What happened to biological effects monitoring?

ll,.In~ I'tdhttloll Ihtlhlm \ o l

I " No II p p ~()1-~92

19~4

PI IlltCd III (11, II I~111 II1|

What Happened to Biological Effects Monitoring ? There seems to be a feehng in some quarters that biological effects momtormg has not lived up to its early prormse, Indeed that, m spite of slgrnficant efforts m recent years, it has not even got properly off the ground This view perhaps arises from the fact that while there are a number of large-scale national and international momtonng programmes in operation, these do not usually have effective biological components It may be useful to put the topic into perspective One result of the increasing concern wath pollution m recent decades has been a demand for programmes of general surveillance of the manne environment The early surveys were sensibly concentrated on what could be measured reliably, and, of the vanous enwronmental compartments, were focused on biota because the relatively higher concentrations of contammants m biological tissues sLmplLfied samplmg and analysis as well as the interpretation of data Thus m the early 1970s the pioneering momtormg programmes of ICES selected a number of species of fish and shellfish for analysis, and measured several contaminants m their tissues The need was recograzed for generally accepted sampling guidelines and for agreed analytical methods before extensive cooperatave programmes could be successful, and the necessity for intercallbratlon exercises between participants was stressed This has been reflected in America where the recently established Coastal and Estuarme Assessment Programme of NOAA IS now supported by a comprehensive Quality Assurance Programme The ICES surveys have been refined over the years, and now the most Important trace metals can be determined in tissues by a wide range of laboratories wath acceptable accuracy and comparabihty The Joint Monltonng Programme of the Oslo and Paris Commissions demonstrates the feasibility of wide-scale collaborative ventures The other main enxaronmental compartments, seawater and sediments, were less amenable to routme momtorlng In seawater the normally low concentrations of contarmnants presented analytical dlfficulUes, while the pattern of water samphng which would best represent a site or a water mass was far from obvious Sediment, a partlcularly heterogeneous phase, posed additional problems for routine monltonng away from high input areas such as dumping grounds, not the least of the dlfficulues being a lack of understanding of the bioavailablllty of contanunants detected However, the development of increasingly sophisticated analytical techmques, coupled with the extensive detailed studies of I O C - G E M S I and of ICES, is making reahstic momtormg of seawater possible for at least some contarmnants, and m the light of results from internationally coordinated pilot studies in sediments at present under way m the southern North Sea, the Kattegat and the Baltic Sea, it should soon be possible to bring sediments into routine momtonng programmes if required Crown Copyright

(11125-~26X 84 $3 00+It (10 PLIg Imon Pn-ss Ltd

But these programmes are directed to the measurement of contarmnants, and it should be noted that our environmental concern, pubhc health apart, is not wath chenucals as such, but rather wath the effects they may have on plants and ammals Knowledge of the distribution of chermcals may mdicate actual or potenUal trouble spots, but the detection of a biological signal may help to focus later chemical studies, and in the context of the environment m general, the ulUmate evaluation of contamination must be made in biological terms One approach to effects studies is to translate field measurements of chenucals into forecasts of potential effects by relating them to relevant experimental work Unfortunately, it is surpnsmg how often such studies have used unreahsUcally high concentrations of contanunants, or failed to link the three stages--concentrations m the water (or sediment), residues m the tissue, and effect on the organism Another difficulty wath such experiments IS their extrapolataon to field conditions, although this can now be overcome to some extent by the use of macrocosms for long-term observations on several components of the food web The most direct and satisfactory approach, however, is to look for effects m the field--biological effects momtoring Tlus ISnot concerned merely wath the use of orgamsms m momtormg, e g wath residue levels (as m 'mussel watch' surveys) or wath bioassay-type studies It rams rather to detect and measure a response of the orgamsm to the contammant and to provide some assessment of the resulUng mapact on the ecosystem Unfortunately the great vanability of responses in hvmg orgamsms obscures all but the most obvious effects, and the diversity of reactions makes it difficult, having recogmzed a change, to attribute it to a specific cause Thus, wlule the less demanding chenucal surveys quickly became acceptably operational, additional attention had to be directed to basic problems before effects momtormg could get underway, and several international agenoes were involved Dunng the 1970s, working groups of SCOR and G E S A M P exarmned the problems of momtormg b|olog~cal variables related to marme pollution, and m 1979 some fifty scientists participated m an ICES Workshop to evaluate available approaches As a result of this activity, a wade range of possible techtuques has been proposed for biological effects momtonng, and a strategy has been developed for applymg them Nevertheless, such procedures have not so far been generally built into wade-scale routine momtormg programmes, and It may be this shortfall, together wath the failure of the popular benthic commumty momtonng approach to dehver the goods m some cases, that has generated dlsillus~onment In fact, the reality does not justify such a reaction Biological effects momtormg is at present a going concern, as testified by, for example, the work of IMER m the UK, the E S T H E R project In Sweden, and the activaties supported by NOAA and EPA m Amenca, while in UNEP's Regloaal Seas Programme, biological effects are included at least in the M E D P O L component The difficulty is that requirements for a biological effects programme are very different from those for contaminant momtonng The latter does demand rigorous methodology, but usually

