There was a lot discussions a few months ago in terms of the closure of the Phoenix Islands Protected Area (PIPA) in Kiribati… with far-flung accusations being made against the iKiribati people and China bashing since Kiribati recently re-established diplomatic with them… and (of course!) they must have something to do with it.
The WCPO showing the EEZ of coastal States (light blue), PIPA (yellow) and the three large oceanic MPAs evaluated in the study.
I feel that there is a lot of “amateurism” around MPAs as “magic bullets”. As with most things in fisheries, their utility varies depending on many things… i.e. their utility will be vastly different from a coral reef with demersal species to an open chunk of ocean with pelagic ones. Furthermore, I’m a strong believer that to fix a problem; you need a toolbox, not just a hammer… (when you only have a hammer, all problems look like nails?)
Furthermore, I had a long-standing beef with MPAs and other conservation measures mostly promoted (and sometimes imposed) by developed countries on people from developing states as blanket statements (30 by 30), where in most cases, locals are only involved in a tokenistic way.
So, I was really interested to see this paper appearing on my radar: “Limited conservation efficacy of large-scale marine protected areas for Pacific skipjack and bigeye tunas” Particularly because I know and immensely respect 3 of the authors, John Hampton and Simon Nicol, both are top scientists at SPC and know the pacific very well (I know about joe, Patrick and Inna but never met them) But crucially I’m verty pleased to see my friend and colleague Kaon Tiamere that is the Acting Director of the Licensing and Compliance Division at the Kiribati MFMRD.
They did not only dig deep into PIPA data but also analysed the likely tuna conservation efficacy of several much larger hypothetical MPAs, each constituting around 33% of the WCPO ocean area. While these larger areas may have a slightly greater impact on tuna stock conservation than the PIPA, and may also be targeted at a much broader range of conservation outcomes, the study concluded that they were unlikely to be effective frontline fisheries management tools for tropical tuna
This paper is crucial reading (in my humble opinion) for those pushing for massive MAPs for pelagic regions, so please read the original
Before I dive into the paper, I like to quote the words of my 3 friends on the SPC release on this paper. Crucial are Kaon’s words as a good antidote to the “white saviourism” of many in the rich environmental NGO world... “Kiribati MFMRD has been concerned that, over the past eight years, the PIPA closure has been negatively impacting Kiribati foreign tuna vessel licence fee revenue which is a critical source of income for Kiribati. These losses are difficult to justify if, as these new analyses suggest, there is little tuna conservation benefit resulting from the PIPA. The Government has decided to re-open the PIPA to tuna fishing from January 2023, and that decision is supported by the results of this work.”
Simon Nicol, Principal Fisheries Scientist (Fisheries & Ecosystem Monitoring & Analysis): “large MPAs like these may provide benefits where fisheries exploit fairly sedentary species and impact habitats but provide only modest contributions to conserving stock-wide abundance of tuna. Additionally, they can disrupt benefits to Pacific Island countries with processing and service industries, whose competitive advantage relies on their proximity to fishing grounds for the vessels that supply their canneries or use their transhipment and service facilities”.
John Hampton, Chief Scientist at SPC’s Fisheries, Aquaculture and Marine Ecosystems Division: “Tropical tunas such as skipjack and bigeye tuna have a wide distribution in tropical and sub-tropical waters of the Pacific, and are capable of spawning anywhere where the water temperature is greater than about 25°C. Their larvae drift in the surface water currents, and as they grow they are able to move widely through the region. So closing off one part of the area tends not to offer much if any protection to species like this.” In addition, “What we tend to see when areas like the PIPA are closed is that the vessels that would have fished there simply move their activities to adjacent areas, which again limits their conservation effectiveness, at least for tuna.”
“Many countries in the Pacific region have implemented MPAs motivated in part by perceptions of how they would positively impact tuna stocks. This study shows that some of these perceptions were probably overly optimistic. We encourage evaluations like this one, based on the best scientific information on the biology of the stocks and fisheries concerned, be undertaken prior to MPAs being implemented.”
As said before, read the original for free! I just quote below the abstract and the last part of the discussion.
Abstract
Large-scale, no-take marine protected areas (MPAs) have been established in several locations in the Pacific and expansion of such areas to reach 30% of the ocean area is actively promoted in some quarters. Justification for the establishment of large oceanic MPAs often includes the conservation benefits that they would bring for tuna stocks, which are the subject of important commercial fisheries in the Pacific. The aim of this paper was to evaluate the conservation efficacy of an existing MPA, the Phoenix Islands Protected Area (PIPA) and a series of large hypothetical MPAs each constituting approximately 33% of the western and central Pacific Ocean, for two important and contrasting tuna species, skipjack and bigeye tuna. The evaluation was conducted by comparing control and counterfactual simulations in which the estimated population and fishery dynamics of the species were modelled using a high-resolution modelling framework known as SEAPODYM (Spatial Ecosystem And Population DYnamics Model). We found that stock-wide conservation benefits of the PIPA for these species, assuming that total fishing effort is maintained, to be weak to non-existent, and only modest increases in spawning biomass of both species occur within and in the near vicinity of the PIPA itself. For the larger 33% hypothetical MPAs, changes in stock-wide spawning biomass were estimated to be -0.1% to +5.8% for skipjack tuna and +4.8% to +12.0% for bigeye tuna. Conservation efficacy of MPAs for species such as tropical tunas is limited by their wide larval dispersal and high mobility of later life stages, which spatially dissipate the protective effects of MPAs. Also, the displacement of fishing effort from MPAs to areas remaining open can have negative consequences for stocks and fisheries performance in those areas. We conclude that large oceanic MPAs are not likely to be effective frontline management tools for tropical tunas and other species having similar life history characteristics.
Discussion (last part)
The period covered by the study (1998-2019) encompasses the full range of typically observed environmental variability in the Pacific, including several strong El Niño and La Niña events, thus capturing any interactions between spatial management effectiveness and environmental variability.
Our findings have contrasted two species of tropical tuna with differing population dynamics and degrees of fishing induced biomass depletion, and should also be informative regarding the likely effects of MPAs on other widely distributed, mobile pelagic species such as yellowing tuna, whose population and exploitation characteristics lie somewhere between skipjack and bigeye tuna. However, our examples do not include species whose biomass has been depleted to levels below biological sustainability limits or stocks that systematically migrate to discrete spawning grounds. How MPAs might contribute to the conservation of pelagic stocks with these characteristics remains untested. No tropical tuna stocks in the WCPO have been depleted to levels below their biological sustainability levels (Hare et al., 2021). Similarly, while stock structure for tropical tuna stocks in the Pacific remains uncertain (Moore et al., 2020), the most recent information from genetic studies has not detected strong evidence of fidelity to discrete spawning grounds (Grewe et al., 2015; Anderson et al., 2020; Natasha et al., 2022).
We recognise that large oceanic MPAs such as the PIPA may have conservation value in areas not analysed in this paper, for example in the protection of coral reef ecosystems and their resident species that might otherwise be heavily fished. However, where the objectives of, and justification for, MPAs include enhancing the conservation of widely distributed pelagic species, this should be carefully evaluated during the planning stage, for example using methods such as those of Ovando et al. (2021) and that presented in this paper. This would allow expectations to be realistic and evaluated against the likely economic and social costs and benefits that would occur.