Final Report for Grant Agreement WRCP-12451 Diatom Communities in State Parks in Southwestern Pennsylvania

Marina Potapova

1900 Benjamin Franklin Parkway, Philadelphia, PA

Phone:215-405-5068

June 27, 2014

Abstract

The goal of this project was to inventory the diatom flora of State Parks located in southwestern

Pennsylvania. For the last few years this region has been experiencing a rapid increase in natural gas production. Protecting the health of lakes and rivers is an issue of growing importance in shale gas regions and documenting the current state of the aquatic biota is crucial for any future assessments of human impacts. The diatoms play a major role in aquatic ecosystems and are sensitive and widely used indicators of water quality. Collecting baseline data on the composition of diatom communities in State Parks in southwestern Pennsylvania is an important step towards monitoring environmental health in the region. 153 diatom samples have been collected from in various habitats, such as streams, lakes, and wetlands in twelve State Parks.

The diatoms were identified using light and scanning electron microscopy. A total of 451 diatom taxa were documented in studied water bodies. Two diatom species new for science were discovered; one of these species is likely an Appalachian endemic. The invasive species

Didymosphenia geminata was found in Youghiogheny River (Ohiopyle SP), but it did not form severe blooms impairing river ecosystem. A number of water bodies are characterized by diatom assemblages indicative of moderate to severe impairment such as nutrient enrichment or acid mine drainage.

Figure 1. Location of 103 diatom sampling sites in State Parks of Southwestern Pennsylvania.

Objective

Collecting baseline data on the composition of diatom communities in State Parks in southwestern Pennsylvania is an important step in monitoring environmental health in the region.

These data will be useful for future comparisons and impact assessments. They contribute to the knowledge of diatom flora of Pennsylvania and will reveal habitats containing rare, endemic, and possibly invasive diatom species. This work also identifies water bodies with degraded biota and impaired water quality.

Justification

This project belongs to the category of the baseline surveys of aquatic species in State

Parks within the shale gas region. Southwestern Pennsylvania experienced especially fast industrial and agricultural development from mid-1800s to 1950s. The aquatic ecosystems of this of this region were affected by logging, mining, and steel industry. In the last 50-60 years the impact of the industries significantly lessened and many watersheds recovered to various degrees. Many areas are now protected, and a number of State Parks have been established. In the few recent years, the region, however, became one of the “sweet” spots of the shale gas production (MSAC 2011). Although no gas wells are currently drilled in the Pennsylvania State

Parks, their biological communities may still be affected by the drilling and natural gas extraction in surrounding areas. On the other hand, lack of direct impact makes it possible to consider the Parks as refugia where flora and fauna are relatively sheltered from the negative influences.

Diatoms are eukaryotic microbes that are important indicators of environmental health in aquatic ecosystems (Stoermer & Smol 1999). Diatoms possess ornamented silica walls or frustules, which are left behind after the death of the organism. These frustules accumulate in lake sediments and serve as an indispensable tool in reconstructing changes in climate, water quality, and the history of the watersheds. Diatoms are extremely sensitive to changes in ion concentrations, pH, suspended sediment, nutrients, and dissolved organic matter. The high diversity of diatom communities and presence of native and endemic species are indicative of good-quality or undisturbed aquatic ecosystems. Together with fish and benthic macroinvertebrates, diatoms are used by many State and Federal environmental agencies to assess water quality in rivers, lakes, and wetlands (e.g. Potapova & Carlisle 2011). The quality of

4 these assessments depends on the knowledge of regional diatom floras and ecological responses of individual species and communities to a variety of environmental stressors.

Collecting baseline data on the composition of diatom communities in State Parks in southwestern Pennsylvania is an important step in monitoring environmental health in the region.

These data will be useful for future comparisons and impact assessments. They will contribute to the knowledge of diatom flora of Pennsylvania and will reveal habitats containing rare, endemic, and possibly invasive diatom species. Another goal of this work is to identify water bodies with degraded biota and impaired water quality.

Our previous work in north-central Pennsylvania supported by WRCP showed that diatoms of the State are still poorly known (Potapova 2010). From 310 samples collected in 2009 we found several diatom species new for science. Five of these have been already formally described, while the descriptions of several others will be published in the nearest future

(Potapova 2011a,b, 2012, Enache & Potapova 2012). These new species and several other taxa found in north-central region are possible endemics of Pennsylvania or Eastern North America and are have a high value as indicators of good habitat quality. Such data are important for understanding biogeography of diatoms and other protists and ultimately, for developing better methods of biological assessment and monitoring. There were no diatom surveys in southwestern

Pennsylvania focused on taxonomic treatment of the flora and we can expect that the proposed study will yield at least some discoveries of new species or rare species occurrences.

Methods and Materials

153 diatom samples have been collected from 103 locations in various habitats, such as streams, lakes, and wetlands in twelve State Parks (Figure 2, Table 1). Diatom samples were hand-collected from near-shore benthic habitats; a few phytoplankton samples were collected using plankton net. Basic water quality (pH, conductivity) was measured in the field (Figure 4).

GPS coordinates were recorded. In the laboratory samples were treated by nitric acid to remove organic matter. The samples were rinsed 6 times with distilled water. The diatom slurry was used to prepare permanent diatom slides using the Naphrax mounting medium and stubs for the electron microscopy. The diatoms were identified to species level using historical (Patrick &

Reimer 1966, 1975) and contemporary floras (Krammer & Lange-Bertalot 1986, 1988, 1991,

2004) and many others.

Products delivered in addition to this final report

A database containing all the results of this study is delivered to DCNR in addition to this report. The database contains 2 tables and one query:

1) tbl_Samples is the list of all samples collected in the course of this project together with

information on collection sites with geographic coordinates, sample type (substrate) and

environmental characteristics, such as conductivity and pH.

2) tbl_Counts is the list of all observed taxa in each sample together with semi-quantitative

abundance value given on the scale from 1 (rare) to 5 (very abundant).

3) qry_taxa is the list of all diatom taxa observed in the studied samples together with

number of occurrences (number of samples in which species was found) and average

abundance value.

Figure 2. Collection of diatom samples by scraping rocks, Youghiogheny River, Ohiopyle SP.

Figure 3. Collection of plankton samples with net, Laurel Hill Lake, Laurel Hill SP.

Figure 4. Measuring pH and conductivity in the field, Kooser Run. Kooser SP.

Results and conclusions

Measured conductivity and pH for the majority of water bodies indicated were within levels typical for Pennsylvania. However, several creeks had clearly elevated levels of conductivity above 500 and even above 1000 S/cm, obviously a legacy of previous mining activities. Some reservoirs and ponds, such as Lake Arthur and Yellow Creek Lake, had extremely high pH at the time of sample collection. These high pH values were caused by the intensive photosynthesis. For instance, in Lake Arthur, a considerable bloom of planktonic cyanobacteria (Gomphosphaeria sp.) was observed (Figure 5).

Figure 5. Bloom of planctonic cyanobacteria in Lake Arthur, Moraine SP, September 20, 2013.

All 153 samples have been analyzed in the laboratory. A total of 451 diatom taxa were found (Table 2, see also attached database). Some diatoms could not be identified with certainty to species level using existing floras. Two of these diatom species formed large populations and were sufficiently abundant to establish that they indeed represented new species. One of these

Figure 6. A new diatom species tentatively named Encyonema appalachianum, discovered in Western Pennsylvania in summer 2013. 1-6: light microscope images, scale bar = 10 m; 7-10: scanning electron microscope images.

