Didymosphenia geminata, an Obnoxious Colonial Diatom in our Streams

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Didymosphenia geminata, an Obnoxious Colonial
Diatom in our Streams

• Russ Rhodes
• Department of Biology
• Missouri State University
• Springfield, Missouri

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I would like to acknowledge Mr. Robert Britzke
from Eureka Springs, Arkansas for pointing out
the presence of Didymosphenia geminata in the
tail race area of Beaver. Numerous collections
were made from a variety of sites in March 2003
followed by March- May 2006. Many of the images
in this talk were made at those sites and from
the collected material.
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Whoa there, whats this?

• Animal?
• Plant?
• Mineral?

The Blob!!!
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The Blob (more commonly referred to as rock snot
or Didymo) in Arkansas
The brown color is due to fucoxanthin, a pigment
contained in each cell, (although each cell also
contains chlorophyll) and the white or
translucent color is due to the stalks.
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Plan

• What is Didymo?
• Where is it currently found?
• What are its positive effects?
• What are its negative effects?
• What can be done to control Didymo?
• Open discussion

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What is Didymo?

• Didymo is a colonial diatom.
• Major characters are
• Silicon wall with precise ornamentation
• Oil and carbohydrate for storage product
• Each cell exudes extracellular polymeric
  substance, EPS,the material of stalks and
  resistant to degradation.
• There are phosphatases at the base of each cell
  where new stalk material is extruded.
  Phosphatases remove PO4 from organic phosphate
  molecules.
• When cells divide, the stalks are formed anew but
  connected to the old stalk. Thus the stalk
  material continues to build up.

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Didymosphenia geminata

• Colonial diatom
• Cells divide
• Attachment as gelatinous stalks
• Massive plant
• Cells (200-300 microns)
• A cell cleaned in sulphuric acid and showing the
  ornamentaion critical for identification

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Diatoms, Food for Scud
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Below are both a cell and stalk of Didymo found
in the gut content of Gammarus which was living
in the stalk portion of Didymo at the time of
collection. Didymo is not known to produce any
toxins and the oxygen content within the stalk
matrix has been found to be supersaturated.
A Gammarus found in a colony of Didymo
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Microscopic colony of Didymo scraped from a rock
in the Beaver tailrace, March 2006 The ability of
Didymo to remain attached to the substrate by the
basal portion of the stalks probably contributes
to its continued presence and redevelopment after
a flood type event and/or seasonal changes. (1)
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(No Transcript)
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Gomphonenma with stalks and division similar to
Didymo. The major difference is that the stalk
material of Gomphonema is slippery and that of
Didymo is cottony.
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Where is it currently found?
A site downstream from the tailrace region of
Beaver as well as other locations in the tailrace
region. Russ Rhodes and Bob Britzke are
collecting at this site, March 2006.
World wide, from Canada to China to New Zealand
to England. In many states from Maine to the TVA
region to New Mexico to Arkansas to the NW
New location in Maryland (18) Someone who
fishes the Gunpowder is likely to fish the Savage
or Big Hunting Creek," Cosden said. "That's been
the pattern. The better trout streams is where
it's showing up."
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Conditions most favorable to Didymo colonization

• High N/P ratio, low phosphorus (lt 2 ug/L) in the
  water.
• Bright sunlight
• Low TSS (total suspended solids)
• pH (7-9)
• Generally cold waters, but found in waters from 4
  to 27 C (2)
• Stable water flow mean flow regime is
  associated with bloom development, based on a
  significant negative relationship detected
  between D. geminata biomass and mean discharge
  (3)

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Additional conditions found associated with Didymo

• High biomasses found in the tailrace areas and
  streams below impoundments
• Important predictor variables of D. geminata
  abundance included dam presence, water clarity
  and total phosphorus concentration. When data
  from dam sites were analyzed, a multiple
  regression model using mean discharge and pH as
  independent predictors explained 73 of the
  variation in D. geminata cell density. Analysis
  of 3 years of data from one study river (Red Deer
  River) revealed consistently higher D. geminata
  cell densities at the dam site compared to the
  upstream reference. (4)
• Even after flooding the tailrace area within a
  week biomass of Didymo returned to pre-flood
  amounts (5)
• Presence in an Alaskan lake (Lake Naknek) from
  sediment record (1218-2003) (11) indicating that
  this organism is not new to North America

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What are its positive effects?

• The stalks provide additional substrate for
  epiphytic diatoms such as Eunotia seen here.
• The cells are a source of food for invertebrates
  such as scud, as seen in a previous slide.
• During the day the cells provide an additional
  source of oxygen to the water through
  photosynthesis.

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What are its negative effects?

