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jhoekstra

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  • Gender
    Male
  • Location
    Tremont IL
  • Interests
    Hiking, fishing, listening to people tell stories, reading, scientific thinking that is not too excruciatingly precise.

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  1. Okay, I'll be the first to bite on this. "Damnably inconvenient" pretty much sums up fly fishing! Except I have found no easier way to catch spawning bluegills. As for fishing deeper water, I think most might change up the leader a bit (shorter and heavier) but would not insist on switching to a 7 wt before throwing streamers or other weighted flies. And wouldn't use a sinking line unless it was really deep water they were targeting. I'm no good at it, judging by the fish I've caught, but I use a 5 wt with floating line to hurl weighted streamers around. In most places they will get to the bottom if you cast and mend effectively. But really, Tom L is the one the explain all that!
  2. I did my MS in Arizona... the rivers and streams there have an amazing assortment of local and weird specialties, which is what happens in isolated habitats. They are the aquatic equivalent of the Hawaiian Islands. I saw stream communities that were totally devastated by green sunfish and crayfish, both of them introduced since the 1950s. Invasive bullfrogs are doing huge damage to wetlands, eating everything they can cram in their big mouths. Smallmouth bass are already notorious for their effects on California streams, as are rainbow trout for their effects on lakes. With time some of the natives will likely adapt or the exotics will be regulated by diseases that catch up with them in their new digs. But a lot of the native species are just terribly vulnerable to predators. I studied a desert damsefly that had a neat adaptation to dropping water levels in the early fall: the adults would crawl way down deep to lay their eggs, carrying a film of air on their bodies like SCUBA divers. Not compatible with fish. What do anglers care? Sometimes exotic species support an incredible fishery. Other times, they reach huge densities that are food-limited and you wind up with a habitat full of scrawny fish that nobody wants to catch anyway. In my book the species native to isolated habitats have an intrinsic right to exist, and I think most anglers would rather fish for native species interacting with others in a rich community... or if a stream is naturally fishless, just take a hike with the camera and see how it bursts with life.
  3. 1) Some dams keep some invasive species out of headwaters on some rivers... remove the dam and you open up the upstream reaches to whatever exotics are established downstream. Quoting myself. Why? QUESTION: Has anyone clearly seen this pattern with Asian Carp? Do you know a dam where the carp stop, and if so, can you see a huge difference in the fishery upstream versus downstream? I'm thinking probably not given how well those things jump, but maybe the right dam in the right place...?
  4. Broad brush: dams are not much good for smallmouth. Flow control is another problem: working together with levees, dams screw up the natural "flood pulse" that keeps rivers and wetlands connected and productive. Also add the terrible danger to canoeists and kayakers from low head dams, by far the most dangerous spots on most rivers around here. Except. Against all the negatives, maybe two ecological positives: 1) Some dams keep some invasive species out of headwaters on some rivers... remove the dam and you open up the upstream reaches to whatever exotics are established downstream. 2) Sediment stabilized behind a dam may indeed be very toxic, but it's buried. Destroy the dam and you either have to move the sediment or let floods redistribute it for you. This can mobilize a lot of legacy PCBs, mercury, etc. There is also the issue of the positive social and economic functions of dams, which do exist even if we don't all equally value them. Somebody else who uses the river for navigation, municipal water supply, power generation, or flat water recreation may value a dam. So might a downstream landowner whose property is protected from flooding. In rare cases taking a dam out might do more harm than good. It's usually a moot point because they deteriorate and fill up with muck over time, so there isn't much choice with an old dam: either take it out or let it fall apart on its own terms.
  5. jhoekstra

