Wisconsin springs

Wisconsin springs

Thermal imaging to characterize the spatial distribution of temperature in freshwater springs

Overview: During the Wisconsin Springs Gateway project, we will explore how local variations in topography, surficial geology, and bedrock geology influence the spatial distribution of temperature in freshwater springs. Cold and stable temperatures are often cited as important environmental conditions in springs, affecting species richness and diversity (Gaffield et al., 2005; Knight and Notestein, 2008; von Fumetti et al., 2017). However, there is currently a lack of information on the spatial distribution of temperature in springs and how distributions vary among springs of differing types. Using an infrared camera that is suspended above a spring pool, there are opportunities to examine the thermal properties of springs in a relatively quick and noninvasive manner. Our primary goal is to collect detailed temperature data sets from springs in a variety of geologic settings across Wisconsin. In the process, students will use thermal imaging infrared cameras and Trimble Juno® handheld data collectors, as well as learn a variety of flow gaging techniques and water sampling methods.

A spring emerging from fractured limestone in southwestern Wisconsin

When: July 1 – August 2, 2019

Where: Beloit, Wisconsin (introduction and lab work) and field sites across Wisconsin (field work).

Who: Three rising sophomores, one rising senior, and project leader Dr. Sue Swanson (Beloit College, [email protected]du)

Prerequisites and Recommended Courses: There are no specific coursework prerequisites for the three rising sophomores, but the project is ideally suited for students with interests in hydrogeology, fluvial geomorphology, water chemistry, and aquatic ecology.

The rising senior should have completed two or more of the following courses: hydrogeology, geomorphology, sedimentology, geochemistry, geographic information systems. The student will also serve as a peer mentor, so they should have prior experience as a teaching assistant or tutor.

All students applying for this project should enjoy being outside and walking through streams and wetlands in boots or waders (will be provided). We will also work in forested environments. All of these environments tend to have biting insects, such as mosquitos or ticks. Individuals should be open to using insect repellent and should be capable of carrying field equipment over uneven ground.

Expectations and Obligations:
All students
• Participation in all project-related work during the summer (July 1 – August 2, 2019).
• Commitment to work collaboratively in an environment of mutual respect.
Rising sophomores
• Write a team abstract and present a poster at the American Water Resources Association – Wisconsin Section annual meeting in spring 2020 (all expenses covered).
Rising senior
• Follow up data analysis at home institution and regular conference call with project director throughout academic year.
• Write an abstract and present a poster at the American Water Resources Association – Wisconsin Section annual meeting in spring 2020 (all expenses covered).
• Write a short contribution (4-6 pages text + figures) to be published in the Proceedings of the Keck Geology Consortium 2020 Volume (first draft due Mid-February).
• Expected but not required: Use this work for the completion of a senior thesis (or equivalent) at your home institution.

PROJECT DESCRIPTION

Thermal imaging holds potential for characterizing the spatial distribution of temperature in freshwater springs. Cold and stable temperatures are often cited as important environmental conditions in springs, affecting species richness and diversity (Gaffield et al., 2005; Knight and Notestein, 2008, von Fumetti et al., 2017). However, there is currently a lack of information on the spatial distribution of temperatures in springs and how distributions vary among springs of differing types, such as seepage/filtration springs or fracture springs (Figures 1 and 2). Using an infrared camera that is suspended above a spring pool, there are opportunities to examine the temperature distribution of springs in a relatively quick and noninvasive manner. Ground-based thermal imaging has been shown to differentiate between diffuse and focused groundwater discharge (Cardenas et al., 2008; Deitchman and Loheide, 2009) and initial testing of the use of a hand-held thermal camera to characterize springs of differing types in Wisconsin shows a distinction between seepage/filtration springs and fracture springs. Seepage/filtration springs display a right-skewed or bimodal distribution and higher standard deviation in temperature, whereas fracture springs display a bell-curve distribution and lower standard deviation (Kopas and Swanson, 2016).

Figure 1: Example of a seepage/filtration rheocrene spring.

Figure 2: Example of a fracture rheocrene spring.

The recently completed inventory of springs in Wisconsin mapped and characterized 415 large springs, or springs discharging approximately 0.25 cfs or more at the time of surveying (Figure 3) (Swanson et al., in review). Using this database, our primary goal will be to collect detailed temperature data sets from spring sites across Wisconsin. We will measure the temperature distribution within spring pools at a minimum of 20 rheocrenes (springs discharging to streams) selected from the Wisconsin springs inventory, ten with seepage/filtration morphologies and ten with fracture morphologies. Imagery will be collected in mid-July, when differences in spring pool and groundwater temperatures are at a maximum.

To complement the thermal data and further characterize spring pool characteristics that can influence aquatic habitat, field water quality indicators such as pH, specific conductance, and dissolved oxygen (DO), will also be measured and mapped across each spring pool. Following the characterization of the spatial distribution of temperature and each water quality indicator for each spring type, we will compare summary statistics, such as variance or skewness, to the spring flux (ft/s), defined as spring flow (ft3/s) divided by spring orifice area (ft2), for each spring. Spring flux provides a meaningful way to distinguish between groundwater discharge features dominated by discrete versus diffuse groundwater flow. The median fluxes for fracture or contact springs, seepage-filtration springs, and ponds in Wisconsin are 4x10-2 ft/s, 6x10-3 ft/s, and 1x10-5 ft/s, respectively (Swanson et al., in review). Robust relationships between temperature or other water quality summary statistics and spring flux, which is more easily measured, would then allow the use of spring flux as a predictor of the spatial distribution of temperature and water quality in springs of differing types.

