Kansas Aquatic Gap: Web Interface User’s Guide

(updated 8 April 2009)

 

Purpose:  The main products of the Kansas Aquatic Gap project are a geodatabase and web interface.  These tools allow users to view (1) habitat parameters for stream valley segments, (2) sampling locations and (3) predicted distributions of fish and mussel species in Kansas.  In addition, the web interface includes a link to a database search engine that allows users to query and download biological data into a spreadsheet friendly format (.csv files).  The overarching goal of this database system is to allow researchers access to spatial data that can be used to test research questions, evaluate sampling efficiency and guide conservation planning.

 

Background: The Kansas Aquatic Gap project combines large-scale stream habitat data with biological data to construct models that predict the occurrences of fish and mussel species in Kansas streams.  Although there are a number of large databases with distributional data for fish and mussels in Kansas (i.e., Kansas Department of Wildlife and Conservation Stream Team surveys, University of Kansas and Sternberg Museum of Natural History collection records), these collection sites represent only a small fraction of the streams habitat in the state.  As such, developing species management plans requires an extrapolation of these collection records to areas that have not been sampled.  For example, critical habitat for a species is usually subjectively determined by including entire watersheds from which a species in known to occur.  Although this process can works, it becomes difficult to project potential habitat for a species that is patchily distributed across the landscape.  Kansas Aquatic Gap used a combination of hydrologic tools associated with a geographic information system (GIS) in combination with robust predictive modeling approaches that use habitat characteristics of streams and their watersheds to predict distributions of fishes and mussels.  Because this approach used both species distributional data and physical attributes of streams and watersheds, predicted distributions of species were based on objective criteria.  The end product includes a geodatabase and interactive maps that can be used to evaluate the conservation status of any stream or river reach in the state.  In addition, the construction of relational databases will provide a resource to begin evaluating factors that are associated with the disappearance of imperiled species.

 

Methods: The majority of the species (fish and mussel) occurrence records in the KS Aquatic Gap database are from the Kansas Department of Wildlife and Parks Stream Team surveys.  In addition, as part of the Kansas Aquatic Gap Program we have compiled data from natural history museums, most of which were from the KU and Sternberg collections.  We also have records from six other major museums that have records from Kansas waters and have compiled mussel data from the Kansas Department of Health and Environment.  From these data, we have mapped the distribution of collection records in Kansas by 8, 11, and 14-digit HUCs.  GIS-derived characteristics of the stream network were calculated from a modified version of the National Hydrography Dataset (NHD; USGS 1997).  In this data layer, stream segments were characterized by a variety of biologically relevant attributes including stream slope, stream order, link magnitude and sinuosity.  This stream network data layer was used to construct a watershed data layer for every stream segment in the state of Kansas (> 50,000 watersheds).  Land use for these watersheds based on the NLCD (USGS 1992) and geology of each watersheds from the STATSGO database (NRCS 1994). 

 

Models of species distributions were conducted with classification trees (CT) and the maximum entropy method (Maxent).  The output from these models is a prediction of the occurrence or likelihood of occurrence of each species for each stream segment in the state.  Stream segments are line features in a GIS that represent stream sections between tributary confluences.  Classification trees are a simple but robust way to classify ecological groups bases on a suit of explanatory variables (De’ath and Fabricius 2000).  We only used KDWP stream survey data (approximately 1,200 community collections) in the construction of CT because sampling effort was standardized and species absences resulted from an inability to capture that species after and extended effort.  Although detection probability was not perfect, we felt confident in grouping sites based on the presence or absence of a species assuming that if a species was not detected it was likely rare at best.  Predicted distributions of fishes based on CT explain variation of a single response variable (i.e., species presence or absence) by repeatedly splitting the data into more homogeneous gropus, using combinations of explanatory variables (i.e., stream habitat) that may be categorical and/or numeric.  Each group is characterized by a typical value of the response variable, the number of observations in the group, and the values of the explanatory variables that define it. 

            In addition to CT modeling, we used Maxent to construct models based on species occurrences only.  Maxent is a general-purpose machine learning method with a simple and precise mathematical formulation, and it has a number of aspects that make it well-suited for species distribution modeling (Phillips et al. 2006).  Because Maxent only relies on presence only data, we used our entire database on fish species distributions (approximately 3,400 community collections); albeit we only used the KDWP stream survey data to model mussel species distributions with Maxent.  The relative importance of stream habitat variables in these models is assessed by evaluating the performance of the model when the variable of interest is left out.  Caution is suggested in interpreting these variable weightings because this method does not account for potential interactions among variables. 

