Cooperative Research Re
Transcript of Cooperative Research Re
F O R E W O R D
T he monitoring of pollution in the sea is carried on throughout the world for a variety of purposes and by a wide range of local, national and international bodies. A substantial volume of data is accumulating on the distribution and amounts of certain contaminants, particularly with regard to residues in the flesh of fish and shellfish and the concentrations in water and sediments. A primary stimulus for such work is of course public health. However, concern for adverse effects on living marine resources and their habitats is also an im portant motive, and in this context the possibility of using a more direct approach by looking for effects on living organisms in the field is clearly attractive and has not received appropriate attention.
The International Council for the Exploration of the Sea (IC E S), following its initiatives in tissue and water monitoring, set up a small group to examine the feasibility of monitoring biological effects. The report of this group (ICES Cooperative Research R e port No. 75, 1978), emphasized the difficulties of identifying and measuring effects, pointing out tha t important effects were likely to operate at the population levels, where detection and assessment were least satisfactory because of natural variability. The report identified a num ber of possible approaches, and indicated areas where a start might be made in assembling relevant data, but it recognized that a wide interdisciplinary discussion of the topics was required, and proposed that a workshop be organized.
The workshop, arranged by ICES and sponsored in America by the National M arine Fisheries Service of the National Oceanic and Atmospheric Agency and the Environmental Protection Agency, was held from 26 February to 2 M arch 1979 a t Duke University M arine Laboratory, Beaufort, North Carolina. I t was organized by a small steering group and attended by 54 invited scientists from 11 countries. Papers, in most cases specially commissioned by the steering group, were prepared on a range of selected topics and circulated in advance. Each proposed participant was assigned to one of seven panels (Biochemistry, Physiology, Pathobiology, Behaviour, Ecology, Genetics and Bioassay) and panel chairmen were designated prior to the meeting so tha t early agreement could be reached on working arrangements.
T he first day of the meeting was devoted to a plenary session a t which theme lectures were delivered on each of the seven topics. The meeting thereafter broke up into panels to examine possible approaches to biological effects monitoring. At the end of the week the panel reports were presented and discussed in final plenary sessions.
The outcome of the workshop was an evaluation of a large num ber of procedures and a series of proposals for their application. This volume contains updated versions of the theme lectures, the contributed papers and the seven panel reports. The participants are listed in the Appendix.
A. D. M cIntyre J . B. Pearce
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R app. P.-v. R éun. Cons. int. Explor. M er, 179: 76-81. 1980.
A R E P O R T O N T H E C O A S T A L E N V I R O N M E N T A L A S S E S S M E N T S T A T I O N S
(C E A S ) P R O G R A M
Donald K. Phelps and Walter B. Galloway U.S. Environmental Protection Agency
Environmental Research Laboratory Narragansett, Rhode Island 02882, USA
A multi-purpose program, the Coastal Environmental Assessment Stations (CEAS), is described. The general goal of CEAS is to assess the relative condition of marine coastal systems through the use of the edible blue mussel (Mylilus edulis, Linnaeus) as a biological indicator. The present program has evolved from a num ber of years of research devoted to assessing the utility of various environmental stress indicators along a known gradient o f pollution from the highly stressed Providence River in upper N arra gansett Bay, R .I., to the relatively unstressed lower Bay. The resultant CEAS approach utilizes groups of mussels from a single population which are placed in cages along a gradient of pollution. This provides a field research platform upon which laboratory-generated response param eters are being tested and verified. Laboratory studies can then be conducted using those response param eters that have been verified as being meaningful through field exposure, and the field deployment itself can be used as a tool for environm ental assessment.
Early results indicated th a t after one m onth introduced Mytilus edulis accurately reflected the elevated tissue levels of heavy metals seen in the long-lived indigenous species Mercenaria mercenaria. Subsequent studies confirmed these results for heavy metals and also showed greatly elevated tissue levels of total petroleum hydrocarbons a t the stressed station as compared with the unstressed after two months of exposure. During 1977, physiological studies were carried out in addition to tissue residue analyses. Scope-for- growth (Widdows, 1978) measurements were made on Mytilus edulis collected along the transect, and results indicate a m arked reduction in scope for growth inverse to the levels of metals and hydrocarbons observed in tissues of organisms collected a t the same time. Additional response param eters are currently being evaluated.
IN T R O D U C T IO N
CEAS is an acronym for “Coastal Environmental Assessment Stations.” It is the name of a m ulti-purpose program, the general goal of which is to assess the relative environmental condition of marine coastal systems (including bays, estuaries and parts thereof) through the use of a biological indicator applied as a standard reference. The animal of choice is the edible blue mussel (M ytilus edulis, Linnaeus).
