University of Puerto Rico, Rio Piedras Campus. Environmental Science Department. Coastal Environment Course.

1. DEVELOPING A MANGROVE
MONITORING PROGRAM FOR THE
SAN JUAN BAY ESTUARY
October 14, 2013
Christopher Nytch, Osé Pauléus, Chao Wang

2. Mangroves in Puerto Rico
estuario.org
Martinuzzi et al. 2009

3. Importance of mangroves

Habitat for fish,
shrimp, crabs and
marine invertebrates

Foraging, roosting
nesting sites for birds
and reptiles
www.nzdl.org

Ecosystem services




Timber for homes & fuel
Food
Protection from storm impacts, coastal
erosion
Spiritual and recreational experiences
www.puerto-rico-tourism.com

4. Changes in mangrove cover in PR
Extent of the mangrove cover in Puerto Rico, including the four historical periods of change (between
parenthesis). Original estimates for the years 1968, 1971, 1972, and 1974 (white diamonds) where
averaged and combined into one single value for 1971. Data for other years is showed in black squares.
Source: Martinuzzi et al. 2009.

Mangroves currently cover 8,700 ha (1%) of Puerto Rico

5. Changes in mangrove cover in PR
Maps showing 1) mangroves within the San Juan Metropolitan Area (i.e., urban sites); in this area, Caño
Martín Peña (site „„a‟‟ in the lower image) increased in mangrove forest cover between 1977 and 2002 due
to restoration efforts, while Rio Puerto Nuevo (site „„b‟‟) decreased. Inset 2) shows an urban–rural
site, which decreased in forest cover, and inset 3) correspond to a rural site, which increased. Source:
Martinuzzi et al. 2009.

6. Forces of mangrove loss and gain
Martinuzzi et al. 2009
80grados.net
estuario.org

7. Mangrove Protection




1972 “organic” law creates DRNA and protects
mangroves anywhere they occur in PR
Twenty-five additional state and nine federal laws
and regulations protect mangroves (Torres
Rodríguez 1994)
Since the 1970s, overall mangroves have
expanded throughout coastal areas, inside and
outside reserves, in rural areas, and in some
developed landscapes (Martinuzzi et al. 2009)
Active restoration in some sites

Caño Martín Peña

8. Ongoing Threats

The legal approach has not prevented negative effects of
human decisions and activities related to mangroves

While the area of mangroves has increased over the last
decades for the entire island, it has decreased in certain sites
PRCCC 2013

Threats (Lugo 1988, Martinuzzi et al.
2009, Miller and Lugo 2009)






Coastal development
Fragmentation from roads
Pollution, sediment and
nutrient runoff
Uncontrolled recreation
Natural
disturbance, (e.g., hurricanes)
Projected rises in sea level

9. Research Problem


We know:
 How human activities and land use change patterns
have affected mangroves over the past 200 years
What‟s lacking:
 Detailed monitoring of mangrove habitats and current
patterns of change in response to various threat
factors and conservation activities

In order to improve future management and zoning
regulations

10. Research Goal

Develop a multi-scale monitoring program in the
San Juan Bay Estuary (SJBE), as a pilot project
to track fine-scale changes in the spatial extent
and structure of mangrove habitats over time in
response to natural and human-induced
processes.

Similar to the water quality monitoring project
already underway

11. Objectives

1) Map the current distribution and extent of mangroves (per type) in the
SJBE;

2) Document fine-scale changes in SJBE mangrove distribution, extent and
forest structure (mangrove type) from 2001-present;

3) Calculate the rate of increase or decrease since 2001 in mangrove
patches within the SJBE;

4) Assess mangrove changes in relation to urban
development, access, and species type;

5) Collaborate with the SJBE to develop a protocol for regular monitoring of
mangrove at multiple scales using remote sensing techniques and citizen
science methods;

6) Establish a series of monitoring points throughout the SJBE to carry out
long-term observational studies of mangrove dynamics;

7) Implement the monitoring program with the aid of SJBE Program citizen
scientists to collect initial data;

8) Evaluate the results and effectiveness of the monitoring program.

