What success looks like (5–10 years)
• Fishing mortality aligned with species’ life histories
• Species-level reporting becomes the norm
• Management completeness rises above critical thresholds
• Shark & ray populations stabilize and recover
Read the paper here: rdcu.be/eZ9n9
• 40% of global shark & ray catch comes from low- and middle-income countries
• Small-scale fisheries underpin livelihoods and food security
• Under-resourced management = high biodiversity & social risk
• Reduced fishing mortality reduces extinction & social risk, improving ecosystem functions.
Bending back the biodiversity loss curve of sharks and rays. The loss of sharks and rays to date has involved serial depletion of the largest, most evolutionary and functionally distinct species, and the increasing prevalence of smaller-bodied species that have benefited from release from predation.
Where investment has the highest leverage to bend back biodiversity loss?
Funding that strengthens:
• Species-level catch & trade data
• Compliance and enforcement
• Capacity in national agencies
• Monitoring in small-scale fisheries
→ Directly reduces fishing mortality
A theory of shark and ray conservation change. Structural drivers of shark and ray decline can be addressed through three types of measures that target trade and demand management, fisheries management, and rehabilitation.
We don’t need new frameworks — we need to connect and implement the ones we have.
Fisheries management, trade rules, compliance, and demand must align to reduce fishing mortality at scale.
Implementation is the bottleneck.
@hollieboothie.bsky.social
@sharkcolin.bsky.social
Green List Status Assessment of the Banded Wobbegong (Orectolobus halei) The recovered (blue) status compared to what the past status might have been without conservation (Conservation Legacy, green) and future status unless management continues (Conservation Dependency, orange).
Decline is not inevitable.
Where fishing mortality has been reduced — through catch limits, retention bans, or spatial protection — shark and ray populations are stabilizing or recovering.
Recoveries documented for wide-ranging and restricted-range species @charlie-huveneers.bsky.social
Progress and priorities in shark and ray fisheries management. The risk to species owing to incomplete management (‘M-Risk’, part a) can be described by Compliance, one of 19 attributes across four classes for requiem sharks and guitarfishes
Gaps in catch limits, compliance, and enforcement mean fishing mortality stays high even where policies exist.
Where management is complete, risk is lower and recovery is possible.
@hollieboothie.bsky.social
@sharkcolin.bsky.social
Read the paper here: rdcu.be/eZ9n9
Progress and priorities in shark and ray fisheries management. The risk to species owing to incomplete management (‘M-Risk’, part a) can be described by 19 attributes across four classes for requiem sharks and guitarfishes.
Overfishing is compounded by under-management
Fishing mortality is the primary driver &
management completeness (for guitarfishes & requiem sharks) stands at ~49% globally.
@sammsherman27.bsky.social
@vanderwright.bsky.social
Read the paper here: rdcu.be/eZ9n9
Taxonomic differentiation of catch. FAO (United Nations Food and Agricultural Organization) on the percentage of catch reported to the species level worldwide.
What’s driving the decline?
The crisis isn’t just fishing — it’s invisible fishing.
Much shark & ray catch is under-reported, aggregated, or mislabeled, masking real mortality & delaying management.
What we don’t measure, we don’t manage.
@cgmull.bsky.social
@nathanpacoureau.bsky.social
Extinction risk and the spatial patterning of shark, ray and chimaera richness, including hotspots of coastal and deepwater richness, for wide-ranging and endemic species.
Sharks & rays are sentinels of ocean health.
- Global abundance has been fished down by 65%,
- Now 37.5% of species are threatened,
- The current extinction rate is 25–250 times greater than the background fossil record, with greatest losses in tropical coastal seas. #BiodiversityTargets
Bending back the biodiversity loss curve of sharks and rays. The loss of sharks and rays to date has involved serial depletion of the largest, most evolutionary and functionally distinct species, and the increasing prevalence of smaller-bodied species that have benefited from release from predation.
