Shahar Chaikin

Long-term warming reduces fish biomass, but heatwaves shift it Nature Ecology & Evolution - A large-scale analysis of changes in fish biomass over 25 years identifies average biomass declines associated with long-term warming, as well as sharp...

rdcu.be/e5Eg7

El calentamiento oceánico provoca un descenso de la cantidad de peces del 20% anual - EFE El calentamiento crónico y prolongado que sufren los mares está detrás del descenso de casi el 20 por ciento anual de la biomasa de peces.

A huge thank you to @efe.com for their fantastic coverage of our new paper in Nature Ecology & Evolution today! 🌊🐟

efe.com/medio-ambien...

@mncn-csic.bsky.social
@mncn-bgcg.bsky.social
@miguelbaraujo.bsky.social
@jdgonzalezt.bsky.social

Chronic ocean heating fuels ‘staggering’ loss of marine life, study finds Fish levels fall by 7.2% with as little as 0.1C of warming per decade, northern hemisphere research shows

Thank you to @theguardian.com for doing such a fantastic job communicating our findings to the public today. You can read their coverage here:
@mncn-csic.bsky.social
@miguelbaraujo.bsky.social
@csic.es

www.theguardian.com/environment/...

Long-term warming reduces fish biomass, but heatwaves shift it - Nature Ecology & Evolution A large-scale analysis of changes in fish biomass over 25 years identifies average biomass declines associated with long-term warming, as well as sharp decreases and increases in biomass associated wi...

The paper can be fully accessed here:
www.nature.com/articles/s41...

Static quotas may fail. We urgently need:
1️⃣ #Climate-ready-plans to rapidly protect warm-edge fisheries during heatwaves.

2️⃣ #Transboundary cooperation as fish shift borders.

3️⃣ Long-term planning against an overall, global biomass loss.

⚠️ THE CLIMATE TRAP (For fisheries managers): Sudden increases at the cold edge look like healthy stocks. But these gains can be "transient".

If we increase catch quotas based on short-term heatwave booms, we may risk collapsing the stock when temperatures normalize.

🌡️ THE LOSERS: Populations at the warm edge of their range are declining in biomass, plummeting up to 43.4%.

❄️ THE WINNERS: Cold-edge populations actually thrive in warmer years, increasing by up to +176%.

But short-term marine heatwaves disrupt this trend, creating a mixed landscape of "winners" and "losers".

We found that a population's fate depends on its "thermal position" within the species' geographic range.

To understand this, we analyzed >700k biomass change estimates across ~34,000 #fish populations (1,566 species) across the Northern Hemisphere (1993–2021).

The baseline is grim: chronic long-term #warming acts as a dominant stressor, driving annual #biomass declines of up to 19.8%. #climatechange

Are warmer oceans good or bad for #fish? 🐟 The answer is a dangerous paradox. Our new paper in @natecoevo.nature.com shows how marine heatwaves may create “fake” fish gains that mask a large-scale crash. Read our findings here: www.nature.com/articles/s41...

@mncn-csic.bsky.social #ClimateChange

Degradation of fish food webs in the Anthropocene The decrease in body size driven by the selective species turnover is widely altering fish food web topology and function.

New paper out examining fish food web degradation in the Anthropocene. We show the structure of aquatic food webs are changing-- even when species richness doesn’t. These signals are strongly associated with decreases in body size within fish communities. www.science.org/doi/10.1126/... 🌐🐠🐡🦈🐟

We are proud to unveil the world’s longest underwater timelapse, starting May 1st 2023 and running 1,000 days through January 28, 2026. This 10fps period covers summer 2023’s coral bleaching mortality event, but then recovering and growing through ‘24 & ‘25 into ‘26 #coralcitycamera

We can’t assume "evolutionary familiarity" protects these new ecosystems. To manage the #Anthropocene effectively, we must evaluate newcomers on a case-by-case basis, regardless of how they got there. 🌍🛡️ #Conservation #ClimateChange #Bioflow

Finally, let’s talk impact. 📉 Whether a species is a human-mediated introduction or a range-expanding climate migrant, it can become invasive. Even species of high conservation value tracking its cold edge can fundamentally reformat the structure and function of the recipient community.