10 species, tentatively called Encyonema appalachianum (Figure 6), is likely an Appalachian endemic. It was found in Youghiogheny River and its tributary Meadow Run (Ohiopyle SP,

Figure 7), Laurel Hill Creek and Lake (Laurel Hill SP), Yellow Creek Lake and Little Yellow

Creek (Yellow Creek SP), McCune Run (Keystone State Park), Big Spring Reservoir (Laurel

Ridge State Park), Lake Arthur and its tributary Muddy Creek (Moraine SP), a tributary to

Slippery Rock Creek (McConnell Mill SP), and Traverse Creek (Raccoon Creek SP). A manuscript formally describing this species has been submitted for publication and is currently in review.

Figure 7. Meadow Run, Ohiopyle State Park, one of the locations where the new species Encyonema appalachianum was found.

Another species new for science belongs to the genus Navicula (Navicula sp. 4 in Figure

8). It has been as well studied in detail and its formal publication is in preparation. This species has been also recently observed in eastern Pennsylvania and it is not clear at this point why it has not been detected before.

Figure 8. Light microscope images of several Navicula species that did not fit descriptions of any published species and may represent species new for science.

Among 451 diatom species, the most common were: Achnanthidium minutissimum (70% samples), Cocconeis placentula (61%), Gomphonema parvulum (40%), Navicula cryptocephala

(39%), Navicula gregaria (36%), Planothidium frequentissimum (36%), and Navicula lanceolata

(33%). A. minutissimum, C. placentula and G. parvulum are known to represent species complexes rather than individual biological species (e.g., Potapova & Hamilton 2007, Jahn

Abarca et al. 2013, Kermarrec et al. 2013) and this are not especially sensitive indicators of environmental conditions. On the other hand, high frequency and abundance of such species as

N. gregaria, N. lanceolata, and P. frequentissimum indicate considerable nutrient enrichment: these species are usually associated with high levels of nitrogen and phosphorus (Potapova &

Charles 2007). Remarkably, almost all 30 most abundant species are known as indicators of moderate to high eutrophication or general pollution, except a few species that are complexes of multiple cryptic species or are associated with acid mine drainage (Eunotia exigua and E. bilunaris). In streams with higher conductivity due to previous mining acitivites, diatoms characteristic for highly mineralized or brackish waters, such as Nitzschia dissipata, were dominant.

Exploratory multivariate analysis of diatom count data (Figure 9) revealed that the largest differences in community structure were caused by pH variation in studied water bodies. The

Eunotia species clustered in the left side of the diagram are indicative of low pH, and the arrow for this factor point in the opposite direction. The centroid for the water bodies affected by the acid mine drainage (AMD) although positioned to the left of the other centroids, was not at the extreme left side of the diagram. This happened because some AMD passive treatment ponds had rather high pH and their diatom communities were thus considerably different from those in

AMD water bodies with low pH. The ordination also elucidated which species were especially abundant in higher-conductivity waters and in various kinds of water bodies.

A few water bodies affected by the acid mine drainage had acidic water with conspicuous deposition of iron hydroxide or yellow boy (Figure 10) and diatom community dominated by a single species, Eunotia exigua. Interestingly, a series of passive treatment ponds at Jennings

Environmental Center demonstrated a successful restoration of water quality. Although the conductivity was high in all treatment ponds, pH was almost circumneutral in lower ponds and diatom community became much more diverse and abundant in comparison to the upper pond.

Some creeks with relatively low pH had rather diverse representatives of the genus Pinnularia, including several species that did not fit any published descriptions, but did not form large enough populations for a morphological detailed study (Figure 11).

Figure 9. Plot of the first and second axes resulting from the Detrended Correspondence Analysis of the diatom count data. Continuous (ph and conductivity) and nominal (type of the water body) environmental variables were used post-analysis and did not influence the ordination results. Only selected species with the highest weight are shown on the diagram.

Figure 10. The upper pond of the passive treatment system at Jennings Environmental Center, pH – 3.2, conductivity – 1357 S/cm.

Figure 11. Unknown and poorly known species of the genus Pinnularia found in Southwestern Pennsylvania in 2013. 1- Pinnularia sp. 1, 2- Pinnularia sp. 2, 3- Pinnularia sp. 3, 4- Pinnularia sp. 4, 5- Pinnularia sp. 5, 6- Pinnularia sp. 6, 7- Pinnularia sp. 7, 8, 17 – Pinnularia microstauron var. rostrata, 9 – P. subcommutata, 10- P. subcommutata var. nonfasciata, 11, 12 – P. schoefelderi, 13, 14 – P. brebissonii, 15 –P. cf. latarea, 16 – P. lundii, 18-21 –P. pseudogibba var. rostrata.

The invasive species Didymosphenia geminata was found in Youghiogheny River

(Ohiopyle SP). This species has been observed in the river since 2012. The growth was moderate, so that Didymosphenia did not form conspicuous masses and was found aming a diverse community of other diatoms and green algae (Figure 12). No growth of Didymosphenia was observed in any studied tributaries of the Youghiogheny River.

Figure 12. Right: underwater photograph of the epilithic algal community in Youghiogheny River (Ferncliff Penisula) showing moderate growth of diatoms and green algae. Didymosphenia geminata cells (left) were found in this community, although their abundance was low.

The conclusion of this work is a documentation of a rich diatom flora found in water bodies of Southwestern Pennsylvania. Although the diatom communities of this region are definitely far from pristine state, they are still highly diverse and provide vast opportunities for environmental monitoring and assessment. Further more detailed investigations of aquatic

17 ecosystems of this region would be beneficial for developing appropriate management guidelines and ultimately led to improved water quality.

Discussion and Management Recommendations

The diatom flora revealed in the course of this study is quite diverse, but is dominated by common pollution-tolerant species, typically found in moderately and even highly polluted rivers. The overall number of species (451) is lower than in previously studied diatom flora of

Northcentral Pennsylvania (622 species, Potapova 2010), although this number may be influenced by lower number of studied samples. In the Southwest 103 locations within the State

Parks were sampled, while in the North-central part of the State we sampled 140 sites on all kind of lands. A conspicuous difference between two floras is almost complete absence of pollution- sensitive species in the Southwest, which may be the legacy of intensive mining in this region in the past. The widespread acid mine drainage continues to affect aquatic communities even in the protected lands (Winter 2008). In North-central Pennsylvania a considerable number of streams had high-quality diatom communities dominated by native and rare species, while such habitats were practically absent in the Southwest.

Although the invasive species Didymosphenia geminata is by now firmly established in

Youghiogheny River, it was not observed to form excessive blooms. Its presence and possible spread nevertheless should be monitored since it will likely become more widespread (Spaulding &

Elwell 2007, Taylor & Bothwell 2014).

Diatoms in artificial lakes located in Southwestern Pennsylvania indicated moderate to high eutrophication. It would be beneficial to monitor lakes’ biological communities (Phyto- and ziooplankton and benthos) on a regular basis to prevent deterioration of water quality. An excessive bloom of cyanobacteria in Lake Arthur was a sure indication of nutrient enrichment directly leading to water-quality problems.

The samples collected in the course of this project and permanent diatom slides made from these samples are now stored in the ANSP Diatom Herbarium. These samples and slides are available for further studies involving various methodologies. For example, the diatoms might be counted in the future following bioassessment protocols, such as 500- or 600-valve counts. The data obtained from such observations might then be combined with data obtained from other surveys and used for a variety of purposes, such as inferring species optima and tolerances, or modeling species distributions. They can also be used as a reference in studies of human impacts and climate change. In fact, we are already starting to use these data as a benchmark for assessing impact of the fracking waste-water treatment facilities located on

Blacklick Creek, Western PA.

Table 1. Location and description of 153 diatom samples collected in State Parts of Southwestern Pennsylvania in 2013.