Figure 3: Distribution and types of springs in Wisconsin (Swanson et al., in review).

Potential Student Projects: Students will work as a team throughout the project to organize and calibrate field equipment, image the distribution of spring pool temperatures, and measure and map water quality within the spring pools. After returning to campus, the three rising sophomores will work collaboratively on the thermal data set, while the rising senior (and peer mentor) will primarily work on the geochemical data set.

1. Thermal characterization of spring pools of differing spring types. The three rising sophomores will work together on the statistical analysis of the temperature data. This will involve downloading and organizing the thermal data from all of the field sites (>20), tabulating the thermal data and calculating summary statistics, and performing basic statistical tests, such an F-test of equality of variances. If there is time, we may also use spatial statistics (Moran’s I) to describe the degree to which temperature values similar in magnitude are clustered within spring pools of differing spring types.

2. Geochemical characterization of spring pools of differing spring types. The rising senior (and peer mentor) will take the lead on the statistical and spatial analysis of the water chemistry data. Similar to the temperature data, this will involve downloading and organizing the pH, conductivity, and DO data for all of the field sites (>20), tabulating data, calculating summary statistics, and performing basic statistical tests. However, because water quality data will be collected as point data, they must be processed before performing spatial statistics. During the following academic year, the rising senior will create isopleth maps of the spring pool parameters (using ArcGIS) and perform the subsequent spatial statistics as part of their senior thesis research.

PROJECT LOGISTICS

Students will arrive in Beloit, Wisconsin on July 1. The first week will be spent in the classrooms and laboratories at Beloit College, where students will be introduced to the project through a series of lectures, discussions, and local field excursions to springs within 1-2 hours driving distance. We will also discuss field safety and strategies for effective communication in the field, practice field methods, and gather equipment for field work. During this time, students will be housed on campus in Beloit College dorm rooms that are dedicated to the students for the entire 5-week program. The next two-and-a-half weeks will be spent mostly in the field, although we will return to Beloit on weekends. While in the field, the group will camp. All camping gear (tents, cooking gear) will be provided. Gear such as sleeping bags, sleeping pads, knee boots, and waders will be available for loan. The final week-and-a-half will include data analysis and preparation of our abstract and poster. Students depart Beloit on August 2.

PROFESSIONAL DEVELOPMENT

Conducting a research project at an early career stage is not only a résumé-builder, but helps to develop many skills that are applicable after the summer is over. Working and living together in the field, collaboratively completing a project from start to finish, and starting to develop a network of friends and colleagues all build resiliency, capabilities, and cognitive abilities. This Gateway Keck project offers these experiences in a supportive yet challenging environment. Students will work on real scientific questions, using standard and state-of-the art field and lab equipment; they will also receive training in science communication, including informal interactions with the public in the field, and more formal methods of presenting information such as lightning talks and giving better, more engaging research presentations.

References

Cardenas, M.B., Harvey, J.W., Packman, A.I., and Scott, D.T. (2008) Ground-based thermography of fluvial systems at low and high discharge reveals potential complex thermal heterogeneity driven by flow variation and bioroughness: Hydrological Processes, Vol. 22, doi: 10.1002/hyp.6932.

Deitchman, R.S., and Loheide II, S.P. (2009) Ground-based thermal imaging of groundwater flow processes at the seepage face, Geophysical Research Letters, Vol. 36, doi: 10.1029/2009GL038103.

Gaffield, S.J., Potter, K.W., and Wang, L. (2005) Predicting the summer temperature of small streams in southwestern Wisconsin: Journal of the American Water Resources Union, Vol. 41, doi: 10.1111/j.1752-1688.2005.tb03714.x.

Knight, R.L., Notestein, S.K. (2008) Springs as Ecosystems, in Summary and Synthesis of the Available Literature on the Effects of Nutrients on Spring Organisms and Systems: University of Florida Water Institute, p.1-46.

Kopas, D.C. and Swanson, S.K. (2016) The Application of Handheld Infrared Thermography in the Characterization of Springs in Southern Wisconsin, Geological Society of America Abstracts with Programs, Vol. 48, No. 7, Abstract 78-1.

Loheide, S.P., II and Gorelick, S.M. (2006) Quantifying stream-aquifer interactions through analysis of remotely sensed thermographic profiles and in-situ temperature histories: Environmental Science and Technology, Vol. 40, No. 10, p. 3336–3341.

Swanson, S.K., Graham, G.G., Hart, D.J. (in review) An inventory of springs in Wisconsin, WGNHS Bulletin.

Von Fumetti, S., Bieri-Wigger, F., and Nagel, P., 2017, Temperature variability and its influence on macroinvertebrate assemblages of alpine springs: Ecohydrology, Vol. 10, Issue 7, doi: 10.1002/eco.1878.

