SML Striper Growth

[striperjohn]

Man! Take a few days off from reading this post and you miss a lot! Now that I've read it I've figured out a few things;
1. We need to let Dan do his thing and offer help as we can.
2. This is confusing as heck.
3. I'm extremely glad to see so much interest.
4. I need a beer, and a headache pill, and a couple more beers.
5. Mike we could of had this conversation at the Meet N Greet, about 9-930 it would of really been good to hear!
Cheers,
John

[mwardncsu]

Received some updated info from Dan now that he had a chance to complete processing of the fish-heads he had from 2013.


Commentary from Dan:

I finished up with the remaining otoliths that I had and it did change the table some. There were a good number of older fish in this group which I did not have many of before. Most of the ages/growth stayed about the same but the growth improved some for ages over 7 but not enough to say things are fine. As you can see by Largest and Smallest fish in each age, there is a lot of variability in growth so some fish are growing fairly well while others (most) are being left behind. Variation in a natural population is normal but this much is not and most are stuck on the slow growth train.

Year		Average			# of Fish
Stocked	Age	Length	Smallest	Largest	Sampled
2011	2	19.8	18.2	21.0	13
2010	3	22.8	20	25.0	34
2009	4	25.1	23	27.0	12
2008	5	26.5	23.5	28.7	27
2007	6	28.0	25	31.0	24
2006	7	29.1	24.5	33.5	38
2005	8	29.4	27	34.5	15
2004	9	29.0	26	32	6
2003	10	30.5	28.7	35.7	7
2002	11	31.9	28	35.5	10

Also, data on catch rates / citations.... keeping in mind the catch rates & % of catch >30" comes from angler diaries...... 29 in 2013.... (up from 23 the previous few years)

	Angler CPUE	% of Catch > 30”	Citations
Goal →	≤ 3.7 hrs/fish	30%	150
1998	3.6	17%	170
2003	5.0	10%	21
2004	3.3	2%	7
2005	3.4	8%	25
2006	3.8	10%	23
2007	5.0	13%	38
2008	3.6	19%	45
2009	3.5	18%	42
2010	5.2	16%	90
2011	3.4	18%	63
2012	2.9	13%	44
2013	3.6	12%	32

[mwardncsu]

Updated the post above to include the # of diaries turned in during 2013.... 29 - have only been getting 25 +/- a couple since 2005..... Such a simple thing to do that can have a beneficial impact on the management of our fishery - keep a diary and turn them in!

[BentRod]

Citations have fallen way off. 1/3 of what it was in 2010.

Mward dropped a thought out there yesterday that makes more sense to me than anything I've seen yet. They increased the stocking numbers in 98 after the striper club pushed for it and the fishery was in decline from 98 until 2003 when it crashed and a lot of fish were taken out of the system. Is it not possible that from 03/04 to 2010, our population of fish was in check because of all the fish we lost in the kill, and then in the past few years, our overstocking has again caught up with us and we're flatlining again? To me, that's the most logical reason I've heard.

[Deleted]

MWard..are these citations from diaries? If so..can you divide the citations by the number of diaries submitted? Secondly, is this citation data real citations (certs) or fish submitted over 36 inches?

If not can we see fish over 36 for the periods normalized by percentages?

Thanks in advance. This 2013 data looks like what I expected to see while playing with the numbers.

[mwardncsu]

There are two bits of info combined in that last table - I think Dan shows it that was as it ties back to angling goals set some time back (catch rate, % over 30" and # citations). Citation info comes from submitted citation applications to DGIF - fish >= 37" OR >= 20 lbs (in a certified scale). Has nothing to do with diaries.

Not sure what dividing citations by diaries does

I've personally never put a lot of stock in citation data as it is dependent if folks to submit them - and pay the citation application fee, etc. I know numerous "citations" that go unfiled. My feeling is this is a variable number - folks mail in their first one or few then don't. Maybe I'm wrong there or maybe it's a consistent enough pattern of behavior that it's still a decent trend indicator - I'm just not real confident in it - but it is another bit of data in an environment of limited data I guess.

[piper]

Feb 21, 2014 7:02:19 GMT -5 BentRod said:

Citations have fallen way off. 1/3 of what it was in 2010.

Mward dropped a thought out there yesterday that makes more sense to me than anything I've seen yet. They increased the stocking numbers in 98 after the striper club pushed for it and the fishery was in decline from 98 until 2003 when it crashed and a lot of fish were taken out of the system. Is it not possible that from 03/04 to 2010, our population of fish was in check because of all the fish we lost in the kill, and then in the past few years, our overstocking has again caught up with us and we're flatlining again? To me, that's the most logical reason I've heard.

I think 2010 has to be a skewed number on some level. Im not a statistics guru but you would almost have to eliminate that year from most discussions as it seems to be an outlier and not consistent with years before or after.  So to answer..Id have to say no .  Even look at this "# of fish studied" info. Those numbers of 34 in 2010 drop to 13 in 2011.; That in itself is off.  Again Id eliminate that 2010 from the discussion points and look at those before and after as a more relevant reflection

[Deleted]

I edited my last post. You are too fast man!

If the citations were from fishermen then dividing by number normalizes the data. Example...5 people caught 5 citations is better than 50 people caught 25 citations.

I don't buy the citation data either...but I would buy number fish over 36 from fishermen data.

[mwardncsu]

Piper - the "number of fish studied" # of fish is of a given age. All those fish heads were harvested in 2013 and aged using the oolith bone. Of the fish submitted, X were from the 2011 class, Y from the 2010 class, etc. So more being from 2010 in that data just means that many 3 year old fish were caught and submitted.

Since there was not any gill net collections in 2013 all data is from fish heads. About mid-year Dan requested not to submit heads from fish less than about 26" as he had plenty of data points on the small / younger fish.


Yam - gotcha.....

[Deleted]

If 2014 data shows yet another decrease in fish caught over 30. Then not only will this show that Dan acted ahead of the storm, it will provide him the fuel to tweak again. As Bentrod mentioned..these are just minor tweaks.

I am dying to know if this is overpopulation, not enough bait or the effects of the copepod. The scary thing about biology is that it could be from an over population of stink bugs.

[BentRod]

Citation data is just another small piece of information that shows the same trends as everything else. Certainly citation data is no where near accurate, but I'd say its reasonable to think a similar percentage of people report year to year, although no way of knowing for sure.

[Deleted]

So can we isolate over 36 inch fish from fishermen data? This would be interesting to compare to citation data.

[BentRod]

Not unless you have the raw data from the past 12yrs to do it. Ask Dan.

[Gator]

Feb 21, 2014 9:29:16 GMT -5 Yam said:

So can we isolate over 36 inch fish from fishermen data? This would be interesting to compare to citation data.

Yam, I am sure that the data could be isolated. Problem I see is that we do not have enough fishermen participating with the collection of data. Dan seems to be doing everything that he can with the resources available to him. We need to partner with DGIF and do whatever we can in the data collection process i.e diaries, fish head samples, volunteer work, etc. lets all be proactive on this. Just my .02 cents.

[Deleted]

Feb 21, 2014 10:11:29 GMT -5 BentRod said:

Not unless you have the raw data from the past 12yrs to do it. Ask Dan.

I wouldn't want to waste his time. I'm just interested to see if fisherman data showed the same spike that citation data did. This would mean nothing to the bottom line. The trends all point the same way.

Of course, a simple yet elegant little information system could make a report such as this as quick as a button click!  

I'm with you Gator and plan to do my part as accurately as possible!