ENSO and Society Island Tuna Fisheries

Looking at the Pacific Ocean on a large scale, you may just see endless blue waters. Zoom in and what you find is an array of beautiful islands with fascinating cultures. Fishing has been part of the Polynesian culture for centuries, starting as an individual activity to provide food for oneself or one’s family. This was done by different techniques like spear, line, or nets.[1] As years passed, fishing became an important part of French Polynesia’s economy, and techniques and boats evolved to keep pace with the increasing demand of the market. Today, more than 6,500 tons of tuna are caught per year. The effects of climate change and climatic phenomena such as El Niño Southern Oscillation (ENSO) on tuna populations can have a great impact on the fragile economies of French Polynesia, which harvests approximately 25.5 million USD in tuna stocks each year due to their vast Exclusive Economic Zone (EEZ) consisting of 4,200,000 km2 of some of the richest fishing grounds in the world.[2]

El Niño Southern Oscillation (ENSO)

Under normal atmospheric conditions in the Pacific basin, there is a high pressure system over the western coast of the Americas, which is typically associated with arid conditions, and a low pressure system over southeastern Asia, which is typically associated with humid, rainy conditions (Figure 1a).[3] The pressure works in tandem with westerly trade winds to force the surface water westward along the equator until it bumps into a landmass and is forced downward. Ultimately this water must go somewhere, so a combination of atmospheric and oceanic forces creates a current that runs East deeper in the ocean than the surface current going the other direction. Reality is never as tidy as our models, and these conditions are not always stable from year to year. A climatic trend known as El Niño Southern Oscillation (ENSO) occurs, on average, every four to seven years, and has a strong effect on this cycle.[4] This is of particular interest to the fishermen of French Polynesia, on whom many communities depend.

During what is called an El Niño event, the pressure systems on either end of the Pacific basin weaken, or even switch so that there is high pressure over southeast Asia and low pressure over the western coast of the Americas, and the trade winds blowing from East to West across the Pacific weaken.[5] The effects are global [6] but its effects on French Polynesia will be the focus here.

Temperature changes also occur across the Pacific Ocean basin as a result of an El Niño event. The surface of the equatorial Pacific becomes warmer than normal because of decreased upwelling (Figure 1b).[7] This is characterized by an eastward shift of the Western Pacific Warm Pool (WPWP).[8] The other type of temperature change is called La Niña (essentially the opposite of an El Nino event), when the surface of the Pacific becomes colder than normal (Figure 1c). This is characterized by the WPWP being more confined to the western edge of the Pacific basin.[9] This temperature shift is the focus of our research since it is the ecological driver of the change we see in fish behavior. Thus, it is the more important aspect when trying to discern the effects ENSO has on the fisheries of French Polynesia. That being said, it is important to understand that the temperature changes and pressure changes that occur are part of the same system (ENSO) and thus happen concurrently.[10]


Figure 1. a) Surface temperature (red=warm, blue=cool), net water movement (noted by arrows), and atmospheric convection in the equatorial Pacific in normal conditions. b) Surface temperature, net water movement, and atmospheric convection during an El Niño event. c) Surface temperature, net water movement, and atmospheric convection during a La Niña event.[11]

El Niño affects various fisheries throughout the Pacific,[12] but the focus here is on the effects seen around the French Polynesian islands of Tahiti, Rangiroa, and Nuku Hiva. We looked at various species of tuna since they comprise a significant majority of the commercial fisheries in this area: In 2002, Albacore comprised 43% of the total catch from French Polynesia, Yellowfin comprised 13%, and Skipjack comprised 12% of the catch.[13] This is important because the effects El Niño has on the tuna fishery in this area could have repercussions for the economies of French Polynesia and for the lives of the individual fishermen as well.

