express thanks to Paul Dudley-Hart of Alpine Geo-physical Associates, Inc., whose knowledge of Span-ish and of human nature made smooth manyawkward situations, and whose knowledge ofequipment saved us from mistakes and, sometimes,losses. We also express our appreciation to all mem-bers of the U.S. and Argentine parties for theirhard work and pleasant companionship. This re-search was supported by National Science Founda-tion grant Opp 74-08565.

A total of 101 samples were taken: 13 near thebottom with a Hensen net, 10 near the bottom witha Clarke-Bumpus net, 16 at intermediate depthswith a Hensen net, 27 at intermediate depths witha Clarke-Bumpus net, 33 with a Hensen netdragged horizontally, and two of 0- to 30-meterplankton with an Isaacs-Kidd net.

Behavior of live Euphausia superba was monitoredin the ship's laboratories in an experiment that con-tinued until several days after the return to BuenosAires.

ARA Islas Orcadas cruise 5:marine biology

A. P. ToMoDirrección Nacional del Antártico

Buenos Aires, Argentina

Cruise 5 of the Argentine navy ship ARA Islas Or-cadas began at Buenos Aires on 3 May 1975 andended at this port on 19June. The area worked wasin the vicinity of South Georgia Island and the SouthSandwich Islands. The members of the Argentineteam who made the trip are: Enrique Marschoff(chief of the onboard Argentine group), GustavoCarrara, Carlos Duprez, and Luis A. Gonzalez,of the Argentine Antarctic Institute; RichardFerriz, Guillermo Padilla, and Pascual Topa, of theArgentine Museum of Natural Sciences, "Bernar-dino Rivadavia."

Onboard research was conducted according totwo work plans approved by the national Office ofthe Antarctic: zooplankton were studied by insti-tute personnel, and benthic fauna were studied byinstitute and museum personnel in collaboration.

Zooplankton. Conventional zooplanktonic samp-ling was done along the ship's track by Hugh H.DeWitt, University of Maine, who was chief scientistof the cruise. Near-bottom waters were sampled—proximity to the bottom was maintained by sonar—to detect krill eggs and larvae. Large quantities ofzooplankton were collected using an Isaacs-Kiddnet, although we soon had to stop using it becauseof winch difficulties.

Qualitative and quantitative samplings weretaken in vertical sweeps using Hensen and Clarke-Bumpus nets. Surface samples were taken using asmaller Hensen net towed by the ship. At stations,samples were taken at selected depths verified bysonar.

Benthic fauna. To obtain information concerningfish abundance, sweeps were made with benthicnets of the otter-trawl type. Twenty-four sampleswere obtained: 18 with a 40-foot ott ;r net, fourwith a 10-foot otter net, two with a large otter netfrom the museum.

The material is being processed for uantitativedetermination of population dynamics, taxonomy,ecology, abundance, geographic distribution, andother factors.

Good collaboration with the U.S. group per-mitted us to collect more than the planned num-ber of samples. Aboard ship, a device was made topermit the same casting to invert and close a Nan-sen bottle very near the bottom, after carrying outa vertical sweep of variable duration with a Hensennet that sampled the water at the bottom. This inno-vation permitted measurement of bottom tempera-tures (primarily of interest to the U.S. team) andsweeping of the bottom water (of interest to theArgentine Institute group).

We thank the Argentine navy crew of Islas Or-cadas for their dedicated support.

Ecology of fishes andechinoderms: RN Hero cruise 76-2

EDGAR F. LOWE and RICHARD E. CRAWFORDDepartment of Zoology

University of Maine, OronoOrono, Maine 04473

The ecology of demersal fishes and echinodermswas studied in January, February, and March 1976aboard RIV Hero cruise 76-2 in the vicinity of An-vers Island (64°33'S. 63°35'W.), south to Adelaide

June 1976 53

I

John H. Dearborn

Giant fulmar chick on nest at Bonaparte Point, Anvers Island.The bird has impaled a limpet shell on its mandible. Thissometimes occurs as chicks forage around the nest site

where limpet shells are dropped by adult birds.

Island and Marguerite Bay, and ashore at PalmerStation on Anvers Island. These investigations con-tinued field and laboratory studies begun by Uni-versity of Maine personnel aboard ARA Islas Orcadascruise 5 in May and June 1975. As graduate stu-dents in the Department of Zoology, we conductedthe field research this year under the direction ofJames D. McCleave and John H. Dearborn.

A total of 49 stations ranging from intertidal todepths of 750 meters were sampled as well as sev-eral terrestrial stations. The following gear wasused: a 5-foot Blake Trawl (beam trawl), an OtterTrawl, a 3-foot Beam Trawl, an epibenthic sled,fish traps, long line, hand line, and hand collectingin intertidal and terrestrial locations.

