Closing the High Seas: Potential Implications and Outcomes

Part III of IV

By Gretchen Thuesen


Closing the high seas to fishing has been a contentious and debated topic in international fisheries news and policy. Two recent papers suggest major benefits from closing the high seas. A 2014 paper by White and Costello claimed that closing the high seas (HS) to fishing entirely would allow for >100% increase in fisheries profit, >30% increase in fisheries yields, and >150% increase in fish stock conservation. In short, it would return “larger fishery and conservation outcomes than does a HS open to fishing.” Another paper by Sumaila et al. 2015 examined potential changes in global catch as a result of closing the HS and found that “closing the HS could be catch-neutral while inequality in the distribution of fisheries benefits among the world’s maritime countries could be reduced by 50%.”

We collected responses (originally in an email chain) from an array of experts on aspects of closing high seas fisheries then summarized their main points into four commentaries:

  1. Should we close the high seas to fishing?
  2. Motivations for closing the high seas
  3. Closing the high seas – potential implications and outcomes
  4. Alternatives to closing the high seas – other potential strategies and outcomes

Closing The High Seas – Potential Implications and Outcomes

Respondents discussed implications and potential outcomes of closing the high seas, and presented hypothetical situations according to their individual experience and expertise in fisheries management. Outcomes discussed were organized according to: (1) The effectiveness of management in the HS v. in the EEZs and the potential of fishing effort spillover, and; (2) Other potential ecological and management impacts.

The effectiveness of management in the HS vs. in the EEZs and the potential of fishing effort spillover

“Whether this [closing the high seas] is even worth discussing depends critically on how failed the institutions are on the HS,” says Chris Costello. “White and Costello modeled a range of scenarios for this from “perfect institutions” (in which case a HS closure makes no sense from a fishery perspective) to complete open access with many countries (in which case it does because the game theoretical outcome is to overfish significantly). I don’t know of any systematic empirical analysis of how “failed” the institutions are on the HS. My sense is that HS institutions are not great, but are probably better than they were 10 years ago.”

“Another key factor is how good the institutions are in EEZs,” Chris Costello continues. “If EEZs are not equipped to properly manage catch in a responsible manner, then this could also undermine any benefits of a HS closure.” “The concern of effort spillover hinges on institutions within EEZs,” says Costello.

Ernesto Penas-Lado holds a different view. “Like in all area-based measures, it is taken for granted that fishing pressure will be reduced, instead of simply changing area,” he says. “If HS fishing is banned, my experience tells me that many vessels would seek access to EEZs, either legally (through agreements with Coastal States) or illegally (IUU). Overall this can produce an aggravation of the overfishing already taking place in a number of EEZs around the world. The allegation by White and Costello that the measure would “reduce overall exploitation rates” is unfounded. In fact, following the declaration of 200-mile EEZs in many countries around the world, the overall fishing effort increased, not diminished, as a result, due largely to an increase in fishing pressure by the Coastal States.”

“The idea seems to be based to some extent on the belief that HS fisheries are not well managed while those in EEZs are,” Penas-Lado continues. “Again, my long experience tells me this is too often not the case at all. White & Costello say that HS fisheries are “essentially open access”. That is not true. Many of the fisheries in the HS are in fact managed, and some even very well managed. Examples are NAFO in the NW Atlantic (excellent management including enforcement), some ICCAT fisheries, the IATTC, etc. are well managed fisheries, including good enforcement. In contrast, many management systems by Coastal States within their EEZs are a complete disaster, without serious science or enforcement and with management riddled with IUU and corruption. Some countries in West Africa are the best examples.”

“The spillover effect is less than obvious to me,” says Penas-Lado. “While Sumaila et al propose a figure of a substantial 18% (not clear to me, this would need careful examination of the hypothesis, the article does not clarify all), White & Costello projections are way too optimistic and are not well founded in my view. This is certainly something that needs more careful analysis.”

Closing the HS “eliminates the RFMOs that manage the fisheries on the high seas but also with respect to harvests in national EEZs,” says Dave Fluharty. “These mechanisms are not perfect by any means but without international RFMO management the tuna ecosystem is ignored and the complications of agreement by individual states are exacerbated.” “Those proposing closure need to identify the problems with international agreements for managing highly migratory species and propose solutions for them one of which can be closure but that approach must be compared against other measures. We are talking about a very specific set of international fisheries,” Fluharty continues. “Especially with pelagic fisheries the regime must take into account variability in stock size, temporal and spatial distribution, catchability, transfer and processing and incidence of social and economic impacts.”

