Publications
Bioarqueología de la violencia interétnica. Un modelo para abordar el ataque indígena al Fuerte San José (Península de Valdés, Chubut, República Argentina)
A novel bioarchaeological model has been developed to characterize the material traces of a 19th-century indigenous attack on the Spanish Fuerte San José in Península Valdés, Argentina. This approach integrates historical documentation, ethnohistoric data, and bioarchaeological evidence from similar conflict scenarios to derive specific expectations for identifying and analyzing skeletal remains linked to the 'malón' of 1810. The model aims to distinguish these violent events from other causes of mortality in the enclave, contributing to the emerging field of bioarchaeology of violence. By synthesizing disparate data sources—including taphonomic processes and osteological records—the study provides a framework for future investigations into interethnic conflict during the colonial period.
Carbon and nitrogen stocks in sediment at Península Valdés Biosphere Reserve: novel insights into the potential contribution of large marine vertebrates to carbon sequestration
Research at Península Valdés Biosphere Reserve reveals that large marine vertebrates, such as South American sea lions and southern right whales, contribute to coastal carbon sequestration through their organic carbon (OC) stocks. Sediment analysis across three locations showed OC storage ranging from 140 to 317 Mg ha-1, with a notable proportion (0.8–6.8% dry weight) of OC originating from these vertebrates. While salt marshes and terrestrial plants were the primary carbon sources, this study provides novel evidence that large marine vertebrates act as significant OC vectors in coastal systems, offering new insights into their role in blue carbon dynamics.
Dissolved organic matter dynamics in a whale-dominated coastal system: Insights from Península Valdés, Argentina
Research at Península Valdés, Argentina, reveals that large marine mammals, particularly whales, significantly influence dissolved organic matter (DOM) dynamics in coastal ecosystems. The study found that the carbon isotopic signal of dissolved organic carbon (DOC) was predominantly derived from whale and phytoplankton sources, suggesting a 'whale pump' mechanism where whales contribute both labile and recalcitrant DOC to coastal habitats. Microbial overconsumption during the whale calving season increased the DOC:DON ratio, indicating higher refractoriness of DOC. Bioavailable DOC ranged from 18.6% to 52.7% of the total DOC pool, while recalcitrant DOC concentrations averaged 200 ± 19 μM in non-whale seasons and 180 ± 7 μM during whale seasons. These findings underscore the role of whales as vectors for DOM, modulating its dynamics and potentially impacting coastal ecosystem health.
Influence of water temperature, body size, condition and gull-inflicted lesions on heat loss in southern right whales in Península Valdés, Argentina
Southern right whales (Eubalaena australis) migrating from cold feeding grounds to warmer breeding grounds in Península Valdés, Argentina, experience reduced heat loss during early lactation by 26%, but this migration offers limited thermoenergetic benefits overall. The study found that body condition is a critical regulator of heat loss, with poor condition increasing heat loss beyond field metabolic rate (FMR), threatening survival. Gull-inflicted lesions significantly increase heat loss in small or poorly conditioned calves but have no effect on larger or better-conditioned whales. Researchers used unmanned aerial vehicle photogrammetry to measure body size, volume, and condition, combined with blubber-mass modeling and necropsy data, to estimate sensible and respiratory heat loss. This work highlights the complex interplay between environmental factors, body condition, and external stressors in whale thermoregulation.
Do whale‐watching vessels affect the distribution of southern right whales (Eubalaena australis) in Península Valdés, Chubut, Argentina?: Using the COVID ‐19 lockdown as a case study
Southern right whales (Eubalaena australis) in Península Valdés, Argentina, showed significant shifts in their distribution during the COVID-19 lockdown, suggesting that whale-watching vessel activity may influence their behavior. The study analyzed data from 2019 (pre-pandemic), 2020 (during lockdown with minimal vessel traffic), and 2021 (post-lockdown) to compare core and home ranges of whales, including mother-calf pairs. Results indicated that the absence of whale-watching vessels in 2020 led to increased overlap in core areas, particularly for mother-calf pairs, implying that human activity may alter their spatial patterns. The research highlights the potential ecological impact of tourism on marine mammals and underscores the importance of monitoring such interactions.
Epidemiological data of an influenza A/H5N1 outbreak in elephant seals in Argentina indicates mammal-to-mammal transmission
A massive outbreak of H5N1 high pathogenicity avian influenza virus (HPAI) in southern elephant seals at Península Valdés, Argentina, in October 2023, provides compelling evidence for mammal-to-mammal transmission. Genomic analysis revealed that viruses from pinnipeds and terns form a distinct clade with marine mammal viruses across South America, sharing identical mammalian adaptation mutations. This suggests multinational transmission of H5N1 in mammals, with occasional spillover to birds. The study highlights the virus's increasing evolutionary flexibility and potential global implications for wildlife, humans, and livestock.
