Effect of moult on crude oil load in a jackass penguin Spheniscus demersus

Marine Pollution Bulletin effect preceding the more serious effects from increased pollutant l o a d - - d r o p in diversity and elimination of nontolerant s p e c i e s - - c o m m o n to both organic and toxic pollution. Utility of the log-normal distribution method indeed seems superior to other methods in assessing moderate or early-stage organic pollution impact (Gray & Pearson, 1982; Gray, 1983). The present investigation was concerned with animal communities of the boreoarctic and boreal zoogeographical zones of the northwestern Atlantic. Following the classification of Jones (1950) the communities encountered were of the boreal offshore m u d association or deep mud association types. T h e pollution indicator species groups defined may not apply to other habitat types or zoogeographical regions.

Hovgaard,P. (1973). A new systemof sieves for benthic samples. Sarsia 53, 15-18. Hurlbert, S. N. (1971). The non-concept of species diversity.Ecology 53, 577-586. Jones, N.S.(1950).Marinebottomcommunities. Biol. Rev.25,283-313. Mirza,EB.&Gray, J.S.(1981).Thefaunaofbenthicsedimentsfromthc organically enriched Oslofjord, Norway. J. exp. mar Biol. Ecol. 54, 181-207. Pearson, T. H. (1975). Benthic ecologyof Loch kinnhe and Loch Eil, a sea-lochsystem on the west coast of Scotland. IV. Changes in the benthic fauna attributable to organic enrichment. J. exp. mar. Biol. EcoL 20, 1-41. Pearson,T. H. & Rosenberg,R. (1978). Macrobenthic succession in relation to organic enrichment and pollution of the marine environment. Oceanogr. Mar. BioL Ann. Rev. 16,229-311. Rygg,B. (1984). Blotbunnfaunaundersokelser. Etgodt verktoy red marine resipientvurderinger.Report. Norw. Inst. Water Research, Oslo. Rygg,B. (1985a). Effect of sediment copper on benthic fauna. Mar. Ecol. Prog. Ser. 25, 83-89. Rygg, B. (1985b). Heavy-metalpollution and log-normaldistribution of individuals among species in benthic communities. Mar. Polha. Bull. (in press). Rygg,B. & Skei, J. (1984). Correlation between pollutant load and the diversityof marine soft-bottom fauna communities. In Proceedings of

Bagge, P. (1969). Effects of pollution on estuarine ecosystems.I. Effects of effluentsfrom wood-processingindustries on the hydrography,bottom and fauna of Saltk/illefjord (W. Sweden). Meerentutkimuslait, julk. 228, 3-118. the International Worl~'hop on Biological Testing on Effluents" (and Gray, J. S. (1983). Use and misuseof the log-normalplotting method for Related Receiving Waters). OECD/U.S.EPA/Environ. Canada, pp. detection of effects of pollution--a reply to Shaw et al. (1983). M a r . 153-183. Ecol. Prog. Ser. 11,203-204. Sanders, H. L. (1968). Marine benthic diversity: a comparative study. Gray, J. S. & Pearson, T. H. (1982). Objective selection of sensitive speAm. Nat. 102,243-282. cies indicativeof pollution-induced change in benthic communities. I. Shannon,C. E. & Weaver,W. (1963). The Mathematical Theory of CornComparative methodology.Mar. EcoL Prog. Ser. 9, 111-119. munication. UniversityIllinois Press, Urbana.

MarinePollutionBulletin.Vol.16.No.12,pp.474-476.1985

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Effect of Moult on Crude Oil Load in a Jackass Penguin Spheniscus demersus G. I. H. K E R L E Y , T. E R A S M U S and R. P. M A S O N * D e p a r t m e n t o f Zoology, Universityof Port Elizabeth, P.O. B o x 1600, Port E l i z a b e t h 6000, R.S.A. *Sea Fisheries Research Institute, Private Bay X2, Roggebaai, 8012, R . S . A .

Induced moult has been suggested as a technique for rehabilitating oiled seabirds. An oiled jackass penguin underwent natural moult in captivity. Analyses of oil extracted from premoult and postmoult feathers indicate little qualitative difference, with significant amounts of oil transferred from premoult to postmouit feathers, Inducing moult, therefore does not appear to be viable for cleaning oiled seabirds,

hens (Ishigaki etaL, 1971)and could possibly be induced in seabirds. It is not known whether any such attempts have b e e n carried out, although it has been reported that oiled seabirds which had been cleaned by other techniques, regained s o m e or all of their natural waterproofing after having undergone a natural moult (Clark, 1978). This report deals with our observations of moult in an oiled jackass penguin Spheniscus demersus.