Montana dinosaurs

Montana dinosaurs

Exploring Late Cretaceous Wetland Ecosystems: Dinosaurs and Vertebrate Microfossils in Montana

Overview: Eight students will focus on collecting and interpreting the fossils of backboned animals found in the classic Cretaceous geological record of Montana with an aim of exploring diversity before the mass extinction event that wiped out the dinosaurs. The work will focus on fossils from the Judith River and Hell Creek formations. These formations preserve abundant vertebrate microfossil bonebeds (VMBs), which are concentrated deposits of mostly small bones and teeth from diverse organisms that inhabited ancient swamps and lakes (from tiny fish to giant dinosaurs, and everything in between). Students will work with collections housed at Macalester College and will conduct field and museum-based research in Montana, where they will discover, describe, and sample VMBs. Our work will yield novel insights into coastal plain ecosystems during the final stages of the Late Cretaceous, and will provide new data on a time of significant global change culminating in mass extinction (the K-Pg event).

Students in the field, Upper Missouri River Breaks National Monument

When: June 10 – July 12, 2019 (tentative)

Where: St. Paul/Minneapolis, Minnesota (introduction & lab work), Fort Peck Reservoir (Hell Creek Formation, Montana, field work); Upper Missouri River Breaks National Monument (Judith River Formation, field work), and Museum of the Rockies, Bozeman, Montana (museum research).

Who: Eight students and project leaders Dr. Raymond Rogers (Macalester College, [email protected]), and Dr. Kristi Curry Rogers (Macalester College, [email protected])

Prerequisites and Recommended Courses: Because this experience is for students early in their academic careers there are no specific coursework prerequisites. We are seeking students who are interested in many or all of the following: using field and laboratory methods to explore scientific questions about the ancient Earth, discovering and identifying fossils, understanding how fossils get preserved (taphonomy), using analytical tools to ask questions about organismal paleobiology (bone histology). Students should be comfortable sharing close quarters in tents (including in cold and rainy weather), camping at “primitive campsites” without running water or toilets, canoeing and swimming, hiking several miles in a day, and being without cell phone coverage for up to a week. Students will need to maintain composure in field conditions that are safe but that may include bad weather, difficult trail and boat conditions, and wildlife. Support in the form of field gear loans will be provided to students who do not own their own. All tents and cooking gear will be provided.

Expectations and Obligations:
1. Participation in all project-related work during the summer (approximately June 10-July 12, 2019)
2. Write abstract with team members and present a paper (poster or talk) at the Geological Society of America National Meeting in Phoenix, Arizona September 22-25, 2019 (all expenses covered).

PROJECT DESCRIPTION

This project builds on longstanding research in the Upper Cretaceous, dinosaur-bearing rock record of Montana focused on Vertebrate Microfossil Bonebeds (VMBs) – accumulations of the resilient hard parts (bones and teeth) of ancient organisms (Figure 1). The teeth, scales, and bones preserved in VMBs provide details on the ecology of ancient ecosystems. Our work will include an investigation of fossil collections housed at Macalester College, the Science Museum of Minnesota, and the Museum of the Rockies, and an exploration of the remote Montana landscapes of the Fort Peck Reservoir and Upper Missouri River Breaks National Monument (UMRBNM) in search of new fossil localities (Figure 2).

Figure 1: Carnivorous theropod dinosaur tooth within a vertebrate microfossil bonebed.

VMBs are fairly common in Mesozoic and Cenozoic terrestrial records, where they have been studied to recover the fossils of rare small-bodied organisms. They also serve as an important archive of relative abundance and species richness in ancient vertebrate communities (e.g., Brinkman et al. 2004, 2007; Demar & Breithaupt 2006; Sankey & Baszio 2008). Our Keck project will investigate the taphonomy and paleoecology of a select set of VMBs from classic localities within the Campanian Judith River and Maastrichtian Hell Creek Formation of north-central Montana (e.g., Rogers 1995, 1998; Rogers and Kidwell, 2000; Wilson 2008; Rogers and Brady 2010; Rogers et al. 2016, 2017, 2018). Students participating in this project will compare these classic VMB records from sedimentological, taphonomic, and paleoecological perspectives and work together to determine whether they represent similar formative histories or traveled unique pathways to the fossil record. Students will study VMB collections already housed at Macalester College, the Science Museum of Minnesota, and at the Museum of the Rockies, and they will travel to Montana where they will discover, describe, and sample VMBs in the field. Their efforts to compare and contrast VMBs in these distinctive formations will (1) advance our understanding of how VMBs form, (2) yield novel insights into the composition and structure of coastal plain paleocommunities during the final stages of the Late Cretaceous, and (3) provide new data on a time of significant global change culminating in mass extinction (the K-Pg event).

In addition, students will gain experience in:
1. Describing and interpreting common sedimentary rocks.
2. Identifying vertebrate and invertebrate fossils.
3. Sampling protocols for collecting rocks and fossils in the field.
4. Employing analytical laboratory methods (e.g., scanning electron microscopy, microscopic X-ray Fluorescence, bone histology) to answer questions.
5. Conducting the essential aspects of field work (e.g., maintaining a field notebook, utilizing topographic maps, prospecting, measuring stratigraphic section).
6. Learning to be an effective team member in the field and lab.
7. Producing and disseminating scientific information, especially to professional colleagues through presentation at the Geological Society of America meeting (September 2019).

