Coral reef condition:

A status report for

PUERTO 

RICO

2

0

20

FAIR

Data:

2

0

1

4–2017
why a status report?

Effective coral reef conservation cannot be accomplished 

without an informed and engaged public. This status report 

is part of an ongoing series to track the status and trends of 

coral reefs across the U.S. and its territories. The Puerto Rico 

coral reef status report is part of a larger effort to provide 

communities and decision-makers with information about 

managing and conserving coral reef ecosystems.

This status report provides a geographically specific 

assessment of Puerto Rico coral reef conditions for 

the period 2014–2017. Data were collected by NOAA’s 

National Coral Reef Monitoring Program (NCRMP). 

For more detailed information on methodologies, 

indicators, thresholds, and scoring, visit http://www.

coris.noaa.gov (keyword: status report).

what makes a coral reef?

1. One coral is 

made of many polyps 

Polyps are the basic building 

block for all coral colonies. They 

are small, colorful, and essential 

for corals to grow, eat, 

reproduce, and recover if 

ever injured.

3. Coral reefs 

provide food and 

shelter 

With small animals seeking shelter 

in the coral—and herbivorous fish 

keeping corals clean of nuisance 

algae—corals lie at the heart of a 

complex food web system that 

allows marine life to thrive 

in a coral reef.

2. Corals build 

coral reefs

Corals build their skeleton 

from calcium and carbonate in 

seawater. This skeleton not only 

gives corals their structure, but 

also provides the architecture 

for the coral reef overall.

Corals are living, ocean-dwelling animals. Each individual coral 

exists as a colony consisting of multiple small, identical coral 

polyps. Wherever corals make up the foundation of an underwater 

habitat, a coral reef occurs. Coral reefs are complex marine 

ecosystems that include diverse collections of colorful fish and 

other sea creatures. But what is it that allows corals to grow and 

support so much wildlife?

Zooxanthellae

(symbiotic algae)

anatomy of a Coral polyp

Nematocyst

(stinging cells)

Mouth

Tentacles

Digestive

sac

Calyx

(skeleton)
Reef-building corals provide the foundational architecture for coral reefs . These colorful reefs provide critical 

habitat to a variety of commercially and ecologically important marine fishes and invertebrates . The abundance of 

marine resources and beauty sustain local economies and enable eco-tourism . Their capacity to buffer 

intense wave energy during severe weather makes coral reefs critical to disaster preparedness as well. Despite 

their importance, coral reefs are subject to degradation via pollution runoff from land and overfishing . 

Warming water due to climate change also makes Puerto Rico's corals more vulnerable to bleaching .

coral reefs are important...

Coral reefs have the capacity to endure and recover 

from naturally-occurring climate-related events such as 

hurricanes, bleaching, and disease outbreaks. However, 

intensive human impacts have tested reef resilience. 

In Puerto Rico, deforestation, soil erosion, wastewater 

discharge, unsustainable fishing, pollution, recreational 

impacts, and seasonal natural disasters, have led to coral 

reef degradation. 

While small-scale artisanal fishing has long been a part 

of life in Puerto Rico, more recent overfishing of targeted 

species has hurt coral reefs. The decline of large predators 

and herbivorous fish, along with poor water quality, can 

contribute to increased macroalgae. Macroalgae compete 

with corals for space and sunlight. When highly abundant, 

macroalgae overrun corals, and alter ecosystem and food 

web dynamics. 

Warming waters due to climate change make corals more 

vulnerable to bleaching, a potentially lethal event where 

heat stress triggers corals to expel the zooxanthellae that 

provide their food. Degraded coral reefs are not as effective 

at protecting shorelines against hurricanes, nor can they 

adequately provide other ecosystem services, like habitat for 

fish and other animals.

Coral reefs are among the most diverse ecosystems 

on earth and home to a wide variety of fish and marine 

invertebrates. Reefs are built by colonies of tiny 

reef-building coral polyps (see figure, facing page). 

Each polyp contains thousands of symbiotic algae called 

zooxanthellae. These symbiotic algae provide corals with 

food by converting sunlight into sugar via photosynthesis. 

