Document 3QoqzndorJBq5zknkBE3eBrJ6

Water quality in industrial areas: profile of a river The lower Hudson, like most tidal areas, must serve many needs, and its biological status is a direct measure of its ability to do so Ow /siri Me f.m TI he Hudson River drainage area, one of the major watersheds of east ern North America, encompasses about 12,400-14,500 square miles, and supports a human population of about 10.5 million. The flow in the south erly portion is controlled by a dam at Troy, about 155 miles north of the river mouth. The channel of the river can be traced well out into the Atlantic, and, at the northern limit of the tide at Troy, the river bottom is still four feet below sea level. The physical characteristics of the river bed indicate that it is a "drowned river." The lower Hudson is a major trans portation artery and, at the same time, a source of water for industrial and domestic purposes, an unsurpassed rec reational resource in an area of great natural beauty and important histor ical associations, and serves as a drain for industrial and domestic wastes. The economic, industrial, and recrea tional potential of the river can hardly be overemphasized, yet, regret tably, little is known about its hydrol ogy, biology, or chemistry, At a time when there is a need to predict the impact of projected developments, much basic data stili are unavailable or controversial. Part or all of the lower Hudson can be defined as estuary. The more seaward stretches are mesohaline (from two thirds to one third sea water), an intermediate zone is oligohaline (one third to one tenth sea water), and there is a final limnetic (or fresh water) stretch. The extent of these zones in the lower Hudson is closely dependent on fresh water runoff from the drai age area, and, consequently, the saltfront--or the in trusion of seawater--varies from year to year, and with the seasons. Hydrology The average annual fresh water in flow into the lower Hudson at Green Island has been estimated at between 12,000-23,000 cubic feet per second (c.f.s.). This flow is uneven, with spring maxima as high as 40,000 c.f.s. (as in April 1967), and summer min ima as low as 2000 c.f.s. The summer low flow period lasts from four to seven months each year. As the fresh water flow diminishes, the salt water front pushes upstream from its spring limit near Tappan Zee (30 miles from Battery Park, Manhattan), reaching Newburgh (59 miles), Pough keepsie (74 miles), or even Kingston (88 miles) in the summer and fall, depending on the annual rainfall. At any station on the river, the salinity increases progressively from May to November. There is generally a minor additional flow of fresh water before the cold temperatures of mid-winter reduce the flow. Although salinity is reduced somewhat (and the salt front pushed southwards), it remains rela tively high throughout the winter, until the spring thaw brings about a massive dilution in March or April. As seawater pushes up a river at flood tide, it tends to form a wedge of more dense saline water at the bottom of the river bed. Since the Hudson River is more than 100 feet deep in places, this saline water might be ex pected to remain near the bottom. In fact, only relatively slight differences have been seen between the surface and the bottom, indicating that the water gets fairly well mixed, at least north of the Tappan Zee. The northward motion of the tides at some periods apparently reverses the river flow; since the tidal flow is massive--approximately 300,000 c.f.s.--it dwarfs the summer fresh water flows. Upstream flows of 19, 000 c.f.s. have been measured at Gov ernor's Island, 5000 c.f.s. at Riverdale, and even 2100 c.f.s. at West Point. The Federal Water Pollution Control Administration's Hudson-Champlain project, using dye marking studies, showed virtually no flow during the summer of 1965, when dyes added to the river at different sites were fol lowed for 14 tidal cycles. At the head 26 Environmental Science A Technology DSW 033863 .1 t".l! the tl c\>. (U> II u in. In; t.O uri vt In Or fir ( Mr Uc luv .10 m !j c1 lv r n r a lx 3 t I c c ( I STLCOPCB4017825 feature Gwyneth Parry Howells and Theo. J. Kneipe Institute jor Environmental Medicine, New York, N.Y, Merrll Eisenbud Environmental Protection Administration oj New York, N.Y. s spring ) miles hatlan), Rough . ingslon id fall, ill. At salinity day to minor before -winter ini It front is relawinler, hout a pril. iver at ;dgc of bottom iudson lecp in be cxom. In eicnces surface tat the it least c tides ivcrscs I` flow 00,000 fresh of 19,t Goverdalc, Point. mp^K tudics, lg the ded to re folt head of the tidal influence at Troy, the tidal excursion was only three miles, bul the velocity of net movement of the dye mass downstream was a mile and a half for each tidal cycle, or about 20 miles in a week. At Kings ton and further south, while tidal excursions were greater, there was no net movement of the dye down stream. The overwhelming effect of the tidal flux appears to produce a seiche-like movement of the brackish water, but little effective exchange. The