Giglio-2015-Recreational-Diver-Behavior-and-Contacts

Environmental Management
DOI 10.1007/s00267-015-0628-4
Recreational Diver Behavior and Contacts with Benthic
Organisms in the Abrolhos National Marine Park, Brazil
Vinicius J. Giglio1,2 • Osmar J. Luiz3 • Alexandre Schiavetti4
Received: 23 April 2015 / Accepted: 17 November 2015
! Springer Science+Business Media New York 2015
Abstract In the last two decades, coral reefs have
become popular among recreational divers, especially
inside marine protected areas. However, the impact caused
by divers on benthic organisms may be contributing to the
degradation of coral reefs. We analyzed the behavior of
142 scuba divers in the Abrolhos National Marine Park,
Brazil. We tested the effect of diver profile, reef type, use
of additional equipment, timing, and group size on diver
behavior and their contacts with benthic organisms. Eightyeight percent of divers contacted benthic organism at least
once, with an average of eight touches and one damage per
dive. No significant differences in contacts were verified
among gender, group size, or experience level. Artificial
reef received a higher rate of contact than pinnacle and
fringe reefs. Specialist photographers and sidemount users
had the highest rates, while non-users of additional
equipment and mini camera users had the lowest contact
rates. The majority of contacts were incidental and the
highest rates occurred in the beginning of a dive. Our
findings highlight the need of management actions, such as
& Vinicius J. Giglio
[email protected]
1
Programa de Pós-graduação em Ecologia e Conservação da
Biodiversidade, Universidade Estadual de Santa Cruz, Ilhéus,
Brazil
2
Present Address: Programa de Pós-graduação em Ecologia,
Universidade Federal do Rio de Janeiro, Rio De Janeiro,
Brazil
3
Department of Biological Sciences, Macquarie University,
Sydney 2109, NSW, Australia
4
Departamento de Ciências Agrárias e Ambientais,
Universidade Estadual de Santa Cruz, Ilhéus, Brazil
the provision of pre-dive briefing including ecological
aspects of corals and beginning dives over sand bottoms or
places with low coral abundance. Gathering data on diver
behavior provides managers with information that can be
used for tourism management.
Keywords Dive tourism ! Marine protected area !
Management ! Scuba divers ! South Atlantic ! Tourism
management
Introduction
Coral reefs are important habitats along tropical coastlines,
providing humans with economic resources and services
through cultural values, fishing, coastal protection, and
tourism (Moberg and Folk 1999). This ecosystem is also a
popular destination for scuba diving, one of the world’s
fastest growing recreational sports (Van Treeck and
Schuhmacher 1998; Hasler and Ott 2008). Scuba diving is
considered to be a low-impact activity and provides an
economic alternative to fishing through a non-extractive
use of marine wildlife (Davis and Tisdell 1995; Tapsuwan
and Asafu-Adjaye 2008). However, coral reefs are globally
threatened by a wide range of anthropogenic activities,
such as fishing, pollution, and unplanned tourism (Bellwood et al. 2004). These activities act in synergy with the
high vulnerability of corals to climate change (Hughes
et al. 2003), rendering the sustainable use of coral reefs a
complex task. The recent growth of diving tourism has
raised concern among managers and scientists regarding its
impacts. For instance, in Eilat reefs, Israel, visitation rates
account for 250,000–300,000 divers and 400,000 instances
of coral damage per year (Zakai and Chadwick-Furman
2002).
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Environmental Management
No-take Marine Protected Areas (MPAs) have recently
become widely recognized as a key tool for biodiversity
conservation and fisheries management, especially in coral
reefs (Jones 2001). The reduction in fishing pressure
through the closure of selected areas has led to the reappearance of rare or absent species and substantially
increases the biomass of apex predators (Anderson et al.
2014; Edgar et al. 2014). There are also positive effects for
coral reefs, such as increase of coral cover and structural
complexity (Selig and Bruno 2010). Increases in fish
abundance and coral cover make MPAs highly attractive to
the diving industry. Today, scuba diving is one of the most
important commercial uses of MPAs (Green and Donnelly
2003). However, in some cases, large numbers of dives
have resulted in decline in the health of coral reefs (Davis
and Tisdell 1995; Uyarra and Côté 2007).
Divers can damage corals through direct (physical
contact) or indirect contact (via sediment deposition) with
their hands, body, scuba gear, and fin kicks (Harriot et al.
