Biologists are posting hundreds of signs on the seawalls of the Indian River Lagoon in an effort to save dolphins. The placards caution visitors not to feed the dolphins or discard fishing gear in the lagoon.

The placards, which have been used in other coastal areas, have proven effective.

“We’re using them on seawalls and fishing piers where the fishermen set up all their gear and they’re sitting there, waiting for a fish, and they’re looking down and the massage is right there," said Cheryl Munday, Marine Mammal Outreach Specialist.

Seven dolphins have been killed by fishing lines and hooks so far this year, a surge from recent years. Fishing lines can entangle dolphins or cause them to choke on their food. Biologists believe the increase in deaths is caused my mother dolphins teaching their calves to take fish off fishing lines and approach humans for food.