Figure 2: Exploring Cretaceous exposures in search of fossil localities in the Upper Missouri River Breaks National Monument.

Potential Student Projects: We envision projects centered around VMB taphonomy, fossil identification, and paleohistology. At the outset, students will work as a team to sieve, recover, and identify vertebrate and invertebrate fossils from bulk matrix of the Judith and Hell Creek formations in storage at Macalester College. After some time spent on focused fossil recovery and identification, students will work in pairs to describe and interpret their fossil collections. Specific projects may include:

• Taxonomic characterization of fossil collections. Students with interests in paleoecology and evolution will explore the biodiversity of ancient lakes from the Campanian Judith River Formation and the Maastrichtian Hell Creek Formation. They will tabulate and compare faunal lists (presence/absence and relative abundance) and ultimately reconstruct and compare faunal diversity in Late Cretaceous freshwater ecosystems.

• Histological characterization of fossil collections. Students with interests in paleobiology and paleoecology will study bone histology of known ectotherms (crocodiles, turtles) and endotherms (dinosaurs, birds, mammals). Patterns of bone histology will be described and interpreted in the context of both taxonomy, animal physiology, and potential resource limitations in ancient Cretaceous ecosystems.

• Taphonomic characterization of fossil collections I. Students with interests in fossil preservation and taphonomy will compare bone modification features across formations, including breakage patterns, evidence rounding and abrasion, and tooth marks (and potentially other evidence of feeding/digestion).

• Taphonomic characterization of fossil collections II. Students with interests in fossil preservation and taphonomy will document in detail the size and shape of fossil bones and teeth collected from the Judith River, Two Medicine, and Hell Creek Formations. An automated image analysis approach will be used to capture size data and statistical approaches will be used to test whether the size and/or shape of fossils varies among sites and between formations.

Figure 3: Canoeing in the Upper Missouri River Breaks National Monument.

PROJECT LOGISTICS

Our tentative dates are June 10-July 12, 2019

Weeks 1-2. We’ll meet at Macalester College and students will be housed in dorms on campus until we depart for the field. While at Macalester, the group will dine in the Macalester dining hall, but there will be some opportunities to shop and cook dinners together, independent of the project leaders but with the help of their peer mentor. These weeks will be spent in the classrooms and laboratories at Macalester, where students will be introduced to the project through a series of focused lectures, discussions, hands-on experiences (e.g., fossil ID, methods of taphonomic characterization, bone histology). Students will process fossiliferous matrix and recover and identify fossils, The team will collect data and craft abstracts for the 2019 GSA meeting (to be submitted no later than June 25, 2019).

Weeks 3-4. We’ll depart Macalester and travel to Montana where we’ll visit a number of Cretaceous paleontological localities. During this interval we’ll be camping in remote field areas, canoeing and hiking in the search for new localities, cooking at our campsite, and making new fossil collections along the way. Our extended field excursion will include a stay in the Hell Creek Formation near Jordan, Montana, where we’ll connect with a field team from the University of Washington at their camp on the Fort Peck Reservoir. Here students will explore the K-Pg boundary and work to collect matrix and fossils from important Hell Creek fossil localities. From there, we’ll continue on to the Upper Missouri River Breaks National Monument (UMRBNM), where the Judith River Formation is well exposed. Here we’ll meet colleagues from the Bureau of Land Management in Lewistown, Montana, before heading into the Monument to conduct field research using a flotilla of canoes to access remote sites along the Missouri River (Figures 3, 4). When our work in the Judith River Formation is done, we will end our time in Montana with a trip to the Two Medicine Formation (the upland equivalent of the Judith River Formation) at the classic “Egg Mountain” field site, where the first North American baby dinosaurs were recovered in the 1970s. Finally, our trip will conclude with a stopover at the Museum of the Rockies in Bozeman, where our students will examine VMB collections and meet with museum curators, fossil preparators, and educators.

Week 5. We’ll return to Macalester for our last week so that we can integrate materials collected in the field into the collection, and we will assemble the text and imagery for our GSA poster presentations. While at Macalester, the group will dine in the Macalester dining hall (and perhaps shop and cook some dinners together, independent of the project leaders but with the help of their peer mentor).

Safety
The project directors are experienced field scientists with decades of experience working at these remote field localities. They are familiar with safety issues specifically related to wildlife, rapidly changing weather conditions, and canoeing/hiking. There is little question that there are a host of inherent risks in this proposed work, but we will try to minimize this risk through training, communication, assessment of student abilities, and planning. We’ll have a satellite phone and wilderness first aid kits at all localities in case of emergency. Here we briefly address the most common concerns.

Wildlife: We will spend the bulk of our field time camping in remote regions with wildlife including rattlesnakes, black bears, and mountain lions. Students will be trained by the project directors in camping/hiking safety.

Canoes: To collect samples in remote, roadless areas, we will be canoeing to some field sites. Students are required to wear personal flotation devices at all times, and the river shoreline is always visible. Students will always canoe with at least one other person, with clear communication about the planned route and expected time on the water.