1997; Rouphael and Inglis 1997). Due to the delicate
structure of corals, contacts often result in breakage,
abrasion, or tissue removal (Hawkins et al. 1999). Damaged corals are more susceptible to predation, competition
interference, and disease, which can result in death of the
colony (Guzner et al. 2010). Algal colonization on corals
may soon follow tissue damage. Algae compete for space
with corals and can act as a sediment trap, hindering coral
recovery (Hall 2001). Fin kicks on the bottom disturb and
re-suspend sediment that can settle nearby, including on
corals (Zakai and Chadwick-Furman 2002). When sediment covers the coral surface in excess, coral recruitment,
feeding, and photosynthesis are inhibited (Hasler and Ott
2008).
Since the 1990s, studies have investigated the dynamics
of diver and benthic organisms contacts (e.g., Hawkins and
Roberts 1992; Hawkins et al. 1999; Plathong et al. 2000;
Barker and Roberts 2004; Lucrezi et al. 2013). The characteristics that affected the rates of diver contacts on reefs
were related to diver’s profile, such as their experience (Di
Franco et al. 2009), gender (Rouphael and Inglis 2001),
dive purpose (Uyarra and Côté 2007), use of additional
equipment (e.g., cameras, gloves and lanterns; Rouphael
and Inglis 2001; Uyarra and Côté 2007; Poonian et al.
2010), and biophysical characteristics of dive site (e.g., reef
type and coral cover; Rouphael and Inglis 1997; Hawkins
et al. 1999). Sites with complex topographies can make it
difficult for divers avoid touching corals on vertical
structures (Rouphael and Inglis 1995). However, the correlation between coral damage and reef topography is
unclear (Zakai and Chadwick-Furman 2002). The lack of
awareness by divers of their own impacts on reefs has
contributed to a substantial amount of human-induced
damage on corals (Rouphael and Inglis 1995). In Thailand,
123
Dearden et al. (2007) verified that only 30 % of divers were
aware of negative environmental impacts created by their
dive group. In summary, there is not a general pattern of
relationships among diver behavior and rate of contacts on
reefs. Patterns of diver impacts are generally site-specific,
so further studies and dive site management should be
narrowly focused to be of maximum practical use.
Understanding diver behavior is important to subsidize the
carrying capacity and verify management strategies to
reduce impacts of recreational diving.
Previous studies have demonstrated that underwater
photographers inflicted high rates of damages to corals
(Rouphael and Inglis 2001; Chung et al. 2013). Photographers stay close to the substrate and may accidentally come
into direct contact with the reef or deliberately hold on the
corals to stabilize themselves to photograph a subject.
Rouphael and Inglis (2001) evaluate the behavior of specialist and non-specialist photographers and verified that
specialists caused higher rates of damage than non-specialists. However, since then, several models of easy-to-use
underwater cameras have recently been developed and the
effect on diver behavior of these snapshot cameras has not
yet been evaluated, as well as the use of new diving gear
configurations.
To mitigate diving impacts, studies have proposed the
establishment of carrying capacity approaches (Davis and
Tisdell 1995; Rı́os-Jara et al. 2013) and the use of predive educational briefings (Medio et al. 1997; Camp and
Fraser 2012). However, diver’s behavior and compliance
to the norms vary according to diver’s profile, objectives,
and characteristics of the dive site (Smith et al. 2010;
Giglio et al. 2015). For example, the use of pre-dive
briefings reduced 60 % of diver’s contacts with corals in
Egypt (Medio et al. 1997). On the other hand, in Santa
Lucia (Lesser Antilles, Caribbean), group leader intervention was the only effective method to reduce coral
damage (Barker and Roberts 2004). The use of artificial
reefs has been proposed as a strategy to reduce impacts on
natural reefs (Polak and Shashar 2012). Shipwrecks are
often used as a diving attraction, mainly due to their
esthetic appeal (Leeworthy et al. 2006). These structures
generate revenue through diving tourism and consequently
assist in local economic development (Pendleton 2005).
Historical shipwrecks represent an important cultural
heritage and are fragile, non-renewable resources, generally protected by law (Jewell 2004). However, the impact
caused by scuba divers on its benthic fauna incrusted
remains little understood. To implement and adequate
artificial reef program, it is essential to understand diver
impacts on historical structures and its fauna, and
assessing potential impacts of artificial structures on
marine biota, such as phase shifts of benthic assemblages
(Work et al. 2008).
Environmental Management
Despite the increasing interest in coral reef conservation, assessments of recreational dive damage have not yet
been carried out on benthic organisms (e.g., scleractinian
corals, fire corals, gorgonians, and sponges), and how
divers contributes to these impacts in Brazil. In this study,
we examined scuba diver behavior through direct observations in order to identify factors that may influence their
contacts with benthic organisms in the Abrolhos National
Marine Park (ANMP), a no-take MPA in eastern Brazil.