impli cation for pollution and eutrophica tion effects are clear. The large vol ume of water (150 miles long with an average cross section of 150,000 feet) behaves as a brackish Jake rocked north and south by the tide. The in flow is sufficient to exchange only 0,3 2% each day, assuming the simplest model of a single compartment, no evaporation or withdrawal, and no rain or additional inflow. The mean life of pollutants that remain in solu tion or suspension thus ranges from 40 days to more than 300 days, de pending on the flow. Effluents and nutrients discharged into this brackish lake, will, as in a true lake, be re circulated during dry summers be tween water, sediments, and biota. Only the high spring flows provide a flushing volume of water necessary to prevent an accumulation of pollutants and eventual eutrophication, T oo little is known about the phys ical hydrology of estuaries generally, and of the complex Hudson River system in particular. Without de tailed knowledge of the self-purifying capacity of a river or an estuary', we cannot make, a reasonable forecast of Die effects that will follow a polluting load. A British study of pollution in the River Thames demonstrated that the narrow parts of estuaries have a comparatively limited capacity to pur ify polluting material. The water flow ing to and fro is substantially the same water from one day to the next, and, at limes of low fresh water flow, pollutants may remain within the sys tem for several months, building up in concentration. The narrow tidal stretches of the Hudson, then, are most vulnerable to pollution, with a limited surface, area and mud-water interface available as either a source or a sink for pollutants. Hudson ecology The Laboratory for Environmental Studies, part of New York University Medical Center's Inslitute of Environ mental Medicine, has been studying aspects of Hudson River biology and chemistry since 1963. The study, financially supported in part by the New York State Health Department and the Consolidated Edison Co., de veloped initially from an interest in environmental radioactivity problems, and has broadened into a wider eco logical study of the effects of various pollutants on the biota. We are ac cumulating survey data from the river, and trying to relate our information to that from other studies, especially those of water flow and industrial use of the river. Those who have been actively en gaged in this study (aside from the authors) are A. Eerlmutter and H. Hirshficld of the biology department, and A. McCrone. of the geology de partment at the Washington Square STLCOPCB4017826 Campus of New York University, and Dale Bath at the Lanza Laboratory. Investigators pursued several lines of study: Considerable knowledge was ac quired about the abundance, distribu tion, and variety of animals and plants in the river, from microscopic forms to fish. Seasonal changes in the nutrient anions as well as trace cations were followed, A long, continuing study was made of levels of radioactivity--both natural and man-inade--in the water and biota. A study was made of levels of organo-chlorinc pesticides in the river water and mud, and their accumula tion in selected species of the biota. Present and future effects of heat additions to the river from industrial cooling and processes are being evalu ated. We are trying to sec how the ef fects of varying fresh water (low and tidal cycle influence the distribution of inorganic pollutants, nutrients, pes ticides, and heat, and how these af fect the biota of the river. In short, we are trying to predict the future of the river in terms of eutrophication, in the face of increasing industrial and domestic utilization. Nutrient loads The sparsely populated agricul tural Mohawk watershed, stocked with farm animals and supplied with fertilizers, provides significant nutri ent input. This is seen in the rela tively high nutrient levels of Mohawk river water (0.85 mg. nitrogen/1.) compared with other northeastern American rivers. About 17% of this could be attributed to natural runoff, and the remainder to artificial sources. The 10.5 million population of the Hudson watershed produces 61 mil lion kg. of nitrogen and 5.5 million kg. of phosphorus as domestic waste in a year, much of which ultimately will be carried seawards by the river. Other wastes such as domestic de tergents (contributing two thirds of total phosphate in one municipal dis charge), and wastes from meat and dairy industries, yeast production, and paper manufacture, also contribute to the nutrient load. Present municipal waste discharges north of Yonkers provide 1.6% of the spring volume of river flow, and 16% in the summer. At the Verrazano Narrows (Brooklyn), the proportions are much greater, because of the population density of the New York City area. The use of some rivers as sewage conduits has led to deoxygena tion and conditions impossible for fish life, especially when sewage disposal is coupled with other industrial uses. The nutrient content of the river water reflects its use. At Indian Point (43 miles from the Battery), the phos- Mesohatine zone, 1/3-2/3 seawater Distribution of common - i----------------- Oligohaline zone, 1/10-1/3 seawater Anetnonos, jellyfish fio mu IN. M. ,.