South American Sea Lion Otaria Research Articles

Bottom-up processes drive isotopic variation in the South American sea lion Otaria flavescens across a 2300 km latitudinal gradient

Spatial differences in the isotope values of widely distributed marine apex consumers may reflect geographical differences in the isotopic composition of basal resources (e.g., phytoplankton) fueling food webs (bottom-up effects) or spatial differences in the trophic ecology of the taxon of interest (top-down effects). We examined spatial variation in δ13C and δ15N values from 264 South American sea lions (SASL, Otaria flavescens) of different age classes (adults, subadults and juveniles), their putative prey consisting of pelagic and benthic coastal fishes, and particulate organic matter (POM) measured from locations situated across >2300 km of the Chilean coast (between 18°42′ and 39°17′ S). We used generalized least squares (GLS) models to compare the form of the relationship between δ13C and δ15N and latitude between the three functional groups. Our results show that SASL from northern, central, and southern areas were isotopically distinct, with individuals from the north having lower δ13C and higher δ15N values in comparison to individuals from the south. When the relationship for each functional group was modelled individually using GLS, results indicated that for each degree of increasing latitude δ15N decreased on average by 0.12‰ (POM), 0.15‰ (prey), and 0.14‰ (SASL), while δ13C increased by 0.06‰ (POM) and 0.05‰ in both prey and SASL. We suggest that the latitudinal differences observed in SASL δ13C and δ15N values reflect baseline isotopic variation rather than marked differences in trophic ecology of these widely distributed consumers.

Immunolocalization of Two Neurotrophins, NGF and BDNF, in the Pancreas of the South American Sea Lion Otaria flavescens and Bottlenose Dolphin Tursiops truncatus.

In this study, we have investigated the immunolocalization of NGF (Nerve Growth Factor) and BDNF (Brain-Derived Neurotrophic Factor) in the pancreas of two species of marine mammals: Tursiops truncatus (common bottlenose dolphin), belonging to the order of the Artiodactyla, and Otaria flavescens (South American sea lion), belonging to the order of the Carnivora. Our results demonstrated a significant presence of NGF and BDNF in the pancreas of both species with a wide distribution pattern observed in the exocrine and endocrine components. We identified some differences that can be attributed to the different feeding habits of the two species, which possess a different morphological organization of the digestive system. Altogether, these preliminary observations open new perspectives on the function of neurotrophins and the adaptive mechanisms of marine mammals in the aquatic environment, suggesting potential parallels between the physiology of marine and terrestrial mammals.

Concentrations of lead in pinniped bones confirm Galapagos as a relatively unpolluted environment

Lead (Pb) is a trace element that is naturally present in arid regions but it is also released to the marine environment by anthropogenic industrial emissions. Here, we assessed Pb concentrations in bone samples of four pinniped species: the Galapagos sea lion Zalophus wollebaeki, sampled in Galapagos archipelago, the monk seal Monachus monachus from Mauritania, and the South American fur seal Arctocephalus australis and the South American sea lion Otaria flavescens, from Uruguay, and investigate potential geographic differences. Concentrations of lead in the samples from Galapagos were lower than those detected in samples from Mauritania and Uruguay, indicating that the Galapagos archipelago is a comparatively pristine spot for this toxic element as related to the other two areas. The waters of Mauritania and Uruguay are likely affected by the inputs of lead brought by the desert dust and released by the local industry, respectively. This study supports the use of bone to assess lead concentrations in biota, as well as the use of pinnipeds as bioindicators of marine pollution.

Sea lion and fur seal interactions with fisheries and aquaculture in South American waters: threats and management perspectives

Abstract The main issue affecting the conservation of most pinniped species has been identified as interactions with fisheries and aquaculture. In South American waters in particular, this problem has not been well evaluated. Consequently, there is an urgent need for research and conservation measures to address the problem, particularly for species of conservation concern. In this study, we reviewed published and unpublished research and observations from the last 25 years on operational and biological interactions between pinnipeds and fisheries and salmonid aquaculture activities in South American waters, and the conservation and management implications of these interactions in the near future. Two species of pinnipeds are primarily involved in biological and operational interactions with fisheries and aquaculture in South America: the South American sea lion Otaria flavescens and the South American fur seal Arctocephalus australis. Although phocids are present in South American waters, there is no published research on conflicts between phocids and human activities. Interactions between fisheries and pinnipeds have been reported by many countries. In South American waters, interactions mostly involve male and subadult male South American sea lions. However, despite the high frequency of interactions, the estimated economic losses to fisheries and aquaculture related to sea lion depredation are generally low. Incidental capture and mortality of pinnipeds has been reported, especially in artisanal gillnet fisheries and in industrial purse seine and trawl fisheries. Mortality of sea lions in salmonid aquaculture has been reported, but the magnitude of the problem is unknown. In South America, limited progress has been made to incorporate mitigation measures, such as time‐area closures, acoustic deterrent devices, and modifications to fishing gear, into fisheries and aquaculture. This is likely to be due to our limited understanding of ecosystem complexity, the costs of modifying fishing gear or incorporating acoustic deterrent devices, and the scarcity of fishing controls. We suggest that strategies for effectively reducing conflicts between pinnipeds, fisheries, and aquaculture should involve all stakeholders in participative research to facilitate co‐management.