The authors argue:
1️⃣ "Invasion" is a biogeographic fact, not a measure of harm.
2️⃣ "Natural range expansions" are a blurry concept when climate change is the force.
3️⃣ Let’s embrace "Global Bioflow" to describe the Anthropocene reformatting of our biospheres.

The concept of biological invasions in the Anthropocene: introductions and range expansions Abstract. In the warming world of the Anthropocene, as well as classically, biological invasions include introductions (introduced species) and range expan

We should not isolate #range_expansions and #Introductions! 🌊🦀

"An invasion is an invasion". Whether a species arrives via ballast water or a warming-driven poleward shift, it is a historical newcomer to that community.

Essential reading for anyone in #Biogeography or #InvasionEcology

onlinelibrary.wiley.com/doi/10.1111/...

The thermal position of marine population matters for #kelp persistence in the face of #marineheatwaves
Warm-edge populations of foundation species suffer more from acute short-term warming compared to cold-edge ones.
#goldenkelp #climatechange
onlinelibrary.wiley.com/doi/10.1111/...

Politics can ignore the climate, but the ecosystem is already reacting, and not positively...
#ClimateChange #MarineScience #Israel #DeepSea #Research

Fish depth redistributions do not allow maintenance of abundance in a region of rapid change For marine fishes, stressors such as ocean warming, biological invasions, and fisheries are suggested to drive depth redistributions. However, it is uncertain whether depth redistribution can act to ...

But fleeing deep isn't saving them. Data shows that even species shifting deeper are losing abundance. There is no perfect refuge.
nsojournals.onlinelibrary.wiley.com/doi/full/10....

Across the Mediterranean, cold-water species are deepening to escape rising temperatures. The warming impact is real.
onlinelibrary.wiley.com/doi/ftr/10.1...

Israel’s gov considers quitting the Paris Agreement, calling the climate crisis a "hoax". The Trump effect is sadly taking us down...
So much lack of responsibility and #egoism
May this government fall soon.
#ClimateChange #MarineScience #ocean #Research #Israel #climate_crisis

It was pleasure attending the TIBS conference in Aarhus! I had some fantastic discussions with researchers on how we can better quantify the impacts of climate change on marine species. Leaving with new ideas and collaborations. 🌊🐟
@tibsaarhus2026.bsky.social #oceans #fish @biogeography.bsky.social

Link to data:
zenodo.org/records/1809...

Link to paper:
ejournals.epublishing.ekt.gr/index.php/hc...

We provide depth, abundance, and size data for 230 fish species in the Red Sea & East Med. The Use: Vital for testing if warming drives species deeper or if invasives displace natives. The Finding: 42% of species were found at novel depths, mostly extending deeper than previously recorded.

📢 We’ve published a comprehensive depth dataset for 230 fish species in the Eastern Med & Northern Red Sea. Derived from systematic stereo-BRUVs surveys, it includes: Modeled central depth niches🔹 Abundance🔹 Body size🔹habitats
(link in thread below)
#data #fishes #marine #invasions #depth #aliens

Does ocean warming mean fewer fish? It’s complicated. 🐟
We analyzed 33k+ populations and found that while long-term warming drives declines, heatwaves create sharp "winners" and "losers" at range edges.
🗓️ Fri, Jan 9 | 14:10 - 15:40📍Session: Aquatic Biogeography #TIBS2026 @miguelbaraujo.bsky.social

Another successful lab retreat at @miguelbaraujo.bsky.social Lab!

Thanks everybody for providing important, instructive comments on binding fish biomass data with species-level thermal limits. This project is about to be very interesting.
#macroecology #macrophysiology #climatechange

I wonder if kids growing up in the third panel know what used to be underneath the pavement. Does the concrete hold the memory of the field? #Solastalgia #ShiftingBaselineSyndrome #UrbanEcology #Anthropocene