In turn, the corals provide shelter for zooxanthellae. Because 

sunlight is critical to this cooperation, many tropical coral 

reefs occur in shallow coastal waters (<30m depth). 

Coral reefs are an essential part of Puerto Rico’s marine 

ecosystem. They reduce the intensity of breaking waves, 

working alongside mangroves, dunes, and seagrass beds 

to protect the coastline. Other reef creatures, like sponges, 

provide ecological services such as filtering seawater, which 

reduces bacteria concentrations and keeps coastal waters 

around the island cleaner and clearer. 

Puerto Rico's reef fisheries are a significant economic and 

food resource, and coral reef-derived tourism generates 

nearly $2 billion in income and regional domestic product. 

There are broad social, environmental, and financial benefits 

of healthy coral reefs for Puerto Rico. If reefs aren't healthy, 

the repercussions could be devastating.

and they are under threat
The same reefs that protect the coast during a hurricane 

are also subject to storm damage themselves. In 2017, 

Hurricane Maria struck Puerto Rico's coral reefs with 

devastating force. After the storm passed, two teams of 

National Oceanic and Atmospheric Administration (NOAA) 

scientists and local partners went out to the reefs―one 

team to assess reef damage, and another to re-attach 

broken coral colonies. This effort focused on reefs that 

bore the greatest brunt of the storm. From February 

to June 2018, the teams surveyed over 86,000 corals 

and re-attached over 15,000 coral colonies. Restoration 

projects led by NOAA, the Puerto Rico Department of 

Natural and Environmental Resources, and other partners 

are ongoing. Restoring Puerto Rico's coral reefs promote 

both conservation and public safety. Healthy coral 

reefs can absorb up to 97% of oncoming wave energy, 

potentially reducing the impacts of storm surges and 

flooding during a hurricane. Rehabilitating Puerto Rico's 

damaged coral reefs is an important component of any 

future disaster readiness strategy.

restoring our reefs

On their own, reef-forming corals grow slowly. That's 

why in 2000, graduate students from the University of 

Puerto Rico received funding from the Sea Grant College 

Program to accelerate reef restoration using coral 

fragmentation. Living coral segments, fragmented from 

one individual, are capable of taking root and regenerating 

in the wild. The first project consisted of fragmenting 

staghorn corals (Acropora cervicornis) and transplanting 

segments to various reefs within La Parguera Natural 

Reserve. This approach to reef restoration has expanded 

into a network of coral nurseries in Puerto Rico, where 

dedicated teams cultivate juvenile corals before planting 

them on a reef. The nurseries are operated by public 

agencies, private enterprises, and nongovernmental 

organizations. So far, over 100,000 farmed corals have 

been planted to increase coral populations on Puerto 

Rico's reefs. Because juvenile mortality for farmed corals 

has been low in the wild, coral nurseries have helped 

reefs recover more quickly from both human impacts and 

natural disasters. This restoration also helps preserve the 

ecological services that coral reefs provide to Puerto Rico.

A submerged nursery of growing corals (top). A diver 

assesses recently planted corals (bottom). Photos: 

Hector Ruiz for HJR Reefscaping.

preparing for the next hurricane

Scattered corals broken by 2017 hurricanes (left). A coral colony is reattached to the reef with cement (right). 

Photos: NOAA.
CORAL REEFS IN PUERTO RICO ARE IN FAIR CONDITION

puerto rico

Puerto Rico is an archipelago of islands in the Greater 

Antilles, located in the north central Caribbean between the 

U.S. Virgin Islands to the east and the island of Hispaniola to 

the west. In addition to the main island, the islands of Mona, 

Monito, Desecheo, Caja de Muertos, Vieques, and Culebra 

make up the Commonwealth of Puerto Rico. The main island 

has a linear coastline of 620 km (385 mi), surrounded by 

over 5,000 km2 (1930 mi2) of shallow coral reef ecosystems. 

Colonized by Spain in the early 1500's, it became a U.S. 

territory in 1898.

Puerto Rico's coral reef condition was evaluated under 

four categories—corals & algae, fish, climate, and human 

connections (see Key Themes & Indicators for descriptions). 

