Coastal, Domestic and Offshore Fisheries in the Cook Islands
The oceanic fish that migrate through the Cook Islands waters are fished by different fleets that include the coastal artisanal and sports charter fleets, and locally based and offshore longline fishing vessels.
The challenge for the Ministry of Marine Resources (MMR), as a resource manager, is to ensure that fishing is sustainable whilst minimising interactions amongst fishers to optimise catches of target species. To look at fishing patterns the MMR has reviewed longline catch data for 2011 and artisanal catches for 2012.
1. What is the difference between the northern and southern fishery waters?
The Cook Islands has an extensive exclusive economic zone where a large range of oceanic conditions affect the abundance and distribution of its fisheries.
The northern sea surface temperatures (SST) are warm and stable almost all year round whereas the SST in the south fluctuates and the temperature gradient between the surface and depths of 150 meters is unstable. The currents flow west driven by the southeast Pacific trade winds and are strongest between April to September. During January to March there is a counter-current in the opposite easterly direction.
In the north there is an upwelling of deep nutrient rich waters known as the “cold tongue” this increases ocean productivity and explains why our northern fishery sustain relatively high catches of albacore tuna and possibly bigeye tuna compared to surrounding ocean waters. The south has low levels of productivity and catch rates are the same or below average compared to the rest of the Pacific with the exception of swordfish.
2. What is the catch and effort for the various fisheries?
In 2011 about 8,400 tonnes of fish was caught between Palmeston and Manihiki by longliners based in Pago Pago or Fiji. There were 75 tonnes caught by the Rarotonga based long liners fishing outside of the territorial seas (12 nautical miles) with most fishing within 100 km radius of the island.
Using artisanal catches for Rarotonga, Aitutaki, Rakahanga and Mangia it is estimated that a total of 290 tonnes is caught within 5 km of the island coastlines. This comprises of 50 tonnes from Rarotonga and Aitutaki, 40 tonnes for rest of the southern group and 200 tonnes caught around the northern atolls.
3. What sorts of species are being caught?
The offshore longliners mainly target the albacore tuna which comprised 57% (4,787 tonnes) of the total catch and mainly unloaded to canneries in Pago Pago (Table 1, Figure 1). Also landed was yellowfin tuna 24% (2,051 tonnes). The bigeye tuna comprised 11% (959 tonnes). Albacore prefer depths of 150 to 200 meters and bigeye tuna are even deeper at 250 to 500 meters. The exploratory fishing which began in 2012 will increase targeted fishing of bigeye tuna.
The Rarotonga longliners catch a wide range of species. In 2011 this included albacore tuna 38% (29 mt), marlin 17% (13 mt), swordfish 13% (10 mt), mahimahi 11% (8 mt) and yellowfin tuna 7% (5 mt).
The coastal species vary according to fishing techniques used such as drop stone fishing in the north or surface trolling in Rarotonga and the south. The dominant species is yellowfin tuna with 81% (234 mt), wahoo 8% (23 mt) followed by marlin, skipjack tuna and mahimahi. These species occupy the shallower depths of the water column, within the top 150 meters.
4. How does the climate affect our fish catches?
Climate plays an important role in distributing fish stocks. The ENSO is an irregular three to seven year oscillation of a warm pool of surface water being concentrated in the west, i.e “El Nino”, or east “La Nina”. Where the warm pool and cold tongue interact is the convergence zone which influences cyclone or drought.
During the strong La Nina of 2011 the Cook Islands experienced changes in fishing patterns compared with 2010. The cold tongue (which caused drought in the north and hypoxia in Manihiki lagoon) significantly expanded the fishing grounds further south.
5. How important are our fisheries and what are some of the challenges?

Fisheries provide food security and livelihoods, supports our traditions and culture and has significant economic potential.
• The coastal fishery is a subsistence activity for most of the sister islands, particularly in the northern and also contributes household income. The catches in Rarotonga and the southern group are much lower than the north and the costs of fuel may result in marginal returns. The game charters are a significant aspect of tourism in Rarotonga and Aitutaki.
• The domestic longliners are an important source of fresh fish to commercial outlets and restaurants on Rarotonga. The local coastal fishery cannot meet the urban demands for fish, especially during periods of the year when catch rates for this fishery are low as fish move further away from the islands. Relocating some of the coastal catch from the north to the south by having fish unloaded or transported to Rarotonga could also address the food security balance.
• The Cook Islands is a resource owner of a large offshore fishery which could potentially significantly increase its GDP. The $40 plus million dollar catch from its EEZ could stimulate international fish trade of up to $200 million dollars. To capture greater benefits to the local economy requires government interventions to modernise the fishing fleets and direct operations towards onshore landing and processing. Challenges to support these activities include the capacity of the port, frequency of sea transport links, the cost of diesel fuel, and the availability of labour.

Herald Issue 608 21 March
- Terms of one China Policy document should be reviewed
- Pacific Media Assistance Scheme Seeks Innovation
- Successful NZ visit by PM
- Rerekura Teaurere New Climate Change Coordinator
- News Briefs