Off-seasonal copulation of South American sea lion Otaria byronia in the Chilean Central Coast

El lobo marino común Otaria byronia se distribuye ampliamente en Sudamérica desde Perú pasando por Chile hasta Brasil en los océanos Pacífico y Atlántico, respectivamente. Es una especie abundante, muy vágil y sin problemas de conservación. Como todos los pinnípedos, exhibe una reproducción notablemente estacional y sincronizada con ligeras diferencias entre poblaciones, siendo una cópula atemporal el objetivo de esta nota. Durante septiembre de 2020 se realizó un censo de O. byronia en una lobera reproductiva de la costa de Chile central, cuyos individuos sobre una roca fueron observados con binoculares. Ocho individuos de Otaria byronia fueron registrados, de éstos, una pareja se cortejaba mutuamente moviendo sus cabezas, cuerpos y se desplazaban al unísono sobre la roca. Posteriormente el macho (un sub-adulto) montó a la hembra y copularon aproximadamente por 20 minutos tras lo cual, ella sin prisa salto al mar. Durante el cortejo, cópula e interacción, solo el macho emitió sonidos y no se observaron conductas agresivas mutuas, ni que la hembra se opusiera a ser copulada. Tampoco se observó que los otros individuos interactuaban con ellos. La reproducción de O. byronia ocurre durante el verano austral siendo esta cópula inusual para la temporada, sin precedentes en las poblaciones chilenas y en el subcontinente. Diversos aspectos como factores climáticos, fisiológicos o presión antropogénica se pueden sugerir como causas o detonantes de este evento. Lo anterior destaca la necesidad de ampliar los estudios en mamíferos marinos en la costa chilena, explorando el vínculo e impacto de los factores extrínsecos sobre las poblaciones.

Lobos marinos de un pelo sudamericanos Otaria flavescens ¿buenos indicadores de cambios espaciales y temporales relativos en la distribución y abundancia de los recursos marinos?

ABSTRACT. Oceanographic fluctuations and changes in ocean productivity directly affect the abundance and distribution of prey species, which in turn, affect the population status of their predators. In order to have a better understanding of this predator-prey relationship, the aim of the present study was to analyze the diet of the South American Sea Lion Otaria flavescens (Shaw, 1800) in two rookeries of the San Matias Gulf, in northern Patagonia (Argentina). A total of 52 scat samples of O. flavescens were collected in the Promontorio Belén colony and 35 in Caleta de los Loros during the late spring of 2011. The analysis of the samples indicated that at both localities fish occurred in 100% of scats with prey remains, followed by cephalopods (32.3%) and crustaceans (21.4%). The fish Raneya brasiliensis (Kaup, 1856) constituted the main prey taxon, both in terms of occurrence and numerical abundance. The octopod Octopus tehuelchus (d’ Orbigny, 1834) and squids of the genus Doryteuthis constituted the dominant cephalopod prey. It is concluded that sea lions focused their foraging activity on those species of demersal and benthic habits, associated with coastal and shelf waters. Furthermore, this study reports for the first time the feeding habits of the South American Sea Lion colony of Promontorio Belén, second in population size of Río Negro province.