Evidence suggests that in the western and central Pacific, the majority of surface Skipjack and Yellowfin tuna shift eastward during El Niño events. This is based on the eastward displacement of the warm pools of the Pacific and the corresponding geographic shift in Tuna populations. Under normal conditions the tuna concentrate west of the 160 West line of longitude. During El Niño events there is a noticeable shift eastward of this line.[14] According to a study done by University of Hawai’i, Skipjack recruitment is higher after an El Niño event due to the warmer surface temperatures. However, if followed by a strong La Niña the recruitment is negatively impacted.[15]

 

Tuna Ecology

The Western Pacific Ocean provides 40% of the world’s total tuna catch every year (>1.5 million tons year−1), despite its low primary productivity.[16] The majority of the total tuna catch is dominated by two tropical species, Skipjack (Katsuwonus pelamis) and Yellowfin (Thunnus albacares). These species are found in the surface mixed layer of the Pacific waters, and are top predators in Pacific pelagic ecosystems.[17] Tuna are very active fish that have to swim great distances at great speeds to counterbalance their negative buoyancy. Tuna need to recover energy spent in traveling by constantly feeding.[18] Tuna have to consume approximately 15% of their body weight per day to sustain their high metabolism.[19] This is one of the reasons that caused tuna to become such a flexible and opportunistic predator. Tuna also have a very high growth rate and are short-lived, which makes them suitable for big fisheries and capable of sustaining the economies of French Polynesia.

Tuna inhabit the warm pool of the Pacific Ocean, in temperatures that range from 20 to 30 degrees Celsius. Their distribution is determined by ambient temperatures as well as dissolved oxygen levels and water clarity. Water clarity is essential because tuna hunt mainly by vision.[20] Tuna, especially in early stages of their life, depend on warm water temperatures to develop successfully. Egg and larval malformations occur when water temperatures are too cool- less than 20 degrees Celsius.[21]

During El Niño events, the extent of the warm pools across the equator changes, and a corresponding change in the distribution of tuna occurs.[22] El Niño causes the barrier layer between the cold tongue and the warm pools to shift eastward,[23] causing warm waters to extend to the central Pacific region and causing changes in the upwelling currents and a decrease in primary production.[24]

 

Fisheries in French Polynesia

The Society Islands are heavily dependent on the success of their fisheries for both economic and cultural reasons. The fisheries have changed over time, but fishing has always been a strong part of French Polynesian culture. Before the 1990s, near shore commercial fishing vessels were quite common, often 12m in length or smaller, employing methods of line and pole fishing or trolling. Foreign vessels were also present, using longlining methods further offshore than local boats would venture, fishing on licenses sold by the French Polynesian governments. However, in the 1990s, the French Polynesian governments decided to introduce longlining fishing methods with a drifting monofilament in order to make better use of their national open water fisheries resource. By the end of the 1990s, longlining was a successful and rapidly increasing practice in French Polynesian fisheries.[25] French Polynesian fisheries are today largely monitored and managed by the Secretariat of the Pacific Community Oceanic Fisheries Program (SPC OFP). The SPC is an international organization that has worked with tuna stock assessments, ecosystem research, and fishing policies since the 1980s, as well as running many other development programs.[26]

It may thus be surprising that in 2014, there were reports of longlining fishing fleets are having difficulty “maintaining profitability,” although stock assessments “continue to produce relatively healthy results.” The Pacific Islands Tuna Industry Association (PITIA) reported in February 2014 that the Fijian longlining fleet in particular was using only half of its fleet capacity at that time.[27] However, the reasons behind this change from dramatic growth in the longlining industry to a sudden drop in active fishing are more complicated than a simple lack of fish. In order to understand why a vessel might stay tied up when there are still fish available according to the stock assessments, one must consider the work it takes to catch what’s available. Right now, the catch per unit effort (CPUE; a term used to refer to how beneficial a catch really is given effort expended) is relatively low.[28]

