatic plants, most of the time we have different types of algae. So the algae we are talking about are the kelps, seaweeds, then the sea grasses and different types of phytoplanktons are there. So all these are contributing to the primary productivity of the ecosystem. In animals, if we look at animals, the large number of invertebrates are there. So different types of invertebrates are present here. All the behaviors they are starting from, nematodes, annealids, arthropodes, molluscs, akinoderms, all the invertebrates are reported from the narratic ecosystem. So now if we talk about different types of fishes, mainly small fishes are present in the narratic ecosystem. If the depth is less, then small fishes are inhabiting or living here. For example, if we have important things in small fishes they are the coat, the tuna, herring. So different types of small fishes are there. Interestingly, for small fishes to eat large fishes, they also move to the narratic zone. For small fishes to eat up, to prey, large fishes, they visit the narratic zone, so they also visit the narratic zones. Different types of sharks, different types of whales they also visit the narratic ecosystem.