Author Institution: Center for Lake Erie Area Research, Ohio State Universit

Herdendorf, Charles E.

The Ohio Journal of Science

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Copyright © 1978 Ohio Acad. Sci. 0030-0950/78/0004-0229$! .50/0ENVIRONMENTAL IMPACT ASSESSMENT: AN AQUATICBIOLOGIST'S POINT OF VIEW1CHARLES E. HERDENDORF, Center for Lake Erie Area Research, Ohio State University.Columbus, OH 43210OHIO J. SCI. 78(4): 229, 1978In planning for water-use managementor activities in coastal or offshore areas,it is necessary to identify, through im-pact assessment, the ecological hazardsassociated with specific types of tuiliza-tions. It is the role of the aquatic biolo-gist to predict any adverse effects of theproposed action. The U.S. Atomic En-ergy Commission has defined adverse ef-fects to the ecosystem as follows:"Effects arc considered adverse if environ-mental change or stress causes some bioticpopulation or nonviable resource to be lesssafe, less healthy, less abundant, less pro-ductive, less aesthetically or culturallypleasing, as applicable; or if the change orstress reduces the diversity and variety ofindividual choice, the standard of living orthe extent of sharing of life's amenities; orif the change or stress tends to lower thequality of renewable resources or to im-pair the recycling of deplctable resources."A balanced impact assessment includesnot only adverse impacts but also anevaluation of positive ecological effectsand the determination of their impact onhuman needs. However, in practiceenvironmental impact studies have notnecessarily provided this type of infor-mation or disclosure. In November1973, Raymond L. St. Ores of the En-vironmental Review Branch, EcologicalServices Division of the U.S. Fish andWildlife Service presented a paper "Eco-logical Concepts in the Impact State-ment" at a seminar on EnvironmentalImpact Statements at Ohio State Uni-versity. He made two rather startlingstatements based on over 2,000 environ-mental impact statements that he hadreviewed in 314 years:"I have never seen an environmental state-ment, either draft or final, that is adequate1Manuscript received January 19, 1977 and inrevised form May 25, 1977 (#77-2).in the ecological sense, nor do I ever expectto see one.""The weakest part of environmental im-pact statements is that concerned withecology and it will probably always be so."What can the aquatic biologist do toimprove this situation? To meet thechallenge posed by Ur. St. Ores, OhioState University's Center for Lake ErieArea Research (CLEAR) undertook anassessment project which considered theenvironmental impact of continued min-eral extraction from Maumee River andMaumee Bay of Lake Erie. CLEARserves the University as a focal pointfor action directed toward solutions ofscientific and engineering problems of thelake and it is equally involved withsocietal and economic conditions of theadjacent coastal zone. The Center co-ordinates sponsored research in severalmajor areas of man's concern, contem-porary examples of which are: food re-sources from the lake, impact of energydevelopment, coastal zone managementand erosion control, pollution and eutro-phication, and mineral resources fromthe lake.The Maumee River estuary and Mau-mee Bay have distinct but interactingecosystems. Taken together they repre-sent a complex environmental unit thatis only now beginning to be understood.In recent years several federal, state andlocal agencies and institutions have takenan interest in the environmental con-sequences of proposed actions in thelower river and bay. The results ofthese studies provided a foundation uponwhich the proposed investigations andsubsequent assessment could be built.The assessment was of particular interestto clear because it provided an oppor-tunity to bring together informationfrom many other investigations in an at-229230 CHARLES E. HERDENDORF Vol. 78tempt to develop a coherent discussion tential environmental degradation whichof the Maumee River/Bay ecosystems. could occur.Equally as challenging was the problem A lengthy series of field and laboratoryof assessing the extraction of an important procedures were designed and conductedmineral commodity in terms of the po- to assess the impact of commercial dredg-FIGURE 1. Location of individual stations in reference to designated dredging areas in Maumee Bay.Ohio J. Sci. EIA-AQUATIC BIOLOGIST'S VIEW 231ing in designated areas within MaumeeBay and the Maumee River estuary byWhite Brothers Sand, Inc. A total of58 separate sites were selected as en-vironmental monitoring stations. Thelocations of individual stations werechosen in reference to designated dredg-ing areas, the proximity of active dredg-ing zones or as control sites separatefrom dredging areas (fig. 1). Three