Thursday, April 19, 2012

Black Marks, Blotches or Spots on Bass...OH MY!

I, like many anglers in my region, have been catching both largemouth smallmouth bass that exhibit large irregular black blotches or spots for many years now.  When I first started noticing fish with these weird markings, they occurred mostly with largemouth.  In recent years, I've been seeing them in smallies too.  The bass that I've caught with the spots were large adults and appeared to be really fat and healthy.
Black blotches or spots, like the ones shown here on a fat healthy largemouth bass from the Upper Tidal Potomac River caught by my buddy Bob Barber, are nothing to worry about.
In addition to the local waters that I fish, anglers in other states and, from what I've read, in Canada, have been seeing this phenomenon as well.  Naturally, when weird stuff happens to fish, anglers and biologists alike tend to think that the causes surround parasitic activity, water quality issues, or mishandling of catch and release fish.  These concerns turn to complaints and assumptions, and eventually research into the potential problem, and rightly so.  That's how the process usually works.

So, what are the spots and are they anything to worry about?  The condition is termed hyperpigmented melanosis, which is a fancy term for pigment discoloration.  The condition seems to occur in larger adult fish more often than juveniles.  The spots don't appear to be permanent.  Often, the coloration often returns to normal after a period of time.  And, researchers have found the fish exhibiting the spots seem to be otherwise very healthy.  Of the ones that I've caught over the years, I tend to agree, they seem very healthy.
The black blotches occur just about anywhere on bass, even the lips as shown here from a largemouth caught in a small Maryland lake.  The patterns can be simple spots, or large irregular blotches.  I think that they give the bass character!
Anglers are increasingly reporting occurrences all over the country that, in some cases, are on waters that are already troubled by poor water quality or pollution.  The fears about their home waters may be well founded, but perhaps the link to the spots may not be.  Reports of people catching fish with the spots seem to be increasing, but it doesn't necessarily mean that the number of affected fish is increasing.  People are noticing, and with the amount of free exchange of info over the net, are simply talking more about it.
Here's the same bass shown in the previous picture, displaying several spots and blotches on the lips, body, gill and fins.
Researchers speculated for some time that stress of some form may be the cause.  Stress resulting from fish handling (perhaps catch and release), parasitic activity, disease, natural injuries to the skin, bacterial or viral infections, pollution or poor water quality have been suspected causes.  Even though all of those could possibly result in the condition, there's no evidence to directly support that this type of melanosis is caused by those factors, and researchers have stated that the symptoms could very well be genetic or hormonal.

In many fishing forums, more and more people are posting fishing reports with pictures of affected fish along with voicing their concerns.  With all of the buzz about blotchy bass, and after catching a few myself, I decided to do my own research.  I really couldn't find much on the web except that nobody really knows that causes the spots, that the fish appear healthy, and that researchers at Auburn University are studying the phenomenon.  I was not able to find anything about the results of the Auburn study.

Gene Mueller, who writes and awesome blog that I urge you all to visit, Gene Mueller's World of Fishing & Hunting, mentioned to me that these spots aren't anything to worry about as he had spoken to Maryland DNR officials, and they assured him that the spots were nothing to worry about.  In addition, the Maryland Fisheries website mentioned in their fishing report in reply to a post something to that effect.

I wholeheartedly agree with Gene and am not worried about the spots.  But I'm not sure that the rest of the angling community feels the same way.  So, I wondered that, with all the increased concern about blotches on bass, maybe I'd address the topic here to put forth some of the latest info.

Wil Wegman recently wrote a detailed piece in the April issue of B.A.S.S. Times on the topic.  He interviewed various people researching the spots, and shared what he learned with the B.A.S.S. Times followers.  he relates that former Professor John Grizzle of the Southeastern Cooperative Fish Disease Laboratory at Auburn University and Associate Professor Jeff Terhune, who currently runs the lab, concur on their take on the spots. 

Dr. Terhune states that "...there could be lot's of causes, some anecdotal and some potentially real.  Even spawning may create lesions or sores that heal in this manner.  Genetics can also play a big part.  Overall, most of the hyperpigmentation that I am aware of causes no harm to the fish, otherwise you would see fish in poor condition (i.e. thin) or with some other diseased condition."

Mr. Wegman also reported that Dr. Terhune believes that "though anglers are targeted as causing the strange bass coloration, it's far more likely to be a natural occurrence that has little to do with how much a bass has been handled."  That doesn't let anglers off the hook though, as it's our responsibility to carefully release our catch (if that's our intent) and handle the fish with the utmost care as much as possible. 

Then again, many people are questioning what, in some bodies of water, seems to be a more recent phenomenon.  The Susquehanna River in particular where more and more smallmouth bass seem to be exhibiting the spots than many Susky veterans can ever remember.  Recent water quality issues that are known to cause other problems with the health of the bass populations there, along with dramatic decreased young of the year counts, have resulted in recent regulations closing all bass fishing in large stretches of the popular river during the spawn, including catch and release fishing (beginning May 2012).  Perhaps there is something to this. 

