Doris Oliva

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• Licenciado en Ciencias
• Profesor Titular at University of Valparaíso

The coastal wetlands of northern Chilean Patagonia are relevant sites for the conservation of migratory waterbirds. The aim of this paper is to compare different marine coastal wetlands to identify which factors influence the structure of bird assemblages. Sediment samples were collected, and the birds were surveyed in four wetlands: Chullec, Curac...

1. 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 c...

Harmful Algal Blooms (HABs) have been classified depending on the causative organism and its impacts: non-toxic HAB (microalgae capable of affecting tourism and causing oxygen deficiency, which generates mortality of marine organisms), toxic HAB (microalgae capable of transferring toxins to the food chain), and ichthyotoxic HAB (microalgae capable...

Tawera elliptica (, commonly known as “Almeja Juliana”, is a venerid clam that inhabits sandy bottoms and is distributed from Valparaíso on the Pacific coast up to the Mar del Plata area along the Atlantic coast. Harvests of this clam have declined substantially over the last decade. Therefore, an analysis of common parasites and pathological condi...

Artificial cultivation increases clams' availability and is an alternative to the extraction from natural banks. The culture of clams requires species-specific research in the different growth stages, and studies on the effects and interactions of culture parameters are essential to obtain and control the proper development of larvae. This paper ai...

Simple Summary The surf clam Mesodesma donacium, known in the Southeastern Pacific as “macha”, has experienced decreased availability for local consumption due to high levels of extraction for many years in Chile and the effect of El Niño Southern Oscillation (ENSO) in Perú. To compensate the population decline, the advancement of the development o...

Objectives Here, we present the first record of stable colonies of the South American fur seal ( Arctocephalus australis ), in an area where their presence has never been documented (hereafter distribution gap), as well as an update of the current distribution range of the species in central Chile. Results A national synoptic aerial census of pinn...

Although pesticides are the most widely used method for the control of agricultural pests, natural insect enemies can successfully suppress pest populations. However, side effects of pesticides can have strongly deleterious impacts on these biocontrol agents. In this context, lethal (mortality over time) and sublethal (oxidative stress) effects of...

The effects of human-caused mortality, such as fisheries bycatch, of endangered, threatened and protected (ETP) species of marine mammals can be evaluated using population model-based stock assessments. The information available to conduct such assessments is often very limited. Available data might include fragmented time-series of abundance estim...

Tawera elliptica is a small size (baby) clam with an export fishery in southern Chile. The species is dioecious with external fertilization and without sexual dimorphism. The aim of this work was to optimize broodstock conditioning, induce spawning and describe embryonic development until the early larval stage in a hatchery. Broodstock were condit...

Semillas (spats) de Mulinia edulis, producidas en hatchery, se engordaron durante 40 días, en un sistema de cultivo suspendido (long-line) en el mar en Bahía Yal (Chiloé, Chile), con el objetivo de probar la factibilidad de pre-engorda. Se utilizaron dos tamaños de siembra 2,9 y 6,2 mm y dos densidades [1 (D1) y 2 (D2) semillas cm-2] en tratamiento...

The aim of this study was to use scat analysis to analyse the dietary composition of the South American sea lion (SASL, Otaria byronia) over a short temporal scale and in different but closely located colonies in the Humboldt Current System of northern Chile. Scat samples were collected at Arica (18°34′S), Iquique (20°48′S) and Mejillones (23°04′S)...

Repeated reports of microplastic pollution in the marine pinniped diet have emerged in the last years. However, only few studies address the drivers of microplastics presence and the potential implications for monitoring microplastic pollution in the ocean. This study monitored their in the scats (N = 205) of four pinniped species/subspecies at fiv...

The South American fur seal (SAFS), Arctocephalus australis, has an estimated abundance of 219,000 individuals. The distribution range of this top marine predator along the Pacific coast of South America is discontinuous, with a gap between 29°02’S-43°36’S, whereas the Atlantic coast presents a continuous distribution. Little is known about the pop...

The southern elephant seal (SES), Mirounga leonina, has an estimated abundance of 900,000 individuals and a nearly circumpolar distribution in the Southern Hemisphere. In Chile, the species inhabits three colonies in the Magallanes Region (54°24′S) and the northernmost sightings have been attributed to vagrant individuals. The aim of this study is...

The South Pacific Hake (Merluccius gayi) is the main artisan gillnet fishery in central Chile and the South American sea lion (SASL, Otaria byronia) has a strong operational interaction with this fishery. This was analyzed in paper [2] and several issues, like ignorance regions and spatial variation of such conflicts have not been studied in detail...