< *n. till tic ph th; by the lut (S is M.*' CO lat cq pr ab Statue ot Liberty Battery Perk George Waihington Bridge Tappen Zee Bridge Newburgh Poughkeepsie STLCOPCB4017827 aste tdy ,ver. dc ; or dis and tion, ibutc irges f the 16% iZBDO lions the York rrs as genait fish sposal uses, river Point phos mon phorus content of the water ranges from 9.5-2.5 /ig.-atoms/l. and, at the southern tip of Manhattan, a maxi mum of 12 ^g.-atoms/1. was recorded, (Seawater has about 2 ^g.-atoms/l.) Most of the phosphorus (70%) is present as inorganic phosphate, avail able for immediate plant assimilation and growth, while the remainder is dissolved organic phosphorus or par ticulate material. In general, phos phorus in river water usually is higher than in lakes, but these vulucs arc high by any measure--2.8 ^g. atom/1. is the approximate upper limit of unpol luted water. Lake Washington (Seattle, Wash.), where eutrophication is slowly being reversed by a costly sewage diversion, has a phosphorus concentration of 7.5 ^g.-atoms/l. Kelchum deduced a theoretical re lationship that oxygen demand is equivalent to the oxygen supply from photosynthesis at concentrations of about 2 /ig.-aloms of phosphorus/1. At higher phosphorus concentrations, the net oxygen demand during dark ness will deplete the dissolved oxygen levels in the water. On this basis, we might expect that south of Albany, and around Manhattan, there will be net oxygen depiction. This has been shown to be true by monitoring stud ies of dissolved oxygen and biological oxygen demand levels. However, at many sites on the river, the dissolved oxygen level is adequate to maintain a healthy fauna in spite of the high phosphorus content. Nitrate nitrogen concentrations in the mid-Hudson range from 0.2 mg. to as much as 1 mg. N/l., and are somewhat related to the tidal in cursion. Inflowing water frpm the up per Mohawk watershed has a con centration of about 0.85 mg. N/l. These levels may be compared with values of 10 mg. total N/l. in the Thames River in England, and values around 1 mg, or less in relatively un polluted lakes. A seasonal fall in ni trate concentrations, such as that seen in the late spring of 1968 at Indian Point, could be a limiting factor in phytoplankton growth in this region, although many other factors may be implicated. Nitrates can act as an im portant reserve of oxygen, even with appreciable concentrations of dissolved oxygen, but, in anaerobic conditions, nitrogen compounds are reduced to nitrogen or even to ammonia. The nitrogen cycle is related to dilution, oxygen, and temperature, and compli cated by the efTccts of nitrogen fixa tion or denitrification by bacteria or plants. Preliminary data on sulfate levels indicate about 25 mg. S04/1. at Nyack, fairly closely related to salin ity. As with nitrate, sulfate can be reduced to sulfide by bacteria in an aerobic or near anaerobic conditions. The availability of these important anions--nitrate, phosphate and sul- species in the Hudson River Limnetic zone, fresh water Hydra Bosmlna Daphnla Gammarus ughkoopslc 1 Kingston Hudson Albany DSW 033866 STLCOPCB4017828 t f Protozoa Coclenteratcs ftotifers Worms Crustacea Molluscs Insccta Common invertebrates of the lower Hudson River Mesohaline zone Dinufiayellates , Olitjohaline zone Difiiugia Arcclla Ochromonas Polytomella Limnetic zone Volvox Synura Paramecium Amoebae Sea anemone (Sagartia) Jelly fish Ctcnophoies Hydra o/iyactis Occasional jelly fish Hydra oligact/s Tric.hocerca sp. Keralella cochlearis Philodina Polychaetc-s Polychaetns Harris crab (Rhithropanopeus) lllue crab (Callinectes) Prawn (Palaemonetes) Shrimp (Ciangon) Bosmina longirostris Barnacle larvae Copcpods: Microarthridion Cyclops bicuspedatus Acartia tonsa Gammarus fasciatus Prawns Shrimps Bosmina longirostris Barnacle larvae Copepods: Microarthridion Cyclops bicuspedatus Lurytemora hinindoides Ectinosoma eurticorne Tubifex sp. Aeofosoma Nematodes Gammarus fasciatus Crayfish (Orconectes) Bosmina longirostris Daplwia pulex Copepods: Microarthridion Cyclops bicuspedatus Diaptomus pallidus Snails (Physa) Clam (Mya) Oyster (Crassostrea) Conqcfift leucophaeata Sphaerium Ellipt/o complanatus None Chaoborus a/bipes Tendipes Chironornid larvae Dragon fly larvae Stone fly larvae. May fly larvae } fate--is important in a consideration f possible eutrophication of the lower udson. The present move to treat sewage so as to provide a liquid ef fluent may do little to reduce the nutrient levels of Hudson River water. In fact, it may worsen the present situation, since the treated efllucnt will provide nutrients in a readily avail able soluble form. Nitrate and phos phate levels in the Hudson are more than sufficient to develop algal blooms. Profuse blooms would result in a net oxygen depletion, with the subsequent reduction of nitrate and sulfate to noxious gases. In a flowing aquatic system, the interaction of nutrient concentrations and Water temperature may be of major