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Fish Mortality/Gear Type Study

Posted by Mark Wednesday, December 28, 2011

Here's a little meat to chew on from an actual study. Now you can start to extrapolate some numbers from this to see what kind of damage is being done to wild fish in the Umpqua drainage as well as many other systems throughout the NW. The days of excess are over people, we need to take a LONG look at how were are managing these fisheries or they will be distant memory. 

Makes me really think about taking wild fish out of the water, even for a few seconds. I always try to get fish in as quick as possible, and do my best to keep the fish I catch in the water.Sure, I admit I have taken pictures of fish out of the water and I am not perfect in this regard but I will make it a point in 2012 to do better.

Maybe Oregon should start regulations similar to Washington that make it unlawful to hold a fish out of the water. I would be all for it.This is a law that only makes sense in a Wild C&R fishery. Handling of the fish and the associated mortality rates would go way down, a good thing and an idea whose time may have come.

From Bill Bakkes Home Waters and Wild Fish site comes this interesting article. A good one to follow close on the heels of my recent post The Choice. Note the parts about repeated hooking and fish out of water/air  exposure and related mortality rates.

In my opinion,and for the more local discussion on the Umpqua drainage, bait would be actual bait(eggs,shrimp,sardines etc) as well as simulated bait including yarn balls,glo bugs corkies etc. which are often enhanced with oils or liquids that give off scent. These methods would all qualify as  "angling with bait generally results in substantially higher catch rates and mortality rates for both target and non-target fish than angling with any other gear type" as noted below.


Here is a another interesting article on single barb-less hooks from Bill's site.


Click on paper below to view the entire thing.


WILD STEELHEAD MORTALITY AND GEAR TYPE


In 2001 Bob Hooton, fish biologist for the British Columbia Ministry of Environment, evaluated the impact of bait, lures and flies on steelhead and resident fish. This paper reviews what is known through scientific evaluation of relative impacts of these fishing types.  I have provided a few interesting quotes form this paper below.
“During the Keogh River experiment, it quickly became evident that, in order to obtain the requisite sample size of steelhead hooked on artificial lures, it was necessary to commence angling sessions with that gear type.  Despite a strong bias towards artificial lure fishing prior to using bait, lures caught 99 fish while bait produced 236 or 2.38 times as many for similar hours fished.  Additionally artificial lures caught fish were hooked deep inside the mouth or gill arches and bleeding heavily in 4 of 99 cases (4.04%).  Bait caught fish were similarly hooked in 26 of 236 records (11.02%) or 2.72 times as often.”
“During the Keogh hooking mortality study discussed earlier a total of 130 and 206 
steelhead were angled in study years 1985 and 1986 respectively (Hooton, 1987). The
weir count of adult steelhead over the period that angling occurred downstream from the
fence was used to provide a reasonable approximation of the percentage of the run
captured in the time allocated. In 1985, the data revealed that project staff fished 117
hours to catch 130 steelhead that represented about 27% of the fish available. In 1986,
121 hours were angled to catch 206 fish that represented about 19% of the supply. In
other words two anglers fishing an average of one hour per day over a two month period
caught roughly one quarter of the population one year and one fifth the next. All of that
occurred in about 50 meters (164 feet) of river.”
“More recently Keogh project technicians involved in requisite sampling of steelhead
upstream from an electronic counter captured 45%, 62% and 30% of the total available
supply of steelhead in 1998, 1999 and 2000 respectively. For 2001 to date the figure
stands at 51% (personal communication, Bruce Ward, Senior Anadromous Biologist,
Ministry of Agriculture, Food and Fisheries, University of BC, Vancouver). These catch
rates resulted from two staff fishing for an hour or two per day over several kilometers of
a river that is not held to be particularly accessible or “fishable” by most steelhead
anglers. All of the fish were angled with bait.”
“What we can say, however, is that angling with baited hooks is prevalent in streams
where it is legal, that angling with bait generally results in substantially higher catch rates
and mortality rates for both target and non-target fish than angling with any other gear
type, that many of the wild steelhead stocks subjected to this combination of factors are
far below target escapement and that the status of non-target stocks and/or species is
frequently as bad or worse than steelhead.”
Catch and release may have been oversold in that there tends to be a pervasive opinion it can be prosecuted limitlessly with no influence on the status or health of steelhead or sympatric species. With respect to fluvial resident trout populations it was accepted long ago fish are too catchable and prone to hooking mortality to sustain fishing with certain gear types. Resident fish are simply that – stationary inhabitants of the available habitat. Arguably, steelhead in most of British Columbia’s short coastal streams, are effectively resident trout. Their vulnerability is entirely comparable to fluvial resident trout.”
Rearing juvenile steelhead and resident fish are affected by gear type:
“With respect to fluvial resident trout populations it was accepted long ago fish are too catchable and prone to hooking mortality to sustain fishing with certain gear types. Resident fish are simply that – stationary inhabitants of the available habitat. Arguably, steelhead in most of British Columbia’s short coastal streams, are effectively resident trout. Their vulnerability is entirely comparable to fluvial resident trout.”
““Bruesewitz (1995, WDFW) examined the location of hooking among creeled summer and winter steelhead in different Washington State streams in the 1992, 1993 and 1994 sport fisheries. She found that the single hook and bait combination resulted in a 2.33 times higher incidence of hooking in critical locations (14.9% versus 6.4%) than did single hooks and artificial lures.”
Exposure to air and mortality rate:
“Ferguson and Tufts (1993) reported disturbingly higher mortality among domestic
rainbow trout subjected to air exposure after mimicked angling events than for control
fish or experimental fish not exposed to air. Their data revealed 100% survival among
control fish and 88% survival among exercised (i.e., “angled”) fish. Among fish that were
exercised and then exposed to air for 30 and 60 seconds immediately thereafter,
survival dropped to 62% and 28% respectively. The authors stressed their results had
important implications for Atlantic salmon sport fisheries where the marked trend was
toward catch and release but where anglers habitually hold fish out of water for
significant periods of time prior to release.
Influence of multiple captures on fish mortality:
The influence of multiple captures of individual steelhead is another element of many
British Columbia steelhead fisheries that remains to be evaluated. Catch and tag
recovery data from a large number and range of Ministry programs indicate that in many
heavily fished streams steelhead are commonly caught two or more times. It is
reasonable to conclude the frequency of these occurrences has increased steadily over
the past two decades. The emerging and unanswered questions are whether or not
there are cumulative effects associated with multiple captures and how significant these
are from a population perspective? It is clear from the available CPUE (and mortality
rate) data presented above, however, that any risk of sub-lethal effects associated with
multiple captures would be skewed markedly toward gear types and procedures that
increased an individual fish’s frequency of exposure to those circumstances.”
Hatchery fish increase angling pressure and wild steelhead mortality
“Close examination of Steelhead Harvest Analysis (SHA) data reveals a consistent pattern on streams where hatchery steelhead have been introduced. The years immediately following first returns of harvestable hatchery fish display pronounced
increases in angling effort and record high estimates of wild steelhead caught and
released (mandatory). Catches tend to have been sustained despite conclusive
evidence of declining abundance in index streams.”
Anglers can choose to protect wild steelhead
“The angling community may wish to contemplate leaving a smaller and softer
footprint on all wild fish or risk the steady erosion of longer term opportunity. A sobering
reality is that the trends in stream fishing opportunity throughout virtually all of
southwestern British Columbia have manifested themselves in a very few generations of
steelhead. Ignoring history and assuming trends will be stabilized or reversed in the
absence of attention to fishing impacts is unlikely to produce a desirable outcome.”

