Explore the vast range of titles available.

Defining priority areas and risk evaluation is of utmost relevance for endangered species` conservation. For the blue whale ( Balaenoptera musculus ), we aim to assess environmental habitat selection drivers, priority areas for conservation and overlap with vessel traffic off northern Chilean Patagonia (NCP). For this, we implemented a single-step continuous-time correlated-random-walk model which accommodates observational error and movement parameters variation in relation to oceanographic variables. Spatially explicit predictions of whales’ behavioral responses were combined with density predictions from previous species distribution models (SDM) and vessel tracking data to estimate the relative probability of vessels encountering whales and identifying areas where interaction is likely to occur. These estimations were conducted independently for the aquaculture, transport, artisanal fishery, and industrial fishery fleets operating in NCP. Blue whale movement patterns strongly agreed with SDM results, reinforcing our knowledge regarding oceanographic habitat selection drivers. By combining movement and density modeling approaches we provide a stronger support for purported priority areas for blue whale conservation and how they overlap with the main vessel traffic corridor in the NCP. The aquaculture fleet was one order of magnitude larger than any other fleet, indicating it could play a decisive role in modulating potential negative vessel-whale interactions within NCP.

Aim: Species distribution models are useful tools for depicting important habitat, assessing abundance and orienting conservation efforts. For small populations in poorly studied ecosystems, available data are often scarce and patchy. To overcome this limitation, we aim to evaluate the use of different data types within a hierarchical Bayesian framework with the goal of modelling the abundance and distribution of a small and highly migratory population of blue whale (BW, Balaenoptera musculus) summering in Chilean Northern Patagonian (CNP). Location: CNP, Eastern South Pacific (ESP). Methods: We constructed a Bayesian hierarchical species distribution Model (HSDM), combining a binomial N-mixture model used to model BW groups counts in line-transect data (2009, 2012 and 2014) with a logistic regression for modelling presence-availability data (2009-2016), allowing both models to share covariate parameters for borrowing strength in estimations. Results: Distance to areas of high chlorophyll-a concentration during spring before summering season (AHCC-s) was the most important and consistent explanatory variable for assessing BW abundance and distribution in CNP. Incorporating accessorial presence-only data reduced uncertainty in parameters estimation when comparing with a model using only line-transect data, although other covariates of secondary importance failed to be retained in this model. Main conclusions: Our results remark the capability of HSDM for integrating different data types providing a potential powerful tool when data are limited and heterogeneous. Results indicate that AHCC-s, and possibly thermal fronts, could modulate BW abundance and distribution patterns in CNP. Preliminary model-based delimitations of possible priority conservation areas for BW in CNP overlap with highly used vessel navigation routes and areas destined to aquaculture.

Mechanisms that reliably and efficiently guide practitioners to find relevant evidence are urgent for conservation decision‐making in Chilean Patagonia. The objective of this study was to systematically collect, characterize, and synthesize the extensive evidence about conservation knowledge in Chilean Patagonia focusing on the impacts of global change drivers on ecosystems and human–nature relationships, identifying knowledge gaps, and providing policy recommendations. The quality of the evidence was assessed through a predefined level‐of‐evidence hierarchy scale, applied to a sample of the studies reviewed. We compiled ~1000 studies documenting that evidence focusing on terrestrial and marine ecosystems has grown exponentially. For terrestrial ecosystems, most studies have addressed climate change, habitat change, and invasive species; while for marine ecosystems, studies have focused on pollution, invasive species, and habitat change. We identified that an important gap is the study of the social dimensions of conservation, and future efforts should focus on incorporating traditional and local knowledge as this can help point the way to ecosystem conservation. The appraisal of the quality of the evidence showed that ~80% of the sample represented reliable evidence with underlying data and an experimental design. Enhanced efforts to deliver this evidence to decision‐makers in a user‐friendly format for evidence uptake in conservation policy are urgent. In this review, we provide a tool that can help practitioners to find evidence reliably to improve decision‐making for the conservation of ecosystems in Chilean Patagonia. Mechanisms that guide practitioners to find the evidence reliably and efficiently are urgent for conservation decision making in Chilean Patagonia that has more than half of its territory remaining and protected. The evidence about conservation knowledge was systematically characterized and synthesized in Chilean Patagonia, identifying knowledge gaps and providing policy recommendations.

