Puerto Deseado Research Articles

New records of demosponges (Porifera) from the South Orkney Islands (Antarctica) with a checklist for the region.

The South Orkney Islands (SOI) is a poorly studied Antarctic archipelago located in the Scotia Arc. In this study, we added 25 Demospongiae species to the SOI known sponge richness, which was previously represented by only 16 species. Of these, 22 species represent new records for SOI region, although they were previously recorded from other Antarctic sectors. Samples were collected during two Argentinean Antarctic Research Cruises onboard RV Puerto Deseado. The most frequently collected species were Artemisina apollinis, Iophon gaussi, I. unicorne, Lissodendoryx (E.) ramilobosa, Myxodoryx hanitschi and Tedania (T.) tantula. Data and illustrations of some rare or uncommon species are provided: Iophon gaussi, Lissodendoryx (E.) anacantha, Microxina charcoti, Raspailia (H.) hentscheli, Haliclona spongiosissima, Haliclona (G.) cf. cucurbitiformis. Although the present results increase substantially the previously known information on sponge species, this is still an underestimation of total richness because certain orders (Tetractinellida, Suberitida, Biemnida, Polymastiida) and classes were not studied during the current investigation, although previous records were included.

Variación estacional del contenido de lípidos en Tigriopus californicus (Backer) (Copépoda, harpacticoida)

Seasonal variations of the body weight, water content and lipid amount in adult individuals of Tigriopus californicus (Backer) from peninsula Foca, Puerto Deseado (Sta. Cruz) were studied. Correlations among them were found.
 Experiences were realized during 1978 and 1979, using 100 individuals as optimun number for each test, taking them at random.
 Maximun values for body weight and for water content are observed during the spring and minimun values at the end of the summer. In relation to the lipid percentage (based in the dry weight) it reaches its maximum values during the spring, existing an inverse correlation with the former parameters.
 It was also proved the influence of the ovigerous female on the lipid content of the adult population during 1978.
 Maximun values were obtained in summer and minimum ones in spring, according to the population movement of the species (Lombardo y Pallares, 1981).
 Complementary data of nitrogen and protein percentages (based in the dry weight) during 1979 were given. In addition to the lipid and protein percentage, the calorific contenta owing to them are expressed in Kcal/g of dry weight.

Revision of the genus Oxyarcturus (Isopoda, Valvifera, Antarcturidae), with a description of a new deep-sea species from Argentina

A new antarcturid isopod, Oxyarcturus holoacanthussp. nov., is fully described based on seven specimens collected in the Mar del Plata submarine canyon at 2950 m depth, during the “Talud Continental III” expedition on board the Argentinian RV “Puerto Deseado”. Oxyarcturus holoacanthussp. nov. is closely related to O. spinosus (Beddard, 1886), from which it can be distinguished by the body spine pattern. The penial plate, a novel character for the genus Oxyarcturus, as well as for the family Antarcturidae, is described in detail. The species O. dubius (Kussakin, 1967) and O. beliaevi (Kussakin, 1967) are considered as incertae sedis until further morphological and molecular data can clarify their taxonomic position. An update of the geographic and bathymetric records of the genus Oxyarcturus is provided.

Southern coastal system of the San Jorge Gulf during spring

The San Jorge Gulf was declared an area of national economic, commercial, conservation and diversity interest. To contribute to its study, the southern coastal sector of the gulf was characterised in physical and chemical parameters in spring campaigns (November 2016 and 2017). Samples were taken on board the oceanographic vessel Puerto Deseado in three perpendicular to the coast transects and another one to the southeast of the gulf, which crosses a thermohaline front. The perpendicular to the coast transects showed a similar pattern of distribution of physical and chemical properties in the water column. At nearshore stations, the water column was homogeneous and the nutrient concentrations between the surface and bottom layers were similar. At offshore stations, the water column was stratified and the nutrient concentrations were higher near the bottom than at surface. In 2016, a wind induced upwelling front was observed in the southwest of the gulf. Both sides of the thermohaline front did not show significant chemical differences. Throughout the study area, silicic acid and nitrate limited primary production. Satellite chlorophyll-a data and fluorescence profiles showed that the southern sector of the gulf has a high biomass of phytoplankton during November. We conclude that the southern sector of the SJG has different features depending on the external forcing caused by the front. The presence of fronts stimulates the growth of phytoplankton biomass through the injection of nutrients from the homogeneous part to the stratified sector. This would affect phytoplankton community and, thus, the productivity of the system.

