Showing posts with label fisheries. Show all posts
Showing posts with label fisheries. Show all posts

Friday, June 26, 2026

June 2026 science summary

Jon bike sailing in Scotland

Eyyyy!


I spent half of May on vacation visiting friends in Scotland and Germany so read less science than usual. But the three articles I have seem broadly interesting. To deepen my review, AFTER I finished my write up I asked Elicit (an AI tool) to look at each paper for 1-3 key points or findings or limitations not mentioned in the abstract that might be both important but non-obvious. It actually caught 1-2 things I decided to include in each summary: some I'd missed, most I'd noted and didn't see as important but on reflection decided they were worth including.

If you know someone who wants to sign up to receive these summaries, they can do so at http://subscribe.sciencejon.com (no need to email me).


CLIMATE CHANGE:
Can’t wait for the next IPCC climate report? Van Vuuren et al. 2026 lists the scenarios they plan to model in that report (results likely in a year or so). These will replace the RCPs. See section 2.3 for the full list, and note the shift to plain language and emphasis on plausibility: “medium emission scenario” means current policies and trends continue (~3C increase by 2100), “high emissions” means as much rollbacks as is plausible (~3.5C increase by 2100 but rising past that). They also have scenarios where we start high or medium but later step up action to low. We’ll have to wait to see the final model runs, expected impacts (physical and socioeconomic including equity), and associated storylines of each scenario. They also note that they use a simple approach for estimation past 2100 (2150 and 2500) but reflect that over time we need to extend the horizon of more complex modeling. They also note that not all potential carbon dioxide removal approaches are included in most scenarios (see section 5).


FOREST RESILIENCE:
Wang et al. 2026 has a nice list of 10 ways to improve the climate resilience of forests. Nothing brand new or surprising - except maybe the phrase "cohesive polycentric governance frameworks" for a coordinated mix of autonomous and shared decision-making across Indigenous people, governments, carbon market managers, etc. The abstract and Fig 2 have the full list; in addition to governance they have: diversity, disturbance, protection, restoration, adaptive mgmt, sustainable forestry / logging, monitoring, learning, and collaboration. Table 1 lists some examples of climate stresses and related forest vulnerabilities and resilience strategies. Figure 1 is an interesting map attempting to split 'natural' and 'social-ecological' forests (based on Forest Landscape Integrity Index as per Grantham et al. 2020 which docks points for forest cover loss and other observed human pressures plus loss of connectivity). Of the 10 - they assert that diversity and decentralization of authority are the most essential, but recognize limitations in seed sources, trade-offs (e.g., prescribed fire affecting human health, or lower timber yields w/ higher diversity and longer rotations), and cost.


OCEAN CONSERVATION:

Worm et al. 2026 provides the status of 2030 global goals to both 1) protect 30% of the ocean and 2) sustainably manage 100% of it. They look at 445 fish stocks in the 19 FAO "major fishing areas" that cover the entire ocean and collectively produce 72% of global marine fish harvest (the other 28% is from minor untracked species - which are often less well managed). They find 10% of the ocean is protected (from 2-20% by fishing area) of which 3% is either highly or fully protected (from 0.1-19%) meaning the marine protected area (MPA) is implemented w/ a management plan and a ban on damaging forms of extraction. For other non-marine people like me, "highly protected" specifically means: only small scale infrequent anchoring, only low-impact small scale unfed aquaculture, and that fishing is infrequent using a few kinds of selective low-impact gear. Sadly the paper points out big MPAs are typically in remote places w/ little fishing, avoiding conflict but also reducing the likelihood of impact and potential for coordination. The fishery management bit is more confusing: they report that 62% of the stocks (~45% of global marine fish harvest) were 'sustainably managed' using the criteria of fishing at or below a single-species maximum sustained yield, but the paper ALSO argues that's the wrong target and we need to be keeping harvest at or below a "multi-species maximum sustained yield" (see Fig 3) which is very rare. They also note that different agencies typically manage MPAs (often w/ a biodiversity focus) and fisheries (often w/ an economic and production focus), sometimes leading to poor coordination and even conflict.


REFERENCES:
Grantham, H. S., Duncan, A., Evans, T. D., Jones, K. R., Beyer, H. L., Schuster, R., Walston, J., Ray, J. C., Robinson, J. G., Callow, M., Clements, T., Costa, H. M., DeGemmis, A., Elsen, P. R., Ervin, J., Franco, P., Goldman, E., Goetz, S., Hansen, A., … Watson, J. E. M. (2020). Anthropogenic modification of forests means only 40% of remaining forests have high ecosystem integrity. Nature Communications, 11(1), 5978. https://doi.org/10.1038/s41467-020-19493-3