 

Summary of Results: Relevant habitat attributes were defined for 55,295 stream segments in the state of Kansas.  Because the original National Hydrography Dataset (NHD; USGS 1997) overestimated the occurrence of streams with viable fish and mussel habitat, we excluded 1st order streams from our analyses and capture of watershed land cover and geologic data.  Habitats from 2nd order and greater streams include catchment geology, catchment land cover and stream segment or network attributes (Appendix I). 

            Predicted distributions were generated for 119 fish and 43 mussel species.  Classification tree analysis was only used for fish species that occurred at > 4 sites (N = 99 species).  Of the 99 species modeled, 58 generated significant models (Appendix II).  As an example of insignificant models, many common species resulted in models that predicted them to occur everywhere (e.g., Lepomis cyanellus) and rare species were predicted to always be absent (e.g., Ambloplites rupestris); these models were not significantly different from random.  Classification tree results for each species with a significant model are provided in Appendix III.

            MaxEnt was used to predict the probability of occurrences for both fish and mussel species.  Mean variable importance across fish species was greatest for geographic coordinates, reflecting regional differences in fish species distributions (Appendix IV).  For mussels, easting and stream link (an indicator of catchment size) were, on average, weighted the heaviest among predictor variables (Appendix V).           

 

Literature Cited

De’ath, G. and K.E. Fabricius.  2000.  Classification and regression trees: a powerful yet simple technique for ecological data analysis.  Ecology 81:3178-3192.

Gido, K.B., J.A. Falke, R.M. Oakes, and K.J. Hase.  2006.  Fish-habitat relationships across spatial scales in prairie streams.  Hughes, B., P. Seelbach, and L. Wang (eds.) Influences of Landscapes on Stream Habitats and Biological Communities, American Fisheries Society Symposium 48:265–285.

NRCS (Natural Resources Conservation Service). 1994. State soil geographic (STATSGO) database for Kansas. NRCS, Fort Worth, Texas.

Oakes, R.M., K. B. Gido, J.A. Falke, J.D. Olden, and B.L. Brock.  2005. Predictive modeling of stream fish assemblages in the Great Plains.  Ecology of Freshwater Fishes 14:361-374.

Phillips, S.J., R.P. Anderson, R.E. Schapire.  2006.  Maximum entropy modeling of species geographic distributions.  Ecological Modelling 190: 231–259.

USGS (U.S. Geological Survey). 1997. National hydrography dataset. USGS, Reston, Virginia.

USGS (U.S. Geological Survey).  1998.  National Land Cover Data (NLCD).  USGS, Reston, Virginia.


 

Instructions for the web interface

 

1) Connect to site in web browser: http://www.konza.ksu.edu/fishecology/

2) Users can navigate by checking available layers and using GIS tools.  In addition, there are links to other web resources and this user’s guide

3) Viewing available layers

            a) There are six main categories of GIS layers that can be viewed.  Some of these only appear when zoomed in (County boundaries, TSR, and HUCs).

            b) For overlapping layers (e.g., stream habitat and predicted distributions) you can only view one item at a time.  All other items must be unchecked.  For stream segment habitat characteristics, species distributions, and results from ecological niche modeling, you need to check the main box and box within that menu that you would like to view.

            c) Layer categories


                        i) Boundaries – contains county boundaries, hydrologic units and township, section and range

 

                        ii) Field Sites – point data of sample locations of KDWP and habitat variables taken at those sites

 

                        iii) Stream segments – Habitat information quantified for each stream segment.  Variable descriptions are given in Appendix I.

 

                        iv)  CT predictions and occurrences – This layer includes predicted occurrence, based on classification tree (CT) analysis, of fish species for each stream segment (indicated by dark green) and predicted absence (indicated by grey).  Observed presences of species are indicated by red.  Checking the first box in the drop down list “CT Predictions and Occurrences” is used in concert with the information tool to show a species list with predicted occurrences and absences for a stream segment.

 

                       

 

v) MaxEnt Predictions – This layer includes predicted occurrence, based on Maxent analysis, of fish species for each stream segment.  Dark green indicates a probability of occurrence > 50%, light green 10% - 50% and grey < 10%. 