Parasitological survey of coastal birds from the Magellanic coast, Southwestern Atlantic Ocean

Ecto and endoparasites of four species of coastal birds, Haematopus ater, Larus dominicanus, Leucophaeus scoresbii (Charadriiformes), and Lophonetta specularioides (Anseriformes), are reported from Puerto Deseado on the Patagonian coast, Argentina. Only H. ater was infested with lice (Phthiraptera), belonging to 2 species (Ischnocera, Amblycera). A total of 19 helminth species were found parasitizing the coastal birds studied: 4 cestodes (1 Tetrabothriidae, 3 Cyclophyllidea); 11 trematodes (2 Gymnophallidae, 3 Microphallidae, 2 Notocotylidae, 1 Philophthalmidae, 2 Renicolidae, 1 Schistosomatidae); 3 nematodes (1 Anisakidae, 2 Acuariidae); and 1 acanthocephalan (Polymorphidae). Although some isolated records have been previously reported for these birds, the present work provides a parasitofauna study for H. ater, L. scoresbii, and L. specularioides for the first time. Endoparasites reflected the feeding habits of the birds; the parasite assemblage of L. dominicanus was the richest, indicating their wide prey spectrum and the diversity of the habitats frequented. A great species richness of trematodes, whose life cycles are partially known, suggests that L. specularioides feeds upon crustaceans and small bivalves. The blackish oystercatcher H. ater preys upon the limpet Nacella magellanica which hosts two larval trematodes corresponding to the adults found parasitizing it.

Urban dog attacks on Magellanic Penguins in a protected area


 
 
 The presence of unsupervised dogs in urban areas close to sites of high natural value can have negative effects on wildlife. On the Patagonian coast, where cities are often surrounded by natural environments, this problem may affect seabird colonies. Two islands with Magellanic Penguin (Spheniscus magellanicus) colonies belonging to a protected area neighboring Puerto Deseado, Santa Cruz, suffered attacks by unsupervised dogs. In 2016 and 2022, several dogs reached these islands during low tides and attacked penguins. At Isla Quiroga, 421 penguins died in 2016, causing a decrease of 21.4% in its population. At Isla Quinta, 30 individuals died in 2016 and 32 in 2022, representing in both cases almost 100% of the colony. These are the first records of attacks since we are monitoring these colonies (>30 years). The growth of coastal cities is constant and these events could become more frequent and affect more species of seabirds. The control of unsupervised dogs in natural areas near coastal developments is a challenge that government entities should respond to in the short term.
 
 

Archaeological research and heritage management of a British shipwreck in Argentina - the legacy of HMS Swift (1770)

SUMMARY HMS Swift was a British sloop of war which sank in Patagonia - South Atlantic Ocean - in 1770. The wrecksite was discovered in 1982 by local divers from Puerto Deseado, Santa Cruz Province, Argentina, and this find originated the development of underwater archaeology in the country. The article presents a comprehensive review of the various research strands addressed throughout many years, and it also reflects on the legacy that the site and the project represents for topics other than archaeology, such as heritage management, museology, and cultural industries.

P465 Aspergillosis in free-ranging Magellanic penguins

Poster session 3, September 23, 2022, 12:30 PM - 1:30 PMAspergillosis is an opportunistic fungal disease caused by the Aspergillus genus, mostly by Aspergillus section Fumigati. Captive Magellanic penguins are vulnerable to Aspergillus infection, being this mycosis a limiting factor during the process of rehabilitation with a mortality rate of around 50%.ObjectivesGiving the scarce data regarding the occurrence of aspergillosis in non-captive penguins, we aimed to evaluate the proportional mortality by aspergillosis in free-ranging Magellanic penguins during their migration and reproductive season.MethodsCarcasses of Magellanic penguins were collected from the Southern coast of Brazil between June 2017 and October 2019 between Barra do Chui beach (Southern RS, Brazil - 33°44'19.9‘S 53°21'56.3’W) and the isthmus with the Lagoa do Peixe (Southern RS, Brazil - 31°26' S, 51°10' W 31°14'S, 50°54'W). In addition, in January 2019, penguins found dead in the reproducing colony in four islands localized in Puerto Deseado City (Santa Cruz, Patagonian, Argentina - 47°45′00″S 65°55′00″W) were collected. All animals were necropsied, and macroscopic alterations were observed. Samples of macroscopic lesions and/or respiratory systems were collected for histopathology and mycological culture. Only proven aspergillosis cases, defined by suggestive lesions at necropsy, associated with hyaline, septate, and 45° branched hyphae in histopathological slides and isolation of Aspergillus sp. in the culture were computed. Fungal isolates were identified by molecular techniques.ResultsA total of 98 Magellanic penguins were included in our study, being 80 recovered on the Southern RS beach, and 18 from the Patagonian colony. Two penguins collected in Southern Brazil were diagnosed with aspergillosis, both juveniles, one showing nodules in the lung parenchyma, and the other nodules and fungal colonies at the lung and air sac, resulting in a proportionate mortality rate of 2.5%. Both isolates were identified as A. fumigatus sensu stricto. Regarding the carcasses collected from the reproductive colony (Patagonian islands), no penguin had anatomopathological or mycological evidence of aspergillosis.ConclusionGiven the already known importance of aspergillosis in seabirds undergoing rehabilitation, these data suggest that penguins may already arrive in these centers infected by Aspergillus spp. The absence of aspergillosis cases in the reproductive period could be attributed to the low number of carcasses included. Our study is an initial step to demonstrate aspergillosis as one of the causes of mortality also in free-living penguins, especially during the migration process, instigating more studies, in other routes of migration, as well as in reproductive colonies.

