Sign in

Dr. Catherine Macdonald

@drcatmac.bsky.social
10K followers 624 following 532 posts

Marine scientist and teacher Field School & University of Miami. Director of sharktagging. NatGeo Explorer. Shark & ray ecology, biology, conservation. She/her.

PostsRepliesMedia
Reposted by Dr. Catherine Macdonald
David Shiffman, Ph.D. 🦈 @whysharksmatter.bsky.social · 18h
🤔
The America.gov search again correctly describing that the Trump administration is breaking the law.
1243
Reposted by Dr. Catherine Macdonald
SICB journals @sicbjournals.bsky.social · 17h
IOB "Cephalofoil curvature and sexual #dimorphism In both locations, males had more pointed cephalofoils than females, as exemplified in Fig. 5. from Liu et al A Head of the Curve: Bonnethead #Shark (Sphyrna tiburo) Cephalofoil #Morphology and Trophic #Ecology doi.org/10.1093/iob/...
Differences in cephalofoil shape between females and males were not always visually distinct but a Tukey post-hoc test revealed significant differences between sexes (Fig. 6). Female cephalofoils were pointier in immature individuals and became significantly rounder with maturity in both Biscayne Bay and Tampa Bay. Mature Tampa Bay females had the roundest cephalofoils. Male cephalofoils also trended towards the cephalofoil becoming rounder with maturity (clasper calcification)."
0133
Reposted by Dr. Catherine Macdonald
Craig Pittman @craigtimes.bsky.social · 29/09/2026
New study finds #Florida waterway, Biscayne Bay, provides critically important refuge for sharks & rays. www.wlrn.org/environment/... via @jenstaletovich.bsky.social
wlrn.org
Biscayne Bay provides a critical refuge for sharks and rays, new global study finds
A first-of-its-kind shark and ray mapping effort found the bay, along with waters off the southern Everglades and a tiny South Florida key, plays an essential part in their survival. “Biscayne Bay is ...
0177
Reposted by Dr. Catherine Macdonald
Jenny Staletovich @jenstaletovich.bsky.social · 29/09/2026
Biscayne Bay provides a critical refuge for sharks and rays, new global study finds www.wlrn.org/environment/...
wlrn.org
Biscayne Bay provides a critical refuge for sharks and rays, new global study finds
A first of its kind shark and ray mapping effort found the bay, along with waters off the southern Everglades and a tiny South Florida key play an essential part in their survival. “Biscayne Bay is Mi...
0183
Dr. Catherine Macdonald @drcatmac.bsky.social · 29/09/2026
@emilyyeager9.bsky.social they’re at it again
261
Reposted by Dr. Catherine Macdonald
IUCN SSC Marine Conservation Committee (MCC) @sscmarine.bsky.social · 26/09/2026
NEW PUBLICATION ALERT Read the latest publication released by the IUCN SSC Shark Specialist Group with an update on the Important Shark and Ray Areas (ISRA) project: North American and Caribbean Atlantic: A regional compendium of Important Shark and Ray Areas Read here: doi.org/10.59216/ssg...
1115
Reposted by Dr. Catherine Macdonald
Coral City Camera @coralcitycamera.bsky.social · 27/09/2026
No fear! The Rainbows follow Scarface through Coral City ✌️🌈🦜🐟🍋🦈 #lemonshark #sharksofcoralcity #scarface #nofear #coralcitycamera
241352
Reposted by Dr. Catherine Macdonald
Trevor A. Branch @trevorabranch.bsky.social · 25/09/2026
Concern that executive action on recreational fishing and shark fishing may threaten the status of US fisheries as being well-managed, sustainable and science-based www.theguardian.com/us-news/2026...
theguardian.com
Trump’s executive order on recreational fishing is a ‘giveaway of fish and ocean ecosystem’, advocates warn
Federal agencies told to prioritize recreational fishing and to reconsider scientific standards as well as regulations
0117
Reposted by Dr. Catherine Macdonald
Dean Napolitano @dinonapolitano.bsky.social · 25/09/2026
“Thousands of the salmon were recorded passing a former dam site in 2024 and 2025, researchers say, and have reoccupied nearly the full extent of their known historical range.” By Rebecca Dzombak
nytimes.com
Salmon Are Thriving After Klamath Dam Removals, Study Finds (Gift Article)
The first fall runs of chinook salmon since the project in California and Oregon was completed have surpassed researchers’ expectations.
