Register now on PaFlyFish.com! Login
HOME FORUM BLOG PHOTOS LINKS


Sponsors

Browsing this Thread:   1 Anonymous Users





Didymo spreading in Delaware system: latest from DRBC

Joined:
2006/11/10 8:32
Posts: 1758
Offline
Large Blooms of Didymo, aka “Rock Snot,” Discovered in the Delaware River
Anglers are Encouraged to Vigilantly Clean Equipment to Prevent the Spread of this Invader

For Immediate Release

April 24, 2012


(WEST TRENTON, N.J.) -- The Delaware River Basin Commission (DRBC) today announced that a staff scientist last week found extensive mats of the aquatic alga Didymosphenia geminata (also known as Didymo or "Rock Snot"), an invasive species, in the Delaware River.

Dr. Erik Silldorff, an aquatic biologist with the commission, on April 18, 2012, discovered large Didymo blooms in the Delaware River over a 40-mile stretch extending from the area near the confluence with the Lackawaxen River (river mile 279) downstream to the vicinity of Dingmans Ferry Bridge (river mile 239). This section of river includes portions of two National Park units: the Upper Delaware Scenic and Recreational River and the Delaware Water Gap National Recreation Area.

"We knew Didymo occurred in the river," Dr. Silldorff said, "but the spatial extent and intensity of this bloom is alarming given its potentially detrimental effect on ecosystems and the ease in which it can be spread to nearby tributaries."

Didymo covers rock surfaces in cold, moderate to fast flowing water. Since 2007, Didymo has been found at low concentrations during the summer months from around Hancock, N.Y., downstream to the area around Dingmans Ferry, Pa., with high-density patches frequently observed in the cold-water zones of the East and West branches of the Delaware River, as well as in the colder zones of the upper main stem river.

Following the recent discovery, scientists with the National Park Service and the Pennsylvania Department of Environmental Protection over this past week independently documented Didymo blooms extending north of the area discovered by Silldorff to Callicoon, N.Y. (river mile 303) as well as from Long Eddy, N.Y. (river mile 315) upstream into the East and West branches of the Delaware River (upstream of river mile 330). Each biologist noted that the intensity was variable, with some areas having dense coverage, while other sites or locations only having relatively small patches. Regardless, these findings indicate that the blooms of Didymo now extend across more than 100 miles of river.

While Didymo is not a public health hazard, there is great ecological concern with discovering the invasive alga to this extent and in these concentrations. Thick mats of Didymo can crowd out or smother more biologically valuable algae growing on the riverbed, thereby significantly altering the physical and biological conditions within a stream.

Additionally, Didymo can easily attach to any fishing equipment, especially felt-soled boots, and the chance of it hitchhiking its way into nearby streams or rivers that currently lack this unwanted invader is cause for alarm. The risk is compounded by the bloom's timing with the beginning of trout season, when anglers flock to the river in large numbers. This spring's warm weather and low flows are bringing out even more fishing enthusiasts, further amplifying the concern for spread.

DRBC staff is coordinating with scientists from Pennsylvania, New York, New Jersey, and the National Park Service to quickly alert the public and identify appropriate next steps. Samples already collected were sent to the laboratory at The Academy of Natural Sciences in Philadelphia where Academy scientists confirmed the identification of Didymo. Follow-up surveys to determine the actual downstream extent of the bloom are planned once river conditions improve after the weekend's rains.

For more details, including additional information on Didymo and how to prevent its spread by properly cleaning equipment before entering another stream or river, please visit www.drbc.net (see below).

The DRBC is a federal/interstate government agency responsible for managing the water resources within the 13,539 square-mile Delaware River Basin. The five commission members are the governors of the basin states (Delaware, New Jersey, New York, and Pennsylvania) and the commander of the U.S. Army Corps of Engineers' North Atlantic Division, who represents the federal government.



***

Contacts: Kate O'Hara, DRBC, 609-883-9500 ext. 205, katharine.o'hara@drbc.state.nj.us
Erik Silldorff, DRBC Aquatic Biologist, 609-883-9500 ext. 234, erik.silldorff@drbc.state.nj.us

***


Editor's Note: The DRBC uses a stream location and identification system based on river mileage. River mile zero is located at the mouth of the Delaware Bay (i.e., where the bay meets the Atlantic Ocean) at the intersection of a line between the Cape May Light (N.J.) and the tip of Cape Henlopen (Del.). As one moves upstream, river mile 330 is the "head" (or beginning) of the main stem Delaware River, where the East Branch of the Delaware meets the West Branch near the town of Hancock, N.Y. Details can be found at http://www.nj.gov/drbc/basin/river.

Posted on: 2012/4/24 17:31


Re: Didymo spreading in Delaware system: latest from DRBC

Joined:
2011/4/19 4:09
From Elizabethtown
Posts: 163
Offline
say what you want but untill something is developed to kill it there will be no stopping the spread.