ANSP Date Site name Park Latitude Longitude Cond pH Microhabitat sample #

SWPA0001 4-May-13 Youghiogheny River, Ferncliff Ohiopyle State Park 39.87505 -79.49580 220 6.9 rocks Peninsula SWPA0002 4-May-13 Youghiogheny River, Ferncliff Ohiopyle State Park 39.87505 -79.49580 220 6.9 moss Peninsula SWPA0003 4-May-13 Wet wall Ohiopyle State Park 39.84227 -79.39468 178 7.5 moss

SWPA0004 4-May-13 Wet wall Ohiopyle State Park 39.84231 -79.46172 moss

SWPA0005 4-May-13 Long Run Ohiopyle State Park 39.84555 -79.46616 136 7.5 rocks

SWPA0006 4-May-13 Long Run Ohiopyle State Park 39.84555 -79.46616 136 7.5 sand

SWPA0007 4-May-13 Long Run Ohiopyle State Park 39.84555 -79.46616 136 7.5 moss

SWPA0008 4-May-13 Creek 1 Ohiopyle State Park 39.84620 -79.40400 71 7.6 gravel

SWPA0009 4-May-13 Creek 1 Ohiopyle State Park 39.84620 -79.40400 71 7.6 moss

SWPA0010 4-May-13 Wetland-creek Ohiopyle State Park 39.84951 -79.44738 40 7.3 moss

SWPA0011 5-May-13 Youghiogheny River, Ohiopyle State Park 39.90400 -79.47619 200 7.1 Lemanea Unauthorized rapids SWPA0012 5-May-13 Sugar Run Ohiopyle State Park 39.90599 -79.49122 48 7.3 rocks, poll under waterfall SWPA0013 5-May-13 Sugar Run Ohiopyle State Park 39.90599 -79.49122 48 7.3 moss in waterfall

SWPA0014 5-May-13 Jonathan Run Ohiopyle State Park 39.90293 -79.49040 64 7.1 rocks

SWPA0015 20-Jul-13 Kooser Spring Kooser State Park 40.06420 79.24316 515 6.2 silt

SWPA0016 20-Jul-13 Kooser Spring Kooser State Park 40.06485 79.24235 515 7.1 moss, silt

SWPA0017 20-Jul-13 Kooser Run Kooser State Park 40.06506 79.24246 462 7.1 rocks

SWPA0018 20-Jul-13 Kooser Run Kooser State Park 40.06506 79.24246 462 7.1 moss

SWPA0019 20-Jul-13 Kooser Run's mouth at Lake Kooser State Park 40.05817 79.22714 321 7.9 Elodea

SWPA0020 20-Jul-13 Unnamed tributary to Kooser Run Kooser State Park 40.05632 79.22307 116 6.1 Moss, sandy bottom

SWPA0021 20-Jul-13 Kooser Run below lake Kooser State Park 40.05632 79.22307 310 7.1 rocks

SWPA0022 20-Jul-13 Kooser Lake Kooser State Park 40.05700 79.22456 330 8.5 filamentous green algae

SWPA0023 20-Jul-13 Stahl Run Kooser State Park 40.05922 79.22717 80 7.1 rocks

SWPA0024 20-Jul-13 Laurel Hill Creek Laurel Hill State Park 40.00817 79.23267 217 7.1 rocks

SWPA0025 20-Jul-13 Bucks Run Laurel Hill State Park 40.01854 79.24088 20 5.3 rocks

SWPA0026 20-Jul-13 Bucks Run Laurel Hill State Park 40.01854 79.24088 20 5.3 moss

SWPA0027 20-Jul-13 Laurel Hill Lake Laurel Hill State Park 39.99749 79.23640 199 7.1 plankton

SWPA0028 20-Jul-13 Laurel Hill Lake Laurel Hill State Park 39.99749 79.23640 199 7.1 Nostoc

SWPA0029 20-Jul-13 Laurel Hill Lake Laurel Hill State Park 39.99749 79.23640 199 7.1 flocks near shore

SWPA0030 20-Jul-13 Laurel Hill Lake near shore Laurel Hill State Park 39.99473 79.23889 200 7.4 rocks

SWPA0031 20-Jul-13 Laurel Hill Lake near shore Laurel Hill State Park 39.99473 79.23889 200 7.4 plants

SWPA0032 20-Jul-13 Spruce Run Laurel Hill State Park 39.99224 79.24117 75 7.1 rocks

SWPA0033 21-Jul-13 Jones Mill Run Laurel Hill State Park 40.00369 79.24233 148 7.1 rocks

SWPA0034 21-Jul-13 Jones Mill Run Laurel Hill State Park 40.00369 79.24233 148 7.1 moss

SWPA0035 21-Jul-13 Creek 1 Laurel Ridge State 39.95039 79.35986 33 4.4 moss Park; south part SWPA0036 21-Jul-13 Creek 1 Laurel Ridge State 39.95039 79.35986 33 4.4 gravel and sand Park; south part SWPA0037 21-Jul-13 Creek 2 Laurel Ridge State 39.94822 79.35871 29 4.5 moss Park; south part

SWPA0038 21-Jul-13 Creek 2 Laurel Ridge State 39.94822 79.35871 29 4.5 gravel and sand Park; south part SWPA0039 21-Jul-13 Creek 3 Laurel Ridge State 39.94106 79.34830 31 4.8 moss Park; south part SWPA0040 21-Jul-13 Creek 3 Laurel Ridge State 39.94106 79.34830 31 4.8 sand Park; south part SWPA0041 21-Jul-13 Creek 4 Laurel Ridge State 39.93114 79.34616 24 4.9 moss Park; south part SWPA0042 21-Jul-13 Creek 4 Laurel Ridge State 39.93114 79.34616 24 4.9 gravel and sand Park; south part SWPA0043 21-Jul-13 Creek 5 Laurel Ridge State 39.84448 79.48280 165 4.5 moss Park; south part SWPA0044 21-Jul-13 Creek 5 Laurel Ridge State 39.84448 79.48280 165 4.5 gravel and sand Park; south part SWPA0045 21-Jul-13 Meadow Run Ohiopyle State Park 39.84897 79.49068 121 7.0 rocks

SWPA0046 21-Jul-13 Youghiogheny River Ohiopyle State Park 39.86920 79.49621 191 7.1 rocks

SWPA0047 21-Jul-13 Youghiogheny River Ohiopyle State Park 39.86920 79.49621 191 7.1 moss in the puddle near the river SWPA0048 21-Jul-13 Youghiogheny River Ohiopyle State Park 39.86920 79.49621 191 7.1 blue green algae on the rocks SWPA0049 21-Jul-13 Youghiogheny River at Ohiopyle State Park 39.80688 79.36442 115 6.8 filamentous green algae Confluence SWPA0050 21-Jul-13 Youghiogheny River at Ohiopyle State Park 39.80688 79.36442 115 6.8 rocks Confluence SWPA0051 21-Jul-13 Spring 1 Laurel Ridge State 39.95103 79.36066 33 5.3 moss Park; south part SWPA0052 22-Jul-13 Linn Run Linn Run State Park 40.15406 79.21099 27 6.3 rocks

SWPA0053 22-Jul-13 Creek 6 Linn Run State Park 40.15356 79.22034 54 6.6 rocks

SWPA0054 22-Jul-13 Creek 6 Linn Run State Park 40.15356 79.22034 54 6.6 moss

SWPA0055 22-Jul-13 Grove Run Linn Run State Park 40.15273 79.22590 46 7.1 moss

SWPA0056 22-Jul-13 Grove Run Linn Run State Park 40.15273 79.22590 46 7.1 rocks

SWPA0057 22-Jul-13 Rocks Run Linn Run State Park 40.15775 79.23402 35 7.2 moss

SWPA0058 22-Jul-13 Rocks Run Linn Run State Park 40.15775 79.23402 35 7.2 rocks

SWPA0059 22-Jul-13 Small Creek 7 Linn Run State Park 40.15738 79.23312 39 5.2 rocks