Objetivo: Evaluar la tendencia poblacional del lobo marino sudamericano, Otaria byronia, durante los últimos 20 años, dando cuenta de los cambios en la distribución de loberas, abundancia y número de loberas reproductivas en la costa de Chile.

Studies under laboratory and field conditions have shown that juvenile Mulinia edulis clams measuring 5–15 mm are able to tolerate transfer times of over 24 hr and burrow successfully. Burrowing generally followed an asymptotic curve over time, with a rapid initial phase for smaller juveniles, which slowed over time. In laboratory conditions, at lo...

Chemical composition, morphometry and meat yield of Mulinia edulis, were analyzed for two size groups and two locations. The clams were taken from natural beds, one located in the north (Peñuelas; 29°55´S) and the second in the south (Putemún; 42°25´S) of Chile. The first size group corresponds to legal catch size (>5.5 cm) and the second to ‘baby...

Tawera elliptica, conocida como almeja juliana, es una almeja de pequeño calibre cuyos bancos han sido fuertemente explotados en el mar interior de Chiloé. Es una especie dioica sin dimorfismo sexual y con fecundación externa. Reproductores de Tawera elliptica fueron acondicionados durante 49 días y alimentados con una dieta de 60% de Isochrysis ga...

The South American sea lion (SASL, Otaria byronia) is one of the species of pinnipeds that display the strongest level of conflict with fishing activities throughout its distribution range. However, little is known about potential temporal and/or spatial variations in the magnitude and effects of SASL and fishing interactions over an entire year an...

Biotic and abiotic factors determine presence and habitat use pattern of individuals within a population. In this study, presence, behavior, and resighting patterns of transient bottlenose dolphins (Tursiops truncatus) were evaluated in relation to upwelling and downwelling events in a marine reserve in North-Central Chile, between 2005 and 2009. T...

The increase in the exploitation of clams has produced a reduction in the artisanal CPUE and landing. Therefore, the importance of developing a technology for culture and commercial production of burrowing bivalves is evident. The aim of this work is to make an analysis of bivalves with biologic and market potential in Chile, to establish the state...

Mulinia edulis (King, 1832), comúnmente conocida como almeja “Taquilla”, se distribuye desde el Callao (Perú), hasta el estrecho de Magallanes y Tierra del Fuego en el sur de Chile (Oliva et al. 2005, Jaramillo et al. 2008). Habita parcialmente enterrada en fondos fango-arenosos cerca del nivel inferior de mareas en costas protegidas y en zonas que...

La almeja juliana, actualmente denominada como Tawera elliptica (Lamarck, 1818), es una almeja dioica, sin dimorfismo sexual y con fecundación externa, además presenta un ciclo reproductivo continuo asincrónico, sin un periodo de reposo gonadal evidente. Estudios posteriores confirman actividad gametogénica continua durante todo el año, donde la ev...

Apex marine predators alter their foraging behavior in response to spatial and/or seasonal changes in natural prey distribution and abundance. However, few studies have identified the impacts of aquaculture that represents a spatially and temporally predictable and abundant resource on their foraging behavior. Using satellite telemetry and stable i...

Abstract.- In order to evaluate the effect of stocking density on growth and survival, veliger larvae of Mulinia edulis were reared at densities of 10 and 20 larvae ml-1 fed with a mix of 25,000 cells ml-1day-1 of Isochrysis aff. galbana (T-ISO) and Nannochloropsis oculata in 5 L buckets. In ration experiments, larvae were fed with of 25,000 and 50...

Efecto de dietas en base a microalgas tradicionales, nativas y dietas artificiales sobre el crecimiento y supervivencia en larvas velígeras de la almeja taquilla, Mulinia edulis Effect of traditional microalgae-based food, native and artificial diets on growth and survival of the taquilla clam veliger larvae, Mulinia edulis Abstract.-Three sequenti...

Three sequential experiments were performed to assess the effect of 9 diets of traditionally used microalgae, native microalgae and artificial diets on the survival and growth rate of veliger larvae of the clam Mulinia edulis. Larvae were obtained from broodstock collected from natural banks in the Isla Grande de Chiloé, Region de Los Lagos, Chile....

Diet studies of the South American sea lion (SASL) in Chile suggest that this species is an opportunistic and generalist predator whose diet varies depending on the distribution of prey species and spatial and temporal variations in the abundance of these dams. However, these studies have been sporadic, geographically limited and based on stomach c...