• The damage caused by Didymo is largely from the
  stalks produced by each cell of the diatom colony
  which form large mats on streambeds, decreasing
  clarity and oxygen availability (especially at
  night). In some areas mats 20cm thick have been
  reported. (6)
• When Didymo is absent or in low numbers,
  diversity of invertebrates is increased .(6)
• Significant changes in the kinds of invertebrates
  were found in an excellent study by EcoAnalysts
  Inc. (12) in examining the effects of Didymo in
  the Kootenai River, Montana/Idaho
• EPTs declined (Ephemeroptera (mayflies),
  Plecoptera (stoneflies), and Trichoptera
  (caddisflies)),
• mats were a haven for midges and worms (12)
• Another study on the negative effects of Didymo
  was undertaken by Erica Shelby of the Akansas
  Departent od Environmental Quality (26). She
  found decreases in the biodiversity of
  invertebrates associated with populations of
  Didymo.
• In New Zealand D. geminata has been correlated
  to increases of invertebrates that are indicators
  of poor stream health. (7)
• Canals used for irrigation and aquifers in
  California are scraped of Didymo. It also clogs
  grates in the water supply canal. (2)
• The stalks create a very unsightly looking
  benthos on the stream and on the shore where they
  dry resembling toilet paper.

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What is being done to control Didymo?

• Models One approach is to develop models that
  may predict the distribution of Didymo based on a
  sorting of habitats by air temperature, base
  water flow, precipitation seasonality, and other
  parameters. The former two seem to be able to
  account for much of the variance (10)
• Phosphorus In an attempt to manage around an
  infestation of Didymosphenia geminata South
  Dakota GFP is starting a nutrient-enrichment
  project this spring that involves artificially
  increasing total phosphorus in a 3-kilometer
  section of Rapid Creek immediately below Pactola
  Dam. The goals of this project are to stimulate
  productivity, both primary and aquatic insect,
  and to ultimately increase brown trout growth and
  survival. (8) Didymo may be able tolerate low
  or limiting P since it can produce phosphatases
  as mentioned earlier.
• Another study on phosphorus uptake in a low
  concentration by Didymo implicates the
  enhancement of P uptake by the presence of iron
  (15)
• Copper In New Zealand, a copper compound Gemex_at_
  is being used to control the growth of Didymo.
  Final field trial results show positive effects
  of reducing growth of Didymo in applications in
  New Zealand. (13)
• Mucinex Another new approach has been tried in
  2009. It involves the application of mucinex, an
  off the counter mucous loosener. (15) (16)

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What else is being done!!

• DNA testing One of the latest techniques to
  assess the presence, low density, and then
  aggressive public awareness (to follow) and other
  techniques is a DNA screen (19)
• Regulating stream flow The findings suggest
  that controlled flow releases from reservoirs
  during the summer could be used to limit the
  impact of this nuisance species in streams in the
  Colorado Front Range. Flows below Barker
  Reservoir near Nederland that are above 200 cubic
  feet per second similar to those experienced
  last year once the reservoir started to spill in
  late June appear to be sufficient to control
  the didymo (20)
• Scouring Our results suggest that bed movement
  may be a dominant scouring mechanism that acts to
  control the growth and distribution of D.
  geminata. (5)
• Cleaning after fishing There have been a number
  of resources published that focus on clean up.
• One of the most thorough is http//www.westdenver
  tu.org/snails.htmcleaning (21)
• A well recommended chemical cleanup is best
  described as follows I recommend Uncle Jacks
  Didymo Cleaner  to ensure a 100 clean kill of
  all didymo cells. (22) It is a formulation of
  benzalkonium chloride (24)
• Uncle Jacks Didymo Cleaner This is the
  reference to the cleaner and source of purchase
  (23). It was tested by NIWA (National Institute
  of Water and Atmospheric Research, New Zealand.
• Public awareness While not an algicide, nutrient
  enhancement, nor flow control, many states have
  developed awareness programs through website,
  posters, and talks such as this to create a
  public awareness tuned to the prevention of
  spreading Didymo from one habitat to another.
  One of the main culprits in this spread is the
  felt sole of waders. Examples of posters are as
  follows

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http//www.fish.state.pa.us/water/habitat/ans/didy
mo/faq_didymo.htm
http//www.anr.state.vt.us/dec//waterq/lakes/docs/
ans/lp_dididguide.pdf
Disinfect your boat, trailer, boots other gear beforeentering a new body of water
Remember -- you cant see individual didymo cells -so thoroughly disinfect all of your equipment

                    Photo - Tim Daley, PA DEP
CHECK -- Before you leave a river, stream, or lake, check items and leave debris at site. If you find any later, treat and put in trash. Do not wash down drains. CLEAN -- There are several ways to kill didymo. Choose the most practical treatment for your situation which will not adversely affect your gear.
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Missouri Department of Conservation
http//www.wildlife.state.nh.us/Fishing/Fishing_PD
Fs/DidymoPoster_07.pdf
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Videos and images on the web about Didymo

• Images http//images.google.com/images?hlensour
  cehpqdidymoum1ieUTF-8eiAbhHS4KtOoi4M5fU2I
  8JsaXoiimage_result_groupcttitleresnum4ve
  d0CCcQsAQwAw
• Videos
• http//www.biosecurity.govt.nz/video/didymo-effect
  s-waterways Rather dramatic
• http//www.invasivespeciesinfo.gov/aquatics/didymo
  .shtml
• http//www.dgif.virginia.gov/fishing/didymo.asp
  great for stream coverage measurements
• http//www.wchstv.com/newsroom/wvwildlife/2009/ww0
  90520.shtml

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Conclusion What about Trout?