Some veteran anglers are asking for more detailed studies by Pennsylvania officials to see if the spots are indeed linked in some way to the troubles of that river.  Perhaps they'll find out one way or another.  If they're related, they could be an indicator of bigger problems.  At the very least, even if the spots prove harmless, more attention would be given to address the real causes of the decline in bass numbers there.  More to come I'm sure.
This Susquehanna River smallmouth bass shows multiple black spots.  Anglers that frequent this popular river are extremely concerned about increased occurrences of the spots in their river, especially in light of other problems related to pollution there.  Photo Courtesy of Bill Yingling, M.D.
So, in summary, as Gene pointed out to me months ago, the black blotches appear to be nothing to worry about, at least on the individual bass studied.  But, could they be an indicator of bigger problems on some bodies of water?  Our focus should be on improving the water quality as much as possible, especially if the spots really are an indicator that is tied to water quality.  The bigger problems that have already identified are decreased young of the year smallies in our upper rivers along with discoveries of intersexed bass, and bacterial lesions more than likely due to poor water quality and various forms of pollutants.  But that's a blog topic for another day.

By the way, I've been a lifetime member of B.A.S.S. for many years.  Their publications, Bassmaster Magazine and B.A.S.S. Times are highly informative.  They are a must for the serious bass angler.  I've saved every copy since becoming a member many years ago.  Often, the information found in both publications is useful to other anglers as well, especially topics regarding fishing politics and conservation.  I highly recommend both publications.  I'd like to thank Bassmaster and B.A.S.S. Times for their contribution and permission to share their research, and Wil Wegman for writing such an informative article.


William L. Yingling M.D. said...

The increased frequency of these affected fish is not from better reporting. Never saw this in the upper mainstem where I fish until 2010 and I've fished the same water since 1976. It is a new occurrence in these waters and it comes right on the heels of intersexing and bacterial infections that are killing the fish. And I might add that we do not see all the fish with ulcers and sores die either and we do not know if the fish with black spots are dying. I've seen many human beings with cancer who looked quite healthy until late in the disease.
Accepting it as not being harmful to the fish or not being an indicator of water quality is a dangerous assumption to make because of possible public health ramifications.
We need science not suggestions to find out the cause.

William L. Yingling M.D.

Fat Boy said...

Thanks for your input Bill, much appreciated. I think that in many cases nation wide, like the Lower Potomac River, the spots are not a new phenomenon and may not be an issue. However, in the case of the Susquehanna, I think that you are on to something. I'm not ending the story with this latest post.

I think that the next post will be about the case of the Susquehanna, not just about the recent occurrences of blotches being reported, but an all of the above approach detailing the troubles of the river. I look forward to working with you to bring these issues to the forefront on FBO and other fishing forums.

Fat Boy said...

I'd like to add that if science confirms your hypothesis, other bodies of water could benefit from improvements in management and water quality efforts. Let's hope it's not too late.

Anonymous said...

I havent seen any bass with those blotches around central Maine as of yet FB.

I plan on snagging quite a few more this summer and I'll be keeping an eye out for anything odd. I'll post any findings here and MFF though.

Cheers buddy,

Kirk Mantay said...

Great post - hadn't heard of or noticed this problem yet - almost all of my largemouth are out of ponds and lakes.

And yes, the spectre of endocrin disrupters is hanging heavily over the fishing community right now. Looks like we are the canaries in the next coal mine...

Fat Boy said...

Thanks BT, I'll be following your posts on MFF.

Thanks for the feedback RM, much appreciated. I was out the other day on Triadelphia and caught some decent largemouth and a few nice smallies too. Some of the bass had the black spots, and one had them on both lips. I have pics, and will post them on the follow up once I get some info from the folks that I've emailed. I'd be suprised if there's a water quality problem in that watershed, at least that far up. But hey, maybe so.

Unknown said...

Our PFBC has sent samples to the USGS (most likely Dr. Blazer) for testing. She indicated some time ago via the Lower Susquehanna Riverkeeper that an accurate microscopic examination would be required to determine *exactly* what these spots are. However..she also stated that mwlanin production is a function of the endocrine system; and we already know the Lower Susquehanna is impaired by chemicals that disrupt the endocrine system. It's not a difficult leap to see that there *could* be a connection.

I fish below Harrisburg mostly, and I've seen some fish with these and with the open 'sores' as well. I know this river is sick.. but then of course our own PADEP chief begs to differ---even when requested to declare the river impaired by our own PFBC head, John Arway. Of course, that means TMDL limits and monitoring, etc..etc.. all bad for business; and we know our Governor here wants the state WIDE open for that.. To the devil with the ecosystem, and the health of people who drink the water, breathe the air..etc..etc..

John Potter said...

Wow, that really impressed me! I like your ideas. And the cartoon made it even better! Thanks for sharing your concept! Cheers.
Fatboy Bean Bag Chairs

Fat Boy said...

Thank you John! I like the name of your chairs :)

Anonymous said...

I have been catching more of these fish lately and to me it seems as though I only catch them in waters that are known to be polluted. I think there is a connection, probably not a dangerous one but I connection, I have yet to catch a bass with these spots in an area that I am not positive is polluted

Fat Boy said...

