An Amazing Year for Marco Dolphins

As 2022 comes to a close, the study team on board the Dolphin Explorer has recorded some unique and surprising data for this period. Some of the information is “business as usual” for our findings year after year while other data is very unique to the happenings throughout 2022.

The dolphin population that we study is non-migratory. They are coastal bottlenose dolphins which means they stay close to the shorelines or travel the Marco river and surrounding estuaries. They are seen here all year long and some have a travel range of twenty miles, more or less, in this habitat.

By year’s end the team will log nearly four hundred excursions looking for dolphins and the total number of individual dolphin sightings will be approximately 4,700. These sightings will comprise about 120 different dolphins. Naturally, some are seen more than others but all must be seen a minimum of ten times in order to be considered a “resident” dolphin in our survey area. There are about 100 more dolphins that pass through the area, not seen on a regular basis, that we catalog as “transient.”

Eleven new calves were documented during the year with one first time mom in the group. The other ten adult females are experienced mothers, some with multiple offspring. The majority of births on the north end of Marco Island, our primary study area, occur during September, October and November, with just a few calves born a month or two before or after this period.

There was one major exception this year. Adult female MT2 was seen with a calf in May. It is unfortunate, but the calf was stillborn. Our Marine Biologist, James, suggested that that calf appeared to be about seven months old, which puts the birth month at October if MT2 had carried full term. Since the calf was seen it was cataloged and given a name, Lillyfurd.

The other births were very typical, ranging from August to November. One female, Avery, gave birth to her seventh known offspring and it was named Snowflake. The other calves are Lillybet, Venture, Razz, Pitchfork, Taco, Queso, Thimble, Jolley and Gotham. Names are chosen by guests on our excursions when a calf is seen for the first time.

Regarding the rest of the population, on November 23rd we got a call from law enforcement that a dolphin was found in one of the bays and it was deceased. They forwarded a photo of the dorsal fin, the large fin on a dolphin’s back, and we were able to identify that male dolphin as Cam. When we met with authorities at the sight where the dolphin was being extracted, it was very clear that this was our male Cam. There was little sign of external trauma, but a full report will be forthcoming from authorities. Cam’s teeth were worn down to the jaw, which is a sign of old age. Our team watched this big male continue to slow in his movements in the water. More likely than not, old age took its toll on Cam.

One of our other big males, C. U. Jimmie, has not been seen since November of 2021. He was a regular in the north Marco area and he, too, had shown signs of aging. In December of 2021, an adult female named Rangle was found along the shoreline. She had a one-year-old calf by her side and the team was worried about the ability for this youngster to survive with a mom. We found him, Dixon, right where mom was teaching him to feed and there were multiple sightings of him throughout 2022 feeding, and eventually socializing with other younger dolphins.

For the year, the team noted eleven new calves, one which was stillborn, and two adult males that are no longer with us. This is a net increase of eight to our population and we would have to conclude that this was a positive year, overall, for our area dolphins. For the last five years of 2018 to 2022 there have been forty-three births documented and three adults not surviving, as well as six calves not surviving for a net increase of thirty-four dolphins to the area. The coastal dolphin population in our survey area has increased more than 25% in a half decade!

The X factor for the year was Hurricane Ian. Unlike the 2017 Hurricane Irma, this one had an entirely different characteristic. Irma was more of a rain event and less storm surge, although it did cause significant area damage. The surge from Ian was quite a bit higher, as much as eight to nine feet in the Marco Island area and more than fifteen to twenty feet in portions of Lee county.

After Irma, our team was on the water within three days of that event, counting our dolphins and assessing any loss of life. Within a few weeks more than 95% of our dolphins were sighted.

Ian was a different story. After ten weeks, the team has still not seen about 15% of our local dolphins. This does not mean that they did not make it, they have just not returned to the area. It has been a slow process counting our population since Ian, with only a few returning at a time over more than two months. Part of the reason may be the water quality and its slow return to being suitable for our dolphins.

Lee county, where Ian made landfall, had a tremendous amount of debris and bacteria in the water there. The Gulf Stream current moves north to south along our coast so a lot of the mess up there was carried down here. Dolphins are smart and will stay where water quality and a food source are abundant. We expect to see more of our local population returning over time.

You can understand why this is an amazing year for our dolphins. A net increase of eight to our population is great. Eleven new calves in 2022 is more than we have documented in quite some time for a single year. If we can count on experienced females to continue having a new calf every three to four years the number of area residents will continue to grow. The overall health of the general population is great as well. It has indeed been an amazing year!

What will 2023 bring? You will have to stay tuned to Coastal Breeze News, keep up with our website dolphin-study.com and follow us on Facebook The Dolphin Study Marco Island. We will be happy to keep you posted about all of our dolphin happenings. Happy New Year from the Dolphin Explorer team and from our dolphin friends as well!