Rejuvenation of Hawaiian FishpondsPart 1. Reproduction of Hawaiian Oysters Part 2. Extension Services on the Big Island

Daren GarriquesJr. Extension Agent

Center for Sustainable Aquaculture

Potential Resource

• Hawaii fish ponds have long history of aquaculture

• Historical records indicate fish and inverts were harvested

• Modern times the remaining fish ponds represent an important resource for – Science, self-sustainability and cultural identity

He`eia Fishpond:

Photo by Paepae o He`eia

Past 3 years• Oyster hatchery work• Spat collectors trials, C. gigas growth trial data

collection • D. sandvicensis reproductive biology and

framing

•Tours and community outreach•Aquaponics implementation and technology transfer to schools •Mullet hatchery and distribution

Past 4 months

D. sandvicnesis• 2 to 5 cm in size and ~ 1 to 2 cm in depth• Related to European oyster (O. edulis) and

other tropical small oyster like Caribbean osyter (D. frons)

• Fossil record common to all Hawaii island

Importance of D. sandvicensis

• Endemic to Hawaii • Ecological role of bivalves– Precipitation of suspended solids• In lagoons & estuaries

– Reef building

• Possible aquaculture product • Future application for monitoring pollutants

Gametogenic cycle importance• Base line information– Aquaculture – Other endemic bivalve might be similar

• Future studies – Larvae recruitment– More parameter to characterize this endemic

species– Ecological role studies– Toxicology studies of coastal waters

Possible seasonal patterns of reproduction of D. sandvicensis

• Temperate and boreal species of bivalves show a period of reproductive activity usually during early spring.

• Subtropical species usually are more active during high food abundance in spring and summer

• Tropical species are usually more active in spring and summer months but can also be active in fall and winter months.

Spat collectors placing and monitoring at He’eia

• January 2009 Spat collection bags set at fish pond

• February to June 2009 bags were checked for signs of spat (once per month)

• Substrate used in trial was not colonized

Methods

• Once a month for a year samples (oysters) are collected from He’eia fish pond Oahu

• Two different groups collected at same time for:– CI ratios (30)– GS histology (12)

Field sample collection

CI Samples

Histology

Results

Results cont.

D. Sandvicensis reproductive cycle

• Tropical pattern– CI lower is significant lower in summer months

samples– GS 1 is more significant present in summer

months samples

• Adapted for year around spawning/brooding– GS1 present slightly in Fall and Winter months

C. gigas growth trial data collection 2009

Oyster hatchery work

• C. gigas 2009-2010– Experience gained on all aspects of seed and spat

production • D. sandvicnesis – 2009 (wild stocks) • Spawning, brood collection, larvae rearing and setting

trials– 2010 (wild and F1 stocks)• Brood collection, larvae rearing, setting and growth

trials

Larvae collector

Spat 2 weeks old

Larvae 2 days old Adult 2 years old

D. Sandvicensis culture system

2011 mullet hatchery and extension work

Mullet hatchery work• Hatchery set up• Trials for spawning– Winter spawning trials– Conditioning 6 females – Summer trials ( late June early July 2011)• Monitoring • Spawning

• Fingerling production• Distribution and technology transfer

Mullet hatchery

Winter Spawning trial

• 3 trials– January 28– February 3– February 17

• 1-1.5 million eggs per female

• No fertilization

Conditioning

• 18 fish– 6 females– 12 unkown

• Artificial photoperiod– 1 year into 6 months– Increments in 15 to 30

minutes– First check for mature

females in late May 2011

Extension to fish ponds• Currently identifying obstacles for mullet

production– Literature research management of fry– Life feed production

• Once successful spawning is achieved– Fingerling transportation– Stock densities

Aquaponics

Aquaponic system PACRC

Aquaponic in construction forKeaukaha elementary

Ocean Day at PACRC

Tours

# of Tours 22

Schools 17

Private 5

Total Adults 148

Total students 254

Total 402

Mahalo!