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BAHAMAS
CORAL REEF REPORT CARD
Volume 2: 2015-2019
Andros, Abaco, Grand Bahama, New Providence & Rose Island, Bimini, Eleuthera,
Exumas, Cat Island, Cocneption Island, Long Island
©Paul Selvaggio/SECORE Intn’l/Pittsburgh Zoo
TABLE OF CONTENTS EXECUTIVE SUMMARY
Coral reefs are home to the greatest diversity of life in the Bahamian
Executive Summary .................................1
archipelago and provide critical ecosystem services that support a
Introduction to Indicators .........................2 vibrant economy, including tourism, fisheries and protection from coastal
erosion. These reefs owe much of their value to the corals themselves, which
Evaluating Reef Health ............................3 are the architects and engineers of the reef, building reef structure that protects
Benthic Index .........................................4
shorelines and provides habitat to marine life. Despite their inherent value for
the ecology and economy of The Bahamas, coral reefs here have dramatically
Coral Condition Index .............................6 declined over the last 50 years as corals have been faced with increased threats
that have local, national, regional and global impacts. The reduction of key
Coral Disease Index .................................8 species due to disease, fishing, and habitat loss have altered the function of
Coral Recruitment Index ........................10 marine ecosystems, weakening the resilience of coral reefs and preventing their
recovery from hurricanes, bleaching events and damage from other threats.
Large Parrotfish Index ............................12
The first steps to helping reefs recover is to assess their status; see how various
Grouper Index ......................................14
threats have led to declines; and how protection and restoration can reduce or
©Paul Selvaggio/SECORE Intn’l/Pittsburgh Zoo even reverse the decline of coral reefs. This report card examines these factors
Bahamian Reef Health Index ..............16
Coral reefs provide a crucial source of food and for Bahamian coral reefs over the past 5 years, from 2015 to 2019. When
Threats income for people around the world. possible we compare current data with past information from the previous coral
Hurricanes ........................................22 reef report card to see how reefs have changed over the past 5-10 years. While
Coastal Development ............................24 this report card really just scratches the surface regarding coral reef health in
The Bahamas, we believe it provides a good overview to inform management
Coral Bleaching ..................................26 decisions in a way that is accessible to experts and non-experts alike.
Stony Coral Tissue Loss Disease ............28
Unregulated Fishing .............................30
Successes
Coral Restoration ...............................32
Exuma Cays Land & Sea Park ..............34
Balancing Protection & Development...36
How Can I Help? ...............................38
Acknowledgements ...............Back Cover
ON THE COVER
Photo of a coral reef at John Miller’s Blue Hole.
© Kevin Davidson
© Paul Selvaggio/SECORE Intn’l/Pittsburgh Zoo Coral reefs are home to the highest biodiversity in
The Bahamas. Perry Institute for Marine Science Executive Director, Dr. Craig Dahlgren, conducting a fish survey.
i
INTRODUCTION TO INDICATORS EVALUATING REEF HEALTH
To better manage and protect Bahamian coral reefs, we must first understand how Grading Scale
reef condition varies over space, time and under different threat levels. For the past
decade, we have assessed the health of reefs throughout The Bahamas using Atlantic
and Gulf Rapid Reef Assessment (AGRRA) protocols, and have analyzed the data 1 2.5–3
Benthic Index 1.5–2 3.5-4
to look at specific indices of reef health, grading reef health on a scale from poor to
good for each index and for a combined Bahamian Reef Health Index (BRHI). We Coral Condition (% alive)
also present case studies to: 1) show the impact of various threats to coral reef health, Coral Disease (% colonies) >5 5–2.5 < 2.5 0
2) highlight some of the strategies that have proven successful to improve reef health,
Recruit Density (no./m2)
and 3) inform some of the challenges facing The Bahamas moving forward.
Measures of Coral Reef Health Large Parrotfish Biomass (g/100m2) 0–500 501–1000 1001–500 >1500
Benthic Index Grouper Index
The Benthic Index compares the proportion of a reef covered by live coral and organisms
that promote reef growth versus the amount of reef covered by organisms that overgrow or Bahamian Reef Health Index
kill corals.
Coral Condition Index Individual reef sites were scored on their condition for each indicator, with grades
When a coral suffers natural stresses or human impacts, parts of the colony may die, or the
entire colony may die. This index compares the average percentage of live coral tissue on
of Poor, Impaired, Fair, and Good. The condition of an indicator on any reef may
colonies to dead coral on colonies >25 cm. reflect both environmental conditions and human impacts. For example, a reef may
Coral Disease Index be poor due to natural limiting conditions, or it may have degraded from various
Coral diseases are a major cause of coral loss on reefs. This index examines the prevalence human threats.
of various diseases on coral reefs through belt transect surveys. Sites with the lowest
percentage of disease-infected corals are the healthiest.
Coral Recruitment Index
Recruitment is measured as the number of new corals on a reef. While coral size varies
among species, for this index recruits are considered as any coral 40 cm) that can
reproduce.
Bahamian Reef Health Index (BRHI)
The scores from the other indicators are combined to calculate the BHRI by assigning the
grades of the other indicators a numberic score of 1-4 (Poor to Good), and averaging that
score. This index is only calculated for sites with at least 5 of the other 6 indicators calculated.
