A survey of the algal flora for a minimally polluted stream in southeastern Ohio was conducted over a two-year period (17 sampling dates) as part of an all-taxa biotic survey. Four algal categories were sampled: macroalgae (readily visible with the naked eye), microalgae (associated with macroalgae), erosional periphyton (microalgae from riffles), and depositional periphyton (microalgae from pools). A total of 217 infrageneric taxa were collected. There were 25 cyanobacteria, 74 chlorophytes, 6 chrysophytes, 3 cryptophytes, 86 diatoms, 4 dinophytes, 12 euglenophytes, 1 raphidophyte, 3 rhodophytes, and 3 tribophytes. A seasonal trend was observed in species richness; fall had the most taxa (136), followed by winter (107), summer (100), and spring (82). Approximately half of the taxa occurred in samples from more than one season, but only 15% were present year-round. Overall, species richness was not correlated to any stream parameter. However, diatom species richness was positively correlated to pH, and both diatom and soft-bodied algal richness were negatively affected by nutrient loading. For the soft-bodied algae, the microalgae category was the most species-rich followed by the depositional periphyton, erosional periphyton, and macroalgae. For the diatoms, the depositional periphyton had higher species richness than the erosional periphyton. Five diatom and 17 soft-bodied algal taxa previously unreported from the Unglaciated Western Alleghany Plateau were identified from this stream reach. This study highlights the need for multiple samplings in different seasons to capture the total species richness, since only a small fraction of the taxa were collected year-round and one third of the diatoms collected were rare.

Gravid females of Ligumia display marginal papillae to attract fish hosts for their parasitic larvae. In L. nasuta and L. subrostrata, the papillae move rapidly and synchronously, but we did not see L. recta's papillae move. The moving displays of L. nasuta and L. subrostrata attract fish, which readily attack displaying females, causing them to release glochidia onto the fish. Display frequency in L. nasuta and L. subrostrata slows in low light and stops in the dark. Ligumia recta displays both in the light and in the dark. High turbidity stops the displays of L. nasuta and L. subrostrata. Displaying females of L. nasuta and L. subrostrata move more at night than during the day, perhaps allowing them to display to different fish each day.

We conducted surveys of aquatic habitats during the spring and summer of 1995 in Canaan Valley, WV, to describe the diversity of aquatic habitats in the valley and identify issues that may threaten the viability of aquatic species. We assessed physical habitat and water chemistry of 126 ponds and 82 stream sites, and related habitat characteristics to landscape variables such as geology and terrain. Based on our analyses, we found two issues likely to affect the viability of aquatic populations in the valley. The first issue was acid rain and the extent to which it potentially limits the distribution of aquatic and semi-aquatic species, particularly in headwater portions of the watershed. We estimate that nearly 46%, or 56 kilometers of stream, had pH levels that would not support survival and reproduction of Salvelinuw fontinalis (brook trout), one of the most acid-tolerant fishes in the eastern US. The second issue was the influence of Castor canadensis (beaver) activity. In the Canaan Valley State Park portion of the valley, beaver have transformed 4.7 kilometers of stream (approximately 17% of the total) to pond habitat through their dam building. This has resulted in an increase in pond habitat, a decrease in stream habitat, and a fragmented stream network (i.e., beaver ponds dispersed among stream reaches). In addition, beaver have eliminated an undetermined amount of forested riparian area through their foraging activities. Depending on the perspective, beaver-mediated changes can be viewed as positive or negative. Increases in pond habitat may increase habitat heterogeneity with consequent increases in biological diversity. In contrast, flooding associated with beaver activity may eliminate lowland wetlands and associated species, create barriers to fish dispersal, and possibly contribute to low dissolved oxygen levels in the Blackwater River. We recommend that future management strategies for the wildlife refuge be viewed in the context of these two issues, and that the responses of multiple assemblages be incorporated in the design of refuge management plans.

We used local and landscape models to predict fish assemblages in the Great Swamp, NY, a region undergoing rapid development. Fish were surveyed across 17 sites. Fish-species richness, diversity, percent intolerant species, and IBI metrics for fish species richness, benthic insectivores, terete minnows, and dominant species were calculated. Local stream features were characterized and surrounding land cover/use was quantified at four different scales (reach, segment, network, and watershed). Regression analysis and multinomial cumulative logit models were used to predict how fish assemblages varied according to habitat characteristics. Within the local variables, pool variability predicted diversity and epifaunal substrate/available cover predicted percent intolerant species and IBI metrics for fsh species richness, benthic insectivores, and terete minnows. The scale of analysis influenced which landscape-level predictors measuring percent wetland, forest cover, or residential land use best explained diversity, percent intolerant species, and IBI metrics for benthic insectivores, terete minnows, and dominant species. Although no single model (local or landscape) best predicted assemblages, the land cover/use at the segment (100-m buffer for 1 km upstream) scale provides sufficient information about fish assemblages to support this scale as optimal for regional land-use planners. Our findings show that forest cover should be maintained to protect fish assemblages in the Great Swamp and development that alters stream-habitat heterogeneity should be curtailed.