Reproductive biology of the brooding feather star Phrixometra nutrix, from the southwestern Atlantic

Reproduction of the brooding feather star Phrixometra nutrix was studied from the deep southwestern Atlantic Ocean. Samples were collected using dredge trawlers and fishing nets on board the B/O Puerto Deseado, between 91 and 512 m depth. Reproductive biology was studied using modern optical techniques including histology and scanning electron microscopy. Here we present the first record of genital papillae for class Crinoidea. Genital papillae have been reported in all extant echinoderm classes except for Crinoidea. In addition, a high proportion (16%) of hermaphroditic specimens was found in the analyzed samples. Finally, cystidean and pentacrinoid stages were found inside the marsupium of Phrixometra nutrix. It is expected that this work will enable further discoveries of crinoid reproductive biology considering the ecological and phylogenetic importance of brooding crinoids.

Antifouling Diterpenoids from the Sponge Dendrilla antarctica.

Two nor-diterpenes, 9,11-dihydrogracilin A (1) and the previously unreported 9,11-dihydrogracillinone A (2), were isolated from the sponge Dendrilla antarctica. The sponge was collected by trawling at a depth of 49 m, from the research vessel Puerto Deseado, near the coast of Tierra del Fuego, farther north than the reported habitat for this species. Since these compounds were particularly abundant and the sponge was free from epibionts, both 1 and 2 were included in soluble-matrix paints and tested for antifouling activity in the ocean. The results obtained from these experiments clearly indicated a potent antifouling activity for both compounds against a variety of colonizing organisms, and established a probable role as natural antifoulants for these abundant secondary metabolites and other structurally related compounds previously isolated from Dendrilla spp.

Thalia longicauda(Quoy and Gaimard) from the south-western Atlantic Ocean (31°S–38°S): distribution and population structure

AbstractAlthough the salp Thalia longicauda is common in the southern hemisphere, there is little information on its biology and ecology. Our study aimed to describe the morphology of the development of solitaries and aggregates and to determine the developmental stages, length distribution and population structure of this species. Plankton samples were collected by the R/V ARA “Puerto Deseado” from 31°55′S to 38°08′S (October 2013). Thalia longicauda was present at 50% of the stations, ranging between 1.21 and 2970 ind. 1000 m−3. Solitaries and aggregates represented 53.76 and 46.24%, respectively. We described the growth of the blastogenic stolon and the formation of blocks of aggregates buds. Each solitary may produce at least three blocks with a total of 36–86 aggregate buds. The relationship between total number of aggregate buds (y) and total length of the solitary (x) was y = 3.321x − 13.489. We characterized six developmental stages for solitaries and four for aggregates. The juvenile/mature ratio of solitaries and aggregates suggested that the population was actively reproducing both sexually and asexually. Based on seawater temperature and salinity data, T. longicauda may be considered as a temperate species inhabiting the southern range of subtropical waters and the northern range of sub-Antarctic waters.

A new species of Pseudione sensu lato (Isopoda: Bopyridae) on a squat lobster host from the deep South-West Atlantic

A new bopyrid, Pseudione chiesai n. sp., is herein described based on an ovigerous female and an adult male found in the right branchial chamber on a specimen of Munida spinosa Henderson, 1885. This parasite was collected in the Mar del Plata submarine canyon at 819 m depth during the expedition Talud Continental I carried out by the Argentine RV Puerto Deseado in 2012. P. chiesai n. sp. belongs to the Pseudione crels group sensu Bourdon (1972, 1976), which currently contains seven species, all of which have galatheoid crabs as hosts. P. chiesai n. sp. can be separated from the other species in the Pseudione crels group by the following combination of characters: (1) both sides of the body convex, (2) frontal lamina with a few, shallow indentations, (3) coxal plates 14 and tergal projections 14 with distinct irregular margins, mainly on the right side, (4) pereomeres 57 with single/branched lateral digitations, (5) maxilliped palp well-developed and setose, and (6) pleon with lateral plates 15 distally rounded and directed laterally. The taxonomic position of this new species is briefly discussed.

