Investigating Lodi Lake’s creepy crawlies
Needham Elementary students learn about local landmark’s ecosystem
With sifts in their hands, students from Needham Elementary School were on the search for interesting creatures picked up in samples from Lodi Lake and the Mokelumne River. Others were peeking into microscopes and using magnifying glasses to spot the tiniest signs of life in the water.
“We’re looking for bugs of different kinds,” said Angel Salazar, a fifth grader. “We found worms.”
A few weeks ago, small mesh bags filled with rocks and leaves were dropped into Lodi’s waterways to attract invertebrates to munch on and hide in the leaves. These leaf packs were lifted out of the water and studied outside by these scientists.
Groups of students were tasked with sifting the invertebrates out of the leaves and water buckets to place in petri dishes for easy identification.
Some of these animals included crayfish, fly larvae, worms of various kinds, leeches and snails. They were looking for a diversity of small — and, in some cases, microscopic — animals to show the biological health of Lodi’s waterways.
“There are generalists that can live almost anywhere, and then there are specialists which are tied to clean water quality,” said Donnie Ratcliff, assistant program manager with the U.S. Fish and Wildlife Service.
Black fly larvae is a good example of an animal that can survive in murky waters, while caddisfly larvae — relatives of the butterfly that spin their own silk — require clean running water. In the past, insects were used to test the quality of water that left sewage treatment plants, but currently chemical testing is used instead, Ratcliff said.
Experts from U.S. Fish and Wildlife and Lodi Lake Docents and other volunteers guided students in identifying them with a sheet organizing the animals by numbers of legs, if they had wings or other defining characteristics. They also brought some samples from upstream so that they’d get a variety of creatures to find.
Students tallied their findings and also got the chance to handle some of the creatures. The sight of volunteers placing a stone fly into students’ hands led to some brief screams, but many were excited to hold it.
“It feels weird, like it sticks to your hands,” said Jairo Carrillo, a fifth grader who was seeing the insect in person for the first time.
Students were able to experience this hands on day of science through a grant from the GOT Kids Foundation. The class is planning to make a trip out to the University of California, Davis to visit the insect museum, according to their teacher, Martina Ruiz.
“It’s the first time putting it together and we’re privileged to be a part of this,” she said.