More on Crawfish

[Jeff Furber]

In the recent posts on crawfish on Winnie, I came across an article about them. This info was provided by a US Dept of Interior biologist, who was doing his masters thesis on freshwater crawfish: here are some of the highlights, major crawfish activity begins when water temps reach about 50degs, probing rock crevises for females,depending on rising water temps. Crawfish are light sensitive, water clarity and penatrating sunlight are key ingredients.
After mating females burrow into holes or caves, the males "molt" and quickly hide. After the "molt" the males return to their reclusive habits, after the molt they often change color.
The females eggs hatch in 30days or so, again depending on water temp. Once the young leave the female, she too, goes into a low light feeding cycle like the males.
During summer growth periods, young crawfish are more at threat due to bottom feeders, ie chubs and other species, as they try to hide in small rock crevices.
As the article states much of the life and activitys of a crawfish depends on water temp, water clarity, when the water temp is up they are active, when it drops below 45degs they are less active.
Like all creatures of nature,crawfish want to eat,mate and protect themselves from predators. Actions of crawfish depend on their location as northern craws may and do act differntly than their southern cousins.

I am relating this article not as a final word on crawfish but to show the many varied activities of them and perhaps help explain why the crawfish population may increase or decrease depending on each different year.

[RUSTY BEAR]

There are several species and sub speices of Crawfish aka Crawdads in various parts of the country and translocating them has caused havoc in some areas for example the southern red one out competes the locals in Wisc and Minn but the fish prefer the locals thus causing some disruptions in the normal food chain. The great outdoors is a wonderful but sometimes delicate place. Barney Bear and I are going to check out the environment in Hawaii for a month- please try to have the ice out for us when we get back.:)

[madrasahs]

"I am relating this article not as a final word on crawfish but to show the many varied activities of them and perhaps help explain why the crawfish population may increase or decrease depending on each different year."

Nice article -- thanks for posting it.

For decades, we used to search the shoreline rocks for bait crawfish. Over a short period of years, they practically disappeared from the shore and the traps -- and haven't returned in the last thirty years. (Not a temporary decrease on a different year). Insect larvae appear to be a far more common find under those very same rocks today.

An occasional crawfish can be seen here drunkenly moving along the shoreline, flipped about by the (now) season-long wave action.

Anecdotal posts on this forum indicate that crawfish are diminished from Winnipesaukee's southern habitat, but are "abundant" in Winnipesaukee's northern habitats.

Is there a connection with the basketball-sized mounds of lake "suds" that appear after strong September winds blow in from Meredith-direction?

Is it shoreline silting-in from season-long wave action?

Is water quality better (for crawfish) in northern Winnipesaukee?

[michaelmcd]

my theory on the lack of crawfish is the modernization of all the homes, specifically the removal of septic tanks.
We have our summer house in wolfeboro bay, when i was a kid i used to catch cray fish by the bucket full for bass fishing. about 10 years ago the town came down the street and most everyone connected to the sewer line and removed the septic tanks and leaching fields. shortly after that most of the water along the shores started to get clearer, our neighbor to the left however did not see the need to spend money and connect. for the next few years the water on the left of our dock was a bit more murky in color than the water to our right, coincendently, i could still find crawfish in the rocks in that area. eventually (about 6 years ago) the neighbor went to sell the house and was forced to dig up the septic / leaching and connect to the town sewer. once again, coincendently, the water is clear as glass, and it is very hard to even find a crawfish.
Im not an expert on crawfish, but my observations lead me to believe those little fella's thrived on the "sewage" everyone used to let run off into the lake.

[Mike J.]

Although some subspecies are partial to muddy waters, all crayfish are extremely sensitive to chemicals and nitrates. Wave action only effects them when they are near to shore, which is generally only at night, and the water is generally pretty calm then. But their eggs will simply not hatch in waters that are at all polluted. The biggest problem for crayfish, and for so many other things about Lake Winni's waters, is the increasing use of lawn fertilizers and lawn treatments within the watershed. These pollutants are destroying the lake and killing everything in it. The Shoreland Protection Act, which only regulates lawn care within 50 feet of the shore and is barely enforced anyway, does not address the big problem. The insecticides and weed killers applied to lawns in Grouse Point or Gunstock Acres, or even around the Castle, do not break down for years and quickly make their way into the lake. Since Winni's abundant crayfish population was the reason that smallmouth bass thrived here after being introduced, it follows that the decline of crayfish is a big part of the reason that these bass are now so much smaller and scarcer. In a balanced ecosystem, the fish weights will be more varied from lunkers to juveniles. Winni now has an abundance of midsized bass that cannot get any larger due to the lack of that protien source (and the pressure of fishing tournaments). If you want to do something to save Winni...fight the real enemy...lawns. Plant twenty trees in the watershed and save a fish.
Mike

[loudon resident]

I wonder how the "light pollution" along the shoreline affects them? Any students out there looking for a thesis project?

