A record number of Florida manatees were killed by boat strikes and a near-record number of overall manatee deaths were reported in 2018.

A total of 804 manatees died in Florida waters last year, close to the record 830 set in 2013, according to data from the state Fish and Wildlife Conservation Commission.

Boats killed 119 manatees in 2018, breaking the record of 106 set in 2016 and tied in 2017. The commission started keeping manatee mortality records in the 1970s.

"Nobody wants to kill a manatee," said Jaclyn Lopez, Florida director at the Center for Biological Diversity. "The record points out the need to better mark slow-speed manatee zones on our waterways and better enforcement of speed limits in those zones."

About 15 percent of manatee deaths in the state last year were caused by boat strikes, according to FWC data.

More: Manatee deaths from boat strikes in 2017 ties record set in 2016

On the Treasure Coast, boat strikes caused eight of the total 37 manatee deaths last year. In Brevard County, 14 manatees, out of 116 reported dead, were killed by boats.

Forty-five of Brevard's dead manatees were dependent calves less than about 5 feet long that died around the time of birth from causes determined not to be human-related; the FWC refers to them as "perinatal" deaths.

Red tide, a naturally occurring but highly toxic algae, killed 91 manatees and is suspected of killing 118 more. All but one of those deaths were on Florida's Gulf Coast. Authorities suspect red tide killed a 249-pound male manatee found dead Nov. 15 in the Indian River Lagoon near Stuart.

Red tide killed hundreds of thousands, perhaps millions, of fish along the Treasure Coast and Brevard County from late September to early November. But the algae was gone from the area as of Nov. 8, according to FWC data.

More: Toxic red tide algae bloom finally gone from Treasure Coast

Sea cow count down

An aerial survey in early January 2018 counted 6,131 manatees in the state's waters. That's down from a record 6,620 sea cows tallied during the 2017 survey. Counts have exceeded 6,000 since 2015.

More:Aerial survey finds fewer manatees in Florida waters

Fifteen observers from 10 organizations counted 3,731 manatees on Florida's East Coast and 2,400 on the West Coast.

Surveys are conducted during the coldest weather of the year (January through March), when manatees move to warm-water sites such as natural springs, deep canals and thermal discharges from power and industrial plants.

Column:Feds say manatees no longer endangered

Manatees on the march

Manatees are most likely to be seen this time of year because many are migrating south for the winter. Look for manatees traveling in the lagoon and nearshore ocean waters.

They don't wander too far out in the ocean because sunlight can't penetrate deep water to grow the sea grass they eat.

Because boat strikes are a preventable cause of manatee deaths, powerboats are required by law to stay at least 50 feet from sea cows.

Save the Manatees

Manatees are endangered and protected by Florida and federal laws. Here are some tips from the Florida Fish and Wildlife Conservation Commission for boaters and manatee watchers:

Obey posted speed zone signs while in areas known to be used by manatees.

Wear polarized sunglasses to reduce glare on the surface of the water so you can see manatees more easily.

Look for manatee "footprints," swirls or flat spots on the water created by a manatee’s tail.

Stay in deep-water channels whenever possible.

Avoid boating over sea grass beds and shallow areas where manatees are often found. Keep powerboats at least 50 feet away from manatees.

Don’t throw monofilament line, hooks or any other litter in the water; ingesting or getting entangled in debris can be fatal to manatees and other wildlife.

Don't feed or give freshwater to manatees.

Report dead or injured manatees at 888-404-3922.

Source: Florida Fish and Wildlife Conservation Commission

By the numbers

Causes of manatee deaths on the Treasure Coast and Brevard County in 2018:

INDIAN RIVER COUNTY

Boat strike: 3

Perinatal: 3

Cold: 0

Undetermined: 5

Other: 1

Total: 12

MARTIN COUNTY

Boat strike: 3

Perinatal: 1

Cold: 4

Undetermined: 5

Other: 3

Total: 16

ST. LUCIE COUNTY

Boat strike: 2

Perinatal: 1

Cold: 0

Undetermined: 6

Other: 0

Total: 9

BREVARD COUNTY

Boat strike: 14

Perinatal: 45

Cold: 21

Undetermined: 24

Other: 12

Total: 116

Source: Florida Fish and Wildlife Conservation Commission