Question

lab stations: build a food web
part 1 research: travel around the room and read about 15 different animals in the saltwater marsh ecosystem. jot down notes related to how they obtain energy. you will use these notes to construct a food web that depicts the feeding relationships between the different organisms in this ecosystem on the next page.
red drum (redfish)
stingrays
dolphin
whelks (snails)
sea hawks
ducks
phytoplankton
salt marsh grass
sea snakes
shrimp
oysters
insects
menhaden or mullet
crabs
sharks
energy flow unit

Explanation:

Below are the established energy/feeding relationships for each organism in a saltwater marsh ecosystem, which form the basis of a food web:

1. Producers (base of the web, make their own energy via photosynthesis):

• Phytoplankton: Photosynthetic aquatic microbes
• Salt marsh grass: Photosynthetic marsh plant

1. Primary Consumers (eat producers):

• Whelks (snails): Feed on salt marsh grass/algae
• Oysters: Filter and eat phytoplankton
• Shrimp: Eat phytoplankton and detritus
• Insects: Eat salt marsh grass
• Menhaden or Mullet: Eat phytoplankton
• Crabs: Eat salt marsh grass and detritus

1. Secondary Consumers (eat primary consumers):

• Red Drum (redfish): Eat shrimp, crabs, menhaden/mullet
• Stingrays: Eat crabs, oysters, shrimp
• Sea snakes: Eat fish like menhaden/mullet, shrimp
• Ducks: Eat insects, snails (whelks), and marsh plant material

1. Tertiary/Apex Consumers (top predators, eat secondary consumers):

• Dolphins: Eat red drum, menhaden/mullet, stingrays
• Sea Hawks: Eat ducks, small fish, shrimp
• Sharks: Eat red drum, stingrays, dolphins (occasionally)

Answer:

A saltwater marsh food web structured from these relationships:
Producers: Phytoplankton, Salt marsh grass
↓
Primary Consumers: Whelks, Oysters, Shrimp, Insects, Menhaden/Mullet, Crabs
↓
Secondary Consumers: Red Drum, Stingrays, Sea snakes, Ducks
↓
Apex Consumers: Dolphins, Sea Hawks, Sharks

With specific feeding links:

• Phytoplankton → Oysters, Shrimp, Menhaden/Mullet
• Salt marsh grass → Whelks, Insects, Crabs
• Shrimp → Red Drum, Stingrays, Sea snakes, Sea Hawks
• Crabs → Red Drum, Stingrays
• Menhaden/Mullet → Red Drum, Sea snakes, Dolphins
• Whelks → Ducks
• Insects → Ducks
• Red Drum → Dolphins, Sharks
• Stingrays → Dolphins, Sharks
• Ducks → Sea Hawks