Wooster Geologists

The HYDRO25 Macroinvertebrate team.

Guest bloggers: Phillipp Drappatz and Elliot Miller, the Hydrology class at the College of Wooster performed a macroinvertebrate survey on 8/25/25 on Apple Creek in Wooster. The first lab of the semester was a trip to Grosjean Park in Wooster. The class was joined by and guided by macroinvertebrate expert Carry Elvie from the CFAES who is also the director of the Bug Zoo. Apple Creek unusually for Ohio is a freestone trout stream under the stewardship of the Clear Fork River chapter of Trout Unlimited, which has been performing surveys since 2012. The purpose of this fieldtrip was to add on the current Trout Unlimited record and to gain insight into the health of the stream based on the assemblage of macroinvertebrates.

Students using D-nets and kick nets to sample. Aaron in the foreground takes water temperatures and geochemical measurements. Note in the background the stream has been recently modified in an ogoing stream restoration project.

In the tray above we can see a variety of macroinvertebrates separated into groups. On the top row left to right are caddis fly larvae, another different species of caddis fly larvae and a water penny. On the bottom row left to right are yet again another species of caddis larvae, more caddis larvae, annelid worms/leeches, a mayfly larva, and a different species of mayfly larvae.

Pictured above is a bycatch of small fish including shiners, stoneroller minnows, and mosquito fish. Macroinvertebrates pictured include a crayfish, a snail and a water slider climbing up the side

Carrie gave the group a debrief and we headed back to the lab to summarize the data and write the report.

The upshot of the data is the pollution tolerance index at two sites in Apple Creek shows high water quality. This measure is based on the occurrence of the various species mentioned above. The ratings of the mid 20s is an excellent rating in terms of water quality and we have discussed the possible impact the stream restoration and early fall sampling. Note that there is a decline in the curves above at both sites and this will be closely watched as future surveys are done.

Coring a lake usually involves… a lake. In this case, Dr. Eva Lyon and colleagues from Ohio University are studying Paleolake Buckeye, which probably last had water in the late Pleistocene, over 15 thousand years ago. To study the paleolake, Lyon and colleagues have been collecting sediment cores from what was once the bottom of a lake in eastern West Virginia. In late summer 2024 and 2025, Lyon and Nick Wiesenberg traveled to WV, Livingston corer in tow, to retrieve these cores.

The 2024 campaign, pictured above, was much more successful. Although the stream channel we cored in was dry at the time, a small stream usually trickles through, thoroughly saturating the sediments below our feet. We pulled out over three meters of core, the bottom of which we determined to be over 28,000 years old!

This summer, we tried a different spot, near what we determined to be the middle of the lake, Unfortunately, decades of mowing and cattle grazing, coupled with much less infiltration and saturation made this a much more resistant substrate for coring. We came up empty.

The cores retrieved in 2024 were analyzed this summer by a number of COW undergrad student researchers. Pictured above is Damien Gately operating the magnetic susceptibility probe on the core. This instrument provides an estimate of the relative amounts of iron-bearing minerals in a sample. This measure is often related to grain size, so we can also use it to help us track changes in grain size throughout a core.

There will be much more work to come on this record of late Pleistocene climate and environmental change – stay tuned!

Guest Bloggers – SEAK25: On the third and final day in Angoon, we split into two groups. One climbed Hood Bay Mountain to extract high-elevation mountain hemlock cores, the other kayaked to Turn Point, searching for and coring culturally modified trees (CMTs). 

The CMTs at Turn Point are Sitka Spruce that have distinct scars with hack marks, evidence of previous Tlingit generations harvesting sap and fire starter. These CMTs are of heightened interest because a new hydroelectric power plant is soon to be built, and its road will require the removal of many trees in Turn Point. High school students in Angoon have already worked to preserve the CMTs by creating photogrammetric renderings. This work will prevent the information from there valuable trees, which connect locals to their lineage, from being lost altogether. We hoped to contribute to the effort by extracting cores to investigate their growth and date the scars using tree rings.

A map showing Turn Point in relation to Angoon. Turn Point will be the site of a hydroelectric plant for power generation for Angoon, which is now powered by a diesel generator. 

We embarked on this mission in the morning, leaving from the seaplane dock on kayaks. We had to cross the Stillwater Anchorage inlet and saw a pack of seals and an immature bald eagle on the way.

The crew getting ready for the crossing.

Dexter and Landon crossing the Inlet.

We arrived after thirty minutes of paddling and quickly got to work. Finding the CMTs was rather challenging. Cody and Angel, high schoolers who had worked on the CMTs previously, were a part of the team, and they showed us the location of the CMTs athough we still struggled to trudge through the muddy terrain. We began by extracting five cores from each tree: one in the scar, one above the scar, one on the opposite side from the scar, and one on each side ninety degrees around the tree from the scar. For each tree, we hoped to be able to crossdate the scar core with the other cores, allowing us to obtain its age (the age of the scarring of the trees). Once we started coring, though, we realized that mst of the scar surfaces were too rotted for direct sampling. However, we tried coring next to the scars, and we noticed that roughly at the depth of the scar, the core became extremely sappy – in many cases, so sappy that we could not continue boring. We attribute this to a key spruce defense mechanism – when harmed, the wound is flushed with sap. This worked perfectly to the Tlingit’s advantage, allowing them to easily collect sap, and to ours as well, hopefully allowing us to effectively date the scars without actually coring into them. Essentially, the sap is a proxy for the scar. We adjusted our strategy to take two cores from each CMT, one just to the left of the scar, and one just to the right. By the end of the day, we cored around 15 CMTs.

Cody, Landon, and Dexter extracting cores.

