Mehis Rohtla

@NecoBus_8110 I would say that something in the range of 26-28 (depending on your interpretation of false annuli), but 22 is definitely too low.

【Challenge to age estimation】 Dear eel or otolith experts, How old do you think this Japanese eel is? Elver mark = 1 year-old. Welcome to retweet!

@RittwegTimo I will go with 12. Large vateritic section on ventral side?

...much better! Any aging experts want to have a guess at how old this venerable brackish monster was back in the day?

A pike mummy, caught in the 70s and "taxidermied" with formalin injections, marking the start of aging historic Baltic pike samples for a growth comparison with recent fish and using stable isotopes to look for diet shifts from the 70s til today. Excited to dig into the past! 😁

@FishSecretariat @balticseacentre Okay, I already read that there are exceptions for glass eels 😏

@FishSecretariat @balticseacentre If true that the closure also includes glass eel fishing then I would not be that critical about this Council decision - most glass eels arrive to Western-Europe within this closure period. Also September-October is the main escapement period for silver eels in many regions.

Swedish @balticseacentre adds to critical voices on #AGRIFISH agreement on #European_eel earlier this week: su.se/stockholm-univ…

@RArlinghausFish @Chikichanka @WillemXDekker @EdmondshamLand @EelGroup @ices Show me the evidence that it is good for eel 🙂. Good for eel fishing, yes. There are several examples why restocking might be bad for eels. But there is a difference where/how you do it - eg it is probably ok with wild recruits within the same river system they arrive to.

@Mehka71 @Chikichanka @WillemXDekker @EdmondshamLand @EelGroup @ices Careful. This is plain moral arguments and a new topic (stocking). Stocking in closed lakes is nonsense. Spreading fish through stocking in rivers may spread risks and be a buffer. Show me the evidence this is bad per se? (Clearly migration must be possible and harvest moderate).

@RArlinghausFish @Chikichanka @WillemXDekker @EdmondshamLand @EelGroup @ices I also disagree. It is morally wrong to justify yellow/silver eel fishing in those inland lakes/rivers just for the sake of the traditions. And especially if those eels are restocked as is the current practice in Estonia. Let them fish for some eels there where there are wild eel

@Chikichanka @WillemXDekker @EdmondshamLand @EelGroup @ices The current assessment does not cover coastal abundances well and there is no evidence that fishing is strongl affecting the stock/species. Again, you may take the precautionary approach but it comes at economic extinction of the last few inland commercial fisheries.

@RArlinghausFish @Chikichanka @WillemXDekker @EdmondshamLand @EelGroup @ices Let those small-scale fishers fish for eel as long there are eels there (up to 10 years perhaps). There is no proof that we are doing good to eels with restocking over long distances. Just traditions. Once was slavery and whaling also widely accepted...

@Chikichanka @WillemXDekker @EdmondshamLand @EelGroup @ices No. Banning fishing is necessary only if the activity is impacting strongly on the stock. The handful of small-scale German inland fisheries are however not having an influence, while being jobless overnight in case of a ban.

@RArlinghausFish @Chikichanka @WillemXDekker @EdmondshamLand @EelGroup @ices Ban most glass eel fishing (and eel farming which is definetely nonsense and should be stopped), use a small number of glass eel fishers in rivers which get a surplus of glass eels (if there are any) to restock nearby rivers (and not bring them to e.g. the Baltic Sea for now).

@RittwegTimo I feel you, had the same experience in other parts of Chile 😏

Navigating la Ruta Sur in Patagonia in a nutshell 😬

@RittwegTimo Lets do it 💪

Followed by a great talk by @Mehka71 on long-term data on pike describing origin of anadromous, freshwater and brackish pike in Estonia. Strong contrast to what's happening in German Baltic! 🤔 Is it time to join forces and look at Baltic-wide patterns (*winkwink)? #IOS2023

Brilliant keynote by John Mortongiello on challenges and future prospects of otolith growth chronologies at #IOS2023

@marty_hamel 21 or 22. More likely the latter.

Here is a known-age Largemouth Bass from our known-age fish project. What is your estimate? #otolith #fisheries

@RArlinghausFish @RittwegTimo Is the talk accessible somehow?

@RittwegTimo gave a great talk today on pike growth.

@otolithgirl @OMorissette #OtoliThursday for me too after a long time 😏

Ahhh otoliths. First prep I've done in years after becoming such a desk scientist. It's so meditative 🥰 Ooh and it's #OtoliThursday too! (is that the right hashtag @OMorissette?!) PS. Anyone want to guess the species?

@TrevorABranch R coding

Folks who are in grad school or working in ecological science, what quantitative skills do you wish had been offered in undergrad? (e.g. coding, t-tests, regression, random forests, resampling analysis, etc.)

@RittwegTimo 5.6 cm is no problem for a 3 kg ide? But yeah, a tough one...

@Mehka71 I've just realized it's always clever to include a scale in such pictures. Those are pretty large, 5,6 cm in length. If cyprinid, that must've been a big one! 😅

Cramming through an ancient drawer in my (home-) office and found these two. No idea what species this was. Any ageing folks around who can help my memory? (I'd say age is around 7+, whatever fish it was... 😅)

@RittwegTimo Cool! However, maternal signal should reach ca 100-150 microns from the core in my experience (but it could be more in your "pike on steroids" 😁, 40 cm in the first year = 🤯, this is world record growth?).

@Mehka71 Oh, right, I forgot about this...🤪 Here the corroborated age. Some noise in the core (likely maternal signal) and the first year isn´t super clear, but there is a peak associated with a visual annulus. The rest is nice and clear, so this fish was corroborated as 10+😉👍

Working a bit on my cutting, embedding & polishing techniques. 1st pic: Before; 2nd pic: After. Getting somewhere! 😁 Any ageing pros around? How old do you estimate this fish (It´s a pike btw, but I won´t tell the size, that´d be to easy 😉)?

@RittwegTimo Updates? 😉

@Mehka71 I estimated 10 (white small marks = hatch & exofeeding check), but we´ll know for (relatively) certain once I processed the isotope profiles for this one. I´ll be sure to post an update then! 😉

@HellstromKGV @svt Hvis vi kunne... Programmet kan bara ses i Sverige...

Check out the new excellent documentary series about fish by @svt Our research on wels #catfish and Bluefin #tuna is highlighted svtplay.se/fiskarnas-rike svtplay.se/video/32916003…