 

 

4) Using GIS tools

a)      Zoom in and out, drag screen, full extent view, magnifier and measure tools help you maximize viewing of data layers and are self-explainatory.

b)      Identify tool will allow you to capture data from individual stream segments, but the information you acquire will depend on the layers that are selected.

a.       Stream segment habitat attributes – left click on identify tool on tool bar.  Move hand to stream segment that you want to view data and left click.  For example, in the top figure below, a valley segment on Wildcat Creek has been selected.  In the bottom figure, the percent grassland for that segment can be viewed by clicking on the expand button (note that the stream segment attribute Grassland (%) is highlighted).  In some cases, you might have to drag the mouse over the results to expand the table.

b.      Species predictions – predicted occurrences for the fish community can be viewed for each stream segment with the identification tool.  However, you must have the Community predictions box check, rather than individual species to view the entire community (See below)

 

5) Web links (Advanced Query)

a)      A query of collection records can be made through the Advanced Query link at the top of the Aquatic Gap web interface.  This search engine allows users to query the KDWP database by species names, stream name, county, HUC units and can constrain the search by stream size and year of collection.  Leave field blank if you want an unconstrained search.  This search engine also provides recognition of species names so users do not need to know exact spelling. For example, I have selected a query of collections from Pottawatomie county

b)      After selecting a search constraints, click “send” and a page that asks you to further constrain your search.  Check any boxes you want or select all records (e.g., species or stream sizes).

c)      View individual records or download all to .csv file.

 


 

Appendix I:  Habitat attributes quantified for stream segments and used in ecological niche models for Kansas fish and mussel species.

Category

Abbreviation

Descritpion

Catchment Geology

C_AWC

Available water capacity

C_BD

Bulk density of soils

C_KFACT

Soil erodibility factor

C_OM

Organic matter content of soils

C_PERM

Soil permeability

C_ROCKDEP

Depth to bedrock

C_SLOPE

Field slope

C_TFACT

Soil loss tolerance factor

C_WEG

Wind erodibility group

C_WTDEP

Water table depth

Stream segment

DLINK

Link magnitude of downstream segment

DOWNORDER

 Strahler order of downstream segment

GRADRCHMKM

Gradient (% change over length of segment)

LINK

Link magnitude (no. of stream segments upstream of a given stream segment)

STRAHLER

Strahler order of stream segment

MAX_ELEV

Maximum elevation

SEGMDPTX

UTM easting coordinate

SEGMDPTY

UTM northing coordinate

SHD_AREA_1

Drainage area above segment

Catchment land cover

PCT_CULTIV

Agricultural land

PCT_FOREST

Forested land

PCT_GRASS

Rangeland

PCT_SHRUB

Shrubland

PCT_URBAN

Urban land

PCT_WETLAN

Wetlands

 

P_OPENH2O

Water

 


 

Appendix II.  Summary results from classification tree analysis to predict fish species occurrence in Kansas streams.