Puerto Rico's coral reefs are in fair condition overall. Corals 

& algae are moderately impacted to very impacted. Fish 

are moderately to severely impacted. Diversity of fish 

populations is in critical condition. Climate is also a factor 

negatively affecting coral reefs. Ocean acidification is a 

global problem with regional impacts occurring in the 

Caribbean. However, temperature stress from warming 

waters is not as bad in Puerto Rico compared to other 

jurisdictions for the time period assessed. Island-wide 

surveys show that while support for management actions is 

very good, pro-environmental behavior and awareness are 

critical and impaired, respectively. More work needs to be 

done to both raise awareness and improve personal actions 

that protect and restore coral reefs. The coral reefs of Puerto 

Rico experience moderate impacts from human activities 

and development and are struggling against threats such as 

pollution, overfishing, and global climate change.

Adult coral

Adult coral

Herbivory

Mortality

Diversity

Coral Cover

Macroalgae

CCA Cover

FIS

H

CORALS

& ALGAE

CL

MI ATE

C

HUMAN ONNECTIONS

Temperature Stress

Ocean

acidification

Reef material

growth

Diversity

Reef fish

Sustainability

Awareness

 Pro-environmental

behaviors

management

Support for

actions

T

70

A good reference area is a vital component of the NCRMP status report process. It is the area (or specific years and 

area) that all biological samples are compared against. The ideal reference area would be one that is large enough in 

spatial scale to encompass representative habitats and depths. It would also have sufficient sampling and be an area 

that is unaffected by anthropogenic forces like fishing pressure, and land based sources of pollution. Most often, a region 

does not have an ideal reference area, and we must instead choose the best possible area given the circumstances. In 

Puerto Rico, three separate smaller areas were initially chosen as the fish reference based on local stakeholder and 

expert opinion. Mona, Desecheo, and the western portion of La Parguera were thought to be the best possible reference 

areas; however, after our initial analysis of the data, it was clear that these areas were too impacted and could not 

represent the best possible reference area on their own for Puerto Rico's fish communities. To optimize the reference 

area for this status report, two federal national parks located in the U.S. Virgin Islands were included: Buck Island Reef 

National Monument in St. Croix and the Virgin Islands Coral Reef National Monument in St. John. Together, the five areas 

combined better represent a reference area to evaluate the fish communities of Puerto Rico.

What do the scores mean?

80–89% Good

Most indicators meet reference values. 

Conditions in these locations are lightly 

impacted or have lightly declined. Human 

connections are high.

70–79% Fair

Some indicators meet reference values. 

Conditions in these locations are moderately 

impacted or have declined moderately. Human 

connections are moderate.

All or almost all indicators meet reference values. 

Conditions in these locations are unimpacted, or 

minimally impacted or have not declined. Human 

connections are very high.

90–100% Very Good

60–69% Impaired

Few indicators meet reference values. 

Conditions in these locations are very impacted 

or have declined considerably. Human 

connections are lacking.

0–59% Critical

Very few or no indicators meet reference values. 

Conditions in these locations are severely 

impacted or have declined substantially. Human 

connections are severely lacking.

Insufficient Data

Not scored.
Marine Protected Areas (MPAs) are designated marine 

regions with set geographical boundaries designed to 

conserve marine life and critical ecosystem services. The 

level of protection depends on an MPA’s designation status. 

Some MPAs are Natural Reserves, where multiple activities 

are permitted, while others are Marine Reserves, where 

all resource extraction is prohibited either seasonally or 

year-round. Puerto Rico has approximately 30 MPAs. For 

example, the Desecheo Island Marine Reserve is a small 

no-take MPA that sustains some of the best-developed 

nearshore and deep water coral reefs in Puerto Rico.

MPAs play a critical role in Puerto Rico’s Coral Reef 

Monitoring Program. Since 1999, the program has surveyed 

reefs with high coral cover to detect changes in benthic 

and fish communities over time. Since 2015, 42 coral reef 

stations have been surveyed biannually, 26 of which are 

within designated MPAs. The most recent data show an 

average coral cover of 23% within and 25% outside of MPAs. 