Reef Scores
Poor
For each geographic area surveyed, index
scores are displayed on maps using color-coded, Location Impaired
circular graphs to show the proportion of reefs N=#
Fair Map of surveyed areas and sites (2015-2019).
that received each score. The average score is
depicted by the colour of the centre of the circle. Good
2
BENTHIC INDEX
Grand
Bahama
Abaco AVERAGE CORAL >50% CORAL
N = 49
Poor
N = 20
COVER ON COVER ON
Impaired
MERMAID
Eleuthera
N = 47
SURVEYED REEFS
Fair REEF & SANDY
NP & RI
N = 27 WAS JUST
CAY REEF
11%
Good
Cat
N=7
Map of Abaco Mermaid Reef
Sandy Cay Reef
Western Abaco
Bahamas
N=7
Exuma
Cays Concep-
Andros tion
These two reefs, off-
N=9
N = 23 N=6
shore of Abaco, had
the highest amount
of live coral.
Long
N=6
Great
Exuma
N = 10
© Paul Selvaggio/SECORE Intn’l/Pittsburgh Zoo
Reefs at John Miller’s Blue Hole, off Eleuthera, had high coral cover.
Benthic Index AVERAGE
In the map above, the benthic index
SEAWEED
Finger coral (Porites porites) was one of the most
common brooding coral species in The Bahamas. compares the positive components COVER WAS
Coral Cover
of reefs that promote coral recruit-
ment and growth (e.g., the relative 46%
% Macroalgae Cover
amount of corals) to the abundance
Stressors – including the effects of seaweeds and other organisms that
of coral bleaching due to climate have a negative impact on corals.
change, disease, hurricanes, and Some of the sites with the high- IN TOTAL,
chemical and nutrient pollution – est coral cover, lowest amounts WE
have taken their toll on Bahamian of seaweeds and highest benthic
coral reefs. Across nearly all of the index scores are reefs in nation- SURVEYED
sites, reef-building corals occupied al parks, like the Exuma Cays Land 11,670 m2
less space on the reef than seaweeds and Sea Park. Cumulatively, our ben-
that rapidly take over when corals thic indices results from 1.67 million OF
die and ultimately prevent corals data points; that is, more than 11.5 Macroalgae cover (green bars) has increased on coral reefs in The
from re-establishing. km of surveyed seafloor. Bahamas compared to coral cover (yellow bars). SEAFLOOR
4
CORAL CONDITION INDEX
Grand
Abaco BLEACHING &
Bahama
N = 20
N = 55
Poor DISEASE
Eleuthera
Impaired CAN CAUSE New Providence
N = 48
TISSUE LOSS,
NP & RI Fair BUT MAY NOT
N = 27
Good KILL THE OFF NEW
>70 % COLONY PROVIDENCE,
Cat ENTIRELY CORAL
N=7
AVERAGED
OF CORALS
>44%
Westerm
OFF
Bahamas
N=7
Exuma
GRAND BAHAMA
Andros
Cays
N = 12
Concep-
tion HAD HIGH PARTIAL LIVE CORAL
N = 23 N=6
MORTALITY TISSUE
Long
N=6
Great
Exuma
N = 10
Partial Mortality of Corals
Although overall partial mortality
was fairly low for most reefs,
A coral head with significant partial mortality. with the majority of islands having
Coral Condition corals that were over 60% alive on
average, reefs off Grand Bahama,
As coral colonies are affected by New Providence and Rose Island
disease, temperature stress, predation, had higher rates of partial mortality
competition with other organisms, among coral colonies. The amount of
and other stressors, part of the colony living coral left on a colony can vary
may die. The coral condition index between species. In The Bahamas,
examines the amount of partial larger reef-building species like
mortality averaged across all coral star corals (Orbicella spp.) and brain
colonies surveyed on the reef. High corals (Pseudodiploria spp., Diploria
rates of partial mortality may indicate labrynthiformis, and Colpophyllia natans)
higher stress levels or disease (past and had the highest partial mortality
present) for the corals. rates. Brain corals (inset) and star corals (pictured) had the highest rates of partial mortality.
6
CORAL DISEASE INDEX
Grand Abaco
N = 60
Bahama
N = 20 Poor
Eleuthera
N = 47
Impaired
NP & RI Fair
N = 27
Good
Cat
N=7
Westerm
Elkhorn coral (Acropora palmata) is
Bahamas
N=7
Exuma
Cays Concep-
critically endangered globally.
Andros N = 11 tion
N=6
N = 23 Their decline was mostly due to White Band Disease; more than 3%
of elkhorn corals in The Bahamas were infected.
Long
28,787
Great
Exuma
N = 10
N=6
CORALS
SURVEYED
affects some of the more common
coral species, and Black Band Dis-
ease, which affects massive corals
and can cause significant mortality.
Overall, disease rates were low in
White band disease caused significant The Bahamas from 2015-2019 but Black band disease present on symmetrical brain coral (Pseudodiplo-
partial mortrality on this elkhorn coral. a few sites showed concerning levels ria strigosa) in The Bahamas.
of disease. Andros had the greatest
Coral Disease prevalence of disease, most of which DARK SPOT
Coral disease can be one of the was dark spot disease. Sites off New Only 1.2% of all DISEASE INFECTED
greatest sources of partial mortality Providence and Grand Bahama corals surveyed ~2% OF
and whole colony mortality. Dur- had the highest rates of more lethal LETTUCE CORALS
ing reef surveys in The Bahamas, diseases like Black Band Disease. showed signs of
eight different diseases were noted to Some sites that were surveyed over At 44% of sites, at least one dis- disease.
varying degrees. The most prevalent multiple years showed outbreaks of ease was reported. Shown here,
diseases were Dark Spot Disease, disease in one year but lower disease dark spot disease has ravaged a This was true across all surveys and
sites.
which is not highly lethal and rates in subsequent years. massive starlet coral.
