ALBERT

Description: The beaks of 9,994 cephalopods of 61 species, obtained mainly from chick regurgitations of wandering albatrosses (Diomedea exulans L.) at Gough, Auckland, Antipodes, Prince Edward and Macquarie Islands and South Georgia, were used to specify and calculate the biomass of cephalopods consumed. Histioteuthidae were most important by numbers and biomass at Gough Island (in warmest seas), but Onycboteuthidae increasingly superseded them southwards; Kondakovia longimana formed 59 to 75% of biomass eaten at the three localities nearest the Antarctic Polar Front. Other important families were Octopoteuthidae, Cranchiidae, Architeuthidae (juveniles) and Ommastrephidae (South Georgia only). Most frequently eaten were Histioteuthis atlantica 13.7%, Galiteuthis glacialis 12.4%, H. eltaninae 12.0% and Kondakovia longimana 11.6%. Wandering albatrosses rearing chicks can forage at least to 3,000 km in a single foray, and may exploit an important food source about 1200 km from the nest (as in the probable commensalism of South Georgian birds with the Falkland Islands fishery). They feed, sometimes opportunistically, on cephalopods active or moribund at the surface, or discarded or lost by trawlers, cetaceans or seals. Vertically migrating cephalopods, especially bioluminescent species, are disproportionately frequent in their non-commensal diet, suggesting that they often feed at night.

Description: A link is proposed between the processes that led to the evolution of large species of squid and the highly variable, cyclic recruitment seen in squid fisheries. Maximum growth requires maximal feeding and minimal routine metabolism at optimum temperatures, which decrease as squid grow. Topographically induced upwelling zones, inshore of western boundary currents, provide productive environments with appropriate temperatures for all life stages. Most squid are small and live in the tropics or subtropics; locomotor constraints prevent them from swimming long distances. Long annual migrations to spawn upstream in current systems require short-lived squids to maximize rates of growth. Therefore, such systems provide the opportunity and a powerful selective advantage for large size and rapid growth. Increased fecundity and cannibalism provide additional directional selection for large individuals. Current systems show food production peaks (blooms); paralarval release must match these to increase survival. Because squid are semelparous, disruption of delicately balanced lifecycles by physical events can virtually annihilate stocks. Recovery probably requires that populations of large squid "re-evolve" from smaller, more-stable tropical populations of small squid. This recovery phase may extend the "down-side" of abundance cycles. Studies of squid/current systems have focused on western boundary currents, but the Illex complex also associates with eastern boundaries. Such populations are generally smaller than in larger systems, supporting the hypothesis, but more detailed comparisons are required.

Description: During a cruise in March 1988 dedicated to investigation of the marine resources of South Africa's continental slope, 62 species in 22 families of Cephalopoda were collected from the Cape Canyon and Cape Point Valley. Multivariate analysis revealed a clear distinction between cephalopods of the upper and lower continental slope in both benthic and epibenthic habitats. Todaropsis eblanae and Todarodes angolensis were indicator species for the upper slope benthic, from 300 to 500 m, but on the lower slope, in 700–900 m of water, they were replaced by Histioteuthis miranda and Opisthoteuthis agassizii. In the epibenthic, both upper and lower slopes were dominated by Abraliopsis gilchristi and Lycoteuthis ?diadema, but other species characteristic of the lower slope were the oceanic species Mastigoteuthis hjorti, Ctenopteryx sicula and Taonius sp. A. Cranchia scabra indicated the presence of oceanic water at stations 700–900 m deep. Other species of significance in the catches were Todarodes filippovae, Histioteuthis macrohista, Rossia enigmatica and Bathypolypus valdiviae. Species affinities indicate that the cephalopod fauna of the southern African continental slope includes the following zoogeographic components: southern African endemic, circum-Subantarctic species associated with Antarctic Intermediate Water, circum-global southern tropical/subtropical, tropical Indo-Pacific and cosmopolitan tropical/subtropical.