Longlining involves the physically demanding effort of laying kilometers of baited hooks[29] that tend to target the physically larger tuna. This specific size targeting on the part of the fishermen means that this portion of the tuna population is in rapid decline, and perhaps will become a less common trait in the future. For this reason, the types of fish that fishermen target are not doing well enough to yield high catch rates. However, the smaller and younger fish are able to continue to mature and spawn, meaning that the population is often reaching a successful reproductive age before they are caught, and so the population could be considered to be doing quite well, as the stock assessments have claimed.[30]

The tuna fisheries, in this way, are more sustainable than many fisheries which catch fish before they reach reproductive age. The SPC OFP considers that this may be a part of the reason that stock assessments have claimed that the albacore populations are at healthy levels, while many of the tuna fishermen are claiming otherwise and staying in due to a low CPUE (although the SPC noted that many other factors, such as fuel and fish prices also influence the CPUE, and could have an unaccounted-for effect).[31] Another stock assessment is expected to be completed in 2015, though SPC OFP suggests that bio-economic modeling (models taking into account the costs of fishing and fish price) would be a more accurate assessment of the true condition of the fisheries, and that the results would likely be “far less rosy than the biological [results].”[32]

This gets at a pertinent point in fisheries management strategies, only recently beginning to be acknowledged: the sociological and economic variables involved in a healthy fisheries ecosystem. The “fundamental blind spot of fisheries policy and management” is based in the fact that “although the objectives are to achieve the long-term health and viability of fisheries, the prescription is to protect marine ecosystems with no words or thoughts to the dynamics of fishing fleets, including their economics and behavior.”[33]


Figure 2. SEAPODYM model of expected changes in location of various tuna populations.[34]

It is, in fact, a combination of efforts to monitor the biological, sociological, and environmental factors that will be truly necessary to manage French Polynesian fisheries. This is where climate change becomes important to this discussion. The SPC’s OFP has a history of monitoring the impacts of environmental changes associated with ENSO on tuna fisheries, and as climate change becomes a pressing environmental factor, they are also moving to model the expected future effects of climate change. Their complex model, called SEAPODYM, is in the process of being used to synthesize historical atmospheric CO2 data starting as early as 1860 in order to understand larger time-scale trends. It is also investigating various scenarios from the Intergovernmental Panel on Climate Change (IPCC), outlining atmospheric and oceanic CO2 levels over time (also a scenario involving sociological variability) and how that may affect Pacific tuna populations.[35]

The first phase of the climate change investigation, which began in 2011, was a preliminary investigation into the effects of climate change on four main species: Skipjack, Bigeye, Yellowfin and Albacore tuna. Previous SPC modeling of ENSO effects on these populations revealed that albacore populations tended to do worse and diminish during El Niño years, but that the other three species might do better.[36]

For climate change, these changes by species were partially true, though the changes they claim that we will see are going to be in many ways different than the types of climate variations seen in recent history as with events like El Niño and La Niña. According to the SRES A2 IPCC scenario of CO2 levels, the SPC OFP found a strong trend in their models of Skipjack and, most particularly, Bigeye tuna migrating eastward. They believe that this would be largely due to reduced equatorial upwelling (upward currents carrying nutrients to the surface to feed the base of the whole food chain).[37]

The second phase of the SPC OFP climate and tuna investigation is focused on the uncertainty in the earlier predictions, and a more comprehensive look at the changes in populations. At the time of this writing, they were still investigating possible funding sources, and the phase had not yet been carried out.[38]

Once the expected changes in tuna populations are more fully understood, however, the challenge will be how to move forward with fisheries management in a manner that agrees with the fishermen involved that will simultaneously be effective in maintaining healthy fish ecosystems. One must consider in fisheries management how the fishermen will react to proposed limitations, and how they may choose to expand into other methods of fishing to compensate for their lost freedom and economic gain from the original species, location, or vessel specification. A balance must be struck between policies that agree with the fishermen and that also protect the fish; this balance will be known when the stock assessments and the fishermen both give positive reviews of the current fisheries, while complex models such as SEAPODYM agree that it is a healthy ecosystem.