The ANMP is part of the largest and most biodiverse coral
reef complex in the South Atlantic (Leão et al. 2003) and is
considered one of the best diving destinations in Brazil. We
verified the rate of scuba divers’ contacts with benthic
organisms according to (1) divers’ profile (gender, age, and
experience); (2) reef type; (3) use of additional equipment
(e.g., camera and sidemount); (4) divers’ group size; and
(5) dive time. We also estimated the rate of contacts under
current visitation rates and suggested management measures to reduce coral reef damage in the ANMP.
Materials and Methods
Study Area
Comprising an area of 965.67 km2, the ANMP was created
in 1983 aiming to conserve biodiversity and to promote
sustainable tourism, educational, and research activities.
Eighteen coral species occur in ANMP and of these, eight
are endemic to South Atlantic, and one endemic to eastern
Brazil (Leão and Kikuchi 2001). In the 1990s, unofficial
estimates suggested that ANMP received approximately
10,000 visitors per year. However, annual visitation has
decreased by one-third when compared with 2002 estimate
(Alvarenga and Fleck 2011). At the time of writing, ANMP
received an average of 3500 visitors per year, peaking
during the austral summer, due to good dive conditions and
higher underwater visibility.
Fishing or collection of organisms is forbidden within
the ANMP, as well as the use of gloves and knives. The
first dive in each tourism operation is restricted to shallow
reefs (\10 m depth), focusing equipment and buoyancy
control adjustments. Group leaders take a maximum of
eight divers in a group.
Diver Behavior
The underwater behavior of scuba divers was assessed
through direct observation. Observers sampled two divers
at a time. Three distinct dive operators were sampled over
7 weeks during the austral summers (January to March) of
2012 and 2013. We sampled all divers on 20 liveaboards
trips that performed generally eight dives along 3 days.
Divers were unaware that they were being observed to
avoid influencing their behavior. Observers blended in the
dive party and remained inconspicuously behind their
subjects, within visual contact (usually 2–4 m away). Each
sample period began when divers approached the reef and
ended when they return to the boat, moving away from the
reef. We quantified four types of dive contacts, according
to the part of the diver body or gear with which they touched, damaged, or raising sediment onto benthic organisms: fin, knee, hand, and scuba gear (e.g., spare regulator
and air tank). Diver contacts were recorded on a PVC slate
and classified as touch, damage (when physical damage
occurs), or raising sediment onto corals. Timing was
grouped into categories (e.g., 0–10, 11–20, 21–30, and
[30 min). We recorded the number of divers in the group
and the number of interventions made by the dive leader
when divers contacted benthic organisms or raised sediment onto corals. Corals were categorized to one of three
categories: (a) branching (e.g., fire coral Millepora alcicornis), (b) massive (e.g., Mussismilia braziliensis, M.
hispida, M. harttii, and Favia leptophylla), and (c) gorgonians (e.g., Phyllogorgia dilatata). Contacts with other
organisms (e.g., invertebrates) were also recorded. Diver
behavior was classified as intentional or unintentional. An
intentional contact is one the divers were clearly aware of.
For instance, divers putting their hands on the coral to get
closer to an organism near the substrate.
Diver Profile
Age, gender, certification level, and experience were
recorded through registration forms required by the dive
operator or by an interview at the end of the visit. We
require to divers an oral authorization to include their data
in the survey. The experience (number of dives completed
in a lifetime) was grouped into four categories: (a) 1–25
dives; (b) 26–50 dives; (c) 51–100 dives; or (d)[100 dives.
Certification was categorized as one of the follow categories: (a) open water; (b) advanced open water; (c) rescue
diver; or (d) dive master or instructor.
Reef Types
The behavior of divers was quantified at six dive sites, each
categorized as one of the following three reef types:
(a) three shallow fringing reefs; Mato Verde, Portinho Sul,
and Lı́ngua da Siriba sites, maximum depth of 7 m; (b) two
pinnacle reefs: Faca Cega and Chapeirão da Sueste sites,
maximum depth of 20 m; and (c) one artificial reef; the
Rosalinda shipwreck, a 102 m length steel freighter
wrecked in 1955 in good conservation status, maximum
depth of 20 m. We do not verify reef complexity; however,
there are obvious differences in the topography of the three
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Environmental Management
reef types surveyed. For instance, pinnacle is predominantly a ‘‘wall reef’’ and shipwreck is a ‘‘tridimensional’’
reef. The differences in topography can be an influential
variable in diver behavior and contacts with the reefs
because the reef angle with respect to the diver can vary
(Rouphael and Inglis 1997).