Description: Literature on trophic relationships in the Benguela ecosystem has stressed the importance of cephalopods as prey of groundfish. The groundfish community of the shelf and upper slope of southern Africa is dominated by the Cape hakes, and the results presented (1984–1991) confirm that both species of hake are important predators of cephalopods, especially taking into consideration the abundance of hake in the ecosystem. However, geographic, seasonal and species variability are evident in the patterns observed. The main prey species are Sepia spp. (predominantly Sepia australis), Loligo vulgaris reynaudii, Todaropsis eblanae and Lycoteuthis ?diadema. The last-named is an important food organism for fish. Its systematic status needs revision, however. Qualitative results of studies of cephalopod predation are also provided for kingklip and monkfish.

Description: Cephalopods of importance in the Benguela ecosystem include Loligo vulgaris reynaudii, Todarodes angolensis, Todaropsis eblanae, Lycoteuthis ?diadema, Sepia australis, Octopus spp. (up to three species) and Argonauta spp., and possibly also Ocythoe tuberculata and Rossia enigmatica. Species which may prove important as a result of further research are Lolliguncula mercatoris, Ommastrephes bartramii, Todarodes filippovae, Histioteuthis miranda and Abraliopsis gilchristi. "Importance" is defined on the basis of "survey abundance" (including commercial fisheries) and their trophic links with other organisms. Use of the latter criterion indicates that Sepia australis, Todaropsis eblanae and Lycoteuthis ?diadema are sufficiently abundant to be exploited by fisheries. Unknown factors are dispersal, availability and market considerations. The only examples of cephalopods feeding on commercial species of fish are Loligo v. reynaudii feeding on anchovy Engraulis capensis and Cape hakes Merluccius capensis and/or M. paradoxus in the southern Benguela and Todarodes angolensis preying on Cape hake in the northern Benguela. Such feeding is opportunistic and is not believed to threaten the fish stocks. Predators of cephalopods are mostly opportunistic, switching to other prey when cephalopods are not available. There is no evidence that such predators pose a threat to the Loligo fisheries. The opportunistic nature of cephalopods as prey and predators makes quantification of predation (in both directions) difficult. Data for such quantification are, as yet, unavailable.

Description: The results of ichthyoplankton surveys carried out by the Instituto Nacional de Pesca (INAPE) in the Argentine–Uruguayan Common Fishing Zone (AUCFZ) in summer 1980 and the winters of 1980–1982 are presented. In addition, the results of joint research with INIDEP, the Argentine and Japan Fisheries Agency, on larvae, juveniles and adults of the short-finned squid Illex argentinus carried out in winter 1989 are given, as are data obtained during the joint sardine and anchovy recruitment project carried out by R.V. Meteor in November/December 1989. The short-finned squid Illex argentinus is the most important cephalopod resource of the area, and an extended fishery is carried out on the Patagonian shelf and in the proximity of the Falkland Islands. The fishing season in the AUCFZ, for pre-spawning and spawning animals, extends from early autumn to winter (March–August). Abundance of rhynchoteuthion larvae (417–485 larvae·10 m−2) was greatest in winter in surface temperatures of 12,1–16,9°C and surface salinities of 34,8 – 35,2 × 10−3. The distribution of the larvae is related to the western boundary of the Brazil Current and the convergence front.

