2002 Progress Report: Testing Indicators of Coastal Ecosystem Integrity Using Fish and Macroinvertebrates

EPA Grant Number: R828675C003
Subproject: this is subproject number 003 , established and managed by the Center Director under grant R828675
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).

Center: EAGLES - Great Lakes Environmental Indicators Project
Center Director: Niemi, Gerald J.
Title: Testing Indicators of Coastal Ecosystem Integrity Using Fish and Macroinvertebrates
Investigators: Johnson, Lucinda , Brazner, John , Breneman, Dan , Ciborowski, Jan , Hrabik, Thomas , Kelly, John R. , Morrice, John , Richards, Carl , Scharold, Jill , Sierszen, Michael , Tanner, Dan , Trebitz, Anett , Yurista, Peder
Current Investigators: Johnson, Lucinda , Brady, Valerie J , Breneman, Dan , Ciborowski, Jan , Hrabik, Thomas , Kelly, John R. , Morrice, John , Richards, Carl , Scharold, Jill , Schuldt, Jeffrey A. , Sierszen, Michael , Tanner, Dan , Trebitz, Anett , Yurista, Peder
Institution: University of Minnesota , U.S. Environmental Protection Agency , University of Windsor
Current Institution: University of Minnesota , Minnesota Sea Grant College Program , U.S. Environmental Protection Agency , University of Windsor , University of Wisconsin - Green Bay
EPA Project Officer: Packard, Benjamin H
Project Period: January 10, 2001 through January 9, 2005 (Extended to January 9, 2006)
Project Period Covered by this Report: January 10, 2001 through January 9, 2002
RFA: Environmental Indicators in the Estuarine Environment Research Program (2000) RFA Text |  Recipients Lists
Research Category: Ecological Indicators/Assessment/Restoration , Water , Ecosystems

Objective:

The objective of this research project is to evaluate and integrate indicators across multiple spatial scales. We will employ a multitiered sampling and modeling strategy to integrate data collected at regional scales via satellite imagery, local scales, and site scales via field sampling. These data will be used to identify indicators at each scale that reflect critical ecosystem process or state variables related to the integrity and sustainability of those ecosystems. We will test indicators representing fundamental driving variables and processes at multiple spatial scales, and integrate them into a system for identifying positive or negative trends in the condition of ecosystems in coastal regions of the Great Lakes. The specific objectives of our research project are to: (1) evaluate the applicability of State-of-the-Lake Ecosystem Conference (SOLEC)-derived and complementary indicators in the context of the ecosystem types found in the Great Lakes coastal region; (2) rigorously test the efficacy of a suite of indicators across the range of habitats within the Great Lakes coastal system; and (3) recommend indicators of specific ecological conditions keyed to assessment endpoints and stressors in the Great Lakes coastal region.

Progress Summary:

A total of 67 sites have been sampled across five geomorphic units (see Table 1). During the 2002 season, a total of 59 sites were visited (areas ranging from 4 ha up to 20 km2); sites were rejected in the field due to low water levels, lack of access, and denial of access by landowners. Sampling protocols called for fish to be sampled using a combination of fyke nets (a maximum of 4 arrays set at 0.5-1-m depth for 48 hours) and trawls (open water habitats at 5- and 10-m depths). Invertebrates were sampled using D-frame nets and cores at 2-m depths in shallow water, and via Ponar grab samplers and cores at the deepest point in wetlands and at 5 m and 10 m in open water sites (high energy and embayments). More than 35,000 fish were identified in 2002. Data have been entered and checked for quality control, and data analysis is in progress.

A total of 1,794 invertebrate samples were collected in 2002; sample processing is in progress and is approximately 50 percent complete. A large suite of physical water column and habitat variables was collected at fyke net and invertebrate sample points, as well as across the entire sampling unit. These data have been entered and currently are undergoing quality control checks.

Our review of preliminary information collected from pilot-season efforts revealed that no data were being collected at the level of the entire sampling unit by any of the aquatic groups. Therefore, in 2002, we initiated a sampling protocol at the unit scale to assess: landscape context (surrounding land use and cover), morphometry, disturbances (hydrologic alterations, shoreline structures), human uses (recreation, other development), habitat diversity and structure, bathymetry, and macrophyte distributions. These observations were made in parallel to data collected at fyke net locations and invertebrate sample points.

Table 1. Total Number of Sites Sampled to Date.