Foraging dives of southern right whales (Eubalaena australis) in relation to larger zooplankton size prey availability in Golfo Nuevo, Península Valdés, Argentina
Southern right whales (Eubalaena australis) in Golfo Nuevo, Península Valdés, Argentina, exhibit daytime foraging dives to exploit high concentrations of larger zooplankton near the seafloor, a behavior not previously documented. Using suction-cup-attached video-imaging tags (CRITTERCAMs), researchers tracked eight whales, observing feeding events during dives averaging 6 minutes and 45 seconds. Zooplankton samples revealed that euphausiids dominated deeper layers with five times higher biomass than subsurface copepods, suggesting SRWs target these prey during their ascent. This study provides critical insights into the foraging strategies of SRWs in a recognized calving ground, highlighting their adaptability to exploit deep-sea resources.
Massive outbreak of Influenza A H5N1 in elephant seals at Península Valdés, Argentina: increased evidence for mammal-to-mammal transmission
A massive outbreak of high pathogenicity avian influenza (HPAI) H5N1 in southern elephant seals at Península Valdés, Argentina, has provided unprecedented evidence for mammal-to-mammal transmission. The outbreak, which resulted in the death of approximately 17,000 individuals—disproportionately affecting seal pups—and disrupted social and breeding structures, was linked to frequent interactions with sea lions and scavenging by seagulls. Genomic characterization revealed that viruses from pinnipeds and terns in Argentina form a distinct clade with marine mammal viruses from Peru, Chile, and Brazil, sharing an identical set of mammalian adaptation mutations also found in the terns. This multinational transmission of H5N1 viruses in mammals is the first observed globally, suggesting increased evolutionary flexibility and potential global implications for wildlife, humans, and livestock.
Taphonomic Analysis of an Articulated Baleen Whale (Cetacea; Mysticeti) from Upper Miocene Inner Shelf Deposits of Península Valdés, Patagonia, Argentina
A remarkably well-preserved, almost fully articulated baleen whale skeleton from the Late Miocene of Península Valdés, Argentina, offers unprecedented insights into taphonomic processes and paleoenvironmental conditions. This specimen, one of the most complete balaenid skeletons known globally, reveals a brief biostratinomic phase characterized by initial decomposition at sea, gas accumulation leading to reorientation, sinking in a ventral-up position on the inner shelf, and lateral re-orientation due to physical and biological processes. The high degree of articulation and association of skeletal elements suggests no lateral transport or refloating, indicating rapid burial under low-energy conditions with normal marine oxygenation and salinity. This study integrates taxonomic, sedimentological, stratigraphic, and ichnological analyses to reconstruct the complex taphonomic history and paleoenvironmental context of this exceptional fossil.
Miocene dinoflagellate cyst biostratigraphy of the Península Valdés, Patagonia, Argentina
Researchers have identified eight key diagnostic events of dinoflagellate cyst taxa from the Península Valdés, Argentina, providing the first detailed biostratigraphic framework for the region. These events allowed the subdivision of sedimentary successions into Early to Middle Miocene and Late Miocene periods, offering new insights into the paleoenvironmental conditions of the area during this time. The study analyzed samples from the upper part (60–585 m) of the YPF.Ch. PV. es-1 borehole, focusing on taxa such as Spiniferites/Achomosphaera spp., Reticulatosphaera actinocoronata, and others. Comparisons with Northern Hemisphere dinoflagellate cyst records revealed a strong similarity, except for Hystrichokolpoma rigaudiae, which may indicate local paleoenvironmental variations.
Primeros resultados sobre la percepción social del patrimonio cultural de la península Valdés (Patagonia), según sus visitantes
A study on the Península Valdés, Patagonia, reveals that the focus on conservation and tourism has led to the marginalization of its cultural heritage, both material and immaterial. The research, based on a 2020 survey of visitors, found that the emphasis on natural conservation and tourism planning has resulted in a distorted perception of the site's past, overshadowing its rich cultural heritage. This imbalance not only invisibilizes the historical significance but also undervalues the cultural content for tourists, providing them with a limited and biased perspective.