The SPC has begun this community outreach effort in part by creating a tuna-tagging project separate from climate models whose purpose is to monitor the size range, age, mortality, fishing mortality, and migrations or movements of tuna populations. Environmental parameters are being measured with the help of satellite and electronic tags to monitor behavior with specific environmental changes. A key part of the project, though, is to get the community involved in order to gain community support. They have created a system with rewards for the return of tags and a strong media involvement. Posters outlining information to collect and who to contact were produced in 13 languages and posted near key tuna locales throughout the regions of Pacific and East Asia. Additionally, Tag Recovery Officers are placed in key locations and strongly supported by SPC.[39]

If fishing limits are to be imposed in Pacific Islands, particularly in French Polynesia, a final important consideration would be who will be enforcing such a restriction. In French Polynesia, any vessel has to be granted permission to fish in waters within their EEZ, or the 200 nautical mile radius around a country’s coast whose fishing rights belong exclusively to that country. That fishing permission depends on the national fishing agreement that is held by the fisheries department. Moreover, the French army is in charge of monitoring French Polynesia’s EEZ to ensure there is no illegal fishing activity.[40]

 

Field Observations in French Polynesia

Papee’te, Tahiti (March 24, 2014)

In Papeete, Tahiti, our group had the chance to talk to a few local fishermen, who gave us an overview of the inner workings of the offshore fisheries. Tiaehau Ere’dèrie, Captain of an offshore fishing vessel for more than 20 years, talked to us about tuna and the fishing process from beginning to end. In Papee’te they use the longline fishing method to catch tuna. They generally end up catching about 100 tuna (Albacore, Bigeye and Yellowfin) per trip. He mentioned other fish they caught, including Marlin, Mahi mahi, Salmon, and Meka. He also showed us the data sheet that they keep on board, which includes information from the beginning until the end when they bring back the lines. This includes: Position (Latitude and Longitude in which they set up the fishing lines), speed (in knots), time, species caught, weight, and number. They also record all of the bycatch and its state, which according to the captain is very low and most of the times get returned to the ocean alive.

The Captain explained that they can go very far sometimes to fish and that they do not really have a place where they concurrently go back to; instead they follow the fish as able and depend on other fishermen’s observations. They go almost as far as the Marquesas but not further, which means that they can’t follow tuna migrations as far as they would have to during El Niño years.

The fisheries in Papeete, from our observations, seem to be very well managed and seemed to have a good relationship with the administration. Tiaehau also mentioned that the government closed the doors to foreign vessels in order to “keep the local fisherman happy” since having foreign vessels negatively affected local catch.

We had the fortunate opportunity to speak with members of the OFP SPC’s Observer Programme as well while we were in Papeete. During this meeting, they emphasized several times that there are not in fact many changes in fish from year to year in terms of species, size, or distribution. However, they did point out that there are other cycles of change not as clear cut as those of El Niño or La Niña. One of these cycles is a cycle that takes place approximately every ten years and may be linked to ENSO, but doesn’t align perfectly with three to five year cycle. They said that though there is no index to measure such a change, it becomes clear during these times that the larger Tuna have migrated towards the Marquesas Islands. The OFP Observers believe that the cycle comes in two parts, and that the second part was due soon at the time of this writing. The cycle, they said, is defined by catch yield more than any other characteristic and is known well by fishermen but not understood well by scientists. This led us to ask about the information pathways from fishermen up to policymakers, and they said that they were quite limited. Family connections to fishermen within the SPC OFP were one of the few direct connections in their department, though relations between the SPC OFP and fishermen were generally very positive.

As the observer programme, the OFP office said that they are able to investigate more than 90% of what is unloaded from fishing vessels in Papeete harbor, the only large fishing port in Tahiti. The harbor brings in 5-7,000 metric tonnes per year, much of which is Albacore tuna. There are sixty longliners based out of the harbor. Additionally, the observer programme is able to examine 8.8% of the longlining hooks that are deployed, giving them a good handle on the current state of fisheries from the perspective of counting and inspections of fish and equipment.