Table 1 Summary of diver profile
Fringe
Pinnacle
Artificial reef
Total
Male
26.8
16.1
16.2
59.1
Female
14.1
18.3
8.5
40.9
1–25 dives
11.8
7.9
7.2
27
26–50 dives
15.1
9.9
2.6
27.6
51–100 dives
9.2
7.9
5.3
22.4
[100 dives
7.2
7.9
7.9
23
Gender (%)
Experience (%)
Use of Additional Equipment
We assigned divers to one of five categories based on the
type of equipment they used, in addition to the regular
scuba set: (1) mini camera user (divers using small action
cameras, e.g., GoPro); (2) non-specialist photographer
(divers using compact digital cameras); (3) specialist
photographer (divers using professional cameras with
external flash greater bulk than compact cameras); (4)
sidemount users (divers using a gear configuration in which
two cylinders are mounted alongside the diver, below the
shoulders and along the hips, instead of on the back of the
diver); and (5) non-additional equipment users.
Data Analysis
Poisson regression and Kruskal–Wallis test were used to
verify relationships between diver profile, dive site characteristics, and contact rates. A multivariate analysis of
variance was used to explore relationships between both
the rates of touches and breakages on benthic organisms
per minute, using seven independent variables: (A) certification; (B) diver’s experience; (C) gender; (D) type of reef;
(E) use of additional equipment; (F) group size: 2–4 divers;
5–6 divers, and 7–9 divers; and (G) dive timing 0–10,
11–20, 21–30, and [ 30 min. To find the best set of
explanatory variables, we used the model selection procedure of stepwise backward elimination of non-significant
factors. The selection started with a model with all variables, and then dropped one variable at a time to test if the
variable deletion improved the model. We repeated this
process until no further improvement was possible (Zuur
et al. 2007). All tests were performed at a significance level
of P \ 0.05. Statistical analyses were performed using R
2.15.0 software (R Development Core Team 2012).
Results
Diver Profile and Contacts with Benthic Organisms
We observed 142 divers (57 on fringe reefs, 50 on pinnacles reefs, and 35 on the artificial reef). The total observation time was 87 h and 16 min. The majority of divers
were male (59 %; Table 1). Seventy percent of divers
possessed open water or advanced open water diving
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Age (%)
Certification level
10–20
6.8
Open water
63
21–30
23
Advanced open water
37
31–40
31.8
Rescue diver
19
41–50
20.3
Dive master
[50
18.2
Instructor
9
14
certifications. Diver experience ranged between 2 and 700
dives. The modal diver experience category was 26 to 50
dives, followed by 1 to 25 dives (27.6 and 27 %, respectively; see Table 1). Fifty-eight percent (N = 83) of divers
used additional equipment. Of these, 28.9 % were mini
camera users, 32.5 % non-specialist photographers, 20.5 %
were specialist photographers, and 18.1 % were sidemount
users. The experience of mini camera users varied between
10 and 550 dives, with an average of 138 ± 18.5 (±SE), of
non-specialist photographers varied between 6 and 1200
dives (average = 113 ± 23), of specialist photographers
varied between 10 and 550 dives (average = 141 ± 17.1),
and of sidemount users varied between 10 and 500 dives
(average = 156 ± 19.2).
Most divers (88 %, N = 126) contacted benthic organisms at least once during each dive. Of these, 46 % of
divers touched, 37 % damaged, and 17 % raised sediment
onto benthic organisms. The overall average of contacts per
minute was 0.26 (SD = 0.25), and considering that a single
dive lasted on average 39 min, each diver contacted benthic organisms 10.4 times per dive, represented by 8.19
touches, 1.04 damages, and 1.17 raising sediment.
Additional equipment users accounted for 54 % of all
contacts. Overall, a minority of divers accounted for the
highest contact rates (Fig. 1). Ninety-two percent of all
contacts (N = 1324) were unintentional. Most of contacts
occurred during the first 20 min of dive (69 %, N = 67).
Divers contacted benthic organisms with their fins (79 % of
total, 7.5 ± 0.6 contacts per dive); hands (11 %,
1.06 ± 0.09), scuba gear (6.5 %, 0.55 ± 0.04 contacts per
dive); and knees (3.6 %, 0.36 ± 0.04 contacts per dive).
Intentional contacts were caused mainly with hands (85 %,
Environmental Management
Fig. 1 Frequency of diver
contact rate with benthic
organisms (N = 142)
N = 94). Table 2 details the number of contacts and how
they occurred. Massive corals were the most touched, and
branching corals the most damaged (74 and 59 %,
respectively). Both were contacted mainly by fin kicks. All
events of raising sediments were caused by fin kicks,
mainly in massive corals (79 %). Sixty-six percent of
damages occurred in branching corals and 21 % in massive
corals. Dive leader intervention was observed in only 2 %
(N = 29) of contacts.