dis-tinct types of environmental studies wereconducted: sedmient, water quality, andbiological monitoring.Quarterly sediment samples were testedfor 20 parameters to determine thequanities of potential pollutants cur-rently locked in the sediments of thedesignated dredging areas. These an-alyses served to indicate the recentgeological history and economic impor-tance of the deposit through determina-tion of sediment particle size. The rolethese deposits may play in depleting thedissolved oxygen in the overlying watercolumn was another significant param-eter considered in this portion of thestudy.Prior to the initiation of commercialdredging (April 1975), an extensive seriesof water quality and biological monitor-ing samples were collected (March 1975)and analyzed at sample sites throughoutthe study area. Twenty field and lab-oratory determinations were made onsamples from each of the stations toestablish background readings for a broadspectrum of water quality and biologicalparameters during a period when activecommercial dredging was in abeyance.The same series of determinations wasmade bi-monthly during the dredgingseason to measure seasonal changes inoverall quality of the water mass and thepossible effects of dredging.Monthly replicate plankton and ben-thos samples were taken at 8 stations(at the time of collection water qualitydeterminations also were made) to quan-titatively determine and compare the den-sity of fauna in the water column and sub-strate of actively dredged and adjacentareas. A tri-weekly sampling programwas designed to collect and quantitativelydetermine the density of larval fish in theMaumee River estuary and MaumeeBay to allow little overlap of the sizeclass being sampled. Sites were selectedin Maumee Bay and the Maumee Riverestuary to assess the bay and the estuaryas fish spawning and nursery areas. Thedesign allowed for comparisons of the re-lative importance of the actively dredgedand adjacent areas in supporting the earlygrowth stages.A bi-weekly sampling program wasdesigned to sample the diversity andnumbers of larger fish at 2 stations eachin the Maumee River estuary and Mau-mee Bay dredging areas and 2 separatestations intermediate along the reach ofthe estuary between the two areas wereselected. The purpose of this portionof the study was to determine the relativenumbers, diversity, and apparent changesin numbers and composition of the fishpopulations in these areas and to assessthe impact of commercial dredging onthese factors.To assess the direct impact of thedredging activities, two 5-day periods ofintensive sediment and water qualitystudies were planned. Extensive fieldand laboratory determinations for sedi-ment and water quality parameters wereconducted in September and October1975 and a series of monitoring stationsseparated in space and time were designedto sample sediment and water in the nearvicinity before, during and after activedredging. During active dredging, sedi-ment samples were taken in the freshdredge cut.A second series of sampling sites wasdesigned to monitor a spectrum of param-eters along a 4 mile (6.4 km) reach of theestuary to bracket the designated dredg-ing areas by one mile, to bracket eachoperating dredge at distances rangingbetween 1200 and 2000 feet (370-600 m),and to include the maximum intensity ofthe effluent plume of each dredge. Thesesites were sampled in September andOctober. The determinations made dur-ing these studies were similar to thosebaseline series for water quality in Marchand the quarterly sediment series. Inaddition to these field studies, certainother assessment topics were investigated(see table 1).Continued sand and gravel productionwould be of economic benefit to theToledo metropolitan area. Short-term232 CHARLES E. HERDENDORF Vol. 78TABLE 1Assessment TopicsMaumee River and Bay ProjectI. PROJECT DESCRIPTIONa. Locationb. Purpose of Projectc. Current Operationsd. Future OperationsII. ENVIRONMENTAL SETTINGa. Natural Environmental Setting1. GeologyTopographyBedrock GeologyMineral ResourcesSand and Gravel Deposits2. HydrologyClimateMaumee River BasinRiver Flow CharacteristicsEstuary CharacteristicsBay Characteristics3. Water QualityPrevious InvestigationsWater and Sediment QualityStudy4. Biological ElementsPrevious InvestigationsBiological Monitoring StudyPhytoplankton and HigherAquatic PlantsZooplanktonBenthosIchthyoplanktonFishWaterfowl1). Man-Made Environmental Setting1. HistoryHistory of RegionHistory of NavigationDredgingHistory of CommercialDredging and Litigation2. Land Use Zoning3. Existing Water Uses4. Socio-EconomicsPopulation TrendsSocial CharacteristicsSand and Gravel Resources5. AestheticsPanoramic AspectsSensory FactorsIII. RELATIONSHIP OF PROPOSEDACTION TO MAUMEE RIVERESTUARY AND MAUMEE BAYUSE