Relevance of sporadic upwelling events on primary productivity: The key role of nitrogen in a gulf of SW Atlantic Ocean

In order to assess the relevance of sporadic upwelling events on primary productivity, the availability of nitrogen (N) sources and their uptake by phytoplankton were studied. Incubations of 15N-enriched samples were performed at 3 depths in 12 stations in San Jorge Gulf (SJG, Patagonia Argentina) aboard of the R/V “Puerto Deseado” during November 2016. Additional coastal stations were sampled to analyze the upwelling event. The total uptake of N sources (ρNO3- + ρNH4+) was higher on the surface than in the deep layer. The ρNO3- by phytoplankton doubled that of ρNH4+ suggesting SJG acted as a CO2 sink during the period studied. However, NH4+ played an important role in maintaining primary productivity where NO3− was low. In most stations, phytoplankton showed a preference for the uptake of the less available N source, likely resulting from adaptation to low nutrient concentrations. However, in the southwestern sector of the gulf, where a wind-induced upwelling occurred, phytoplankton preferred to uptake NO3−, this being the most abundant N source. As a consequence, the integrated primary productivity in the water column of that sector was high. Results suggest that such high productivity was governed by the optimal relationship between the preference and availability of N, established by the presence of elevated NO3− and low NH4+ ambient concentration. This would be a physiological process regardless of community composition. The new primary productivity generated by upwelling events could be key to feeding the biological resources of the gulf.

Potencialidad de Puerto Deseado y Camarones (Argentina) como destinos de cruceros a partir de sus competencias territoriales

El turismo de cruceros está comúnmente asociado a una práctica exógenamente determinada. Sin embargo, como práctica social, se emplaza en un espacio cargado de connotaciones sociales y culturales; haciendo uso de un territorio construido socialmente. Desde esta mirada la decisión de optar por este tipo de actividad es tomada teniendo en cuenta un conjunto de elementos que va más allá de las características del buque. Los territorios en cuestión deben poseer una serie de condiciones que resulten favorables para su competitividad, fundamentalmente asociadas a la presencia de recursos naturales y culturales que conforman la oferta de sitios potenciales de visita y la prestación de servicios. Estos factores forman parte de las competencias territoriales que poseen los destinos y pueden actuar como elementos que favorezcan y potencien su inserción en el turismo de cruceros. Puerto Deseado y Camarones, dos puertos de la Patagonia argentina, han mostrado interés por esta actividad surgiendo el interrogante respecto a las competencias territoriales que poseen para el desarrollo del turismo de cruceros. El trabajo optó por un enfoque cualitativo, apoyado en técnicas cuantitativas desarrollado durante la temporada de verano 2017-2018 y consistió en el relevamiento y análisis de diferentes componentes territoriales complementado con la opinión de informantes clave. Los resultados obtenidos reflejan la potencialidad que poseen ambas localidades en términos de sitios de visita y planta turística destacándose que, si bien cuentan con un conjunto de componentes territoriales que los posicionarían competitivamente en el mercado de cruceros, también es necesario fortalecer otros.

The North Atlantic Conoidean Gastropod Theta lyronuclea (Raphitomidae) in Deep-Waters of the Southwestern Atlantic

Theta lyronuclea (Clarke, 1959), a North Atlantic deep-water species, is recorded for the first time from the southwestern Atlantic. This constitutes the first record of the genus and the second mention of the family Raphitomidae off Argentina. The samples were collected in the Mar del Plata Submarine Canyon on the Argentine Continental slope on board the R/V Puerto Deseado at 2,934 m depth in September 2013. Photographs of radulae, penises, and details of the ornamentation of the protoconch are provided. Detailed comparison of the specimens collected with the type material and several lots from northern Atlantic localities confirmed the identification.