Weather conditions: The weather in the Montana can be quite unpredictable and variable, with some days/nights up to 100° F and others at/near freezing temperatures. Heavy rain and wind, hail, and snow are all possible, as are very hot sunny days. Warm clothing and layers are all necessary, including rain gear. A day pack (medium sized backpack) is important for all students so they can carry sufficient clothing, and food every day, including 2-3 large water bottles. Sunscreen, hats and gloves, sunglasses, and sturdy hiking shoes/boots are key for student safety and comfort.

PROFESSIONAL DEVELOPMENT

This Gateway Keck project will allow students to develop skills that will last long after the summer is over in a challenging, but supportive environment. Working and living together in the field, collaborating to complete a project from start to finish, and beginning to develop a network of friends and colleagues all build resiliency, competencies, and expertise. Students will work on real scientific questions, using standard and state-of-the art field and lab equipment; they will also receive training in professional science communication. In addition, students will have chances to interact with people across the workforce working as professional geoscientists, from graduate students, professors (the PIs, as well colleagues from the University of Washington and Montana State University), museum professionals (at the Science Museum of Minnesota and the Museum of the Rockies), to those in government positions (Bureau of Land Management employees). These interactions will help set the stage for a broadened view of where a degree in the geosciences can take you, and open the door for future possibilities.

Selected References

Brinkman, D.B., D.A. Eberth, & P. J. Currie. 2007. From bonebeds to paleobiology: applications of bonebed data. In: R. R. Rogers, D. A. Eberth, and A. R. Fiorillo (eds.), Bonebeds: Genesis, Analysis, and Paleobiological Significance. University of Chicago Press, Chicago.

Brinkman, D.B., A.P. Russell, D.A. Eberth, & J. Peng. 2004. Vertebrate palaeocommunities of the lower Judith River Group (Campanian) of southeastern Alberta, Canada, as interpreted from microfossil assemblages. Palaeogeography, Palaeoclimatology, Palaeoecology 213:295-313.

Demar, D.G., Jr., & B.H. Breithaupt. 2006. The nonmammalian vertebrate microfossil assemblages of the Mesaverde Formation (Upper Cretaceous, Campanian) of the Wind River and Bighorn Basins, Wyoming. In: S. G. Lucas & R. M. Sullivan (eds.), Late Cretaceous Vertebrates from the Western Interior. Bulletin of the New Mexico Museum of Natural History and Science 35:33-53.

Rogers, R.R. 1995. Sequence stratigraphy and vertebrate taphonomy of the Upper Cretaceous Two Medicine and Judith River Formations, Montana. Unpublished Ph.D. Thesis, University of Chicago, Chicago.

Rogers, R.R. 1998. Sequence analysis of the Upper Cretaceous Two Medicine and Judith River formations, Montana: nonmarine response to the Claggett and Bearpaw marine cycles. Journal of Sedimentary Research 68:615-631.

Rogers, R.R. & M.E. Brady. 2010. Origins of microfossil bonebeds: insights from the Upper Cretaceous Judith River Formation of north-central Montana. Paleobiology 36:80-112.

Rogers, R.R. & S.M. Kidwell. 2000. Associations of vertebrate skeletal concentrations and discontinuity surfaces in terrestrial and shallow marine records: a test in the Cretaceous of Montana. Journal of Geology 108:131-154.

Rogers, R.R., K.A. Curry Rogers, B.C. Bagley, J.J. Goodin, J.H. Hartman, J.T. Thole, & M. Zatoń. 2018. Pushing the record of trematode parasitism of bivalves upstream and back to the Cretaceous. GEOLOGY 46: 431-434.

Rogers, R.R., K.A. Curry Rogers, M.T. Carrano, M. Perez, & A. Regan. 2017. Isotaphonomy in concept and practice: an exploration of vertebrate microfossil bonebeds in the Upper Cretaceous (Campanian) Judith River Formation, north- central Montana. Paleobiology 43:248-273.

Rogers, R.R., S.M. Kidwell, A. Deino, J.P. Mitchell, & K. Nelson. 2016. Age, Correlation, and Lithostratigraphic Revision of the Upper Cretaceous (Campanian) Judith River Formation in its Type Area (north-central Montana), with a Comparison of Low- and High-Accommodation Alluvial Records. Journal of Geology 124:99-135.

Sankey, J.T. & S. Baszio (editors). 2008. Vertebrate Microfossil Assemblages: Their Role in Paleoecology and Paleobiogeography. Indiana University Press, Bloomington.

Belize corals

Belize corals

Resilience and decline: Are we at a tipping point for endangered Acropora sp. corals in Belize?

Overview: Acropora cervicornis (Staghorn coral) and Acropora palmata (Elkhorn Coral) have been important coral reef builders throughout the recent geologic past. Yet thriving acroporid populations are now exceptionally rare in the Caribbean. Causes cited for the dramatic decline of this (and other coral) species vary, but are virtually all tied directly or indirectly to human-induced environmental or climatic change. In the most recent years we have seen an explosion of research documenting the rapid decline of corals worldwide, and dire predictions of looming collapse. But hope remains that there may be some coral refugia to withstand collapse long enough for local, regional, or global intervention and/or stabilization to occur. Coral Gardens, Belize is one candidate for persistence of endangered Acropora sp. corals, but for how long, we do not know. It is critical to understand working systems if we hope to promote persistence in coral communities, recruits for transplantation, best practices in management, and an understanding of human/environment interactions moving into a climate-stressed future. This project is aimed at assessing the current status of living acroporid-dominated coral reefs off Ambergris Caye, Belize, and expanding the range of previous work in this area.

