Juan Carvajal-Quintero

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

✨ March Public Lecture - Free & Open to All! ✨

Join the Nova Scotian Institute of Science on Monday, March 2nd for another exciting public lecture!

Taking place online via Zoom and in-person at Dalhousie University.

@dalhousie.bsky.social

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/... 🌐🐠🐡🦈🐟

School of fish / by Toby Matthews, Ocean Image Bank

What happens when fish communities shift towards smaller species?🐟
Global study led by alumnus @juancarvq.bsky.social shows widespread changes in food webs across marine & freshwater systems. Even where species numbers stayed stable, interactions & body size changed.
🔗 www.idiv.de/smaller-fish...

Trait-explicit approaches cast new light on fragmentation effects on biodiversity While negative effects of landscape fragmentation on biodiversity are well documented, recent evidence suggests positive or neutral effects may also be common. The mechanisms driving these contrasting outcomes cannot be understood without assessing how species traits influence responses to landscape and patch characteristics. Here, we show that three key elements can enhance predictability of fragmentation effects across scales: (i) the trait distribution of the regional species pool; (ii) the relationship between taxonomic and trait diversity; and (iii) the effects of the landscape matrix on the distribution of species traits. Considering these elements will facilitate the development of generalizable hypotheses on the consequences of fragmentation across diverse taxonomic groups and regions, with broad applicability to ecology and conservation.

Online now: Trait-explicit approaches cast new light on fragmentation effects on biodiversity

📢New paper!

🐟📚Using fish stomach contents spanning over a century, we reveal long-term diet shifts (from larger bivalves to smaller opportunistic prey) in demersal fish species in the western North Sea.

🔗 Open access in Fish & Fisheries: onlinelibrary.wiley.com/doi/epdf/10....

Honoring the life of James A. Estes, a pioneering ecologist.

Honoring James A. Estes, a pioneering ecologist whose research on sea otters in Alaska revealed how predators shape entire ecosystems. His work helped define the concept of trophic cascades and inspired generations of ecologists. Read the PNAS Retrospective: https://ow.ly/leKs50XrKBH

Read the accompanying News & Views commentary from Samuel Macaulay 👇

"Synthesizing stressor–biodiversity relationships" www.nature.com/articles/s41...

🌊Taxonomic, phylogenetic, and functional β-diversity and its components respond distinctly to nutrients and herbivory in algae. New functional β-diversity metrics, outperforming the conventional ones, will benefit the biodiversity field👇
buff.ly/3pfult9

🦭 New study reveals overlooked intraspecific variation in prey quality and its influence on predator energy budgets. By identifying key ecological drivers, they emphasize the need to integrate such variability into bioenergetic models.

Read the full paper here! ➡️ buff.ly/vecdcwH

Si están o andarán por Medellín, Colombia, están invitadxs a esta charla en la Universidad de Antioquia en el marco del primer curso de Macroecología para el posgrado de Biología de la UdeA.

Si conoces a algun/a interesadx, avísale!

Society for Freshwater Science (SFS) 2026 Annual Meeting Spokane, WA May 17-21 logo featuring a mountains, a waterfall, and a bridge in the background and salmon and aquatic insects in the foreground. Around the edge is the meeting theme: Gathering to build resilient watersheds and communities

💡We’re now accepting workshop & special session proposals for the Society for Freshwater Science 2026 Annual Meeting.

📍 Spokane, WA
📆 May 17–21, 2026
📝 Proposals due Oct 15, 2025

🔗 Special sessions: www.sfsannualmeeting.org/special-sess...

🔗 Workshops: www.sfsannualmeeting.org/workshop-pro...

🇨🇴 at the Living the data symposium at #CSEE2025
@crcruzr.bsky.social @juancarvq.bsky.social

Go check out @jacejostles.bsky.social 's very pretty poster this evening about the science behind guppy magic and science communication. Spot I1 #evol2025

Organizer/Organisateur: Andrea Paz (@andreapaz.bsky.social), Juan Carvajal-Quintero (@juancarvq.bsky.social), Tim Parker, Timothee Poisot (@ctrlalttim.com), Diane Srivastava (@srivastavalab.bsky.social), Cristian Alexander Cruz Rodriguez & Bruno Soares (@bruno-soares.bsky.social)

Lead by my friend @gabrielmoulatlet.bsky.social and with the artistic contribution of our very own Roberto Ruiz (IG: @rob_rz), following the tradition of classic AmNat papers 🫶

Thanks to our other friends and colleagues Wesley Dáttilo and Daniel Kissling for the collab