Effects of Reef Type, Additional Equipment Use,
Timing, and Group Size on Diver Behavior
The highest rates of diver contacts with benthic organisms
were observed on the artificial reef, followed by pinnacle
reefs (Table 3). Artificial reefs had the shorter dive time
average (* 4 min) than dives on the natural reefs, but
received the highest rates of touch, damage, and raising
sediment events per dive. No significant relationship was
verified between diver experience and contact rates per
Table 2 Diver contact rate
with benthic organisms in the
Abrolhos National Marine Park
minute on fringe reefs (Poisson regression I = -1.57,
P = 0.7), pinnacle reefs (I = -1.51, P = 0.9), and on the
artificial reef (I = -0.86, P = 0.6; Fig. 2). However, in
the artificial reef, the rate of contacts tended to increase
with greater experience. For all reef types, specialist
photographers and sidemount users obtained significantly
more contact rates than mini camera users and nonspecialist photographers (Kruskal–Wallis test P \ 0.01)
and non-additional equipment users (P \ 0.001; Fig. 3a).
Mini camera users caused the lowest contact rates,
(0.15 min-1 ± 0.02), even lower than non-additional
equipment users (0.18 min-1 ± 0.02). Specialist photographers and sidemount users caused highest contact rates
(0.38 min-1 ± 0.06 and 0.50 min-1 ± 0.07). A similar
pattern was verified when contact type was analyzed
according to additional equipment. For instance, specialist
photographers and sidemount users caused the highest rates
of touch and damage over all reef types.
Multiple analysis of variance revealed that reef type, use
of additional equipment, and dive timing were important
Branching coral
Massive coral
Gorgonians
Other organisms
N
Per dive
N
Per dive
N
Per dive
N
Per dive
164
1.15
720
5.07
23
0.16
77
0.54
14
0.10
4
0.03
Touch
Fin
Hand
17
0.12
108
0.76
3
0.02
Knee
1
0.01
44
0.31
0
0
Scuba gear
4
0.03
53
0.37
3
0.02
3
0.02
186
1.31
925
6.51
29
0.20
98
0.69
Fin
88
0.62
16
0.11
1
0.01
8
0.06
Hand
86
0.04
0
0
0
0
2
0.01
Knee
1
0.01
0
0
0
0
0
0
Scuba gear
2
0.01
9
0.06
0
0
4
0.03
97
0.68
25
0.18
1
0.01
14
0.10
Total
Damage
Total
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Environmental Management
Table 3 Diver contact rate with benthic organisms according to reef types
Frequency (per minute)
Average number of contacts over a dive
Fringe
(mean ± SE)
Pinnacle
(mean ± SE)
Artificial reef
(mean ± SE)
Fringe (average dive
time of 41 min)
Pinnacle (average dive
time of 39 min)
Artificial reef (average
dive time of 37 min)
Touch
0.13 ± 0.013
0.17 ± 0.02
0.33 ± 0.04
5.33
6.63
12.21
Damage
0.01 ± 0.003
0.02 ± 0.004
0.05 ± 0.009
0.41
0.78
1.85
Raising
sediment
0.03 ± 0.006
0.02 ± 0.006
0.05 ± 0.02
1.23
0.78
1.48
(X2 = 24.5, df = 3, P \ 0.05), pinnacle (X2 = 56.8,
P \ 0.05), and the artificial reef (X2 = 14.4, P \ 0.05).
Divers in the first 10 min caused more than four times as
many contacts as fringe and pinnacle reef types, and more
than twice compared with the end stage of the dive (Fig. 3b).
Group size did not reveal significant differences to contact
rates.
Discussion
In this study of diver contacts on benthic organisms, we
found that on an average dive, divers contacted the reef
10.4 times. However, our analysis indicates that variability
in contact rates was influenced mainly by additional
equipment use, reef type, and timing. In the sections below
we discuss the influence of each variable on diver contacts
with benthic organisms.