Keck Geology students studying corals along a transect.

When: June 14-July 18, 2019 (tentative)

Where: Laboratory work at Washington and Lee University (Lexington, Virginia) and field studies in Ambergris Caye, Belize.

Who: Eight students, a peer mentor (Ginny Johnson, W&L ’20), and project directors Dr. Lisa Greer (Washington and Lee University, [email protected]) and Dr. Karl Wirth ([email protected])

Prerequisites and Recommended Courses: Because this experience is a Gateway Project, there are no specific coursework prerequisites. We are seeking students who are interested in many or all of the following: coral reefs, the fossil record, ecosystem dynamics, geochemistry, human impacts to the environment, natural and manmade climate change, and using field and laboratory methods to explore scientific questions about Earth systems.

All students are required to be capable swimmers. This does not mean that students need be expert swimmers, but that they can be safe in the water for prolonged periods (see below). Soon after acceptance to the project students will be required to submit a completed PADI scuba medical questionnaire (and signed by a doctor for certain pre-existing conditions). Prior to arriving at Washington and Lee for the start of the project participants will submit a signed (by swim coach or athletics staff at their home institution) form certifying that the student can complete the minimum swim skills required for SCUBA certification (swim 200 yards and float/tread water for 10 minutes). These skills will be tested again at the beginning of the confined water scuba training. Students should indicate their comfort in water in their application materials. Students should be willing to live in close quarters, be in the heat and sun for much of the day, be on a boat for much of the day, and work well with others.

Expectations and Obligations:
1. Participation in all project-related work during the summer (5 weeks)
2. Submission of an abstract (individual or in groups) and presentation of a paper (poster or talk) at the Geological Society of America National Meeting in Phoenix, AZ or the American Geophysical Union meeting in San Francisco in Fall 2019 (all expenses covered).

PROJECT DESCRIPTION

The goals of this project are to determine 1) whether acroporid reefs at Coral Gardens, Belize are in recovery or continued decline after Hurricane Earl and whether heat-induced stress dramatically impacted living coral in 2016, 2) the degree to which recent decline has theoretically impacted reef accretion rates at this site, 3) how well our previous remote satellite-based mapping of living coral serves as an accurate predictor of coral abundance, 4) the temporal persistence of corals at this site using radiocarbon and uranium series dating of critical time periods, 5) past environmental conditions using geochemical proxy data, and 6) whether temperature and light data show significant change over the period of study (2011-present) and whether there is environmental heterogeneity across several reef sites. In addition, we will expand the study beyond the area we have been working in since 2011. This project will use photographic, in situ, satellite, and laboratory measurements of coral and algal growth, herbivore density, environmental conditions, and coral chemistry to characterize reef ecosystem dynamics in time and space.

Figure 1: Map of Coral Gardens on the Mesoamerican Barrier Reef off the coast of Belize. Map A shows the relative location in the Caribbean and map B shows the location of Coral Gardens and marine reserves near the study site. Red squares at Coral Gardens (C) mark buoys and straight black lines mark coral transects within the study area. D is a detailed map of live coral produced by 2014-15 Keck students.

Background
Acroporid reefs in decline: Acroporid coral species are currently experiencing massive die-offs throughout the Atlantic basin and A. cervicornis and A. palmata are listed as threatened on the U.S. Department of the Interior Endangered and Threatened Wildlife list. Many scientists fear that A cervicornis may be particularly sensitive to environmental change and the demise of the species may be a sign of impending doom for Caribbean reefs in general (e.g. Precht and Aronson, 2004). A primary cause for collapse is White Band Disease (Rogers, 1985; Aronson and Precht, 2001), but many anthropogenic factors may be enhancing or driving disease effectiveness. Of the human-influenced threats to corals, macroalgae abundance due to overfishing and eutrophication, climate change, and potentially ocean acidification seem most important. In the last few decades reefs have experienced dramatic shifts from coral- to algae-dominated ecosystems (Hughes, 1994; Pandolfi et al., 2005), and it is now abundantly suggested that climate change may induce a massive collapse in coral reefs worldwide (e.g. Hughes et al., 2017; 2018).

Most living A. cervicornis today exist in small patches and isolated colonies, and true A. cervicornis-dominated ‘reefs’ are now rare (Miller et al., 2009). The question of whether the recent die-off of acroporids is anomalous with respect to the geologic record has been a subject of debate. Several key studies on the persistence of A. cervicornis prior to the 1980’s have been from Belize (Aronson et al., 1998; Aronson et al., 2002; Wapnick et al., 2004).