Although the actual impact of oiling mortality on seabird populations has proved difficult to determine (Dunnet, 1982), it is generally recognized that cleaning and rehabilitation of oiled seabirds is desirable, both from a conservationist point of view as well as for humanitarian reasons. Much effort has been directed at investigating techniques for treating oiled seabirds. Success rates depended on both the type of oil and bird species involved. It has been suggested that a possible technique to clean an oiled bird would be to induce feather-moult and then allow the bird to rid itself of the oiled feathers (Bourne, 1968). Moult has been induced in domestic

Methods

474

During the course of an investigation into the effects of crude oil (applied to the feathers) on digestion in jackass penguins, an oiled and an unoiled control bird underwent natural moult simultaneously. The oiled bird had been experimentally oiled with 75 g of partially weathered (8 h in the sun) Q a t a r Marine crude oil 3 days prior to the start of moult. Both birds were maintained at 21°C with natural humidity and light regime and fed pilchards Sardinops ocellata ad lib.

Thirteen days after the start of moult (near the end of

Volume 16/Number 12/December 1985

moult, Randall, 1983), the oiled bird died. A sample of loose, premoult feathers (sample B) were plucked from the abdominal area and a sample of postmoult feathers (sample C) was clipped from an adjacent area that had been moulted. A sample of postmoult feathers were clipped from a comparable area on the control bird (sample A). Oil was extracted from the feathers with dichloromethane and the extracted samples dried with anhydrous sodium sulphate. Analyses of these samples were carried out against the Qatar Marine crude oil standard with both gas chromatography (GC) and fluorescence, The GC runs were performed on a Packard Series 437 gas chromatograph with a 25 m OV-101 wall coated open tubular capillary column with an inlet splitter and a flame ionization detector. The injector port temperature was 270°C, the detector was 300°C. The oven remained at 70°C for the first 4 min of each run and then increased at 6°C min-~ until 300°C. Each run was monitored for 40 min. The sample size injected and the recorder attenuation were the same for all runs. The crude oil standard was 1642 mg 1-1. Two types of fluorescence analysis were performed on the extracted samples following Keizer & Gordon (1973) and Gordon & Keiser (1974). Measurements at previously determined fixed wavelengths produced reasonable estimates of three aspects of the oil present (in the extracts): (i) the overall oil concentration (excitation (Ex) and emission 0Era) wavelengths of 280 nm and 374 nm respectively); (ii) the diaromatic content (Ex= 290 nm; E m = 3 4 2 nm) and (iii) the heavy aromatic content 0EX----290 ran, E m = 4 0 6 nm), with reference to the crude oil standard. Furthermore, an overall impression of the range of the aromatic fraction was obtained with a fluorescence scan using changing excitation and emission wavelengths (with a constant difference of 20 ran). The samples were quantified against previously constructed calibration curves using the three sets of wavelengths described above,

Results Both birds appeared to undergo normal moult. Visual observation of the oiled bird indicated the presence of oil on postmoult feathers in moulted areas. The plots of the synchronous fluorescence scans of the extracted samples and the standard crude oil are presented in Fig. 1. Both the premoult and postmoult feathers of the oiled bird show significant amounts of oil while the unoiled control bird appears to be free of oil poilution. When these are compared to the crude oil standard, it can be seen that the shoulder between 310 and 340 nm is relatively less pronounced in the feather extracts. This could indicate the relative loss of the lighter aromatic fractions. Comparing the equivalent crude oil/feathers as mg gobtained from the excitation 280 nm, emission 374 mn peaks (Table 1) it can be seen that the oil content of the postmoult feathers (C) is about twice that of the premoult feathers (B). By comparison the postmoult feathers of the control bird (A) must be considered clean with a value of less than 0.5% of the other samples. The relative emission intensities calculated in Table 2 for the crude oil standard and the two oiled samples indicate that the premoult and postmoult feathers of the oiled bird are similar as far as their aromatic content is concerned supporting information presented in Fig. 1. When compared to the crude oil standard, these ratios indicate a decrease in the 290/342 TABLE1 lengthfluorescencepeakheights.

