Black Skimmers Again Showing Signs of Sepsis

On July 21st and 22nd, beach stewards and beach walkers suddenly started seeing limping chicks at the black skimmer colony on Sand Dollar Island. The very young chicks showed visible swollen joints. The weekend before, I was at the colony but was too busy admiring the downy chicks running by the surf.

According to one of the volunteers, if you scan the colony closely, you could also see 10 to 15 carcasses scattered about and all were fledgling sized black skimmers. During my previous visit, many black skimmers were bringing in fish to feed the young and many chicks were dangling fish with their beaks.

Though there seemed to be plenty of food, observers also noticed many chicks were very thin. It was a heartbreaking scene to take in. Volunteers brought several sick and dying chicks to the Conservancy’s von Arx Wildlife Hospital.

New this year – and very disturbing, is the presence of a banded black skimmer adult, B68, who has visited the Sand Dollar Island nesting colony for several years. This week, B68 was sighted with swollen joints and limping badly. When he tried to fly, he could not even pull up his legs.

Last year, no adult was reported with swollen joints.

In 2020, the black skimmer nesting season was cut short due to a deadly illness in the chick colony. Early in the summer of 2020, Adam DiNuovo, a seabird biologist for Audubon, Florida, and the lead researcher of the Black Skimmers in Marco Island, started seeing birds that were showing swollen ankles and digits (feet).

According to DiNuovo, two thirds of the chicks that hatched on Marco Island last year were lost.  The necropsy showed septic arthritis on the joints.  According to DiNuovo, “when you see this in birds, it is coming from sewage, and it is coming from human sewage, and we don’t know where. The only way to determine if it is human borne is to do genetic testing on the bacteria.” He also suggested that the County and City should ramp up water quality testing in different locations. 

Having studied the black skimmers extensively, DiNuovo further added that “black skimmers fly several miles to feed. Somewhere, they are running into something, and it caused illness to the young chicks at the colony.” He urged the stakeholders to “find that problem fast and isolate it.”

On December 4, 2020, Florida Fish and Wildlife (FWC) named the five bacteria that caused the unusually high mortality of black skimmer chicks on Sand Dollar Island. FWC provided the final diagnosis of bacterial dermatitis, tendinitis, and osteomyelitis with multiple bacteria isolated: Enterococcus faecalis, Staphylococcus aureus, Serratia marcescens, Escherichia coli and Pseudomonas aeruginosa.

While the tests confirmed the cause of the death of the chicks, the source of the pathogens is presently unknown. In short, they did not know how the birds became infected and where these bacteria came from. FWC did not find out the true origin of the bacteria that caused the infection and death of the chicks.

DiNuovo then stated that this is not something that is spread from bird to bird – it is either in the water that the birds are standing in, or it is coming back in the food they are eating.

You can only fix the problem if you know where it is coming from!  Here we are a year later asking the same questions. Nothing was done with the information from 2020; no additional water quality testing was done by any regulatory agency and for the 2021 nesting season, it looks like it will be a second year of another chick die offs at Sand Dollar Island.

A year later, we are again asking the same questions. What did FWC do with the information from 2020? Will Florida Department of Environmental Protection (FDEP) have to wait another year for another episode to do something about it?

On July 22, 2021, according to Marianne Korosy, Director of Bird Conservation at Audubon, Florida, "Audubon is actively monitoring the situation and pushing FWC and FDEP to move their timeline forward to test the water in this area to determine the cause of the potential sepsis. More than 100 state listed Black Skimmer chicks died of septic infections last year; this year chicks appear to be dying from sepsis again. Florida has perennial problems with influxes of nutrients and sewage entering our waterways and wreaking havoc on both wildlife and human health.”