While they can be very popular sportfish in some parts of the world, and have a small following here in the U.S., carp are generally considered a serious nuisance to most anglers and water users in America.  This is particularly true in the Midwest, where carp have taken over a large percentage of lakes and ponds, mucking up the bottom and destroying plant life, making it hard for other fish to survive.  You can read more about carp in one of my previous blog posts, entitled Carp…Those Pesky Critters!

Although carp have destroyed many midwestern lake ecosystems, University of Minnesota researcher Peter Sorensen believes that it doesn’t have to be that way.  With support from a number of different user groups and agencies, Sorensen has begun research on potential methods to eliminate carp in lakes. 

Efforts to remove carp from lakes can be successful, but require huge amounts of time and labor, and sometimes aren’t cost effective.  Sorensen is working on ways to change this, like developing pheromones to lure carp to a central capture location, or create scenarios where other fish eat juvenile carp.  Time will tell whether or not such methods can prove to be effective, but if they are, they will benefit people with carp problems all around the world.

Read more about the potentially groundbreaking research here 

If you’ve been following the Fish Geek blog regularly, you might remember a post I put together about proposed regulation changes in Idaho’s Silver Creek.  I interviewed Magic Valley fishery manager Doug Megargle about the proposed changes.The controversial regulations would have allowed anglers to keep brown trout in this popular fly fishing destination and change the way fishermen could access the river.  Below is an email I received regarding the update on the public process and the decisions recommended by the Idaho Department of Fish and Game.  The region has recommended that the changes in Silver Creek not go forward, mainly because of the division in public opinion and the lack of strong public support for the changes.

While fishing off the south coast of Grand Cayman, an angler noticed something peculiar floating at the water’s surface.  What he found turned out to be an incredible scientific discovery. 

McPherson ‘Dorson’ Wright found a 7.5″ Great Swallower that had swallowed a 34″ snake mackerel!

Without the picture, I wouldn’t have believed it myself. 

Find more info here

This just in.  A lawsuit from special interest groups has caused the U.S. Fish and Wildlife Service to reconsider the listing of Bonneville cutthroat trout under the Federal Endangered Species Act.  The Center for Biological Diversity, Biodiversity Conservation Alliance, and Pacific Rivers Council introduced the suit, citing that the trout are headed for extinction.  This comes after a 2001 decision by the USFWS that the status of the subspecies did not warrant listing.

Bonneville cutthroat trout are native to the Bonneville Basin, which encompasses most of the state of Utah, and parts of Wyoming, Idaho and Nevada.  The Utah Division of Wildlife Resources estimates that the species has been reduced to about a third of their historic range.

State agencies have been working hard to preserve and restore cutthroats and their habitat to avoid federal listing, which would bring in added restrictions that would potentially hinder many activities in the state.

I work in the Logan River in northern Utah, which supports one of the few remaining healthy meta-populations of native Bonneville cutthroat trout.  My research is focused on brown trout, which compete with Bonneville cutthroats in parts of the Logan, and I’m interested in understanding the environmental factors that give cutthroat trout an edge over the brown trout in the river, and allow cutthroats to persist in the higer elevation areas of the Logan.  This research is funded primarily by the Utah Division of Wildlife Resources, which is certainly motivated to protect cutthroat trout to prevent ESA listing.  

I’m not sure exactly what the specifics of the potential listing would entail.  The real question to ask, in my opinion, is how the subspecies would benefit from federal listing.  Additional federal funds would certainly be helpful, but would the benefits of additional money be offset by the potential hindrances caused by further federal control over private property? 

Tom Remington consistently addresses such issues related to the Endangered Species Act at his Black Bear Blog. 

Whether or not listing is deemed necessary, hopefully we can continue to find solutions that benefit both trout and people in the long run, and restore the Bonneville cutthroat trout in an acceptable manner. 

The Wisconsin Department of Natural Resources is considering killing about 6,000 double crested cormorants  in Lake Michigan and on the shorelines of Green Bay, in order to reduce their predatory effect on sport fish. 

The DNR hasn’t officially announced the plan just yet, but it’s sure to receive tons of criticism from bird enthusiasts and animal rights folks, while garnering support from many anglers.  The plan would intend to cut the numbers of the once endangered birds to about half of their current level. 

Cormorants have recovered from low population levels all around the country, and are beginning to present a challenge to fishery managers in many areas.  For instance, cormorants are believed to be a significant cause of predation on Atlantic salmon in rivers in the northeastern U.S.

