NOAA Games arrow Quest to Nest arrow Field Guide - Food Chain

The Food Chain: Loggerhead Prey and Predators

What is a Food Chain? Food chains show how nutrients and food energy move through producers and consumers. 

For this game, the loggerhead food chain consists of the following plants and animals:

Phytoplankton/Zooplankton (Plankton), Clams, Whelks, Turtles, and Sharks. 

See the next slides for each part of the food chain.  

  • Plankton Image
  • Clam Image
  • Whelk Image
  • Loggerhead Turtle Image
  • Shark Image

Food Chain: Plankton

Plankton cartoon image

Plankton include microscopic plant and animal organisms that float or drift in great numbers in the ocean. Plankton are the start of most oceanic food chains.

There are many species of plankton and each has a characteristic shape. Plankton may be phytoplankton (plant-like organisms - producers) or zooplankton (animal-like organisms - consumers).

Loggerhead turtles eat plankton when they are very young and small juveniles. Clams also eat plankton.


Food Chain: Clams

Clam Image

There are many species of clams, all of which may be eaten by the whelks, turtles, or sharks in this food chain. Marine clam species live buried in sand or mud and they feed on plankton (both phytoplankton and zooplankton) by filter feeding.

The oceanic surf clam pictured below is a bivalve clam. The clam's shell consists of two valves (sides) that are connected by a hinge joint.

Fun Fact: The oceanic surf clam is the largest clam of the U.S. east coast. It sometimes reaches a shell length of more than eight inches. That’s about the length of an unsharpened pencil.


Food Chain: Whelk

Whelk Image

Whelks are a type of gastropod that live within their own shell. They are found all along the shallow waters of the U.S. Atlantic and Gulf Coast shorelines.

Whelks have a sculptured spiral shell that coils either to the right- or left-hand side and then tapers to a point at one end. A common species of whelk in the U.S. is the lightning whelk or sea snail.

Whelks feed on several bivalve species, including clams.

In coastal U.S. waters whelks are often harvested and they are also eaten by loggerhead turtles.


Food Chain: Loggerheads

Loggerhead Image

Loggerhead turtle hatchlings feed on small animals living in the sea. Juveniles and adults eat creatures such as whelks, horseshoe crabs, and sea urchins. Their powerful jaws are designed to crush their prey.

Loggerheads are eaten by many different species. Snakes, birds, and small carnivores feed on turtle eggs and hatchlings on land. Hatchlings are also eaten by ghost crabs, sea birds, raccoons, and other animals on the beach.

Birds and reef fish eat hatchlings in the water, but the turtles soon become too big for most of these predators.

Sharks prey on loggerhead turtles throughout their lives. Turtle flippers are especially vulnerable to shark attack because turtles cannot retract them into their shells.


Food Chain: Tiger Shark

Shark Image

The tiger shark is named for the tiger-like stripes on the body. Like most sharks, it has an excellent sense of sight and smell.

Their curved teeth are heavily serrated on both sides which allows them to crack the shells of sea turtles and clams.

Tiger sharks have a reputation for eating almost any animal. They often prey upon small fish and sharks, as well as turtles. Sharks are generally considered the top predators in the marine environment. Tiger sharks are solitary hunters that feed primarily at night.

Tiger sharks are about 2 feet long at birth, and grow to a length of 10-15 feet.