That's good to know. It's hard for me to say in my area, but I'd bet that it's just about the same here too. I would say it's very likely in Maryland that there is some form of pollution in every body of water that holds bass.

Sorry Dwayne for not responding sooner, but I hear you loud and clear. Hopefully people put people in power some day that will make a positive difference on the Susky. Voters can make a difference. Maybe reading your's and Bill's comments will reach the right people some day.

Unknown said...

I just caught a Largemouth Bass about 30 mins ago that had these black blotches all over it... Almost covered the entire top of the fish and the whole tail.... kind of freaked me out some since I have never seen anything like this in over 20 years of fishing large mouth bass. I took video of it and came back to look up what these blotches were.. This I can tell you about the pond it was caught in.. Extremely pollution free and unavailable to anglers, military protected water way by the air force so you can not stop and fish... I caught the Bass in Dover, Delaware and from everyone I have asked so far they have not seen this before... Has there been any head way on research done to figure out what the blotches are? Like I said I have video and the blotches almost covered the entire Bass..

Fat Boy said...

Thanks for the comment and question R.J.! I need to do some research on this. I haven't heard much new other than from some discussions about the Susquehanna and it's problems. My opinion is that these spots are stress related somehow and are harmless as such. But, they could be indicators of a greater problem, such as pollution, but not necessarily in every case. I will see what I can find out and try and post on the topic again.

Anonymous said...

Hi all I have seen fish in the St.lawrence river with this condition. I am wondering if the cause is road salt. It is only been the past 10 years or so they have been using liquid salt on the roads
We have ships bringing it in every day millions of tons sit along the shore line waiting to be trucked out. just a thought.

Fat Boy said...

That is an interesting point about the salt. Since PA gets some pretty harsh winters, that might be something to look at.

The more that I hear about the condition of the fishery, the more that I'm inclined to agree with Bill. These spots may be harmless in some cases, but when they appear so often in places like the Susquehanna, it tells you those fish are stressed often. Pollution would be a likely suspect and these spots may indicate that problem. There are fish that have lesions and sores being caught more and more. Hopefully, more studies will lead to some potential solutions to this likely problem.

William Yingling said...

Update for those interested. A British researcher found similar black spots in coral trout and found that it represents melanoma, a skin cancer also seen in humans. Here is a link.
He was sent some specimens from Susquehanna smallmouth and I am currently awaiting his results.
Smallmouth in the Susquehanna contain more than 30 organic chemicals harmful to humans and millions of people drink this water. Think about it!! Don't let any agency tell you it is harmless or irrelevant.
William L. Yingling M.D.

Fat Boy said...

Thank you Bill! I look forward to his response to you and his findings. If you don't mind, could you please post the info again here? This topic has turned into a very popular one and many would like to learn more about it, including me. Thanks again to contributing!

William Yingling said...

Government, industry and yes even many environmental groups are ignoring the growing problem of chemical endocrine disruptor contamination of our water supply. The problem is not new and if any are interested in seeing how and when this problem began and how it is affecting humans... they need to read Rachael Carson's book entitled "The Silent Spring." Carson was a marine biologist from Pennsylvania.
The elevated frequency of the occurrence of the black spots (a likely form of skin cancer)along with intersexing and increased death rates from infection among smallmouth bass in the Susquehanna River is truly the "canary in the coal mine." Pennsylvanians who eat the fish, recreate in the water and millions who drink the water are guinea pigs for one of the largest uncontrolled experiments on the effect of low dose pollutants on humans. I do not think it will turn out well.
William L. Yingling M.D.

Anonymous said...

Nothing to worry about have seen fish with these for 40 years and i fish a lot.

William Yingling said...

Good idea!!
Don't worry!! Be Happy!! Just bury your head in the sand and ignore it.

Unknown said...
This comment has been removed by the author.
Anonymous said...

In March 2015 the PFBC did an electroshocking survey in the Susquehanna River near Selinsgrove, PA. 26% of the smallmouth checked had black spots. One in four is quite alarming.
Chemical pollution knows no physical boundaries whether it is the pristine lakes of Maine or the Great Barrier Reef in Australia.
Just because it happens in numerous places around the world we cannot accept it as normal or speculate about what it is. Cancer in children was virtually non-existent in it is the #1 or #2 killer of children depending on age group.
We need scientific investigation to explain what the black spots are and what is causing them...not speculation.
William L. Yingling M.D.

Fat Boy said...

Thanks Bill. Have you heard anything more on this topic?

William Yingling said...
This comment has been removed by the author.
William Yingling said...

At this point I know of no new scientific research on the problem. I continue to catch smallmouth in the Selinsgrove area with 1 in 4 (25%)involvement with black spots.

The British researcher that diagnosed this problem as cancer in other species of fish has done no further research.
The Pennsylvania Fish and Boat Commission has refused repeated requests to do more sampling of these fish using the sophisticated techniques needed to diagnose cancer (melanoma).
Meanwhile 6.5 million people along the Susquehanna drink the water that has caused the various diseases that these fish swim in.

William L. Yingling M.D.

Anonymous said...

I like the information on the spots but in one small pond i fish only small ones have these spots all over them but not on the belly so they are largemouth.