Project: CAREER: Charting the zoogeochemistry of coral reef ecosystems through an integrative structure-to-function framework

Earth's ecosystems are characterized by the steady exchange of vital elements among plants, animals, microbes, and their surrounding environment. These fluxes represent the pulse of our planet, but they are inherently difficult to observe in real time. In fact, in some systems, such as tropical coral reefs, the presence of hundreds of species on a single reef creates a maze of pathways along which critically important elements –such as carbon, nitrogen, and other less abundant nutrients– can flow. Yet, as human activities continue to reshape the structure and composition of ecological communities globally, understanding these dynamics is becoming increasingly important, especially for systems that provide important resources to human societies. This program investigates the origin and movement of elements on tropical coral reefs by combining detailed field surveys of reef fish communities with complementary laboratory analyses and modeling frameworks. Specifically, the research aims to uncover where, when, and why certain organisms emerge as key players for the pulse of coral reef ecosystems, how this may be affected by the global degradation of coral reefs and their structural architecture, and how these changes may impact the nutrients that coral reefs can provide to humans. The program leverages the resulting data and resources to 1) implement K-12 lesson plans and a research mentoring program with local schools in South Texas, 2) develop a graduate course module and a visiting scholars program for Belizean students, and 3) craft an informational fiction children’s book centered around the diversity of life on coral reefs.

The movement of elements through organismal communities is the pulse of Earth’s ecosystems. However, due to the dynamic nature of processes such as growth, excretion, or predation, this pulse is inherently difficult to monitor. 'Structure-to-function' frameworks, in which organismal traits are superimposed on communities to predict ecosystem-scale processes, have yielded great insights into the functioning of many ecosystems. On coral reefs, however, unparalleled ecological complexity has long obscured the dominant elemental pathways that underpin the iconic productivity of reef fish communities. As coral reefs are rapidly declining, our time to understand the pulse of reefs is swiftly running out. The proposed project seeks to chart the ‘zoogeochemistry’ of coral reefs –i.e., the movement of elements through reef fish communities– using a new, integrative structure-to-function framework. Specifically, the program aims to: 1) uncover the origin and flow of carbon, nitrogen, and phosphorus through reef fish communities by combining comprehensive field surveys across the Belizean Barrier Reef with estimates of species-specific resource use (via compound-specific isotope analyses), biomass production (via demographic models), and nutrient exchange (via bioenergetic models); 2) reveal relationships between benthic structural complexity and elemental fluxes across scales; and 3) predict how the degradation of benthic complexity and its effect on reef zoogeochemistry influence the productivity and micronutrient yield of Caribbean fisheries species. The project leverages this research to bolster a cross-scale education program that consists of a K-12 lesson plan and mentoring program in Corpus Christi (local impact), a hands-on graduate course module and visiting scholars program for Belizean students at UT Austin (regional impact), and an informational fiction children's book that uses the diversity of life on reefs to examine how acceptance of others may require us to move beyond our own lived experiences (global impact).