Degradation of the marine coastal environment is an insidious continuum that is only occasionally brought to light by such attention as was generated by the Kepone Incident in Chesapeake Bay, USA. U pper reaches of estuaries have historically attracted dense populations of man. Industry proliferates urban sprawl. Harbors, the focal point for development, in themselves become highly valued as a resource for easy waste disposal. However, the ease of such disposal is at public expense in the form of loss of fishery resources and at least some forms of recreational use of those same harbors. The CEAS program proposes to
measure the relative state of current conditions as well as to provide reference points against which future changes may be assessed.
T he use of Mytilus edulis as a biological monitor or sentinel organism has most recently been re-affirmed in the US by Mussel Watch (Goldberg et al., 1978). While Mussel W atch is an extensive monitoring activity, CEAS is an intensive effort to relate biological effect to tissue residues through selected field monitoring activities. An essential adjunct to the field aspect of CEAS, however, is a laboratory program which compares physiological response between field-exposed animals determined to have high and low tissue residue levels of such materials as heavy metals and total petroleum hydrocarbon.
H IS T O R Y
Narragansett Bay, Rhode Island, has the longest history of industrial impact of any area in the continental US. The Slater Mill was built in 1793 on the
A report on the coastal environm ental assessment station (CEAS) program 77
Blackstone River, a short distance above the upper reaches of the bay proper. Goldberg et al. (1977) were able to relate elevated levels of trace metals in sediments to the inception of that activity. Industrialization and urbanization of Providence developed rapidly. The bay has received effluent from textile mills, machine tool activities, jewelry and plating operations as well as hum an waste disposal systems since then. T race residues, both organic and inorganic, remain in the sediments (and flux into overlying bay waters) to this day in dubious tribute to that industrial history as well as in current testimony to the continuance of that activity.
There now exists in the bay a dynamic balance between current and historical input of anthropogenic materials. The upper reaches of the estuary, sediments especially, are heavily stressed for marine biota, while the lower bay is relatively clean. Subsequent discussion on CEAS and Mussel Watch will substantiate this point.
E V O L U T IO N O F CEAS C O N C E P T
T he Environmental Research Laboratory, N arra gansett, has been a generator of state-of-the-art bioassay methods for marine systems in the US since its establishment in 1963. Traditionally, bioassays are carried out in the laboratory dosing test animals at arbitrarily-arrived levels of toxicants and using a series of arbitrarily-chosen “response param eters” and endpoints to indicate sublethal physiological impact of stress. The data base created through this methodology is weak scientifically as well as being vulnerable legally when attempts are made to apply it in form of m anagement decisions affecting natural systems.
The CEAS concept was initially developed on the hypothesis stated as follows: “If laboratory bioassay results in fact have other than academic meaning, then those results should be observable (and in fact verifiable) in similar animals exposed under field conditions.” If positive results confirm the hypothesis, tissue residues may be compared between field- (multiple) and laboratory- (singular) exposed animals. Cause and effect relations may be established and verified in this manner between uptake of suspected toxicants under field exposure and related physiological impacts. In other instances, bioaccumulation, as evidenced by tissue residues from field-exposed animals, may generate candidate substances for subsequent laboratory bioassays.
If negative results are observed, the laboratory- derived physiological response parameters become suspect, and might reasonably be abandoned in favor of some more informative techniques. Levels of toxicants used in laboratory exposure systems may be deter
mined by monitoring water levels of the same toxicants to which field animals are naturally exposed.
In summary, a successful CEAS approach should provide a field research platform upon which laboratory-generated response parameters of physiological effects may be tested and verified. The laboratory phase of the CEAS approach would then use those response parameters that have been verified as being meaningful through field exposure to demonstrate under controlled conditions a cause and effect relationship between tissue residues and those response para meters.
M E T H O D S AND R E S U L T S
Initial CEAS studies made use of indigenous species to examine whether tissue residues reflected elevated levels found previously in sediment and water in the industrialized upper reaches of Narragansett Bay. R esults of this work are reported in Phelps et al. (1975) and Phelps and Myers (1977) and in fact verified the assumption that elevated metals observed in the water column and sediments owing to anthropogenic input were reflected in the total metal body burden of indigenous species. Farrington and Q uinn (1973) observed similar total petroleum hydrocarbon elevations in fauna collected along the same transect. Goldberg et al. (1977) were able to relate the vertical point in sedimentary history when elevated metal levels first appear to a date that corresponds to the birth of industrial activities on the upper reaches of the bay.
