Darienne Purtz pulls a wheeled cart out of the storage shed, hundreds up her clipboard, boots, and different gear, and rolls it onto the boardwalk towards this week’s pattern web site. As a analysis affiliate for Audubon’s Corkscrew Swamp Sanctuary, Purtz sometimes conducts her work within the sanctuary backcountry, however at present, she threads her means round curious guests, her cart bumping over the boards. Purtz is pleased for the chance to have interaction, and most guests categorical appreciation for the work underway as a part of the Sanctuary’s mission to collaboratively defend birds, different wildlife, and other people from the unintended penalties of burgeoning improvement and related human exercise close by.
Aquatic surveying program
Audubon workers monitor populations of small animals that dwell within the water, together with fish, amphibians, and bugs, as a result of they function indicators of a wholesome wetland and make up the prey base for birds and different animals.
“We’ve got survey websites in 5 completely different areas of the Sanctuary, the place we acquire information 3 times a yr,” provides Purtz. 4 websites are related to wetland restoration actions, and the fifth one is alongside the CLASS loop of the boardwalk, which is usually solely accessed throughout teaching programs.
At every examine web site, Purtz deploys six wire mesh minnow traps at water depths of at the very least 20 inches. Roughly twenty-four hours later, she checks the traps and collects the captured animals to deliver them again to the lab, the place they’re recognized, sexed (for some species), and measured.
Animals that dwell within the water are monitored within the late-wet season (Oct-Nov), the early-dry season (Dec), and the mid-dry season (Jan-Feb). The swamp adjustments dramatically over the course of a yr, and these three sampling occasions enable biologists to see how animals reply to these adjustments.
“Minnow trapping solely works if there’s sufficient water for fish and different species to maneuver round, and if that water is heat sufficient that they’re energetic,” says Purtz.
Generally caught fish species embrace flagfish, golden topminnow, and Jap mosquitofish, however the traps additionally seize crayfish, amphibians (grownup and larval), and aquatic bugs, reminiscent of predaceous diving beetles.
Right this moment’s catch
Upon arriving on the CLASS loop web site, Purtz pulls out her clipboard and pen to file the time the traps are pulled and the water depth. She opens the primary entice and readies her ruler. Amidst the squirming fish, she is happy to identify a peninsula newt, Notophthalmus viridescens piaropicola. These amphibians depend on calm, recent waters with loads of vegetation the place they conceal from the time they hatch as larvae by means of their grownup type. Curiously, this species is unpalatable to many fish, however crayfish, turtles, and wading birds can eat them. Purtz additionally recorded a number of slough crayfish within the traps the place newts had been caught.
As soon as all entice contents are eliminated and recorded, Purtz hundreds the empty traps on her cart and rolls every little thing again to the lab, the place she is going to course of the samples and start getting into the info.
Why that is necessary
Aquatic fauna sampling is barely one of many some ways Audubon workers preserve tabs on wildlife populations within the Sanctuary to assist the conservation and restoration of pure ecosystems all through the Western Everglades.
“The presence and absence of some species affirm satisfactory water ranges and water high quality situations,” says Purtz, who explains that the species caught and the numbers of people range relying on season.
Fish, insect, amphibian, and reptile information inform biologists how the ecosystem responds to wetland water ranges and supply perception into the meals out there for predators, like wading birds, alligators, and otters. These prey species are key indicators, and information collected from a wide range of surveys of animals within the water and on land, mixed with vegetation surveys, allow the analysis staff to attach the dots between the annual rise and fall of water ranges and the well being of the whole ecosystem.