importance in con trolling algal growth rates. If algal production exceeds the rate of removal by downstream flow and predation, nuisance blooms could result. Heat additions A further problem of growing im portance is the use of water for in dustrial cooling. At the present rate of increase of water use in U.S., about )% of the total fresh water runoff Tn the next 10 years will be required for cooling. Considering seasonal var iations, about half of total runoff will be required for two thirds of the year. In the highly developed north eastern states, there are a number of rivers whose total flow is utilized, sometimes more than once in the pas sage downstream. Excessive water use will build up the heat load of fresh waters and estuaries; fortunately, heat is not conserved and can be dissi pated to the atmosphere, provided the volume of water is adequate. Here is a situation where good management of water resources is essential to maintain water quality. The siting and design of power stations must be considered from the point of view of biological effects, so that overuse of the water resource is prevented. The difficulty lies in determining at what level of heat addition Ihe biological effects are significant. Long-term heat changes have been well documented for the Thames River, where heat released to the river rose from 555 raW in 1930 to about 3700 mW in 1950. The total volume of cooling water was approx imately 2000 c.f.s. with a summer minimum of only 260 c.f.s. Of the total heat load in 1950, 75% was contributed by fossil fuel power sta tions, 6% by industrial effluents, 9% by sewage effluents, 6%' T>y fresh water discharges, and 4% by bio chemical activity. The yearly average temperature in the river over these 20 years rose from about 53 F. to 30 EnHroomenUl Sdenc* St Tsehnoto*/ about 60 F. (an estimate corrected for changing meteorological condi tions). On the basis of the proportions of contributors above, three quarters of the 7 F. rise (or about 5.3 F.) is due to about 3000 mW of power. The biological effects of such a tem perature rise arc not known, but Ihe additional temperature in the Thames increased the oxygen deficit by about 4%. This effect is not large, and the estuary would have remained an aerobic even if its water had not been used for cooling. However, it was calculated that the reducing con ditions, together with the temperature, increased the evolution of hydrogen sulfide by 20%, Following the intro duction of strict legislation to control (he quality of industrial discharges other than heat, hitherto fishless zones of the metropolitan Thames once again support fish life, albeit of species tolerant of the low oxygen. The flow of the Hudson is about 15 times greater than that of the Thames. The thermal capacity of the four power stations on the river is only 3000 mW, but projected development within the next few years includes an additional 10,000 mW. While the flow of the Hudson is not, so inten sively utilized as the Thames, and ambient air temperatures in the two countries are not the same, the paral- OSW 033867 let i o( ' mug Blot 1 ill t perl Stall 30 > fish info beni rise poll' met. beer and abui resp line drav the Eve in vc Hof will Tutu O rath Hud the abut spec rotif arc The and phys s r Navi STLCOPCB4017829 "1 etc' nd, .ions rlers .) is iwcr, temt the anics iboul and i an- not tr, it conaturc, ropen inlioontro) larges zones again pecics out IS names. four s >P<^F icludcs He the Jnlen- s, and be two paral- Icl is interesting, indicating the sort of temperature change, if not the magnitude, we might expect. Biology of the Hudson The variety of plants and animals in the Hudson is known only im perfectly. A study by the New York State Conservation Department some 30 years ago gives a good account of fish and rooted vcgetalion, but little information about the plankton or benthos (bottom living fauna) of the river. To evaluate the effects of such pollutants as excessive nutrients, trace metals, pesticides, and heal, we have been inventorying the kinds of animals and plants in the river, their relative abundance, and their distribution with respect to salinity. With so little base line information, it is difficult to draw conclusions about changes in the biota that may have occurred, liven for fish studies, the methods of investigation have not been repealed. Hopefully, our present knowledge will be adequate to allow us to predict future changes in the river. Our studies indicate there are two rather distinct environments in the Hudson River--the main channel and (he shore. The main channel has abundant plankton, a rich variety of species of protozoa, diatoms, algae, rotifers, and the small Crustacea which are important as food for larval fish. The shore has a rather different fauna and flora, partly because of different physical conditions, but also perhaps because pollutants from shore-sited industry sweep along the shores be fore they are diluted by the main body of the river. In the oligohalinc stretch of the river, the dominant phytoplankter dur ing the spring and summer is the Melosira