in this video we're looking at trophic levels which are basically just the different levels within a food chain so in this one here the grass would be trophic level one the rabbit would be traffic level two the snake is trophic level three and the hawk is traffic level four the first trophic level is always a producer like a plant or an algae and we call them producers because they're able to use photosynthesis to produce their own food using energy from the sunlight and this is where all the energy in the entire food chain comes from the second terrific level is made up of primary consumers which basically means first consumers because these are the first organisms in the food chain that consume other organisms and they can also be called herbivores because they only eat plants and algae the organisms in the third trophic level are known as secondary consumers because they're the second level of consumers in the chain and they're also known as carnivores because they eat other animals from this point onwards the pattern just keeps repeating with organisms of the fourth trophic level known as tertiary consumers because tertiary means third and again they'll also be known as carnivores now different food chains in different ecosystems will have different numbers of trophic levels but you usually won't get any more than four or five this is because every time you go up a trophic level some of the energy gets lost and so there's not enough energy to sustain organisms in much higher trophic levels the general rule is that only about 10 percent of the energy that's in each trophic level actually gets passed on to the organisms in the next level so if we started with 1 000 joules worth of energy in trophic level 1 that would be reduced to 100 joules in terrific level 2 then 10 joules in trophic level 3 and only a single joule biotrophic level 4. regardless of how many levels there are though the carnivores at the very top of the chain who don't have any predators are known as apex predators one group of organisms that don't fit neatly into this pattern are omnivores like bears because they eat both producers and other animals in general we place omnivores in traffic level 3 because they eat primary consumers however because they also eat producers it's not really a perfect fit the other groups we need to mention are decomposers and detroit divorce these are organisms like bacteria fungi and some small animals like worms what they all have in common is that they help to decompose the dead plant and animal matter in the environment this allows them to recycle nutrients from animals and plants back into the ground which can then be used again by producers anyways that's everything for this video so if you found it useful then please do give us a like and subscribe and cheers for watching