ELI5: Explain Like I'm 5

Aquatic-terrestrial subsidies

Okay kiddo, do you know what an ‘aquatic’ environment is? It’s where things like fish, turtles, and frogs live in the water. And do you know what a ‘terrestrial’ environment is? It’s where things like trees, grass, and animals like squirrels live on land. So, ‘aquatic-terrestrial subsidies’ are when things from the water help the things on land, and vice versa.

For example, when fish swim in the water, they eat little bugs in the water called ‘aquatic insects’. Then, when those fish swim back to the riverbank and eventually die, their bodies become food for animals like birds or bears. This is an example of a subsidy from the aquatic environment to the terrestrial environment - the fish are helping the animals on the land get food.

On the other hand, animals on the land can also help the creatures in the water. Let’s say a raccoon is walking around near a river, and finds some tasty crayfish to eat. The raccoon might eat some of the crayfish, but then leave some of them on the riverbank. Those crayfish that are left behind in the water become food for fish, which is another example of a subsidy.

So overall, aquatic-terrestrial subsidies are when the creatures in the water and the creatures on the land are connected and helping each other out. It’s like a big cycle of life, where everything is connected and relying on each other to survive.