This lesson explains the food chain of a dolphin. Here, we’ll learn about what a food chain is and about different dolphin species.
We will also study examples of food chains for different species of dolphins.
Definition of a Food Chain
A friendly school of dolphins swim near your boat as you sail out for a day on vacation. They frolic near you, communicating with clicks and whistles, like the spinner dolphins shown here in Hawaii. The dolphins swim with you for a while, then drift away in search of food. But what are the dolphins looking for? What do they eat? What does their prey eat? These are the questions we will answer today!To start, we need to think about how food moves from the plants, all the way up to dolphins. The way we will do this is a diagram called a food chain.
Bottlenose dolphins eat larger fish, such as tuna and mackerel. They also eat crustaceans and, if living in open oceans, squid. Tuna and mackerel eat smaller fish, such as coastal flying fish in the Pacific Ocean.
These smaller fish in turn eat producers, such as small organisms called phytoplankton. Phytoplankton are microscopic organisms that live by the millions in all oceans. They form the base of food webs by making their own food.
The dolphins are a tertiary consumer in this food chain as well, since they eat secondary consumers: the tuna and mackerel.
Amazon River Dolphin Food Chain
The Amazon River dolphin is one of very few freshwater dolphin species. It lives exclusively in the Amazon River in the rainforest. The Amazon River dolphin is a secondary, and sometimes tertiary predator. It feeds on many different species of fish, particularly larger fish, like catfish, crustaceans, and even piranhas (large flesh eating fish known to attack humans). Catfish feed on other types of fish, making them a secondary consumer.
The smaller fish catfish eat are primary consumers, eating aquatic plants and small, green bacteria that make their own food, known as cyanobacteria.
Threats to Dolphins
The dolphins are tertiary predators, making them extremely important for regulating the food chain. They keep the populations of the secondary and primary consumers in check. If the dolphin populations were to continue decreasing, primary and secondary consumer populations would grow out of control, consuming all the producers.
Without producers, a population will crash, destroying the entire ecosystem.Currently, the main threats to dolphins are pollution, illegal fishing, and destruction of habitat, such as in the Amazon River. Dolphins are attracted to fishing nets, most likely because of the high concentration of prey in them.
The dolphins get tangled in the nets and suffocate or starve to death. Responsible fishing and conservation efforts are key to preserving these species.
In summary, a food chain shows a linear transfer of energy from one species to the next, while a food web involves many food chains that are connected. Producers are the base of the food chain and make their own food. Primary consumers eat producers and secondary consumers eat the primary consumers.
Tertiary consumers, like dolphins, are an important part of the food chain and keep the other species in balance.There are over 40 species of dolphins, all of which are aquatic mammals. The bottlenose dolphin lives in tropical salt water environments and eats secondary consumers like tuna.
Tuna eats primary consumers, like smaller fish, which eat phytoplankton (the producers). The Amazon River dolphin lives only in the freshwaters of the Amazon River. It eats carnivorous fish such as catfish and piranhas. These fish eat smaller fish, which eat the producers (cyanobacteria and aquatic plants).
Dolphins are important to the ecosystem, but illegal hunting, pollution, fishing nets, and destruction of their habitat threaten their species.