Serrano, Xaymara; Baker, Andrew; Miller, Margaret

Final Report - Effects of sedimentation stress in adult and early life stages of corals, including two ESA-listed species (POR-2016-16 FINAL REPORT)

2019

NOAA/OAR/Atlantic Oceanographic and Meteorological Laboratory

I. Experiments and preliminary analyses All experiments were carried out at the Marine Technology and Life Science Seawater (MTLSS) complex at the University of Miami's Rosenstiel School (RSMAS). Two different sets of experiments were conducted, as follows: Effects of sedimentation on larval performance: O. faveolata larval experiments were completed in the fall of 2017 as described in the POR 2015-15 Final Report (note that there were insufficient larvae from Acropora palmata for proposed experiments due to poor fertilization rates). Overall, findings suggest that the success of early life stages of O. faveolata may be compromised by the presence of PortMiami sediments during the pelagic phase. In addition, findings suggest both short- and long-term effects of sedimentation, as effects were still observed after corals were allowed to recover for 1 week (see POR 2015-15 Final Report). Together, these findings provide empirical data to local managers that might support the implementation of environmental policies aimed at minimizing the impacts of dredging operations, especially during expected coral reproductive seasons. Effects of sedimentation on adult corals: Experiments were completed in the fall of 2017 and data is currently being analyzed (see POR 2016-16 Interim Report). Because of Hurricane Irma many of the Acropora cervicornis genotypes we intended to use in our experiments were no longer available, so experiments were conducted using S. siderea and P. astreoides. Preliminary analyses suggest species-specific effects of finegrained sedimentation on adult coral respiration. Significant decreases in respiration were observed for S. siderea exposed to sediments collected near PortMiami (compared to those exposed to reef sediments), but no effects were observed for P. astreoides (see POR 2016-16 Interim Report). These findings are consistent with other work which suggests that Florida's "weedy" species may be more resistant to anthropogenic stressors compared to broadcast spawning species (e.g., Lirman et al. 2003). In addition, a comparison of the data obtained from the adult and larval experiments suggests that early life stages of corals may more susceptible to the effects of sedimentation stress, consistent with previous literature (e.g., Fabricius, 2005; Jones et al. 2015). II. Sediment sample collections and microbial analyses Sediment samples were collected in 2016-2017 with permits from the FKNMS and Florida DEP at three different sites in SE Florida relevant to our experimental treatments: (1) PortMiami sediments, collected from a site 200 m north of the dredged channel ("Linear Reef" reported by Miller et al. 2016 as having detrimental effects on corals monitored and highest sediment depth measurements); (2) Emerald reef in Miami (from where adult experimental corals from the species S. siderea and P. astreoides were collected); and (3) Horseshoe reef in Key Largo (from where O. faveolata gametes were collected). Sediment samples were collected from the first 10 cm of the sediment layer in triplicate and ~1 g of each was preserved in RNAlater for Microbial Source Tracking (MST) assays and 16S amplicon sequencing. Note that MST markers look at rare members of the microbial community (using quantitative PCR) compared to 16S amplicon sequencing (which looks at the most abundant types of bacteria).

sedimentation, life stages, coral, ESA-listed Species, O. faveolata, Florida

FY2017; CRCP Project ID: 31147; Project Title: Effects of sedimentation stress in adult and early life stages of corals, including two ESA listed species; Principal Investigator: Xaymara Serrano