anrbigua, but, during the fall, this species gives way to others, At the same time, salinity rises with the summer seawater intrusion, allow ing survival of a more marine-type biota at this site. When the estuary water is diluted by early winter or spring rains, a return of Melosira is seen, together with a variety of other fresh water forms. At a more southerly station on the river, a similar microflora to that at Indian Point was found during the summer. The limnetic zone in the summer is characterized by other species of Melosira and by other fresh water species. At all stations along the river, a number of species are found which might be considered as indicators of eutrophication. None of these were found as blooms, but the biological potential for nuisance algal growths (eutrophic species and more than adequate nutrient levels) un doubtedly is there. The zooplankton characteristically is dominated by the microcrustacea, largely a flourishing copepod fauna. A number of crustaceans appear to be ubiquitous throughout many miles of the Hudson. Barnacle larvae arc com mon in the plankton of mcsohaline and oligohaline zones, derived from a benthic adult population extending to Peckskill. (Some of the copepod species show a transition with chang ing salinity.) An important zooplanktcr for fish nutrition, Mysis oculata, was found at Indian Point only in the fall of 1968. when salinity reached about 25% of the seawater levels. Anoihcr group common in ihe zoo plankton is the rotifers, sometimes frequent enough to be termed blooms, again with a succession of species in habiting different zones. The rotifer fauna appears to be 'rich and varied. ' - V' i * ,Ti; ' :-r ( -r .. ."'V nyf\-' . - J.-y-l:-----V.I ----- - /if- 033868 Navigational aid. Esopus Meadows Lighthouse illustrates transportation, recreation, and aesthetic value of Hudson River Volume 4, Number 1, January 1970 31 STLCOPCB4017830 II *** f t'. .:W 1 ; t1 r< * V*.t I# iK' tid /.!. <rlj r*' f rM >:r,' l ho An The protozoan fauna is also rich in species in all parts of the river, but we do not have quantitative assess ments of the relative dominance of species. Ciliates (25 genera) and flagellates (15 genera) are common, as nre shelled amoebae (15 genera), in shore collections. Of the larger in vertebrate inhabitants of the river bot tom and of the shores, we know little about relative abundance, but something about distribution. Larger Crustacea arc represented by the Harris crab and blue crab in the more seaward stretches of the estuary, and by shrimps and prawns in less saline water. Replacing these decapods in the limnetic zone arc crayfishes. The pres ence of the crabs upstream of Tappan Zee seems to depend on the seawater intrusion during the late summer. The apparent scarcity of crabs in very recent years may then not be due to pollution, but rather to freshening of the river after the drought years of 1964-66. Mollusks also show a salinity re lated distribution. One species of oyster has been found as far north as the Tappan Zee; in the fresh water, gas tropods are common. Insects are scarcely present in the more saline sampling can be used to indicate wa reaches, only the larval Choobonis and ter quality changes. Most of the fish Tenilipes extend into the oligohaline show little distribution related to sa zone. Other insect larvae are found in linity, since they are euryhaline, and the limnetic zone, but are restricted able to live in waters of a wide range to the shore, except for chironomids. of salinity. The fresh water variety of 'River mud provides habitat for worms. killifish is dominant in the upper The river has a large population reaches of the river, while (he euryha- of endemic fishes. Some 70 species iine type is more common further recorded in 1936 include a tremen south, and their distribution reflects the dous migrant population of diadromous seawater intrusion. It is difficult to fish, many of which migrate into the make valid comparison of the fish Hudson or its tributaries to spawn. fauna of the river now and in 1936, but The shore environment serves as a it is clear that the Hudson still presents nursery ground for the juvenile fish an environment rich in variety and who feed on the snails, shrimp, and quantity of fish, even though com insects available there. This popula mercial fishing in the river has se tion has been sampled at selected sta verely declined. tions along the river for the past five years by shore seining, and about 35 Radionuclides species have been recorded. The fish The lower Hudson River receives sampled by this technique are mostly direct industrial waste discharges, as in their first or second year, and well as material from the watershed some fish known to be present in area, and the levels of some waste the river--such as the hogchokcr and products in the river and its biota the sturgeons--have not been seen. are of interest. We followed radio The shore sampling thus does not nuclide and pesticide concentrations represent the true population, but in the water and mud and their ac only juvenile and small species which cumulation