Update on aquaculture activities in the Marshall Islands (06/2007)
Friday, 01 June 2007 00:00

By Ben Ponia and Antoine Teitelbaum

 

Aquaculture in the Marshall Islands is relatively diverse. Although much of it occurs on a small scale, there are a number of interesting developments on Wotja Atoll. Ben Ponia and Antoine Teitelbaum report on the situation in the Marshall Islands.

 

The Woja hatchery: Spawning pearl oysters and diversifying to finfish

 

The pearl oyster hatchery at the Marshall Islands Marine Resources Authority (MIMRA) on Wotja (formerly owned by Black Pearls of Micronesia) is the main source of spat for pearl farms operating in the country. This hatchery has struggled to produce sufficient numbers of spat — a major bottleneck to pearl development in the Marshall Islands.

 

The hatchery has recently been fully refurbished and equipped with water quality treatment equipment such as a settlement tank and UV filters. Plumbing and pumping systems were also renewed and hatchery tanks rearranged to make the hatchery more efficient.

 

Unfortunately, even after refurbishment, MIMRA’s first spawning runs crashed continuously at the larval stages. After a lengthy process of elimination, and trial and error, it was discovered that a dosage of EDTA (a heavy metal chelating agent) was necessary for successful spat settlement. However, the use of EDTA still points to discerning signals in lagoon water quality. The last hatchery batch produced by MIMRA consisted of several thousand oysters and was provided to the Robert Reimers Enterprises farm (on Jaluit) and Black Pearls of Micronesia farm (on Arno). Technically, the hatchery has the capacity to produce several hundred thousand spat, which is enough to meet the needs of the Marshall Islands. A two-year grant by the Center for Tropical and Subtropical Aquaculture has just been approved to overcome bottlenecks in spat production and run experiments on transportation methods to increase survival.

 

MIMRA expatriate staff member, Provan Crump, based at the Wotja hatchery has trained local technicians in operating the hatchery and carrying out larval rearing. As a result, the operation is now mostly run by skilled Marshallese staff.

 

Recently, the Australian company, Good Fortune Bay Fisheries, a large and reputable aquaculture operation based in Bowen, Queensland, has imported juvenile humpback groupers (Cromileptes altivelis). The intention is to collaborate with MIMRA on an aquaculture joint venture for growing-out humpback groupers in cage systems in Majuro's lagoon.

 

MIMRA has been holding the fingerlings in a simple quarantine facility located at the Wotja pearl oyster hatchery. So far, the trial has demonstrated that shipping by air from Australia to the Marshall Islands is a success as there was virtually no mortality and the fingerlings have adapted very well and shown good growth rates. No signs of disease have been observed.

 

Floating cages are being put together by Good Fortune Bay Fisheries and MIMRA experts. The fish will be grown-out in Majuro's lagoon near passes on the northern side, an area with pristine water quality and permanent oceanic water exchanges.

 

At this stage MIMRA still lacks aquatic biosecurity capacity for importing marine finfish and so have been working with the Marshall Islands Environmental Protection Agency on an import risk analysis. MIMRA will work with FAO on biosecurity training with SPC’s assistance.

 

Ongoing efforts in diversifying aquaculture at College of the Marshall Islands

 

The College of the Marshall Islands (CMI) science station has a simple hatchery with an algae lab and several 10-ton concrete tanks onsite. Recently, a five-year US Department of Agriculture project granted monies for pearl transshipments to other atolls, triploidy experiments, and monitoring plutonium levels in the oysters at Bikini atoll to assess radiation impacts from nuclear testing during World War II.

 

MIMRA and CMI could potentially be involved in a regional project, possibly involving Kiribati, Fiji and Cook Islands, to grow half pearls (mabe).

 

Marine ornamentals at the Marshall Islands Mariculture Farm

 

The Marshall Islands Mariculture Farm — owned by Ocean Reefs and Aquarium (Florida), and formerly owned by Robert Reimer Enterprises — operates 24 large concrete raceways and 48 smaller fibreglass troughs. Some lagoon grow-out is also coordinated by the technical staff of a farm on Arno Atoll. Giant clams (Tridacnae) are one of the mainstay export products although the farm also exports coral fragments (soft and hard corals).

 

Marine ornamental stocks also come from the outer Marshall Islands (e.g. clams from hatcheries at Likiep and Arno). The farm also holds and exports products from other countries such as soft corals from Pohnpei (Federated States of Micronesia).

 

High mortality levels in recent years have decreased the farm's exports. These mortalities are blamed on a disease and on poor water quality; the farm's water intakeare located just a few kilometres downstream from Majuro's dump.

 

Taiwan stepping into aquaculture in the Marshall Islands

 

The Taiwan Technical Mission in Majuro has recently begun construction of a fish hatchery in Laura. So far, four large (~ 20-ton) concrete tanks (to be used for spawning) and about 20 five- and two-ton tanks (to be used for larval rearing and as nurseries) have been built.

 

This project aims at culturing groupers (Epinephelidae) and rabbitfish (Signidae). There is also an interest in propagating tiger prawns (Peneus monodon). All of these could be grown for the small existing local markets for a start, and there may be potential for exporting them to markets in Hawaii, in the future.

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