Spatial and temporal dynamics of whalewatching in Península Valdés, Patagonia, Argentina
Whalewatching in Península Valdés, Patagonia, Argentina, exhibits distinct spatial and temporal patterns that can enhance recreational experiences while supporting conservation efforts. The study found that sightings near Puerto Pirámides shift farther from the coast as the whale season progresses, with early trips focusing on varied groups like solitary whales, mating pairs, and mothers with calves, while later trips predominantly feature mother-calf pairs—the last to leave the area. This pattern suggests potential for tailored whalewatching experiences, balancing economic benefits with conservation goals, given that both gulfs of Península Valdés are critical calving grounds for southern right whales (Eubalaena australis). The research analyzed 1,816 trips over six reproductive seasons (2005–2008 and 2012–2013), tracking stopovers ('sightings') to identify these dynamics. Properly applied regulations could further improve conservation outcomes in this globally significant site.
Red Knot ( Calidris canutus rufa ) site fidelity at Península Valdés, Argentina
Red Knots (Calidris canutus rufa), long-distance migratory shorebirds, exhibit strong site fidelity to Península Valdés, Argentina, during their northward migration (March–May). A standardized Site Fidelity Index revealed that these birds are most loyal to playas Blancas, Fracasso, and Colombo, with higher fidelity observed in the San José Gulf compared to the Nuevo Gulf. This pattern likely reflects greater trophic availability in the San José Gulf, underscoring its critical role as a migratory stopover site. The study employed encounter-reencounter data from individually marked birds across monitored beaches (2006–2013), providing a robust tool for conservation and management decisions. Such insights are vital for protecting these ecologically sensitive sites, which act as population bottlenecks.
Acute and chronic behavioral effects of kelp gull micropredation on southern right whale mother-calf pairs off Península Valdés, Argentina
Kelp gull micropredation significantly increases respiration rates and alters behavior in southern right whale mother-calf pairs off Península Valdés, Argentina. Even without attacks, whales exhibit ~50% higher respiration rates than undisturbed controls, with calves showing ~25% increases. During attacks, calf respiration spikes an additional 10%, while mothers frequently adopt irregular breathing postures, potentially increasing energy expenditure. Gulls also target previously wounded calves more often. These acute and chronic behavioral changes may have long-term energetic consequences for whale survival and reproduction.
Distribution and environmental determinants of darkling beetles assemblages (Coleoptera: Tenebrionidae) in Península Valdés (Argentinean Patagonia)
Research identifies five distinct environmental units within Península Valdés, each characterized by unique darkling beetle assemblages and species diversity. Temperature, precipitation, and soil texture emerged as the most influential determinants of these distribution patterns. The findings suggest that ecosystem processes may vary significantly among these units, underscoring the need for targeted conservation efforts to protect this biodiversity-rich region in Argentinean Patagonia.
Ocean warming threatens southern right whale population recovery
A significant increase in southern right whale mortality rates following El Niño events has been identified, posing a threat to the recovery of their population at Península Valdés, Argentina. Modeling suggests that more frequent and intense El Niño events could hinder population growth or even lead to decline, potentially disrupting food-web interactions in the Southern Ocean (SO) and weakening its role in global climate change mitigation. The study analyzed photo-identified whales, linking ocean warming and El Niño intensity to adverse impacts on whale survival.
Changing patterns of habitat use by southern right whales (Eubalaena australis) on their nursery ground at Península Valdés, Argentina, and in their long-range movements
Southern right whales (Eubalaena australis) at Península Valdés, Argentina, demonstrate remarkable behavioral and ecological flexibility, as evidenced by changes in their habitat use patterns over four decades. This study, spanning from 1970 to 2020, identified 618 individual whales sighted across multiple years, revealing shifts such as the abandonment of a major concentration region and the establishment of new nursery areas near growing whalewatching industries. Some whales were also resighted on distant feeding grounds and other nursery sites, suggesting long-range movements. Isotope analysis further indicated diverse feeding strategies among individuals. The research highlights the adaptability of these whales to environmental changes, including potential responses to human disturbances.
Conflictos socioterritoriales: la pesca artesanal como bien común en Península Valdés, Argentina
Artisanal fishing in Península Valdés, Argentina, has been recognized as a common good through participatory processes that transcend utilitarian principles and promote the sustainability of fisheries. This study highlights how local fishermen have successfully introduced regulations that balance resource use with ecological preservation. Using ethnographic methods, direct observation, interviews, and document analysis, researchers examined participatory devices that demonstrate the fishermen's role as valid interlocutors in public spaces, despite ongoing tensions. While these processes have fostered tools and capacities for managing fisheries as a common good, challenges persist due to the coexistence of formal and informal activities, territorial privatization, and competition from other economic pursuits.