Van Vuuren, D. P., O’Neill, B. C., Tebaldi, C., Sanderson, B. M., Chini, L. P., Friedlingstein, P., Hasegawa, T., Riahi, K., Govindasamy, B., Bauer, N., Eyring, V., Fall, C. M. N., Frieler, K., Gidden, M. J., Gohar, L. K., Högner, A., Jones, A. D., Kikstra, J., King, A., … Ziehn, T. (2026). The Scenario Model Intercomparison Project for CMIP7 (ScenarioMIP-CMIP7). Geoscientific Model Development, 19(7), 2627–2656. https://doi.org/10.5194/gmd-19-2627-2026

Wang, L., Tagesson, T., Wei, F., Dong, W., Tian, F., Duan, Z., Luan, H., & Svenning, J. (2026). Ten Strategies to Promote Climate Resilience and Sustainability of Global Forests. WIREs Climate Change, 17(3). https://doi.org/10.1002/wcc.70064

Worm, B., Clausius, E., Grorud-Colvert, K., Palardy, J. E., Pauly, D., Pike, E. P., Pikitch, E. K., Roberts, C. M., Roberts, G. E., Richmond, R. H., Schiller, L., Stuart-Smith, R. D., & Sumaila, U. R. (2026). Integrating global targets for protected areas and sustainable fisheries. Marine Policy, 191(October 2025), 107152. https://doi.org/10.1016/j.marpol.2026.107152

Sincerely,

Jon


P.s. The pic is of me bike sailing (aka "land yachting" for some reason) on a beach in St. Andrews, Scotland. It is a lot of fun!


Monday, May 1, 2023

May 2023 science summary

Nut Case by Katie Hudnall

Greetings,

Does spring feel like it came early or late? It's not just you! DC leafed out 3 weeks ahead of schedule.

This month is a bit of a grab bag: three papers on fishery management, one on assisted migration for wildlife, one on forests & fire, and one on the role of wildlife in climate mitigation that I found pretty misleading.

If you know someone who wants to sign up to receive these summaries, they can do so at http://bit.ly/sciencejon (no need to email me).

CLIMATE CHANGE & WILDLIFE:
Schmitz et al. 2023 makes a fair point but uses some egregious estimates to do so (please don't trust the estimated climate mitigation benefits). They argue that the role of animals in boosting carbon sequestration (and/or reducing soil carbon and methane emissions) in underappreciated, and they may be right. Fig 1 is a cool thought experiment looking at potential impacts of boosting animal populations in different case studies. BUT the estimate of a huge 6.41 additional Gt CO2e / yr that could be reduced via animals is based on some really weak assumptions. For example, 86% of that 6.41 Gt comes from marine fish (5.5 Gt / yr). But that 5.5 Gt comes from another report, and is actually an estimate of CURRENT fish carbon flux (not potential to increase additional sequestration via conservation) recognizing a ton of uncertainty. Their bison estimate (another 9% of the 6.41 Gt) assumes that bison start grazing ungrazed lands when in fact they'd be displacing cattle in most cases (and one of the papers they cite lists the C benefit of cattle and bison as about the same). The only other animal with a substantial contribution is grey wolves (4% of total), and it's based on a single study on net primary productivity in Michigan which ignores the albedo effect. So overall, this study starts with decent evidence but makes some really flawed assumptions about how to translate them into global climate mitigation potential.


WILDLIFE AND ASSISTED MIGRATION:

Fitzpatrick et al. 2023 looks at the potential for assisted migration (moving individual animals to different habitats, sometimes along w/ targeted captive breeding) as a form of 'genetic rescue' to restore gene flow across fragmented federally listed vertebrate populations in the US via assisted migration. They gave 222 spp a score from -1->4, with 2/3 of spp scoring 2 or higher (and thus may be candidates for assisted migration, see Fig 1b for results by type of animal, or Fig 2 for example candidate spp). Only 5% of spp. had a management plan mentioning "genetic rescue" (or the general concept), but 44% of candidate species had already used assisted migration (more frequent in fishes and mammals)). Note that italicized words are in a glossary at the end. Also note this paper does NOT include other connectivity strategies like habitat restoration, wildlife crossings, etc.


FORESTS & FIRE:
Prichard et al. 2021 is a review of several questions related to fire in US western forests (see Table 1 for the summary of questions & answers). They include whether and when/ how to use cutting trees and prescribed burns as tools for reducing wildfire risk and/or climate mitigation and/or ecological restoration. The authors argue that many dry forests (and some moist forests mixed into dry forest landscapes) historically experienced more frequent fires of low to moderate intensity (often set by Native Americans), but that these forests are now denser and more likely to have severe crown fires (especially as summers become warmer and drier). That in turn will cause some forests to be lost and shift to grasslands or other ecosystems. Read Table 1 for key takeaways, including that for many (not all) Western forests, thinning and prescribed burning are important tools. Side note: given the active debate on this topic, I asked for input from a few forest scientists deep in the lit, and they recommended this article.


