Maybe at one time, years ago, fish hooks rusted rather quickly. Anglers were advised to leave a hook in the fish, if could not be easily removed and the fish was to be returned to the water.
Leaving the hook in the fish my not have ever been good advice. There is some question. But certainly most of today’s hooks don’t rust or dissolve easily.
I recently wrote a column about the subject and just recently received additional information from Eric Johnson, Florida Fish & Wildlife biologist, after he returned from a well-deserved hunting trip.
Wrote Eric, “You can spend hours and hours researching this topic on the internet, trust me! I could not find any authoritative studies that looked at hook dissolving rates in freshwater fish stomachs but did see some studies in other countries that looked at hook oxidation/toxicity generally in fish.
“One study I saw stated that stainless steel hooks didn’t rust as quick as carbon steel hooks and metals such as cadmium/nickel in hooks can accumulate in fish organs and potentially be toxic to them.
“I did find some studies that looked at fish mortality based on where fish were hooked and/or if hooks were removed or not; however most studies only held fish for up to 10 days to look at effects. It’s my belief that these types of studies need to be conducted for a longer time period.
“Results of studies on hooking mortality were often contradictory (as one might expect). Authors of some studies said leaving a hook embedded deeply in a fish gives it the best chance of survival while other authors said it is best to remove the hook. I agree with the latter and recommend removing the hook if at all possible because you just can’t guarantee it will dissolve enough for the fish to get rid of it and some of the metals in hooks may accumulate in fish organs.
“Deeply embedded hooks can also affect the fish’s ability to eat or digest food, potentially leading to starvation too.
‘Since fish hook construction has come a long way in the past decade or two, with manufacturers using less corrosive materials and better coatings during their construction, it is my personal belief that most hooks do not ever completely rust away in freshwater fish stomachs.
‘I don’t believe that a fish hook will dissolve much after five days in a bass stomach. Some hooks may corrode enough that the barb or point dislodges from throat/stomach wall so fish are able to regurgitate them or pass them through the rest of the digestive track and out the anus but I wouldn’t expect this to always happen. It all depends on the size/species of fish, type/size of hook, hooking location, materials in hook, etc.
‘I don’t think anyone will ever be able to fully quantify this occurrence though. I saw a few publications and personal observations where fish hooks were observed in fish throats or stomachs for up to six months after being placed there.
“Bottom line is that some fish will die after being hooked regardless of whether the hook is removed or not. It’s tough to quantify the percentage exactly given variables such as hook size, hooking location, fish species, water quality/salinity, etc.
‘If the law allows it, I think it’s best to harvest a fish that you can’t remove the hook from and take it home to eat or give it away. Mother nature has a great strategy for replenishing fish in aquatic systems by allowing females to produce thousands of eggs each year.
“Largemouth bass are a prime example and given the ‘catch-and-release’ mentality of bass anglers nowadays. It sure wouldn’t hurt for bass anglers to keep a few fish here and there, especially here in Florida!”