SWPA0060 22-Jul-13 Linn Run at Flat Rock trail Linn Run State Park 40.17394 79.23552 47 6.4 moss

SWPA0061 22-Jul-13 Adam's Run above Adam's Fall Linn Run State Park 40.16755 79.23132 43 4.9 moss

SWPA0062 22-Jul-13 Adam's Run above Adam's Fall Linn Run State Park 40.16755 79.23132 43 4.9 rocks

SWPA0063 22-Jul-13 Creek 8 Laurel Ridge State 40.17278 79.12000 192 6.7 rocks Park SWPA0064 22-Jul-13 Creek 9 Laurel Ridge State 40.16763 79.12550 97 7.1 moss Park SWPA0065 22-Jul-13 Creek 9 Laurel Ridge State 40.16763 79.12550 97 7.1 rocks Park SWPA0066 22-Jul-13 Creek 10 Laurel Ridge State 40.19497 79.10711 30 5.8 moss Park SWPA0067 22-Jul-13 Creek 10 Laurel Ridge State 40.19497 79.10711 30 5.8 gravel and sand Park SWPA0068 22-Jul-13 Creek 11 Laurel Ridge State 40.18270 79.12205 132 7.1 sand Park SWPA0069 23-Jul-13 Clarks Run Charles F. Lewia 40.41185 78.98380 63 7.2 rocks Natural Area SWPA0070 23-Jul-13 Clarks Run Charles F. Lewia 40.41185 78.98380 63 7.2 moss Natural Area SWPA0071 23-Jul-13 Laurel Run Yellow Creek State 40.57895 78.99983 247 7.7 moss Park SWPA0072 23-Jul-13 Laurel Run Yellow Creek State 40.57895 78.99983 247 7.7 rocks Park SWPA0073 23-Jul-13 Dragonfly Pond Yellow Creek State 40.57375 79.00887 46 7.0 aquatic plants Park SWPA0074 23-Jul-13 Dragonfly Pond Yellow Creek State 40.57375 79.00887 46 7.0 silt Park SWPA0075 23-Jul-13 Yellow Creek Lake Yellow Creek State 40.57348 79.01358 215 8.4 plankton Park SWPA0076 23-Jul-13 Yellow Creek Lake Yellow Creek State 40.57348 79.01358 215 8.4 Potamogeton Park SWPA0077 23-Jul-13 Yellow Creek Lake (bay Area, Yellow Creek State 40.57192 79.01741 200 6.9 Lotus stems covered by Lotus) Park

SWPA0078 23-Jul-13 Yellow Creek Lake (bay Area, Yellow Creek State 40.57192 79.01741 200 6.9 Miryophillum? covered by Lotus) Park SWPA0079 23-Jul-13 Creek 12 Yellow Creek State 79.02000 101 7.1 rocks Park SWPA0080 23-Jul-13 Little Yellow Creek Yellow Creek State 40.56514 79.01726 203 7.1 rocks Park SWPA0081 Little Yellow Creek Yellow Creek State 40.56514 79.01726 203 7.1 moss Park SWPA0082 23-Jul-13 Creek 13 Yellow Creek State 40.56659 79.04146 105 7.2 rocks Park SWPA0083 23-Jul-13 Grammas Cove Yellow Creek State 40.56887 79.03886 198 6.9 filamentous green algae Park SWPA0084 23-Jul-13 Grammas Cove Yellow Creek State 40.56887 79.03886 198 6.9 Lotus stems and leaves Park SWPA0085 23-Jul-13 Wetland Yellow Creek State 40.56854 79.03988 107 7.2 aquatic plants (maybe Park Phragmites) SWPA0086 23-Jul-13 Fishing pier (boy scout camp Yellow Creek State 40.57965 79.03607 190 8.8 Miryophillum area) Park SWPA0087 23-Jul-13 Fishing pier (boy scout camp Yellow Creek State 40.57965 79.03607 190 8.8 rocks area) Park SWPA0088 23-Jul-13 Wetland Keystone State Park 40.37419 79.37638 175 7.9 aquatic plants

SWPA0089 23-Jul-13 Davis Run Keystone State Park 40.37717 79.37504 197 7.4 rocks

SWPA0090 23-Jul-13 Keystone Lake Keystone State Park 40.37389 79.37902 167 9.4 Miryophillum

SWPA0091 23-Jul-13 Keystone Lake Keystone State Park 40.37389 79.37902 167 9.4 silt

SWPA0092 23-Jul-13 McCune Run Keystone State Park 40.37520 79.39386 198 7.7 rocks

SWPA0093 23-Jul-13 AMD Keystone State Park 40.37513 79.39781 117 3.3 orange floc

SWPA0094 23-Jul-13 Keystone Lake near the dam Keystone State Park 40.37387 79.39042 191 9.4 filamentous green algae

SWPA0095 23-Jul-13 Keystone Lake near the dam Keystone State Park 40.37387 79.39042 191 9.4 rocks

SWPA0096 23-Jul-13 McCune Run above the lake Keystone State Park 40.37383 79.36367 200 7.6 silt

SWPA0097 24-Jul-13 Big Spring Run Laurel Ridge State 40.40631 78.99902 34 7.0 moss Park

SWPA0098 24-Jul-13 Big Spring Run Laurel Ridge State 40.40631 78.99902 34 7.0 rocks Park SWPA0099 24-Jul-13 Big Spring Reservoir Laurel Ridge State 40.40798 79.00053 32 7.1 aquatic plants Park SWPA0100 24-Jul-13 Big Spring Reservoir Laurel Ridge State 40.40798 79.00053 32 7.1 rocks Park SWPA0101 19-Sep-13 Big Run Jennings 41.00847 80.00623 561 7.8 rocks Environmental Center SWPA0102 19-Sep-13 Big Run Jennings 41.00847 80.00623 561 7.8 sand and silt Environmental Center SWPA0103 19-Sep-13 Passive treatment pond (lower) Jennings 41.00800 80.00036 1260 7.9 moss and filamnetous Environmental Center greens SWPA0104 19-Sep-13 Passive treatment pond (upper), Jennings 41.00883 79.99960 1357 3.2 reddish-orange flakes rusty Environmental Center SWPA0105 19-Sep-13 Lower pond of the lower system Jennings 41.00718 80.00179 1060 6.9 muck, moss and grass Environmental Center SWPA0106 19-Sep-13 Muddy Creek Moraine State Park 40.97213 79.97417 220 6.7 greens

SWPA0107 19-Sep-13 Swamp Run Moraine State Park 40.94968 79.99326 430 7.1 moss

SWPA0108 20-Sep-13 Lake Arthur, shallow "wetland", Moraine State Park 40.93722 80.03133 220 7.3 aqautic plants (Elodea) overgrown near-shore SWPA0109 20-Sep-13 Lake Arthur, launch area near Moraine State Park 40.95207 80.04059 188 9.0 plants bridge SWPA0110 20-Sep-13 Lake Arthur, launch area near Moraine State Park 40.95207 80.04059 188 9.0 plankton (bloom of bridge Gomphospheria) SWPA0111 20-Sep-13 Lake Arthur, launch area near Moraine State Park 40.95207 80.04059 188 9.0 rocks bridge SWPA0112 20-Sep-13 creek #1, tributary of lake Arthur Moraine State Park 40.97558 80.02994 258 7.4 rocks, silt, bluegreens