Species

Occurrences

Classification success

Correct present

Correct absent

Cohen's Κ

P

Ambloplites rupestris

6

0.995

predicted to always be absent

Ameiurus melas

392

0.800

0.666

0.871

0.549

<0.001

Ameiurus natalis

450

0.719

0.578

0.812

0.399

<0.001

Aplodinotus grunniens

177

0.862

0.119

0.999

0.183

<0.001

Campostoma anomalum

676

0.827

0.905

0.711

0.632

<0.001

Carassius auratus

30

0.974

predicted to always be absent

Carpiodes carpio

268

0.847

0.440

0.972

0.493

<0.001

Carpiodes cyprinus

54

0.953

predicted to always be absent

Catostomus commersonii

176

0.953

0.818

0.978

0.817

<0.001

Cottus carolinae

4

0.996

predicted to always be absent

Ctenopharyngodon idella

12

0.989

predicted to always be absent

Cycleptus elongatus

6

0.997

0.667

0.999

0.726

<0.001

Cyprinella camura

60

0.979

0.667

0.996

0.758

<0.001

Cyprinus carpio

560

0.720

0.650

0.789

0.439

<0.001

Cyprinella lutrensis

845

0.874

0.943

0.675

0.652

<0.001

Cyprinella spiloptera

6

0.997

0.833

0.998

0.768

<0.001

Dorosoma cepedianum

282

0.828

0.422

0.963

0.455

<0.001

Erimystax x-punctatus

10

0.997

0.800

0.999

0.841

<0.001

Etheostoma blennioides

13

0.993

0.538

0.998

0.633

<0.001

Etheostoma chlorosoma

9

0.992

predicted to always be absent

Etheostoma cragini

141

0.942

0.759

0.968

0.731

<0.001

Etheostoma flabellare

41

0.964

predicted to always be absent

Etheostoma gracile

4

0.996

predicted to always be absent

Etheostoma nigrum

79

0.953

0.354

0.997

0.489

<0.001

Etheostoma spectabile

524

0.883

0.906

0.863

0.766

<0.001

Etheostoma stigmaeum

3

0.997

predicted to always be absent

Etheostoma whipplei

18

0.984

predicted to always be absent

Etheostoma zonale

8

0.997

0.875

0.998

0.822

<0.001

Etheostoma zonale

239

0.936

0.837

0.962

0.805

<0.001

Fundulus notatus

150

0.934

0.747

0.963

0.711

<0.001

Gambusia affinis

400

0.833

0.740

0.883

0.630

<0.001

Hybognathus hankinsoni

10

0.991

predicted to always be absent

Hybognathus placitus

45

0.985

0.689

0.997

0.777

<0.001

Hypentelium nigricans

7

0.994

predicted to always be absent

Ictiobus bubalus

120

0.913

0.275

0.988

0.363

<0.001

Ictiobus cyprinellus

41

0.964

predicted to always be absent

Ictiobus niger

59

0.948

predicted to always be absent

Ictalurus punctatus

577

0.845

0.868

0.821

0.690

<0.001

Labiesthes sicculus

153

0.895

0.588

0.943

0.542

<0.001

Lepomis cyanellus

915

0.805

predicted to occur at all locations

Lepomis gulosus

57

0.950

predicted to always be absent

Lepomis humilis

475

0.736

0.632

0.811

0.449

<0.001

Lepomis macrochirus

527

0.741

0.698

0.779

0.478

<0.001

Lepomis megalotis

368

0.857

0.766

0.900

0.670

<0.001

Lepomis microlophus

16

0.986

predicted to always be absent

Lepisosteus oculatus

5

0.996

predicted to always be absent

Lepisosteus osseus

160

0.891

0.375

0.975

0.437

<0.001

Lepisosteus platostomus

30

0.974

predicted to always be absent

Luxilus cardinalis

36

0.988

0.750

0.995

0.788

<0.001

Luxilus cornutus

103

0.965

0.738

0.987

0.773

<0.001

Lythrurus umbratilis

264

0.891

0.765

0.929

0.694

<0.001

Lythrurus umbratilis

12

0.998

0.833

1.000

0.908

<0.001

Macrohybopsis storeiana

16

0.986

predicted to always be absent

Macrohybopsis tetranema

16

0.986

predicted to always be absent

Menidia beryllina

8

0.993

predicted to always be absent

Micropterus dolomieu

11

0.990

predicted to always be absent

Micropterus punctulatus

73

0.964

0.575

0.991

0.653

<0.001

Micropterus salmoides

604

0.697

0.808

0.570

0.383

<0.001

Minytrema melanops

39

0.966

predicted to always be absent

Morone americana

26

0.977

predicted to always be absent

Morone chryspos

72

0.946

0.222

0.995

0.325

<0.001

Morone hybrid

9

0.992

predicted to always be absent

Moxostoma carinatum

4

0.996

predicted to always be absent

Moxostoma erythrurum

154

0.888