Posted on: 2012/4/24 19:34


Re: Didymo spreading in Delaware system: latest from DRBC

Joined:
2007/6/19 21:49
From Lancaster County
Posts: 1541
Offline
There was a recent thread about algae blooms, with speculation that the early warmth and limited leaf growth on trees at the time was allowing algae to temporarily grow. I've attached two photos of algal growth that I took on a small stream - I'm hoping those who have seen didymo can ID it as NOT being didymo...

Its unfortunate, but perhaps inevitable that it has shown up en masse on the Delaware. No matter how conscientious most people are, it only takes one that isn't to spread it.

Attach file:



jpg  IMAG1550.jpg (150.09 KB)
957_4f9743a05b870.jpg 640X383 px

jpg  IMAG1549.jpg (128.92 KB)
957_4f9743b8498d4.jpg 640X383 px

Posted on: 2012/4/24 20:22


Re: Didymo spreading in Delaware system: latest from DRBC

Joined:
2006/9/13 10:18
From LV
Posts: 7749
Offline
What I don't understand is why when it was originally found was it not addressed then?

Posted on: 2012/4/24 21:41
_________________
There is always time to do more to protect wild trout.


Re: Didymo spreading in Delaware system: latest from DRBC

Joined:
2006/11/10 8:32
Posts: 1758
Offline
Once it is found there is nothing that can be done except to slow its spread through angler education (voluntarily or forced, depending upon the state or country). It easily spreads through fragmentation, so if it is found in a river or creek, pieces are already on the move downstream. It is up to anglers to do their part to prevent human caused movement from stream to stream, but nothing can be done about natural transporters of algal fragments.

Posted on: 2012/4/24 22:20


Re: Didymo spreading in Delaware system: latest from DRBC

Joined:
2006/9/10 22:25
Posts: 136
Offline
I've been hearing for years about the dreaded didyno spreading to our streams and ruining fisheries. Well i think its all just chicken little talk. studies have shown no drop in fishery quality in streams/watersheds affected by it. reminds me of the killer bee talk back in the early 80's and how 'soon they be here' i say until its here, don't worry about it, and when it comes, lets see what happens. i mean if you can't stop it, why worry about it? go fish while you can!

Posted on: 2012/4/25 9:01


Re: Didymo spreading in Delaware system: latest from DRBC

Joined:
2011/6/8 8:41
From York, PA
Posts: 82
Offline
Here's a nice little fact sheet from the PFBC:

http://www.fish.state.pa.us/water/hab ... ans/didymo/faq_didymo.htm



Posted on: 2012/4/25 9:13


Re: Didymo spreading in Delaware system: latest from DRBC

Joined:
2008/8/24 20:26
From Mount Joy, PA
Posts: 2234
Offline
Quote:

NJAngler wrote:
I've been hearing for years about the dreaded didyno spreading to our streams and ruining fisheries. Well i think its all just chicken little talk. studies have shown no drop in fishery quality in streams/watersheds affected by it. reminds me of the killer bee talk back in the early 80's and how 'soon they be here' i say until its here, don't worry about it, and when it comes, lets see what happens. i mean if you can't stop it, why worry about it? go fish while you can!


I can't help but find the irony in your post with where you're from... Perhaps that was NJ's environmental policy over the years?

Wouldn't you rather be proactive instead of reactive? To the best of my knowledge, didymo is a proven "stream killer".

Posted on: 2012/4/25 9:42


Re: Didymo spreading in Delaware system: latest from DRBC

Joined:
2006/12/13 9:28
From Other side of the tracks
Posts: 18788
Offline
And just so you know NJ, Africanized honeybees are not coming anymore. They are here (well established in the Southern US, especially Southwest). You aren't hearing about them anymore because Obama photo ops and his appearances on SNL are more news worthy.

They are established in 10 states as of 2010 according to the US department of Ag.

And we all know how quick the Gubermint is to respond to anything. They have to be established before USDA will acknowledge it.

IMO (and I'd guess the opinion of many beekeepers) there are two main things that have slowing their spread.

1. Responsible beekeepers.
2. Bee diseases and parasites killing off both domestic and wild hives.

Several years ago there was a massive die-off of wild bees. In Ohio and PA, about 95% of the wild bees died off. I don't know how this has effected southern wild bees, but I do know all major beekeepers have been struggling with CCD, mites, that weird virus from Australia or Israel, and whatever. I have no reason to believe that wild bees faired any better down south.

The only thing saving the bees (and about 40% 0f the fruits and veggies we eat) right now are hobby bee keepers like myself. Yea, that is opinion too, but somewhat fact based.

If we could only find a disease for Didymo, or for those that spread it.

Posted on: 2012/4/25 14:36
_________________
There are certain pursuits which, if not wholly poetic and true, do at least suggest a nobler and finer relation to nature than we know. The keeping of bees, for instance." -Henry David Thoreau--


Re: Didymo spreading in Delaware system: latest from DRBC

Joined:
2011/11/5 14:27
From MidAtlantic
Posts: 322
Offline
The rock snot is so bad in the upper section of the GunPowder this year that it is basically impossible to fish a wet fly, but it is nothing compared to what I saw in the South Holston last year where huge globs of the stuff were floating everywhere.
Apparently the algae has always been with us in the sub-artic regions, but about 10-12 years ago a new more adaptable strain of it showed up on Vancouver Island and has spread from there. From what I can find it has no natural enemies and no one has a good solution for eradicating it. You can only try to prevent it's spread.