We reviewed available information on seabirds inhabiting Easter Island, Salas y Gómez Island and Desventuradas Islands and their adjacent waters through an analysis of published and grey literature. Results obtained indicate that a total of 37 species are present in the study area and that, among the orders represented, the Procellariiformes and Charadriiformes are the dominant taxa (29 species). Moreover, the family Procellariidae is represented by 13 species and Laridae by 7 species. There has been an increase in new records over the past six years but no systematic studies have been developed. The need for further research that focuses on ecological aspects and anthropogenic impacts is critical in order to develop adequate conservation strategies.

The Humboldt Current Ecosystem (HCE) is one of the most productive marine ecosystems, sustaining one of the largest fishing industries in the world. Although several species of cetaceans are known to inhabit these productive waters, quantitative assessments of their abundance and distribution patterns are scarce and patchy. Here, we present the first abundance and distribution estimates for fin whale ( Balaenoptera physalus ), southeast Pacific blue whales ( Balaenoptera musculus ), sperm whale ( Physeter macrocephalus ), dusky dolphin ( Lagenorhynchus obscurus ), and common dolphin ( Delphinus spp.) in the entire Chilean portion of the HCE. Line transect surveys were conducted during 2016–2021 between 18° S and 41° S and up to ~ 200 km offshore, and data were analyzed using distance sampling methods. Group counts were modelled as a function of environmental variables using single step Bayesian Binomial N-mixture model (BNMM), which allows full uncertainty propagation between model components. By using spatially explicit predictions of cetacean densities and observed vessel densities in the HCE, we provide quantitative assessments on the relative probability of cetaceans encountering vessels (RPCEV). Dusky dolphin and fin whale showed the largest distribution overlap with industrial and artisanal fishery fleets. Our results highlight areas where effort should be prioritized to address the extant but unquantified negative interactions between vessels and cetaceans in Chilean HCE.

The Chilean oceanic islands Easter Island (Rapa Nui) and Salas y Gómez Island (Motu Motiro Hiva) have received little attention with regards to basic marine mammal investigations. Here we review and update available information on the status of marine mammals in this area from different sources, including published accounts, local interviews and two recent expeditions. We also provide detailed accounts for each confirmed family or species, including historical data from published archaeological studies and whalers' logbooks from the 18th to the 20th centuries. Results indicate that a total of five marine mammal families (Balaenopteridae, Physeteridae, Ziphiidae, Delphinidae and Phocidae) have been confirmed within the study area, representing two mammalian orders (Cetartiodactyla and Carnivora). Within these, twelve species are known to occur: blue whale (Balaenoptera musculus), unidentified minke whale (Balaenoptera bonaerensis or B. acutorostrata), humpback whale (Megaptera novaeangliae), sperm whale (Physeter macrocephalus), Cuvier's beaked whale (Ziphius cavirostris), Blainville's beaked whale (Mesoplodon densirostris), false killer whale (Pseudorca crassidens), unidentified pilot whale (Globicephala sp.), bottlenose dolphin (Tursiops truncatus), common dolphin (Delphinus sp.), southern elephant seal (Mirounga leonina) and leopard seal (Hydrurga leptonyx). We discuss the implications of some of most noteworthy records and make a plea for further studies to improve our knowledge of these top predators in one of the most isolated places in the world.

A decrease in the frequency of two southeast Pacific blue whale song types was examined over decades, using acoustic data from several different sources in the eastern Pacific Ocean ranging between the Equator and Chilean Patagonia. The pulse rate of the song units as well as their peak frequency were measured using two different methods (summed auto-correlation and Fourier transform). The sources of error associated with each measurement were assessed. There was a linear decline in both parameters for the more common song type (southeast Pacific song type n.2) between 1997 to 2017. An abbreviated analysis, also showed a frequency decline in the scarcer southeast Pacific song type n.1 between 1970 to 2014, revealing that both song types are declining at similar rates. We discussed the use of measuring both pulse rate and peak frequency to examine the frequency decline. Finally, a comparison of the rates of frequency decline with other song types reported in the literature and a discussion on the reasons of the frequency shift are presented.

The Atlantic sector of the Southern Ocean (ASSO) has one of the highest densities of Antarctic krill ( Euphausia superba ) compared to other polar and subpolar regions, which attracts migratory baleen whale species to aggregate in this area for feeding. Humpback whales ( Megaptera novaeangliae ) also sing extensively while on the Southern Ocean feeding grounds which allows for the exploration of song similarity between feeding grounds and breeding populations which helps to understand population mixing. The results of comparative song analyses between the ASSO and the Ecuadorian and Brazilian breeding populations and recordings from the Chilean, South African and Namibian migration routes/mid-latitude feeding grounds revealed that individuals from at least three humpback whale breeding populations most likely migrate to shared feeding grounds in the ASSO. Humpback whales from different populations potentially mix at different times (i.e., years) at feeding hotspots in variable locations. The ASSO seems to provide sufficient prey resources and seems to present an important area for both cultural and maybe even genetic exchange between populations supporting the maintenance of large gene pools. Assuming that multi-population feeding hotspots are also suitable habitat for krill and other krill-dependent predators, these areas in the ASSO should be carefully managed integrating population, ecosystem and fisheries management.