Thanks to @idiv for funding and hosting our first working group meeting on range edge dynamics (sRED) @kemarshall.bsky.social @joeybernhardt.bsky.social @juancarvq.bsky.social @shaharchaikin.bsky.social @usuitakuji.bsky.social @emmamarjakangas.bsky.social @colingarroway.bsky.social

Authors of iDiv paper awarded W.S. Cooper Award ESA’s 2025 Cooper Award Honors Groundbreaking Work on Taxonomic Harmonization in Biodiversity Research

The 2025 Cooper Award @ecologicalsociety.bsky.social has been awarded to the authors of “Harmonizing taxon names in biodiversity data: A review of tools, databases and best practices”.
Congratulations to Matthias Grenié, @smartenwinter.bsky.social & all co-authors! 🥂🎉
www.idiv.de/cooper-award...

I’m recruiting a PhD student in macrogenetics at Dalhousie University 🇨🇦! Focus will be on the biogeography of vertebrate genetic diversity or urban evolutionary ecology.
Full ad: www.schmidt-biodiversity-lab.org/macrogenetic...
If the ad is up, applications are still open.
Please share widely! 🧬🧬

This photograph of Gale crater, Mars, was taken by the Curiosity rover at the Ubajara drill site. The rover’s 40-cm-wide tracks are visible in the foreground. The rover drilled a rock sample at this location, which was found to contain substantial amounts of siderite, an iron carbonate mineral. The siderite likely played a role in an ancient carbon cycle that affected Mars’ surface climate.

NASA’s Curiosity rover has uncovered a hidden chemical archive of ancient Mars’ atmosphere, which suggests that large amounts of carbon dioxide have been locked into the planet’s crust, according to a new Science study.

Learn more in this week's issue: scim.ag/3Ed9kOl

Signs of life on a distant planet? Not so fast, say these astronomers Bold claims of ‘biosignature’ molecules trigger an outpouring of scepticism.

A team of scientists made headlines last night with claims that they had found the “strongest hints yet of biological activity outside the Solar System”. They have met floods of scepticism.

https://go.nature.com/3Gsyr03

Global Projection of Terrestrial Vertebrate Food Webs Under Future Climate and Land‐Use Changes

📄 https://buff.ly/4gwQYVF
#foodweb #climatewarming #landusechange #biodiversity

The position will be based at Dalhousie University. Please share widely!!
@csee-scee.bsky.social
@ciee-icee.bsky.social
@biogeography.bsky.social

PhD Advertisement that reads: I am recruiting a PhD student to join MacroSize, a new international research network advancing hypotheses and theories on intraspecific body size variability in fish. The selected candidate will co-develop the project, analyze large datasets, and collaborate closely with MacroSize members, including co-leads Pablo Tedesco, Ignasi Arranz, Xingli Giam, and Juan Carvajal-Quintero. To apply, Send your CV and a motivation letter to juan.carvajal@dal.ca. Applications are open now and will be reviewed on a rolling basis. Start date September 2025 (flexible).

PhD project alert! 🚨 I'm recruiting a PhD student to join my lab and the MacroSize network to investigate the trends, patterns, and processes driving intraspecific variation in fish body size in the Anthropocene. Exciting opportunity to explore ecological dynamics in a changing world! :) 🌎🐟🐠🐡

Cool paper showing how deforestation impacts freshwater fish communities and a nice example on connectivity between blue-green biodiversity!

One quarter of freshwater animals at risk of extinction - IUCN Red List Gland, Switzerland, 8 January 2025 (IUCN) – The largest global assessment of freshwater animals on the IUCN Red List of Threatened Species™ to date has revealed that 24% of the world’s freshwater fish...

‘One quarter of freshwater animals at risk of extinction’ iucn.org/press-releas...

One-quarter of freshwater fauna threatened with extinction - Nature A global multi-taxon extinction risk assessment of freshwater fauna for The IUCN Red List of Threatened Species finds one-quarter of species to be at high risk of extinction.

One-quarter of freshwater fauna threatened with extinction | Nature

Illuminating the multidimensional contributions of small-scale fisheries - Nature A study aimed at revealing the role of small-scale fisheries in sustainable development shows they provide at least 40% of the global fishing catch and affect the livelihoods of 1 in 12 people in the ...

Small-scale fisheries account for 40% of global catch, providing 20% of micronutrient intakes for up to 2.3 billion people and livelihoods for 1 in 12 people.

Huge effort involving @fao.org & 800 experts, out now in @nature.com

www.nature.com/articles/s41...

Three must read papers for PhD students. #scisky #PhD #science #research #academicsky

1. The importance of stupidity in scientific research

Open Access
journals.biologists.com/jcs/article/...