ASK AND YOU SHALL RECEIVEREDUCING DIVER IMPACTS ON GUAM’S CORAL REEFS WITH A CORAL-SAFE DIVING REMINDER

Ashton Williams& Dr. Laurie Raymundo

University of Guam Marine Laboratory

Population: 160,000

Size: 544 km2Annual Visitors: 1.4 million

Resident divers: 30,000

Visitor divers: 140,000

GUAMGUAM

170,000How can we reduce the impacts of divers on

Guam’s coral reefs?

How do divers damage coral?

• Kick and bump corals

• Sit and stand on corals

• Grab corals

• Kick up sand/sediment clouds

• Intentionally damage corals

• Use sunscreens with chemicalsthat harm corals

Why do divers damage coral?

• Failure to streamline

• Too close to reef

• Poor buoyancy control

• Distractions

• Ignorance

How can we reduce the impacts of divers on

Guam’s coral reefs?

What if we reminded divers to practice

“coral-safe diving” before each dive?

Watch your buoyancy, and be careful to avoid

touching, bumping, or kicking the corals!

“Watch your buoyancy, and be careful not to touch, kick, or step on the corals!”

Photo: Mike Schuck

5-minute observation

• Substrate touched

• Body part used

• Intention

• Damage

• Camera & glove use

• Buoyancy control

Questionnaire

• Demographic data

• Socio-economic data

• Diving experience and

training

• Diving-related beliefs

and opinions

Finding #1: “Coral-safe diving reminder” works!

0

0,5

1

1,5

2

2,5

3

3,5

4

4,5

5

Reminder No Reminder Reminder No Reminder

# o

f C

on

tact

s

Accidental Contacts Intentional Contacts

Mean contacts per 5-minute observation period

p=1.10E-13 p=1.17E-13

• Kruskal-Wallis

• Highly significant

differences

Simple, easy,

cost-free tool to

reduce diver

impacts on coral

reefs!

Finding #2: Cameras & gloves = more reef contact

• Kruskal-Wallis

• Significant

differences

Divers with

gloves and

cameras should

be supervised

more carefully.0

0,5

1

1,5

2

2,5

3

3,5

4

4,5

5

Camera No

Camera

Gloves No

Gloves

Camera No

Camera

Gloves No

Gloves

# o

f co

nta

cts

Accidental Contacts Intentional Contacts

Mean contacts per 5-minute observation period

0

1

2

3

4

5

6

DSLR GoPro Point & Shoot DSLR GoPro Point & Shoot

# o

f co

nta

cts

Accidental Contacts Intentional Contacts

Mean contacts per 5-minute observation period

Finding #2: Cameras & gloves = more reef contact

• Kruskal-Wallis

• Significant

differences

Divers with

gloves and

cameras should

be supervised

more carefully.

p=0.003 p=0.003 p=0.002p=0.0004

p=0.01 p=0.0002

0

0,5

1

1,5

2

2,5

3

3,5

4

4,5

5

Guam Visitor Guam Visitor

# o

f co

nta

cts

Accidental Contacts Intentional Contacts

Mean contacts per 5-minute observation period

• Kruskal-Wallis

• Significant differences

for accidental

contacts, but not

for intentional

Finding #3: Visitors have more reef contact

• Mann-Whitney

• Significant differences

for both intentional

and accidental contacts

Visiting divers

should be

supervised more

carefully than

resident divers.p=4.95E-05 p>0.05p=5.19E-06 p=0.013

…but not all equally.

0

1

2

3

4

5

6

Asia North America Guam Asia North America Guam

# o

f co

nta

cts

Accidental Contacts Intentional Contacts

Mean contacts per 5-minute observation period• Kruskal-Wallis

• Significant differences

for accidental

contacts, but not

for intentional

Finding #3: Visitors have more reef contact

• Mann-Whitney

• Significant differences

for both intentional

and accidental contacts

Visiting divers

should be

supervised more

carefully than

resident divers.p=4.95E-05 p>0.05p=5.19E-06 p=0.013

…but not all equally.

Additional findings

• Briefing before 1st dive reduces contact on both dives

• Divers with poor buoyancy control make more accidental contacts

• Groups of 5 or more divers have more individual contacts

• Positive correlation between guide & client contacts

• Number of lifetime dives > certification level

• Divers are generally self-aware of skill level and buoyancy control

• Most divers want to know more about coral reefs

Takeaways & Implications

• Reminding divers to practice coral-friendly diving can reduce diver impacts on coral reefs

• Some divers should be supervised more carefully to reduce their impacts

• Diving professionals are willing to help

• Voluntary effort > regulations/laws

• Green Fins materials

• Divers want to learn—let’s help dive operators teach them!

Thank you & si yu'os ma’åse!

• Dr. Laurie Raymundo

• UOG Marine Laboratory

• Micronesian Diver Association

• Guam Visitors Bureau

• NOAA