 marine ecosystems, the intertidal zone, first the contents, the definition of intertidal zones, environmental fluctuations in intertidal zone, and plants and animal life present in intertidal zone. So, what are the intertidal zones are the intertidal we can say it is the ecosystem. So, it extends from splashes zone of ocean to the low tide zone. Simply, we can say that if we are talking about water body, so in a water body that position where the water splashes are coming, waves are coming from there to low tide zone. If we look at it, in oceans, you know there are tides, i.e. because of the moon there are tides. In that, when a tide is high tide, the water level is up and it goes to a particular position. Then, when it goes to low tide, the water level will go back and low tide zone will be where the minimum position is. Now, from low tide to the position where the water waves are going, all the areas that is called the intertidal zone, we will call it intertidal zone, this is the area where water is permanently not present, but for timing is present, for timing is not present. So, this is actually the intertidal zone. So, if we talk about environmental fluctuation here, if we talk about environmental fluctuation here, then this is the harshest environment, as you can say it is the harshest aquatic environment. So, the harshest aquatic environment is the intertidal zone, the harshest reference is that if the impact of the terrestrial environment is directly happening here, like in the day time if the temperature is very high, then ultimately the water here will be warm, when the temperature is high. Similarly, here water is not constant, water is coming, water is going back, so again the water availability is not available all the time, but along all these constraints there is the highest number of animal species present here, if we look here, the richest number of species we will get here, the highest number of species we will get on this position. So, if we look at the environmental constraints, there is the temperature fluctuation, surfing. Surfing is where the foaming is formed, so this is also a problem for aquatic animals. Then the effect of rain is there, erosion is there. Similarly, sedimentation is there, that when rain water comes, it will bring a lot of sediment which will settle down the soil particles, so the animals will be buried in the sediments. This is also the major issue, temperature fluctuation is also the major issue for the intertidal zone life. In all the different types of constraints, if we look here, there is the highest number of plants and animals present in this zone, now from this, why there is the highest number of plants and animals, number one, that nutrients are abundant, in this area we get nutrients or they are abundant because here the terrestrial environment is interacting, because of which the terrestrial environment nutrients are available in this zone. Next we will talk about different types of algae are there, different types of large plants are there, mangroves. If we look at the coastline of mangroves, there are mangroves present, one of them was too much, now they are very reduced, so mangroves are basically here, we get them here. Red algae is there, red algae is sea grasses, different types of grasses that we will get on the intertidal zone. For the animal life, if we look at the animal life, different types of fishes and different types of invertebrates are reported from here, if we look at it as fishes or the motiles like crabs or watertides will come up, then they will come in the intertidal zone, like the water will move backward, they will go back with the water, so in this sense they are coming to the intertidal zone for transit time. There are different types of invertebrates, there are a lot of invertebrates here, and the most of the invertebrates are when the tides will go back, they will go back, they will go back to their homes, they will bury themselves in the sand or mud, so if we have a small amount of intertidal zone soil, then there is a huge number of animals present in that soil, so in the soil we will get a lot of animals, so it means most of the animals in the intertidal zone are burying themselves in the soil. The third option that the animals have is that there are some specific areas where the water for the time being comes and stops, so where the water for the time being comes and stops, stands, then what will happen is that the stack of water that will be made, a storage water, some water will be collected with a rock, there are different types of earth reports, even different types of acino drones are also reported from the water, where the water goes, some places are locked up, the fourth option for the animals in the intertidal zone, the fourth option that the animals have is that when the water is not available, then those are all shelled animals, they close their shell, they close their shells, because of which they go to the drought or to the dryness or to the danger, so it means that the animals have different options. Number one, in the intertidal zone, the animals, they may move back along with the tides, they go back along with the tides, in the main water body, fishes and all those animals, they do this job. Second one, they may bury themselves into the mud, you bury yourself in the mud or sand, those invertebrates do this job. Third one, there are some isolated water, there are some waters that are temporarily stored, these temporarily stored regions, specific water it is having also enriched life, it has both types of insects, earth reports, arachnids, different types, even some types of the acino drones are also there, and the fourth option, they are for molluscs, molluscs shelled, so when water tides are not available, they close their shell and save themselves from the drought conditions.