in the biota of the river. seek sheltered and shallow inshore The' radionuclides are derived from areas. However, the consistent annual three sources: 32 Environmental Science & Techiwlofy DSW 033869 m.j :tu n.t Ulv is vto M;to \v; act w.t pci nn f.v 1' .H h V \ tl n n n ir 1 n i i c ( STLCOPCB4017831 j wa if fish 10 6a- and range ety of upper Jryhaurthcr -ts the ult to e fish <6, but escnts y and com as se- eccivcs ges, as tcrshed ; rations >cir acNer. d from * Natural 'products, sucb <is radium and potassium-40. This group reflects the geological character of the water shed and the degree of salt water in trusion. Potassium-40 is the major con tributor of radioactivity in estuarine water and its biota. South of West Point, the mean potassium-40 con centration during the past five years was 22 picocuric per liter (pCi/).), less than 10% that of seawater, while, in the limnetic zone, it is only 1.5 pCi/1. Natural radium-226 and ra dium-228 derived from soils each con tribute only about one tenth of a pCi/1. * Fission products, derived front fallout from weapons testing. The nuclides derived from fallout are ce sium-137, strontium-90, cerium-144, and ruthenium-106. Levels of these nuclides in the water or biota are low, and together contribute only about 1 pCi/1. * Activation products released as a result of nuclear production. This group is the most interesting, even though levels are very low in water. Among the nuclides seen are cobalt60 and manganese-54. Although their levels are so low that accurate esti mates are difficult to make, their ac cumulation in plants or animals leads to the use of selected species as natural monitors. The situation is il lustrated best by manganese-54, which is found in river muds, especially downstream of the nuclear power station at Indian Point, where phys ical and chemical conditions of sea water promote the salting out of man ganese compounds. Doth stable manganese and its radio active analog are accumulated by some water plants, especially those in the genera Chora, Fotamogeton, Valinnerla, and Myriophyllum, which are found along the shores of the Hudson. Those plants growing closest to a re actor effluent site naturally show the highest levels of activity. The natural soluble manganese concentration in Hudson River water ranges from less than 0.5 to 12 ^g./l., and total manga nese (mostly particulate) about 1 mg./]. In Polamogeion crinpus, it is about 2.3 mg./g. wet weight, indicat ing a concentration factor of about 190,000, with regard to the soluble nuclide concentration in the water, or 2300 <0 the total nuclide concentration. The total radioactive manganese levels in river water during 1966-68 indicate concentration factors of about 10,000 (range 3000-18,000) for this and similar species, in the same order of Phytoplankton species in Hudson River at Indian Point too 80 a? 60, 40 mr/ij Has ''I'vi m 201 Apr. May June July Aug. Sept. e R Zo Oct. Nov. Characium mNitrschia Ulothrix LIPleurosigma Skeletonema E2JChaetoceros | | Fragilaria (ZZl Coscinodiscue F~~] Melosira [ 1 Anabaena [ | Asterionella [ j lhallassiothm magnitude as total manganese. Plants of other genera, or phytoplankton samples, showed much lower levels of manganese or manganese-54. Fish with a stable manganese con tent of only about 6 ^g./g. wet weight do not show appreciable- accumula tion of radioactive manganese, even though exposed to the same concen trations in the ambient water. Even if species of fish which are known consumers of plants are considered, there is no appreciable accumulation of manganese-54 observed. Hence, although these fish may ingest food high in manganese-54, low absorption by the gut probably limits its uptake in fish. Among invertebrates in the river, blue crabs did not show any manganese-54, and only traces of two fission products, cerium-144 and ce sium-137 (in 1964). Other crusta ceans--crayfish, prawns, and shrimp-- have similarly low concentrations. On the other hand, fresh water clams, which feed by filtering plankton and sediment from the water, showed a larger accumulation of radionuclides, including mangancse-54, though not so much as plants. Other filter feed ers--barnacles, oysters, etc.--were not sampled, but might be expected to have similar values. The relative ac cumulation from the two routes--di rect uptake from the aquatic environ ment and uptake from ingested food-- is not known. Pesticides OSW 033870 While the distribution of radionu clides in the river water, mud, and biota reflects the distribution of the stable elements, as well as chemical interactions and the physiology of the biota, the distribution of pesticide residues reflects more clearly accu mulation through trophic levels of the biota. Hudson River water con tains numerous pesticide residues of the chlorinated hydrocarbon type, but only during the spring runoff are con centrations as high as 0.25 jtg./l. At other limes of the year, the levels are too low for effective quanlilation, generally less than 0.010 /tg./l., but Volume 4, Number 1, January 1970 33 STLCOPCB4017832 the residues can be more readily ide;!