Our objective this year was to obtain data on theecological energetics of abundant benthic inverte-brates (especially echinoderms) and fishes. In thiscontext, selected tissues or whole specimens ofasteroids, ophiuroids, crinoids, holothurians, andechinoids were frozen or dried and shipped to theUniversity of Maine where the biochemical compo-sition (i.e., total calories, water, ash, protein, lipid,and carbohydrate) will be determined by standardmethods. From aboard Hero we were fortunate toobtain gravid specimens of the shrimps Chorismusantarcticus and Notocrangon antarcticus and somebrooding asteroids and echinoids. These specimenswere frozen with eggs or broods and were sent toMaine for similar analyses. During intertidal col-lecting, specimens of amphipods and the limpetPatinigera polaris were obtained. This limpet is animportant component in the diet of antarctic birds

(figure), especially the southern black-backed gull,Larus dominicanus, nesting along the AntarcticPeninsula (W. Fraser, personal communication).Therefore a seasonal study of the biochemicalcomposition of this limpet was initiated in coopera-tion with William Fraser, a graduate student at theUniversity of Minnesota working under the direc-tion of David F. Parmelee. Information from thiscooperative effort will be used to help understandinteractions between gulls and limpets over an ant-arctic year.

Invertebrate studies at Palmer concerned two ex-tremely abundant echinoderms, Ophionotus victoriae(Ophiuroidea) and Odontaster validus (Asteroidea).These organisms were maintained in flowing sea-water to study feeding rates, growth, and changesin biochemical composition during starvation.Ophionotus studies were finally abandoned becausespecimens would not feed well in the laboratoryand showed a high frequency of arm autotomy.Odontaster validus, however, were maintained with-out difficulty in the laboratory and individuals wereeither tagged or isolated so that growth and feedingrates could be followed. Odontaster fed on a varietyof foods, including ophiuroids and other asteroids.For feeding rate studies Odontaster were maintainedon a fish or shrimp muscle diet. Data from thesefeeding studies are being analyzed.

Fish studies at Palmer included investigation ofgastric evacuation rates of Notothenia coriicepsneglecta. This species was maintained in the newlyrefurbished seawater system, which provided excel-lent holding conditions. Similar studies on N. gib-berfrons were begun aboard Hero and concluded atPalmer. Further work on the digestive physiologyof N. coriiceps neglecta and N. gibberfrons is underway at the University of Maine and includes investi-gation of the morphology and histology of thegastrointestinal tract and examination of the acti-vities of digestive enzymes.

N. coriiceps, N. gibberfrons, and N. nudfrons speci-mens were frozen for shipment to Maine whereanalyses of tissue lipids, proteins, ash, water, andcalories will be done. The effects of starvation andexperimental feeding on tissue composition werestudied at Palmer Station. This work is expected toyield useful data on the bioenergetics of these abun-dant antarctic fish. Growth rate determinations forthese three fish species are also being made byexaminations of scales and otoliths.

To study resource partitioning and feedingchronology of benthic fish, tows were made with a5-foot Blake trawl at depths of 50 to 100 meters offDriencourt Point, Brabant Island. Five tows weremade over a 24-hour period and the fish collectedwere measured and weighed. Dissected stomachswere preserved and returned to Maine where Dr.

54 ANTARCTIC JOURNAL

Is

::

•'.11..:'

McCleave and Timothy E. Targett will determinethe gut contents.

Some echinoderm and fish specimens were col-lected and preserved for taxonomic purposes.Fishes of the families Channichthyidae, Bathydro-conidae, Liparidae, and Zoarcidae were obtainedand will be examined by Hugh H. DeWitt, Uni-versity of Maine. Some heart urchins were col-lected for examination by F. Julian Fell, Univer-sity of Maine, while crinoids and asterozoans willbe determined by Dr. Dearborn.

We extend our appreciation to Captain Pieter J.Lenie and the crew of RJV Hero for their enjoyablecompany, their cooperation, and their excellentfield support. We also thank William Showers, agraduate student at the University of California,Davis, for field assistance. This study was supportedby National Science Foundation grant o pp 74-08565.

Biology of krill(Euphausia superba) and other

antarctic invertebrates

M. A. MCWHINNIE, C. DENYS, and D. SCHENBORNDepartment of Biological Sciences

De Paul UniversityChicago, Illinois 60614

These studies began upon our arrival at PalmerStation on 28 November 1975 and ended when RIVHero departed on 9 March 1976, at the end of theaustral summer. Throughout the season 152pelagic and 16 bottom samples were collected(Isaacs-Kidd midwater and conventional benthictrawls, respectively) aboard Hero (cruise 76-2) dur-ing 24 days at sea. Other benthic and pelagicsampling was accomplished in Arthur Harborusing Zodiak boats. Sampling of krill at five depths,mostly between 500 meters and surface, was usuallyconducted from dusk to dawn. Sampling through

4-

I'II''I

Figure 1. Krill sample being brought aboard RN Hero by Captain Lenle. Figure 2. Krill stations occupied In December 1975 andJanuary 1976 between Daliman Bay of Brabant island and the Argentine islands, north and south of Palmer Station (P).

June 1976 55