Equivalents of mg crude oil g-l of feathers calculated from fixed wave-

Sample

Unoiled control

Oiled Oiled Crude oil premoult postmoult standard

Feather dry mass (g)

A 0.34

B 1.15

C 0.44

--

16.4 ppm

Equivalent

Ex 280

Em 374 0.55

224

445

16.4

oil from

290

406 0.55

238

469

15.9

mgg-~crude 290 342 0.47

155

346

16.4

(ii)

I-Z IM F-

z_ (iii)

(iv)

i 520

i 460

, 400

, 340

, 520

, 460

i 400

i 340

WAVELENGTH (nm)

Fig. 1 Synchronous fluorescence scans of oil extracts: (i) premoult feathers; (ii) postmoult feathers; (iii) control feathers; (iv) crude oil standard (1642 mg l-l). Note that (i) and (ii) are diluted 1:125 while (iii) is undiluted.

475

Marine Pollution Bulletin

TABLE2

moult feather sample was clipped and consisted of the

Calculated fixed wavelength relative emission intensities where I ~ ratio of E x ~ 2 8 0 nm, E m z 3 7 4 nm and E x ~ 2 9 0 nm; E m = 3 4 2 nm; I I z ratio of Ex - 280 nm, Em -- 374 nm and Ex - 290 rim, Em - 406 rim; IIl~ratio of E x - 2 9 0 rim, E m - 3 4 2 nm and E x - 2 9 0 nm, E m ~ 4 0 6 nm. Sample I II III

distal feather portions only, excluding the heavy, low surface area (i.e. less area for oil to be attached) feather

shafts.

peak relative to the 280/374 peak, an increase in the 290/406 peak relative to both the 280/374 and 290/342 peaks. This indicates the loss of some of the lighter aromatics, with relatively more heavy aromatics present in the oiled feather samples than in the crude oil standard, This would support the idea that the oil on the feathers has undergone weathering, The GC results indicate (Table 3) that there were no major differences in the relative (to C20) peak heights of the n-alkanes in the oiled feather samples, supporting the observed similarity in composition of the oil on the premoult and postmoult feathers. Both these samples exhibited an apparent paucity of short carbon chains, with a concomitant relative concentration of the longer carbon chains compared to the crude oil standard, an indicator of weathering,

It is evident that feather moulting does not rid a bird of its oil load. A proportion of the oil will however be removed with the moulted feathers. Oil is probably transferred between the two generations of feathers by direct contact of the new postmoult feathers with the oiled premoult feathers. When first emerging from the follicles the new feathers would also be in contact with oil on the skin of the bird. Furthermore the preening activity of the bird during moult would tend to spread oil from oiled premoult areas to potentially clean postmoult areas. This transfer of oil between feather generations would presumably occur on a wider scale in those taxa where moult is an extended gradual process, as opposed to the rapid, total moult observed in the penguins. Induced moult does not therefore appear to be a promising method for cleaning oiled seabirds. It is likely that induced moult, with its high energy demands (Croxall, 1982) would cause a significant mortality in already stressed oiled seabirds. This would be a particular problem in those seabirds which undergo a total moult in a short period of time.

TABLE 3 n-Alkane peak heights (relative to the C20 peak) obtained by gas chromatography for the oiled premoult (B) and postmoult (C) feather extracts.

This work was supported by the Department of Transport, the Council for Scientific and Industrial Research and the University of Port Elizabeth.

Oiled premoultB Oiled postmoult C Crude oil standard

Peak Ci5 C16 CI7 Ci8 CI9 C20 C2~ C22 C23 C24 C2s

1.54 1.57 1.24

Relative peak height B C 0.03 0.05 0.40 0.50 0.72 0.80 1.00 1.10 1.03 1.08 1.00 1.00 0.94 0.98 0.82 0.88 0.72 0.75 0.68 0.68 0.63 0.60

1.05 1.06 1.16

0.68 0.68 0.93

Crude oil Std. 1.29 1.34 1.17 1.20 1.03 1.00 0.97 0.86 0.71 0.63 0.60

Discussion The difference in oil load on the premoult (224 mg g-t oil on feathers) and postmoult (445 mg g-t) feathers found here is possibly a sampling artifact. Entire premoult

feathers, as moulted by the bird, were collected, including the relatively heavy feather shafts. However the post-

476

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