1984

391

Marine Pollutum Bulletin

calls for expertase and equipment which may be found in any good chenucal laboratory, and employs techniques wbach are probably part of the daffy activity of such laboratories The techmques available for biological effects momtonng, on the other hand, are much less standardized and amenable Thus the 50 or so approaches discussed in the reports referred to above are based on such vaned disciplines as biochemistry, cytology, pathology, behavlour and morphology, the range of expertise and equipment required is enormous and the difficulties of intercahbratlon formidable For example, one group of techmques relates to the measurement of some aspect of the energy metabolism of the ammal e g 'scope for growth, glycolytlc enzyme activity levels, adenylate energy charge, oxygen consumption/nitrogen excretion ratios, hepatic glycogen levels, and these have been used successfully to assess the well-being of sessile antmals along well documented pollution gradients However, smce energetlcs and growth are also natural variables, these measurements may not be comparable, even withm a species, over wider geographical areas Other techmques relate either to a specific response to a contaminant or group of contammants (e g M F O and m e t a l - b i d i n g proteins) or are themselves mdlcative of tissue or cellular damage (eg cytological techniques such as lysosomal fraglhty or hlstopathological conditions such as tissue hyperplasla) and are less hkely to be the result of natural environmental changes A further group of techmques may be placed somewhere between bloassay and biological momtonng, since they revolve either exposing animals in cages m the environment or preparing extracts of water or sediments for laboratory-based tests with animals or ammal tissues For example, the sister chromatld exchange technique has been used to measure mutagenlclty in the mussel Myttlus eduhs exposed to environmental mutagens and it may be possible to use caged mussels in a biological momtonng programme to test for mutagemc substances in the marine environment Given thls range and complexity, it is hardly surprising that it is not easy to provide a shopping list of techmques which can be routmely used, built into existing momtonng programmes, and applied and mterpreted with confidence by the partlc~ants of such programmes in different laboratories from several countries This explains why biological effects momtoring techniques, although widely used, are at present being applied mainly in the context of site-specific problems, where a single laboratory is involved, and operates those approaches with whtch it has particular experience Examples are the use by I M E R of biochemical, cytological and physiological techniques on molluscs to study the effects of oil at Sullom Voe, the use, by the Aberdeen Marine Laboratory, of enzyme induction m fish to detect oll effects in the North Sea, and the widespread use of changes in the structure of benthic populations to delineate the effects of dumping, for example, sewage sludge and oil-based mud cuttings The last of these approaches, the use of benttuc population structure, illustrates the different requirements of

392

site-specific and general monltonng In situations like dumpmg grounds, where there is a specific source of input and the contammant levels near the source are high, changes in the structure of benttuc commumtles along a gradient can be valuable m tracing effects But in the absence of a hot spot, the great natural vanablhty m benthlC communities makes it almost impossible, as has been well demonstrated recently for rocky shores, to attnbute cause unequivocally to any changes detected There is a suggestion that analysmg changes m the dlstnbutlon of individuals among species imght offer help in detecting pollution-related effects, but it is probably only in relatively umform habitats where commumty studies have been conducted for many years, such as the subtldal sediments off Northumberland, that there may be hope of adequately lnterpretmg changes m the context of low level contammatlon, and even such mstances are probably localized rather than regional Thus, the challenge with biological effects momtorlng comes in attempting to apply techmques, valid for sitespecific studies, on a wide-scale routine basis Some such techniques are hkely to be too demandmg in expertise or equipment for widespread use, too labour-Intensive or long-term for routine work, too sophisticated for cooperative surveys There are two solutions The first is to accept that, given the complexity and demanding nature of many otherwise attractive biological effects momtormg techtuques, it is best not to seek the umformlty of approach that is possible in a chemical monmtormg programme, but rather to register whatever techmques may be offered by partlcipatmg laboratories, recognizing that in spite of the resulting mosmc, at least some effects evaluation will be possible The second is to select from the techniques available those which are sufficiently straightforward to be applied without extensive development or traimng in large-scale routine programmes ICES has been attempting to identify such techmques, and those which appear to be most suitable include certain pathological conditions (lncludmg skeletal anomalies and some s k i diseases) in fish, M F O measurements, levels of metal binding proteins, lysosomal fragility, histopathology, and possibly some caged mussel deployment Since some of these techmques can be conducted on small pieces of tissue (usually kidney or liver), suitable samples could be collected and preserved during a chemical momtoring programme and later assayed at statable laboratories Finally, it IS worth noting that the current successful chenucal monltonng programmes were built on the practfcal expenence of earlier failures and deficiencies If practmoners had delayed action pending the development of a perfect plan, they would still be talking In the case of biological effects monitoring, promising techmques do exist and a field trial is now essential It is relevant that ICES plan to conduct an extensive baseline survey of contalmnants in fish and shellfish in the North Atlantic in 1985 and is encouragmg associated biological effects observations It is to be hoped there will be a good response A D MclNTYRE