Reviving Fish?

[Rockport24]

Hey guys, I was watching some fishing show on Versus last night and it had a segment with a marine biologist and he said that the way a lot of anglers revive fish by pushing them back and forth in the water to get water over their gills can be harmful to the fish. He noted that fish gills are meant to take in water from the front, and that water entering from the back can be harmful.
What do you guys think?

[fishsmith]

I just try to get the fish back in the water asap, the main reason is I want my line back in the water asap.

[daceman63]

if it's a keeper the fish has a much larger concern than me washing water over it's gills in the wrong direction.

[The Dad Fisherman]

I saw that same show last night.....they were catching some Monster Pike in canada.

I remember he also said that you never let the fish touch the deck of the boat when you bring them in as they might get "Rug-Burn"

[Rockport24]

yeah, he did say that! I guess dragging them along the rocks is also bad???

[Young Salt]

when i revive a spent fish, i force it forward and gently pull it back toward me.

just holding it in current is ideal.

[baldwin]

What matters is that water is circulating over the thin membranes of the gill filaments, so the CO2, which has a higher concentration than the surrounding water, can diffuse out. The oxygen, which has a higher concentration in the water than in the fish, diffuses in. Shouldn't really matter much which direction the fish is getting pulled in. I'll get back when I check my notes, I vaguely remember something about the way the blood vessels are arranged for maximum oxygen absorption.

[baldwin]

I didn't actually find my notes yet, but do remember something about cross-current ventilation. I don't remember if it's in all fish, or just the scombrids (tuna, mackerel). The blood vessels go in the opposite direction of the water flow through the gills. This is so that the oxygen-poor blood is first exposed to the gill filaments farther back from the mouth, so it contacts the water with the most oxygen removed (though still more oxygen than the blood). As the blood moves forward and extracts more oxygen, it keeps contacting water with a higher and higher oxygen content. This is so that even as the blood absorbs oxygen, it is continuously exposed to water with a higher concentration than in the blood. Thus, it maximizes oxygen diffusion into the bloodstream. I don't see, though, where it might harm the fish by moving it back and forth through the water. It would still facilitate oxygen absorption, just not as efficiently as continuously towing it head-first, as in throwing an albie hard into the water.

[FishermanTim]

It might also have something to do with debri getting forced into the gills on the pull back.
I prefer (when possible) to pull the fish forward and drag it in a figure 8.
I also look at the dorsal fin to see when it stands up. To me, that's a sign that the fish is building strength for a burst of energy (to escape).

[baldwin]

You may be right. Gill rakers are bony projections that are on the forward edge of the gill structures, keep stuff from contacting the fragile filaments that do the gas diffusion.

[patpatriot]

"I remember he also said that you never let the fish touch the deck of the boat when you bring them in as they might get "Rug-Burn""
__________________

when a bass may slide on the side of a boat deck, especially the rough footing areas, it removes the slime which protects the fish from infection or desiese, overhandling does this too.

Fish that overwinter in the chesapeake caught striped bass skin infection easier when they had no protection. Also, does anyone know if the disiese is still a problem or not?

[Rockport24]

wow, good info guys. and good research Baldwin!

[OSSCA]

Originally Posted by patpatriot

"I remember he also said that you never let the fish touch the deck of the boat when you bring them in as they might get "Rug-Burn""
__________________

when a bass may slide on the side of a boat deck, especially the rough footing areas, it removes the slime which protects the fish from infection or desiese, overhandling does this too.

Fish that overwinter in the chesapeake caught striped bass skin infection easier when they had no protection. Also, does anyone know if the disiese is still a problem or not?

Here's some info on the disease you speak of David A. Ross Ph.D. Scientist Emeritus
Woods Hole Oceanographic Institution
Woods Hole, MA

Stripers, for some unknown reason have a high susceptibility for mycobacteriosis, which has infected resident fish in Chesapeake Bay beginning in the 1980s. Recent studies, including the recent USGS/NOAA workshop on mycobacteriosis have shown a broad and increasing rate of infection.
Fish with mycobacteriosis develop a bacterial infection that causes inflammation and ugly lesions or sores on their skin; it also causes tissue destruction and formation of scar tissue in one or more organs, especially the kidneys and spleen. The disease has been characterized as a “wasting disease” because it results in a loss of body mass and causes fish to look emaciated.
It is not known how fish actually become infected. Do they get it from their food, from stress, or from the water? And can they pass it on to others that swim nearby or when in a crowd? Among the possible reasons for the increase in mycobacteriosis (up about 62% from 1998 to 2005) are overpopulation and/or poor water quality combined with insufficient food sources.
The relationship between the occurrence of the disease and mortality of striped bass has not been definitely determined but there is evidence that mycobacteriosis may be having an impact on the bass population - more study on this question is needed. Some fishery biologists show that because of mycobacteriosis, natural mortality estimates – number of fish that die from natural causes – have increased dramatically for small bass in recent years, to perhaps as much as triple previous estimates. This could mean that assumptions surrounding current striped bass population levels are flawed.
Most of the fish with the disease are year-round residents of Chesapeake Bay although there have been reports that some infected fish are showing up as far north as New England waters. Other species in the bay, particularly Atlantic menhaden, a prey species of stripers and bluefish, also show increasing evidence of mycobacteriosis infection. One study showed much smaller numbers of infected fish in Delaware Bay to the north. Stripers further from the Bay display signs of the infection less often, perhaps because the migrating fish spend only a few months in the Bay while spawning, or perhaps because the symptoms lessen or are eliminated as fish find better sources of food and cleaner and cooler open water.
The infection is age-dependent and is even found in young-of-the-year fish. Infection rates can be as high as 50% for 3 to 4 year old males and up to 80% for age 6-year fish. Skin lesions are observed more in the fall than in other seasons.
People handling infected fish may develop skin lesions that can be difficult to treat. These fish should not be handled by individuals with cuts or sores on their hands. The workshop participants did not concern themselves with the health implications of handling or eating infected fish. Perhaps this issue is perceived to be too politically charged, but more understanding of the possible health ramifications of delivering infected fish to the seafood consuming public would seem to be of critical importance.
What happens to the sick stripers swimming in Chesapeake Bay? This is an important question since estimates are that Chesapeake Bay and its tributaries, during breeding times, hold about 70 percent of the Atlantic coast breeding stock. Mycobacteriosis usually causes death in an aquaculture environment but the effect on mortality in the wild is not yet certain. While the current mycobacteriosis outbreak may not as bad as it sounds, it certainly is not good. The mycobacteriosis problem combined with the smaller reproduction numbers from recent years, the continuing environmental decline in spawning areas, and the over fishing of breeding age fish doesn’t make the future look very bright.

[baldwin]

I've heard that an extremely high percentage of young Chesapeake bass have mycobacteriosis, with little chance of survival. That and the state of Chessy waters (nitrogen loading, toxic metals, etc) makes me worry about those bass. Hudson bass may play a larger role in our fishing in the future. Delaware Bay is also becomming a major player.

[Water Treater]

You will drown a fish if you pull it backwards in the water. When releasing a fish don't "walk it" backwards. Every body knows that.

[OSSCA]

Originally Posted by Water Treater

You will drown a fish if you pull it backwards in the water. When releasing a fish don't "walk it" backwards. Every body knows that.

[justplugit]

Originally Posted by FishermanTim

I also look at the dorsal fin to see when it stands up. To me, that's a sign that the fish is building strength for a burst of energy (to escape).

Good point.

[Woofish]

For years I have been a strong advocate for "Catch and Release". I have even devoted a whole page on my website to the subject. I have never heard about the problem of pulling the fish backwards. It is certainly something to consider, and I would like to hear more biological experts opinions. I routinely surf the net looking for new information on Catch and Release and will see if I can locate any more info on this subject. I am encouraged to see the response to this subject. Many of us are indeed concerned we are doing the right thing when we release our fish. I attach the contents of my Catch and Release page in hopes that it will help get some of the ideas to others looking for information.


