Anne Spacie

Uptake, depuration, and biotransformation of anthracene and benzo[a]pyrene in bluegill sunfish

Bluegills (Lepomis macrochirus Raf.) were exposed to [14C]anthracene or [14C]benzo[a]pyrene (B[a]P) in water. Rates of uptake and biotransformation within the fish were followed by 14C counting and thin-layer and liquid chromatography. The initial uptake-rate coefficient for anthracene (KU = 36 hr-1) was found to be independent of exposure concentration. The presence of dissolved humics did not affect anthracene uptake but did reduce the B[a]P uptake rate significantly. Biotransformation of the anthracene was constant at 0.22 nmol/g/hr, with approximately 92% of the residue unmetabolized at 4 hr. Uptake of B[a]P was linear (KU = 49 hr-1), although biotransformation increased from 0.044 to 0.088 nmol/g/hr between 1 and 2 hr of exposure. Only 11% of the B[a]P 14C activity at 4 hr represented the parent compound. Although 6% of the anthracene was found in liver and gall bladder, 25% of the B[a]P was distributed in the two organs. Depuration rates were first order and yielded half-lives of 17 hr for anthracene and 67 hr for B[a]P. The estimated bioconcentration factors (BCF) for anthracene and B[a]P in whole fish (KU/KD) were 900 and 4900, respectively, for total 14C activity, but only 675 and 490 for parent material. These BCFs were considerably lower than those predicted from the octanol-water partition coefficients because of biotransformation.

Changes in Fish Assemblage Structure Upstream of Impoundments within the Upper Wabash River Basin, Indiana

Abstract The effects of dams and impoundments on downstream fish assemblages have been well documented, but changes in fish assemblages in upstream tributaries have received little attention. We compared changes in abundance and composition in fish assemblages in streams fragmented by impoundments with those found in nearby unfragmented streams by sampling fish, in-stream habitat, physicochemical factors, and drainage features in 22 agriculturally dominated streams during the summers of 2002 and 2003. Eleven sampling sites were tributaries upstream of impoundments, while 11 were tributaries of free-flowing rivers. We tested the hypothesis that fish assemblages upstream of impoundments would differ from those found in streams without impoundments. Using multiple regression and canonical correspondence analysis, we partitioned the variation in species distributions into that explained by in-stream habitat, reach-level factors, drainage features, and temporal variation. Spatial patterns of species distributi...

Differential Use of Stream Habitat by Spawning Catostomids

Spawning patterns of suckers (Catostomidae) in Deer Creek, Indiana, revealed differential use by species and age-size groups. In spring, white suckers (Catostomus commersoni) dominated headwaters, while redhorse (Moxostoma spp.) were more abundant downstream. Shorthead redhorse (M. macrolepidotum) were present only in main stem Deer Creek during spawning. Spawning groups of golden redhorse (M. erythrurum) and black redhorse (M. duquesnei) near the mouth of Deer Creek were significantly older and larger than those upstream in a first-order tributary. Spawning was not observed until water temperatures stayed above or near 10 C and until water levels were 20-60 cm deep over spawning shoals. Golden redhorse, shorthead redhorse and northern hog sucker (Hypentelium nigricans) spawned over medium gravel in riffles 30-60 cm deep with velocities of 0.4-0.9 m/sec. White sucker spawned over medium gravel at depths of 20-25 cm where velocity ranged from 0.50-0.59 m/sec. Creek chubsucker (Erimyzon oblongus) selected fine gravel in areas 50-75 cm deep having much slower velocity (0.10-0.24 m/sec). INTRODUCTION River tributaries serve as spawning and nursery areas for suckers (Catostomidae), but the effect of tributary spawning on maintaining river populations downstream is just beginning to be investigated. Previous reports (Thompson and Hunt, 1930; Trautman, 1957; Bowman, 1970; Larimore and Smith, 1963; Karr, 1975; Burr and Morris, 1977; Smith, 1977; Lake and Morrison, 1977) indicate that catostomids inhabiting rivers ascend smaller streams for spring spawning. The extent of upstream movements by adults and the degree to which resident and migrant suckers compete for stream spawning sites are unclear. Lack of specific information on the seasonal use of river tributaries hampers management efforts and an understanding of the potential impact of stream alteration on catostomid populations. Studies on catostomid spawning have shown some interspecific differences in the use of river tributaries. Black redhorse (Moxostoma duquesnei) and golden redhorse (M. erythrurum) in the streams and smaller rivers of Missouri and Ohio apparently move short distances for spawning (Bowman, 1970; Smith, 1977). Meyer (1962) found no evidence for the movement of golden redhorse, shorthead redhorse (M. macrolepidotum) or silver redhorse (M. anisurum) adults into a tributary of the Des Moines River, Iowa, during the spawning season. However, the abundance of adult silver redhorse and quillback (Carpiodes cyprinus) in a tributary of the Hocking River, Ohio, increased during spring, suggesting upstream movement into the tributary for spawning (Smith, 1977). Some specific measurements of spawning site characteristics for catostomids have been reported in recent literature. Black redhorse in Missouri spawn on riffles of rubble and gravel in 15-60 cm of water (Bowman, 1970). Spotted suckers spawn over course rubble in riffles 0.3-0.5 m deep with flow rates of 1.4 m3/sec and surface velocities of 1 Journal Paper no. 9585, Purdue Agricultural Experiment Station. 2 Present address: 120 Riverglade, Amherst, MA 01002.