We determined the effect of stocking density and type of diet on the growth and survival of post-larvae of the taquilla clam Mulinia edulis, as a contribution to the development of technology for the commercial cultivation of this species. Larval cultures of 14 days gave rise to postlarvae which were cultivated in closed systems in sand for 30 days...

Seaweeds are well known to concentrate metals from seawater and have been employed as monitors of metal pollution in coastal waters and estuaries. However, research showing that various intrinsic and extrinsic factors can influence metal accumulation, raises doubts about the basis for using seaweeds in biomonitoring programmes. The thallus of brown...

We tested the validity of Bergmann's rule and Rosenzweig's hypothesis through an analysis of the geographical variation of the skull size of Otaria flavescens along the entire distribution range of the species (except Brazil). We quantified the sizes of 606 adult South American sea lion skulls measured in seven localities of Peru, Chile, Uruguay, A...

Seeds of the clam Mulinia edulis produced in a hatchery were grown in bottom cages in the subtidal zone of Tongoy Bay (northern Chile) and in the intertidal zone of Chullec (Chiloe Island, southern Chile), to compare the growth and survival of small and large seeds of the same production in different environments and latitudes. Seeds were shipped t...

The South american sea lion (Otaria flavescens), is one of the species of marine mammals in South America that interacts with all human activities, mainly fisheries, aquaculture and tourism throughout the whole distribution area. On occasions is also affected by industrial activities and oil extraction and maritime transport. Its distribution in So...

Seeds of the clam Mulinia edulis produced in a hatchery were grown in bottom cages in the subtidal zone of Tongoy Bay (northern Chile) and in the intertidal zone of Chullec (Chiloé Island, southern Chile), to compare the growth and survival of small and large seeds of the same production in different environments and latitudes. Seeds were shipped t...

The onshore distribution and abundance of the South American sea lion Otaria flavescens along the central Chilean coast was estimated during the period January-February 2007. Additionally, changes in population abundance during the period 1970-2007 were examined. Population surveys were based on photographs taken from boats or aircraft. A total of...

The onshore distribution and abundance of the South American sea lion Otaria flavescens along the central Chilean coast was estimated during the period January-February 2007. Additionally, changes in population abundance during the period 1970-2007 were examined. Population surveys were based on photographs taken from boats or aircraft. A total of...

The onshore distribution and abundance of the South American sea lion Otaria flavescens along the central Chilean coast was estimated during the period January-February 2007. Additionally, changes in population abundance during the period 1970-2007 were examined. Population surveys were based on photographs taken from boats or aircraft. A total of...

Environmental policy and legislation pursuing the protection of marine ecosystems have commonly considered pollutant content in abiotic matrices. Nevertheless, this approach does not describe the eventual effects on living organisms. The aim of this study was to couple two monitoring tools for environmental diagnostics: the chemical tool, metal con...

El informe da cuenta de los efectos ecologicos y sociales del derrame de petroleo acontecidos en la bahía de Quintero un año después del evento, ademas de información histórica de contaminantes en sedimentos y recursos hidrobiológicos.

The South American sea lion Otaria flavescens is abundant off southern Chile. Because Chilean salmon farming has experienced an explosive growth in the past two decades, interactions between O. flavescens and this industry have increased. Fieldwork, including in situ behavioural observations, was carried out at three salmon farms off southern Chile...

From January 2007 to March 2008, we examined variation in the abundance of the South American sea lion Otaria flavescens in Chañaral Island breeding colony by sex, age-class, and reproductive seasonality. The number of sea lions on land was highest during the breeding season. This variation was mainly influenced by the number of adult females, beca...

Abstract Juvenile northern Chilean scallops of 937±55 m shell height were exposed to five different concentrations of chloramphenicol (CHL) (5, 10, 25, 50 and 100 g mL−1), plus a control without antibiotics. To determine the effect of CHL on the accompanying microflora, the number of colony-forming units (CFU) that grew on TGE culture medium was...

From January 2007 to March 2008, we examined variation in the abundance of the South American sea lion Otaria flavescens in Chañaral Island breeding colony by sex, age-class, and reproductive seasonality. The number of sea lions on land was highest during the breeding season. This variation was mainly influenced by the number of adult females, beca...

Existe consenso en que la diversidad biológica de nuestro planeta se encuentra globalmente en crisis, debido a su empobrecimiento y al hecho de que las futuras generaciones probablemente no tendrán la misma opción de gozar de los múltiples beneficios, servicios y recursos con que actualmente contamos. Por esta razón, un modelo de desarrollo sustent...

