Aquatic Ecology & Palaeoecology Research Program

About

Introduction

This page highlights and summarizes the research conducted by Dr. Anthony Swinehart and his students. Dr. Swinehart’s laboratory is located on the third floor of Hillsdale College's Dow Science Building. Research in his lab has included a variety of topics in aquatic ecology. However, the major focus is on wetland palaeoecology and ecological succession of aquatic ecosystems. Research is regularly conducted at Hillsdale's G. H. Gordon Biological Station in Luther, Michigan. Dr. Swinehart’s students work very hard on their research, and many have received awards at scientific meetings for their research presentations. Many of his students are currently involved in preparing manuscripts for publication. Graduates receive master's and doctorates in biology at top universities or gain employment immediately after graduation. If you are a high school student interested in aquatic ecology or palaeoecology, please take a moment to peruse this Web page and associated links. If you have any questions, or would like to schedule a visit to Hillsdale and meet with Dr. Swinehart, please e-mail him.
Applications of perch operculum morphometry to palaeolimnological reconstruction. Peter Cauley boils fish heads to extract the gill plate.Dr. Swinehart and his students are examining fossil opercula of yellow perch to compare growth patterns of fish that lived 6000 years ago (early Holocene of central Michigan) with those of modern day populations. This research is currently being submitted for publication. A more detailed summary will follow once the manuscript has been accepted. 

Discovery of 30,000-year-old spruce wood from central Indiana

A transverse section of spruce wood from Vermillion County, Indiana, dated at 30,000 years old.Dr. Swinehart and his students are examining organic remains recovered from a depth of 129 feet during drilling of a well in Vermillion County, Indiana. The remains included fragments of wood that were radiocarbon dated (using accelerated mass spectrometry) at 30,000 years old. There are very few dated records of organic material for this time period in Indiana. Examination of thin sections of the wood in various planes indicates that most of the fragments were spruce. One fragment had qualities similar to tamarack, but the observed characteristics are not conclusive. This data contributes to our understanding of Wisconsin-age climates and glacial chronologies. The research is in the process of being submitted for publication. More details will follow once the manuscript has been published.
An ecological characterization of the inland mangrove swamps of Grassy Key, Florida.
Amy Stone collects killifish and invertebrates in a landlocked mangrove swamp on Grassy Key, Florida.Dr. Swinehart and his students are examining the food web of land-locked mangrove swamps on Grassy Key, Florida. These wetlands are often highly saline, low in dissolved oxygen, and hot due to evaporation and lack of tidal and wave activity. As a result, these communities are like "aquatic barrens." However, many species of killish (Cyprinodontidae) thrive there. Those involved in the research are determining the diet of the killifish as well as surveying the biota of these wetlands so they can develop a food-web to characterize the ecological interactions there.

Palaeoecology of the Pipe Creek Sinkhole (Tertiary: Hemphilian) in central Indiana

The 5-million-year-old Pipe Creek Sinkhole in Grant County, Indiana.In 1997, when the Pipe Creek Sinkhole was discovered by workers at Irving Materials, Inc., in Grant County, Indiana, it was the first Tertiary-age deposit (5 million years old) ever discovered in the eastern interior of the continental United States. The sinkhole contained remains of extinct rhinoceros, camel, bear, wolf, giant tortoise, rodents, as well as turtles, snakes, and a variety of plant remains. We have been working on this deposit with scientists from Indiana-Purdue University at Fort Wayne since the discovery of the sinkhole. Dr. Swinehart’s lab is in charge of the botanical remains. So far, they have identified a number of wetland species (Chara, Polygonum) as well as trees (Sycamore, Beech, Poplar). A summary of the initial discovery was published in the American Midland Naturalist in 2001. Those conducting the research are currently working on more detailed analyses involving the sedimentary environment, as well as additional taxonomic work involving Scanning Electron Microscopy.

