PRESERVING PARADISE

Low dissolved oxygen, fish kill alert for Sanibel lakes

T h e S a n i b e l - C a p t i v a C o n s e r v a t i o n F o u n d a t i o n reported that the storm surge from Hurricane Ian drastically changed the characteristics of most freshwater lakes and ponds on Sanibel

“As a result, current conditions add up to an increased potential for fish kills in Sanibel lakes this summer, especially following cloudy days,” Marine Lab research associate Mark Thompson said

He explained the following:

∫ Freshwater was immediately displaced by the storm surge and saltwater from the Gulf of Mexico took its place

∫ Freshwater fish that were resident in the lakes and ponds died immediately or over the next few months

∫ The storm surge also introduced estuarine and marine fishes within some lakes and ponds The marine fish are accustomed to tidal exchange and water with high levels of dissolved oxygen

∫ Deeper larger lakes on Sanibel, such as those in The Dunes, East and West Rocks, Lake Murex, The Sanctuary and Beachview Estates, will be very slow to change back to freshwater possibly taking years

∫ Most of the salty lakes are not experiencing blooms of marine and estuarine microorganisms, known as phytoplankton or algae

∫ The phytoplankton produce oxygen during sunny days due to photosynthesis and add oxygen into the water

∫ During the nighttime, phytoplankton use oxygen out of the water, and oxygen levels drop Cloudy days, like the weekend of June 16-18, disrupt the ability of phytoplankton to photosynthesize, and they are not able to produce oxygen and add it to the water. However, they continue to use oxygen from the water to respire, along with fish and other lake inhabitants

∫ Low levels of dissolved oxygen in Sanibel lakes result from the combination of the above events Marine fish are not adapted to low dissolved oxygen levels and dire during the low oxygen events brought on by cloudy days

The SCCF reported there is an increased potential for fish kills on cloudy days in lakes post-Ian

“Over the course of years, these lakes which are now marine waterbodies will become more fresh and marine fish like mullet, snook, tarpon will either adapt while others such as shad, herring, redfish, porgies will die off,” Thompson said “Meanwhile, freshwater fish such as non-native cichlids, bass and sunfish will begin to reappear ”

Season’s first sea turtle hatchings on islands

The Sanibel-Captiva Conservation Foundation reported that the first sea turtle hatchlings of the season have emerged on Sanibel and Captiva The first nest hatched on June 21, and several other nests had hatched as of June 28, with 387 hatchlings starting their journey into the Gulf of Mexico.

“Our volunteers have been incredibly busy this year, and we are so grateful for the long hours they're spending on the beach to protect our sea turtles,” sea turtle biologist Jack Brzoza said

The SCCF reported that the islands are on track for a record-breaking nesting season, with more than 855 nests on Sanibel and Captiva as of June 28, including 18 green sea turtle nests

In addition, the SCCF reported that it recently asked the community to help replenish its supply of towels, which help cover buckets that hold and protect hatchlings

“We've received an outpour of responses to this request and have enough towels for the foreseeable future during this busy season,” he said “Thank you to those who donated these crucial supplies ”

Sea tur tle rescue

On June 27, the SCCF reported that an adult loggerhead sea turtle was rescued off Sanibel the prior week after being found swimming sideways, struggling to come up for air Some crew members aboard a boat spotted it in distress and were able to bring her to the beach, where SCCF staff dove into the water to help retrieve the turtle

“With the help of other crew members on the beach, the sea turtle was safely moved to a SCCF vehicle so we could transport her to a rehab center where she is receiving expert care,” Coastal Wildlife Director Kelly Sloan said

The AshBritt boat crew, a contractor working for the Florida Division of Emergency Management, and their local subcontractor RJ Gorman, called the SCCF after seeing the sea turtle hotline on a sign on a turtle nesting

The Sanibel-Captiva Conservation Foundation reported that an adult loggerhead sea turtle was recently rescued off Sanibel after being found swimming sideways, struggling to come up for air site Two SCCF staff quickly came to the beach area to meet the crew, who swam to shore while holding onto the turtle

The SCCF reported that thanks to everyone's assistance, the turtle is in Sarasota under the care of the Mote Marine Lab and Aquarium, where she has been named Artemis Sloan noted that they remain hopeful for a successful recovery

If you find a sick or injured sea turtle, call the SCCF Sea Turtle Hotline at 978-728-3663

For more information about the SCCF's sea turtle prog r a m , v i s i t h t t p s : / / s c c f o r g / w h a t - w e - d o / p r o t e c twildlife/sea-turtle-program/

SCCF shorebird team shares guide to aging chicks

By SANIBEL-CAPTIVA CONSERVATION FOUNDATION

With the arrival of July, shorebird and seabird nesting season is starting to wind down Most of the final renesting attempts will be occurring this month, which means you could be seeing shorebird and seabird chicks soon, if you have not already

On Sanibel and Captiva, we currently have snowy plover and least tern chicks of varying ages In case you see one and wonder how to tell how old that little bird is, we have put together some identifying characteristics by age to help you figure that out.

Least ter n chicks

After hatching, least tern chicks appear sand-colored, speckled, and without visible wings or tails looking very similar to the eggs from which they just hatched page 20