The Geology Department’s annual field excursion course traveled to Puerto Rico to study the effects of climate change on coastal erosion and coral reefs. Students visited coastlines, went snorkeling along coral reefs, discussed Hurricane Maria recovery efforts with a local journalist, visited El Yunque National Rainforest, and toured a variety of indigenous and historical archeological sites. In preparation for the trip, students learned about the geology, indigenous and colonial history, economy, and culture of Puerto Rico and the Puerto Rican People in a seminar course.

Trip stops included coastline areas where modern infrastructure such as roads, promenades, and houses are actively being undercut by rising sea level. Likewise, the spectacular indigenous petroglyphs at Cueva del Indio were also observed to be under threat from sea level rise. Lia Dirks ’27 summed it up as, “So many culturally and archaeologically significant sites are located near the shores, positioning them for coastal erosion. The citizens of Puerto Rico that we interacted with work endlessly to protect and educate the public on the importance of these sites.” As part of the trip, students also observed the various engineering solutions and adaptations used to mitigate coastal erosion, and the degree to which they are successful.

Students also went snorkeling along coral reefs and saw diverse tropical marine ecosystems that are impacted by warming oceans and include a variety of fish, corals, and echinoids. Indeed, some of the corals observed were bleached. Caedyn Wells ’25 said, “Seeing coral bleaching and climate change as a whole outside of documentaries was beyond eye opening. I will use this knowledge to educate myself and others when I return home.”

The group also met with journalist and Professor Rafael R. Diaz Torres, University of Puerto Rico, to learn about the island’s ongoing recovery from Hurricane Maria and the economic and political barriers that recovery efforts are encountering. Basil Nicol ’28 noted that “it was super interesting for me, a kid from the South Texas coast, to see the difference between recovery efforts in the continental U.S. and Puerto Rico after hurricanes.” Another student, Lilly McCully ’28, said that “It was incredible to speak with locals who discussed how the climate crisis not only affects their land but also their economy, and how prevalent the topic of climate change is in their everyday life.”

At El Yunque National Rainforest, students saw some of the rainforest recovery efforts from Hurricane Maria firsthand; Ella Aizeki ’25 observed that “seeing the destruction that Hurricane Maria caused in El Yunque rainforest was so eye opening to the extent of the devastation climate change can have not only on the people but on the island itself.”

In a fitting turn of events, a planned excursion to a bioluminescent bay was canceled at the last minute because a large mass of Sargassum, a brown macroalgae that has proliferated recently in the Atlantic Ocean and Caribbean Sea with warming temperatures, washed into the bay. The decay of the macroalgae used up most of the oxygen in the bay leading to a large fish die off that prevented safe kayaking. The effects of Sargassum inundations stretch well beyond the bioluminescent bay ecosystem. Sujie Yang ’28 noted that Sargassum causes “businesses alongside the coastlines to shut down, and the challenging political situations related to how islands collaborate on solutions to deal with incoming sargassum.”

The trip also included a visit to Castillo San Felipe del Morro National Monument, also known as El Morro, a fortress located in Old San Juan that first saw construction in the 16th century. Students learned how the fortress was built upon a rocky promontory to protect it from hurricanes. The calcite-cemented sandstone that underpins the fortress was deposited as predominantly wind-blown sand dunes in the Quaternary when global sea level was lower due to expanded ice sheets and the climate was cooler and drier. As sea level rises, these erosion-resistant sandstone cliffs make El Morro one of the least climate change susceptible features in San Juan.

This trip was generously funded by Vince ’68 and Deborah Sergi, the James Lockwood ’34 Fund, the Cynthia & Ray Wright Fund, and the new Richard C. Stenstrom Geology Field Trip Fund established by the Trust of Professor Richard “Dick” Stenstrom, Beloit College Class of ’58 and a respected emeritus professor of geology who taught at Beloit for 35 years, to fund field trips for Beloit College Students.

Group photo at Castillo San Felipe del Morro
Credit: Jorge Echevarria

Group photo at Cueva del Indio
Credit: Lia Dirks

 

Examining shoreline erosion, Playa Isla de Cabras
Credit: Sujie Yang Pointing out bleached corals, Balneario Playa Punta Salinas
Credit: Sujie Yang Shell deposit weathering along the shoreline
Credit: Sujie Yang Snorkeling at Balneario Playa Punta Salinas
Credit: Jay Zambito Hiking at El Yunque Rainforest
Credit: Jay Zambito