They wanted to clarify that Fiji has had a harder time than Tahiti lately in the longlining industry, largely due to overfishing. French Polynesia closed its doors to foreign fishing vessels largely for this reason in 2000, and so has been able to maintain a healthier tuna industry than that which is seen in Fiji.

Rangiroa

The next port was Rangiroa, where Hurupa, a local fisherman, explained that the local fisheries use buoys to fish for the tuna. They generally let out 200-400m of line at the surface and fish down to a depth of 80-100m. He mentioned that the tuna like temperatures ranging from 26-27 degrees Celsius, and he indicated that there was not a noticeable change in the amount of tuna that he and the other fishermen had observed or the price for tuna.

Nuku Hiva

While in Nuku Hiva, we had the opportunity to speak with local fishermen and government officials. Some of the local fishermen stated that there were not as many fish during El Niño, and that the fish that are there go deeper, from their normal depth of around 18m to around 150m. They also explained that the local fishermen do not have any restrictions on their catch, whereas the Chinese boats that fish in their waters do. They apparently sell the fish locally, not bothering to export any of it. Towards the end of the interview, one of the fishermen added that the government makes laws without consulting them. A fisherman who was not informed about El Niño explained that there were times when the water became murky and the fish left. This corresponds with what Teiki, the second adjunct to the mayor of Nuku Hiva, told us. Teiki spoke of the same phenomena, stating with confidence that it corresponded with El Niño.

 

Conclusions

After analyzing literature on the subject and speaking with local fishermen and government officials, a few things are clear. First, there needs to be more communication between the fishing industry and policy makers not only of Tahiti, but also between the fisheries and governments on the rest of the islands. A collaboration between these two parties is the only way to ensure a seamless fisheries management, something that is essential for the islands of French Polynesia that rely on these industries. Also, fisheries management and policy makers in French Polynesia should account for all of the different types of fisheries, because as we observed, they vary from island to island.

One of the things noted is that during El Niño years fisheries do see changes in their catch. Although science may suggest that some of the tuna species do better during El Niño years, they do not take into account the tuna migration. These large migrations make tuna inaccessible to Polynesian fishermen who have to settle for other species during those years.

Another point to note is the lack of strategies to ameliorate the catches of El Niño years since there is not a lot of information concerning how far the tuna go and how feasible it is for the fishermen to go after them. This also signifies an extra investment of both time and resources.

Climatic events such as El Niño and La Niña are unpredictable and the magnitude of the damage cannot be measured appropriately; despite the fact that French Polynesian fisheries have low catch during these events, they are very well structured. The relationship between fishermen and the management seems to be a good one, and we found that the offshore fisheries in Papeete were very aware of El Niño and what it meant for them. Smaller fisheries like the ones in Rangiroa and Nuku Hiva were less prepared to face these events but are more flexible to changes since they sell their product locally and in a smaller scale.

 

Tuna Field Research Photo Journal


Figure 3:
In this picture we see one of the many tuna caught by local fisherman being processed in a warehouse at the fishing dock in Pape’ete, Tahiti. A worker skillfully makes the first cut in the back of the tuna.


Figure 4:
This is the fishing vessel we were given a tour of, the Tauraa Tua IV, in Pape’ete. Notice the fresh paint job, a sign of prosperous fishing activity. Fishermen coordinate the processing of their most recent catch.


Figure 5:
A local fisherman in Pape’ete held up one of his newly caught fish for us minutes before processing it on board. In the background you see Tauraa Tua IV among the rest of the fleet.


Figure 6:
These are the drums that are used to deploy the longlines in Pape’ete, also found on the Tauraa Tua IV. This is a good indication of the scale of the fishery.


Figure 7:
A local fisherman in Nuku Hiva cleans that morning’s tuna catch, preparing it for sale at the local market. He sold some of the fish from the table before the sun had risen.


