Yep, I remember.  If it is the one I'm thinking of it was at the FADs early last year.  Nice fish - it is in the collection.

I knew it - straight away, and I'm out of my depth! LOL.  I know snippets about life-history and fisheries biology, but that's not my field.  However, I do know that growth rates for Herring are well known.  I also know the rates differ slightly in different parts of the coast, although genetically they are all part of the same population.  They reach maturity at about 2 years old when they are around 20cm.  I'm guessing similar data are available for Skippy too - I'll have to pass the buck to Dept. Fisheries, or Google.

Good point.  We (the museum) don't have any sharks from the Peel, or records that are certain, but I do know of many anecdotal reports - most probably Bullies.  I can't see much of a reason why they shouldn't be there.  As to why they are not seen often, I'd be guessing.  But then again, they are not really seen that often in the Swan - it's just that the media likes to make something out of when they are.

I enjoyed the show last night.

edit: you got me thinking about a report I had in the back of my head and with a bit of googling, I found this

http://www.fish.wa.gov.au/docs/media/index.php?9999&mr=107

ha, we get this one a lot!  All approximates of course...

World ~32,000 but more undescribed ones

Australia ~ 4,500 but probably closer to 5,000

WA probably somewhere between 3,000 and 3,300 depending on which islands you call 'WA'

Given the research you seem to have done, you probably know as much as me, or anyone for that matter.  The answer is - we still don't know.  For those who are interested, the Longtail Survey has a webpage (http://www.longtailtuna.com.au/) and the final FRDC report on longtails is available and on page 18 there is a summary of the status:

6.2 Stock structure

There has been debate regarding the stock structure of longtail tuna throughout the Indo-Pacific region. Abdulhaleem (1989) found significant differences in the number of gill rakers in fish between Oman and India and suggests that this may be indicative of at least two separate stocks in the Indian Ocean. Serventy (1956) also suggested that separate stocks, and possibly even two sub-species, may exist in Australian waters based on the distinct difference in the size distributions of fish off the eastern, northern and western coasts of Australian. Wilson (1981) tested this hypothesis by using morphome rics and allozyme electrophoresis and found no differences between samples collected from Papua New Guinea, Gulf of Carpentaria, Moreton Bay (Qld) and Shark Bay (W.A.). However, he warned that his results need to be viewed with caution owing to small sample sizes from the latter three locations.

It is clear from length-frequency data reported in studies throughout the distribution of longtail tuna, that there is an obvious increase in fish size with increasing latitude. This appears to be most apparent in Australian waters, where several studies (Serventy, 1942a;1956; Wilson, 1981; Stevens and Davenport, 1991) have shown fish to be smallest in the Arafura Sea in northern Australia and gradually increasing in size with increasing latitude southward along both the east and west coasts. Very few small fish less than 40 cm fork length (FL) have been recorded from Australian waters, while fish of this size are abundant in southeast Asia and support large commercial fisheries. This suggests that there may be a southward ontogenetic migration from a more northern nursery ground, such as Thailand and Malaysia (see Yesaki, 1993). As a result, longtail tuna may exist as a single stock throughout southeastern Asia and Australia. However, considering the significant geographic barriers evident throughout the neritic distribution of the species, the possibility of separate stocks of longtail tuna being present throughout its geographical range cannot be discounted. In the absence of tagging data and reliable genetic analyses (i.e. using DNA), the extent of mixing of fish between countries or water masses remains unknown.

(from: http://www.frdc.com.au/documentlibrary/finalreports/2008-058-DLD.pdf)

This is very interesting.  I remember when you posted it and was puzzled then - forgot to follow it up.  Leave it with me and I'll get back to you.  I have some ideas that I need to follow up.  Can you tell me if you filleted it, what colour was the flesh?  (you need to take better photos - ha!)

Maritime and Shipwrecks are both part of the WA Museum, but nothing to do with me, I'm afraid.  They fall under Maritime Archaeology.