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coho diet oddity

PostPosted: Mon Sep 03, 2012 6:33 am
by Smalma
Nelly -
Know that you enjoy looking to see what the salmon have been eating and in that process have found some interesting prey items. Last week during a two day trip to Willapa Bay I ran into a first for me. In the process of looking for a Chinook we managed to stumble into 3 coho.

The only food items in all three coho stomachs were dungeness crab megalopae. The megalopae were decent size - two would cover your little finger nail. Two of the fish (including the larger one) were stuffed with the crab larvae - the contents from an individual stomach would nearly fill a cup mug. The third fish's stomach was about 1/2 full.

The flesh of all three were much "redder" than normal with the middle size fish cutting as red as any of the Baker sockeye we caught this year.

BT
The large one was in the upper teens - it was weird seeing so many small food items in the stomach of such a large fish. Have to wonder why the fish decided to take our herring.

Curt

Re: coho diet oddity

PostPosted: Mon Sep 03, 2012 9:13 am
by Nelly
It's always great to wake up (I slept in today yawn ...), look at the board and see a thought-provoking post from the "House Biologist!"

I have also been fascinated by the variety and quantity of food items found in Puget Sound coho this season but my "findings" might be skewed by this season's sample size!
To date -and I haven't wet a line in September- nearly twenty coho have graced the fishbox, each and every one with a different meal plan!

Talk about opportunistic feeders... Squid, euphasid shrimp, smelt, chinook smolt, pink (or humpy) fry and yes, herring have all popped out on the coho on my cleaning table!

Now Smalma, I've got a question for you: After a summer of chinook plugged with candlefish, have you ever observed coho feeding on this food item? If so, wouldn't this indicate bottom or deeper water foraging coho? :ugeek:

Re: coho diet oddity

PostPosted: Mon Sep 03, 2012 3:37 pm
by Smalma
Nelly -
Resident and sub-adult coho (shortly after entering the salt) feed pretty heavily on juvenile sand lance in the late spring/early summer. Those small sand lance are typically found along the beaches and are easy pickings. It probably fair to say the for the majority of the coho their first fish meal are sand lance. As they grow larger (say 19 or 20 inches) herring the prey of choice.

Also see the odd sand lance on beach running coho as they return from the ocean into the sound. Can not say that I have seen significant sand lance numbers in the stomachs of coho caught over deep water here in the sound though to be fair most of the time we encounter such fish here in the Sound they are no longer feeding.

You can add anchovies to the list of food items found more or less regularly in coho stomachs.

Curt

Re: coho diet oddity

PostPosted: Mon Sep 03, 2012 8:54 pm
by Medium D
One thing I have noticed and mentioned to Robbo... The kings on the Nisqually and the Coho on the Puyallup are all cutting extremely red. I can't remember the last time these Nisqually fish cut this nice. In the past, you would retain a fish in decent shape. I say decent, as it's a well known fact that these Nisqually Puget Sound nooks, turn early.
Not the case this year and that goes for both bucks and hens.
Could it be a large consumption of krill in the ocean and or other shrimp as well? I had heard some reports that indicated a much higher than normal amount of Krill, in certain parts of the ocean...

Thoughts..

Medium D.

Re: coho diet oddity

PostPosted: Tue Sep 04, 2012 6:04 am
by Smalma
Medium D -
Not sure that anyone knows what those fish have been eating but something that I have noticed is that on the whole the condition of our Chinook this year has been exceptional. Whether here in the Sound, at Buoy 10 on the Columbia or Willapa Bay (as well as the pictures of fish I have seen from other locations) the Chinook at least to my eye seem to be chunkier than normal - a fish that I would expect to weight in the mid-teens have been a pound or two heavier than I expected based on their length.

Typically salmonids that have encounter exceptional feeding oportunites really pack on the weight resulting in "fatties". I suspect that our Chinook found very good forage(whether sand lance, herring, shrimp, etc) the last few months of their growing season giving them that robust condition and high fat content. The result is that even though the river fish are in a downward slide in regards to condition (fat being converted to gonadal development and stay alive) they are in relatively good shape because they started at a higher level.

What you are seeing is what we may see with spring Chinook where even in the Snake they cut really well. That is not to say they are as prime as they were at Portland - they are not!

Nelly or Robbo with their wider experiences may have some additional thoughts or insights in what the fish's diet may have been off the coast.

Curt

Re: coho diet oddity

PostPosted: Tue Sep 04, 2012 3:21 pm
by Moosestock
One thing I noticed in the extremely good hatchery King run at Port Angeles this year was that that first run of fish I caught in early July were just chalk full of small 2 to 3 inch squid. I haven't seen anything like this in the past other then some digested part that looked squidlike. Those fish were just "Footballs". I have seen some sites that center on Tuna fishing saying that their were small squid in their stomachs also. It makes it look like there was an extemely big lot of squid in the ocean this year and that would also drasticly help the food chain..................Les

Re: coho diet oddity

PostPosted: Thu Sep 27, 2012 3:44 am
by Nelly
This year's coho run is just spectacular and whatever.they are eating, I hope they keep on doin it!
I don't remember silvers tasting as good as they do this season.
We put one on the BBQ last night and the oil coming off of it reminded me of a springer!

Re: coho diet oddity

PostPosted: Thu Sep 27, 2012 5:38 am
by LndShrk
We too have found some crab larvae in a couple of coho this year. Out of all the coho I have cleaned this year (a few wave ) I have only gotten one with herring in it. Mostly it has been Candle fish shrimp even some full size spot prawns. Allot of them have also been empty. Typically I see allot more herring.