Phelps and Myers (1977) reported on the com parable utility of a variety of fauna as biological monitors for trace metal monitoring. Fauna were grouped according to feeding position in the physical environment: subsurface feeders (feeding below sediment- water interface comprised of non-select deposit feeders); interface feeders (feeding on sediment-water interface comprised of select deposit feeders); and water-column feeders (composed of filter feeders). Results indicated that for chromium, water-column feeders were the best monitor in that more animals had higher concentrations in tha t group than in the other two groups. For silver and zinc, the interface feeders were slightly better than the water-column feeders using the criteria defined above. T he subsurface feeders had significantly lower metal levels than the other two groups.
W ater-column feeders dominated by Mercenaria mercenaria were selected as the biological monitor. Collections were m ade along the transect shown in Figure 1. The num ber of metals was expanded to include chromium (C r), zinc (Z n), cadmium (C d), silver (Ag), copper (C u), lead (Pb), nickel (N i), cobalt (Co), manganese (M n), titanium (T i) , and
78 D onald K . Phelps and W alter B. Galloway
PROVIDENCE
MOUNT HOPE BAY
POPASQUASHPOINT
‘TRANSITION ZONE f
LOWERBAY
■SAKONNETRIVER
Figure 1. Area of study. CEAS transect stations 1-4 are indicated.
vanadium (V ). Results showed a break between high metal levels in tissues from animals collected at stations 1 and 2 and significantly lower levels a t stations 3 and 4. No gradually decreasing trend was noted. A time series was done on animals (Mercenaria mercenaria) collected from the vicinity of station 1. No seasonal shift in levels of tissue residue was observed. D epuration studies were conducted on M . mercenaria in which organisms collected from the same sites were analysed immediately upon collection and held for 30 days in clean laboratory flow-through sea water. Results indicated tha t three groups of metal/residue associations could be identified:
Group I: Cd, Cu, Ni, Pb, Ti. Mercenaria from “dirty” stations had significantly higher levels than those from “clean” stations a t the time of collection as well as at the end of 30 days.
Group I I : M n, Zn, V, Co. No differences between animals from “dirty” and “clean” areas at time of collection or after depuration.
Group I I I : Ag, Al. A pparent differences observed upon collection disappeared after depuration.
U ptake patterns of 65Zn, 65Zn plus stable Ag, and 65Zn plus stable Cu were compared between “dirty” and “clean” M . mercenaria (Phelps and Myers, 1977). Different patterns of uptake were observed suggesting tha t further physiological comparisons between the groups would be profitable. Scope-for-growth (Wid- dows, 1978) comparisons were carried out between these two groups of M . mercenaria (Alspach, personal communication 1978) bu t M . mercenaria proved not to be amenable to th a t approach.
A mass mortality of M . mercenaria, which occurred during the summer of 1973 decimating this “indigenous species of choice,” prompted the consideration of using an introduced species as the biological monitor of choice. T he use of animals from the same population would also overcome any question of genetic difference in interpreting differences in tissue residue levels between animals introduced along the transect.
The growing use and interest in M ytilus edulis as a biological monitor in addition to its history of productive use in physiological studies (Bayne, 1976) made it an obvious choice as another water-column feeder for use in the CEAS program. An exposure system was designed (Fig. 2) and caged M ytilus were distributed along the CEAS transect beginning in October 1976. Animals were all collected from the same population in the bay. This laid to rest concerns based on questions of genetic history. A laboratory population was also m aintained as a reference point.
For purposes of the CEAS program within N arra gansett Bay, the reference station is the unstressed station (station 4, Fig. 1 ) which forms the end of the transect. Station 1 is the most heavily stressed station of the four. Gradients of metals and hydrocarbons increase in the w ater column, sediment, and fauna as one progresses up the bay from station 4 to 1.
T he initial study (Phelps and Galloway, 1979) was intended to compare the efficacy of Mytilus, the introduced species, as a biological indicator with M ercenaria, the indigenous species. T he metals chosen for comparison were those concentrated but not depurated by stressed Mercenaria from station 1. Those metals were Cd, Cu, N i and Pb (Group I, Phelps and Myers, 1977). W ithin three weeks after distribution of M ytilus along the CEAS transect, the upper bay animals (station 2) had significantly higher levels of Ni, Cu, and Pb while levels of Cd remained unchanged (Fig. 3). These results established introduced Mytilus as a reasonable surrogate for indigenous Mercenaria and indicated tha t three weeks exposure was adequate.