Dr. Wiles extracting a core.

After a long day of coring, we returned to the kayaks and began the journey back across the inlet. This paddle was difficult, as the tide was heartily fighting our strokes. Fortunately, many of us still managed to join the bull kelp club, a distinctive organization constituted of those who have eaten raw bull kelp. It was salty and very slimy.

The extracted cores must dry for a couple of weeks, but will be processed at the Wooster tree ring lab. Upon obtaining dates and results from further analysis, the information will be shared with the Alaska Youth Stewards, contributing to and expanding upon their work with the CMTs.

The work of Keck SEAK25 is funded by the Keck Geology Consortium and the National Science Foundation.

Guest bloggers SEAK2025: We began Day 2 at Angoon High School, learning about student research focused on the preservation of Culturally Modified Trees (CMTs). A CMT is any tree that has been modified by indigenous people for cultural or practical reasons. This often includes bark removal for sap harvesting or building material. The group’s project is rooted at the intersection between culture and mathematics, or ethnomathematics. The team of students worked to preserve a cluster of CMTs on Admiralty Island using Light Detection and Ranging (LiDAR) imaging, creating a digitized 3D model of each CMT. We would later have the opportunity to see CMTs at two different localities on Admiralty Island during our third day in Angoon.

Image: Frank Coenraad (of Chatham School District) orienting everyone with CMT research. Under the direction of Frank, the team of Angoon High students placed first at a regional conference in Juneau. They will compete at the Advancing Indigenous People in STEM (AISES) National Conference in Minneapolis, Minnesota, held in October 2025.

After an exciting start to our day, we delivered a presentation on the principles and practices of Dendrochronology to Alaska Youth Stewards (AYS) crew members and faculty. The presentation included field and lab methods, data interpretation, and how we each plan on using dendrochronology for further research.

Image: KECK students presenting to AYS crew members and faculty. Angoon High School, Angoon, Alaska.

 Image: AYS crew members getting hands-on experience learning how to properly mount tree cores.

Image: Nick Wiesenberg teaching students how to analyze tree cores under a microscope after they’ve been mounted and sanded.

After the morning presentations, we set out to explore low tide along the coast; the low tides during our stay were especially low. Referred to as negative low tides, these tides occur when the water level drops below the average low tide zone, exposing areas that are typically submerged. Below are some of the critters and settings observed during the course of the negative tide – the AYS group also explained the traditional uses of some of the seaweed.

We concluded our day collaborating with an ongoing project, led by S’eiltin Jamiann Hasselquist, that seeks to restore Tlingit burial sites to their former glory. We focused our efforts on a cemetery off of Killisnoo Rd. south of Angoon proper. A major effort was cleaning up the site and rolling back the moss and roots masses that have grown over the site. The team revealed grave sites that were covered.

The work of Keck SEAK25 is funded by the Keck Geology Consortium and the National Science Foundation.

Guest bloggers – SEAK25: The SEAK Team traveled to Juneau Alaska from Wooster where they had been learning the basic of tree-ring dating and dendroclimatic analyses,

After spending a couple days in Juneau, our Keck SEAK 2025 Team took a seaplane to Angoon.

Seaplane at the airport waiting for takeoff! Half the team traveled to Angoon on the amphibious float plane (above) and the other half traveled via the Beaver (below) on floats.

Alaska Seaplanes Beaver on floats.

A view of Angoon’s west beach, the old ferry dock, and the first cemetery site (located next to the church, white building on the hill).

Upon arrival, we met with the Angoon Alaska Youth Stewards (AYS) group. AYS “employs a new generation of environmental and cultural leaders to care for [their] lands, waters, and communities” (Alaska Youth Stewards, 2025).

Our first meeting with the AYS crew at the forest service cabin, talking logistics about the next couple of days.

An AYS crew member coring a tree for the first time!

Another AYS corer!

We took a brief lunch and reconvened in the afternoon with S’eiltin Jamiann Hasselquist. Jamiann told us her story: She was born and raised in downtown Juneau, but her mother was from Angoon. Jamiann is involved with Haa Tóoch Lichéesh (HTL), a nonprofit that has organized Orange Shirt Day events, ocean dips, and cemetery cleanup (Juneau Empire, 2024). To honor her mother and give back to the community of Angoon, Jamiann has undertaken the large task of cleaning up and restoring some of the local cemeteries. We and the AYS crew joined in Jamiann’s efforts.

During cleanup, we uncovered a massive slab under the shrubbery. Jamiann cleaned it off, looking for any engravings.

Jamiann posing with the a headstone that we uncovered and stood up.  Prior to cleanup, this headstone was buried underneath the road.

Also on Day 1, we visited a second site with a massive obelisk. Here, we focused on clearing the weeds and cutting down a tree so the obelisk was more visible from town. 

AYS, Jamiann, and SEAK 25 with the obelisk.

Panorama looking west toward the offshore to Chicagof Island.

References

Reid, M. (Ḵaa Yahaayí Shkalneegi). (2024). Resilient peoples and place: Catalyzing healing – a Q&A with S’eiltin Jamiann Hasselquist. Juneau Empire. https://www.juneauempire.com/news/resilient-peoples-and-place-catalyzing-healing-a-qeiltin-jamiann-hasselquist/

Sustainable Southeast Partnership. (2025). Alaska Youth Stewards. Sustainable Southeast Partnership. https://sustainablesoutheast.net/sub_focus_area/alaskan-youth-stewards/

The work of Keck SEAK25 is funded by the Keck Geology Consortium and the National Science Foundation.

Special thanks to Nat McCoy and Dr. Pollock for their hard work on the Earth Sciences 2024-2025 Annual Report. You can access the report through this link.