8
CORAL RECRUITMENT INDEX
40%
An Abundance of Brooders
Grand Abaco In The Bahamas, over 80% of coral
Bahama N = 54 Poor recruits belonged to weedy brooding
N = 20
Impaired
OF SURVEYS species. These corals, including
HAD NO
Eleuthera
N = 48 finger coral and mustard hill coral,
NP & RI
Fair RECRUITS make smaller contributions to
N = 27 growing reefs than spawning corals,
Good which tend to be major reef builders.
Cat
N=7
>2,400 Indeed, spawning corals like star
and brain corals, provide the much-
CORAL needed structure necessary for coral
Western
recruits to settle and flourish.
Bahamas
N=7 RECRUITS
Exuma WERE
COUNTED
Cays Concep-
Andros N = 11 tion
N = 23 N=6
64% OF
ALL RECRUITS
Long
N=6
Great
BELONGED
Exuma
N = 10
TO 1 GENUS
OF BROODING
CORAL
In other words, fewer adult corals
can ultimately reduce the fertilization
success and larval production on a
A star coral recruit viewed under a microscope. given reef.
Coral Recruitment Larvae that are produced face
many challenges. Reefs overgrown
Coral recruitment – that is, the ad- by seaweeds, for example, offer less
dition of new juvenile corals to the space for larval settlement. In turn,
population – is critical for maintain- even the larvae that do settle onto
ing healthy coral reefs. As corals die overgrown reefs are at a higher risk
from bleaching, disease and other of being smothered later by seaweeds.
natural and anthropogenic causes, Adding to this problem is the low
healthy reefs are replenished by number of reef-building species
larval settlement (i.e., recruits). Re- recruiting to Bahamian coral reefs;
cruitment rates in The Bahamas are only 10% of recruits were from star, © Kevin Davidson
limited, however, due to low densi- brain, elkhorn, staghorn and massive
ties of adult corals. starlet coral species. Over five years, we surveyed 400 m2 of seafloor for coral recruits.
10
LARGE PARROTFISH INDEX
Large Parrotfish Are The Most
Grand
Bahama
Abaco
N = 49 Poor Important Grazers
Redtail (Sparisoma chrysopterum),
N = 25
Eleuthera
Impaired
N = 38
Redband (S. aurofrenatum), Yellowtail
Fair (Scarus hypselopterus) and Stoplight
NP & RI
N = 26 parrotfish (S. viride) are among the most
Good important grazers in The Bahamas.
Parrotfish were found on all reefs in
Cat surveys, but their sizes and abundance
(measured as biomass) varied among
N=7
Western
Bahamas
Stoplight parrotfish. sites. This is partly due to the natural
N=7 variability in reef structure and other
factors, but fishing is increasingly
Exuma
Cays
Concep-
tion
The figure below shows parrotfish bio- impacting parrotfish populations
Andros
N = 23
N = 12
N=6 mass by species surveyed in The Baha- - particularly for large species that
mas, between 2015-2019. contribute most to grazing.
Long
N=6
Great
Exuma
N = 10
years ago a pathogen decimated
Longspined sea urchins throughout
the region and the population has
never fully recovered. Now, large
Longspined sea urchins are important macroalgae parrotfishes are the dominant algae
grazers on coral reefs. grazers, though not all parrotfish
graze the same way.
Why Reefs Need Grazers
40%
Grazing of seaweeds is critical to Parrotfish Decline
coral reef resilience as it opens up DIADEMA Around some islands, parrotfish
space for coral larvae to settle onto DENSITIES ARE populations have decreased over DECREASE
clean substrate, as well as prevents the past five years. The mean IN MEAN
new recruits from being smothered
by seaweeds. The most important
10-100x biomass values of key grazing PARROTFISH
parrotfish around New Providence
grazer on Caribbean reefs was once LOWER THAN & Rose Island, for example, has BIOMASS AROUND
the Longspined sea urchin, Diadema BEFORE THE DIE- decreased from 1,715 g/100 m2 in NEW PROVIDENCE
antillarum. Unfortunately, over 35 OFF 2011 to only 685 grams/m2 in 2019. FROM 2011-2019
12
GROUPER INDEX
NASSAU
Grand
Bahama
Abaco
N = 49 Poor GROUPERS
N = 20
TYPICALLY
Impaired
REPRODUCE
Eleuthera
N = 47
NP & RI
Fair WHEN THEY
N = 26
Good ARE
Cat
N=7
>54 CM
Western
Bahamas
N=7 Bahamian Nassau groupers spawn
Exuma
Cays Concep-
only once per year.
Andros N = 12 tion
N = 23 N=6
Long
N=6
Great
Exuma
N = 10
© Shane Gross The Nassau Grouper is
Critically Endangered
A spawning aggregation of Nassau grouper. The Nassau grouper has been fished
out from much of the Caribbean The Black grouper is a key predator on coral reefs.
