1
Hookups and Fishing Reports (Viewable by Public) / Re: Rockfish Closures are coming
« on: September 03, 2023, 09:21:31 PM »
This is the heart of the matter, to me. I read through the document and my read was that they lack sufficient data on Quillback survival after release, so they assumed mortality equivalent to other demersal (bottom-dwelling) rockfish. I think most of us here would agree that is unsound, as Quillbacks appear to suffer less barotrauma than any rockfish other than Blues, and certainly are not comparable to, say, Gophers.
As to descenders, I asked James Phillips about that, and his response was basically that Oregon and Washington indicated poor compliance. The law says you must have one on board, so boaters carry them but won't use them. I didn't get any more information or data from him about that so I don't know if it is based on published research or anecdote.
The final aspect of this that bothers me is, the commercial fishery is not affected. The inshore stick-riggers can still fill their live-fish tanks for the Asian markets. And they like Quillbacks because they look pretty.
Tim
As to descenders, I asked James Phillips about that, and his response was basically that Oregon and Washington indicated poor compliance. The law says you must have one on board, so boaters carry them but won't use them. I didn't get any more information or data from him about that so I don't know if it is based on published research or anecdote.
The final aspect of this that bothers me is, the commercial fishery is not affected. The inshore stick-riggers can still fill their live-fish tanks for the Asian markets. And they like Quillbacks because they look pretty.
Tim
Clayman, you're thinking in the right direction.I think descending devices didn't become common until the last few decades, and the recreational discard mortality rates used by CDFW in this report don't jive with the science of the last two decades. It was Table 4 in the report I linked. I'm including the table at the bottom of this post.
A couple things you might consider. The model considers something they call "discards" but isn't obvious about whether they consider those 100% mortality or not. I believe they attribute a percentage (maybe 50%) survive.
As to whether the quillbacks you return from 180' make it because you don't see any barotrauma... I would say be cautious about that. I don't know how well quillbacks float, but they did quite a bit of research on survival rates. According to their data a very high percent of fish from 60'+ die. Thats part of why the commercial guys think descenders make no sense. From their perspective any fish brought up from 200' feet is not going to make it, descended or not...
You're on the right track, though. How do we reduce quillback mortality and still fish?
There are many studies on rockfish barotrauma and survivability when descended back to depth. Here's one that documented 100% survivability of descended quillback rockfish when caught up to 64 meters (210 feet) in depth: https://www.tandfonline.com/doi/full/10.1080/19425120.2012.655849
Alaska, Oregon, and Washington all require the use of descending devices when rockfishing. I don't know why California hasn't followed suit. The science seems pretty clear that descending devices work.
My personal observations are purely anecdotal. I know they don't mean anything from a statistical standpoint. Just sayin, I've never had a quillie blow up on me.