Description: The question whether the chokka squid Loligo vulgaris reynaudii resource can be managed effectively is examined in the light of developments in the fishery and knowledge of the resource gathered in recent years. The history of the fishery since its inception in 1985, management controls and the current state of knowledge of stock identity, distribution, seasonality and abundance, life cycle and population dynamics are reviewed as a background to a discussion of management alternatives. Long-term measures, such as fleet limitation, seasonal closures and de facto closed areas and size limits, all appropriate in the early stages of a fishery when knowledge is limited, should be replaced by more-flexible alternatives as knowledge improves. Methods of stock assessment, stock-recruitment studies and further basic biological analyses are recognized as being crucial to improving management methods. An explanation embracing physical oceanographic features and plankton productivity in the vicinity of the spawning grounds is advanced for the mechanisms underlying hatchling survival. The possible contribution of trophic studies to squid management is recognized. Effective management of the chokka squid resource is concluded to be possible provided that the specific areas needing attention be addressed by means of goal-orientated research. Rational, but not necessarily optimal, management decisions can, however, be made even in the absence of stock-recruitment data, by the employment of common-sense measures which generally include some form of effort control.

Description: The results of ichthyoplankton surveys carried out by the Instituto Nacional de Pesca (INAPE) in the Argentine–Uruguayan Common Fishing Zone (AUCFZ) in summer 1980 and the winters of 1980–1982 are presented. In addition, the results of joint research with INIDEP, the Argentine and Japan Fisheries Agency, on larvae, juveniles and adults of the short-finned squid Illex argentinus carried out in winter 1989 are given, as are data obtained during the joint sardine and anchovy recruitment project carried out by R.V. Meteor in November/December 1989. The short-finned squid Illex argentinus is the most important cephalopod resource of the area, and an extended fishery is carried out on the Patagonian shelf and in the proximity of the Falkland Islands. The fishing season in the AUCFZ, for pre-spawning and spawning animals, extends from early autumn to winter (March–August). Abundance of rhynchoteuthion larvae (417–485 larvae·10 m−2) was greatest in winter in surface temperatures of 12,1–16,9°C and surface salinities of 34,8 – 35,2 × 10−3. The distribution of the larvae is related to the western boundary of the Brazil Current and the convergence front.

Description: The population size and breeding success of Emperor Penguins Aptenodytes forsteri at the Auster and Taylor Glacier colonies were estimated during the 1988 breeding season. At Auster a total of 10 963 pairs produced about 6350 fledglings for a breeding success of 58%. At Taylor Glacier about 2900 pairs raised 1774 fledglings for a breeding success of 61%. Fledglings left Taylor Glacier over a period of 33 days at a mean mass of 10.56 kg.

Description: This paper presents an idea on the possible structuring effect of hex actinellids on Antarctic sponge associations. To this end, information derived from underwater photography performed on the eastern Weddell Sea shelf is reported and original trawl data are presented. Underwater photography shows the existence of different sponge associations; species poor associations are connected to soft bottom, species rich associations exist on substrates characterized by bryozoan debris and especially sponge spicule mats. The trawl. catches show differences in the population structure of a hexactinellid sponge, Rassella racovitzae Topsent at two stations, distinguishable from each other by substrate structure. On average small and therefore probably young specimens were found on bryozoan debris, while a population with larger and probably older specimens was found on solid hexactinellid spicule mats. These observations form the basis for the hypothesis that hexactinellid sponges are a major biological structuring agent for Antarctic sponge associations; they colonize soft substrate and bryozoan debris dominated areas and subsequently change the quality of the substrate by spicule deposition. The ensuing spicule mats are a suitable settling ground for a large number of demosponge species dependent on hard substrates. Mass occurrences of hexactinellids are also found in areas other than Antarctica. The phenomenon recognized in the Weddell Sea probably occurs more widely spread.

Description: A method is proposed for cloud detection over sea using a single infrared channel of a high spatial resolution satellite radiometer. The method combines a spatial coherence test and an absolute threshold test for the temperature field. The threshold for the second test is automatically determined by a histogram analysis of data which were preselected by the coherence test. The coherence test used differs from the classical standard deviation test in the way of the test value computation: the weight of the pixel to be investigated is increased. A simulation shows that under conditions of low cloud cover this makes the proposed coherence test more sensitive than the standard deviation test. When applied to real data the test was also found to be very sensitive compared with visible and IR threshold tests. Cloud cover obtained by the whole method is finally compared with that resulting from the visible and IR histogram analysis procedure of Phulpin et al. This comparison indicates a high reliability of the proposed method.

