Characterization of the associated

microorganisms of Thalassia

testudinum as an indicator of sea grass

ecosystem health in Puerto Rico

By:

Manoj Saxena

Laura L Fidalgo

Ingrid Venero Vélez

Coastal Environments

Loretta Roberson, Ph.D.

Introduction

SEA GRASS ECOSYSTEMS

Primary producer

Important for nutrient cycling

Habitats of many other species

Bio indicators of environmental conditions

Sea Grass- microbes

interaction

Global map indicating changes in sea grass area plotted by coastline regions.

Waycott M et al. PNAS 2009;106:12377-12381

©2009 by National Academy of Sciences

Sea Grass Ecosystems are under threat

RED = Rapidly decreasing

Goals and Objectives

Hypothesis: Fecal pollution has an impact on the composition and diversity of the epiphytic microorganisms on Thalassia testudinum leaves effecting its growth.

Specific objectives: a) Characterize the composition and diversity of Thalassia testudinum associated microorganisms in three different sites that range from minimal to heavy contamination. b) Evaluate the relation between degree of fecal pollution and concentration of epiphytic coliform bacteria.

c) Evaluate the biological productivity of Thalassia testudinum in each study site.

Methodology Study sites

Water quality gradient along San Juan Estuary (PEBSJ)

Condado Lagoon (B +quality)

San Juan Bay (B quality)

San Jose (C quality)

Control area: Jobos Bay (Natural Pristine System)

Methodology

Sea grass productivity Data Source Morphometry of blades - Leaf

Area Index (LAI) Standing Crop Biomass - Blade

production and turnover.

Analysis

Turnover will be calculated by dividing standing crop by production value.

Microbial community structure

Data Source DNA from epiphytic microbial

communities on Thalassia leaves Sequencing – Meta genomics

Analysis

Dendrogram cluster analysis- comparison

of microorganism community

composition by sea grass bed area

Methodology

A

Results and Potential Benefits

Direct Defines microbial community of sea grass Thalassia testudinum

Pollution effects on microbiota composition

Knowledge of new plant- microbe interactions

Bio-indicator

Indirect Opens new research areas

Potential discovery of new microbes species

Questions

Reference

Celdrán, D., Espinosa, E., Sánchez-Amat, A., & Marín, A. (2012). Effects of

epibiotic bacteria on leaf growth and epiphytes of the seagrass posidonia

oceanica. Marine Ecology Progress Series, 456, 21-27. doi:

10.3354/meps09672

Merina, M., Lipton , A. P., & Godwin Wesley, S. (2011). Isolation,

characterization and growth response of biofilm forming bacteria bacillus

pumilus from the sea grass, halodule pinifolia off kanyakumari coast. Indian

Journal of Marine Sciences, 40(3), 443-448.

Mass mortality of the tropical seagrass Thalassia testudinum

in Florida Bay (USA) MARINE ECOLOGY PROGRESS SERIES, Vol. 71:

297-299, 1991

Waycott M, et al. Accelerating loss of seagrasses across the globe threatens

coastal ecosystems. Proc Natl Acad Sci USA 2009;106:12377–12381

Teena S. Michael, et al. A review of epiphyte community development:

Surface interactions and settlement on seagrass,Journal of Environmental

Biology, July 2008, 29(4) 629-638 (2008)

Activity Year 1 Year 2 Semester 1 Semester 2 Semester 1 Semester2

Sampling of sea

grass leaves X

Water sampling X Water quality

analysis X

DNA extraction

from sea grass

samples

X

PCR

amplification X

Sequencing X Statistical

Analysis X X

Writing

Manuscript X

Time table