We utilized microcosms that mimicked the rocky intertidal community to examine the predatory impacts of two introduced crab species, Carcinus maenas and Hemigrapsus sanguineus, on naturally occurring assemblages of organisms on rocks in the laboratory and in the field. The two crab species had similar consumption patterns causing significant declines in Semibalanus balanoides (barnacles), juvenile Mytilus edulis (mussels), Spirorbis sp. (polychaetes), and ephemeral algae. In both two-day and fourteen-day field experiments, the decline in S. balanoides in the H. sanguineus treatments was significantly greater than in the C. maenas treatments suggesting that H. sanguineus may have a higher per capita impact on barnacles than C. maenas. As H. sanguineus increases in abundance in northern New England, it may have greater impacts on prey species than C. maenas did when it became established.

An introduced population of Etheostoma blennioides (greenside darter) in the Susquehanna River drainage has rapidly expanded its range since its discovery in the late 1960s. Geochronology of collection data in the Susquehanna River drainage provides evidence for explosive dispersal and long-range movement patterns. We discuss the current status and distribution of E. blennioides in the drainage, and suggest that other Mid-Atlantic Slope drainages with low native-darter diversity are at risk of similar colonization events. Although the long-term effect of these invasive populations is as yet unknown, we suggest that they may pose serious threats to persistence of several unique members of the Atlantic Slope ichthyofauna, especially the critically imperiled Etheostoma sellare (Maryland darter).

Phoca groenlandica (harp seals) and Cystophora cristata (hooded seals), two species of ice-breeding seals, are being sighted more frequently onshore in the Gulf of Maine since 1990, but little is known about their behavior in this ecosystem. We obtained records of 904 ice-breeding seal stranding locations in the Gulf of Maine between 1996 and 2002 from NOAA Fisheries and used a geographic information system (GIS) to conduct group-wise comparisons by species (using non-parametric techniques), and to determine the predictors of high seal-stranding density (using ordinal logistic regression analysis). Compared to harp seals, hooded seals stranded closer to deep water, farther north, and near different intertidal shoreline types. Predictors of high seal-stranding density included being closer to an offshore basin, deep water, public land, and areas of lower human population. These results may reflect seal behavior and reporting bias.

Nocturnal activity and diurnal roosts of Myotis sodalis (Indiana bat) were studied during autumn swarming in 2000 near a hibernaculum in Bland County, VA. Bats were active in 9 habitats, using open deciduous forests more fequently, and developed lands, closed deciduous habitats, and mixed deciduous-evergreen habitats less frequently than would be expected based on random use of available habitats. Agricultural lands, intermediate deciduous forests, old field, and water were used in proportion to availability. Wooded pastures (agricultural) and recently logged areas (open woodland) provided foraging habitat. Many bats used multiple diurnal roosts; twenty-six roosts were found in 9 species of trees. Five bats, males and females, used the same roost tree for 2–3 consecutive days. Many roosts were near canopy openings; ten were in selective cut, clear-cut, and pastured woodlands with scattered trees and open canopies, and 5 were near or along logging roads or powerline corridors with open canopies. Eleven roosts were in forests with moderate to high canopy closure. Roosts were clumped near the cave (mean = 0.8 km; SD = 0.3). Roosts closer to the cave,, although limited in number, may provide an advantage during swarming. Prolonged wet, cold weather systems appear to be a part of the seasonal cycle that drives timing of autumn swarming.

We conducted a study of the diet of the federally endangered Indiana bat (Myotis sodalis) at an urban/rural interface near Indianapolis International Airport in summer 2004. We used two 1-m² quadrats covered with window screening to collect guano under a known roost tree. We then examined 20 fecal pellets/week until the bats abandoned the roost (i.e., 13 weeks). The most common orders of insects eaten were: Lepidoptera (35.3% volume, 84.6% frequency), Diptera (27.9%, 73.2%), Coleoptera (16.9%, 62.9%), and Hymenoptera (10.9%, 45.9%). Components of the diet at the ordinal level varied significantly over time. Despite the developed nature of the site, the diet consisted of the same components reported in earlier studies.

The objectives of this project were to: assess the presence of aquatic macrophyte species assemblages, associations, and/or communities; assess the distribution of Cabomba caroliniana (fanwort) and other macrophytes with water depth; and analyze the spatial distribution of fanwort and other macrophytes using a Geographical Information System (GIS). The study site was a shallow, eutrophic lake in North Reading, MA. Macrophytes were sampled along 36 transects located across the littoral zone. Ordination analysis showed some strong macrophyte associations and the presence of four partially distinct communities. However, the two most abundant species at the site, Cabomba and an aquatic moss (Drepanocladus sp.) had both limited associations with other species and were strongly segregated from one another. Our results show that spatial and distributional analyses can be coupled with macrophyte composition data to provide robust assessments of macrophyte species patterns. These techniques are especially valuable when assessing the extent and influence of non-native, invasive macrophyte species.