Long-term PRCRMP data indicate that a massive 2005 coral 

bleaching event was a pivotal moment of change for Puerto 

Rican coral reefs. By 2006, live coral cover at 14 monitoring 

stations had declined by an average of 40%. Within the 

Desecheo Island Marine Reserve, live coral cover declined 

by as much as 53%. At Mona and Monito Islands Natural 

Reserve, Puerto Rico’s largest MPA, coral cover fell by 63%. 

A few sites have seen some recovery in live coral coverage; 

however, most PRCRMP sites have not rebounded to pre2005 levels. 

tracking long-term 

changes to coral cover

32%

41%

31%

19% 18%

11%

0

10

20

30

40

50

Other Stations 

(N=9)

Isla Desecheo 

(N=3)

Isla Mona 

(N=2)

Mean Coral Cover Losses (%)

Coral loss from 2005 bleaching event

Pre-2005 Post-2005

Across at least 14 PCRMP monitoring stations, coral 

cover declined after the 2005 bleaching event. 

Data from DNER PRCRMP [1999-2009 subset].

key themes &indicators

Climate

Climate affects all components of a reef 

system. Climate change and ocean acidification 

influence reefs across the globe, but conditions 

vary at the regional and local level. The climate 

indicators are:

• Temperature stress, which evaluates the frequency and 

severity of high temperature events.

• Ocean acidification, which indicates if the water 

chemistry is suitable for the growth of corals 

and other calcifiers.

• Reef material growth, which is a calculated 

measurement of the yearly gain or loss of 

three-dimensional reef habitat. 

fish

Coral reefs serve a vital ecological role for fish 

species. Fish are important to the ecology of the 

reef, the economy, and the livelihoods of local 

communities. The indicators for fish are:

• Reef fish, a region-specific measure of density for 

selected fish species.

• Sustainability, a measure of human-related fish 

mortality relative to natural fish mortality.

• Diversity, a measure of unique fish species present.

Coral reef management agencies protect reef 

resources through management plans, public 

education, and involving communities in 

managing their resources. The indicators for 

human connections are:

• Awareness, an indicator of residents’ familiarity with 

threats to and the importance of reefs.

• Support for management actions, an indicator of 

support for reef management activities.

• Pro-environmental behavior, an indicator of residents’ 

participation in activities to protect the environment.

human connections

Corals & algae make up the base of the coral 

reef ecosystem, providing food and shelter 

for fish, shellfish, and marine mammals. The 

indicators for corals & algae are: 

• Coral cover, a measure of what percentage of the 

bottom (benthos) is living stony coral.

• Macroalgae cover, a measure of what percentage of 

the bottom (benthos) is macroalgae.

• Crustose coralline algae (CCA) cover, a measure of 

what percentage of the bottom (benthos) is crustose 

coralline algae.

• Adult coral, a measure of the density of reproductive 

age coral species. 

• Herbivory, a measure of the level of grazing pressure by 

fish on corals and algae.

• Mortality, a measure of the amount of old dead coral 

skeleton exposed as scars on live coral colonies.

• Diversity, a measure of unique coral species present.

Corals & algae
Status report working group

Antares Alvarez, Eileen Alicea, Helena Antoun, Jeremiah 

Blondeau, Ernesto Diaz, Caroline Donovan, Kimberly 

Edwards, Peter Edwards, Ian Enochs, Tania Metz Estrella, 

Chloe Fleming, Nate Formel, Reni Garcia, Erick Geiger, 

Matt Gorstein, Melissa Gonzalez, Sean Griffin, Jay Grove, 

Sarah Groves, Miguel Figuerola Hernandez, Matthew 

Johnson, Chris Jeffrey, Aurora Justiniano-Santos, Heath 

Kelsey, Nilda Jimenez Marrero, Derek Manzello, Nathan 

Miller, Michael Nemeth, Hector Ruiz, Jorge Sabater, Erica 

Towle, Orian Tzadik, Michelle Schärer-Umpierre, Shay 

Viehman, Ernesto Weil, and Stacey Williams.