14784199
Reposted by Dr. Catherine Macdonald
IUCN SSC Shark Specialist Group @iucnshark.bsky.social · 25/09/2026
NEW PUBLICATION ALERT | 259 important shark, ray, and chimaera habitats mapped across North America and the Caribbean New additions to the global ISRA eAtlas reveal major migration corridors, nursery grounds, and aggregation sites across Atlantic, Caribbean and Pacific waters.
187
Reposted by Dr. Catherine Macdonald
Robin Hayward 🌳 🏳️‍⚧️ @canopyrobin.com · 25/09/2026
We're publishing new guidance to support trans people who do fieldwork (any work outside the office)! Now we need your help to get them seen so please share! inclusivefieldwork.leeds.ac.uk/trans/
a cartoon of three fieldworkers. One has a small trans flag. The logos of the university of leeds, research england, and canopy robin are shown, as well as the URL: InclusiveFieldwork (dot) Leeds (dot) AC (dot) UK (slash) trans
15597444
Reposted by Dr. Catherine Macdonald
David Shiffman, Ph.D. 🦈 @whysharksmatter.bsky.social · 22/09/2026
My latest for @therevelator.org is all about the important shark and ray areas project, a global-scale collaboration that has identified over 1,000 places significant for migration, reproduction, and more. 🧪🌎🦑🦈 To Save Sharks and Rays, Protect These Places therevelator.org/save-sharks-...
therevelator.org
To Save Sharks and Rays, Protect These Places • The Revelator
The Important Shark and Ray Areas project has identified thousands of critical habitats for some of the world’s most threatened fishes. Now saving these sites is up to us.
15735
Reposted by Dr. Catherine Macdonald
Gettin' Fishy With It Podcast @gettinfishypod.bsky.social · 17/09/2026
Today is #worldmantaday and we are throwing back to our episode all about cloacal diving! Guest @emilyyeager9.bsky.social spoke to us about these amazing animals and how symbiosis may be a bit more complicated than you think! Did you know that manta are basically mobile ecosystems? Check out our ep!
Episode 78 of the Gettin' Fishy With It Podcast, entitled "Cloacal Diving and the Symbiosis continuum" with guest Emily Yeager. Released originally on May 29th 2026. Inset photos include guest Emily Yeager and a photo of a remora tail sticking out of the cloaca of a manta.
1139
Dr. Catherine Macdonald @drcatmac.bsky.social · 18/09/2026
This is a legally and morally indefensible argument with horrifying potential repercussions for threatened species and habitats.
01311
Reposted by Dr. Catherine Macdonald
Ben Goldfarb @bengoldfarb.bsky.social · 17/09/2026
“Felling a tree is not a take of the bats roosting in it unless the tree is felled for the purpose of killing or capturing them.” The @USFWS's new interpretation of the Endangered Species Act, as revealed by Nesvik's memo, is the perfect blend of evil and stupidity. www.nytimes.com/2026/09/16/c...
nytimes.com
Trump Administration Moves to Gut a Core Endangered Species Protection
An internal memo reinterprets the law so that only the intentional killing of animals, not collateral harm, is illegal.
38030
Dr. Catherine Macdonald @drcatmac.bsky.social · 17/09/2026
Throwback this #WorldMantaDay to our paper on the little (and sometimes not so little) personal-space-violating fish mantas would probably like to forget.
120
Dr. Catherine Macdonald @drcatmac.bsky.social · 16/09/2026
I know there are many things to be righteously, importantly angry about, and many of them are more important than this decision (!) …and yet, I hope you all will still find it in yourselves to save just a little anger to deploy on behalf of science and scientists, too.
05322
Reposted by Dr. Catherine Macdonald
Ada Palmer @adapalmer.bsky.social · 09/09/2026
Chinook salmon have recolonised 88% of their historic range on the Klamath River, with more than 13,000 fish passing the old Iron Gate Dam site in 2025, up from 7,700 the year before. Two years after the dams’ removal, it’s going better than anyone predicted. buff.ly/pToC9gB #ShareGoodNewsToo
nature.com
Rewilding the upper Klamath River Basin: rapid recolonization of Chinook salmon following the world’s largest dam removal - Scientific Reports
Scientific Reports - Rewilding the upper Klamath River Basin: rapid recolonization of Chinook salmon following the world’s largest dam removal
182507840
Reposted by Dr. Catherine Macdonald
Trevor A. Branch @trevorabranch.bsky.social · 09/09/2026
This is seismic news for fisheries scientists. Northern cod is *the* iconic symbol of total fisheries collapse due to overfishing (and other factors) *and* the iconic symbol of a complete failure to recover for decades afterwards. This is like announcing the complete recovery of bison on land.