Alejandra Urra, Doris Oliva, and Maritza Sepúlveda (2007) Use of a morphometric analysis to differentiate Adelomelon ancilla and Odontocymbiola magellanica (Caenogastropoda: Volutidae) of southern Chile. Zoological Studies 46(3): 253-261. The volutid snails Adelomelon ancilla and Odontocymbiola magellanica are of economic importance to the fishery...

A longstanding competition for fishery resources has existed in Chile between the South American sea lion (Otaria flavescens) and artisanal (small-scale) fisheries. This competition is viewed as a conflict by the fishermen because sea lions prey on fish caught in their fishing gear, often causing its damage. The objective of the study was to descri...

By means of surveys in 48 salmon farms in Chile, and the analysis of fish mortality in 23, the results showed that attacks by the South American sea lion, Otaria flavescens, were periodical at a daily and seasonal scale, and because of their natural nocturnal feeding behaviour, were more frequent at night and in fall-winter seasons. The attacks var...

The first results obtained from archaeological excavation at 10 PM 014 site "Conchal Piedra Azul" are presented. This is a base camp of canoeists prehistoric populations that consist of a shell midden deposit, formed by superimposed occupations. The cultural material shows a hunting-gathering & fishing way of life (ca. 5.000 cal. BP.- to late prehi...

In otariids the presence of circarhythms activity has been studied on the basis of population density changes in sea lion colonies. In this work, the circadian rhythm (24 h) and the circannual rhythm (a year) of the South American sea lion Otaria flavescens from Cochoa and Punta Curaumilla colonies in Central Chile were studied. The circadian rhyth...

En otáridos se han estudiado la presencia de circaritmos de actividad sobre la base de cambios en las densidades poblacionales en las loberas. En este trabajo, se estudiaron los ritmos circadiano (24 h) y circanual (1 año) del lobo marino común Otaria flavescens en las loberas de Cochoa y Punta Curaumilla en Chile Central. El ritmo circadiano fue e...

The large industrial fishery development that turn Chile into the third fishing nation in the world is described, and recent regulatory innovations introduced by new Fishery and Aquaculture legislation are reviewed. In addition to classical Fishery management tools, different types of limited entry systems are now defined in the law and applicable...

INTRODUCCION El presente trabajo tiene por objeto comunicar los resultados de la investigación arqueológica en los asentamientos arcaicos de "Cerro Las Conchas", especialmente aquellos referidos a los recursos comprometidos en la subsistencia. El sitio 07 Ch 014 "Cerro Las Conchas" se encuentra ubicado en la localidad de Reloca, Comuna de Chanco, P...

The activity rhythms of F. crassa which inhabits in the intertidal and F. latimarginata in the subtidal zone are studied. The results show an absence of circatidal activity rhythms in both species, F. crassa and F. latimarginata. Nevertheless in laboratory conditions a circadian activity rhythm is observed in F. crassa and is absent in F. latimargi...

Coseismic uplift from the Chilean earthquake of 3 March 1985 caused changes in the biomass and vertical zonation of rocky intertidal organisms at four sites along 150 km of the central Chilean coast. The 11–60 cm uplift caused widespread mortality mainly of the dominant intertidal kelp Lessonia nigrescens, reducing its biomass in the upper part of...

The specific epithets most commonly used for the southern sea lion have been jubata, leonina, flavescens and byronia. The latter two are still currently in use. The re-examination of the names that have been applied to the taxon suggests that byronia should have the priority. The epithet flavescens is invalid because the holotype on which the name...

The rocky shore of central Chile is heavily harvested by mariscadores de orilla and skin-divers, but their catches are not considered in the fishery statistics. The aim of the present paper is to estimate the intensity of human predation and annual catch of each of the species taken at Las Cruces, Central Chile. The activity pattern of both categor...

The antarctic fur seal Arctocephalus gazella was intensively exploited during the 19 th century in its distribution area. The ceasing of its exploitation, subsequent international protection, and the availability of food, mainly krill, due to the decreasing of whale production, brought about the recovery of the Antarctic fur seal specially in South...

We describe the basic ecology of two key-hole limpets, Fissurella crassa and Fissurella limbata, which are heavily harvested by coastal shellfishermen (mariscadores) at the rocky intertidal of central Chile. The ecological role of human predation on these species was assessed. Anthropic exclusion from a stretch of the rocky intertidal at Las Cruces...