Demand-driven commercial whalewatching in Península Valdés (Patagonia): conservation implications for right whales
Commercial whalewatching in Península Valdés has seen exponential growth, with over 337,000 tourists participating in boat excursions between 1987 and 1997. This rapid increase, driven by demand for close-up views of southern right whales (Eubalaena australis), particularly pregnant females and calves, raised concerns about potential conservation impacts on the vulnerable species. The study highlights that the absence of a management plan or carrying capacity estimates allows unchecked commercial activity, despite significant economic benefits—generating over $15 million in direct and indirect revenues by 1997. Research involved analyzing tourism data from 11 years to assess growth trends and conservation implications.
Fatty acids and stable isotopes (δ13C, δ15N) in southern right whale Eubalaena australis calves in relation to age and mortality at Península Valdés, Argentina
A study of southern right whale calves at Península Valdés, Argentina, found no significant differences in blubber fatty acid composition or stable isotope ratios (δ13C, δ15N) between dead and living calves, suggesting that maternal diet and foraging ranges were similar among both groups. However, calf length significantly influenced fatty acid profiles, indicating age-related changes due to nursing duration. These findings imply that poor maternal nutrition or differences in feeding grounds are unlikely causes of the high calf mortality observed from 2003 to 2013. The research highlights the importance of further assessing overall health and body condition in southern right whale calves to better understand survival factors.
Relative abundance and activity patterns of terrestrial carnivorous mammals in Península Valdés, Patagonia, Argentina
A study on Península Valdés, Argentina, reveals distinct activity patterns among terrestrial carnivorous mammals. Conepatus chinga and Leopardus geoffroyi exhibit cathemeral activity, while Lycalopex gymnocercus shows a more nocturnal pattern. Puma concolor and Leopardus colocolo were less frequently detected, limiting detailed behavioral analysis. The research used camera traps over 18 months, capturing 256 independent events across diverse plant communities in San Pablo de Valdés Wildlife Reserve. Findings underscore the need for expanded sampling to better understand population dynamics and inform conservation strategies, emphasizing the importance of ecological data in monitoring threatened species.
Dusky dolphin group dynamics and association patterns in Península Valdés, Argentina
Dusky dolphins (Lagenorhynchus obscurus) in Península Valdés, Argentina, exhibit seasonal variations in social structure and group dynamics. The study found that during the cold season, these dolphins form long-term preferred companions, while such bonds loosen or disappear in the warm season when prey availability increases. Researchers analyzed behavioral observations, photo-identification data, and association patterns from 2001 to 2012 using methods like the half-weight association index (HWI) and social differentiation (S). Group fission-fusion dynamics were also linked to feeding behaviors, with fusions primarily occurring for socializing and feeding. The findings suggest that seasonal changes in prey availability drive shifts in both foraging behavior and social structure, providing insights into the adaptability of these marine mammals.
Post-mortem findings in southern right whales Eubalaena australis at Península Valdés, Argentina, 2003-2012
A decade-long investigation into the mortality of southern right whales (Eubalaena australis) at Península Valdés, Argentina, revealed alarming trends with no clear cause for the majority of deaths. Between 2003 and 2012, 605 whale strandings were recorded, including a peak of 116 in 2012, with calves-of-the-year representing 89.9% of cases. Post-mortem examinations on 212 whales identified only 6.6% with known or probable causes, such as ship strike, blunt trauma, pneumonia, myocarditis, and meningitis. Pathogen testing for viruses and parasites yielded negative results in most cases, except for Brucella spp. in a newborn with pneumonia. Ante-mortem gull parasitism was common but rarely linked to systemic disease. The study highlights the need for further research to identify consistent causes behind these significant mortality events.
Increased Wounding of Southern Right Whale (Eubalaena australis) Calves by Kelp Gulls (Larus dominicanus) at Península Valdés, Argentina
A dramatic increase in the wounding of southern right whale (Eubalaena australis) calves by Kelp Gulls (Larus dominicanus) at Península Valdés, Argentina, has been documented over the past four decades. The study found that while only 2% of mother-calf pairs showed gull lesions in the 1970s, this figure rose to 99% by the 2000s. Calves, particularly those older during the calving season, suffered more extensive and numerous lesions compared to their mothers, with some bearing nine or more wounds covering a significant area of their backs. The research analyzed aerial survey photographs of living pairs (1974-2011) and stranding photographs of dead calves (2003-2011), revealing that intensified gull harassment could potentially compromise calf health by leading to dehydration, impaired thermoregulation, and energy loss due to wound healing. However, this trend does not fully explain the large year-to-year variance in calf mortality rates observed since 2000.
Southern right whale (Eubalaena australis) calf mortality at Península Valdés, Argentina: Are harmful algal blooms to blame?