8576732174
Reposted by Dr. Catherine Macdonald
Save Our Seas Foundation @saveourseas.bsky.social · 07/09/2026
One young researcher discusses the project that offered the first valuable insight into marine science, from fieldwork to publication, reflecting on the fieldwork, mentorship and practical experience that shaped his path into marine science. More below in Ryan McMullen’s blog.
saveourseas.com
Starting ‘em young: rethinking how we mentor undergraduate student researchers to succeed in today’s ever-changing science landscape
For many marine scientists, their undergraduate years are a time of unparalleled independence, growth, and self-discovery.   During no other period of one’s life is there such freedom to pursue one’s ...
0125
Reposted by Dr. Catherine Macdonald
Science Magazine @science.org · 04/09/2026
Butterfly populations across the U.S. are in alarming decline, a 2025 Science study found. ⁠ The authors note that butterflies have the potential for rapid recovery under favorable conditions, showing the importance of proactive conservation strategies.⁠ scim.ag/46vegsb #NationalWildlifeDay
Rapid butterfly declines across the United States during the 21st century
17635
Reposted by Dr. Catherine Macdonald
Trevor A. Branch @trevorabranch.bsky.social · 04/09/2026
The US House passed the Northeast Lobstermen Protection Act (H.R. 9436) by a vote of 219-196, which stops NOAA from protecting endangered right whales through to 2035 by requiring more expensive ropeless lobster pots. 1/n defenders.org/newsroom/hou...
defenders.org
House Gambles with Survival for North Atlantic Right Whales in Latest Vote to Delay Protections
The House of Representatives voted to pass H.R. 9436, a bill that will delay conservation protections for critically endangered North Atlantic right whales.
51712
Reposted by Dr. Catherine Macdonald
Rebecca Solnit @rebeccasolnit.bsky.social · 01/09/2026
Protest that endures, I think, is moved by a hope far more modest than that of public success: namely, the hope of preserving qualities in one's own heart and spirit that would be destroyed by acquiescence. Wendell Berry, What Are People For?
121173350
Reposted by Dr. Catherine Macdonald
Tom Near @tjnear.bsky.social · 29/08/2026
1/11 🐟 2nd new preprint today from @chasedbrownstein.bsky.social We investigated how losing the swim bladder, the organ that most fishes use to control their buoyancy, has shaped the diversity of ray-finned fishes over 90 million years of Earth history. The results surprised us. 🧵
110943
Reposted by Dr. Catherine Macdonald
Coral City Camera @coralcitycamera.bsky.social · 28/08/2026
Today day was sharky, very very sharky! Three species, nurse, lemon, and bull; more than fifty passes!! 🩺🦈🍋🦈🐂🦈 #nurseshark #lemonshark #bullshark #sharksofcoralcity #coralcitycamera
455597
Reposted by Dr. Catherine Macdonald
Joshua Weitz @joshuasweitz.bsky.social · 25/08/2026
NSF just announced its GRFP solicitation due in October - deadline varies by field: www.nsf.gov/funding/oppo... Now for the bad news... * NSF estimates they will issue 1,500 awards, down from 2,500+ last year. * NSF removed STEM Education and Learning Research as a Major Field.
nsf.gov
NSF Graduate Research Fellowship Program (GRFP)
6139169
Reposted by Dr. Catherine Macdonald
Fredrik Jutfelt 🐠 @jutfelt.bsky.social · 24/08/2026
Come join us, PhD and postdoc positions! Please spread! Supervisor @patricepottier.bsky.social (patricepottierlab.com), me as co-supervisor. Impacts of climate change on different life-stages in fish.🐟🧪 PhD web103.reachmee.com/ext/I005/103... Postdoc web103.reachmee.com/ext/I005/103...