Inferring the impact of past climate changes and hunting on the South American sea lion

AbstractAimMany pinniped species have experienced drastic demographic changes due to their interaction with humans. Most studies, however, have failed to detect recent bottlenecks in otariids from genetic data. The South American Sea Lion Otaria flavescens have a long history of population changes associated with interglacial expansion and hunting to almost extinction. This study aimed at investigating these different demographic fluctuations integrating population genetics and phylogeographic approaches.LocationPacific coast of South America.MethodsEighty‐five samples from the Chilean coast were collected. Eight microsatellite loci were genotyped, and D‐Loop mitochondrial DNA (mtDNA) sequenced. Genetic diversity was assessed, and tests of recent genetic bottlenecks were performed. Past demographic changes were inferred based on neutrality tests, adjustment of a sudden expansion model and Bayesian skyline plots. The magnitude and timing of the different population size changes were further investigated through approximate Bayesian computation (ABC) of coalescent inferences.ResultsThe mtDNA shows relatively high diversity (h = 0.98 and π = 0.01) compared to most otariids, corroborates the divergence between Pacific and Atlantic populations, around 80,000 years ago (ya), and revealed a secondary contact zone in the Magellan strait. Microsatellite data support a second genetic discontinuity at 40°S, associated with post‐glacial colonization of Patagonia. ABC analyses confirmed that glaciation affected the effective population size (Ne) all along the Pacific Coast, between ~50,000 and 15,000 ya. A strong reduction of Ne was also inferred for the hunting period (73–66 ya from sampling).Main conclusionsO. flavescens shows clear signatures of susceptibility to climatic and anthropogenic disturbances and a spatial genetic structure that should be taken into account in the context of management and conservation policies. Yet, despite a recent history of demographic bottlenecks, the genetic diversity remains high, likely a consequence of the demographic dynamics in otariids, characterized by large and connected metapopulations.

Molecular and morphological identification of Adenocephalus pacificus (Cestoda) isolated from South American sea lion Otaria byronia stranded on the northern Peruvian coasts.

The most frequent etiologic agent of diphyllobothriosis in South America and the only one confirmed by molecular data in human cases in Peru is Adenocephalus pacificus (syn. Diphyllobothrium pacificum). This cestode is transmitted by ingestion of the plerocercoids found in marine fish, causing a parasitic zoonosis. The objective of the present study was to identify two cestodes isolated from two specimens of the South American sea lion (Otaria byronia) stranded on the beaches of Huacho and Barranca cities, located on the northern Peruvian coasts, in the department of Lima. Tapeworms were confirmed by morphological characteristics due to the presence of transverse papilla-like tegumental protuberances in proglottids and small sized eggs, as well as by sequencing of the partial cytochrome c oxidase subunit 1 (mtDNA-COI) gene that are congruent with additional available A. pacificus sequences. Even though sea lions in Peru are distributed along the coast and in areas of difficult access, generally located in protected natural areas, the fortuitous finding represented an opportunity to confirm the presence of A. pacificus in South American sea lions. This report of tapeworm A. pacificus could allow future monitoring of the occurrence and geographical distribution of this causative agent in epidemiological studies, since it is one of the main species of zoonotic importance in Peru.

The northernmost haulout site of South American sea lions and fur seals in the western South Atlantic

We present estimates of the seasonal and spatial occupation by pinnipeds of the Wildlife Refuge of Ilha dos Lobos (WRIL), based on aerial photographic censuses. Twenty aerial photographic censuses were analysed between July 2010 and November 2018. To assess monthly differences in the numbers of pinnipeds in the WRIL we used a Generalized Linear Mixed Model. Spatial analysis was carried out using Kernel density analysis of the pinnipeds on a grid plotted along the WRIL. Subadult male South American sea lions (Otaria flavescens) were the most abundant pinniped in the WRIL. Potential females of this species were also recorded during half of the census. The maximum number of pinnipeds observed in the WRIL was 304 in September 2018, including an unexpected individual southern elephant seal (Mirounga leonina), and a high number of South American fur seal yearlings (Arctocephalus australis). However, there was no statistically significant difference in counts between months. In all months analysed, pinnipeds were most often found concentrated in the northern portion of the island, with the highest abundances reported in September. This study confirms the importance of the WRIL as a haulout site for pinnipeds in Brazil, recommends that land research and recreational activities occur in months when no pinnipeds are present, and encourages a regulated marine mammal-based tourism during winter and spring months.

