Online Map Of Longline Fishing Activity In Cook Islands Not Accurate

Ministery of Marine Resources 
Rarotonga, Cook Islands

January 5, 2017

The Ministry of Marine Resources (MMR) says a tracking map of longline vessels in Cook Islands waters shared on social media recently is not a true reflection of actual fishing activity.

The image from Global Fishing Watch ( shows the movements of longline fishing vessels in Cook Islands waters over an unspecified time period, but cannot be verified as being isolated to fishing activity, says MMR.

Global Fishing Watch uses public domain data about a vessel’s identity, type, location, speed, direction and more that is broadcast using the Automatic Identification System (AIS) and collected via satellites and terrestrial receivers.

On December 30, New Zealand journalist Michael Field posted an image on Facebook, saying, “People in the Cook Islands wonder why they have no fish left. These are the Chinese longlining tracks for 2016. It does not include the boats in the high seas on either north or south side.”

But Offshore Fisheries Division director Tim Costelloe says the tracks by themselves have little meaning and do not reflect actual fishing activity, only AIS data.

“They do not relate directly to actual fishing days nor the amount caught. Nor does a small scale map such as this accurately represent the narrow tracks of these vessels. The amount of fish caught in 2016 was relatively low. There is significantly more activity on the high seas adjacent to the Cook Islands exclusive economic zone (EEZ).”

Costelloe says the most accurate tracking data for fishing activity comes from the Forum Fisheries Agency (FFA) Vessel Monitoring System (VMS) which allows FFA members to track and monitor fishing activities across the region. Based at the FFA’s regional headquarters, but accessible to all FFA member countries, it is a satellite-based system which monitors the position, speed and direction of registered fishing vessels.

The VMS allows member countries, participating territories and cooperating non-members to monitor fishing vessels in roughly 25 million square nautical miles in the Western and Central Pacific Ocean.

“I can tell you that this map (posted by Field) does not accurately represent anything. I totally respect the work Michael Field did on labour issues in the New Zealand fishing industry which helped to resolve issues we were having with the abuse of foreign crews down there, but he seems to be barking up the wrong tree on this issue,” said Costelloe.

“The number of fishing vessels is capped. There are spatial restrictions in place to minimise interaction with local fishermen.

“We have introduced catch limits through a quota system for longliners and by condition of access for purse seiners.

THERE is no consideration in the models put forward by lobbyists for climatic variations which influence the distribution of highly migratory pelagic species. A single selected and sensationalized picture tells us basically nothing.”

Costelloe says MMR is restricted by regional fisheries management commitments to providing VMS maps to compare to the Global Fishing Watch map. 

“FFA data restriction rules preclude us from sharing operational data compiled by FFA as it is non-public domain data. 

“We are not just the managers we are also the ‘police’ and the data managed by FFA is restricted for use for enforcement purposes.

“This is a policy agreed to by the 17 member nations of the FFA. The picture Michael Field posted has been compiled from AIS data, not VMS data. AIS is for search and rescue and has nothing to do with fishing activity per se.”

MMR has used the same Global Fishing Watch website to provide an image of a four-month period of fishing in and around the Cook Islands in late 2016, to demonstrate how the maps can be used to more closely reflect actual traffic indicating fishing activity.

As a disclaimer, Global Fishing Watch says it analyses AIS data collected from vessels that their research has identified as known or possible commercial fishing vessels, and applies a fishing detection algorithm to determine “apparent fishing activity” based on changes in vessel speed and direction.

“As a result, it is possible that some fishing activity is not identified as such by Global Fishing Watch; conversely, Global Fishing Watch may show apparent fishing activity where fishing is not actually taking place,” says the website.

AIS a maritime navigation safety communications system that provides vessel information, developed for safety/collision-avoidance. 

The regional fisheries management organisation (RFMO), the Western & Central Pacific Fisheries Commission (WCPFC), also maintains a VMS system referred to as the Pacific VMS and requires all fishing vessels to be fitted with an Automatic location communicator (ALC) –  a near real-time satellite position fixing transmitter, under a Conservation and Management Measure (CMM) adopted in 2006.

Costelloe says the image of four months of fishing activity from Global Fishing Watch clearly shows that the Cook Islands has well-managed fisheries.

“Compared to the level of activity seen beyond the Cook Islands EEZ, the image demonstrates our commitment to best practice fisheries management, in the face of intense fishing pressure in areas beyond our national jurisdiction,” says Costelloe.

“At today’s date (January 4) there are only four commercial vessels fishing in our EEZ, two purse seiners (US) in the north and two local vessels fishing out of Rarotonga.”

To find more information on offshore fisheries, follow MMR on Facebook at or go to its website at


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