A second study was initiated in 1977. M ytilus were distributed along the transect in May and were col-
A report on the coastal environm ental assessment station (CEAS) program 79
SURFACE
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FLOAT
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BASKETS
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Figure 2. Schematic of subsurface mussel station.
lected a t monthly intervals through December. Dissolved and particulate levels of Ni, Cu, Cd, Mn, Pb, Fe, and Zn were measured in the w ater column (Da- vey and Soper, personal communication 1978). Metals and total petroleum hydrocarbons were measured in tissues. Preliminary results (Phelps et al., Ms) indicate tha t levels of Ni in tissue follow levels of Ni in the water column and that highly significant differences in total hydrocarbons were observed (after two months exposure) along the transect (Fig. 4 ). Seasonal trends were observed with highest metal levels tending to occur a t low temperatures (November, December, M ay and June), and lower values during periods of high tem perature (July through October). These differences were observed at each station and suggest that two sampling periods per year may be adequate. At no time did seasonal differences override the differences in levels between stations on the transect.
During the 1977 study Mytilus were distributed along the transect a t different time periods following the initial distribution. D ata indicate that the date of collection is more directly related to tissue metal levels than is the time of exposure. For example, November tissue levels are high and comparable whether the collected M ytilus have been on station six, four, or two months. Length of exposure (after an initial three weeks) is not related to metal level in the tissues.
(SUB-SURFACE)
APPROX.
1 m
1000
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D uring 1977, physiological studies were carried out in addition to tissue residue analyses. Scope-for-growth measurements were m ade on Mytilus collected along the CEAS transect at the same time that other individual M ytilus were collected for tissue analyses. R esults (Widdows et al., in press) indicate a marked reduction in scope for growth inverse to the levels of metals and hydrocarbons observed in tissue. Scope for growth, plotted against Ni tissue and water levels illustrate this relationship (Fig. 5). A subsequent laboratory bioassay was conducted co-operatively with the US N O A A /N M FS Laboratory at Milford, Connecticut, using Ni as a toxicant. Preliminary results indicate that at higher levels of exposure to Ni, respiration rates may be directly related to observed reduction in scope for growth. However, tissue residue levels in those animals exhibiting elevated respiration rates have not as yet been determined. Gonzalez et al. (1977) demonstrated a significant reduction in the filtration rate of M ytilus exposed to 19 ppb water-soluble oil fractions. This indicates that the total hydrocarbon found as tissue residues in M ytilus from the stressed portion of the CEAS transect also may be directly related to the observed reduction in scope for growth.
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S-ANIMALS HELD IN STRESSED AREA (Sta. 2 , Fig. I) FOR 4 WEEK EXPOSURE
80 D onald K. Phelps and W alter B. Galloway
600
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400O'
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200
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42 30
CEAS STATION NUMBER
Figure 4. T otal hydrocarbon concentration in organisms. CEAS study, Narragansett Bay, R .I.
Preliminary work by Thurberg and Gould at the Milford N M FS Laboratory during the summer of 1978 showed that physiological and biochemical para meters can be helpful in interpreting the mechanisms of stress. T he coordination of data on the oxygen consumption of gill tissue and on specific serum ion concentrations with the activity of several selected enzymes of carbohydrate and nitrogen metabolism, will hopefully produce an overall metabolic profile that can be related to environmental changes. Individual metabolic abnormalities may also be useful as early warning signals of potential stress. Initial observations show promise in this respect. In mid-August, for example, gill respiration was significantly elevated in animals taken from a polluted station, as was adductor muscle transaminase activity and a gill dssue glycolytic enzyme involved in cellular redox regulation.
One shortcoming of the US Mussel W atch program has been the need to substitute different species and genera in southern ranges along both the east and
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Figure 5. Scope for growth and nickel concentration in water and organisms. CEAS study, N arragansett Bay, R .I.
west coasts and the gulf coast as well, owing to the geographic distribution limits of M ytilus edulis. Some differences in pollutant levels seen geographically may in fact be attributable to a shift in species of monitoring organism. The CEAS concept can be used on a seasonal basis in areas flagged by Mussel W atch to delineate the extent of a problem. T he use of M ytilus edulis in all cases would allow for comparisons with residue levels from well-defined pollution gradients like those of Narragansett Bay. A transect of CEAS stations in such an area could help to pinpoint the source of the pollutant as well as to confirm the existence of a problem. Small samples of Narragansett Bay CEAS M ytilus were successfully transported to and
A report on the coastal environm ental assessment station (CEAS) program 81
distributed along transects in Beaufort, North Carolina, and Corpus Christi, Texas, at different time periods but during winter months. Tissue residue analyses for metals and total hydrocarbons have been completed and the results are being analysed.