SWPA0113 20-Sep-13 creek #2, tributary of lake Arthur Moraine State Park 40.97665 80.00406 330 7.4 silt

SWPA0114 20-Sep-13 Small pond Moraine State Park 40.96590 80.07925 120 9.4 plants (Elodea)

SWPA0115 20-Sep-13 creek #3, tributary of lake Arthur Moraine State Park 40.96179 80.06731 540 8.4 silt

SWPA0116 20-Sep-13 creek #4, tributary of lake Arthur Moraine State Park 40.96275 80.09255 270 7.4 silt

SWPA0117 20-Sep-13 Lake Arthur, Watts Bay Marina Moraine State Park 40.96113 80.09986 199 8.9 plants (Elodea)

SWPA0118 20-Sep-13 creek #5, tributary of lake Arthur Moraine State Park 40.97415 80.10175 1730 7.3 yellow flakes, silt

SWPA0119 20-Sep-13 creek #6, tributary of lake Arthur Moraine State Park 40.97588 80.12577 575 7.1 yellow silt

SWPA0120 20-Sep-13 Muddy Creek, below Lake Arthur Moraine State Park 40.96288 80.13099 296 7.4 Potamogeton

SWPA0121 20-Sep-13 Muddy Creek, below Lake Arthur Moraine State Park 40.96288 80.13099 296 7.4 rocks

SWPA0122 20-Sep-13 Slippery Rock Creek McConnell Mill State 40.95423 80.17004 524 8.3 silt, rocks Park SWPA0123 20-Sep-13 small creek, tributary to Slippery McConnell Mill State 40.95423 80.17004 940 8.2 moss Rock Creek, seeping over rocks Park and moss SWPA0124 20-Sep-13 Hell Run McConnell Mill State 40.93122 80.23960 715 7.6 rocks Park SWPA0125 20-Sep-13 Slippery Rock Creek @ McConnell Mill State 40.90398 80.22442 530 8.3 rocks Armstrong Bridge Park SWPA0126 20-Sep-13 tributary to Slippery Rock McConnell Mill State 40.93710 80.17809 650 8.1 rocks Park SWPA0127 20-Sep-13 tributary to Slippery Rock McConnell Mill State 40.93710 80.17809 650 8.1 moss Park SWPA0128 20-Sep-13 Lake Arthur Moraine State Park 40.92385 80.06944 206 9.6 rocks

SWPA0129 20-Sep-13 Lake Arthur Moraine State Park 40.92385 80.06944 206 9.6 plants

SWPA0130 21-Sep-13 Creek #1 Hillman State Park 40.45531 80.38107 1980 7.9 rocks

SWPA0131 21-Sep-13 Creek #2 Hillman State Park 40.45716 80.40280 2530 7.8 rocks

SWPA0132 22-Sep-13 Racoon Creek Raccoon Creek State 40.50766 80.35987 1575 8.0 rocks Park SWPA0133 22-Sep-13 Traverse Creek Raccoon Creek State 40.50660 80.38095 229 7.9 rocks Park SWPA0134 22-Sep-13 Raccoon Lake Raccoon Creek State 40.50506 80.38766 230 7.7 rocks Park SWPA0135 22-Sep-13 Raccoon Lake Raccoon Creek State 40.50506 80.38766 230 7.7 plants Park SWPA0136 22-Sep-13 Heritage Creek Raccoon Creek State 40.50081 80.38947 278 7.4 rocks Park

SWPA0137 22-Sep-13 Traverse Creek between lakes Raccoon Creek State 40.50122 80.42101 300 7.6 rocks Park SWPA0138 22-Sep-13 Frankfort Mineral Springs Raccoon Creek State 40.49848 80.43134 354 8.0 rocks Park SWPA0139 22-Sep-13 Frankfort Mineral Springs @ rock Raccoon Creek State 40.49848 80.43134 354 8.0 mosses (waterfall, aerial) overhang Park SWPA0140 22-Sep-13 Frankfort Mineral Springs @ rock Raccoon Creek State 40.49848 80.43134 438 7.0 jelly from rock wall overhang , #2 Park SWPA0141 22-Sep-13 Frankfort Mineral Springs @ rock Raccoon Creek State 40.49848 80.43134 438 7.0 rusty film from rock wall overhang , #2 Park SWPA0142 22-Sep-13 Frankfort Mineral Spring, #3 Raccoon Creek State 40.49759 80.42825 573 8.0 rocks Park SWPA0143 22-Sep-13 Upper Lake Raccoon Creek State 40.51170 80.44301 328 7.9 Cladophora Park SWPA0144 22-Sep-13 Camp Creek Raccoon Creek State 40.51238 80.44523 223 8.0 Cladophora Park SWPA0145 22-Sep-13 Service Run Raccoon Creek State 40.50878 80.42459 307 8.1 rocks Park SWPA0146 22-Sep-13 Service Run Raccoon Creek State 40.50878 80.42459 307 8.1 Cladophora Park SWPA0147 22-Sep-13 Panther Lick Hollow Ryerson State Park 39.88358 80.44955 560 8.0 rocks

SWPA0148 22-Sep-13 Panther Lick Hollow Ryerson State Park 39.88358 80.44955 560 8.0 filamentous greens

SWPA0149 22-Sep-13 Polly Hollow Ryerson State Park 39.88567 80.44498 595 8.4 rocks

SWPA0150 22-Sep-13 Kent Run Ryerson State Park 39.83352 80.43555 330 7.7 rocks

SWPA0151 22-Sep-13 Kent Run Ryerson State Park 39.83352 80.43555 330 7.7 moss

SWPA0152 22-Sep-13 Munnell Hollow Ryerson State Park 39.83334 80.44155 310 8.3 rocks

SWPA0153 22-Sep-13 North Fork of Drunkard Fork Ryerson State Park 39.88255 80.43658 246 7.7 rocks

Table 2. List of 451 diatom taxa found in 153 samples collected in Southwestern Pennsylvania in 2013.

Number of Taxon occurrences Achnanthes coarctata (Brébisson) Grunow 1 Achnanthes subhudsonis var. kraeuselii (Cholnoky) Cholnoky 1 Achnanthidium affine (Grunow) Czarnecki 1 Achnanthidium altergracillima (Lange-Bertalot) Round et Bukhtiyarova 16 Achnanthidium atomus (Hustedt) Monnier, Lange-Bertalot et Ector 2 Achnanthidium catenatum (Bily et Marvan) Lange-Bertalot 7 Achnanthidium deflexum (Reimer) Kingston 6 Achnanthidium druartii Rimet & Couté 3 Achnanthidium eutrophilum (Lange-Bertalot) Lange-Bertalot 16 Achnanthidium exiguum (Grunow) Czarnecki 8 Achnanthidium latecephalum Kobayasi 14 Achnanthidium minutissimum (Kützing) Czarnecki 107 Achnanthidium pyrenaicum (Hustedt) Kobayasi 20 Achnanthidium reimeri (Camburn) Ponader et Potapova 31 Achnanthidium rivulare Potapova et Ponader 41 Adlafia bryophila (Petersen) Lange-Bertalot 2 Amphipleura pellucida (Kützing) Kützing 12 Amphora copulata (Kützing) Schoeman et Archibald 8 Amphora inariensis Krammer 6 Amphora ovalis (Kützing) Kützing 4 Amphora pediculus (Kützing) Grunow 39 Amphora pseudomontana (Cholnoky) Levkov 1 Asterionella formosa Hassal 3 Asterionella ralfsii Smith 2 Aulacoseira ambigua (Grunow) Simonsen 16 Aulacoseira granulata (Ehrenberg) Simonsen 6 Aulacoseira italica (Ehrenberg) Simonsen 1 Aulacoseira pusilla (Meister) Tuji & Houk 8 Bacillaria paradoxa Gmelin 15 Brachysira brebissonii Ross 5 Brachysira microcephala (Grunow) Compère 24 Caloneis bacillum (Grunow) Cleve 21 Caloneis silicula (Ehrenberg) Cleve 1 Caloneis tenuis (Gregory) Krammer 8 Campylodiscus hibernicus Ehrenberg 1 Cavinula lapidosa (Krasske) Lange-Bertalot 1 Cavinula mollicula (Hustedt) Lange-Bertalot 1 Chamaepinnularia begeri (Krasske) Lange-Bertalot 2 Cocconeis pediculus Ehrenberg 16 Cocconeis placentula Ehrenberg 78 Craticula ambigua (Ehrenberg) Mann 2 Craticula riparia (Hustedt) Lange-Bertalot 1 Craticula sp. 1 1

