Adam DiNuovo, a seabird biologist for Audubon, Florida and the lead researcher of Black Skimmers in Marco Island, provided the Beach and Coastal Resources Advisory Committee (BACR) an update on the 2020 season. Every summer since 2017, BACR has supported DiNuovo’s Black Skimmer banding project on Sand Dollar Island during summer nesting season.
Unfortunately, DiNuovo informed BACR that the banding project was cut short because of an illness in the colony. Early in the summer, DiNuovo and shorebird volunteers started seeing birds that were showing swollen ankles and digits (feet).
According to DiNuovo, two-thirds of the chicks that hatched on Marco were lost. “The necropsy showed SEPTIC ARTHRITIS on the joints. In birds, this kind of sepsis goes to the legs of the birds.”
Septic Arthritis: is an infection in the joint fluid and joint tissues and usually reaches the joints through the bloodstream.
Necropsy: is an examination and dissection of a dead body to determine the cause of death or the changes produced by the disease.
The bacteria isolated from the joints were:
- Pseudomonas aeruginosa: a common bacterium that can cause disease in plants and animals including humans.
- Enterococcus faecalis: a bacterium inhabiting the gastrointestinal tracts of humans and other mammals.
- Escherichia coli also known as E. Coli: a coliform bacterium commonly found in the lower intestine of warm-blooded organisms.
In addition, DiNuovo remarked, “when we see this in birds, it is coming from sewage and it is coming from human sewage. The chances of the illness being a wildlife borne illness is slim.”
It is as DiNuovo’s explained, “the birds’ illness I saw this summer was caused by human borne sewage coming from somewhere—but 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 suggests that the County and City should substantially ramp up its water quality testing in different locations—but it could be cost–prohibitive.
According to DiNuovo, Black Skimmers fly several miles to feed. “Somewhere, they were running into something and it caused illness to the young chicks at the colony. There was a lot of rain during the summer and also there are still places where septic tanks are being used. It could be a leaky septic pipe somewhere that nobody knows about. Find that problem fast and isolate it.”
BACR member Tyler asked this question: “To your knowledge, has this been seen anywhere else?” DiNuovo replied that he has been working with bird colonies for the last 20 years, and he has asked his colleagues nationwide who are also managing seabird colonies. “Nobody has ever seen or heard of cases of Septic Arthritis anywhere as reported on the Marco Island Black Skimmer colony.
“To put this in context, the colony in Marco is 250-300 nesting pairs of Black Skimmers. And it looks big while you are out there.” However, some of the colonies that DiNuovo has worked in the past had 250,000 pairs of nesting birds. Even in larger colonies, DiNuovo has not heard of this fatal concentration of septic arthritis.
DiNuovo tried to be reassuring in stating, “septic arthritis is not 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.”
Another question posed to DiNuovo asked if he thought birds must have flown in from somewhere else with the bacteria? According to DiNuovo, “among the chicks that died, none of them are old enough to have flown from other places—all were born on Sand Dollar Island.”
In October, a member of the BACR reached out to FWC for comment and Michelle Kerr, a spokesperson for the agency replied that “they are aware of the sick and dying birds in the colony with swollen joints and legs.”
Black Skimmer chicks in Marco died of a deadly case of septic arthritis, the likes of which have not been reported or recorded anywhere. There are concerns regarding the potential presence of human borne bacteria in waters close to the Black Skimmer colony.
This could repeat itself in 2021 and beyond unless the source is identified and addressed.