Journal archives for May 2022

May 30, 2022

Mullet Lake - inland salt flats

Mullet Lake Park borders the St Johns River, and Mullet Lake is an oxbow between Lake Harney and Lake Jesup in northeastern Seminole County.

The park contains extensive salt flats even though the river is freshwater. Here is a map of the aquifer, which shows chloride intrusion extending inland along the St Johns River valley, which contains eastern Seminole County and Mullet Lake. (Seminole County is northeast of Orlando)

I suspect there are salt seeps in this area, which allow for salt-tolerant species to thrive next to a freshwater river. The groundwater chloride concentration according to this figure would be mesohaline (brackish).

I visited the park to check on the Eastern Pygmy-Blues I found there in 2020, and I found six individuals in different parks of the park. Their host plant are pickleweeds (Salicornia), a salt-obligate species. I also found Marl Pennant, a dragonfly that requires alkaline water, and a lot of Needham's Skimmers, which I've found to only occur in coastal, alkaline, or eutrophic waters in Florida. I expect to find Seaside Dragonlet here, but I haven't found them yet. It's interesting to see these coastal species alongside Two-striped Forceptails, a freshwater species. There also are plenty of Salt Marsh Mosquitoes here too - ha!

The highlight for me was finding a couple Brown Wasp Mantidflys (Climaciella brunnea). They are unrelated to mantids, and their mantis-like forelimbs are an example of convergent evolution.

Posted on May 30, 2022 03:47 PM by stevecollins stevecollins | 11 observations | 4 comments | Leave a comment