Figure 8:
A local market in Pape’ete. You can clearly see the various vendors selling fish, much of which was tuna. This shows the importance of Le marché municipal to Tahitians and represents the economic role fisheries play in French Polynesia.


Figure 9:
Longlines ready for the next trip. These were located on the fishing vessel Tauraa Tua IV in Pape’ete.


Figure 10:
An El Niño chart we saw in the Secretariat of the Pacific Community Oceanic Fisheries Program (SPC OFP) office in Pape’ete where we interviewed the coordinator of the observer program.


Figure 11:
A close up of the preparation of tuna fillets in Pape’ete.

 

Alessandra de la Torre, Boston University
Alia Payne, Macalester College
Jackie Kroeger, University of North Carolina Wilmington
2014

 

References

[1]   Encyclopedia Britannica. Polynesian Culture: Production and Technology. Accessed 09 Mar, 2014. http://www.britannica.com/EBchecked/topic/468832/Polynesian-culture/276579/Production-and-technology

[2]  Secretariat of the Pacific Community. Accessed Mar 09, 2014. French Polynesia Assessment. http://www.spc.int/climate-change/fisheries/assessment/chapters/summary/6-fr-polynesia.pdf

[3]  Kao, H.-Y., and Yu, J.-Y. 2009. Contrasting Eastern-Pacific and Central-Pacific types of ENSO. Department of Earth System Science. University of California Irvine. Journal of Climate. 22: 615-632.

[4]  Kao and Yu, 2009

[5]  McPhaden, M.J. 1993. TOGA-TAO and the 1991-93 El Niño-Southern Oscillation event. Oceanography. 6: 36-44.

[6]  Cai, W., S. Borlace, M. Lengaigne, P. van Rensch, M. Collins, G. Vecchi, A. Timmermann, A. Santoso, M. J. McPhaden, L. Wu, M. England, E. Guilyardi, and F.-F. Jin. 2014. Increasing frequency of extreme El Niño events due to greenhouse warming. Nature Climate Change. 4: 111–116.

[7]  Cai et al., 2014

[8]  Bell, J.D., Adams, T.J., Johnson, J.E., Hobday, A.J, and Gupta, A.S. 2011. Secretariat of the Pacific Community: Vulnerability of Tropical Fisheries and Aquaculture to Climate Change. Secretariat of the Pacific Community, Noumea, New Caledonia Ch. 1:  346

[9]  Bell et al., 2011

[10]  Kao and Yu, 2009

[11]  National Oceanic and Atmospheric Administration: El Nino Theme Page. Accessed 09 March 2014.  http://www.pmel.noaa.gov/tao/elnino/nino_normal.html#top

[12]  National Oceanic and Atmospheric Administration. National Marine Fisheries Service. 2014. http://www.elnino.noaa.gov/enso4.html

[13]  Hamnett, M.P. and C. L. Anderson. 2000. Impact of ENSO Events on Tuna Fisheries in the U.S. Affiliated Pacific Islands. Honolulu: Social Science Research Institute, University of Hawaii. http://www.soest.hawaii.edu/pfrp/soest_jimar_rpts/hamnett_enso00.pdf

[14]  Dalzell, P., Adams, T.J., and Polunin, N.V. 1996. Coastal Fisheries in the Pacific Islands. Oceanography and Marine Biology: An Annual Review. 34: 395-531.

[15]  Hamnett and Anderson, 2000

[16]  Lehodey, P. 2001.The Pelagic Ecosystem of the Tropical Pacific Ocean: Dynamic Spatial Modelling and Biological Consequences of ENSO. Progress in Oceanography. 49 (1–4) 439-68.

[17]  Lehodey, 2001

[18]  Lehodey, 2001

[19]  Miller, K.A. 2007. Climate Variability and Tropical Tuna: Management Challenges for Highly Migratory Fish Stocks. Marine Policy. 31.1: 56-70.