0.584

0.936

0.522

<0.001

Moxostoma macrolepidotum

114

0.927

0.360

0.990

0.464

<0.001

Nocomis asper

5

0.996

predicted to always be absent

Nocomis biguttatus

9

0.992

predicted to always be absent

Notropis athernoides

97

0.970

0.722

0.993

0.789

<0.001

Notropis bairdi

4

0.996

predicted to always be absent

Notropis boops

21

0.996

0.810

0.999

0.870

<0.001

Notropis buchanani

22

0.981

predicted to always be absent

Notemigonus crysoleucas

117

0.897

predicted to always be absent

Notropis dorsalis

18

0.984

predicted to always be absent

Noturus exilis

117

0.966

0.786

0.986

0.806

<0.001

Noturus flavus

142

0.929

0.613

0.974

0.643

<0.001

Noturus nocturnus

43

0.977

0.395

1.000

0.557

<0.001

Notropis nubilus

5

0.998

1.000

0.998

0.832

<0.001

Notropis percobromus

77

0.966

0.584

0.993

0.680

<0.001

Noturus placidus

5

0.996

predicted to always be absent

Notropis stramineus

538

0.850

0.812

0.883

0.697

<0.001

Notropis topeka

32

0.972

predicted to always be absent

Notropis volucellus

35

0.981

0.543

0.995

0.624

<0.001

Percina caprodes

232

0.876

0.720

0.916

0.625

<0.001

Percina copelandi

40

0.965

predicted to always be absent

Percina phoxocephala

156

0.940

0.814

0.960

0.754

<0.001

Phenacobius mirabilis

507

0.773

0.759

0.784

0.542

<0.001

Phoxinus erythrogaster

36

0.986

0.667

0.996

0.743

<0.001

Pimephales notatus

503

0.849

0.859

0.841

0.695

<0.001

Pimephales promelas

521

0.835

0.814

0.852

0.667

<0.001

Pimephales tenellus

49

0.974

0.633

0.990

0.668

<0.001

Pimephales vigilax

223

0.908

0.641

0.973

0.677

<0.001

Pomoxis annularis

242

0.787

predicted to always be absent

Pomoxis nigromaculatus

43

0.962

predicted to always be absent

Pylodictis olivaris

292

0.860

0.801

0.880

0.650

<0.001

Sander canadensis

3

0.997

predicted to always be absent

Sander canadensis

10

0.991

predicted to always be absent

Sander vitreus

20

0.982

predicted to always be absent

Scaphirhynchus platorynchus

4

0.999

1.000

0.999

0.888

<0.001

Semotilus atromaculatus

356

0.896

0.871

0.908

0.763

<0.001


 


Appendix III:  Results of classification trees used to predict the occurrence of fish species in Kansas streams.  Predictor variables at each node represent habitat variables described in Appendix I. 

 

 

Ameiurus melas


 

Ameiurus natalis


 

Aplodinotus grunniens


 

Campostoma anomalum


 

Carpiodes carpio


 

Catostomus commersonii


 

Cycleptus elongatus


 

Cyprinella camura


 

Cyprinella lutrensis


 

Cyprinella spiloptera


 

Cyprinus carpio


 

Dorosoma cepedianum


 

Erimystax x-punctatus


 

Etheostoma blennioides


 

Etheostoma cragini


 

Etheostoma nigrum


 

Etheostoma spectabile


 

Etheostoma zonale


 

Fundulus kansae


 

Fundulus notatus


 

Gambusia affinis


 

Hybognathus placitus


 

Ictiobus bubalus


 

Ictalurus punctatus


 

Labiesthes sicculus


 

Lepomis humilis


 

Lepomis macrochirus


 

Lepomis megalotis


 

Lepisosteus osseus


 

Luxilus cardinalis


 

Luxilus cornutus


 

Lythrurus umbratilis


 

Macrhybopsis aestivalis


 

Micropterus punctulatus


 

Micropterus salmoides


 

Morone chrysops


 

Moxostoma erythrurum


 

Notropis athernoides


 

Notropis boops


Notropis nubilus


 

Notropis percobromus


 

Notropis stramineus


 

Notropis volucellus


 

Noturus exilis


 

Noturus flavus


 

Noturus nocturnus


 

Percina caprodes


 

Percina phoxocephala


 

Phenacobius mirabilis


 

Phoxinus erythrogaster


 

Pimephales notatus


 

Pimephales promelas


 

Pimephales tenellus


 

Pimephales vigilax


 

Pylodictis olivaris


 

Scaphirhynchus platorynchus


 

Semotilus atromaculatus


 


Appendix IV:  Results from maximum entropy (Maxent) niche modeling of fish species.  Variable importance, derived by evaluating the change in model performance when variable is left out.  Higher value indicates greater importance.