Other potential ecological and management impacts

Closing the HS may:

  1. Impact migratory stocks.
    • “For species that migrate along several EEZs (salmon, mahi mahi) the interception issues will become worse with more effort in the EEZs,” says Martin Hall. It is important to note that this particular concern refers specifically to migrations along EEZs, “and the interception issues willworsen if all the harvest is concentrated there. This is not dependent on the ecology, habitat use, etc. of a species,” says Dr. Hall. That said, there are additional considerations to be made in other geographical cases which may complicate resource management, allocation, etc. For instance, “different tuna billfish and shark populations use specific EEZ areas (seasonally),” says John Musick. “That use may be all out of proportion to total area of that country’s EEZ. The geographic Devil is in the details, and should be approached on a population basis.”
  2. Increase negative interactions and competition with artisanal and recreational fishing concentrated in the EEZs, thereby also increasing fishing mortality in the EEZs.
  3. Intensify sea turtle, marine mammal, and seabird conservation problems already present in EEZs by increasing bycatch of these animals due to higher overall effort.
  4. Increase catches of juvenile species (e.g. bluefin and yellowfin tunas, salmon, herring, hammerhead sharks) that reside in the EEZs.
  5. Increase interactions with oil and gas exploration and exploitation operations, which are predominantly EEZ-based.
  6. Increase conflict between economic sectors (shipping, in particular) as fishing becomes more concentrated in the EEZs.
  7. Eliminate resource access for some countries, particularly those without EEZs or with small EEZs, which would aggravate resource competition among countries.
    • This would “increase conflict, not cooperation,” says Ernesto Penas-Lado. Further, closing the HS “would increase the mismatch between countries with technology to fish and markets for the fish and those with neither. One can argue this could be good in terms of social/political equity, if this results in gains for developing countries, but then, if we believe Sumaila et al. (I have plenty of doubts about that analysis) the winners are USA, Guam (USA) and UK. Hardly developing countries,” says Ernesto Penas-Lado. “This measure would change the winners and losers.”
  8. Raise questions regarding the future food production (that will have to increase with increasing human population).
    • “The high seas are apparently the only areas where substantial increase in “fish” production is still possible,” says Petri Suuronen. “One potentially large source is mesopelagic fish species. These fish consists of a group of species living mainly in the depths of around 250 ‐ 1200 meters in the oceans. Although there is large uncertainty regarding quantity of this resource and how it could be exploited cost-effectively, it is probably the largest global fish resource yet not utilized and it thus represents a large reserve for increased supply of protein and fat from the ocean. Furthermore, there are also large quantities of zooplankton, including krill and copepods, that represent a potentially large source of food.” Finally, “closure promotes inefficiency in harvest of valuable resources and a great source of food with only limited alternatives – each of which having tradeoffs,” says Dave Fluharty.

Read the rest of the series:

Featured in the discussion:

Martin Hall

Head of Bycatch Programs and Agreement for the International Dolphin Conservation Program of the Inter-American Tropical Tuna Commission (IATTC) since 1984.

Sidney Holt

Author of “On the Dynamics of Exploited Fish Populations” published in 1957; Served with the FAO in 1953 and with other UN agencies for another 25 years.

George Rose

Retired; Former Head of the Fisheries Conservation Group and Director of the Centre for Fisheries Ecosystems Research (CFER); Worked in the Newfoundland and Labrador fisheries for almost 30 years.

John Hampton

Oceanic Fisheries Program (OFP) Manager at The Pacific Community (SPC); Has 30 years of experience in tuna stock assessment, and currently works on the development and application of the MULTIFAN-CL stock assessment model.

John Sibert

Program Manager of the Pelagic Fisheries Research Program (PFRP), in the Joint Institute of Marine Research of the University of Hawaii at Manoa; 40 years of experience in marine science research, most of it involving quantitative analysis of complex systems using non-linear statistical models.

Chris Costello

Professor of Natural Resource Economics, Bren School UCSB; Research Associate, National Bureau of Economic Research

Ernesto Penas-Lado

Director for Policy Development and Coordination at the European Commission’s Directorate-General for Maritime Affairs and Fisheries since 2010; He first joined the European Commission in 1986.

Alfred "Bubba" Cook

Western and Central Pacific Tuna Programme Manager for WWF’s Smart Fishing Initiative; 13 years of experience working in fisheries conservation and management.

John Musick

Faculty Emeritus at Virginia Institute of Marine Science (VIMS).

Petri Suuronen

Fisheries Expert in the FAO Fisheries and Aquaculture Department, Fishing Operations and Technology Branch (FIAO) since 2009; Former Research Director at Finnish Game and Fisheries Research Institute for 12 years.

Dave Fluharty

Associate Professor at the University of Washington School of Marine and Environmental Affairs since 2000; Chaired / Sat on numerous boards and committees for, among others, NOAA and the North Pacific Fisheries Management Council and consulted on projects from West Africa to the Yellow Sea.