Woo's CATCH-AND-RELEASE

Catch-and-release can play an important part in the maintenance program for any fishery. The striped bass has become one of the favorite quarry of the recreational fisherman and most striper fishermen are releasing fish because they are true sportsmen or are following laws that restrict both size and bag limits. Unfortunately, catch-and-release on the east coast from Maine to North Carolina has taken a hefty toll on the striper population. In 1999 recreational fishermen caught an estimated 14.2 million stripers, and they released about 90% of their catch. Sadly, of the 12.8 million stripers released, 1.02 million died from hooking or handling injuries. What can you do to improve the odds that the next striper you release will survive to be caught again or to continue its life cycle as a breeder? Below are some tips to help you answer this question. Please review these from time to time so they are fresh in your mind.



CRUSH BARBS ON ALL HOOKS. This applies to both lures and bait rigs. Hooks without barbs are much quicker to remove and cause less damage to the fishes flesh and a quicker release means less stress to the fish. Fishermen benefit as well as the fish. A quick release gets you back in the water quicker to get the next fish. Also, if you hook yourself by mistake the hook is easily removed. As far as losing fish because there is no barb, I have found by personal experience barbless hooks present very little risk. In fact I believe sometimes a barbless hook will penetrate better and the hook holds better because the fish is pulling against the bend in the hook. Try it you will like it.



MAKE A SPEEDY RELEASE. Don't waste time getting the fish back in the water. Have all tools required for the release handy. This would include such things as a net, pliers, measuring tape, tagging materials, and camera. Make sure cameras are loaded and ready to snap that picture. Time required to put film in the camera could result in a dead fish. Have a buddy help if it is a difficult release. Only tag fish in situations where it can be done very quickly, and only use tags that cause little trauma to the fish.



DEEPLY HOOKED FISH. Even with barbless hooks sometimes a fish gets deeply hooked. If the hook cannot be quickly and easily backed out, cut the leader as close to the hook as possible and get the fish back in the water immediately. The corrosive action of the fish's digestive juices and the salt water should get rid of the hook in a short time. Using bronze hooks is the best bet since they will deteriorate quickly. Stainless steel hooks should not be used.



USE CIRCLE HOOKS. Recently the Maryland Department of Natural Resources made a study, which suggested that using non-offset circle hooks could sharply reduce mortality of released stripers. Stripers caught on conventional hooks were deep-hooked about 5 times as often as fish caught on non-offset circle hooks. Since deep-hooked fish are much more likely to die than lip-hooked fish, using circle hooks is highly recommended. The study indicated that 53% of fish deep-hooked on conventional hooks died, while the mortality rate of fish taken on circle hooks was 23.5%. Overall, 9.1% of stripers caught on conventional hooks died, as opposed to only .8% for fish taken on non-offset circle hooks. It is obvious that a wider use of circle hooks will benefit the striper population. 6/29/01 Update. This month I tried circle hooks bait fishing with sand eels and clams at Cape Cod. I prefer plugging for my fish but on occasion I will bait fish if the conditions so dictate. I caught about 30 bass on bait with small circle hooks with crushed barbs, and every one was hooked in the corner of the mouth making removal very simple. I missed only one fish that picked up a bait. You do not jerk the line to set a circle hook just start reeling when the fish take the bait. Sizing of circle hooks I have found to be confusing. A 10/0 hook is about the size of a regular 5/0 or 6/0 hook. Make sure you know what you are getting if you buy them mail order. The only drawback of the circle hooks I experienced was that putting on the sandeels or clams was more difficult. However the baits stayed on very well.



THE BEST RELEASE. Fishing in waders or from a small boat offers the best conditions for a safe release. Using single barbless hooked lures are preferred. Slide your hand down the leader to the lure and twist the hook out of the fish. If it is necessary to handle the fish, do so with the fish still in the water.



RELEASING IN THE SURF. If conditions permit, release fish without bringing them on the beach. If this is not possible because of rough surf or you are fishing without waders, bring the fish gently up on the beach avoiding the dry sand. Only bring up the fish far enough to unhook it quickly. Gently pick up the fish and return it to the area beyond the wash where the water is free of much suspended sand. If the fish is not in good shape swim it a little to help it gain oxygen by forcing some water through its gills.

Make sure the fish is swimming up right and has some strength before letting it go. Sometimes it takes a few minutes of swimming the fish before it is ready to swim away.