Ctenophora pulchella (Ralfs ex Kützing) Williams et Round 28 Cyclostephanos cf. invisitatus (Hohn et Hellerman) Theriot, Stoermer et Håkansson 1 Cyclotella atomus Hustedt 1 Cyclotella bodanica Grunow 13 Cyclotella distinguenda Hustedt 10 Cyclotella meneghiniana Kützing 27 Cyclotella ocellata Pantocsek 1 Cymatopleura elliptica (Brébisson) Smith 1 Cymatopleura solea (Brébisson) Smith 6 Cymbella affinis Kützing 3 Cymbella amphicephala var. hercynica (Schmidt) Cleve 1 Cymbella aspera (Ehrenberg) Peragallo 6 Cymbella cistula (Ehrenberg) Kirchner 15 Cymbella cymbiformis Agardh 1 Cymbella excisiformis Krammer 2 Cymbella gracilis (Ehrenberg) Kützing 6 Cymbella hustedtii Krasske 16 Cymbella neoleptoceros Krammer 6 Cymbella proxima Reimer 3 Cymbella sp. 1 1 Cymbella sp. 2 1 Cymbella sp. 3 1 Cymbella sp. 4 2 Cymbella subturgidula Krammer 2 Cymbella tropica Krammer 13 Cymbella tumida (Brébisson ex Kützing) Van Heurck 19 Cymbella tumidula Grunow ex Schmidt 2 Cymbella turgidula Grunow 7 Cymbopleura naviculiformis (Auerswald) Krammer 22 Cymbopleura subcuspidata (Krammer) Krammer 2 Decussata placenta (Ehrenberg) Lange-Bertalot et Metzeltin 1 Delicata delicatula (Kützing) Krammer 6 Denticula subtilis Grunow 1 Diadesmis biceps Arnott 7 Diadesmis gallica Smith 3 Diadesmis perpusilla (Grunow) Mann 4 Diatoma mesodon (Ehrenberg) Kützing 16 Diatoma moniliformis Kützing 22 Diatoma vulgaris Bory 16 Diatomella balfouriana (Smith) Greville 1 Didymosphenia geminata (Lyngbye) Schmidt 2 Diploneis elliptica (Kützing) Cleve 4 Diploneis marginestriata Hustedt 1 Diploneis oblongella (Naegeli ex Kützing) Ross 3 Diploneis ovalis (Hilse ex Rabenhorst) Cleve 2 Discostella stelligera (Hustedt) Houk et Klee 29 Discostella woltereckii (Hustedt) Houk et Klee 2 Encyonema appalachianum Potapova sp. nov. 20

Encyonema auerswaldii Rabenhorst 6 Encyonema hamsherae Winter & Bahls 21 Encyonema minutum (Hilse) Mann 42 Encyonema prostratum (Berkeley) Kützing 6 Encyonema reichardtii (Krammer) Mann 4 Encyonema silesiacum (Bleisch) Mann 24 Encyonema sp. 1 1 Encyonema sp. 2 8 Encyonema sp. 3 1 Encyonema sp. 4 1 Encyonema triangulum (Ehrenberg) Kützing 2 Encyonopsis cesatii (Rabenhorst) Krammer 2 Encyonopsis microcephala (Grunow) Krammer 27 Eolimna minima (Grunow) Lange-Bertalot 39 Epithemia adnata (Kützing) Brébisson 2 Epithemia sorex Kützing 1 Eucocconeis flexella (Kützing) Cleve 1 Eucocconeis laevis (Østrup) Lange-Bertalot 13 Eunotia bilunaris (Ehrenberg) Mills 31 Eunotia circumborealis Lange-Bertalot et Nörpel 2 Eunotia cristagalli Cleve 1 Eunotia dianae-stitinensis Lange-Bertalot & Witkowski 1 Eunotia exigua (Brébisson ex Kützing) Rabenhorst 43 Eunotia formica Ehrenberg 3 Eunotia implicata Nörpel, Lange-Bertalot et Alles 19 Eunotia incisa Smith ex Gregory 18 Eunotia minor (Kützing) Grunow 4 Eunotia muscicola Krasske 12 Eunotia naegelii Migula 4 Eunotia rhomboidea Hustedt 20 Eunotia romanowii Siver 1 Eunotia sp. 1 1 Eunotia subarcuatoides Alles, Nörpel et Lange-Bertalot 4 Fallacia lenzii (Hustedt) Lange-Bertalot 4 Fallacia omissa (Hustedt) Mann 3 Fallacia sp. 1 1 Fallacia sp. 2 1 Fallacia subhamulata (Grunow) Mann 1 Fallacia tenera (Hustedt) Mann 3 Fragilaria bidens Heiberg 5 Fragilaria capucina cf. var. gracilis NAWQA WRC (Østrup) Hustedt 1 Fragilaria capucina Desmazières 1 Fragilaria capucina var. amphicephala (Kützing) Lange-Bertalot ex Bukhtiyarova 1 Fragilaria capucina var. gracilis (Østrup) Hustedt 14 Fragilaria capucina var. mesolepta Rabenhorst 6 Fragilaria capucina var. rumpens (Kützing) Lange-Bertalot 5 Fragilaria crotonensis Kitton 16 Fragilaria nanana Lange-Bertalot 3

Fragilaria tenera (Smith) Lange-Bertalot 9 Fragilaria vaucheriae (Kützing) Petersen 34 Fragilariforma virescens (Ralfs) Williams et Round 8 Frustulia amphipleuroides (Grunow) Cleve-Euler 12 Frustulia crassinervia (Brébisson) Lange-Bertalot et Krammer 12 Frustulia neomundana Lange-Bertalot & metzeltin 1 Frustulia rhomboides (Ehrenberg) deToni 1 Frustulia saxonica Rabenhorst 13 Frustulia vulgaris (Thwaites) De Toni 29 Frustulia weinholdii Hustedt 4 Geissleria acceptata (Hustedt) Lange-Bertalot et Metzeltin 7 Geissleria decussis (Hustedt) Lange-Bertalot et Metzeltin 12 Geissleria ignota (Krasske) Lange-Bertalot et Metzeltin 2 Geissleria kriegeri (Krasske) Lange-Bertalot 2 Geissleria similis (Krasske) Lange-Bertalot & Metzeltin 1 Gomphonema acuminatum Ehrenberg 9 Gomphonema affine Kützing 2 Gomphonema amoenum Lange-Bertalot 1 Gomphonema angustatum (Kützing) Rabenhorst 44 Gomphonema apicatum Ehrenberg 3 Gomphonema capitatum Ehrenberg 12 Gomphonema cf. pygmaeum Kociolek et Stoermer 2 Gomphonema clavatum Ehrenberg 2 Gomphonema drutelingense Reichardt 6 Gomphonema exilissimum (Grunow) Lange-Bertalot 2 Gomphonema freesei Lowe et Kociolek 9 Gomphonema gracile Ehrenberg emend. Van Heurck 14 Gomphonema intricatum var. vibrio (Ehrenberg) Cleve 1 Gomphonema italicum Kützing 1 Gomphonema kobayasii Kociolek et Kingston 8 Gomphonema manubrium Fricke 1 Gomphonema micropus Kützing 1 Gomphonema minusculum Krasske 1 Gomphonema minutum (Agardh) Agardh 13 Gomphonema montanum Schumann 5 Gomphonema olivaceoides Hustedt 15 Gomphonema olivaceum (Lyngbye) Kützing 8 Gomphonema pala Reichardt 3 Gomphonema parvulius (Lange-Bertalot et Reichardt) Lange-Bertalot et Reichardt 3 Gomphonema parvulum (Kützing) Kützing 61 Gomphonema productum (Grunow) Lange-Bertalot et Reichard 3 Gomphonema pumilum (Grunow) Reichardt et Lange-Bertalot 1 Gomphonema pygmaeum Kociolek et Stoermer 2 Gomphonema sp. 1 1 Gomphonema sp. 2 1 Gomphonema sp. 3 1 Gomphonema sp. 4 1 Gomphonema sphaerophorum Ehrenberg 6

