The human inhabitants of Solomon Islands, like many Pacific islands, are heavily reliant on coastal fisheries for food. With increasing human population, there is concern that capture fisheries will not be able to continue to meet demand. Development of aquaculture for species such as milkfish has been suggested as a potential mitigation for this deficit. However, as a recently published report on a four-year study, led by Dr Reuben Sulu (WorldFish) demonstrates, the feasibility of developing a milkfish aquaculture industry on the Islands goes beyond technical issues.

Found in Solomon Island waters, milkfish has been popular with a number of Island communities. With milkfish possessing a number of aquaculture-favourable characteristics such as fast growth rates and their invertebrate and algal based die, it is unsurprising that aquaculture of milkfish has garnered attention by small-scale farmers, and those interested in larger commercial development.

Ideally, milkfish aquaculture would rely on hatchery-production of fry. Unfortunately, due to the financial costs of running such facilities, the government-led National Aquaculture Development Plan (2009–2014) noted that hatchery development “is not presently envisaged”. Fortunately for those interested in milkfish aquaculture, Dr Sulu and colleagues demonstrated that milkfish fry is available in Solomon Island waters, and that this fry can be successfully reared to a harvestable size with technology and resources available locally.

On one side this means dependence on wild populations still remains.  On the other, economic and employment opportunities arising from fry collection could be realised.   Other positives include the potential for locally-produced feed for milkfish aquaculture.  With the majority of people participating in the study being Solomon Islanders, milkfish aquaculture expertise is locally available – and the skills required can be fairly easily transferred to other aquaculturalists. 

The report outlines a number of challenges to milkfish aquaculture development.  Whilst wild fry may be available in a number of locations, not all places are easily accessible for collection.  Furthermore, accessible locations may not be able to supply the quantities required for widespread subsistence or commercial aquaculture. 

Customary ownership laws also add further complications.  All milkfish fry occur in areas under customary law, meaning someone effectively owns the fry – and has the right to control their capture and distribution.  Where aquaculturalists are not owners of such locations, negotiation would be needed to obtain and distribute fry within and between provinces. 

The biggest challenge for milkfish aquaculture may be its economic viability.  Where subsistence aquaculture relies on household members to operate the farm, and is located near a natural fry resource, milkfish production may be economically viable.  Under this scenario, most of the fish produced is eaten by the household, with only a small portion sold “at the gate”.  Once a farm enters commercial production, and/or is located far from a fry resource, increasing costs reduce the viability of milkfish aquaculture.  Due to economies of scale, small-scale commercial ventures are likely to be the least profitable, suffering longer payback periods and greater chance of financial loss than large-scale operations. 

Part of the economic problem lies with market opportunities.  Whilst popular in some communities, on a wider scale wild milkfish generally has a low consumer preference, with other species typically selling faster than milkfish.  Commercial milkfish aquaculture runs the risk of flooding the market, potentially forcing prices of milkfish to be lowered to encourage sale.  Furthermore, demand for milkfish is currently being met by capture fisheries which, with lower running costs than aquaculture, also caps the price aquaculture milkfish could be sold for. 

With aquaculture of milkfish currently proving unfeasible, the researchers suggest that the Government of Solomon Islands should consider alternate aquaculture species, such as Mozambique tilapia.  Nevertheless, they caution that the costs associated commercial aquaculture, particularly in light of competition from capture fisheries and indeed imported alternatives, has implications for the economic viability for any aquaculture development in Solomon Islands.

This story appeared on The Fish Site.