Density data for Lake Erie benthic invertebrate assemblages from 1930 to 2019

Benthic invertebrates are important trophic links in food webs and useful
bioindicators of environmental conditions, but long-term benthic organism
abundance data across broad geographic areas are rare, and historic data
sets are often not readily accessible. This data set for a companion paper
by Karatayev et al. (2022) provides densities of benthic
macroinvertebrates collected from 1930 to 2019 during surveys in Lake
Erie, a Laurentian Great Lake. The surveys were funded by the governments
of the United States and Canada to investigate the status and changes in
benthic community. From the total of 21 lake- and basin-wide benthic
surveys conducted in Lake Erie from 1929 to 2019, we were able to acquire
data for 17 surveys, including species-level data for 10 surveys and data
by higher taxonomic groups for 7 surveys. Our amassed Lake Erie dataset
includes data from 11 surveys (including 5 with species-level data)
conducted in the western basin in 1930–2019, 7 surveys (6 with
species-level data) in the central basin, and 8 surveys (7 with
species-level data) in the eastern basin (1973–2019). This Lake Erie
dataset represents the most extensive temporal dataset of benthic
invertebrates available for any of the Laurentian Great Lakes. Benthic
samples were collected using Ponar or Shipek bottom dredges and taxa
densities were calculated as individuals per m2 using the area of the
dredge. Density data are provided for taxa in the Annelida, Arthropoda,
Mollusca, Cnidaria, Nemertea, and Platyhelminthes phyla. Current taxonomy
was used for most groups, but in a few cases, older taxonomic names were
used for consistency with historical data. Analysis of this dataset
indicated that eutrophication, water quality improvement, and dreissenid
introduction were the major drivers of changes in the benthic community in
the western basin, while hypoxia was a major factor in the central basin,
and dreissenid introduction was most important in the eastern basin. The
previously diverse benthic community of the western basin has changed
dramatically over 90 years, transitioning from a diverse benthic species
assemblage indicative of good water quality in the 1930s to a one of low-
diversity assemblage dominated by oligochaetes and other
pollution-tolerant species in the 1960s, followed by recovery in the early
2000s to a state similar to that reported in 1930. In contrast, the
central basin benthic community has over the past 60 years been
consistently dominated by low oxygen-tolerant taxa, signifying the
persistence of hypoxia. The eastern basin community changed dramatically
in recent decades, with the disappearance of Diporeia after the
introduction of Dreissena in the 1990s and more recent declines in
oligochaetes, amphipods, gastropods, sphaeriid clams, and leeches.
Considering the rarity of high taxonomic resolution long-term benthic data
for lake ecosystems, this data set could be useful to explore broader
aspects of ecological theory, including effects of eutrophication,
hypoxia, invasive species, and other factors on community organization,
phylogenetic and functional diversity, and spatial and temporal scales of
variation in community structure. In addition, the data set could be
useful for studies on individual species including abundance and
distribution, species co-occurrence, and how the patterns of dominance and
rarity change over space and time. Use of this data set for academic or
educational purposes is encouraged. In doing so, we kindly request the
data source be properly cited using the title of this dataset, the names
of the authors, the year of publication, and the link to Dryad.