Gomphonema subclavatum (Grunow) Grunow 2 Gyrosigma acuminatum (Kützing) Rabenhorst 8 Gyrosigma attenuatum (Kützing) Rabenhorst 4 Gyrosigma obtusatum (Sullivant et Wormley) Boyer 7 Gyrosigma scalproides (Rabenhorst) Cleve 1 Gyrosigma sciotoense (Sullivan et Wormley) Cleve 1 Halamphora montana (Krasske) Levkov 13 Halamphora normannii (Rabenhorst) Levkov 3 Halamphora veneta (Kützing) Levkov 4 Hantzschia amphioxys (Ehrenberg) Grunow 5 Hippodonta capitata (Ehrenberg) Lange-Bertalot, Metzeltin et Witkowski 8 Karayevia clevei (Grunow) Bukhtiyarova 23 Karayevia laterostrata (Hantzsch) Bukhtiyarova 4 Lemnicola hungarica (Grunow) Round et Basson 1 Luticola mutica (Kützing) Mann 7 Mayamaea agrestis (Hustedt) Lange-Bertalot 1 Mayamaea cahabaensis Morales & Manoylov 1 Melosira varians Agardh 35 Meridion circulare (Greville) Agardh 49 Meridion circulare var. constrictum (Ralfs) Van Heurck 3 Microcostatus krasskei (Hustedt) Johansen et Sray 3 Navicula angusta Grunow 6 Navicula antonii Lange-Bertalot 16 Navicula canalis Patrick 12 Navicula capitatoradiata Germain 21 Navicula caterva Hohn et Hellerman 7 Navicula cf. notha REIMER Wallace 1 Navicula cincta (Ehrenberg) Ralfs 3 Navicula cryptocephala Kützing 59 Navicula cryptotenella Lange-Bertalot in Krammer et Lange-Bertalot 30 Navicula difficillima Hustedt 5 Navicula erifuga Lange-Bertalot 9 Navicula germainii Wallace 37 Navicula gregaria Donkin 56 Navicula hintzii Lange-Bertalot 2 Navicula integra (Smith) Ralfs 1 Navicula kotschyi Grunow 4 Navicula lanceolata (Agardh) Ehrenberg 50 Navicula leistikowii Lange-Bertalot 1 Navicula leptostriata Jørgensen 2 Navicula libonensis Schoeman 5 Navicula longicephala cf. var. vilaplanii UMICH Lange-Bertalot et Sabater 2 Navicula longicephala Hustedt 2 Navicula lundii Reichardt 6 Navicula microcari Lange-Bertalot 1 Navicula modica Hustedt 1 Navicula notha Wallace 10 Navicula oligotraphenta Lange-Bertalot et Hofmann 2

Navicula protracta (Grunow) Cleve 1 Navicula protractoides (Hustedt) Witkowski et Lange-Bertalot 2 Navicula pseudoventralis Hustedt 2 Navicula radiosa Kützing 19 Navicula reichardtiana Lange-Bertalot 2 Navicula rhynchocephala Kützing 21 Navicula rostellata Kützing 14 Navicula schadei Krasske 1 Navicula schmassmannii Hustedt 1 Navicula schroeteri var. escambia Patrick 26 Navicula sp. 1 5 Navicula sp. 10 1 Navicula sp. 2 6 Navicula sp. 3 2 Navicula sp. 4 5 Navicula sp. 5 2 Navicula sp. 6 1 Navicula sp. 7 1 Navicula sp. 8 1 Navicula sp. 9 2 Navicula tenelloides Hustedt 2 Navicula tridentula Krasske 3 Navicula tripunctata (Müller) Bory 28 Navicula trivialis Lange-Bertalot 9 Navicula veneta Kützing 15 Navicula vilaplanii (Lange-Bertalot et Sabater) Lange-Bertalot et Sabater 3 Navicula viridulacalcis (Hustedt) Lange-Bertalot 6 Neidiopsis sp. 1 1 Neidium alpinum Hustedt 3 Neidium ampliatum (Ehrenberg) Krammer 7 Neidium binodis (Ehrenberg) Hustedt 1 Neidium bisulcatum (Lagerstedt) Cleve 1 Neidium hercynicum Mayer 2 Nitzschia acicularioides Hustedt 2 Nitzschia acicularis (Kützing) Smith 2 Nitzschia amphibia fo. Frauenfeldii (Grunow) Lange-Bertalot 1 Nitzschia amphibia Grunow 25 Nitzschia amphibioides Hustedt 2 Nitzschia archibaldii Lange-Bertalot 10 Nitzschia bacillum Hustedt 1 Nitzschia biacrula Hohn et Hellerman 2 Nitzschia calida Grunow in Cleve et Grunow 1 Nitzschia capitellata Hustedt 10 Nitzschia clausii Hantzsch 7 Nitzschia dissipata (Kützing) Grunow 42 Nitzschia dissipata var. media (Hantzsch) Grunow 3 Nitzschia draveillensis Coste et Ricard 3 Nitzschia dubia Smith 2

Nitzschia filiformis (Smith) Van Heurck 2 Nitzschia filiformis var. conferta (Reichardt) Lange-Bertalot 1 Nitzschia fonticola Grunow 4 Nitzschia frustulum (Kützing) Grunow 31 Nitzschia gessneri Hustedt 1 Nitzschia gracilis Hantzsch ex Rabenhorst 5 Nitzschia hantzschiana Rabenhorst 1 Nitzschia heufleriana Grunow 2 Nitzschia homburgienis Lange-Bertalot 3 Nitzschia incognita Legler et Krasske 2 Nitzschia inconspicua Grunow 10 Nitzschia intermedia Hantzsch ex Cleve et Grunow 4 Nitzschia liebethruthii Rabenhorst 14 Nitzschia linearis (Agardh) Smith 38 Nitzschia microcephala Grunow 2 Nitzschia nana Grunow ex Van Heurck 6 Nitzschia palea (Kützing) Smith 36 Nitzschia palea var. debilis (Kützing) Grunow 37 Nitzschia paleacea Grunow ex Van Heurck 4 Nitzschia perminuta (Grunow) Peragallo 1 Nitzschia pumila Hustedt 3 Nitzschia pura Hustedt 1 Nitzschia pusilla Grunow 3 Nitzschia recta Hantzsch ex Rabenhorst 6 Nitzschia sigma (Kützing) Smith 1 Nitzschia sigmoidea (Nitzsch) Ehrenberg 3 Nitzschia sinuata var. delognei (Grunow) Lange-Bertalot 1 Nitzschia sinuata var. tabellaria (Grunow) Grunow 11 Nitzschia sociabilis Hustedt 11 Nitzschia sp. 1 2 Nitzschia sp. 2 1 Nitzschia sp. 3 1 Nitzschia sp. 4 1 Nitzschia subacicularis Hustedt 1 Nitzschia tubicola Grunow in Cleve et Grunow 1 Nupela elegantula Potapova 1 Nupela frezelii Potapova 3 Nupela lapidosa (Krasske) Lange-Bertalot 17 Nupela wellneri (Lange-Bertalot) Lange-Bertalot 1 Pinnularia acidophila Hofmann et Krammer 2 Pinnularia acrosphaeria (Brébisson) Smith 1 Pinnularia borealis Ehrenberg 1 Pinnularia brebissonii (Kützing) Rabenhorst 3 Pinnularia burkii Patrick 2 Pinnularia cf. divergens var. media Krammer 1 Pinnularia cf. latarea Krammer 1 Pinnularia cf. pulchella var. canadensis Krammer 1 Pinnularia divergens var. sublinearis Cleve 1