About this status report

This status report is a joint product of NOAA's Coral 

Reef Conservation Program (CRCP) and the University 

of Maryland Center for Environmental Science. Science 

communication, design, and layout by Nathan Miller, 

Caroline Donovan, Heath Kelsey, and Max Hermanson. 

March 2020.

Acknowledgements

The CRCP supports effective management and sound 

science to preserve, sustain, and restore valuable 

coral reef ecosystems for future generations. For 

healthy corals enrich life 

in puerto rico

more information, visit coralreef.noaa.gov. Cover 

photographed at Mona and Monito Islands Natural 

Reserve in April 2012 by JP Zegarra.

The views and conclusions contained in this document 

are those of the authors and should not be interpreted 

as representing the opinions or policies of the U.S. 

Government or the National Fish and Wildlife Foundation 

and its funding sources. Mention of trade names 

or commercial products does not constitute their 

endorsement by the U.S. Government, or the National 

Fish and Wildlife Foundation or its funding sources.

References

F. Ferrario, M.W. Beck, C.D. Storlazzi, F. Micheli, C.C. 

Shepard, and L. Airoldi. (2014). "The effectiveness of coral 

reef for coastal hazard risk reduction and adaptation," 

Nature Communications, doi: 10.1038/ncomms4794.

V.R. Leeworthy, D. Schwarzmann, S. Hughes, J. Vaughn, 

C. Dato, and G. Padilla. (2018). Economic Contribution of 

Reef Using Visitor Spending to the Puerto Rican Economy. 

Silver Spring, MD: Office of National Marine Sanctuaries, 

National Oceanic and Atmospheric Administration.

Puerto Rico Department of Natural and Environmental 

Resources (2019). Puerto Rico Long-Term Coral 

Reef Monitoring Program database compilation:

The status report working group during the workshop in 

San Juan, Puerto Rico, May 2019.

what you can do to help

There are many threats to coral reefs. Here are a few 

actions YOU can take to help conserve coral reefs:

People living in Puerto Rico have a diversity of livelihoods 

and experiences, which depend on the benefits provided 

by healthy coral reef systems. The beaches and coral reefs 

of the offshore islands, including Culebra, Vieques, Caja de 

Muertos, Mona, and Desecheo, attract divers, snorkelers, and 

boaters from around the world. Marine tourism generates 

an important source of employment and income for dive 

operators, tour boats, marinas, fishing charters, and the 

service industry, all of which support the regional economy. 

White sands in areas such as Flamenco Beach in Culebra 

are made of fine grain sands produced by sea urchins and 

parrotfishes that graze on the algae of coral reefs. 

Cities and towns such as San Juan in the northeast and La 

Parguera in the southwest are protected from swells and 

storm impacts by nearshore, shallow reefs. Tourists flock 

to the shores of Aguadilla and Rincón to experience the 

renowned surf breaks that occur when oncoming swells 

crest over nearshore coral reefs. Many fishing ports such as 

Puerto Real, La Parguera, Peñuelas, Guayama, Naguabo and 

others have historically depended on sales of fresh seafood 

caught in extensive areas of shallow coral reef habitat.

A reef scene at Desecheo Island Marine Reserve. 

Photo: JP Zegarra.

Obey all natural reserve regulations, and 

do not drop your anchor in reef areas. 

Instead, use designated mooring buoys, 

or drop anchor on sandy bottom areas.

Only catch enough fish for you and your 

family. If you don't fish, choose seafood 

that is sustainably harvested.

Pick up your own trash and the trash 

that others have left behind.

Support initiatives that protect and 

preserve coral reefs.

Educate yourself about coral reefs and 

the creatures they support.

Don’t stand on or touch live coral. Don't 

take pieces of corals home with you.

Participate in volunteer-based/citizen 

science initiatives aimed at 

coral conservation.

Be responsible for the fishing nets and 

other gear you use.

substrate cover percent, octocoral colony counts, 

macro invertebrate densities, fish densities, and fish 

biomass from 1999 to 2018 (NCEI Accession 0204647).

PRCRMP benthic-sessile data 1999-2018. NOAA 

National Centers for Environmental Information. Dataset. 

https://accession.nodc.noaa.gov/0204647. Accessed 

December 3, 2019.