    UV Flies

    I think Rob G makes an important point. The only way you could detect UV light being reflected would be with a UV-sensitive camera. Your camera "sees" visible light, which fish no doubt see as well. When you flood a fluorescent material with UV light, a lot of energy is transferred to the pigments and then they fluoresce noticeably, especially in an otherwise dark environment. Some other things that fluoresce really strongly: highlighting markers and scorpions. It's really fun to look for scorpions with a blacklight. Cool images! Jon H
  6. To me, they look like aquatic insect emergence traps. Aquatic insects emerge and fly up toward the light. They are captured in a mesh bag at the top. I set these out for some of my studies on stoneflies. It's a very effective way to get freshly emerged specimens, and you can also estimate the rate at which bugs are coming off because you're sampling a defined area. Maybe AC has it right, but then I don't see why you'd have the tent-shaped structure up top. The exact trap design isn't familiar to me so I could very well be wrong. But the way they are laid out makes me suspect aquatic ecologists are at work. Somebody trapping minnows wouldn't be so fussy about the spacing.
  7. When I did fisheries stuff with electroshocked fish, it was always a wet wooden board with a vertical edge (stop) and a built-in ruler. They get very smooth with repeated use. But when I did insect work I took pictures of bugs with rulers or scale objects in the same frame and on the same plane. If the distance and angles are correct it is very easy to measure any point to point distance with free software, after calibrating to the scale object. Assuming: no measurement is error-free, and precision is not a huge deal, a picture of the fish with a scale object in the same plane should work. More trouble later on, but less stress for the fish if you can take the photo without laying the fish out. Of course, SOME people will be tempted to put their scale objects much closer to the camera than the fish!
  8. Back when I was up there doing research I would sometimes wade after them with a swimsuit on. Only worked if I got out waist-deep or deeper and had something I could throw a long way, like a bigger Rapala broken minnow. That water is awfully clear most days. And yes, as Ed notes, this was in June. The times I took the canoe out worked out a lot better. There were days when I couldn't miss with a funky white and pink jig that looked like something out of Japanese anime. Door County is crawling with tourists but they are concentrated in the towns. Bring your own food or prepare to shell out major bucks!
  9. Okay good - joke's on me. My father, may he RIP, would in all likelihood have fallen for this... smart people can have weird blind spots. So I never assume. I think the scams are just slightly more believable when the scammer gets your friend's name and/or email from a board and uses that as a false identity. Just slightly. I contacted the US embassy in Manila and asked my congressman to follow up on this. That's why they call them public servants.
  10. Um, to be very delicate about this, I hope everybody realizes this is very likely a scam. Maybe I'm the one to look dumb here but just making absolutely sure.
  11. Pretty hilarious with the sound of the line zipping off the reel. Anybody ever catch a bat or bird on a fly? I've come close on a few occasions.
  12. jhoekstra

    acid rain

    Regulation of coal-fired power plants and smelters led to widespread adoption of scrubbers and lower-sulfur types of coal, reducing sulfur dioxide emissions greatly. It was a type of cap-and-trade type system. Most scientists credit it with heading off the worst impacts of acid rain. There are also regions that are naturally protected from acid rain by limestone bedrock and buffered soils. The main remaining threat are nitrogen oxides that are released by internal combustion engines of every sort and a number of other sources including agriculture. Acid rain isn't "solved" but the trends have been encouraging. Unfortunately positive environmental news is not widely reported, leading to a perception that there's nothing we can do. Here's to sweet cool water. Jon H
  13. Way too green to comment, except to say that I am now the proud owner of some lead eyes that are quite a bit too heavy for my 5-wt rod and line. That's what happens when you have a Bass Pro gift card and try to shop for tying materials there (I got the smallest eyes they had!). I wonder if there would be a way to modify bead chain so that it took on the right weight. Jon H
  14. Kevin, Thanks for the offer! Not sure on sizes: would these work for a tall, skinny 8-yr-old girl? By next Fall I think she will be wanting them. Right now she only wants to fish in the river if it's warm and she can swim through the deep holes Anyway, size permitting, I'd be interested. Best, Jon H
  15. Thanks for the post, Jonn. I emailed him, with the disclaimer that I don't get to fish as much as I would like to, or NEARLY as much as some of you guys in the ISA! ANOTHER point: anybody know of a survey or active study trying to determine the impact of Asian Carp on the smallmouth bass fishery? This upcoming focus group in Peoria is more prospective (what if the carp get into the Great Lakes?). I am talking about a retrospective study of how the fisheries in Illinois have been altered by Asian Carp. I've checked Google / G Scholar and some journal databases but haven't found anything. It's a big deal, and I haven't seen research results yet, but I HAVE read some useful recollections on this board. If there really isn't any research published yet, I would be happy to put together a survey and invite ISA members to at least get a little bit of data together; something's better than nothing! Best, Jon H
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