PLANSa. Maumee River Estuary and Mau-mee Bay Use Plans, Policies andControlsb. Recreational NeedsIV. ENVIRONMENTAL IMPACT OFPROPOSED ACTIONa. Hydrologic Impact1. Estuary ImpactSlope FailureIsland ConfigurationCross-sectional Area andRiver VelocityNavigational Hazards2. Bay ImpactWave Impactb. Water Quality Impact1. Previous Investigations2. Water Quality Impact StudyStandardsMaumee River EstuaryMaumee Bayc. Biological Impact1. Plankton2. Benthos3. Ichthyoplankton4. Fish5. Waterfowl6. Ecosystemd. Socio-Economic Impact1. Recreational Use ImpactMaumee River EstuaryMaumee Bay2. Other Water Uses3. Employment4. Sand and Gravel IndustryCompany RankingsContinuation of PresentOperatione. Historical and ArchaeologicalImpactf. Aesthetics1. Panoramic Aspects2. Visual Impact3. Noise Impact4. Air Ouality ImpactV. ADVERSE ENVIRONMENTAL EF-FECTS WHICH CANNOT BEAVOIDED SHOULD THE PRO-JECT BE IMPLEMENTEDVI. ALTERNATIVES TO THE PRO-POSED ACTIONa. Limit Dredging to DesignatedRiver Areasb. Limit Dredging to Designated BayAreasc. Expand River Dredgingd. Expand Bay Dredginge. No ActionVII. RELATIONSHIP BETWEEN LO-CAL SHORT-TERM USES OFMAN'S ENVIRONMENT ANDMAINTENANCE AND ENHANCE-MENT OF LONG-TERM PRO-DUCTIVITYa. Short-Term Effectsb. Maintenance and Enhancement ofLong-Term ProductivityVIII. IRREVERSIBLE AND IRRETRIEV-ABLE COMMITMENTS OF RE-SOURCES WHICH WOULD BEMADE SHOULD THE PROPOSEDACTION BE IMPLEMENTEDOhio J. Sci. EIA-AOUATIC BIOLOGIST'S VIEW 233negative effects, however, would includelimited hydraulic and water quality im-pacts, minor noise and visual impacts,and the reduction of benthic and plank-tonic life forms. The long-term adverseimpact would be slight. The scope ofthe proposed action is so limited in rela-tion to the magnitude of the river andbay ecosystems that a negligible environ-mental impact is anticipated.Dredging would increase the depths inboth the river and the bay. As a result,river velocities would decrease, particu-larly during periods of high runoff andfloods, causing the sedimentation of siltin the dredged excavations. In the bay,waves generated by intense storms wouldbreak closer to the shore if the entiresubmerged portion of Cedar Point spitwere to be removed. This would not re-sult in increased wave energy or erosionat the shore but might cause increasedscour 1000 to 2000 feet (300-600 m)offshore.There would be a temporary increasein turbidity and soluble constituents ofthe sediments in the water column ad-jacent to active dredges. The increasedload of suspended solids would reducelight penetration and thus reduce thedepth of photosynthetic activity byplanktonic forms. Planktonic organisms,including larval fish, would be lost ifthey were entrained in the service waterof the dredges. Likewise, benthic formswould be eliminated within the excava-tions.Aesthetically, because dredges are in-dustrial facilities not designed to bepicturesque, there would be some un-avoidable impact. Also, dredges wouldcause some navigational hindrance topleasure craft operating in the estuary.PlanktonDredging activities would reduce thetotal numbers of phytoplankton and zoo-plankton in the immediate vicinity of theoperations. This reduction in numbersis a result of the cellular disruption ofphytoplankton and the mortality of zoo-plankton caught in the wash water usedto process the dredged material. In ad-dition, the increased turbidity in theimmediate vicinity of the dredges reducesthe photosynthetic zone and, hence, themultiplication of phytoplankton. Atpeak population levels, 96% of the phy-toplankton enumerated was Aphanizo-menon sp., a blue-green alga uiversallyconsidered a nuisance species. Algal andzooplankton populations characteristic-ally exhibit periodic population changes.Therefore, the greatest number of indi-viduals of a given species would be de-stroyed during periods when the greatestnumbers were present in the water col-umn. The quantity of plankton whichsurvives the wash process is not knownbut is suspected to be low.BenthosDredging activities completely elimi-nate the macroinvertebrate populationsin the area being excavated. Sandy sub-strates typically exhibit a fauna of limitednumbers and diversity. Collections takenduring this study from the Maumee Riverestuary and Maumee Bay revealed afauna consisting largely of tubificidworms and midge larvae. These pollu-tion tolerant organisms are not highlyvalued. The stationary dredges operatein a limited area for lengthy periods. Thesweeper dredges operate primarily inpreviously dredged excavations. Thesurficial sediments are disrupted in re-latively narrow zones without wholesaledisruption of benthic habitat in the desig-nated dredging areas. It is estimatedthat recolonization of the excavations oc-curs within a year or less of dredging.The impact on