Vulnerability of a top marine predator to coastal storms: a relationship between hydrodynamic drivers and stranding rates of newborn pinnipeds

Coastal storms have increased in recent decades, affecting many species, including the South American sea lion (Otaria byronia). Reports of stranded sea lion pups are becoming common in Chile, presumably due to the increase in the frequency and intensity of coastal storms. To validate this assumption, a 10-year database was built by coupling wave generation and coastal propagation models to correlate pure wave parameters (significant wave height Hs, peak period Tp, normalized wave power Hs2 Tp) and wave parameters including the tidal level (maximum surface elevation η, modified wave power η2 Tp) with records of stranded pups in Cobquecura, the largest breeding colony in central Chile. The correlation between the number of pups stranded per day and wave parameters in the first half of January and the last half of February is poor, while they are stronger for the second half of January and the first half of February. The higher number of stranded pups coincide with coastal storms with normalized wave power values exceeding a threshold of 100 m2/s. Conversely, below this threshold there is wide dispersion between the number of strandings and wave parameters. Identifying wave parameter thresholds could be used to predict when newborn pups will be most affected by coastal storms, and thus help institutions to develop remediation techniques for animals at risk.

Spontaneous Yawning and its Potential Functions in South American Sea Lions (Otaria flavescens)

Spontaneous yawning is a widespread behaviour in vertebrates. However, data on marine mammals are scarce. In this study, we tested some hypotheses on the functions of yawning in a captive group of South American sea lions (Otaria flavescens). According to the Dimorphism Hypothesis, species showing low levels of sexual dimorphism in canine size do not show sex differences in yawning distribution; this was supported by our findings, since yawning did not differ between the sexes. Yawning was more frequently performed during resting/sleeping contexts, thus supporting the Drowsiness Hypothesis. Yawning and self-scratching are considered reliable indicators of short-term anxiety in sea lions, since they immediately increased after conflicts both in aggressors and victims (Social Distress Hypothesis supported). In the long-term, yawning was not correlated with individuals’ dominance status, thus showing that anxiety is similarly experienced by dominants and subordinates. The last two findings can be explained by the social competition of this species, that involves individuals independently from their sex, age or ranking status. Therefore, the exposure to frequent stressful events can induce similar levels of anxiety in all the subjects (Resource Inequity Hypothesis supported). In conclusion, spontaneous yawning in sea lions seems to share similar functions with other social mammals, suggesting that this behaviour is a possible plesiomorphic trait.

Tuberculosis caused by Mycobacterium pinnipedii in a wild South American sea lion Otaria flavescens stranded in southern Brazil.

Tuberculosis (TB) in pinnipeds is typically caused by Mycobacterium pinnipedii, which has also been associated with infections in other species, such as cattle and humans. As a result, this pathogen has zoonotic potential and is a public health concern. In 2016, a female South American sea lion Otaria flavescens in southern Brazil presented with emaciation and severe dyspnea and died within 3 h of capture. Gross pathology identified pulmonary granulomas, and Ziehl-Neelsen stain identified acid-fast bacilli. M. tuberculosis complex bacteria were confirmed by a BD BACTEC™ MGIT™ 320 detection system using fibrinous exudate, lung granulomas and thoracic fluid. Molecular characterization by spoligotyping showed a hybridization pattern characteristic of M. pinnipedii (SIT593/PINI1). Currently, there is a paucity of data concerning the transmission and epidemiology of M. pinnipedii in pinniped populations in South America. The case report shows that the disease appeared in a free-ranging beached sea lion on the coast, and further surveillance is needed to determine the origin of this TB because of its potential impact on public health.

Antarctophthirus microchir infestation in synanthropic South American sea lion (Otaria flavescens) males diagnosed by a novel non-invasive method

Antarctophthirus microchir is a sucking louse species belonging to the family Echinophthiriidae and has been reported to parasitize all species of the subfamily Otariinae, the sea lions. Former studies on this ectoparasite mainly required fixation, immobilization, or death of host species and especially examinations of adult male sea lions are still very rare. Between March and May 2018, adult individuals of a unique “urban” bachelor group of South American sea lions (Otaria flavescens) living directly in the city of Valdivia, Chile, were studied regarding their ectoparasite infestation status. For first time, a non-invasive method in the form of a lice comb screwed on a telescopic rod and grounded with adhesive tape was used for sample taking process. Overall, during combing different stages of A. microchir were detected in 4/5 O. flavescens individuals, especially at the junction between the back and hind flippers. Our findings represent the first report of A. microchir infesting individuals of this synanthropic colony and fulfilling complete life cycle in a sea lion group despite inhabiting freshwater and in absence of females/pups. Our “telescopic lice comb apparatus” offers a new strategy to collect different stages of ectoparasites and a range of epidermal material, such as fur coat hair and superficial skin tissue for a broad spectrum of research fields in wildlife sciences in an unmolested and stress reduced manner.