Reef Type
Fig. 2 Relationship between diver contacts rates with benthic
organisms and diver experience according reef type
factors explaining touch and raising sediments rates
(Table 4, ANOVA F = 15.44, P \ 0.001, R2 = 0.188) and
damage rates (F = 7.721, P \ 0.001, R2 = 0.097). More
specifically, the combination of factors that predicted the
highest rate of touches and damaged was specialist photographers, sidemount users, diving in the artificial reef during
the beginning of their dive (Table 4). The diving time
between 11 and 20 min was also negatively correlated with
touch rate. The significant difference in the end stage of
diving (21 min upward) on diver contacts with benthic
organisms was consistent over the three reef types: fringe
123
The artificial reef obtained twice the rate of diver contacts
with benthic organisms than fringe or pinnacle reefs. The
Rosalinda shipwreck has a complex structure, with a high
abundance of corals along its extension. The high complexity and high abundance of corals in the parts of wreck
most visited by divers (e.g., the command deck and vessel
edges) make these areas susceptible to higher contact
rates. Another reason for the high rate of contact in the
artificial reef is that dive leaders often deliberately contacted corals. This behavior was frequently repeated by
visitors, resulting in a higher rate of contacts. It is well
known that divers tend to mimic the behavior of their
dive leaders (Barker and Roberts 2004). When asked to
justify this behavior, dive leaders explained that they were
not as concerned about corals in the shipwreck, as they
perceived the artificial reef as a non-natural environment.
The Rosalinda shipwreck is one of the main attractions of
ANMP and diving may continue to occur there with or
without the coral presence. However, after a period
between 8 and 25 years, artificial reefs, if undisturbed,
Environmental Management
Fig. 3 a Number of dive contact rates of non-users of additional
equipment (white box), users of photographic cameras (light gray
boxes), and users of sidemount (dark gray box). b Contacts made
according dive timing. Boxes represent the interquartile range,
containing 50 % of the figures. The line across the box indicates
the median. The dashes represent the 5th and 95th percentiles and the
filled circles are the extreme figures
have demonstrated the same level of biodiversity and
productivity as other natural reef ecosystems (Burt et al.
2009; Perkol-Finkel et al. 2006). Frequent diver contact
on shipwrecks not only cause impact on benthic organisms but may also expose the metal framework of the ship
to the seawater, accelerating corrosion (Jewell 2004;
McKinnon 2015). Environmental education training for
dive leaders and other management interventions are
needed to conserve the benthic organisms of ANMP. A
successful initiative that should be used to inspire similar
action is the National Oceanic and Atmospheric Administration’s (NOAA) Blue Star programme in Florida,
which trains and incentivizes dive leaders to include
conservation education into their dive briefing, aiming to
reduce diver impacts on the reefs (Camp and Fraser
2012). Dive shops also benefit from this endeavor,
because its positive results (see Camp and Fraser 2012;
Krieger and Chadwick 2012) can be used as marketing
tool as the society is becoming more environmentally
aware.
Additional Equipment Use
It is not surprising that specialist photographers inflicted
most of the damage to benthic organisms in this ANMP,
since this diver type has previously been shown to cause
more damages to benthic organisms elsewhere (Worachananant et al. 2008; Luna et al. 2009). Specialist
photographers are often too distracted with their subjects to
paying attention to the reef. They also use the reef to steady
themselves and get closer to their subjects. The contacts
they made caused more damage than those made by nonphotographers (Rouphael and Inglis 2001; Barker and
Roberts 2004; Krieger and Chadwick 2012). On the other
hand, mini camera users obtained the lowest contact rates.
Mini cameras have become popular in underwater
videography due of its small size, low-cost, standardized
housing, and widespread availability. Mini camera’s users
usually have a rod with the camera attached at the tip, and
so the diver does not need to approach the bottom to
capture a subject.
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Environmental Management
Table 4 Multivariate analysis
of variance results showing
factors with significant
influence on divers’ contact
rates with benthic organisms
Unstandardzed coefficients
Standardised coefficients
b
b
SE
t
P
Touch
(Intercept)
6.892
<0.001
0.228
5.424
<0.001
0.035
0.853
0.4
-0.017
-0.409
0.7
0.064
1.554
0.12
0.146
3.566
<0.001
0.235
5.724
<0.001
-0.124
-2.687
0.007
-0.207
-4.472
<0.001
-0.323
-6.949
<0.001
3.620
<0.001
0.180
4.076
<0.001
0.027
0.626
0.5
0.014
0.330
0.7
0.024
0.557
0.5
0.129
2.994
0.002
0.123
2.834
0.004
-0.041
-0.852
0.4
-0.192
-3.921
<0.001
-0.235
-4.796
<0.001
0.252
0.036
Reef type
Artificial reef
0.198
0.036
Pinnacle
0.027
0.032
Additional equipment
Mini camera user
-0.016
0.040
Non-specialist photographer
0.062
0.040
Specialist photographer
0.165
0.046
Sidemount user
0.274
0.047
Dive timing
11–20 min
-0.107
0.039
21–30 min
-0.178
0.039
[31 min
-0.281
0.040
Damage
(Intercept)
0.027
0.007
Reef type
Artificial reef
0.030
0.007
Pinnacle
0.004
0.007
Additional equipment
Mini camera user
0.003
0.008
Non-specialist photographer
0.004
0.008
Specialist photographer
0.028
0.009
Sidemount user
0.028
0.009
Dive timing
11–20 min
-0.007
0.008
21–30 min
-0.032
0.008
[31 min
-0.049
0.008
The best model for touch and damage used the variables reef, additional equipment, and timing. The
table shows the coefficient’s estimates of variables (b), standard error (SE), t statistic (t), and probability
(P). Coefficients in bold indicate significance (P \ 0.05). Reference level for this regression was set as
‘fringe’ for reef type, ‘non-user’ for use of additional equipment, and ‘0–10 min’ to dive timing. For the
analyses purpose, we added raising sediments rates to the category touches
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Environmental Management
Sidemount users also inflict a high rate of damages. This
diving configuration, previously restricted primarily to the
technical diving community, is becoming popular among
recreational divers in Brazil relatively recently and most
users may still lack the skills necessary to avoid reef contacts. Clearly, further research is needed to understand the
effects of this equipment in divers’ behavior and impacts in
the marine biota.