12. Hypotheses

Based on mapping and habitat analysis from 20012013:

1) The rate of change of mangrove cover has remained
constant.

2) Changes in mangrove cover are dependent on location.


2a. Proximity to urban areas and roads is positively correlated
with mangrove reduction.
3) Changes in mangrove cover affect species differentially.

3a. Mangrove forest structure is changing with some species
gaining and others losing.

13. Study Site: San Juan Bay Estuary




160 bird species
124 fish species
19 species of reptiles/
amphibians
300 species of wetland
plants

Mangroves

estuario.org



3,400 acres / 1,376 ha
80% urbanized
>8,300 persons/mi2

1/3 of all remaining
mangroves in PR
6 sites






Piñones State Forest
Suarez Canal
Caño Martín Peña
San Juan Bay
San Jose Lagoon
Condado Lagoon

14. Methodology I – baseline analysis
To be carried out by the research team

Mapping of current mangrove land cover and changes from
2001-2013

Quickbird satellite imagery



Spatial analysis (ArcGIS) to interpret mangrove species distribution
and extent
Evaluation of image interpretation from field visits
Analysis of changes in mangrove cover at all six sites

Location


Urban proximity
Roads proximity


Logistic regression
Species patterns

Relative abundance of black vs. red vs. white vs. button mangroves

ANOVA

15. Methodology II – monitoring program
Together with the SJBE Program:

Discuss monitoring priorities and objectives:

Assessment examples

Rise in sea level






1) Loss of mangroves due to erosion of seaward margin
2) Relocation and migration of mangroves inland
3) Change in mangrove forest structure, such as landward
replacement of black by red mangrove
Water quality & pollution
Excessive recreation
Fragmentation
Develop monitoring criteria
 Develop monitoring protocol

Remote sensing techniques
 Field data collection
 Decide on monitoring frequency


Example: 2x / year– wet and dry season

16. Methodology II (cont.)
Together with the SJBE Program:



Establish long-term monitoring points
Organize local community volunteers and materials
Implement monitoring and collect initial data (1-year) in
collaboration with SJBE




scientists
SJBE program citizen scientists
Evaluate monitoring program success and
recommendations
Report results



Official report
Community forum
Education materials

17. Potential benefits





Provide a systematic procedure for collecting detailed
data about patterns and processes of mangrove change
through time.
Better inform natural resource managers involved in
conservation planning/design and restoration.
Generate public awareness about the importance of
mangroves and their risk factors.
Build collaborative management relationships among
residents, the SJBE Program, and the DRNA.
Test-drive a pilot monitoring project that could be
expanded island-wide.

18. Activities & Timeline
Month 1
Month 6
Month 12
Month 18
Month 24
Mangrove analysis &
mapping
Discuss & Develop monitoring
criteria
Develop monitoring protocol & Establish monitoring
points
Organize local community
volunteers
& monitoring materials
Implement monitoring & collect initial
data
Evaluate program & final
report

19. Budget

20. References

Lugo, A. 1988. Estimating reductions in the diversity of tropical
forest species. Pp. 58-70 in E.O. Wilson (Ed.), Biodiversity. National
Academy Press, Washington, D.C.

Martinuzzi, S., W.A. Gould, A.E. Lugo, and E. Medina. 2009.
Conversion and recovery of Puerto Rican mangroves: 200 years of
change. Forest Ecology and Management. 257:75-84.

Miller, G.L. and A.E. Lugo. 2009. Guide to the ecological systems of
Puerto Rico. Gen. Tech. Rep. IITF-GTR-35. San Juan, PR: U.S.
Department of Agriculture, Forest Service, International Institute of
Tropical Forestry. 437 pp.

Torres Rodríguez, M., 1994. Plan de manejo para los manglares de
Puerto Rico. Estado Libre Asociado de Puerto Rico. Departamento
de Recursos Naturales y Ambientales, San Juan, PR.