Meet Nikita Sridhar

Bio

My name is Nikita Sridhar and I am a rising senior at UCLA with a major in Marine Biology and minor in GIS&T. At UCLA, I work on the utilization of eDNA to assess the health of Marine Protected Areas. I am most interested in studying the effects of anthropogenic stressors on the resiliency of marine communities. This summCoral nurseries are an effective tool for preserving reef ecosystem health from climate change impacts and regional stressors.  To maximize the performance of nurseries, practitioners have historically calculated growth data on corals within nurseries by measuring linear extension with rulers and tapes, which can only document change over time on a single dimension/plane, or resort to removing the coral from the water to obtain metrics like volume or surface area.  The goal of this project is to develop a Standard Operating Procedure (SOP) using 3D photogrammetry as a suitable methodology for analyzing the growth of coral fragments in coral nurseries, by examining a suite of corals currently growing in a coral nursery on Saipan, CNMI.  Photogrammetry enables 3D models of coral fragments to be generated in order to derive volume and surface area data on the accretion of complex carbonate structures.  Proper objective data on growth rates, when paired with environmental data within the nursery or from parent colony collection sites, may also help determine which fragments recover better based on current, temperature, and depth within the nursery.  Gaining a better understanding of coral growth within 3 dimensions has the potential to better inform conservation decisions and contribute to the preservation of reef ecosystems.silient to change, just like the corals we are studying!

Abstract

This project aids the restoration efforts of CNMI by quantifying the wound healing rates of Acropora pulchra/aspera, Acropora muricata, and Acropora globiceps. Previous studies have found that in response to non-lethal stress events, such as physical obtrusions, corals can expedite growth in order to facilitate their recovery. Additionally, CNMI experiences a high frequency of storm events, during which physical obtrusions to corals have been documented for a wide range of species including lagoonal staghorn Acropora sp. which use this type of fragmentation as a reproduction strategy. Monitoring the process of coral wound healing using quantitative metrics such as the rate of change in wound area and qualitative metrics such as the time taken for the wound to be completely covered in flesh, fully integrated with zooxanthellae, and show polyps and apical tips will help us understand how corals repair the damage incurred. Last year, a coral nursery was constructed in CNMI using fragments collected from healthy wild parent colonies that had demonstrated some level of resistance to thermal stress. This year, physical damage was generated as part of the propagation of corals within the nursery and photographed. The images taken of the area were processed using ImageJ software to construct a time series of measurements for the different species of corals. The focus of this project is to conduct a quantitative and qualitative analysis of coral wound healing and also to create a Standard Operating Procedure to improve the accuracy of wound healing measurements for future use. In doing so, we can adjust restoration efforts at CNMI by choosing faster recovering species to improve overall nursery and outplant performance.