06770
Dr. Catherine Macdonald @drcatmac.bsky.social · 24/08/2026
Yes hello when your swamp is on fire is that A) bad or B) very bad? Asking for a region.
193
Reposted by Dr. Catherine Macdonald
Coral City Camera @coralcitycamera.bsky.social · 22/08/2026
Scarface checks in. The injury from a fight with a fisherman continues to heal from last year when the corners of his jaw was completely shredded. Sadly his jaw may never heal. He’s a bit skinnier than we’d like to see but he must be eating well enough to keep on swimming ✅🍋🦈 #coralcitycamera
14832145
Reposted by Dr. Catherine Macdonald
David Shiffman, Ph.D. 🦈 @whysharksmatter.bsky.social · 20/08/2026
I started my Ph.D. program 15 years ago this week. Which means I've now known @drcatmac.bsky.social and @drjuliawester.bsky.social for 15 years! I really hit the lottery with my Ph.D. cohort!
Julia, Catherine and I, along with other friends, at my wedding a few weeks ago.
3371
Reposted by Dr. Catherine Macdonald
Minorities in Shark Sciences @misselasmo.bsky.social · 19/08/2026
There are only 5 tickets left! 🎟️ Are you ready to experience sharks beyond what you see on a screen? Join us on September 27 as we head out on a live research vessel to learn about (and tag!) these amazing animals! 🦈 donate.misselasmo.org/event/shark-...
0104
Reposted by Dr. Catherine Macdonald
Dr Alex Bond @thelabandfield.bsky.social · 17/08/2026
Big new @adriftlab.bsky.social paper - we show for the first time that plastics affects seabirds at the POPULATION level. Plastic ingested as a chick reduces recruitment of birds to the breeding population. And the story is pretty grim. 🧵 www.pnas.org/doi/10.1073/...
316092
Reposted by Dr. Catherine Macdonald
Save Our Seas Foundation @saveourseas.bsky.social · 13/08/2026
Freckled guitarfish occur in the western Atlantic Ocean, favouring sandy, muddy or weedy shorelines near patch reefs, when not actively hunting. As with all guitarfish, they swim like sharks usually do: through side-to-side sweeps of their tail. 📷: Bryant Turffs | © Marine Megafauna Foundation
072
Reposted by Dr. Catherine Macdonald
Coral City Camera @coralcitycamera.bsky.social · 10/08/2026
Graysby shows off what nice teeth it has #graysby #grouper #teeth #showoff #coralcitycamera
556597
Reposted by Dr. Catherine Macdonald
Frank Burdon @fburdon.bsky.social · 03/08/2026
What co-benefits do we gain when planting trees along stream margins? We don't fully know. Fully-funded PhD going now — mapping food webs across Mt Taranaki's "ring of restoration" 🌱🐟 Please repost among your networks Email: frank.burdon@waikato.ac.nz
21515
Reposted by Dr. Catherine Macdonald
Coral City Camera @coralcitycamera.bsky.social · 07/08/2026
We love our eels in Coral City! (That’s a moray!) 🙌🐉 #spottedmoray #moray #eel #thatsamoray #coralcitycamera
14715134
Reposted by Dr. Catherine Macdonald
Woods Hole Oceanographic Institution @whoi.edu · 06/08/2026
In 1963, WHOI biologist Dick Backus set his sights on a question that had puzzled scientists for decades: what caused the daily vertical movement of plankton? The sun or an internal clock? During an eclipse, Backus was able to monitor that the migration was triggered by changing light levels!
Whoi biologist, Dick Backus, is using a machine to see if plankton are migrating with the eclipse. The room is filled with complex equipment and wires, suggesting a scientific or technical environment.
03410
Reposted by Dr. Catherine Macdonald
David Shiffman, Ph.D. 🦈 @whysharksmatter.bsky.social · 03/08/2026
ICYMI, the longest-ever post on Southern Fried Science contains answers to 50 (ish) of the most commonly-asked questions about careers in marine biology, answered by me and a panel of experts. Please share! www.southernfriedscience.com/marine-biolo...
southernfriedscience.com
Marine Biology Career Advice
You asked us questions about marine biology careers, and our panel of experts answered them! In April, I solicited your questions about careers in marine biology, and we received nearly 100 questio…
24320
Reposted by Dr. Catherine Macdonald
Chuck “Charles” Bangley, PhD @dogfishwalker.bsky.social · 31/07/2026
Dusky sharks have been a prohibited species in US fisheries since 1999. These big adults are a sign that policy is working. A fully grown dusky shark can reach 14 feet in length and stand toe-to-toe with white sharks in the food web.