New paper out today in @natrevbiodiv.nature.com by the #GlobalSharkTrends team: Bending back the curve of shark & ray biodiversity loss;
Read the paper here: rdcu.be/eZ9n9
@sfu.ca
@sfubiosciences.bsky.social
@earth2ocean.bsky.social
🚨 New paper in Molecular Ecology Resources!
We compiled the most applied rapid DNA/eDNA-based ID tools & primers for #sharks and #rays 🦈
A practical guide to help scientists, managers & enforcement choose the right method for conservation action.
Read here: doi.org/10.1111/1755... #OpenScience #eDNA
✨ In collaboration with an incredible team of Brazilian researchers:
@ingridbunholi.bsky.social @patriciacharvet.bsky.social @rodrigodomingues.bsky.social @manirfeitosa.bsky.social + colleagues
Now published. Local reference data is essential for detecting species of interest such as these critically endanged sawfishes.
www.sciencedirect.com/science/arti...
Local genetic reference sequences can be essential for species specific studies. Applying what worked for a species elsewhere in the world (in this case largetooth sawfish, Pristis pristis) may not work where you are!!! www.biorxiv.org/content/10.1...
And here is the second one. Status change by the three main ocean habitats of sharks, rays and chimaeras through time.
@nickdulvy.bsky.social @nathanpacoureau.bsky.social @iucnshark.bsky.social @sscmarine.bsky.social
#sharkscience #shark #sharkconservation
Yesterday our new #globalsharktrends paper came out in @science.org
@nickdulvy.bsky.social did a great thread on the paper and included some GIFs that we had made but they did not play here on @bsky.app
I'm hoping this now works.
Status change through time...
science.org/doi/10.1126/...
🧪🐬🌎🦞🦑
Scalloped hammerhead sharks (Sphyrna lewini) IUCN Critically Endangered © Masayuki Agawa_Ocean Image Bank
New #GlobalSharkTrends study published in @science.org reveals #overfishing has more than halved shark & ray populations over the past 50-years causing widespread erosion of ecological function and exceptionally high extinction risk
👉Full article bit.ly/GlobalSharkTrends
🧵1/20
The beast is out!
@iucnshark.bsky.social has released a major new report: "The global status of sharks, rays, and chimaeras".
2100+ pages of information from over 350 authors from around the world.
Available for free download: portals.iucn.org/library/node...
#sharkscience
The IUCN SSC SSG was established to respond to growing awareness and concern of the severe impact of fisheries on shark, ray, and chimaera populations globally. The SSG is recognized as the leading authority on the status of these species, using science to support actions for conservation.
#WeAreSSC #SpeciesSurvival #ConservationPartners #SSCleaders #ConservationImpact #VolunteerNetwork #SSCPublications #ConservationWorks #shark #ray #chimaera #conservation #marine #science
Up-to-date assessments of the status of sharks, rays & chimaras from the IUCN SSC Shark Specialist Group.
#MarineEcology 🧪🌐🌍
This is such a fantastic resource amazingly led by Rima Jabado et al.! Happy to have played a very minor part as contributor to the chapter on São Tomé and Príncipe led by @gporrinos.bsky.social. Well done to the 353 contributors from over 110 countries! #OceanOptimism #Conservation
There are chapters for each major global region, and if you are a journalist writing about this report, we have experts from your region standing by to answer your questions. We also have a variety of high-quality images for journalists' use.
Cover of the new "global status of sharks, rays, and chimaeras" report
BREAKING: The IUCN Species Survival Commission Shark Specialist Group has released a new report on the global conservation status of sharks and their relatives.
portals.iucn.org/library/node...
Shifting baseline syndrome explains how we normalise the continual visceration of once unimaginably rich ecosystems.
Rewilding – our minds, lands, and seas – is the solution. 🌏
Let’s keep that increasing!🦈🦈
Made a Paleontology version of this a few years ago. Since we're all sharing...