A concerning increase in southern right whale calf mortality at Península Valdés, Argentina—with 90% of deaths occurring in calves under three months old since 2005—may be linked to harmful algal blooms (HABs). Research identifies a statistically significant correlation between the density of the diatom Pseudo-nitzschia spp. and calf deaths, though no such link was found with the dinoflagellate Alexandrium tamarense. Evidence of whale exposure to HAB toxins includes trace levels of paralytic shellfish toxins (PSTs) and domoic acid (DA) in tissue samples, as well as Pseudo-nitzschia frustules in fecal matter. The study analyzed multiple datasets, including biotoxin levels, algal abundances, shellfish harvesting closures, prey availability, and satellite chlorophyll data, to assess the potential role of HABs in these mortalities.
Range Management Affects Native Ungulate Populations in Península Valdés, a World Natural Heritage
In Península Valdés, a UNESCO World Natural Heritage site, guanaco populations thrive more in areas where ecotourism complements livestock production compared to traditional sheep ranching alone. The study found that smaller paddocks with higher stocking rates and greater vegetation productivity (measured by EVI) correlated with fewer guanaco sightings. However, when ecotourism was integrated into ranch management, guanaco encounter rates increased regardless of paddock size, suggesting reduced human disturbance. Land subdivision emerged as a key predictor of guanaco distribution in sheep-only ranches, while the addition of ecotourism appears to mitigate negative impacts on native ungulates. The research highlights potential strategies for balancing livestock production and wildlife conservation in Patagonian rangelands.
Unexplained recurring high mortality of southern right whale Eubalaena australis calves at Península Valdés, Argentina
A concerning surge in unexplained calf mortality among southern right whales (Eubalaena australis) at Península Valdés, Argentina, between 2003 and 2011, threatens the recovery of a critically depleted subpopulation. During this period, hundreds of calves died, with mortality rates increasing faster than the growth of living calves over the preceding three decades. The pattern of deaths varied seasonally, with some calves reaching at least one meter in length before perishing, suggesting they were healthy prior to death. Large calves (>6 m) also died in early calving seasons (2008-2009), hinting at potential population-wide stressors like nutritional deficiencies. Despite extensive tissue sampling and analysis, no consistent lesions, pathogens, or algal biotoxins have been identified as the cause. This study documents these mortality events, contextualizes them historically, and highlights ongoing efforts to pinpoint their causes, emphasizing the urgent need for conservation action to prevent further decline of this endangered species.
Response of southern right whales to simulated swim‐with‐whale tourism at Península Valdés, Argentina
Southern right whales (Eubalaena australis) exposed to simulated swim-with-whale tourism at Península Valdés, Argentina, showed significant behavioral changes, including reduced resting, socializing, and surface active behaviors, while traveling increased during interactions. Mother-calf pairs exhibited the strongest responses, with faster swimming and more frequent reorientation. These findings raise concerns about the long-term impacts of increased tourism activity on whale behavior, particularly given recent die-offs in the region. The study suggests that legalization of swim-with-whale tourism should be deferred until further investigations are conducted to assess potential long-term consequences.
Response of guanacosLama guanicoeto changes in land management in Península Valdés, Argentine Patagonia: conservation implications
Guanacos (Lama guanicoe) in Península Valdés, Argentina, showed a three-fold increase in abundance within three years following the removal of sheep from a private wildlife reserve. This rapid response suggests that guanacos, even at high densities, are less damaging to vegetation than sheep. The study compared guanaco populations and plant cover inside and outside the reserve, revealing higher guanaco numbers and greater grassland coverage in areas where sheep were excluded. While management changes led to significant local increases in guanaco populations, the researchers emphasize that large-scale protection is necessary for the long-term persistence of wild guanaco populations. The findings highlight the potential for sustainable coexistence between livestock production and wildlife conservation in this UNESCO World Heritage Site.
The Ground-Dwelling Arthropod Community of Península Valdés in Patagonia, Argentina
Predation emerges as a key factor shaping the composition and abundance of ground-dwelling arthropods in Península Valdés, Argentina. This study, the first to employ intensive, planned sampling over three summers (2005–2007), revealed that predators dominate the community, with ants (Hymenoptera: Formicidae) leading in abundance, followed by beetles (Coleoptera) and spiders (Araneae). Two new species were identified from this data. The logarithmic distribution of abundances suggests limited controlling factors, while the predominance of predators highlights their critical role in structuring arid Patagonian ecosystems. These insights offer valuable guidance for conservation efforts in UNESCO-listed Península Valdés.
You are here:
World Heritage Explorer > World Heritage Research > World Heritage Sites > Península Valdés