FISHERY MANAGEMENT:
Cinner et al. 2019 is a 16 year study of rotational fishing / closure in Papua. They found success in compliance with the system (due to strong social cohesion driven by leaders sharing info, a "carrot and stick" approach, and lots of community participation) BUT even though closed areas rebounded, over the study period fish biomass dropped by about half. So even though the closure program worked as intended, it wasn't enough to offset overfishing when areas were open.

Cinner et al. 2012 is a study of 42 co-management arrangements for coral-dependent fisheries across 5 countries. Co-management led to more biomass than non-locally managed fished areas, and less than no-take closures (Fig 3). But see Fig 4 for key results (fish biomass was higher when markets were farther, and lower when more people replied on fishing for their primary income). They found just 54% of resource users saw co-management as improving their livelihoods (it seemed to benefit wealthier fishers w/ longer history of co-management and more agency).

Hughes et al. 2012 looks at how vulnerable different countries are to declining coral-dependent fisheries leading to reduced food security. Tables 2-4 have ratings of 27 countries vulnerability to declining fisheries impacting food security, as well as ratings of assets, flexibility, learning, and social organization. The most vulnerable countries are Indonesia, Liberia, Ivory Coast, and Kenya.


REFERENCES:
Cinner, J. E., McClanahan, T. R., MacNeil, M. A., Graham, N. A. J., Daw, T. M., Mukminin, A., Feary, D. A., Rabearisoa, A. L., Wamukota, A., Jiddawi, N., Campbell, S. J., Baird, A. H., Januchowski-Hartley, F. A., Hamed, S., Lahari, R., Morove, T., & Kuange, J. (2012). Comanagement of coral reef social-ecological systems. Proceedings of the National Academy of Sciences, 109(14), 5219–5222. https://doi.org/10.1073/pnas.1121215109

Cinner, J. E., Lau, J. D., Bauman, A. G., Feary, D. A., Januchowski-Hartley, F. A., Rojas, C. A., Barnes, M. L., Bergseth, B. J., Shum, E., Lahari, R., Ben, J., & Graham, N. A. J. (2019). Sixteen years of social and ecological dynamics reveal challenges and opportunities for adaptive management in sustaining the commons. Proceedings of the National Academy of Sciences, 116(52), 26474–26483. https://doi.org/10.1073/pnas.1914812116

Fitzpatrick, S. W., Mittan-Moreau, C., Miller, M., & Judson, J. M. (2023). Genetic rescue remains underused for aiding recovery of federally listed vertebrates in the United States. Journal of Heredity, March, 1–13. https://doi.org/10.1093/jhered/esad002

Hughes, S., Yau, A., Max, L., Petrovic, N., Davenport, F., Marshall, M., McClanahan, T. R., Allison, E. H., & Cinner, J. E. (2012). A framework to assess national level vulnerability from the perspective of food security: The case of coral reef fisheries. Environmental Science & Policy, 23, 95–108. https://doi.org/10.1016/j.envsci.2012.07.012

Prichard, S. J., Hessburg, P. F., Hagmann, R. K., Povak, N. A., Dobrowski, S. Z., Hurteau, M. D., Kane, V. R., Keane, R. E., Kobziar, L. N., Kolden, C. A., North, M., Parks, S. A., Safford, H. D., Stevens, J. T., Yocom, L. L., Churchill, D. J., Gray, R. W., Huffman, D. W., Lake, F. K., & Khatri‐Chhetri, P. (2021). Adapting western North American forests to climate change and wildfires: 10 common questions. Ecological Applications, 31(8). https://doi.org/10.1002/eap.2433

Schmitz, O. J., Sylvén, M., Atwood, T. B., Bakker, E. S., Berzaghi, F., Brodie, J. F., Cromsigt, J. P. G. M., Davies, A. B., Leroux, S. J., Schepers, F. J., Smith, F. A., Stark, S., Svenning, J.-C., Tilker, A., & Ylänne, H. (2023). Trophic rewilding can expand natural climate solutions. Nature Climate Change. https://doi.org/10.1038/s41558-023-01631-6

Sincerely,
 
Jon
 

p.p.s. The photo is of a piece at the Renwick gallery in DC. The caption says: 'A mature oak tree produces about two thousand acorns a year, but only one in ten thousand acorns reaches maturity. Hudnall explains, “I think the idea of constant, repeated, tiny attempts for success, with the understanding that most will go nowhere, became a way for me to think about slow progress toward health in my own life.” '

Friday, October 1, 2021

October 2021 science summary

Jon digging a hole with an excavator / backhoe

 