[20]  Brill, R.W. 1994. A review of temperature and oxygen tolerance studies of tunas pertinent to fisheries oceanography, movement models and stock assessment. Fisheries Oceanography. 3: 204–216.

[21]  Wexler, J.B., D. Margulies, and V. P. Scholey 2011. Temperature and Dissolved Oxygen Requirements for Survival of Yellowfin Tuna, Thunnus albacares, Larvae. Journal of Experimental Marine Biology and Ecology. 404 (1–2) 63-72.

[22]  MacPhaden M.J. and J. Picaut. 1990. El Niño–Southern Oscillation Index displacements of the Western Equatorial Pacific warm pool. Science. 50: 1385–1388.

[23]  Vialard J. and P. Delecluse. 1998. An OGCM study for the TOGA decade. Part I: role of salinity in the physics of the western Pacific fresh pool. Journal of Physical Oceanography. 28: 1071–1088.

[24]  Lehodey, 2001

[25]  Misselis, C. 2002. "French Polynesia Tuna Fisheries." SOEST. Service De La Pêche,. Accessed 09 Mar. 2014.

[26]  Secretariat of the Pacific Communities Oceanic Fisheries Programme. 2010. "The Oceanic Fisheries Programme." Secretariat of the Pacific Communities. Accessed 10 Mar. 2014.

[27]  Pacific Islands Tuna Industry Association (PITIA) 2014 "View from the Industry -." Island Business. Accessed 09 Mar. 2014.

[28]  Misselis, 2014.

[29]  Secretariat of the Pacific Communities Oceanic Fisheries Programme. 2014. "A Scientific Perspective on Current Challenges for PICT Domestic Tuna Longline Fleets That Are Dependent on South Pacific Albacore." Accessed 09 Mar. 2014.

[30]  "A Scientific Perspective on Current Challenges for PICT Domestic Tuna Longline Fleets That Are Dependent on South Pacific Albacore", 2014

[31]  "A Scientific Perspective on Current Challenges for PICT Domestic Tuna Longline Fleets That Are Dependent on South Pacific Albacore", 2014

[32]  "A Scientific Perspective on Current Challenges for PICT Domestic Tuna Longline Fleets That Are Dependent on South Pacific Albacore", 2014

[33]  "A Scientific Perspective on Current Challenges for PICT Domestic Tuna Longline Fleets That Are Dependent on South Pacific Albacore", 2014

[34]  Branch, T.A., et al. 2006. "Fleet dynamics and fishermen behavior: lessons for fisheries managers." Canadian Journal of Fisheries and Aquatic Sciences 63.7: 1647-1668.

[35]  Secretariat of the Pacific Communities. 2014. "Modelling the Effects of Climate Change." Accessed 09 Mar 2014.

[36]  Secretariat of the Pacific Communities. "Modelling the Effects of Climate Change.", 2014

[37]  Secretariat of the Pacific Communities Oceanic Fisheries Programme. 2010. "Historical Work." Accessed 09 Mar. 2014.

[38]  Secretariat of the Pacific Communities. 2014. "Project Purpose." Accessed 09 Mar. 2014.

[39]  Secretariat of the Pacific Communities. 2010. "Pacific Tuna Tagging - About Tagging." Pacific Tuna Tagging. Accessed 10 Mar. 2014.

[40]  Western & Central Pacific Fisheries Commission (WCPFC). 2005. "Commission for the Conservation and Management of Highly Migratory Fish Stocks in the Western and Central Pacific Ocean First Meeting of the Technical Compliance Committee." Accessed 09 Mar. 2014.

 

How to cite this entry:
Alessandra de la Torre, Alia Payne and Jackie Kroeger. 2014. "ENSO and Society Island Tuna Fisheries." Atlas on Sustainability of Polynesian Island Cultures and Ecosystems. Sea Education Association, Woods Hole, MA. Web. [Date Accessed] <html>