Description: The diets of 20 species of smaller Odontoceti were investigated. The material was collected along the southern African coast between 1966 and 1990 and included 158 strandings, 29 animals killed incidentally and 49 animals caught under permit. In total, 57 species in 34 families of fish and 89 species in 24 families of cephalopods were identified from remains in the 236 stomachs investigated. Most Odontoceti fed on commercially unexploited cephalopods and fish, or on fish below commercially utilized sizes. However, the average sizes of anchovy and pilchard eaten by Delphinus delphis and Lagenorhynchus obscurus were larger than the sizes most frequently taken commercially. The species composition of the prey items reflected the onshore-offshore distribution (and possibly the foraging depths) of different Odontoceti. Tursiops truncatus and Cephalorhynchus heavisidii were closest to shore and D. delphis and L. obscurus over the continental shelf. The rest were distributed around the shelf-edge and just off the edge. A comparison of the stomach contents of stranded and non-stranded D. delphis, L. obscurus and C. heavisidii demonstrated that results from stranded animals are biased.

Description: The community of benthic organisms in the lower zone of a rocky shore at Praia Rasa, Brazil is distinctly patchy in structure. We examined the hypothesis that two types of patch (a. red algal turf and b. colonial coelenterate) represent different temporal stages in the same successional trajectory. We made observations on a) the stability of patch boundaries, b) successional sequence in experimental clearings within both patch types and c) species composition through time in undisturbed patches. In most cases, the coelenterate overgrew the algae at the patch boundaries, thus showing a competitive asymmetry. In the successional sequence, diatoms were followed by ulvoid species. Thereafter, within clearings in the algal patches, a red algal turf was once more established over one year. In contrast, the mid successional period in clearings within the coelenterate patch was characterized by very low cover of sessile organisms. Colonization by red algal turfs and by the coelenterate colony is largely dependent on vegetative spread. Thus later succession is not predictable on the basis of time alone. Supply-side processes are clearly of equal importance. Therefore it cannot be stated without qualification that patches of red algal turfs and colonial coelenterate at Praia Rasa are part of the same successional sequence.

Description: A vertical mixing model was applied to a location off the west coast of the South Island, New Zealand, with the aim of simulating the seasonal cycle of temperature and mixed layer depth in the region. Observed weather data for 1973–89 were used to drive the model. Model results for sea temperature and mixed layer depth were compared to measurements from ships, moored temperature sensors, and satellites. The main features of the variations in temperature and mixed layer depth can be explained by the local meteorological forcing and vertical mixing, together with a general southward flow in the study area. Superimposed are short‐term variations which are obviously related to variable currents and the associated horizontal heat transport.

Description: Specimens of Siboglinum poseidon were collected by box coring and studied together with their undisturbed habitat. Occupied tubes occur in depse aggregations beneath the sediment surface directly at methane seep sites. Fertilized eggs develop into small larvae within the anterior transparent region of the tube. The oldest larvae observed in tubes measure c. 370 µm in length. It is concluded that released larvae develop in the sediment in the oxygenated top layer. Three tube types have been found: 1, the larval envelope; 2, the juvenile, transparent tube and 3, the ringed, adult tube. The smallest specimens recovered from the sediment measure c. 2 mm. They are complete with a tentacle, pyriform glands, bacteriocytes and juvenile opisthosoma. Some larvae were reared under laboratory conditions for 10 weeks. At that stage red blood becomes visible and a small tentacular bud is formed dorsally.