[Cablebob]

I have fished for smallies for nearly 40 years.
And I agree that the crawfish population has sharply declined. However it's my findings that the size and amount of the fish caught goes in cycles.

I fish the same week in June.
We have a mini contest and log each fish (over 12") caught. About every 4 or 5 years we see 4+ lbs. and loads of 2-3 lbs. on off years we only see 1-2 lbs.
like I said it's my experience that the size and amount tend to run in cycles. Last year we caught 117 smallies, nothing over 3 lbs. The year earlier was worse, so I expect to see some 3-4 lbers this year. We still see 1/2 digested crawdads when we flip the grisket to remove hooks.

Now if my Dad can only join the 4 lb club his life would be complete.

But please, if someone could only answer my 7 year old sons question " Daddy, how come there's only crawdaddies and no crawmomies or crawbabies??"

P.S. all fish returned to water with less then 1% mortality rate.

Also note I fish "Up Stream" from Winni.

[Grant]

In 30+ years of fishing the lake and trapping crayfish in our boathouse, I've noticed slight fluctuations in the population. Usually it's a matter of water temp and depth. But we always have a healthy population. We do quite a bit of snorkeling along the shore, and flip rocks to find crayfish. Some years, there are definitely more than others.

As for bass, I definitely don't catch as many off the dock as I used to, but I've seen many of them while scuba diving around the lake. Not quite as many BIG bass, but a fair number of them. I remember back in the early '80s when my cousin and I each nabbed smallies in the 5-pound range one spring. Since then, I've *seen* a few that might've approached that size, but haven't caught anything close to that size.

Meanwhile, down here in PA, the largemouth are plentiful and big!

[Joe Kerr]

But please, if someone could only answer my 7 year old sons question " Daddy, how come there's only crawdaddies and no crawmomies or crawbabies??"

Your 7 yr old is not alone. Others have pondered that very same question. I found an article that explains it. It is an informative and a bit tounge in cheek. Here's an excerpt:

"...Like crawdads for instance. If crawfish are all dads, then how does the species reproduce without any crawmoms?..."

Bottom line is that it seems these are all nicknames for crawfish or crayfish. So Crawdads is not the real name for these creatures.

Anyone remember the old Beverly Hillbillies episode with Granny and the smoked crawdads? Hippies thought the Hillbillies acted the way they did from smoking crawdads and they wanted to smoke some too. Way funny. Anyway, check the article linked below.

Joe Kerr




CrawFish (not Crawdads) (http://www.thenichollsworth.com/news/2001/04/26/Lagniappe/Crazy.Little.Mud.Creatures.Called.Crawfish-73221.shtml)

[madrasahs]

From the responses (Alton/Echo Point, Wolfeboro, Mink, E. Rattlesnake) it seems that crawfish are "MIA" from the south/southeastern 1/3 of Winnispesaukee.

One respondant suggested it was lack of Town sewer service. That doesn't explain our shoreline's lack of crawfish -- our shoreline has only changed in one way (two new lawns in 1980 -- another in 1991), and we're still a mile from the nearest Town sewer line -- after 50 years. (And we've turned over a lot of rocks in the last 30 years).

Another suggested lawn fertilizer. That increase in nitrates and phosphorus could explain our damaged crawfish habitat. Though there has been a lot of washing-out (due storms) of driveways/Title V septics and weekend silting from wave action in the last fifteen years.

I like the suggestion regarding a study/thesis of suburban night lighting. (But usually that results in more activity -- not less. Plant two trees in your front yard. The one nearest the streetlamp grows larger).

I've learned that "crawfish/crawdads" is Southern-talk, and we have crayfish "up North".

But "Crawmoms" always existed. You can flip over any crayfish and determine that for yourself. (I mean "craymoms").

Now I've got to check out if crays are really "aquatic insects".

[GWC...]

***** "crawfish/crawdads" is Southern-talk *****

So is "mud bugs" - perhaps they are aquatic insects...

[loudon resident]

Trees might grow better with an artificially lengthened photoperiod but that doesn't necessarily translate to animal life. I believe one of the first posters mentioned that crawfish were photo-sensitive and therefore only came out to feed at night. If you artificially light the shoreline would they fail/refuse to come out to feed? If so, they could starve or simply fail to reproduce. Option two would of course be that they travel to someplace with out lighting. Again just a theory for any bored grad student out there to play with.

And yes, I believe that the crawfish is in the same family as the lobster which I believe puts it in the same family as the cockroach, a bug.

[winifisherman]

I once heard a theory that changes in the water's pH can effect crawfish populations. Anybody else hear that too?:confused: