Kelp eating blues

Around this time of the year, when the bull kelp is really developed, I always notice that the intestines of the blue rock cod I'm cleaning is full of kelp.  Anyone know whether they're deriving nutriton from the kelp, or the critters living on it?

No answer to your question, but wanted to comment that I've seen several lings & cabs with kelp in their stomachs too.

once about 2 years ago, it was fall, i was freediving and resting at the surface near lovers point. i watched as some kelp rockfish were casually floating near some pinnacles and gulping the spongy algae stuff that looks like tennis balls on the sirface of the water in kelp beds.

it was funny, they would slowly drift towards it and gulp them up.

there were baitfish nearby so i dont understand why. maybe they do so to clean themselves out.

Maybe they need more fiber in their diet to keep them regular 

Come on people, were talking about rockfish... they'll eat anything.  Take a look at one of the most popular lures for them, the shrimp fly.  It's a white feather tied to a hook.  What is that supposed to imitate?

Blue rockfish are primarily plantivores.  Where they're small they eat little plankton like copepods.  When they get older they switch to larger plankton like salps and other small gelatinous jellies.  Occasionally if they're lucky they'll get a small shrimp or baitfish.  I imagine when you live your life sucking down jellyfish you might occasionally suck down a piece of kelp or two.  I actually asked a friend of mine who studied blue rockfish about this a couple years ago and he said that they probably derive some minor nutrient value from the kelp and seem to eat it more when their normal plankton diet is scarce.

Brian

Brian,

The feed species you mention, copepods, salps, and jellies, are all planktonic animals.  It seemed unusual to me that an animal adapted to eating other animals would switch over to algae consumption, especially considering the lower nutrient values found in kelp.  I was thinking that they actually consumed the kelp in order to digest the epifuana living on it, not the kelp itself.  It never looks well digested in the fish I clean.

Kelp grazing as opposed to predation seems like really different feeding strategies.  Sure is interesting, though.

i think rockfish prefer anything but my lures. also, if they do eat anything, why the heck do we bait with anything other than kelp? to keep some folks in business?

I'm guessing that the kelp that is eaten by blues isn't actually bitten off by the fish themselves.  Rather the kelp bits are simply broken off by other means (storms, waves, boats, seals, etc..) and are consumed by the rockfish as they float by. 

Has anyone actually seen a blue rockfish taking a bite out of a kelp frond?

As for why we buy lures to catch rockfish, well I guess becuase WE think they're pretty.  Most of the members on this board seem to consider blue rockfish a nusiance fish and the trick seems to be getting your lures down past the blue rockfish so that they can catch more desirable rockfish species.  Personnally, I have a blast with blue rockfish on light tackle.  Once you're in a school of blue rockfish it's really hard to find something they won't at least try biting.


Brian

I've posted about the fun to be had with blues on trout tackle, so I'm right with you there,Brian. The  2 to 3+ pounders I was catching at Elk were some of the funnest fishing I've experienced in a long time.

And you are so right about Blues hitting anything. I've caught more than one on a bare hook, and have heard talk of them being caught on an open snap.

And is it always about hunger? Fish investigate their world via their mouths. Maybe they're just curious about the funny things we throw at them?

Regards,
Scott

I consider it my fishing duty to take home a few blues and even a gopher or two, not just the trophy lings etc.

a fat blue has a lot of meat and I have been smoking them, but I'm sure they are good straight up.

they are definitely worth the light tackle hassle as they fight pretty well.  I only have medium tackle, but I loosen
the drag and use a barbless hook for these guys. some get off, that's okay.

it's worth using a bigger hook or bigger lure to weed out the dinks tho.

I thought a shrimp fly imitated a shrimp?

I have been using a saltwater fly as my teaser, it looks like a little grey and white baitfish, they love that thing. probably also looks like a small squid.

I think it is a lefty's deciever in the biggest size you can buy it, like 4" long and on a 4/0 hook. got it on ebay. check them out, search for salt water fly and deceiver. I crimped the barb on mine and I used it up at the swivel at the very top of my leader.

When I have fly fished fro ma baot in the Monterey Bay, we used 9-weight rods since we targeted Ling or White Sea Bass but caught plenty of Rockfish on  Deceivers, Clousers, Sur-mul-Macs, and other baitfish imitations. Olives, Blues, Blacks and the infrequent Vermillion, Cooper, Brown. We'd use a deep-sinking shooting head--just like I use for Stripers at the Forebay. Only we'd have anywhere from a 20 to a 50-sec countdown to get it deep enough depending where in the water column they were.

I keep saying I am going to try it in a kayak but didn't have the rod storage space on the Prowler. The Marauder has the storage for it and I am going to try it. Should be great fun--hitchhikers welcome, Mr. Ling