^tided in biological samples. Like other major northeastern r:>ers, the Hudson River water appear* :> have little ddt, although its rr.<p.abolites ore present. Dicldrin si present in about the same levels of cotvccntrntion as the ddt metabolites. Thnpattern of occurrence is reflected sv the biota, where accumulations <A dicldrin and ddt metabolites arc sset., rather than ddt itself. The muds tak>r up pesticides from the water or reta..o them in settled sediments after thf spring runoff. Muds contain the pes ticides at 0.01-0.05 /rg./g. dry weight, generally several thousand tinrcei higher than the water. Plankton ir> the water, perhaps feeding on bom microforms and suspended particles, build up concentrations of pesticide of about 0.02-0.06 fig./g. wet weight (0.1-0.3 /ig./g. dry weight). This is about five to ten times higher than the sediments and about 20,000 times higher than water. Clams feeding on the plankton would be expecled to accumulate the residues to an even higher degree, but, in fact, pesticide concentrations in the fresh water clam arc of the same order, 0.03-0.07 ./rg./g. wet weight. 'arious fish species in the river have pesticide concentrations ranging from 0.05-0.8 pg./g. wet weight. Lxic.il birds, such as heron and killdecr, thought to be consuming fish or in vertebrates from the river, have 0.3 3 ng./g. wet weight on a whole body basis. The pesticide residues are par ticularly concentrated in fat, -Thus, the continuing concentration through the food chain results in relatively high pesticide concentrations at the top of the food chain even (hough the base levels in the water arc relatively undetectable. This has been ob served in other environments. Trace element concentrations in the river water show great variability with sampling station, state of the tide, and temporal differences which, perhaps, reflect intermittent discharge of effluents from industries. Gener ally, in the limnetic zone, levels of trace metals are much less than those permitted by state or federal drink ing water standards and do not ap pear to cause nuisance. In the more estuarine reaches of the river, high concentrations of iron, copper, and cadmium have been seen. Extensive studies would be required to locate the sources of such sporadic trace metal concentrations. Evaluation of potential biological cfTccts would re quire application of sophisticated mul tivariate analysis. Muds in the river may play an im portant role in the sequestration or regeneration of toxic material derived from pollutants, in addition to their role in the oxygen cycle. Our survey of radionuclides and pesticides has indicated that muds always are much higher in concentrations of these ma terials than the overlying water. There are other indications from gas chro matograph tracings that they are ac cumulators of diverse organic resi dues as well. Most mud samples from the lower river arc clay sills with about 5-6% of easily oxidi/.able humic material, 50% silt, and 20-45% clay. The cat ion exchange capacity of the muds is considerable, even in the brackish reaches where cations are readily available in the water. Consequently, most of the exchange sites on the muds arc occupied by hydrogen un der predominantly reducing condi tions. The niuds contain a substantial amount of manganese, (0.72 pg./g. wet) compared with the ambient water, (0.01 ^g./ml.). Hence, there is a sedimentary reservoir of manganese which could be available if reduc ing conditions prevail. Appreciable amounts of iron in the ferrous state also are present. Organic matter in the muds, oxidizuble by hydrogen peroxide, accounts for more than 65% of the cation exchange capacity. To gether with the unsaturated nature of the exchange sites, this indicates that, in relatively well oxygenated Manganese concentration in Hudson biota Radioactive manganese Stable manganese r i ) iv i > t \ I I xlO xlO 34 Environmental Science & Technology X100 ^ IL 1.6 1.2 0.8 0.4 pCi/g. xl00 1.0 2.0 mg-U. 3.0 co m m jE </> Q c< si* a M th C ct th tr fc P' in at ti< bt so P1 Sp hi P` ft di in PC al, th insc ha tht du ca of us of fee trot 1 viru Hui be the c.ij sev me hig nifi the pro tnu unV big rjs tjn Kcj rot 11>* It 4 STLCOPCB4017833 conditions, the muds may have con siderable capacity to absorb chemi cal pollutants, including radionuclides. More research is needed to evaluate the role of the muds in this capacity. Conclusions It is not difficult to predict an in creased use of the Hudson River for the disposal of sewage wastes, indus trial effluents, and cooling water, and for augmenting existing' water sup plies. At the same time, the burgeon ing population of the area has a need and a right to use the river for recrea tion. How can further development be controlled, so that the water re sources can be exploited, but still provide for that refreshment of the spirit so necessary for the urban in habitant? Changes that might be ex pected from increased use are: First, an increasing nutrient load from domestic sewage and some in dustrial processes. Second, an increasing heat load. Third, an increased demand for industrial