Pinnularia gibba Ehrenberg 1 Pinnularia lundii Hustedt 2 Pinnularia microstauron var. rostrata Krammer 5 Pinnularia obscura Krasske 5 Pinnularia pisciculus Ehrenberg 1 Pinnularia polyonca (Brébisson) Smith 1 Pinnularia pseudogibba var. rostrata Krammer 4 Pinnularia schoefelderi Krammer 2 Pinnularia sinistra Krammer 2 Pinnularia sp. 1 1 Pinnularia sp. 2 1 Pinnularia sp. 3 1 Pinnularia sp. 4 1 Pinnularia sp. 5 3 Pinnularia sp. 6 1 Pinnularia sp. 7 1 Pinnularia spp. 1 Pinnularia stomatophora (Grunow) Cleve 1 Pinnularia subcapitata Gregory 1 Pinnularia subcapitata var. elongata Krammer 1 Pinnularia subcommutata Krammer 1 Pinnularia subcommutata var. nonfasciata Krammer 1 Pinnularia subgibba Krammer 1 Pinnularia sudetica (Hilse) Peragallo 2 Pinnularia viridiformis Krammer 1 Pinnularia viridiformis var. minor Krammer 1 Placoneis clementis (Grunow) Cox 1 Placoneis elginensis (Gregory) Cox 4 Planothidium daui (Foged) Lange-Bertalot 1 Planothidium frequentissimum (Lange-Bertalot) Lange-Bertalot 55 Planothidium lanceolatum (Brébisson ex Kützing) Lange-Bertalot 34 Planothidium minutissimum (Krasske) Lange-Bertalot 1 Planothidium oestrupii (Cleve-Euler) Round et Bukhtiyarova 1 Planothidium peragalli Brun et Héribaud 1 Planothidium rostratum (Østrup) Lange-Bertalot 15 Planothidium sp. 1 1 Planothidium stewartii (Patrick) Lange-Bertalot 1 Platessa bahlsii Potapova 9 Pleurosira laevis (Ehrenberg) Compère 1 Psammothidium altaicum Bukhtiyarova 1 Psammothidium bioretii (Germain) Bukhtiyarova et Round 5 Psammothidium chlidanos (Hohn et Hellerman) Lange-Bertalot 6 Psammothidium grischunum fo. daonensis (Lange-Bertalot ex Lange-Bertalot et Krammer) Bukhtiyarova et Round 8 Psammothidium helveticum (Hustedt) Bukhtiyarova et Round 5 Psammothidium marginulatum (Grunow) Bukhtiyarova et Round 16 Psammothidium scoticum (Flower et Jones) Bukhtiyarova et Round 3 Psammothidium subatomoides (Hustedt) Bukhtiyarova et Round 1

Psammothidium ventralis (Krasske) Bukhtiyarova et Round 1 Pseudostaurosira brevistriata (Grunow) Williams et Round 5 Reimeria sinuata (Gregory) Kociolek et Stoermer 34 Reimeria uniseriata Sala, Guerrero et Ferrario 4 Rhoicosphenia abbreviata (Agardh) Lange-Bertalot 28 Rhopalodia constricta (Smith) Krammer 1 Rhopalodia gibba (Ehrenberg) Müller 6 Rhopalodia operculata (Agardh) Håkansson 2 Rossithidium anastasiae (Kaczmarska) Potapova 3 Sellaphora disjuncta (Hustedt) Mann 1 Sellaphora joubaudii (Germain) Aboal 1 Sellaphora laevissima (Kützing) Mann 2 Sellaphora pupula (Kützing) Meresckowsky 10 Sellaphora pupula var. capitata Skvortzow et Meyer 4 Sellaphora rexii Potapova & Ponader 1 Sellaphora seminulum (Grunow) Mann 6 Sellaphora sp. 1 1 Sellaphora sp. 2 1 Sellaphora sp. 3 1 Sellaphora sp. 4 1 Sellaphora sp. 5 1 Sellaphora sp. 6 1 Simonsenia delognei (Grunow) Lange-Bertalot 1 Stauroneis acuta Smith 2 Stauroneis anceps Ehrenberg 2 Stauroneis gracilis Ehrenberg 1 Stauroneis indubitabilis Lange-Bertalot & Genkal 2 Stauroneis kriegeri Patrick 6 Stauroneis smithii Grunow 10 Stauroneis sp. 1 6 Stauroneis sp. 2 1 Stauroneis sp. 3 2 Stauroneis sp. 4 1 Stauroneis thermicola (Petersen) Lund 6 Staurosira construens Ehrenberg 12 Staurosira construens var. venter (Ehrenberg) Hamilton 4 Staurosira sp.1 1 Staurosirella leptostauron (Ehrenberg) Williams et Round 4 Staurosirella pinnata (Ehrenberg) Williams et Round 8 Stenopterobia curvula (Smith) Krammer 1 Stenopterobia delicatissma (Lewis) Brébisson 3 Stephanodiscus hantzschii Grunow 7 Stephanodiscus minutulus (Kützing) Cleve et Möller 9 Surirella amphioxys Smith 11 Surirella angusta Kützing 17 Surirella biseriata Brébisson 1 Surirella brebissonii var. kuetzingii Krammer et Lange-Bertalot 10 Surirella elegans Ehrenberg 1

Surirella lacrimula English 34 Surirella minuta Brébisson 1 Surirella pinnata Smith 10 Surirella sp. 1 1 Surirella splendida (Ehrenberg) Kützing 1 Surirella suecica Grunow ex Van Heurck 7 Surirella tenera Gregory 4 Synedra acus Kützing 7 Synedra acus var. angustissima Grunow 3 Synedra delicatissima Smith 1 Synedra parasitica (Smith) Hustedt 1 Synedra rumpens Kützing 17 Synedra socia Wallace 10 Synedra ulna (Nitzsch) Ehrenberg 37 Synedra ulna var. ramesi (Héribaud) Hustedt 13 Tabellaria fenestrata (Lyngbye) Kützing 7 Tabellaria flocculosa (Roth) Kützing 25 Tabularia fasciculata (Agardh) Williams et Round 1 Thalassiosira lacustris (Grunow) Hasle 5 Thalassiosira weissflogii (Grunow) Fryxell et Hasle 7 Tryblionella aerophila (Hustedt) Mann 5 Tryblionella apiculata Gregory 18 Tryblionella coarctata (Grunow) Mann 1 Tryblionella debilis Arnott 6 Tryblionella levidensis Smith 4

LITERATUE CITED

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