Posted on: 2012/4/26 9:52


Re: Didymo spreading in Delaware system: latest from DRBC

Joined:
2012/4/8 10:21
From Perkasie, PA
Posts: 101
Offline
Quote:

salmonoid wrote:
There was a recent thread about algae blooms, with speculation that the early warmth and limited leaf growth on trees at the time was allowing algae to temporarily grow. I've attached two photos of algal growth that I took on a small stream - I'm hoping those who have seen didymo can ID it as NOT being didymo...

Its unfortunate, but perhaps inevitable that it has shown up en masse on the Delaware. No matter how conscientious most people are, it only takes one that isn't to spread it.


Its a diatom a unicellular algae.
Multiple methods of reproduction:
Vegetative: since they have a silicon shell, the daughter cell is smaller. Its like the Matryoshka doll in physical terms.

sexual: formation of auxospores allows for the daughter to regain its size as compared to the parent cell.

The shells of dead diatoms are the source for diatomaceous earth you put in pool filters and such

Scientific nameof Didymo is : Didymosphenia geminata

Here is a site with good images. If you have a microscope, you will be able to ID the cells at high power (400X) easily. Though many of the images were taken with a SEM, a light microscope is enough to Id.

Click on the autecology tab to see images more like those you would see in a light microscope.
diatom site


If you don't have a microscope and want to know send my a sample. I can verify the species.

I'm no expert but I am a bio major!

Posted on: 2012/4/26 13:23


Re: Didymo spreading in Delaware system: latest from DRBC

Joined:
2012/2/27 15:04
From Perry County
Posts: 80
Offline
Proactive is better than reactive by far with this stuff. I think that we as these streams users and caretakers need to spread the word about responsible care of waders and boots. Start teaching the new fly fishers and all anglers as well as those of us who have been at it for a while to use some common sense about cleaning up when we are done fishing.

See many of us on this forum travel to fish but in general the guys I run into in perry county, the average angler, really don't. They fish the same streams year after year and think as long as it isn't here we don't have a problem. That attitude is probably the same in most areas.


Posted on: 2012/4/26 14:34
_________________
"I am only after the dumb ones"


Re: Didymo spreading in Delaware system: latest from DRBC

Joined:
2009/2/11 13:14
From Lehigh Valley
Posts: 1269
Offline
Ialways worried about spreading Zebra mussels , since i do a bit of ?Flyfishing where they are/were prevalent.i used to come home an soak my studded felts in light bleach water an then dry em out good before wearing my boots again...
i know quite a few of my fishing buddies that have seen Didymo on the Delaware.
i hope theres a way to eradicate it responsibly.
Tight Wraps & Tight Lines
Rick Wallace

Posted on: 2012/4/26 14:44


Re: Didymo spreading in Delaware system: latest from DRBC

Joined:
2006/9/10 22:25
Posts: 136
Offline
Well if you r really worried, I say use different pairs of waders -alternate using them so that one pair is completely dry before use again. Or simply stay out of the water. On many of the smaller waters I fish wading is not necessary and you can stick to one side and/or cross using rocks or logs.

i think that it could be that waterfowl themselves(herons/egrets/mergansers et al) or even mammals that are the biggest transporters of it to new areas. check out the shoreline of any stream and you see dozens of animal tracks.

Over here in NJ we have a water chestnut issue in our ponds/lakes. nasty stuff that creates thick mats making fishing impossible. they tried harvesting it but the root(where the chestnut is) remains anchored in the lake bottom so it just grows back. anyhoo, waterfowl are the primary guilty party flying around and carrying the seeds with them to other ponds and lakes. it can spread to an acre in less than 3 years.


It also seems like the faster(steep grade) the water, the less dense the masses are so even if headwater streams get infected, it may only be at nuisance levels and not catastrophic levels many fear. I think any sig. rainfall will break it apart(like you see with regular algae). If anything its the lower gradient, smallmouth waters like the D that will be most affected. hey if it keeps all those annoying boaters and canoeists off the river, so much the better!(there is always a bright side)

Posted on: 2012/4/28 8:09

Edited by NJAngler on 2012/4/28 8:24:38






You can view topic.
You cannot start a new topic.
You cannot reply to posts.
You cannot edit your posts.
You cannot delete your posts.
You cannot add new polls.
You cannot vote in polls.
You cannot attach files to posts.
You cannot post without approval.

[Advanced Search]





Site Content
Login
Username:

Password:

Remember me



Lost Password?

Register now!
Stay Connected

twitterfeed.com facebook instagram RSS Feed

Sponsors
Polls
Will you be fly fishing this autumn?
Yes
No
Thinking about it
_PL_TOTALVOTES
The poll will close at 2014/10/31 17:56
1 Comment





Copyright 2014 by PaFlyFish.com | Privacy Policy| Provided by Kile Media Group | Design by 7dana.com