Dive Timing
For all of the reef types analyzed in this study, contact rates
were higher during the first 10 min of the dive. Previous
studies have verified that the beginning of the dive is considered critical with respect to diver-coral contact rates (Di
Franco et al. 2009; Camp and Fraser 2012; Krieger and
Chadwick 2012). In this stage, divers are performing adjusts
to establish neutral buoyancy and navigation (Di Franco et al.
2009), and organizing pair formation (VJ Giglio, personal
observation). Starting dives over sandy bottom areas or in
sites with low coral cover could help mitigate the impacts of
recreational diving. The rate of diver’ contacts with benthic
organisms decreased as the time of dive increased, because
over time then divers usually established better buoyancy
control and navigation.
Diver Profile and Group Size
Experienced divers are more familiar with marine environment and have undertaken more extensive training.
This in turn increases their diving skills, such as buoyancy
and swimming control (Ong and Musa 2012; Davis and
Tisdell 1995). In this context, we predicted that experienced divers would make fewer contacts with corals.
However, we did not observe a negative relationship
between diver experience and contact rates. A similar
finding was reported by Rouphael and Inglis (2001), who
did not verify such correlation either. This can be
explained by inexperienced divers being more fearful of
getting close to the bottom during scuba diving activities
and touching what they assume to be harmful. On the
other hand, experienced divers may feel more comfortable to get close to the substratum and handle organisms.
However, our results must be interpreted carefully
because the relationship between diver experience and
contacts with benthic organisms may vary according to
additional equipment type. It was not possible to assess
this parameter because we did not have a wide range of
experiences for all additional equipment and reef types.
Our results highlight a contradiction in the relationship
between diver experience and their behavior. Diving
management strategies with constraints based only on
certification and experience may be inefficient. The higher
individual contact rates were influenced mainly by the use
of additional equipment, not experience.
Group size did not have influence on diver contact rates
with the reef. In a scenario where dive leader intervenes
when observe divers touching reefs, we expected that
smaller groups cause lower contact rates. However, in
ANMP, dive leaders intervene or warn divers when they
touch organisms only in 2 % of the events. In a previous
study, interventions made by dive leaders were successful
to reduce diver-coral contacts by as much as 80 % (Barker
and Roberts 2004). However, in dive sites in Florida
(Krieger and Chadwick 2012) and in the ANMP, dive
leaders serve primarily as tour guides and tend to stay at the
front of the group, looking ahead. Recreational diving can
be more sustainable in the ANMP if dive leaders observe
divers more closely, and intervening when seeing they are
damaging benthic organisms.
Contacts with Benthic Organisms
The high percentage of divers that contacted benthic
organisms observed in this study (88 %) was consistent
with findings at other sites, where most divers made one or
more contacts per dive. On Australia’s Great Barrier Reef,
70 % of surveyed divers contacted with corals (Rouphael
and Inglis 2001). In the Florida,USA, and Bonaire, 75 % of
divers contacted the reef (Krieger and Chadwick 2012;
Uyarra and Côté 2007). Overall, in ANMP, contact rates
occur at an average of 0.26 min-1, 8.72 touches and 0.9
damages per dive. This result is lower than observed in
Florida, US (0.33 contacts min-1 and 17.9 per dive) and
Hong Kong (0.87 contacts min-1 and 14.6 per dive)
(Chung et al. 2013). In Australia, Roberts and Harriot
(1994) observed an average of 35 contacts and 2.45 damages per dive. The ANMP has a relatively low abundance
of benthic organisms when compared with dive sites surveyed described above that covers between 30 to 70 %.
The benthic organisms cover in ANMP is of approximately
10 % for the main coral species, M. braziliensis, 3.5 % for
Siderastrea sp and 1 % for M. harttii (Francini-Filho et al.
2013). On the other hand, the lower abundance of benthic
organisms in the ANMP may explain the apparent lower
rate of diver contacts because they simply have fewer
opportunities to contact them.
The majority of contacts with benthic organisms in the
ANMP were through unintentional fin kicks, caused by
poor swimming techniques and lack of buoyancy control,
indicating poor diving proficiency. Fin kicks are the main
cause of scuba diving coral damages (Medio et al. 1997;
Rouphael and Inglis 1995, 1997; Luna et al. 2009; Chung
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Environmental Management
et al. 2013). Many divers are not aware that they had
touched the reef, particularly with their fins (Poonian et al.
2010) or do not know about diving impacts on corals
(Walters and Samways 2001). Unfortunately, most dive
tourism destinations lack information on acceptable levels
of contacts with the reef. Sites with higher densities of
branching corals are more susceptible to diving damage
because they break easily (Worachananant et al. 2008). A
lower visitation rate is recommended for sites with a
greater abundance of branching corals than sites that
mainly consist of massive corals (Riegl and Riegl 1996;
Schleyer and Tomalin 2000).
Is Diving Pressure in the ANMP Sustainable?
Approximately, 1300 scuba divers annually visit the ANMP
and each diver performing on average seven dives, totalling
9100 dives per year divided between 15 dive sites. Using this
visitation rate and the contact rates determined in this study,
we estimate that divers touch on corals 74,529 times cause
damage 9464 times and raising sediment onto corals 10,647
times per year. Diving pressure in ANMP lies below limits
considered to be sustainable (5000–6000 dives per year;
Hawkins and Roberts 1997), with a maximum of approximately 2500 annual dives per site. However, despite the wide
adoption of proposed diving carrying capacity for reefs
worldwide, this number varies according to diver behavior
and site-specific biophysical characteristics of the reef.
These characteristics include use intensity, coral growth, the
presence of vulnerable species, and reef topography (Hawkins and Roberts 1997; Zakai and Chadwick-Furman 2002;
Barker and Roberts 2004). Thus, the resilience of coral reefs
can vary substantially, even within the same MPA (Hughes
and Connell 1999). Coral reefs of ANMP consist of a relic
coral fauna with Brazilian endemic forms dating back to the
Tertiary time (Leão and Kikuchi 2005). Some species have
adapted to water turbidity caused by carbonate and siliciclastic sedimentation (Leão and Ginsburg 1997; Leão et al.
2003). Therefore, the determination of a carrying capacity
that considers site-specific characteristics is an essential
strategy to managing diving tourism.
Diver pressure and contacts with benthic organisms
made by ANMP divers are lower than observed in other
studies. Despite this, it is evident that the promotion of
sustainable use is a necessary approach within dive tourism management. Long-term monitoring of corals health
and visitation rates is one way to effectively assess diver
impacts and to introduce regulation as necessary. We
suggest the adoption of five management measures to
reduce coral damage caused by divers in ANMP: (1)
establishment of a diving carrying capacity, through a
study that considers diver profile and site-specific biophysical characteristics of the reef; (2) provide pre-dive
briefings that include ecological aspects of corals, alerting
divers on impacts that diving can cause, and alerting
specialist photographers and sidemount divers to take
extra care; (3) increase the number of dive leader interventions when divers contacted corals, especially careless
or unskilled divers; (4) conduct trainings with dive leader
with focus on recreational diver impacts and cultural and
environmental importance of historical artificial reefs; and
(5) start dives over sand bottom or areas of low coral
abundance. Sites with the highest coral vulnerability (ex.
high cover of branching corals) should be visited when
divers have demonstrated good buoyancy control. These
strategies could be implemented with cooperation and
support of recreational diving stakeholders such as governmental agencies, MPAs managers, and diving operators. The future of recreational diving is largely dependent
on the health of reef resources and their management is
essential to conserve the biodiversity of coral reefs.
Acknowledgments We thank dive shops Horizonte Aberto, Apecatu Expedições, and Parú Divers for the support; dive guides V.
Albanez, M. Lana, J. Andrade, M. Affonso, T. Ramon, T. Bonelli, R.
Santoro, D. Cajueiro, M. Kipgem, and E. Said. J. Adelir-Alves for
support in data collection; Abrolhos National Marine Park (through R.
Jerozolimski) for research permission and support; and C. Sampaio,
C. Cassano, and W. Goodell for suggestions on manuscript. The first
author was supported by the Brazilian Ministry of Education
(CAPES) and AS was supported by Ministry of Science and Technology (CNPq).
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