The role of dead and downed wood as summertime refugia for amphibians in a west-central Michigan forest

The red-back salamander (Plethodon cinereus), the most common summertime inhabitant of downed wood in the forests of the G. H. Gordon Biological Station of Hillsdale College. Forest canopy structure and litter (especially dead and downed wood) can be very important elements in determining biodiversity of a forest ecosystem. Forest management practices that result in the removal of dead wood might negatively affect the ecosystem. Dr. Swinehart and his students are examining one aspect of the role dead and downed wood has on biodiversity: its role as amphibian habitat during the summer months. They are collecting data on the stage of decay, length, diameter, and summertime amphibian inhabitants of dead and downed wood and using statistical analyses to indicate which characteristics of the downed wood are most favorable to amphibians.

Spatial and temporal variation in subfossil assemblages from peat cores taken in close proximity.

Amber Enright and Julia Parsons use a Russian Peat Corer to collect peat samples from a depth of over 40 feet at Guenther Bog, G. H. Gordon Biological Station of Hillsdale College.The fate of Chamaedaphne calyculata in the surface sediments of a west-central Michigan Sphagnum bog.
Dr. Swinehart and his students are studying Guenther Bog at Hillsdale's G. H. Gordon Biological Station in Luther, Michigan. On one project they are identifying and quantifying subfossils from 10-cm intervals from three separate cores and using multivariate statistical analyses to determine how appropriate it is to base palaeoenvironmental reconstructions on a single core. On a second related project, they are intensively sampling leatherleaf subfossils (an important ecological indicator species) from the surface peat of the bog and using degree of fragmentation and SEM analysis to see how persistant leatherleaf is in fibrous Sphagnum peat.

Reconstructing Palaeoenvironments in the context of extinct ice-age megafauna

The partially buried skull of the young Anderson The partially buried skull of the young Anderson Mastodont, Marshall County, Indiana.Mastodont, Marshall County, Indiana.Dr. Swinehart and his students work very closely with the research staff at the Indiana State Museum. Dr. Swinehart’s lab is responsible for analyzing microfossils and plant macrofossils for reconstruction of the palaeoenvironment in which things like mastodonts and mammoths lived (and died). Dr. Swinehart and his students are currently actively engaged in studying 7 mastodont localities; 6 in Indiana and 1 in Michigan. Most of these studies focus on macrofossil and sediment analysis, but one mastodont had preserved intestinal contents. Dr. Swinehart and his students are currently in the process of submitting a manuscript for publication that characterizes the diet of that animal. Another site, the Buesching Locality, has both mastodont and a fossil beaver dam. In addition to the standard sediment analysis, they plan to study the beaver works as a source for dendrochronology data and possible palaeoclimatic information.

The history of Celery Bog: Palaeoecology driven by community interest

Workers from Fox Drilling, Inc., use an Osterburg Piston Corer to collect peat samples from over 30 feet deep in Celery Bog, West Lafayette, Indiana.Celery Bog in West Lafayette, Indiana, has been the source of much controversy. Most of the controversy arose when a proposal to build a Wal-Mart next to the wetland was submitted. Environmental advocates were concerned about parking lot chemicals (oil, salt, etc.), washing into and harming the wetland. Old-timers then indicated that the wetland was not natural, recalling that they had farmed it in the 30's, and it only recently became wet. Scientists argued that the wetland was present prior to farming, was then drained for farming, and then when farming stopped in the '40's, the drainage tiles clogged and the area reverted to wetland. The City of West Lafayette, then provided a grant to Dr. Swinehart and Dr. Jonathan Harbor of Purdue University to solve the controversy using palaeoecological methods. Results show that the area was a lake 13,000 years ago and had slowly filled and became a wetland prior to human settlement. It was not only a wetland, but a very rare type of wetland; a Sphagnum bog. Wal-Mart was approved, but they donated money for the building of a public educational center. Analysis of the core and reconstruction of the paleoenvironment is still underway and will be submitted for publication.