The most traditional scheme for migration among baleen whales comprises yearly migrations between productive waters at high latitude summer feeding grounds and warmer waters at lower latitudes where whales calve and mate, but rarely feed. Evidence indicates, however, that large departures from this scheme exist among populations and individuals. Furthermore, for some populations there is virtually no information on migratory pathways and destinations. Such is the case of Chilean blue whales throughout the Eastern South Pacific; hence, the goal of this study was to assess its migratory behavior. Dedicated marine surveys and satellite tagging efforts were undertaken during the austral summer and early autumn on blue whale feeding grounds off Chilean Northern Patagonia (CNP) during 2013, 2015 and 2016. Positional data derived from satellite tags regarding movement patterns and behavior were analyzed using Bayesian switching first-difference correlated random walk models. We instrumented 10 CNP blue whales with satellite transmitters and documented individual variation in departure time, northbound migratory routes and potential wintering grounds. The onset of migration occurred from mid/late austral autumn to well into the austral winter. Blue whales moved in various directions, but ultimately converged toward a general NW movement direction along a wide corridor exceeding 2,000 km. Area-Restricted Search behavior was exhibited within fjords and channels of CNP and also South of Galapagos Archipelago (GA) and northern Peru, but never during migration. Interestingly, dive profiles for one whale that reached GA showed a sharp and consistent increase in depth north of 5°S and extreme deep dives of up to 330 m. Information derived from satellite tagged blue whales in this study is the first of its kind off the Eastern Southern Pacific. Our results provide valuable information on their migratory timing, routes and behavior on their northbound migration, particularly regarding the varied migratory plasticity for this particular population. Our results also highlight the first record of two complete migratory paths between CNP and GA and strengthen the hypothesis that GA waters correspond to a potential wintering destination for CNP blue whales. We further hypothesize that this area might be selected because of its biological productivity, which could provide feeding opportunities during the breeding season. Our results suggest that special efforts should be put forward to identify blue whale critical areas and understand key behavioral aspects in order to provide the basis for their conservation on a regional context (i.e., reducing potential ship strike and promote Marine Protected Area (MPA) implementation in Chile, Ecuador and Peru). Indeed, we suggest joint blue whale conservation efforts at the regional level in order to identify and determine potential threats and impacts and, most importantly, implement prospective management actions.

It is generally assumed that species with low population sizes have lower genetic diversities than larger populations and vice versa. However, this would not be the case for long‐lived species with long generation times, and which populations have declined due to anthropogenic effects, such as the blue whale (Balaenoptera musculus). This species was intensively decimated globally to near extinction during the 20th century. Along the Chilean coast, it is estimated that at least 4288 blue whales were hunted from an apparently pre‐exploitation population size (k) of a maximum of 6200 individuals (Southeastern Pacific). Thus, here, we describe the mtDNA (control region) and nDNA (microsatellites) diversities of the Chilean blue whale aggregation site in order to verify the expectation of low genetic diversity in small populations. We then compare our findings with other blue whale aggregations in the Southern Hemisphere. Interestingly, although the estimated population size is small compared with the pre‐whaling era, there is still considerable genetic diversity, even after the population crash, both in mitochondrial (N = 46) and nuclear (N = 52) markers (Hd = 0.890 and Ho = 0.692, respectively). Our results suggest that this diversity could be a consequence of the long generation times and the relatively short period of time elapsed since the end of whaling, which has been observed in other heavily‐exploited whale populations. The genetic variability of blue whales on their southern Chile feeding grounds was similar to that found in other Southern Hemisphere blue whale feeding grounds. Our phylogenetic analysis of mtDNA haplotypes does not show extensive differentiation of populations among Southern Hemisphere blue whale feeding grounds. The present study suggests that although levels of genetic diversity are frequently used as estimators of population health, these parameters depend on the biology of the species and should be taken into account in a monitoring framework study to obtain a more complete picture of the conservation status of a population. It is generally assumed that species with low population sizes have lower genetic diversities than larger populations. However, this would not be the case of long‐lived species with long generation times, and which populations have declined due to anthropogenic effects. We find no relationship between genetic diversity and population size in probably one of the most endangered species on seas, the blue whale (Balaenoptera musculus).