Potential Tuna Research

[Stoisy]

Hey all,

Going to be spending the fall in Bamfield at the Marine Science Centre doing some school. Part of the program is to complete a research project from Sept to December. I haven't finalized any details of the project yet but initial thoughts are to do something with diet, age, or.....? I am just wanting to contact some of the locals in Bamfield to ask if you guys have any nagging questions about the Albacore that you would like answered? I have access to the lab in Bamfield and would likely need samples (carcasses) if anyone would be willing to share... I guess I just want to get the discussion started and see if there is something I could help answer in my time there.

I have worked as a salmon guide for the last 8 years between HG and Vancouver and will have Sundays off from the program...so if anyone needs a hand on deck as well I would be more than happy to bring along a few cold ones! (or whatever you require for payment!)

Cheers,
Steve

 

[tykkyt e blue]

One thing I would like to know is how much squid vs bait fish our local tuna eat? ( some days white seems to be a favoured lure color and other days not so much? )I'm moored in Grappler just around the corner...wouldnt be harder to sort something out

 

[Seagirt]

Do you know what types of equipment you'll have to use and what the possible questions are that you'll be able to answer? Laser oblation mass spechtrometry, micro chemistry detection, or the myriad of things we are able to do now? Are there any current or past studies that you can build on? 4 months is a short window... Stomach contents would be interesting to quantify and for the guys that gut their fish before icing it may be easy enough to convince them to put aside the stomachs for you. This assumes that tuna keep their gut contents while being caught and don't digest their prey too quickly. 3 months of keying out vertebrae of small pelagic species sounds like character building!

Interesting thread, I hope people put forth their questions.

 

[tykkyt e blue]

Another thing...there is often discussion about who has the 'correct' temperature among the boats working together. I bet you could get a deckhand ride for just borrowing the labs most accurate water thermometer and help us group calibrate our boats temp gauges so they all read the same accurate value.

I took a MSC student out last year during the derby bec he studied pelagic seabirds and hadn't actually seen one all summer - he musta taken a 1000 photos! Once we got far enough offshore and the birds were around...it was like having a 9 yo kid in the boat on Xmas morning ha.
He did share with me how those birds find baitfish so far from land ( acute sense of smell about some protein molecule that baitfish emit ) and that helped me understand how to use bird behavior to find tuna - So I'm willing to help another student

 

[Dogbreath]

....3 months of keying out vertebrae of small pelagic species sounds like character building!

^ science geek humour.

 

[Seagirt]

Confirming key prey species will help with management of those small pelagic species also. I'm unfamiliar with how (or if) those small species are managed but knowing their worth as prey of the tuna could help drive decisions. And the warm water phenomena that is occurring out there right now could be introducing smaller, less notable, species that would only be discovered with the help of the tuna acting as collectors. Environmental DNA analysis of waters near where tuna are concentrated is another method possible for detection of species present.

 

[Birdsnest]

I've noticed what seems to be a parasite or Parisite like formations on many tuna. It is yelowish orange and found on the gills and under the skin. I'd like to know what that is.
it seems that if you see it in the gills it will be under the skin. Under the skin it appears to be an inverted bubble of orangey fluid never larger than half a small pea.
When processing I just scrape it off and forget about it. It seems to be more prevalent some years than others and on larger fish.

 

[Birdsnest]

It would be cool to tag a local tuna and see what they do in a day in terms of depth, spreed and location.

I suspect a lot of these questions have been answered already.

 

[Stoisy]

Thanks guys! Keep the ideas coming!

 

[Seagirt]

Plastic in the digestive track or tuna, or more likely in the digestive system of their prey?

Make any decisions yet?

 

[nicnat]

it would be interesting to see what the mercury content would be, if any. after reading a report a while back in consumer reports mag it was showing fairly high levels in canned albacore tuna. I assume that is probably longline caught commercial tuna.

 

[agentaqua]

it would be interesting to see what the mercury content would be, if any. after reading a report a while back in consumer reports mag it was showing fairly high levels in canned albacore tuna. I assume that is probably longline caught commercial tuna.

Some Tuna Can Carry Up To 36 Times The Toxic Chemicals Of Others. Here's Why
By editor • Aug 9, 2017
http://kazu.org/post/some-tuna-can-carry-36-times-toxins-others-heres-why#stream/0
https://ehp.niehs.nih.gov/EHP518/

 

[gamechanger]

if we get some tuna in the derby you could likely get some samples, get in touch with Jerry at Mills Landing, or Brian McKay and McKay Bay, I'm sure guys would be happy to give you the carks.

 

[skagittarius]

I've always wanted to know more granular information about Albacore depth distribution. I know they are an epipelagic and mesopelagic species, but that's a large range and I've read the Pacific species feeds as deep as 400 meters. What I'd really like to know is the time a fish spends in, say 25 meter increments. There's been a lot of speculation this summer regarding fish staying deeper than normal presumably due to an abundance of prey at those depths, but it would be interesting to see if that is really the case and how much that typically fluctuates during a migration cycle or two. Not sure if we have the tag technology that allows us to record that info, but I think it would be extremely useful. I know I'd feel a lot better if I had saw data that, for example, indicated at any given point of time the commercial troll fleet is only able to access say, 20% of the fish that are out there based on average depth distribution.

 

[Seagirt]

Those are interesting questions, but this thread is two years old.

 

[agentaqua]

I've always wanted to know more granular information about Albacore depth distribution. I know they are an epipelagic and mesopelagic species, but that's a large range and I've read the Pacific species feeds as deep as 400 meters. What I'd really like to know is the time a fish spends in, say 25 meter increments....

Looks like the references say that the peak for albacore happens at~200m - but actual depths are determined more by oxygen levels (have to better than 2.0 ml/L) - with the larger albacore found at greater depths in the water column - as the smaller ones have higher oxygen demand.