and domestic water. Our studies have made clear that potential eutrophic nuisance species of algae are present in the river, and that the shores arc populated by animals indicative of sewage pollution. Vet, serious fouling and deoxygenation have so far been avoided for most of the river. From this it could be de duced that the present situation need cause no concern; however, examples of other eutrophic water bodies give us warning of the potential rapidity of changes, and should encourage ef fective sewage treatment and the con trol of nulricnt sources. Heat additions to the aquatic en vironment are r major concern. Jn the Hudson, the volume of tidal flow can be utilized lo disperse such heat; at the same time, it is clear that the capacity of the river as a heal sink is severely limited during the peak sum mer demand by a low net flow and high ambient air temperatures. If sig nificant overall temperature rise in the river were allowed, it is highly probable that the species composi tion of the fauna and flora would be unbalanced. This interacting with the high nutrient levels in the river could easily tip the balance between nui sance conditions and the relatively healthy biological situation seen to day. The effects of a temperature rise restricted to localized sites on the river have yet to be evaluated. There is a great need for more detailed hy drological and thermal studies of the river to evaluate the capacity of the Hudson to receive heat addition. There is also need for studies of spe cies endemic to the river to deter mine their response, singly and to gether, to changes in temperatures. The extraction of additional water for any purpose--pumped storage schemes, industrial use, or domestic use--is also of great importance, and is closely related to the other uScs of the river. Almost any increased wa ter extraction, except industrial cool ing intakes, will make a volume of water unavailable at least for limited periods or limited stretches of the river. The effects of this on the pres ent hydrological pattern in the river remain largely unknown. It seems probable, however, that the extent and duration of salt water intrusion up the river will increase. This will limit the sites for drinking water ex traction and reduce the capacity for exchange of effluent discharges with the ocean which depends largely on the net fresh water fiow. ` How can the situation be con trolled? We need more information about all aspects of the hydrology of the estuary, about the fauna and flora of the river and their response to ex isting and predicted conditions. We need strictly controlled use of the river for all purposes and at all lev els. And, finally, we need to know how to alleviate pollution problems when they have arisen and how to channel waste materials, including heat, lo olhcr outlets. ADDITIONAL READING W. T. Edmondson, "Water Quality Man agement and Lake Eutrophication: The Lake Washington Case," in "Water Resources Management and Public Policy," edited by T.H. Camp bell end R.O. Sylvester, University of Washington Press, 139-178 (1968). "Effects of Polluting Discharges on the Thames Estuary," Water Pollution Re search Technical Paper No. 11, De partment of Scientific and Industrial Research, Her Majesty's Stationery Office. London (1964). B.M. Ketchum, "The Flushing of Tidal Estuaries," Sewage Ind, Wastes 23, 198-209 (1951). G.G. Polikarpov, "Radioecology of Aqua tic Organisms. Relnhold, New York (1966). D.W. Pritchard, "What is an Estuary: Physical Viewpoint," in "Estuaries," edited by G>k Lauff, American As sociation for the Advancement of Science, 3-5 (1967). U.S. Department of Health, Education, and Welfare, "Report on Pollution of the Hudson River and its Tributaries," U.S. Government Printing Office, Washington, D.C. (Sept. 1965). Gwyneth 'Parry Howells is senior re search scientist and director of Hudson River ecology studies. New York Uni versity Medical Center Institute of En- , vironnicnlal Medicine, a position she has held since 1967. Previously (1962~67), she was senior scientist. Medical Research Council, London. Dr. Howells received her B.Sc. (1946) and M.Sc. (1948) from the University of New Zealand, and her Ph.D. (1953) from Cambridge University (England). Mcrrll Eiscnbud is administrator of the Environmental Protection Administra tion of New York City, a position he has held since 1968. Previously (1959), he was professor of environ mental medicine and director of the laboratory for environmental studies, NYU Medical Center Institute of En vironmental Medicine. He received his B.S. from New York University (1936), and D.Sc. from Eairlcigh Dick inson (1960). Theo. J. Kucip is acting director of the laboratory for environmental studies, NYU Medical Center Institute for Environmental Medicine, a posi tion he has held since 1968. Prior to joining the institute (1967), he tvnr with Mallinckrodt Chemical Works (1954 63). He received his B.S. from the University of Minnesota (1950), and his M.S. (1952) and Ph.D. (1954) from the University of Illinois. OSW 033872 Volume 4, Number Jammiy 1910 3S STLCOPCB4017834