2197
Reposted by Dr. Catherine Macdonald
Coral City Camera @coralcitycamera.bsky.social · 28/07/2026
Our bull shark security squad keeping all the haters at bay 🙅‍♂️😤🐂🦈 #bullshark #sharksofcoralcity #sharkweekiseverydayincoralcity #shark #coralcitycamera
749176
Reposted by Dr. Catherine Macdonald
Charles Bergquist @cbquist.bsky.social · 28/07/2026
BONUS: you can hear @whysharksmatter.bsky.social say 'Wow!' in some tape at the top. Thanks to him for the invitation to join.
131
Reposted by Dr. Catherine Macdonald
Charles Bergquist @cbquist.bsky.social · 28/07/2026
Today on the @scifri.bsky.social podcast, hear @drcatmac.bsky.social tell the SHOCKING TRUTH about Megalodon!!! Plus, a remora's er, um ..'cloacal diving.' And other fun stuff. podcasts.apple.com/us/podcast/t...
podcasts.apple.com
Tracking shark populations, one shark at a time
Podcast Episode · Science Friday · July 28 · 18m
145
Dr. Catherine Macdonald @drcatmac.bsky.social · 28/07/2026
Thanks for this, because at least now I will have some idea what’s happening when someone inevitably asks me an otherwise incomprehensible question about this at a public talk.
2355
Reposted by Dr. Catherine Macdonald
Dr Craig R McClain @drcraigmc.bsky.social · 26/07/2026
The Japanese spider crab spans nearly four meters claw to claw, the largest arthropod alive. Why? Cold, deep water lets an animal grow slow and live long, and because water carries a weight that legs on land never could. On land an arthropod this size collapses. 🦀 🧪 #HowToBuildAGiant #marinelife
38020
Reposted by Dr. Catherine Macdonald
David Shiffman, Ph.D. 🦈 @whysharksmatter.bsky.social · 25/07/2026
www.cracked.com/article_3616... Love this Cracked article about my research with @whitenacklab.bsky.social @drcatmac.bsky.social
cracked.com
5 Nonsense Things Shark Week Taught Us, According to Science
Every shark ever has not been killed for shark-fin soup
37528
Reposted by Dr. Catherine Macdonald
Save Our Seas Foundation @saveourseas.bsky.social · 22/07/2026
In Lunyuk, 96% of fishers are willing to release threatened bycatch if compensated for lost income. Yet, the true insight of the trial shows that when fishers don't absorb the financial blow of conservation alone, it opens a door that shifts local values towards a more sustainable future.
saveourseas.com
Changing fisher behaviour is challenging - it takes time for values to be embedded
Changing fisher behaviour sounds simple from the outside. We can design a rule, offer an incentive, or ask people to release threatened species. But in a small fishing community like Lunyuk, change is...
0137
Reposted by Dr. Catherine Macdonald
David Shiffman, Ph.D. 🦈 @whysharksmatter.bsky.social · 19/07/2026
There was an interactive Directory of explorers! We found @drcatmac.bsky.social !
231
Dr. Catherine Macdonald @drcatmac.bsky.social · 15/07/2026
We need to collaboratively imagine alternatives: there are no transformative futures that just replicate existing logics, ethics, or power structures.
061
Reposted by Dr. Catherine Macdonald
High Seas Alliance @highseasalliance.bsky.social · 14/07/2026
🦈 Highly migratory sharks and rays don’t recognise geopolitical boundaries, but they are equally affected by the global effects of destructive activities, pollution & climate change. The High Seas Treaty can effectively protect them with the establishment of High Seas #MPAs. #SharkAwarenessDay
A stylized illustration of a whale shark with faint images of world maps in the background. The text reads, "Sharks Know No Borders," and the hashtag "#60toGlobal" is in the bottom right corner.
04618
Dr. Catherine Macdonald @drcatmac.bsky.social · 15/07/2026
While the movie includes scarcely a lick of science, I think his performance captured some of the best things about being a scientist—the curiosity and wonder that drives us, the passion that sustains our work, and the thrill of discovery.
1142