Reefs Depend on Groupers and is considered a critically endan-
© Shane Gross
Groupers are of economic and gered species; in fact, they are more
ecological importance to coral reefs. endangered than Giant pandas and
As predators, they play a key ecological African elephants. The Bahamas NASSAU NASSAU
role by controlling populations of other remains one of the few places where GROUPER GROUPER
fish and invertebrates that they feed populations of large groupers are FISHERIES WILL
on, including those that are predators still viable. Still, even here, we see
on corals. They are also among the reduced populations in some areas ARE MIGRATE
most valuable fishery species in The where fishing pressure is high. The WORTH >100
Bahamas. Large grouper species healthiest populations are in marine >$32 MILES
have become rare throughout the protected areas (MPAs), where fish-
Caribbean. ing is restricted. MILLION TO SPAWN
14
BAHAMIAN REEF HEALTH INDEX
Abaco Conception Island
Coral Coral Large Coral Coral Large
Benthic Conditon Disease Recruitment Parrotfish Grouper Benthic Conditon Disease Recruitment Parrotfish Grouper
Abaco
Grand
Bahama
N = 53
Poor
N = 20
Impaired
Eleuthera
N = 39 While the majority of reefs had Conception Island stood out
Fair below average BRHI scores, with some of the healthiest
NP & RI
N = 25 Abaco also had two reefs with reefs surveyed in The
Good the highest amount of live Bahamas, likely due to both its
coral cover in the country – remote location and its status as
Cat
Sandy Cay Reef and Mermaid a national park. Nevertheless,
Western
N=7
Reef. At restoration sites, critically there was evidence of reduced
Bahamas
N=7
endangered staghorn and elkhorn populations of elkhorn coral,
populations are increasing. staghorn coral and other critically
Continued monitoring of Abaco’s endangered corals in several
Exuma
Cays
Concep-
tion
reefs will determine long-term locations, likely as a result of
Andros
N = 23
N = 11
N=6
impacts of Hurricane Dorian. past bleaching or disease events.
Restoration of these populations
Andros may contribute to their recovery.
Coral Coral Large
Cat Island
Benthic Conditon Disease Recruitment Parrotfish Grouper
Long Coral Coral Large
N=6 Benthic Conditon Disease Recruitment Parrotfish Grouper
Great
Exuma Over 75% of reefs surveyed off
N = 10
Andros had above-average BRHI
scores, but had a higher than Sites off Cat Island had above
average prevalence of disease. average scores for reef condition,
A mass bleaching event in 2015 but higher than average rates of
posed threats to coral reef health. disease, and low coral cover. It’s
High coral recruitment may be possible these reefs exhibited lower
the result of both higher than levels of disease and bleaching in the
Bahamian Reef Health Index average coral cover and local past, and rates are increasing now,
retention of larvae. although more surveys are needed.
To assess the overall health of reefs, sand dredging has occurred for
the Bahamian Reef Health Index decades. Despite having some reefs
(BRHI) averages the scores of the with the highest live coral cover in
other reef health indicators for each The Bahamas, Abaco’s reefs suffered
site. The only areas where BRHI with the lowest coral recruitment
scores averaged more than 3.0 were index, low coral cover on average,
Conception Island (3.19) and the and fewer large groupers than other
Exuma Cays Land and Sea Park sites. Reefs off New Providence
(3.14), the former being a remote and Grand Bahama were scored
area and receiving national park as IMPAIRED overall, primarily
protection (although enforcement due to lower than average grouper
is limited), and the latter, a well- and parrotfish index scores, as well
protected no-take national park with as poor reef condition scores for
relatively low levels of development. New Providence/Rose Island, and
The location with the lowest scores poor recruitment scores for Grand
was Western Bahamas (2.19), where Bahama. Only one site received a score of Good for all indices – Friday’s Reef in the ECLSP.
16BAHAMIAN REEF HEALTH INDEX
Western Bahamas Grand Bahama New Providence & Rose
Coral
Benthic Conditon
Coral Large Coral Coral Large Island
Disease Recruitment Parrotfish Grouper Benthic Conditon Disease Recruitment Parrotfish Grouper
Coral Coral Large
Benthic Conditon Disease Recruitment Parrotfish Grouper
Reefs around Western Bahamas – Sixty percent of Grand Bahama’s
including Ocean Cay and Bimini reefs received BRHI scores of While reefs off New Providence
- received the lowest overall BRHI POOR or IMPAIRED, with the and Rose Island were generally
score. This is likely because the vast majoritiy having below aver- below average for several indices,
area around Ocean Cay was com- age benthic index scores and higher including the Parrotfish Index
mercially dredged for decades. Exuma Cays than average disease scores during (84% of sites) and Benthic Index
Despite having better than aver- Coral Coral Large surveys in 2018 and 2019. Further (>75% of sites), there were some
age coral coverage, benthic scores Benthic Conditon Disease Recruitment Parrotfish Grouper damage from Hurricane Dorian in differences in aspects of reefs
were low due to high amounts late 2019, as well as the outbreak between those off Rose Island
of cyanobacteria and turf alga- All but one of the sites assessed of SCTLD in late 2019 and early in the east and those off western
sediment mats that inhibit coral in the Exuma Cays were in the 2020, pose significant new threats New Providence. Nari Nari Reef
growth. Plans for protection and Exuma Cays Land and Sea Park to Grand Bahama’s reefs. off western New Providence also
restoration in this area can dra- (ECLSP), the country’s oldest and Long Island had the greatest loss of living coral
matically improve reef condition. most effectively managed MPA. As Coral Coral Large
reported over the past decade,
Eleuthera a result it had some of the healthiest
Benthic Conditon Disease Recruitment Parrotfish Grouper likely due to petroleum leaking
reefs, with the highest live coral into the water from nearby Clifton
Coral
Benthic Conditon
Coral Large
Disease Recruitment Parrotfish Grouper
coverage and grouper biomass, Like Cat Island, Long Island has Pier.