 
2001
2001
High Energy (HE)
4
11
Embayment (EB)
3
4
Protected Wetland (PW)
1
8
Riverine Wetland (RW)
3
17
Lacustrine Wetland (LW)
1
15
Total
12
55


Comparison of 24-Versus 48-Hour Fyke Net Protocol. One of the questions regarding the use of fyke nets for characterizing fish communities is whether an adequate representation can be obtained from a 24-hour fyke net set instead of a full 48 hours. Using our 2002 data, we have contrasted community structure metrics derived from 24- versus 48-hour fyke net sets, and quantified the possible effect of geomorphic types (wetland type, high energy, or embayment) on the results. An important question is how similar the catches are to one another, not just in terms of total numbers or presence/absence of various species, but as representatives of the total site community. We have used a variety of approaches to assess this question. First, we examined the number of additional fish species captured when nets were set for 48 hours. Overall, only 2-3 additional fish taxa were captured in 48-hour sets as compared to 24-hour net sets (see Table 2).

Table 2. Comparison of Fish Species Captured During 24-Versus 48-Hour Fyke Net Set.

Type # Sites
Mean # Taxa 24 h
Mean # Taxa 48 h
# Taxa Added
% Taxa Added
LW 15
13.53
16.4
2.87
17
EB 4
9.25
11.75
2.5
20.8
HE 19
7.95
10.05
2.1
18.22
PW 8
10.38
13
2.62
18.29
RW 20
12.15
14.95
2.8
18.26


Using ordinations, we examined the community similarity in 24- versus 48-hour sets. Nonmetric multidimensional scaling (NMDS) ordinations were performed using PC-ORD software. To correct for differential fishing effort, ordinations were conducted on fish catches as proportions rather than as abundances. There were sufficient sites sampled to ordinate each geomorphic type except embayments. For each unit type, we ran two ordinations: one that compared the 24-hour catch with the total 48-hour catch, and one that compared the Day 1 catch with the Day 2 catch (i.e., those fish caught only on the second day). In general, fyke net catches from the same site were similar to each other. As expected, the 24-hour versus the 48-hour catches were more similar to each other than were the Day 1 versus Day 2 catches.

We then examined how differently the various catches plotted on the ordinations. First, we examined whether catch pairs plotted more closely to each other than to a different site. For all sites, the 24-hour versus 48-hour catch pairs plotted more closely to each other than to other sites. The Day 1 versus Day 2 catch pairs were more likely to plot closer to another site than to each other only at some high-energy (32 percent) and riverine (35 percent) wetland site types. We also examined whether vectors drawn between catch pairs (straight lines connecting the two data points) intersected vectors from other site pairs for each of the three graph orientations. There were very few vector intersections in most ordinations. Again, Day 1 versus Day 2 catches at high-energy and river-influenced wetland site types displayed the largest number of intersections, but represented 25 percent or fewer of the total data pairs.

Finally, Pearson correlations were conducted on the plot locations of site catch pairs for each of the first two ordination axes. Correlations were high, 0.95 and higher, for 24-hour versus 48- hour catch pairs. Correlations for Day 1 versus Day 2 catch-pair ordinations were never lower than 0.77. Lacustrine wetland sites had the lowest catch-pair correlations on the main axis. From these results, we have concluded that 24-hour net sets are adequate for characterizing the dominant species and relative community composition at a site. To ensure that these trends pertain to all geomorphic sites, we will sample additional protected wetlands and embayments in 2003 using the 48-hour protocol, and will rerun these analyses for those unit types. For other unit types, we will reduce our sampling effort to a 24-hour set, unless fewer than 100 fish are captured, at which time we will deploy nets for an additional 24 hours.

Relative Influence of Landscape Characteristics and Anthropogenic Stress on Fish Communities in Great Lakes Coastal Wetlands. We evaluated the fish communities in 43 wetlands ordinated along gradients of anthropogenic stress from the U.S. coastal margins of the five Great Lakes. To select sites, we used principal components analysis to summarize the influence of 214 geographic information systems (GIS)-based environmental and human disturbance variables for 731 segment sheds across the Great Lakes basin. The wetlands that we sampled spanned the resultant stress scales. Fish were sampled using 48-hour fyke net sets during summer 2002. For analyses, sites were separated into northern and southern groupings due to latitudinal influences on fish community composition. Ordinations of fish relative abundances with the independent variables accounted for more than 60 percent of observed variation in the first three axes for both northern and southern sites. Different types of wetlands (lacustrine, protected, or river influenced) did not appear to support distinctive fish communities.