The tissue residue monitoring phase of the CEAS approach identifies those toxicants that are coming back up through the food chain from m an’s industrial discharge history, linked through the edible mussel to haunt his pallet and plague his well being. The CEAS concept must have long-term backing so that changes in toxicant loads as they affect natural resources and m an’s health may be documented through biological indicators such as the mussel. In this case, the CEAS approach becomes an im portant adjunct to Mussel Watch. Mussel W atch has identified “hot spots” of tissue residues along the coastal US. The CEAS approach can then establish toxicant levels up into estuaries and embayments. In demonstrating gradients of concentration, the mussel as a biological indicator may be used to locate sources of toxicants within an estuary and simultaneously provide evidence of physiological impairment owing to the presence of such toxicants. The combined results of Mussel W atch survey data and the more intensive backup provided by the CEAS approach provides a powerful tool for marine environmental m anagement decision-making, defining temporal and spatial problem areas, locating sources of input, and demonstrating impact on the well being of natural resources as well as potential threats to man.
R E FE R E N C E S
Alspach, S. 1978. Energetics budget betw een two populations of the quahog M ercenaria mercenaria in the Providence R iver and N arraganse tt Bay. D epartm en t of Biology, W estern M aryland College, W estm inster, M aryland 21157. (Personal com m unication).
Bayne, B. L. (E d .) . 1976. M arine mussels: their ecology and physiology. C am bridge U niv. Press, C am bridge. 495 pp.
Davey, E., and Soper, A. 1978. Environm ental Research Laboratory , N arragansett, R .I., U .S.A. (Personal com m unication) .
Farring ton , J . W ., and Q uinn , J . J. 1973. Petroleum hydrocarbons in N arraganse tt Bay. I. Survey of hydrocarbons in sediments and clams. Estuar. & Coast. M ar. Sei., 1: 71-79.
Goldberg, E. D., Bowen, V. T ., Farrington, J . W., H arvey, G., M artin , J . H ., Parker, P. L., R iseborough, R . W ., R o bertson, W ., Schneider, E., and G am ble, E. 1978. T he Mussel W atch. Environm ental Conservation, Vol. 5, No. 2, Sum m er 1978.
Goldberg, E. D ., Gamble, E., Griffin, J . J., and Koide, M. 1977. Pollution history of N arragansett Bay as recorded in sediments. Estuar. & Coast. M ar. Sei., 5: 549—561.
Gonzalez, J. G., Everich, D ., H yland, J . and M elzian, B. D. 1979. Effects of No. 2 heating oil on filtra tion ra te of blue mussels, M ytilu s edulis, L innaeus. In Advances in m arine environm ental research. U SEPA 600/9-79-035: 112—121.
Phelps, D. K ., and Galloway, W. B. 1979. T h e use of in tro duced species (M ytilu s edulis) as a biological ind ica to r of trace m etal con tam ination in an estuary. In Advances in m arine environm ental research. U SEPA 600/9-79-035: 2 6 - 37.
Phelps, D. K ., Galloway, W. B., W iddows, J . L., Davey, E. W ., Soper, A. E., and Lake, J . L. M easurem ent of m etals and petro leum hydrocarbons in mussels in troduced along the CEAS transect (a pollution grad ien t) in N arra gansett Bay. (M s.).
Phelps, D. K ., and Myers, A. C. 1977. Ecological considerations in site assessment for dredging and spoiling activities. In Proceedings of the second U .S. Ja p a n m eeting on m anagem ent of bottom sediments contain ing toxic substances, O ctober 1976. EPA Ecological Research Series, EPA-600-3-77-083.
Phelps, D. K ., Telek, G., and L apan , R . L., Jr. 1975. Assessm ent of heavy m etal distribution w ith in the food web. In M arine pollu tion and m arine waste disposal, pp. 341-348. Ed. by E. A. Pearson and E. D. F rangipane. Pergam on Press, O xford and New York.
W iddows, J . 1978. Physiological indices of stress in M ytilus edulis. J . m ar. biol. Ass. U .K ., 58: 125-142.
W iddows, J ., Phelps, D . K ., and Galloway, W. B. M easure m en t of physiological condition of mussels in troduced along the CEA S transect (a pollution g rad ien t) in N arraganse tt Bay. M arine E nvironm ental Research. ( In press).