 

Species

C_AWC

C_BD

C_KFACT

C_OM

C_PERM

C_ROCKDEP

C_SLOPE

C_TFACT

C_WEG

C_WTDEP

Ambloplites rupestris

0.0

0.2

0.0

2.7

0.0

4.5

0.0

0.0

0.2

0.0

Ameiurus melas

1.3

0.7

0.2

5.4

1.3

0.4

4.9

6.4

1.3

0.7

Ameiurus natalis

2.0

2.9

0.2

0.7

2.2

2.4

3.6

2.3

2.7

1.0

Aplodinotus grunniens

0.0

1.2

8.3

2.0

3.6

4.5

0.8

1.8

1.4

2.5

Campostoma anomalum

1.0

1.4

0.0

0.0

6.7

10.2

2.7

3.5

0.8

4.0

Carassius auratus

0.1

0.0

0.1

1.2

0.3

0.6

10.6

6.5

0.0

0.1

Carpiodes carpio

0.0

1.7

0.0

2.8

2.7

5.2

2.1

16.2

2.0

2.6

Carpiodes cyprinus

0.0

0.2

2.4

0.0

0.3

14.7

2.8

30.0

0.2

0.2

Carpiodes velifer

0.0

0.1

0.0

0.0

0.0

3.8

0.2

2.7

0.0

0.0

Catostomus commersonii

0.3

2.9

0.8

0.5

1.0

1.0

2.3

0.4

1.0

3.2

Cottus carolinae

0.0

0.0

0.0

17.1

0.0

11.9

0.0

0.0

0.0

0.0

Ctenopharyngodon idella

0.0

0.0

0.0

4.3

0.9

29.5

0.0

27.9

0.0

4.3

Cycleptus elongatus

0.0

0.0

0.0

9.2

0.5

6.5

0.5

1.5

2.2

0.0

Cyprinella camura

0.0

0.2

1.0

0.4

0.1

0.0

1.3

0.6

0.6

8.7

Cyprinus carpio

0.0

0.6

0.0

1.3

0.7

14.5

0.0

16.2

0.0

0.7

Cyprinella lutrensis

0.0

3.1

3.9

0.0

0.0

0.0

22.7

0.0

0.0

7.2

Cyprinella spiloptera

1.2

0.3

0.0

0.5

0.6

6.4

0.5

0.0

0.1

0.0

Dorosoma cepedianum

0.9

0.0

3.5

12.8

2.9

8.8

6.9

4.1

1.5

1.1

Dorosoma petenense

0.0

4.0

0.0

1.2

0.0

9.1

0.0

1.0

5.6

0.6

Erimystax x-punctatus

0.0

0.0

1.4

0.0

0.0

0.5

0.1

0.0

0.6

27.8

Esox lucius

0.4

0.0

0.0

2.9

0.0

0.0

0.0

0.4

0.0

0.0

Etheostoma blennioides

0.0

0.0

1.2

3.2

0.0

0.1

0.1

0.0

0.3

1.4

Etheostoma chlorosoma

0.0

1.4

0.1

4.7

2.0

12.0

2.2

0.7

0.0

26.0

Etheostoma cragini

0.0

0.0

0.2

0.1

0.5

2.5

0.0

0.2

0.0

0.5

Etheostoma flabellare

0.9

0.0

0.9

1.2

0.3

3.9

2.9

25.5

2.1

1.7

Etheostoma gracile

0.0

2.0

0.0

2.8

0.6

0.2

0.0

0.0

0.0

0.0

Etheostoma nigrum

0.1

2.0

3.2

1.2

0.3

4.8

2.3

3.3

3.0

11.4

Etheostoma punctulatum

0.0

0.0

0.0

7.7

0.0

8.4

0.0

0.0

0.2

0.0

Etheostoma spectabile

0.0

4.0

1.0

0.1

2.2

12.9

0.3

3.0

0.0

8.5

Etheostoma stigmaeum

0.0

2.6

0.0

8.1

0.9

21.7

1.1

0.0

15.6

0.0

Etheostoma whipplei

0.3

0.0

0.6

0.0

0.5

0.5

0.2

3.8

0.0

10.4

Etheostoma zonale

0.0

0.2

1.3

0.8

0.0

0.1

0.5

0.0

0.0

4.9

Etheostoma zonale

0.7

0.3

0.3

1.9

1.1

0.7

3.5

1.5

6.6

0.4

Fundulus notatus

0.1

0.0

0.3

0.1

0.3

0.4

0.2

1.9

0.2

1.5

Gambusia affinis

0.6

0.2

0.0

0.0

0.4

2.0

16.8

0.9

1.5

0.1

Hiodon alosoides

0.0

0.1

0.0

0.5