Small-scale variation in the diet of the South American Sea lion (Otaria flavescens) in northern Patagonia (Argentina)

An understanding of the mechanisms that shape animal-population dynamics is a fundamental consideration in conservation biology and ecology. Populations of the species of South-American sea lions (SASLs) Otaria flavescens reveal different growth rates, which variations could be linked to changes in the accessibility of nutritional resources in any given location. The available information on differences in the SASL diet on a local scale, however, is relatively scarce. We therefore searched for evidence of geographical variations in the diet of the SASLs in Northern Patagonia—namely, in the Golfo San Matías (GSM) and the Golfo Nuevo (GN), both of which bays are quite different regarding their physiography, oceanography, and anthropic pressures. From 2005–2013, stomach samples ( nGSM=39; nGN=31) were collected from animals found dead on the coast or accidentally caught in fishing nets. The dietary composition differed between the two gulfs with respect to the most common species, the zoological groups, and the sizes of the primary prey. In the GSM, the SASLs fed on demersal–pelagic fish, while in the GN the diet exhibited a high contribution of benthic species. Differences in the items and sizes of prey consumed at each area are discussed in terms of differential prey availability along with the opportunistic feeding behavior of this predator. These differences, in addition to the species’s main prey as targets for major fisheries, must be taken into account in order to understand the different population dynamics of this apex predator and thus ensure its conservation.

Marine mammal bycatch by the industrial bottom trawl fishery at the Rio de la Plata Estuary and the adjacent Atlantic Ocean

Fisheries interactions with non-target marine vertebrates are a worldwide problem. The impact of coastal bottom trawl fisheries on marine mammals has never been evaluated before in the Rio de la Plata Estuary and the adjacent Atlantic Ocean. Our aim was estimating the bycatch per unit effort (BcPUE) and incidental mortality rates of marine mammals caused by the industrial coastal bottom trawl fisheries fleet. We evaluated the mortality of three species ( i.e ., franciscana dolphin Pontoporia blainvillei , South American sea lion Otaria flavescens , and the South American fur seal Arctocephalus australis ); these species are facing conservation problems either at the regional or local scale. We conducted an onboard data collection program of marine mammals' bycatch involving crew members of 10 vessels (30%) of the Uruguayan coastal bottom trawl fleet between January 2009 and April 2012. A total of 102 marine mammal individuals were bycaught during 490 fishing trips involving 2,398 fishing days. Mortalities estimated for franciscana dolphin were the highest among the species affected, with values adding up to ~100 individuals for year (with scenarios of population decline in the area), followed by South American sea lion with ~77 individuals by year (0.8% of local population) and the South American fur seal with an annual mortality estimate of ~25 individuals (~0.02% of local population). BcPUE showed significant temporal variation, with franciscana dolphin BcPUE varying seasonally and those of otariids according to their breeding season. Our estimates of marine mammal bycatch by bottom trawl fisheries should constitute an important input for the sustainable management of fisheries and the conservation of marine biodiversity in the southwestern Atlantic Ocean.

Transmission of Corynosoma australe (Acanthocephala: Polymorphidae) from fishes to South American sea lions Otaria flavescens in Patagonia, Argentina.

Acanthocephalans display a two-host life cycle that involves arthropods as intermediate hosts and vertebrates as definitive hosts. Some species also use paratenic hosts to bridge the trophic gap between both obligatory hosts. However, the relative role of these paratenic hosts in the transmission to definitive hosts has seldom been assessed quantitatively. We report on infection patterns of cystacanths of Corynosoma australe Johnston, 1937 in 20 common teleost species and the Argentine shortfin squid Illex argentinus (Castellanos) from the Patagonian shelf of Argentina. We also explore the role of different fish species in the transmission of C. australe to the most important definitive host in the area, i.e. the South American sea lion Otaria flavescens Shaw. Cystacanths of C. australe were found in all host species except Heliconus lahillei Norman, Merluccius hubbsi Marini and I. argentinus. In eight fish species, the prevalence of C. australe was > 50% and mean intensity > 4, i.e. Acanthistius patachonicus (Jenyns), Nemadactylus bergi (Norman), Paralichthys isosceles Jordan, Percophis brasiliensis Quoy & Gaimard, Prionotus nudigula Ginsburg, Scomber colias Gmelin, Raneya brasiliensis (Kaup) and Xystreurys rasile (Jordan). Two surveys on the trophic ecology of South American sea lions in the study area consistently found a generalist diet dominated by M. hubbsi, and data on the frequency of occurrence and number of other fish and cephalopod species in stomach contents strongly suggest that only R. brasiliensis may play a prominent role in the transmission of C. australe. This result raises interesting questions on the costs of paratenicity.