Description: Kanechlor-300, -400, -500 and -600, Phenoclor DP-3, -4, -5 and -6 and Sovol mixtures were analyzed for their chlorobiphenyl (CB) composition using high-resolution one-dimensional and multidimensional gas chromatography-electron capture detection (MDGC-ECD) techniques. The congener patterns of tested Kanechlor and Phenoclor mixtures resembled Aroclor 1016, 1242, 1254 and 1260. However, differences in the percentage contribution of minor constituents were noticed among these mixtures, which could be due to variations in the boiling-point fractionation of these commercial products. CB pattern of Sovol was different from the rest of the mixtures tested. It showed a composition in between ca. 30%, 40%, 50% and 60% overall chlorine levels. MDGC-ECD study showed the presence of hitherto unnoticed non-CB compounds coeluting with CBs in some commercial PCBs. The use of these mixtures as quantitation standards should be considered with caution. CB patterns of Sovol and a water extract of the Gulf of Finland matched closely, indicating a point source contamination to these waters.

Description: A series of field experiments has been made to determine the occurrence of small-scale surface motions that might enhance gas exchange by surface renewal. Out of 93 runs under natural conditions on open bodies of water, only 19 gave no indication of surface streaming within a few seconds. The data cover the wind speed range up to about 6 ms-1. Above 2 or 3 ms-1, predominately line structures were observed. This points to an important r6le of surface renewal in gas exchange.

Description: The North Pacific is a sea area of primary interest to Russia, which inherited key strategic interests of the former Soviet Union. But the North Pacific has also become an area of increasing resource exploitation activity. These factors lead to an even more active involvement in regional political relations. The article touches on a number of most urgent, controversial, and still unsolved issues faced today by the Russian Federation. The author concentrates on two major problems: the issue of international fisheries in the so‐called doughnut hole (located in the central Bering Sea), and the highly controversial questions of marine spaces delimitation between Russia on one side and Japan (which raises a more general political question of sovereignty over the four southernmost islands of the Kuril chain) and the United States on the other.

Description: Results are presented following a long-term study of the diet of the Cape gannet Morus capensis at Bird Island, Algoa Bay, examining 4 178 regurgitations representing 36 351 prey items collected during 12 breeding cycles from April 1979 to March 1991. In all, 32 teleost and two cephalopod species were recorded. The pelagic shoaling pilchard Sardinops ocellatus, anchovy Engraulis capensis and saury Scomberesox saurus scombroides were identified as the main prey species. The diet composition showed marked interannual fluctuations during the sampling period, which appear to be related to changes in the abundance of the main prey species. The relative abundance of pilchard, anchovy and saury was also found to change intra-annually, the first two species occurring more frequently in the diet during the breeding season and saury dominating the diet in the non-breeding season. These changes are thought to originate from temporal variation in the oceanographic regime within the foraging range of the gannets.

Description: Six species of skates were trawled commonly on the continental shelf off the Southern Cape during routine surveys of demersal fish between 1986 and 1990. Raja miraletus is a small skate found principally in shallow (〈50 m) water that feeds mainly on small crustaceans, such as mysids and macrurans. The large Raja alba occurs over most of the continental shelf, is a piscivore throughout its life and preys heavily on flatfish, especially Cynoglossus zanzibarensis. R. cf. clavata is ubiquitous on the shelf but most abundant between 50 and 150 m deep. Feeding predominantly on crustaceans, this skate switches from carids, penaeids and mysids when small to brachyurans and small benthic fish when larger. R. pullopunctata is found over a similar depth range but attains a much larger size. It eats small mysids and macrurans when small, but brachyurans and fish become more important in the diet with increasing size of the predator. R. wallacei is most commonly taken at depths of 80–〉200 m, feeds initially on small crustaceans, but switches to fish, including eels, as it grows. The small Cruriraja parcomaculata is found at the edge of the continental shelf and over the upper slope; it preys on small crustaceans, including mysids, isopods and macrurans. The distribution pattern of the skates and their prey suggest overlap in prey taken, the overlap being greatest in those species which feed on crustaceans. The large biomass of skates in the area suggests that they are an important component of the demersal faunal assemblage of the continental shelf there, and also that they may have a significant impact on the benthic fauna.