as well as the lowest macroaglae a minimal number of reefs sur-
Eleuthera had some of the largest abundance of any area. One reef in veyed, so additional assessments are
the ECLSP was the only one in The needed to paint a clear picture of
reef area surveyed, which varied
from reefs exposed to the open Bahamas to receive GOOD scores coral reef health. Reef condition off Only 3%
ocean on the eastern side of the is- for all indices. Long Island was above average, but OF ALL SITES
land, and those more sheltered on Great Exuma exhibited below average scores of SURVEYED WERE
the Exuma Sound side of the is- coral cover and high levels of dis-
Coral Coral Large
ease; this suggests, despite low levels RATED “POOR”
land. As such, reefs varied consid- Benthic Conditon Disease Recruitment Parrotfish Grouper
erably in ecological factors. While of bleaching and disease in the past, OVERALL
Eleuthera had one site that ranked these rates might be increasing.
Reefs surveyed off Great Exuma
among the top sites in coral cover were all within the Moriah
and health, 90% of sites had be- Harbour Cay National Park. All Around Conception Island, all sites rated “FAIR” or better.
low average benthic index rank- sites exhibited above-average
ings, primarily due to low coral coral condition and coral cover, as
and high macroalgae cover. well as below average macroalgae.
The reduction in macroalgae may
be due to above average parrotfish
populations at most of the sites.
60% OF SITES
RATED IN
“GOOD”
A brittle star settles on a spawning star coral. HEALTH
WERE IN MPAs © Shane Gross
18THREATS Hurricanes
and was one of the slowest moving Because many affected reefs were
major hurricanes, as it moved across already considered IMPAIRED
Grand Bahama and eventually exited before the storm, their ability to
The Bahamas over the northern Aba- recover may be compromised and may
cos. The storm caused devastation to require restoration efforts.
many reefs, including coral damage,
bleaching, the influx of debris from
land ranging from whole trees to pieces
of houses and cars, and burial in sedi-
ment from inshore areas. While some
reefs, like Sandy Cay Reef in the Peli-
can Cays Land and Sea Park, saw min-
imal impacts from the storm, Mermaid
Reef, which had the highest percent-
age of live coral of any reef surveyed in
The Bahamas, suffered severe damage;
about 30% of Mermaid Reef’s corals
were dislodged and moved, leading to a
reduction of coral cover by 40%.
This map traces the pattern of damaged reefs that we surveyed after Hurricane Dorian. The hurricane
symbols depict Hurricane Dorian’s path at 6-hour time intervals after it struck Abaco on Sepember 1.
Hurricanes in The Bahamas
Around the world, coral reefs are the ability of reefs to recover from
often found in the areas most affected severe damage.
by tropical cyclones. No place is Hurricane Dorian
this more evident than in The
Bahamas. Over the past century, In September 2019, Hurricane
The Bahamas has experienced at Dorian became the strongest
least one hurricane or tropical storm hurricane to make landfall in the
event every 2 years, with some Atlantic. It first hit Central Abaco Hurricane Dorian’s effects were severe, both on land and underwater.
islands experiencing hurricanes © Will Greene
more frequently than others. While
hurricanes can have devastating
impacts to reefs, healthy reefs are 1/3 CASUARINA TREES
resilient and can recover from most OF SITES OFF THAT WERE SWEPT
storms. Unfortunately, reefs that are GRAND BAHAMA & ONTO REEFS
in decline from other threats may ABACO HAD MORE
not be resilient to hurricanes and the CAUSED THE
frequency and intensity of storms over BROKEN CORAL MOST DAMAGE
the past couple of decades may limit © Will Greene AFTER DORIAN
20THREATS Coral Bleaching
SOME CORALS
MAY HAVE
GENETIC
ADAPTATIONS TO
TEMPERATURE
STRESS
Mermaid
Reef
Abaco
For example, corals
Percent of surveyed corals that bleached from 2015-2019. on Mermaid Reef off
Abaco.
CORALS CAN
RECOVER FROM
MILD BLEACHING
This map compares the 2015 bleaching event near Andros (left) and South Abaco (right). Off Andros,
70-100% of all corals surveyed had bleached; this range was 37-70% of corals around S. Abaco.