From mammals back to birds: Host-switch of the acanthocephalan Corynosoma australe from pinnipeds to the Magellanic penguin Spheniscus magellanicus.

Trophically-transmitted parasites are regularly exposed to potential new hosts through food web interactions. Successful colonization, or switching, to novel hosts, occur readily when ‘donor’ and ‘target’ hosts are phylogenetically related, whereas switching between distantly related hosts is rare and may result from stochastic factors (i.e. rare favourable mutations). This study investigates a host-switching event between a marine acanthocephalan specific to pinnipeds that is apparently able to reproduce in Magellanic penguins Spheniscus magellanicus from Brazil. Detailed analysis of morphological and morphometrical data from acanthocephalans from penguins indicates that they belong to Corynosoma australe Johnston, 1937. Partial fragments of the 28S rRNA and mitochondrial cox1 genes were amplified from isolates from penguins and two pinniped species (i.e. South American sea lion Otaria flavescens and South American fur seal Arctocephalus australis) to confirm this identification. Infection parameters clearly differ between penguins and the two pinniped species, which were significantly lower in S. magellanicus. The sex ratio of C. australe also differed between penguins and pinnipeds; in S. magellanicus was strongly biased against males, while in pinnipeds it was close to 1:1. Females of C. australe from O. flavescens were smaller than those from S. magellanicus and A. australis. However, fecundity (i.e. the proportion of fully developed eggs) was lower and more variable in females collected from S. magellanicus. At first glance, the occurrence of reproductive individuals of C. australe in Magellanic penguins could be interpreted as an adaptive colonization of a novel avian host through favourable mutations. However, it could also be considered, perhaps more likely, as an example of ecological fitting through the use of a plesimorphic (host) resource, since the ancestors of Corynosoma infected aquatic birds.

A Simulation-Based Study on Bayesian Estimators for the Skew Brownian Motion

In analyzing a temporal data set from a continuous variable, diffusion processes can be suitable under certain conditions, depending on the distribution of increments. We are interested in processes where a semi-permeable barrier splits the state space, producing a skewed diffusion that can have different rates on each side. In this work, the asymptotic behavior of some Bayesian inferences for this class of processes is discussed and validated through simulations. As an application, we model the location of South American sea lions (Otaria flavescens) on the coast of Calbuco, southern Chile, which can be used to understand how the foraging behavior of apex predators varies temporally and spatially.

Anthropozoonotic Endoparasites in Free-Ranging "Urban" South American Sea Lions (Otaria flavescens).

The present study represents the first report on the gastrointestinal endoparasite fauna of a free-ranging “urban” colony of South American sea lions (Otaria flavescens) living within the city of Valdivia, Chile. A total of 40 individual faecal samples of South American sea lions were collected during the year 2012 within their natural habitat along the river Calle-Calle and in the local fish market of Valdivia. Coprological analyses applying sodium acetate acetic formalin methanol (SAF) technique, carbol fuchsin-stained faecal smears and Giardia/Cryptosporidium coproantigen ELISAs, revealed infections with 8 different parasites belonging to protozoan and metazoan taxa with some of them bearing anthropozoonotic potential. Thus, five of these parasites were zoonotic (Diphyllobothriidae gen. sp., Anisakidae gen. sp., Giardia, Cryptosporidium, and Balantidium). Overall, these parasitological findings included four new parasite records for Otaria flavescens, that is, Giardia, Cryptosporidium, Balantidium, and Otostrongylus. The current data serve as a baseline for future monitoring studies on anthropozoonotic parasites circulating in these marine mammals and their potential impact on public health.

Observations of the effect of a New Year’s fireworks display on the behavior of the South American sea lion (Otaria flavescens) in a colony of central-south Chile

The use of fireworks has increased worldwide in recent years. Despite this, their effects on sea lions and similar species are almost undocumented. In this study, we documented some effects of the 2015 New Year’s fireworks on the behavior of South American sea lions (Otaria flavescens), a marine mammal species that utilizes coastal rookeries for breeding, resting, and care and nursing of pups. An immediate cessation of vocalizations followed the start of the fireworks and a significant decrease in the number of sea lions in the colony was registered. This provided evidence that fireworks disrupted the ongoing behavior of the South American sea lion. Further studies will be necessary to determine whether this disruption has negative consequences for these animals or whether they have evolved behavioral mechanisms for dealing with these kinds of short-term disruptive events.