Project Location: Ambergris Caye is an extension of the southernmost Yucatan Peninsula and is situated northeast of mainland Belize. This project will primarily take place at a site called Coral Gardens, off the southern tip of Ambergris Caye, Belize which sits between the 1,116 hectare Hol Chan Marine Reserve, created in 1987, and Caye Caulker Marine Protected Areas (Fig. 1). Coral Gardens has no protected status. The modern Belize barrier reef system began to develop as a fossil reef platform at the peak of the last interglacial, and the youngest limestones exposed on Ambergris date ~125,000 ybp (Mazzullo et al., 1992). Flooding of the platform ~6,500 ybp created extensive lagoonal patch reefs forming inland of the barrier reef crest where Acropora sp. corals have been dominant reef builders off Belize for at least much of the Holocene (Aronson et al., 2002) until the 1980’s.

The center of Coral Gardens is composed of acroporid-dominated patches that are variably connected to one another. Since 2012 the Greer lab has been monitoring live coral cover at Coral Gardens along 5 established semi-permanent transects (Fig. 1). Each transect end has been marked with rebar stakes, underwater buoys, and high resolution GPS measurements (Fig.  2). Each year photographs are taken of individual quadrats placed along each transect. Images are rectified and scaled and live coral is manually segmented as overlays on each quadrat. Areal coverage is quantified using MATLAB and all living coral tips are mapped on each image (Fig. 3). Temperature, light, and conductivity have been measured at up to 15 minute intervals across Coral Gardens and additional reef locations since 2013. In some years (including during a 2014-2015 Advanced Keck project), many other variables have been assessed at Coral Gardens, including genetic diversity, herbivore abundance (fish and urchins), reef bathymetry, and sediment character.

Figure 2: Each reef transect location is marked by rebar stakes, buoys, and GPS coordinates at both ends.

Prior Data from Coral Gardens
Quantitative high-resolution data on percent live coral tissue have been collected from 2012-2018 from Coral Gardens. Coral Gardens was also the subject of a 2014-2015 Advanced Keck Project. Data from prior field studies at Coral Gardens suggested that A. cervicornis populations (as well as A. palmata and the hybrid species A. prolifera) were anomalously healthy and robust at Coral Gardens, Belize. All three acroporid species (A. cervicornis, A. palmata, and A. prolifera) were present, live acroporid tissue abundance was high in many places, actively growing branch tips were common, and new coral recruits could be seen colonizing recently dead coral rubble and framework. However, 2016 saw a significant change in live coral tissue, following high 2016 El Nino temperatures and Hurricane Earl (Normile, 2016). Live coral has declined at every transect site since 2012, but the rate and timing of decline has varied across these sites. There is some hope that corals have ‘stabilized’ at 2 of the 5 locations, and the 2019 data may prove critical to assessing whether this reef can ‘bounce back’ after the challenging conditions of 2016.

Our work to date at Coral Gardens has shown that this location contains some of the largest and most extensive Acropora sp. coral populations yet documented in the Caribbean (Greer et al., 2015; Busch et al., 2016). While we have high-resolution longitudinal data from the 5 established transects at Coral Gardens, reconnaissance data from the 2014-2015 Keck Advanced project revealed many additional areas of Acropora sp. coverage in the wider area around Coral Gardens. The study by Busch et al. (2016) attempted to map these areas using satellite imagery. Initial field verification shows remarkable accuracy of this remote sensing tool. At a time when we are seeing declining live coral cover at our original sites it may now be critical to locate and establish monitoring efforts at additional locations of abundant living coral.

Radiocarbon and high resolution uranium-series data show living Acropora cervicornis coral existed at this site from at least 1915 to 2015 (Waggoner et al., 2015; Greer et al., 2016; and Waggoner, 2016 unpublished thesis). While our last Keck Project focused on determining whether Coral Gardens was a true refugia (in the ecological sense and in geologic time), this study collaboratively aims to determine whether Coral Gardens might remain a refugia, assess the geological impacts of declining coral at this site, and to locate the most promising sites of refuge within a larger geographic area.

Potential Student Projects
We envision a wealth of possible student research projects at this location. Potential student projects include the following:

Project 1: Is live A. cervicornis increasing or decreasing at Coral Gardens and is this reef in a phase transition from coral to algae dominance like most other reefs in the Caribbean? All students will participate in this project to some degree, as they will all contribute in some way to the photographic data analysis. A few students could easily make this the focus of their research experience, and several complimentary, but individual projects could evolve. We will conduct a comparative quantitative analysis of live coral tissue, macroalgae, and bare rock abundance from 2014-2019 to determine whether the coral or algae are increasing or in decline within and between sites at Coral Gardens, but also to what degree coral abundance is heterogeneous across the transect sites (which is clearly the case). 2-3 students.

Project 2: How successful was the Busch et al. (2016) remote sensing method for mapping coral populations, and can we identify and establish new habitat mapping areas in the greater Coral Gardens region? As living coral declines at our original sites it may become imperative that we find additional refugia sites to monitor moving forward. Reconnaissance of potential new acroporid sites based on satellite imagery will also provide the opportunity to better assess the novel Busch et al. (2016) mapping technique. New transects will be established at these sites. 2-3 students.

Project 3: How persistent has acroporid growth been at Coral Gardens through the well-documented period of coral decline and in recent geologic time? We already have data that indicate persistence of coral growth at Coral Gardens. But we have many samples that have not yet been dated. One project could focus on trying to obtain dates from stratigraphic sections with poor age constraint (e.g. 1925-1945 or the 1970’s). Another could focus on preparing modern samples (already in hand) to contribute to a refinement of the radiocarbon calibration curve for the Caribbean (Druffel, 1981; Reimer et al., 2013). This project would involve sample assessment for geochemical analysis (using the SEM and XRD), sample preparation for dating and analysis of geochemical data. 1-2 students.