2 comments

  1. Randall Says:
  2. interesting read...

    a couple of points, I'm glad they hit on exposure to air as this is something most folks don't think about a whole lot. I know that we all have done the grip and grin photos (myself included), but those results are striking for even having them out of the water for 30 and 60 seconds. Besides, IMO, I prefer pictures of fish in water anyways, or close-ups...they're just more artistic if you ask me.

    second, with regard to fishing methods, I think it is a stretch to lump glo bugs and other egg imitations with the use of shrimp tails and other baits that emit scent. I personally rarely fish glo bugs, not really sure why because I nymph a fair amount.

    I actually enjoy nymphing nearly as much as much as swinging through a nice run. But for me, I always have a tendency to work my way pretty fast through a run or stretch of pocket water regardless of the method I choose to use for that particular piece of water...if I don't get a take on the first or second drift, I'll move on. Do I show my fly to every fish in a particular stretch? probably not, but who cares? not me...sorry for getting side-tracked there...

    one other thing that you mentioned was that you tend to get fish in as quickly as possible. I think that this is another area where anglers could stand to improve on. I think folks just love to see fish run, and run far...IMO the best thing you can do is get them in as quickly as possible, unhook them in the water and let them be on their way. I'm always guilty of muscling my fish in and have lost a few this way, but I've never felt like I was missing out on something. When I land a fish and the instant I get it unhooked, it's shooting out of my hands, I know that I did everything short of not fishing to ensure of the survival of that fish.

    cheers,
    Randy

     
  3. Mark Says:
  4. Thanks Randy,

    Though not technically bait,I put glow bugs,corkies and artificial eggs,yarn balls etc in that category because,fish respond to and are hooked by those methods as if they were real bait. Just my opinion on that.

     

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