South Pacific Coast Research Articles

Sustainable biorefinery of Ulva stenophylloides, a green-tide species from the South Pacific coast: A study on antioxidant, oligosaccharide, and ulvan extraction

Sustainable biorefinery of Ulva stenophylloides, a green-tide species from the South Pacific coast: A study on antioxidant, oligosaccharide, and ulvan extraction

Prevalence of injuries in a Caiman crocodilus chiapasius (Bocourt 1876) population from the South Pacific coast of Mexico

ABSTRACT Crocodilians injuries are indicators of their health and social interactions. We analyzed the prevalence and distribution of injuries in spectacled caiman (Caiman crocodilus chiapasius) from the Biosphere Reserve of La Encrucijada (BRLE) in relation to the habitat, size, and sex of individuals. We collected data on injuries in caimans captured during nocturnal surveys (2014–2022) in the estuary and swamps of the BRLE. We determined the sex of each caiman, measured their snout–vent length, and registered the type of injury and body region where injuries were detected. From all records, 102 of 301 caimans (33.9%) presented injuries and they were more likely to be injured in the estuary than in the swamps, probably due to the presence of a larger sympatric crocodile species in the estuary (Crocodylus acutus). Sex had no effect on the proportion of injured individuals, but larger caimans have a higher probability of being injured than smaller ones, explained by an ontogenetic change in the individuals’ behaviors. Habitat, sex, and size class of individuals do not influence the number of injuries on different body regions. The tail was the most injured body region (17.6% of individuals), followed by the abdomen (13.0%), back (12.6%), head (9.6%), and extremities (4.0%).

Gills de novo assembly reveals oxidative stress, unfolded protein, and immune response on red cusk-eel (Genypterus chilensis) under thermal stress

The heat waves on the South Pacific coast could lead to thermal stress in native fish. The red cusk-eel (Genypterus chilensis) is relevant for Chilean artisanal fisheries and aquaculture diversification. This study examined the effect of high-temperature stress in the gills of G. chilensis in control (14 °C) and high-temperature stress (19 °C) conditions. High-temperature stress induces a significant increase in gills cortisol levels. Additionally, oxidative damage was observed in gills (protein carbonylation and lipoperoxidation). RNA-seq data was used to build the first transcriptome assembly of gills in this species (23,656 annotated transcripts). A total of 1138 down-regulated and 1531 up-regulated transcripts were observed in response to high-temperature stress in gills. The enrichment analysis showed immune response and replication enriched processes (on down-regulated transcripts), and processes related to the folding of proteins, endoplasmic reticulum, and transporter activity (on up-regulated transcripts). The present study showed how gills could be affected by high-temperature stress.

Habitat fragmentation erodes taxonomic and functional diversity of waterbird communities of the South Pacific coast of Mexico

We characterize the taxonomic and functional diversity of waterbird communities in mangrove forests of 23 coastal lagoons in the southern Mexican Pacific coast, to evaluate the hypothesis of decline of taxonomic and functional richness of waterbird communities in the face of loss of natural habitat cover and increased fragmentation. We quantified patterns of land use cover, considering the heterogeneity of natural and anthropized vegetation cover as a proxy for human-caused fragmentation, and used generalized linear models to explore the relationship between these two covers with the taxonomic richness and functional richness of bird communities. Results show that both aspects of biodiversity positively relate to larger natural habitat areas, while higher fragmentation values have a negative effect on them. Our results suggest that habitat loss and fragmentation of vegetation cover negatively affect the diversity of waterbird communities and can compromise their link to ecosystem functioning processes in coastal lagoons, by decreasing their functional diversity.