Project 4: What is the relationship between living coral and overall carbonate budget for Coral Gardens and how heterogeneous is it across time and space? We can determine roughly how much carbonate accretion is taking place at Coral Gardens reef by estimating live coral abundance, and using published data on coral growth rates and skeletal density of coral samples for each transect site and the whole Coral Gardens reef. We can roughly estimate how fast carbonate is being excavated from reef framework by quantifying net annual bioerosion by grazers (fish and urchins) (Griffin et al., 2003 Mumby et al., 2006; Brown-Saracino et al., 2007); and macroborers from the literature (Hubbard et al., 1990; Perry et al., 2013) and the 2014-2015 Keck Advanced project to compare 2019 data with data from past years. We will place our estimates in the context of previous estimates of reef accretion from the literature. A key question centers on the degree to which the decline in live coral that we are observing will impact the geologic system as a whole. This project can easily involve several students with collaborative focus on fish, urchin, and damselfish surveys, net carbonate calculation, and the living coral dataset. 3-4 students.

Project 5: Do environmental measurements show a marked increase in temperature, conductivity, and/or light at this site from 2012-2019, and to what degree are these changes synchronous off the coast of Ambergris Caye? We have been collecting temperature data at 15 minute intervals across Coral Gardens, on land, and at additional sites (Manatee Channel to the south, and Rocky Point to the north) since 2012. We also have variable conductivity and light data from several sites. These sites span the length of Ambergris Caye, variable shallow depths, and variable exposure to open-marine water. A key question we originally asked of this project (in 2011) was what is contributing to the survival of the Coral Gardens refugia? To date we have not done a systematic analysis of the environmental data to see whether temperature at this site may have contributed to success (via exposure to flushing of ‘new’ and possibly cooler water from outside the reef), and whether temperatures are now exceeding the recent norm at this site. 1 student.

Project 6: Do stable isotope measurements from corals living over the last 100 years show a changing environment? We have Acropora cervicornis samples dating from at least 1915-2015. Very few of these samples have been analyzed for stable isotopic composition. Following a framework used by Greer et al. (2009) to investigate temperature changes crossing the mid-Holocene Thermal Maximum, we could pair radiocarbon dates with stable isotope composition to see if there are any discernable trends in temperature at this site (assuming salinity has roughly remained the same) over the last 100 years. If we could detect change on that scale, it might be the first to do so using this species of coral. 1-2 students.

Figure 3: Image A shows placement of a quadrat along an established transect and B shows the original photograph. C shows a rectified and scaled image (using MATLAB) and D shows the manual tracing of live coral cover. E shows the same image used to quantify live coral using MATLAB and F shows a map of living coral branch tips.

PROJECT LOGISTICS

Students will complete an online SCUBA knowledge course prior to the start of the project period. This course develops the knowledge base needed for SCUBA certification.

Washington and Lee University: We will spend approximately 1 week in Lexington prior to departure for Belize. The focus of this week is to explore important concepts in reef science, and develop the knowledge and skills needed for field research. Students will learn about the methods we will use, explore prior data from Coral Gardens, and learn to identify the major corals and reef organisms. We will also complete the early portion of the SCUBA certification in the W&L swimming pool.

Belize: We will spend approximately 2 weeks in Belize collecting data from the field sites using both snorkel and SCUBA. In addition to conducting all aspects of the field work, students will also complete the open-water dives for SCUBA certification, and participate in field lectures by Dr. Ken Mattes (TREC Belize; Fig. 4) and snorkeling experiences in a variety of reef habitats. We hope to also take one day to visit Mayan ruins and talk about the impacts of climate change on the Mayans.

Washington and Lee University: We will spend the last two weeks of the project period at Washington and Lee. Here students will learn analytical and computational techniques and they will quantify/analyze data. They will use the X-Ray Diffractometer (Fig. 5), Scanning Electron Microscope, High-Resolution Micromill, and Stable Isotope Mass Spectrometer. Students will process photographic data using a number of software programs including MATLAB and analyze large environmental datasets using excel. In the last week we will work with students to craft posters and abstracts, for presentation at a Fall national Geosciences meeting (GSA in Phoenix or AGU in San Francisco).

Figure 4: Accommodations at the TREC Belize research station.

Figure 5: Keck Geology students using the x-ray diffractometer to study Belize samples.

Figure 6: Keck Geology student studying Belize samples using a scanning electron microscope (SEM).

PROFESSIONAL DEVELOPMENT

Conducting a research project at an early career stage is not only a résumé-builder, but helps to develop knowledge and skills that are important to many educational, career, and life goals. Working and living together in a supportive yet challenging environment, completing a collaborative project from start to finish, and starting to develop a network of friends and colleagues all build identity as a scientist, resiliency, capabilities, and cognitive abilities. Students will work on authentic scientific questions and be trained to use state-of-the art equipment and methods. Project participants will also learn to communicate the results of their scientific investigations in both informal (e.g., general public) and formal (e.g., other professionals in the discipline.

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