A little TLC can do the fish a lot of good, and it should make you feel good that you did the best you could to do a good release.



AVOID USING NETS. Using nets is not recommended unless you are in a large boat where reaching the fish is not possible. When netting fish to be released, put them gently on the deck where they can be unhooked quickly and return carefully to the water.



HANDLE FISH PROPERLY. No matter where you are landing a fish if you must handle the fish do it as gently as possible and keep it to a minimum. Sometimes putting a damp towel over it before handling can calm a wild fish. When holding a striper, support under its head with your thumb in its mouth and your other hand under its mid-section. There are no teeth to worry about though the inside of the mouth can be quit abrasive especially with the big fish. Try to avoid removing the slime from any fish since this can result in the fish becoming diseased.



AVOID FISHING IN HOT WEATHER. The Maryland Department of Natural Resources 1999 study verified that the mortality of fish released in very hot weather was very high. They found that when air temperatures were below 95 degrees, the death rate of hooked fish was just .8%, but when the temperature got over 95 degrees the death rate jumped to 17.2%. If you do a lot of catch-and-release fishing try to schedule your trip when the air temperatures are more favorable to the fish being released. Fishing the cooler weather is also more enjoyable for the fisherman. If it is hot when you are fishing, take extra precautions to make your releases as quickly as possible.

[OSSCA]

Originally Posted by Woofish

For years I have been a strong advocate for "Catch and Release". I have even devoted a whole page on my website to the subject. I have never heard about the problem of pulling the fish backwards. It is certainly something to consider, and I would like to hear more biological experts opinions. I routinely surf the net looking for new information on Catch and Release and will see if I can locate any more info on this subject. I am encouraged to see the response to this subject. Many of us are indeed concerned we are doing the right thing when we release our fish. I attach the contents of my Catch and Release page in hopes that it will help get some of the ideas to others looking for information.

Here ya go,straight from the pages of the "biological experts" at URI
http://nsgl.gso.uri.edu/flsgp/flsgpg00008a.pdf

[Swimmer]

Intubation...........

[Andy D]

I will hold a fish by the tail and hold it uprite and into the current if any
This way the fish can pump water over it's gills normally. And as someone else said look for the dorsal fin to stand up . I think you can better feel the fishes energy when he is trying to swim away.

[baldwin]

True, Andy. When it's ready to go, it'll let ya know.

[numbskull]

Originally Posted by Woofish

For years I have been a strong advocate for "Catch and Release".


DEEPLY HOOKED FISH. The corrosive action of the fish's digestive juices and the salt water should get rid of the hook in a short time. Using bronze hooks is the best bet since they will deteriorate quickly. Stainless steel hooks should not be used.

Woofish, although I applaude and support your effort to encourage and facilitate catch and release, I am disappointed to see this misinformation about "digestable hooks" propogated. The mortality rate for different hook types in Striped Bass has been studied (though I cannot locate the reference at the moment, I had the scientific reprint once about 15 years ago). It showed, as you would expect, that biologically inert metals had the lowest mortality rates when hooks are retained in fish. Stainless steel had the LOWEST mortality rate. Cadmium plated hooks had the highest (b/o heavy metal renal toxicity). Bronze was somewhere in between if I recall correctly. Hooks DO NOT corrode out of fish, nor are they digested. They wall off and are rejected by an inflammatory reaction just like a thorn, piece of shrapnel, or other foriegn body would be if impaled in you. While impaled in the fish, the hook leaches metal into the fish's blood, hence the problem with plated hooks. If I can find the reference I will PM it to you.

[Woofish]

Numbskull - Maybe your not a numbskull. You seem to know what you are talking about. I would like to read the report you referenced if you ever find it. I plan to alter the contents of my C&R page. Thanks.

[baldwin]

I've read the same stuff. Cadmium isn't exactly an essential mineral. If you read the CT Hunting laws publication, there's an advisory against eating venison liver because of the cadmium content. I'm sure that deer liver has a small cadmium content (measured in ppm), insignificant compared to that of those hooks. And yes, stainless is pretty inert. That's why it's used in surgical implants.