Coral Bleaching
Reef-building corals rely on are more susceptible to disease and
nutrients from a symbiotic other stressors that can kill them
relationship with microscopic algae, later. Mass bleaching events were But they may be more
called zooxanthellae, that live in first noticed in the 1980s and have vulnerable to disease, and
their tissue. When environmental increased in frequency and intensity less likely to reproduce.
conditions become too stressful, recently. In The Bahamas, 2015 was
this symbiosis breaks down and a particularly bad bleaching year.
corals expel their zooxanthellae; as Shortly after summertime temperature AFTER
a result, the corals appear white, a highs, nearly HURRICANE
phenomenon known as bleaching. 70% of corals DORIAN, >25 %
This often happens in the summer, surveyed off OF CORALS HAD
when water temperatures are Andros and BLEACHED ON
warmer than usual. If conditions Abaco were SOME REEFS.
get too warm (e.g., if waters remain bleached, with
≥0.5 °C above normal conditions 100% of corals This was likely caused
A bleached star coral colony (Orbicella faveolata) from Sandy Cay by rapid temperature
for an extended period of time), the bleached at A bleached spiny flower coral. Reef in 2015 (top). Fortunately, four years later (i.e., 2019; bot-
corals can die. Corals that recover some sites. changes or prolonged
tom) 100% of that same coral head had recovered from bleaching. water turbidity.
22THREATS Coastal Development
New Providence have experienced
significant changes. For example, Grand REEFSTHREATS Stony Coral Tissue Loss Disease
SCTLD Spread
Surveys of infection and mortality FOR MORE
rates suggest that SCTLD may have INFO ON SCTLD,
first affected reefs around the port VISIT US AT
and spread from there. How and HTTP://WWW.
when the disease reached Grand PERRYINSTITUTE.
Bahama is unknown. However, ORG/SCTLD
transport via shipping is suspected
and the rapid spread of the disease
may be the result of natural ocean
currents, the effects of Hurricane IN MARCH 2020,
Dorian, and potentially human 80% OF
activities such as boating, fishing, SYMMETRICAL BRAIN
and diving. Preventing the spread of CORALS OFF GRAND
this devastating disease is critical to BAHAMA WERE
limit coral loss in The Bahamas, and DEAD / INFECTED
prevent broader impacts to coral reef FROM SCTLD
ecosystems as a whole.
Spread of SCTLD along the south coast of Grand Bahama is rapidly infecting and killing reef building
corals, like symmetrical brain coral (Pseudodiploria strigosa; pictured on Page 27).
observed on any of Grand Bahama’s
reefs during AGRRA surveys that
month off West Grand Bahama and
later, in October 2019, in Peterson
Cay National Park, Lucayan National
Park and East Grand Bahama. By
March 2020, all of this area had been
Grand Bahama’s port, where SCTLD may impacted by SCTLD to some extent,
have been introduced in The Bahamas. with 18 species of corals observed
to be infected and up to 95% of
some species either recently killed or
Stony Coral Tissue Loss infected by the disease. SCTLD has
Disease in The Bahamas also been confirmed off Nassau.
In 2020, the first outbreak of Stony
Coral Tissue Loss Disease (SCTLD)
was confirmed in The Bahamas near
Grand Bahama. Although anecdotal
1/2
REEF-BUILDING
reports suggest the disease may have CORAL SPECIES
spread to reefs off Freeport as early as ARE AT RISK OF
July 2019, no cases of SCTLD were SCTLD Major reef-building corals, like brain corals (pictured) and star corals, are the most affected species.
26THREATS Unregulated Fishing
Fisheries Management in The
Bahamas PARROTFISH
While the major commercial fisheries CAN REMOVE
of The Bahamas, including lobster, UP TO
conch and grouper, have regulations
such as size limits or closed seasons 2 GRAMS/M2
to promote sustainable fisheries, most OF CARBON
reef fish species have no regulations ANNUALLY
based on their biology to protect them.
An example of this is the emerging
parrotfish fishery. Parrotfish are
not considered a traditional fishery In the Exuma Cays Land and Sea
species in The Bahamas, but capture Park, parrotfish grazing intensity was
of parrotfish has become widespread Increased grazing in the Exuma Cays Land and Sea
and poses a significant threat to coral Park (ECLSP) led to a 2x increase in recruitment. 2x higher than outside the park.
reefs. Indeed, parrotfish are one of the
few groups of fish that can build reef 2015-2019
resilience and help coral populations
recover by controlling seaweed
growth.
Parrotfish Decline
Over the past decade we have
studied parrotfish populations and
aspects of the fishery around The
Bahamas. Surveys of the fishery
have indicated that parrotfish are
harvested throughout The Bahamas, 2011-2019
but are mostly targeted by fishers
from New Providence. In-water
surveys of parrotfish comparing
populations over the past decade
show a decrease in parrotfish
populations at 84% of sites Blue, rainbow and stoplight parrotfish are the most commonly harvested species.
around New Providence and
Rose Island and that parrotfish
biomass decreased by an average
of 64% over the past decade. These
numbers are alarming, as they 64% 28%
indicate a reduction in the resilience OF FISHERMEN OF FISHERMEN
of coral reefs at the same time
REPORTED CATCH
that reefs face increasing threats The maps above show the percent change in PARROTFISH
from climate change, hurricanes, parrotfish biomass on coral reefs around New HARVESTING EVERY TIME
pollution and changes to the coastal Providence and Rose Island, from 2015-2019 and PARROTFISH
environment. 2011-2019, respectively. THEY GO OUT
28SUCCESSES Coral Restoration
Coral Nurseries At Midway Reef (off
Though microfragmentation and S. Abaco), staghorn
larval propagation techniques and elkhorn coral
are largely still in development, restoration began in
2011. From 2015-
coral nurseries have been used in 2019, these two
The Bahamas for over a decade. species increased by
Currently, there are ~25 coral 40% and 50% on
nursery sites, growing over 6,000 this reef, respectively.
coral fragments. The success of
these efforts is just beginning to
be realized. For example, the only
documented increases in the amount
of staghorn and elkhorn coral in our
surveys are from sites off southern
Abaco, where restoration efforts
have been going on for ten years.
