Coconut Crabs as a Target for Promoting the Establishment of Marine Protected

Areas on Green Island, Taiwan

C.P. Chen1,2,3, S.T. Lin2,3, F.L. Wang1

1 Institute of Fishery Science, National Taiwan University, Taiwan2 Institute of Zoology, Academia Sinica, Taiwan3 Research Center for Biodiversity, Academia Sinica, Taiwan

Marine Protected Area (MPA)

MPA establishment combining local community and ecosystem

Local Community Coconut Crabs

Green Island

Local empowerment

Conservation

Green Island introduction

History Ecology

• Coral reef ecosystem

Hard corals:176 spp.

Soft corals:27 spp.

Fishes:602 spp.Green Island

Map of Green Island.

16.2 km2

3200 people Mountain peak of Green Island is 281m

Photos available at http://green.taitung.gov.tw/caption/ca_page1.asp

A threatened species, list on the Red list of the International Union for the Conservation of Nature (IUCN) since 1983

Protected by the Wildlife Conservation Law in Taiwan since 1995.

Coconut crab, Birgus latro .

Coconut crab, Birgus latro

Phylum Arthropoda Class Crustacea Order Decapoda Infraorder Anomura Family Coenobitidae Genus Birgus

Birgus latro (Linnaeus, 1767)

1 mm

1 cm

10cm

Zoeal stages

Glaucothoe

Juvenile crab

1 mm

Metamorphosis

Spawning

Adult

Ⅰ

Ⅱ

Ⅲ

Ⅳ

Ⅴ

Rocky coastsOcean

Emergence

Life history of the coconut crab, Birgus latro.

Why we choose coconut crabs as an umbrella species of Green Island?

Relationship between coconut crabs and local residents– as children’s pet in early days

The ecological importance of coconut crabs, including:– large body size

– Unique ecological niche

– long life history

– the unique life of this migrating species, as adults occur in terrestrial mountain areas

Successfully conserving the habitat of coconut crabs will not only protect the coastal zones and nearby waters, but also land areas

Threats to coconut crabs on Green Island

• Illegal harvesting

— population of coconut crabs declined rapidly.

• Too many infrastructures

— harm its habitats and block its spawning pathway.

• Environmental deterioration

— habitat fragmentation

Current tourism state of Green Island

0

50

100

150

200

250

300

350

400

1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003

Year

Thou

sand

per

sons

Number of tourists visiting

Green Island from 1991 to 2003 Carrying capacity:

2000 persons/day

(Calculating by ECG international,

1993)

SARS

Number of monthly tourists

from 1991 to 2003July is the peakAveraged of last five July is

64,077 persons

0

10

20

30

40

50

60

70

80

1 2 3 4 5 6 7 8 9 10 11 12

Month

Tho

usan

d pe

rson

s

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

Three actions for coconut crab conservation

• Basic survey and larval culture of coconut crabs

• Habitat conservation

• Local community empowerment through education

Basic survey of coconut crabs

1 mm

10cmZoeal stages

Glaucothoe

Juvinile crab1 mm

Metamorphosis

Spawning

Adult

Ⅰ

Ⅱ

ⅢⅣ

Ⅴ

Rocky coasts

Ocean

Hard to conduct the population survey!

Capturing female coconut crabs

Spawning area

Temperature: 24-25℃ Salinity 34-35‰. fed with hatched Arte

mia nauplii

Larval culture of coconut crabs

The mean survival rates of zoeae fed with enriched Artemia nauplii are higher than unenriched groups in each zoeal stages.

1 mm

Glaucothoe of coconut crab hiding in a snail shell.

20 Zoea metamorphosed to glaucothoes on the 27th to 34th day

6 carrying the shell on the 37th to 43rd days of its zoeal life.

Larval culture results in 2004

Habitat conservation

• Maintain habitat diversity

Adults Juvenile

larva

Habitat conservation

• Avoid habitat fragmentation

The road circling Green Island, cuts the migration routes of hermit crabs

Local community empowerment through education

Framework of the coconut crab conservation team's works on Green Island.

Environmental education

Seizure of illegal harvest

Habitat preservation

Artificial culture

collecting the culture and history of coconut crabs and local residents

local educational institutions local residentsgovernment organizations

MPA

Coconut crab conservation team work

Development the eco-tourism subject to coconut crabs

Coconut crab conservation team

Team members including teachers from local schools, government officials, police and local residents.

Objectives1. Environmental education

2. Stopping illegal harvesting

3. Habitat preservation

4. Artificial culture

5. Information collection

6. Ecotourism development

Environmental education at Green Island elementary school in 2003.

Coconut crab booklet, emphasizing the relationship among coconut crabs and their natural environments on Green Island.

Coconut crab postcard. (a) The front of the postcard emphasizes the life history and habitats,(b) The back of postcard states the law and punishment.

(a) (b)

Propositions of coconut crabs conservation

• Ecological corridors for crabs.

• Enforcement of conservation laws.

• Promoting environmental education and

local communication.

• Continuing research on artificial culture

• Protecting the entire habitat of coconut

crabs, from the mountains to the sea.

Outlook for the MPA and creation of an Eco-island

• MPA

– MPA proposed emphasizing both ecological and

social aspects.

– Local participation on the planning and managing

process of MPA.

• Eco-island

– Conservation actions start from protecting coconut

crabs.

– Maintain biodiversity, and habitat integrity

– Develop Ecotourism.

– Wise and sustainable use natural resources.

Girl with coconut crab

Painted by Y. W. Ou, 1961

Thank you