• In a study of trout in Rapid Creek, South Dakota,
  the brown trout were stuck with 1 yr or less age
  fish, with no second year and very few adults
  since Didymo was first reported in 2002. This
  stream was one of the top two brown trout
  fisheries in the state in 1990s.This impact
  appears to be due to Didymo altering the aquatic
  insect community and thus impacting the food
  source for the trout. (8)
• The relative weight of brown trout below Bull
  Shoals dam in November 2006 was the lowest that
  has ever been recorded. Relative weight for both
  brown and rainbow trout have been falling in Bull
  Shoals tailwater since 2004, which coincides with
  the appearance of Didymo. This decrease in
  relative weight has been documented in other
  trout waters around the world where Didymo has
  occurred. (14)

We need to be 1. Surveying likely locations of
Didymo 2. Utilizing posters and other
information regarding the hazards of not cleaning
fishing equipment 3. Spreading the word of the
potential impact of a Didymo bloom on the
fisheries
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References

• Whitton B, Ellwood N, Kawecka B. Biology of the
  freshwater diatom Didymosphenia a review.
  Hydrobiologia serial online. September
  2009630(1)
• http//epa.gov/Region8/water/didymosphenia/White2
  0Paper20Jan202007.pdf Spaulding, S and L.
  Elwell (2007)
• Kirkwood, A. E., S. Troina, L. J. Jackson, and E.
  McCcauley. 2007. Didymosphenia geminata in two
  Alberta headwater rivers an emerging invasive
  species that challenges conventional views on
  algal bloom development. Canadian J. Fisheries
  and Aquatic Sciences 641703-1709.
• Floeder S, Kilroy C. Didymosphenia geminata
  (Protista, Bacillariophyceae) invasion,
  resistance of native periphyton communities, and
  implications for dispersal and management.
  Biodiversity and Conservation serial online.
  December 200918(14)
• Miller M, McKnight D, Cullis J, Greene A, Vietti
  K, Liptzin D. Factors controlling streambed
  coverage of Didymosphenia geminata in two
  regulated streams in the Colorado Front Range.
  Hydrobiologia serial online. September
  2009630(1)
• http//ecosystem-preservation.suite101.com/article
  .cfm/didymo_freshwater_diatom
• http//wildlife.utah.gov/pdf/AIS_plans_2010/AIS_12
  bDidymo-Dan-final.pdf
• http//www.ncd-afs.org/Pages/59/RSTC20State20Rpt
  202007.pdf
• http//www.niwa.co.nz/news-and-publications/publi
  cations/all/abb/2006-19/copper
• Sunil Kumar, Sarah A Spaulding, Thomas J
  Stohlgren, Karl A Hermann, Travis S Schmidt,
  Loren L Bahls (2009) Potential habitat
  distribution for the freshwater diatom
  Didymosphenia geminata in the continental US.
  Frontiers in Ecology and the Environment Vol. 7,
  No. 8, pp. 415-420.
• Pitte, D. P, K. A. Lane, A. K. Hermann, S. A.
  Spaulding, B. P. Finney. 2009. Historical
  abundance and morphology of Didymosphenia species
  in Naknek Lake, Alaska. Acta Bot Croat
  68183-197.

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References (continued)

• http//www.amaab.org/images/1510_Lester_Effects_of
  _the_Nuisance_Diatom_
• 13.http//www.niwa.co.nz/news-and-publications/pub
  lications/all/abb/2007-25/didymo
• 14. http//www.hoaff.org/newsletters/NL2007-04.htm
  
• 15. http//www.asee-nc.org/Conferences/Spring08Mee
  ting/Srping08Proceedings/pdf/set2/71.pdf
• 16. http//www.flyfishnewengland.com/didymos-study
  .htm
• 17. http//www.mucinex.com/
• 18. http//articles.baltimoresun.com/2009-12-17/sp
  orts/0912170014_1_didymo-trout-waters-fishing-
  gear
• 19. http//www.waikato.ac.nz/news/archive.shtml?ar
  ticle627
• 20. http//coyotegulch.wordpress.com/2009/05/11/la
  rge-instream-flows-help-control-didymo
• 21. http//www.westdenvertu.org/snails.htmcleanin
  g
• 22. http//www.chrisdore.com/whattobring.htm
• 23. http//www.unclejacks.co.nz/1.htm
• 24. http//www.fs.fed.us/r4/resources/aquatic/lite
  rature/matthews_quat_disinfectants_ didymo.df
• 25. http//www.unclejacks.co.nz/4.htm
• 26. Shelby, E. L. 2006. An Assessment and
  Analysis of BenthicMacroinvertebrate Commumities
  Associated with the Appearance of Didymosphenia
  geminata in the Whitw River Below Bull Shoals
  Dam. ADEQ Final Draft. 42 pages.

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Thanks for having me!

• Several of the photos were courtesy of Scott
  Branyan and Bob Britzke