Coral nursery locations within the Reef Rescue Network. The size of the symbol represents the number of
coral fragments growing at each nursery.
Reef Restoration in The endangered elkhorn and staghorn
Bahamas coral, small fragments from
Several coral species are considered naturally occurring colonies are
endangered or critically endangered grown in nurseries at increased
in The Bahamas. The declines we rates and used to re-populate reefs.
observed may have reduced coral (2) For slower-growing mounding
populations below critical thresholds corals, a new technique called
for successful reproduction; this is microfragmantation was developed
because successful fertilization of to increase live coral cover, though
eggs during coral spawning depends this is a resource-intensive process. © Shane Gross
on having genetically unique (3) Finally, we can increase the
colonies in close proximity to each number and genetic diversity of
other. As such, many coral reefs may corals by collecting gametes whenSUCCESSES Exuma Cays Land and Sea Park
Bahamas. Largely based on the success
of the ECLSP, the government of The
Bahamas is committed to protecting
20% of its nearshore waters by the end
of 2020.
COMPARED TO THE REST
OF THE BAHAMAS, IN THE
ECLSP:
NASSAU GROUPER
MPAs preserve ecosystem processes that promote DENSITIES WERE
healthy reefs. 80% HIGHER,
The ECLSP & BIOMASS PER
HECTARE WAS
The Exuma Cays Land and Sea Park 150% GREATER
is the oldest and best-enforced MPA
in The Bahamas. Protected since
1959, and being entirely no-take since
1986, many studies have shown that BLACK GROUPER
populations of fish, conch, crawfish DENSITIES WERE
and corals are healthier in the ECLSP 40% HIGHER,
than other parts of The Bahamas. & BIOMASS PER
For example, coral recruitment HECTARE WAS
was 50% greater on average in the 450% GREATER
ECLSP than other sites in The
More than 11% of nearshore waters in The Bahamas are protected within MPAs, however the country has
committed to nearly doubling its MPA network to 20% by the end of 2020.
Marine Protected Areas
Marine Protected Areas, MPAs, are travel into fished areas. Further, as
parts of the sea that receive special more and more fish reach spawning
protection from human threats. size within MPAs, they export
Typically, they restrict or limit larvae to surrounding fished areas.
certain activities to promote more
natural conditions. For example,
MPAs may restrict fishing activities
to allow populations to recover,
or prohibit anchoring to protect CORAL COVER
sensitive habitats. MPAs don’t WAS 76% GREATER
just protect resources within their ON AVERAGE IN
boundaries. As healthy populations THE ECLSP THAN © Shane Gross
of fish and other species develop in OTHER SITES IN
MPAs, some individuals may THE BAHAMAS Conch populationsa are healthier in the ECLSP than in nearby areas.
32BALANCING PROTECTION & DEVELOPMENT Eleuthera
is permitted or where reefs
are protected, ecological
evaluations must also be used
to identify areas that are
particularly sensitive to coastal
development and to prioritize
areas for protection based on
ecological integrity. Protection
from various threats and active
restoration can improve the
condition of most coral reefs,
however identifying priority
areas for protection is key.
ELEUTHERA’S
PROPOSED MPAs The graph above shows biomass (g/100 m2) of several key commercial
AVERAGED 6.36% fish species off Eleuthera. Groupers (yellow), snapper (purple) and
LIVE CORAL grunts (blue) are displayed.
© Shane Gross
This map shows the average percent of live coral cover on reefs off Eleuthera. Some of the noteworthy sites
are currently in proposed MPAs while others are likely to remain unprotected.
A Balancing Act Eleuthera
Many Islands in The Bahamas are Nowhere is the difficulty of establishing
currently faced with balancing the a balance between coastal development
economic opportunities provided and protection more evident at
by coastal development and the present than Eleuthera, where there
expansion of tourism with the is increasing coastal development in
conservation of marine resources to support for cruise ship-based tourism,
preserve marine ecosystems and the resorts, marinas, and second homes. Off Eleuthera, the site with the highest coral cover (34%) and the site with the most critically endangered Staghorn
coral (9.5%) were not included in proposed MPAs. However, the site with the most critically
valuable services they provide. Our At the same time, there are nine endangered Elkhorn coral (21%, pictured) was inlcuded.
data show that coral reefs within new MPAs
well-managed MPAs are among proposed
the healthiest in The Bahamas, around the REEFS OFF LIGHTHOUSE POINT, WHERE BOTH PROTECTION
and those closest to population island. While AND DEVELOPMENT IS PROPOSED, HAD:
concentrations and industrial centers various social
often are impaired or in poorer and economic ONLY LESS THAN 30%
health. Nevertheless, there are some factors must 5.4% 1/2 BELOW
examples where coral reefs remain play a role in LIVE CORAL THE NATIONAL ELEUTHERA’S
healthy near population centers or determining AVERAGE (11.7%) AVERAGE (7.7%)
have improved through sustained where coastal COVER OF LIVE CORAL OF LIVE CORAL
Lighthouse Point off Eleuthera.
restoration and monitoring efforts. development
34HOW CAN I HELP?