Biodiversity of Isopoda and Cumacea (Peracarida, Crustacea) from the Marine Protected Area Namuncurá-Burdwood Bank, South-West Atlantic

Burdwood Bank is a shallow seamount located south of the Malvinas (Falkland) Islands and east of Tierra del Fuego. In 2013, the area down to 200 m depth of this bank was declared the first open-sea (non-coastal) Marine Protected Area (MPA) in Argentina, and named “Namuncurá” (MPAN-BB). The present study aimed to evaluate the biodiversity of the isopods and cumaceans from the MPAN-BB. The studied material was collected on board the Argentine RV Puerto Deseado during the Campaña Antártica de Verano 2013. Three stations from the MPAN-BB, respectively, located in the core, buffer, and transition sectors, were sampled. A total of 17,076 specimens were sorted and 70 taxa distributed in 22 families were identified. Thirty-five new records of distribution and eight species most probably new to science are herein reported. Paramunnidae and Diastylidae were the most abundant and diverse families among isopods and cumaceans, respectively. Our records, together with those obtained from the literature, make a total of 55 nominal species so far known from Burdwood Bank. Except for one nominal species, which had been reported from the Puerto Rico Trench and the Argentine Basin, all the remaining species had also been recorded from other localities within the Magellan Region. In contrast, only nine out of the 55 nominal species had also been reported from the Antarctic Peninsula and/or Scotia Arc. This indicates that the isopods and cumaceans from Burdwood Bank are typically Magellanic, and there is little correspondence between this fauna and that from the Antarctic Peninsula and Scotia Arc.

Brooding in the deep-sea sea anemone Actinostola crassicornis (Hertwig, 1882) (Cnidaria: Anthozoa: Actiniaria) from the southwestern Atlantic Ocean

Fil: Lauretta, Daniel Marcelo. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales Bernardino Rivadavia; Argentina

Last Interglacial sea-level highstand deduced from notches and inner margins of marine terraces at Puerto Deseado, Santa Cruz Province, Argentina

Fil: Bini, Monica. Istituto Nazionale di Geofisica e Vulcanologia; Italia. Universita degli Studi di Pisa; Italia

A potential zoonotic parasite, the digenean Gymnophalloides nacellae, on the Magellanic coast in the Southwestern Atlantic Ocean: its life cycle and geographical distribution

This is an integrative study of a potential zoonotic digenean from the Magellanic Southwestern Atlantic coast. The life cycle of the gymnophallid Gymnophalloides nacellae Cremonte, Pina, Gilardoni, Rodrigues, Chai and Ituarte, 2013 (Digenea) at the type locality, Puerto Deseado (47° 45′ S, 65° 51′ W), Santa Cruz province, was elucidated. This digenean uses the upper subtidal clam Gaimardia trapesina (Lamarck) (Gaimardiidae), which lives on the fronds of the giant kelp, as first intermediate host. A very short-stem furcocercous cercaria emerges and enters the limpets, Nacella magellanica (Gmelin) and N. deaurata (Gmelin) (Nacellidae), which live in the lower rocky intertidal zone. The unencysted metacercariae inhabit the extrapallial space of the limpet at high prevalences and intensities of infection. When the black oystercatcher Haematopus ater Vieillot and Oudart (Charadriidae) preys upon it, it becomes infected, acting as the definitive host. This parasite seems to exhibit a high specificity for their first and second intermediate hosts. Its geographical distribution is from 47 to 55° S in Patagonia, and it is restricted to those sites where the giant kelp reaches to lower intertidal and upper subtidal zones where the limpets are present. Gymnophalloides seoi Lee, Chai and Hong, 1993, a parasite of the Pacific oyster Magallana gigas (Thunberg) (Ostreidae), causes a zoonotic disease in Korea; thus, G. nacellae represent a risk of being a zoonotic parasite if infected limpets are consumed.

Benthic communities in the Southwest Atlantic Ocean: Conservation value of animal forests at the Burdwood Bank slope

Abstract The characterization of benthic communities at the Burdwood Bank slope (≥200 m depth) is provided, comprising data from the marine protected area (MPA) Namuncurá II (created in December 2018), as well as from some deep bathyal surrounding areas in the Southwest Atlantic Ocean. This information was acquired during two research cruises with RV Puerto Deseado (Argentina) during 2016 and 2017. Marine animal forests were detected in the study area: coral gardens, mainly composed of alcyonaceans, were detected in the south and west of Burdwood Bank (MPA Namuncurá II) and neighbouring areas, whereas pennatulacean aggregations were detected in the north‐west of the plateau. The three‐dimensional structures of live but also dead corals provide substrate and refuge to many associated species. Benthic communities dominated by sponges were also recorded between 200 and 300 m in depth. Six sites that meet the characteristics of vulnerable marine ecosystems (VMEs) are reported. Conservation strategies applied to scarcely known austral Argentinean waters led to the establishment of a pioneer MPA (Namuncurá I). Following the management plan that aimed to establish the biodiversity of Namuncurá I and neighbouring areas, the area of protection has now been enlarged to include the southern slope of the bank (currently Namuncurá II), where marine animal forests were detected, at depths below 200 m. The data presented here provide empirical evidence to support the conservation value of the region.