Both northern and southern wetlands supporting communities with high nonindigenous fish species richness were correlated with land uses and environmental variables characteristic of human disturbance and agricultural activities. We propose that the number of nonindigenous fish taxa is a robust indicator of the influence of anthropogenic stress that applies to a broad range of latitudes and geomorphic classes of wetlands.

The Invasibility of Stressed Sites by Exotic Benthic Macroinvertebrates in the Great Lakes: A Test of Hypotheses Using Echinogammarus ischnus. Two contrasting hypotheses regarding the invasibility of sites by exotic species have been proposed by previous studies. One hypothesis proposed that biotic resistance against exotic species establishment is greater in intact communities than in those disturbed by human activities. However, it also has been suggested that if abiotic conditions are appropriate, invasion is likely, regardless of the biota already present. We tested these hypotheses by investigating the presence of E. ischnus, an exotic amphipod, at sites influenced by varying degrees of anthropogenic stress. Thirty sites supporting Gammarus fasciatus, a common amphipod with habitat preferences similar to E. ischnus, were evaluated. The presence/absence of E. ischnus was ordinated across ranges of each of five different stressor variables: total nutrient input, N + P load, areas of agricultural land, human population density, and overall pollution loading. Run tests were used to determine randomness of E. ischnus occurrence at these sites ordinated from low to high stress. None of the five tests showed a significant association between the presence of E. ischnus and the amount of stress. This is consistent with the expectations of these hypotheses. This method can potentially be used to evaluate the amount and type of stress associated with invaders, as well as invader occurrence at stressed sites.

Future Activities:

The 2003 field season will begin with "boot camp" in Green Bay, Wisconsin, in the first week of June. Following this training week, four crews will be in the field from June-September sampling 63 sites. Forty-three of these are new sites, including 14 embayments, 5 high-energy shorelines, 5 lacustrine wetlands, 12 protected wetlands, and 7 river-influenced wetlands. These sites were selected to maximize both coverage of the stressor gradients and overlap with other subprojects. Twenty sites, four sites of each geomorphic type from among the 2002 sites, will be revisited to provide data on interannual variation. Laboratory work on invertebrate sample processing and identification will continue, as will data entry, data quality assessment, and data analyses. We will be giving several presentations on our preliminary results, including talks in the Great Lakes Ecological Indicators (GLEI) special session at the International Association of Great Lakes Research meeting, and a talk at the North American Benthological Society Meeting.

Journal Articles:

No journal articles submitted with this report: View all 36 publications for this subproject

Supplemental Keywords:

Great Lakes, coastal wetlands, environmental indicators, community, fish, macroinvertebrate, high-energy shorelines, embayment., RFA, Scientific Discipline, ENVIRONMENTAL MANAGEMENT, Geographic Area, ECOSYSTEMS, Water, Ecosystem Protection/Environmental Exposure & Risk, Nutrients, Ecosystem/Assessment/Indicators, Ecosystem Protection, exploratory research environmental biology, Ecological Effects - Environmental Exposure & Risk, Ecological Monitoring, Environmental Monitoring, Ecological Risk Assessment, Ecology and Ecosystems, Great Lakes, Ecological Indicators, Risk Assessment, coastal ecosystem, diatoms, ecological condition, aquatic ecosystem, hydrological stability, nutrient supply, nutrient transport, fish, ecosystem assessment, hierarchically structured indicators, wetland vegetation, environmental stressor, hydrological, macroinvertebrates, coastal environments, environmental consequences, ecological assessment, ecosystem indicators, estuarine ecosystems, nutrient stress, aquatic ecosystems, toxic environmental contaminants, water quality, ecosystem stress

Relevant Websites:

http://glei.nrri.umn.edu Exit

Progress and Final Reports:

Original Abstract
  • 2001
  • 2003 Progress Report
  • 2004 Progress Report
  • Final Report

  • Main Center Abstract and Reports:

    R828675    EAGLES - Great Lakes Environmental Indicators Project

    Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
    R828675C001 Great Lakes Diatom and Water Quality Indicators
    R828675C002 Vegetative Indicators of Condition, Integrity, and Sustainability of Great Lakes Coastal Wetlands
    R828675C003 Testing Indicators of Coastal Ecosystem Integrity Using Fish and Macroinvertebrates
    R828675C004 Development and Assessment of Environmental Indicators Based on Birds and Amphibians in the Great Lakes Basin
    R828675C005 Development and Evaluation of Chemical Indicators for Monitoring Ecological Risk