The issue of predator control has been a touchy one, however, which has made it difficult for fisheries managers to ‘get things done’ when they need to.  One could argue about the effectiveness about cormorant control, and I am personally unaware of the research behind this topic, but I certainly believe that experimental evaluation of these control projects is important in determining their effectiveness. 

The Wisconsin DNR cormorant program is sure to be controversial, but I certainly hope it goes through, and can be used as an additional learning tool to allow us to evaluate how effective these control efforts truly are, and if these efforts should be practiced in other situations.

Read the news story here 

Scientists have discovered a fish that can live for months at a time out of the water!  Recent observations have identified that the mangrove killifish, which lives in swamps in areas like Florida and Belize, spends a good portion of its life living inside trees at the water’s edge.  When pools of water dry up, the fish apparently slithers into cracks and spaces in the logs of mangrove trees.  What a cool way to combat dry climate!

Read more about the mangrove killifish here 

Recent research from Stanford University has shown that some genetic mutations in fish can actually be linked to sleeping disorders!  The research used zebrafish, and showed that the fish did in fact sleep.  The scientists say that their findings highlight the potential of using these fish to discover why humans suffer sleeping disorders.

Read more below:

Fish enjoy a good night’s sleep

Study finds fish suffer insomnia

Man, it’s been quite a week!  In fact, the past couple of weeks have been sort of a blur.  In between finishing up a mule deer hunt and trying to find time to hunt for elk, I spent a week at a conference in West Yellowstone, MT with trout biologists from around the world.  I had the chance to fish the Henry’s Fork of the Snake as well.  Lots and lots to do now that I’m back from that mini-vacation.  My advisor and I are working on submitting a couple of papers for submission to a peer reviewed fisheries journal, and I’m trying to keep up with classes and gear up for the coming field season (I start brown trout redd counts in just over a week).  Plus, trapping season will be in full swing in a couple of weeks too! 

I have tons I’d love to write about here on the blog, but I’ll just have to see how things play out.  The conference I attended sparked lots of ideas and thoughts about certain aspects of the fisheries field.  When time allows, I’d like to put together a little “Wild Trout Series”, a series of blog posts about wild trout conservation and management.  I also have a little something to put together on Atlantic Salmon restoration (spurned by recent discussion), something about Tiger Trout (earlier committment), and a review of Forrest Bonney’s new book about maine brook trout, Squaretails.   But until then, I’ll try to get blog readers caught up on recent news and events in the freshwater fisheries arena.  Thanks for reading, and stay tuned!

For a few years now, I’ve been skeptical of the fish consumption advisories showing up in almost every state in the U.S., as a result of concerns over the effects of mercury.  We tend to take most things that government tells us as fact without much questioning.  I mean it’s written down on paper, in publications….”Don’t eat too much fish….mercury poisoning…” and so on.  But what data are these advisories based on?  I mean, it’s usually better to take a precautionary approach to things, but how much do we really know about the effects of mercury levels on human health?  Or……has it even been proven that such effects exist?

The fish consumption issue, which has pertained especially to pregnant women, has been called to question by recent work contradicting government warnings about mercury.  Last week, a group of U.S. experts stated that pregnant women should eat more fish because the benefits to infant brain development outweigh the risks that trace amounts of mercury could negatively affect infants. 

the group of 14 obstetricians and nutritionists said the threat of mercury poisoning remains only theoretical, while the warnings have scared many pregnant women into not eating fish at all, robbing them and their babies of vital nutrients like omega-3 fatty acids, known to help brain development

“There has been no case of fetal mercury toxicity due to fish consumption reported in the United States,” said one of the experts

Estimates on the dangers posed by mercury come from people exposed in chemical spills. No major studies have shown that mercury from food or vaccines has caused brain damage to mothers or children.

Interesting stuff, to say the least.  Read the full story here

I remember coming across a 20 year study from a coastal area where people consume much, much more fish that we do in the U.S., and had mercury concentrations in their bodies at about 10 times higher than Americans.  As far as I can remember, a huge sample size over a long time period showed no noticable affects of mercury levels on human health.  I can’t currently find the study, I’ll post it if I find it.  Something to ponder.  We’re doing tons of research on the transport and levels of mercury and passing laws and restrictions, and we’re not even sure how it affects humans. 

The state of Colorado will soon add water temperature standards to pre-existing standards of toxic pollutants.  Water temperature is very important for fish survival, and triggers the timing of fish spawning and other activities.  The state hopes that restrictions to activities that affect water temperature, including diverting water and reducing stream shading, will ultimately protect native trout species.

See the story here