AS A COUNTRY, WE CAN: AS A COMMUNITY
EAT 1. Support MPAs. Create MPAs with active WE CAN:
SUSTAINABLE management and enforcement, such as Marine Parks
SEAFOOD & AVOID and Fishery Reserves. The Bahamian government
KEY SPECIES has committed to protecting 20% of its marine
FOR REEF environment in MPAs this year! But these areas will
HEALTH, LIKE only be successful if they have management plans
that include protection from key threats, and if people
PARROTFISH comply with those regulations.
Clean up any trash, oil
2. Regulate and manage fisheries. Less than 10 or waste you see outside.
fishery species in The Bahamas are managed through
minimum sizes, closed seasons and other harvest
restrictions. Many species like snappers, grunts,
hogfish and parrotfish are unregulated. These species RESTORE
should be assessed and managed to ensure their NATURE
© Kevin Davidson sustainability. There needs to be better compliance
Try lionfish, an with existing regulations, including improved
invasive fish species, How can we protect coral reefs? enforcement, eliminating illegal foreign fishing, and
instead! ensuring all fishers understand fishing regulations.
Coral reefs face a number of natural and human-caused
DISPOSE OF threats, which are often increased by human impacts. 3. Implement sustainable coastal development. REPLANT
YOUR WASTE Although reef health has undoubtedly declined, we Because The Bahamas’ economy is so dependent on MANGROVES
can take many steps, as individuals and as a country, tourism within the coastal zone, coastal development OR REPLACE
PROPERLY to: 1) prevent further damage to coral reefs, 2) is inevitable. Identifying sensitive areas and using this INVASIVE
improve their resilience to promote natural information for planning is critical to preserve the CASUARINA
recovery, and 3) actively restore key species. natural resources upon which tourism depends. To
The actions described here will not only support the prevent further damage to reefs, coastal development TREES WITH
natural beauty, ecological function, and biodiversity operations must: 1) include mitigation measures NATIVE PLANTS
of reefs, but will help ensure they continue to provide for impacts to sensitive habitats like coral reefs, 2)
Bahamian people with invaluable ecosystem services. develop adequate waste disposal systems, and 3) SUPPORT LOCAL
Chemicals that go remove invasives, like Australian pines (also known as
down the drain end ON THE WATER, WE CAN: Casuarina), and replace them with native species. BUSINESSES
up in the ocean
and damage coral ANCHOR KEEP MAINTAIN
reefs. ON SAND, CHEMICALS, OUR
AWAY LIKE BOATS
CONSERVE TO AVOID
ENERGY! FROM BLEACH,
CLIMATE CHANGE CORAL AWAY FROM FUEL &
ASK
IS A BIG THREAT REEFS WATER OIL LEAKS RESTAURANTS
TO CORAL REEFS NOT TO SERVE
PROTECTED,
Turn off your lights, UNDERSIZED OR
take quick showers,
and unplug your OUT OF SEASON
© Kevin Davidson
unused electronics. REEF SPECIES
36CONTRIBUTORS
Citation
Dahlgren C., K. Sherman, L. Haines, L. Knowles, K. Callwood. 2020. Bahamas
Coral Reef Report Card Volume 2: 2015-2020.
AGRRA Data Collection
Shelby Allen (Disney), Kemit Amon Lewis (TNC), Lakeshia, Anderson (BNT), Fred Arnett
(TNC), Vanessa Benjamin (BNT/BahaMar), Tamanji Bethel (Design Elements), Candice Brittain
(CEIS), Dan Brumbaugh (UC Santa Cruz), Janeen, Bullard (Design Elements) Shelley Cant-
Woodside (BNT), Hayley-Jo Carr (PIMS), Shaun Christean (Middlebury College), Craig Dahlgen
(PIMS), Giselle Dean (BNT), Brooke Gintert (U. Miami), Will Greene (Middlebury College), Eric
Grunthaner (Disney), Lily Haines (PIMS/CEI), Drew Hitchens (CEIS), Lashanti Jupp (BNT), Tanya
Kamerman (Disney/Nova Southeastern University), Luke Kikukawa (Middlebury College), Kristin
Kimble (Middlebury College), Lindy Knowles (BNT), Jillian Lessing (Middlebury College), Agnessa
Lundy (BNT), Christy MacDonald (Disney), Sheldon Mackey (Design Elements), Scott Martin
(Disney), Helena Milazzo (Middlebury College), Rochelle Newbold (BEST Commission), Valeria
Pizarro (CEIS), Elise Quinton (Gap Force), Mallory Raphael (BREEF), Krista Sherman (PIMS),
Nikita Shiel-Rolle (YME), Andy Stamper (Disney), Kristine Stump (Shedd Aquarium/CEIS), Tonika
Sweeting (Atlantis), Collin Tennant (Disney), George Valentine (Middlebury College), Kathryn Van
Artsdalen (Middlebury College), Alannah Vellacott (PIMS), Sandy Voegeli (San Salvador Living
Jewels), Brad Weiler (CEIS), Liv Williamson (RSMAS), Anna Willig (Middlebury College), Anna
Zuke (CEIS)
Graphic Design: Lily Haines and Dawn Witherington.
Photos: © Perry Institute for Marine Science, unless noted.You can also read