Greetings,

Before diving into journal articles, I want to highlight a blog, short video, and web map update. First, over the last several years of working in conservation, I hear more and more calls for conservation to rapidly scale effective solutions. Sometimes that's coupled with a sense of urgency that makes us think we don't have time for missteps or to do things that don't work. But this article makes a compelling case that if we want to scale fast, that means we will need a higher tolerance for the risk of failure. It's a good read! https://ssir.org/articles/entry/getting_honest_about_what_were_willing_to_risk_for_the_planet#

Want to know how (and why) to talk to "uncle Ernie" and other people who are not convinced we need to urgently act on climate change? Check out Dr. Katherine Hayhoe's interview on Jimmy Kimmel: https://youtu.be/LVjmGVufADk

The last quick update is for those of you working in South America. The latest update to Mapbiomas includes fire scars and water surface area: https://plataforma.brasil.mapbiomas.org/agua 
They have cool graphs showing changes (drops) in water area over time. The (user's) accuracy is mostly 75% or above, but it's really low in the Pantanal (see https://mapbiomas.org/metodo-agua). They saw a huge drop there (74% less water over 30 years) but it's hard to know how much of that is real. Unfortunately the high variation throughout the year makes validating annual estimates of water surface inherently tricky.

If you know someone who wants to sign up to receive these summaries, they can do so at http://bit.ly/sciencejon

CLIMATE CHANGE:
Welsby et al. 2021 ask an interesting question: what fraction of economically viable fossil fuels need to left in the ground to give us a 50% shot at limiting warming to 1.5C? The answer is pretty stark: by 2050 we need to leave 58% of oil, 59% of methane gas, and 89% of coal underground (a 3% annual reduction in oil and gas). See table 1 for their estimates by region. They note that we may need to leave even more fuels unextracted given questions about how fast we can develop "negative emissions" technology (carbon capture and storage).

Zhang et al. 2020 finds that 3.7% of total natural gas (mostly methane) extracted in the Permian basin (west Texas and SE New Mexico) is lost via leaks (w/ 4.1% lost in the Delaware sub-basin). It's a cool study using a recent satellite to estimate methane emissions, and EDF is launching a more precise satellite for this in 2022. This is a big deal because given methane has ~84 times the impact of CO2 on global warming over the next 20 years (dropping after that). So this leakage rate means that right now natural gas from the Permian has more short-term climate impact than coal (see http://blogs.edf.org/energyexchange/2013/11/05/methane-a-key-to-dealing-with-carbon-pollution/)! The authors think the leaks in this region are mostly from venting and flaring during active production (as opposed to leaks after well abandonment)


MARINE PROTECTED AREAS:
Sala et al. 2021 identify global priorities to designate as marine protected areas (MPAs), with the goal of protecting biodiversity and carbon while improving the yield of fisheries. The yield improvements come from targeting areas that are currently both overexploited and unprotected; they find protecting 9% of the ocean could boost maximum sustainable yield (MSY) from seafood by about 10% (protecting 5% increases yield by ~9%, Fig 1d,). The authors recommend protecting 28% of the ocean (not 9%) but their data seem to indicate the food benefit is the same at both levels. Fig 3 has some other interesting scenarios, including giving equal weight to food and biodiversity (3c, leading to a recommendation to protect 45% of the ocean which provides 92% of maximum fisheries benefit, 71% of max. biodiversity benefit, and 29% of max carbon benefits) or maximizing biodiversity without harming production (3d, recommending to protect 71% of the ocean which provides neither fisheries benefit nor harm, 91% of max. biodiversity benefit, and 48% of max carbon benefits). The unequal distribution of priority areas (Fig 1 & 2) raise potential equity concerns that are not addressed. Also apparently the carbon estimates do not account for additional boat travel time and thus may be optimistic. Finally: I know very little about marine ecosystems so let me know if you think my summary is wrong.

UPDATE: Concerns have been raised about the model this paper is based on, and the earlier paper this builds on has been retracted primarily due to an undisclosed conflict of interest: https://sustainablefisheries-uw.org/flawed-mpa-science-retracted/



REFERENCES:

Sala, E., Mayorga, J., Bradley, D., Cabral, R. B., Atwood, T. B., Auber, A., Cheung, W., Costello, C., Ferretti, F., Friedlander, A. M., Gaines, S. D., Garilao, C., Goodell, W., Halpern, B. S., Hinson, A., Kaschner, K., Kesner-Reyes, K., Leprieur, F., McGowan, J., … Lubchenco, J. (2021). Protecting the global ocean for biodiversity, food and climate. Nature, 592(7856), E25–E25. https://doi.org/10.1038/s41586-021-03496-1

Welsby, D., Price, J., Pye, S., & Ekins, P. (2021). Unextractable fossil fuels in a 1.5 °C world. Nature, 597(7875), 230–234. https://doi.org/10.1038/s41586-021-03821-8


Sincerely,
 
Jon

p.s. the photo above is of me driving an excavator at Diggerland, which was quite fun albeit not the greenest activity