Acute Phototoxicity of Harbor and Tributary Sediments from Lower Lake Michigan

Abstract The phototoxicity of PAHs, together with their accumulation in sediments, suggest that dredging and other disturbances may pose a presently unrecognized environmental hazard. To test this, sediments contaminated with PAHs were collected from sites in the Grand Calumet River, the Indiana Harbor Canal, and Waukegan Harbor. The phototoxicity of liquid-phase elutriates was tested using Daphnia magna . Phototoxicity was found in Grand Calumet River and Indiana Harbor elutriates, both in sunlight and 354 nm near-uv. None of the elutriates was toxic in the absence of light. These results reveal an important and previously unsuspected hazard to shallow water environments near dredging sites, and describe simple methods to detect phototoxicity which will be of value in the establishment of sediment quality criteria.

Space as a limiting resource in freshwater systems: competition between zebra mussels (Dreissena polymorpha) and freshwater sponges (Porifera)

Species interactions between two types of sessile benthic invertebrates, the zebra mussel (Dreissena polymorpha) and freshwater sponges (Porifera), were evaluated in Michigan City IN Harbor in southern Lake Michigan during 1996. The study objective was to define whether competition plays a role in structuring benthic communities using experimental techniques commonly employed in marine systems. Sponges were uninhibited by zebra mussel presence and overgrew zebra mussel shells on hard vertical substrata. In contrast, zebra mussels did not overgrow sponge colonies, but did show an ability to re-capture hard substrata if relinquished by the sponge. The negative affect of sponges on zebra mussels through overgrowth and recruitment suggests interactions that could eventually displace zebra mussels from these benthic communities. However, seasonal reduction of sponge biomass from autumn through winter appears to allow the zebra mussel a periodic respite from overgrowth, preventing exclusion of zebra mussels from the community and allowing these two taxa to co-exist.

Role of Electrofishing in Assessing Environmental Quality of the Wabash River

The fish community of the middle Wabash River has been studied since 1973 from the standpoint of its capacity for measuring the biological impact of various kinds of point influences, such as thermal, municipal, and industrial effluents. Of particular interest has been the potential value of various community parameters as indicators of environmental quality, since individual species populations tend to vary markedly from year to year. The primary sampling method consisted of repeated direct-current electrofishing through a series of 0.5-km-long zones located strategically throughout 274 km (170 miles) of river, divided into twelve reaches. The use of cluster analysis and community indexes, including a composite index, has been of value in isolating problem areas prior to the development of lethal environmental conditions and in gaging the degree of environmental benefit resulting from improved waste treatment.

The Effects of Sponge (Porifera) Biofouling on Zebra Mussel (Dreissena polymorpha) Fitness: Reduction of Glycogen, Tissue Loss, and Mortality

ABSTRACT The effects of freshwater sponge (Porifera) overgrowth on the fitness of adult zebra mussels (Dreissena polymorpha) were examined in East Chicago and Michigan City, Indiana harbors in southern Lake Michigan. There was significant reduction in glycogen content of sponge-covered zebra mussel soft tissue wet weight (mean=2.6%) when compared to the non sponge-covered population (mean=3.9%). Similarly, the soft tissue wet weight of sponge-covered zebra mussels (15 to 25 mm size class) was lower when compared to non-covered mussels. A comparison of the live:dead ratios of zebra mussels in both populations showed overgrowth by sponges had a significant lethal effect. These data suggest that the epibiont growth of freshwater sponges on adult zebra mussel shells negatively impacts the growth and survivability of zebra mussels.

Evidence of recruitment inhibition of zebra mussels (Dreissena polymorpha) by a freshwater bryozoan (Lophopodella carteri)

Competitive interactions involving macrofouling organisms were virtually unknown in North American freshwater systems prior to the introduction of the Eurasian zebra mussel Dreissena polymorpha. In southern Lake Michigan, the zebra mussel co-occurs on solid surfaces with an exotic bryozoan, Lophopodella carteri. Previously unreported from Lake Michigan, L. carteri was found attached to the shells of adult zebra mussels that were encrusting pier posts (depth 2-4 m) in the Michigan City, Indiana, harbor. This epizoic growth was often so prolific that entire patches of mussels were obscured by gelatinous colonies of L. carteri, thereby reducing shell surface area available to settling mussel larvae. A 4 to 5× difference in densities of newly settled mussels on mussel groups not covered by L. carteri compared to covered groups indicated that recruitment of mussel larvae was inhibited by the presence of bryozoan colonies. Although dense colonies of bryozoans, such as L. carteri at Michigan City, may not be widespread in the Great Lakes, locally dense populations may alter zebra mussel demographics by covering preferred attachment space.

Toxicity of inorganic selenium to the green alga Selenastrum capricornutum printz

Abstract The selenate (VI) and selenite (IV) forms of selenium were found to be acutely toxic to the freshwater green alga Selenastrum capricornutum Printz. The concentrations causing 50% growth inhibition (EC50) in 24 hr were 61.5 mg Se/l for selenate and 143 mg Se/l for selenite. Subsequent EC50 values for selenite were; 100 mg Se/l at 2 days; 96 mg Se/l at 4 days; and 65 mg Se/l at 6 days. Selenate was more toxic, producing 88% growth inhibition in 6 days at 40 mg Se/l compared to 18% for selenite at the same concentration. The relationship between growth inhibition and selenium concentration was found to be linear over the range of concentrations tested for both the selenate and selenite forms.

An Association between Freshwater Sponges and the Zebra Mussel in a Southern Lake Michigan Harbor

ABSTRACT Freshwater sponges (Spongillidae) were evaluated in a southern Lake Michigan harbor to determine whether preferences existed for attachment sites. Sponges were enumerated that were growing epifaunally on zebra mussel shells and directly on the associated iron revetment wall surrounding a portion of the harbor. Adult colonies of sponges were non-randomly distributed and found in close association with zebra mussel shells. The mechanism for this biotic interaction is unknown. However, this is another example of benthic restructuring of native fauna precipitated by the non-indigenous zebra mussel.