macrobenthic populationsis extensive in the short term and minimalin the long run.I chthyo planktonDredging activities reduce ichthyo-plankton numbers in the same way plank-ton numbers are reduced. Larval fishcaught in the wash water processing ofdredged materials are lost. Most fishlarvae live a planktonic existence forseveral weeks post-hatching. It is onlyduring this period when larvae are un-able to freely move in the water columnthat they are vulnerable to the dredges.The principal larvae populations in theMaumee River estuary are, in order,gizzard shad and freshwater drum. Theprincipal larval populations in the shallowwater areas of Maumee Bay are, in234 CHARLES E. HERDENDORF Vol. 78order, gizzard shad and white bass.The Maumee River estuary was domi-nated by rough/forage and marginalvalue sport fish during the study period.The shallow water areas of Maumee Baywere dominated by forage fish and de-sirable Lake Erie sport fish. The num-bers of larvae captured in the designateddredging areas and in Lake Erie at themouth of the bay were considerably lowerthan those inshore in shallower water.A few specimens of larval mooneyewere taken from Maumee Bay duringthis study. The mooneye is listed by theOhio Division of Wildlife as an endan-gered species as authorized by the OhioRevised Code, Section 1531.25. Thespawning area for this species is uncer-tain. The density of these larvae in thedesignated dredging area is the lowestcomputed for any fish species capturedduring this study. This low densitymeans that the probability of dredgesdestroying a mooneye larva during dredg-ing operations in the bay is remote.The rapids zone of the Maumee Riverupstream of Perrysburg is considered bythe Division of Wildlife as a principalspawning area for walleyes. Adult wall-eyes spawn in this area in April, larvaehatch within 3 weeks and are carried tothe bay by currents in the elevated riverstage predominating during this periodof time. The personnel of the Divisionof Wildlife do not consider Maumee Baya walleye spawning area. No evidencegathered in this study indicates thatMaumee Bay is a significant walleyespawning area. The potential impact ofdredging on planktonic walleye larvae islessened by two factors: the high volumeof water in the estuary reduces the densityof larvae present, and many larvae willbe carried in the current through thenatural river channel, an area in whichthe dredges do not operate normally.During periods of elevated water levelsdue to spring runoff, the dredges arepositioned in areas where the currentshave the least effect.FishDredging activities have little directimpact on adult fish. The adults simplymove away from the disturbance. Com-mercial fishing, with the exception ofshore seining, is prohibited in MaumeeBay by the State of Ohio. There areno shore seining operations in MaumeeBay. Therefore, there will be no impactby the dredging activities on the com-mercial fisherman operating in the region.No positive correlation between larvalfish densities and subsequent adult popu-lations, with the possible exception ofyellow perch, has been demonstrated.Recruitment of young-of-the-year (Y-O-Y) fish of a number of species into theirrespective adult populations is not re-flected by their initial densities as Y-O-Y.WaterfowlWaterfowl, like adult fish, will respondto the disturbance caused by dredgingactivities by avoiding the immediate area.No waterfowl habitat would be destroyedEcosystemThe flora and fauna of the designateddredging areas are largely pollution tol-erant. The predominant fish species isthe gizzard shad, a primary consumer.Freshwater drum, a secondary consumer,are also common in all of the dredgingareas.Limited diversity has been demon-strated in the dredging and adjacentareas. Food chains are short. Second-ary and tertiary consumers are not com-mon and those captured during this studywere, for the most part, probable tran-sients rather than permanent residents.The overall impact of dredging activitiesin the aquatic ecosystem studied is minor.The ecosystem of the river/bay would notbe distinctly different if commercialdredging did not occur.One particular project has been singledout here to demonstrate the diverse rolethat an aquatic biologist must play in acomprehensive environmental impact as-sessment. I have attempted to showthat NEPA provides an excellent op-portunity for aquatic biologists to expandour knowledge of aquatic systems and tohave a direct input to the decision-making process which dictates the fateof these systems.

Environmental Impact Assessment: An Aquatic Biologist's Point of View

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Environmental Impact Assessment: An Aquatic Biologist's Point of View

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