We battled frigid temperatures as we entered the ice-filled water wearing insulated waders for protection against the elements.
This dramatic introduction sounds like the start of an exciting adventure story in some far-off place, but it actually describes some of the unbelievable conditions right here in Michigan where you can find one of the most fascinating creatures – the common mudpuppy (Necturus maculosus maculosus).
This four-legged, fully aquatic amphibian can be found in rivers, lakes and ponds throughout the midwestern U.S., including the waters of the Detroit River. The Detroit Zoological Society (DZS) is actively engaged in many field conservation projects, including surveying the common mudpuppy around Belle Isle. Our amphibian department has conducted surveys since 2009 as a way to learn more about the overall health and population of the salamanders found in the area. Fieldwork for the project is conducted twice monthly at two different sites, and it is never to be done alone; due to the danger posed by the elements, there must always be two people working on the survey. Depending on the weather conditions, surveys at times are limited to collecting water samples; other times it can involve trapping and processing mudpuppies.
Listed as Least Concern by the International Union of the Conservation of Nature (IUCN), little is known about the true population size of mudpuppies – not just in Michigan but also throughout its entire range. Even though this aquatic salamander has a pair of lungs, it uses blood red, feathery gills located on the sides of its head to gain oxygen from the water. It has a rather flat body and wide head and it uses its tail to move through the water. Mudpuppies prefer to hide under rocks and logs during the day and forage on aquatic insects, crayfish and fish.
Like all amphibians, mudpuppies are valuable indicators of wetland and habitat health. Since water and air move freely in and out of an amphibian’s permeable skin, they will be the first creatures to become sick or even die from the pollutants or toxins found in the habitat, warning us of any impending problems.
Fieldwork and data collection for this project is typically a two-day process. On Day 1, we are in the field collecting water samples and data on the weather, and also setting traps. To capture mudpuppies, we use small collapsible minnow traps that we weigh down to the bottom of the river and bait with frozen smelt. We tie the traps to the shoreline so they won’t be lost in the current of the river. We leave them overnight to allow the mudpuppies plenty of time in their undisturbed habitat to wander in, where they will remain until our return the following day.
The water samples we collect are taken back to our water quality lab where we can conduct more scientific tests. Keeping track of the water quality of the Detroit River is just as important as the data collected on the mudpuppies themselves. A database of this information will help us notice if severe changes have occurred in the water over time.
On Day 2, we return to the field to collect the traps as well as information on any mudpuppies captured overnight.
In the winter, the coast of Belle Isle can be quite treacherous. On one particular day in March, we faced some challenges as ice floes had moved into the shore overnight and were covering the traps we’d placed the day before. I was accompanied by two of the DZS’s most seasoned field researchers: Paul Buzzard, the director of conservation, and Marcy Sieggreen, curator of amphibians. Wearing insulated chest waders and long gauntlet-style gloves for protection against the icy waters, we did some ice stomping and managed to locate and recover all the traps we’d set.
Turned out we had captured one mudpuppy, so we proceeded to gather additional data – information from the animal, weather conditions and the water. We needed to take great care to keep the mudpuppy in the water at all times; in the winter this protects the skin and gills from freezing and in the warmer days of spring, summer and autumn it protects from the heat. We take measurements, weight and pictures of the animal, and if the salamander is healthy and large enough, a small transponder is implanted in the side of the tail to help with identification if recaptured. As quickly as possible, the mudpuppy is returned to the water in the area where we found it.
On Day 2, if conditions are favorable, we also use a digital boroscope to survey the site further. A boroscope, or a “plumber’s camera” as it’s sometimes called, is a camera at the end of a flexible 5-foot-long cable connected to a video screen. We use it to peek under rocks and logs in search of mudpuppies. This tool is a non-invasive way to learn about what else is living in the river.
As we continue with these surveys, we are exploring what other things the data we collect can show us from further analysis. We also plan to return to surveying areas off the coast off the island of Grosse Ile, which are also known to have a population of mudpuppies.
– Rebecca Johnson is the associate curator of amphibians for the Detroit Zoological Society.
Marcy Sieggreen was the curator of amphibians for the Detroit Zoological Society from 2008 until her passing in 2016. The Detroit Zoological Society established the Sieggreen Amphibian Conservation Fund in Marcy’s memory to continue to advance the work she so passionately championed.