Nonlinear time series analysis of coastal temperatures and El Niño–Southern Oscillation events in the eastern South Pacific

Abstract. We carry out a nonlinear time series analysis motivated by dynamical systems theory to investigate the links between temperatures on the eastern South Pacific coast, influenced by the Humboldt Current System, and El Niño–Southern Oscillation (ENSO) events. To this aim, we use a set of 16 oceanic and atmospheric temperature time series from Chilean coastal stations distributed between 18 and 45∘ S. The spectral analysis indicates periodicities that can be related to both internal and external forcing, involving not only ENSO, but also the Pacific Decadal Oscillation, the Southern Annual Mode, the Quasi-Biennial Oscillation and the lunar nodal cycle. The asymptotic neural network test for chaos based on the largest global Lyapunov exponent indicates that the temperature dynamics along the Chilean coast is not chaotic. We use local Lyapunov exponents to characterize the short-term stability of the series. Using a cross-entropy test, we find that two stations in northern Chile, one oceanic (Iquique) and one atmospheric (Arica), present a significant positive cross-dependence between local Lyapunov exponents and ENSO. Iquique is the station that presents the greater number of regional characteristics and correlates with ENSO differently from the rest. The unique large-scale study area, combined with time series from hitherto unused sources (Chilean naval records), reveals the nonlinear dynamics of climate variability in Chile.

Common patterns between dengue cases, climate, and local environmental variables in Costa Rica: A wavelet approach.

Dengue transmission poses significant challenges for public health authorities worldwide due to its susceptibility to various factors, including environmental and climate variability, affecting its incidence and geographic spread. This study focuses on Costa Rica, a country characterized by diverse microclimates nearby, where dengue has been endemic since its introduction in 1993. Using wavelet coherence and clustering analysis, we performed a time-series analysis to uncover the intricate connections between climate, local environmental factors, and dengue occurrences. The findings indicate that multiannual dengue frequency (3 yr) is correlated with the Oceanic Niño Index and the Tropical North Atlantic Index. This association is particularly prominent in cantons located along the North and South Pacific Coast, as well as in the Central cantons of the country. Furthermore, the time series of these climate indices exhibit a leading phase of approximately nine months ahead of dengue cases. Additionally, the clustering analysis uncovers non-contiguous groups of cantons that exhibit similar correlation patterns, irrespective of their proximity or adjacency. This highlights the significance of climate factors in influencing dengue dynamics across diverse regions, regardless of spatial closeness or distance between them. On the other hand, the annual dengue frequency was correlated with local environmental indices. A persistent correlation between dengue cases and local environmental variables is observed over time in the North Pacific and the Central Region of the country's Northwest, with environmental factors leading by less than three months. These findings contribute to understanding dengue transmission's spatial and temporal dynamics in Costa Rica, highlighting the importance of climate and local environmental factors in dengue surveillance and control efforts.

Latitudinal distribution of skeleton shrimps (Amphipoda, Caprellidae) in artificial habitats throughout the eastern South Pacific coast of Peru

ABSTRACT Biodiversity tends to decrease poleward and increase towards the equator. However, these patterns remain unknown for many invertebrate taxa throughout Peru's eastern South Pacific coast, particularly for caprellid crustaceans which are conspicuous in artificial habitats. Three biogeographical units have been proposed for the Peruvian coast: Panamic and Humboldt provinces with a transition zone in between, but a few invertebrates support this classification. We evaluated if the diversity of caprellids decreases towards high latitudes and if the assemblages of caprellids depicted the biogeographic zonation proposed for the Peruvian coast. From 15th to 31st October 2021, caprellids were collected from biofouling communities colonizing boat hulls, buoys, and ropes throughout the Peruvian coast (3.74°–17.99° S). The caprellid assemblage consisted on six species: Caprella penantis [sensu lato], C. penantis f. gibbosa, C. equilibra, C. scaura, Paracaprella pusilla, and Deutella venenosa. Overall, caprellids' abundance, species richness, and diversity decreased southwards. Specific caprellid assemblages showed affinities for each of the three biogeographical units. The dissimilarity of the caprellid assemblages increased at approximately every one degree of latitude. Although artificial substrates can alter biodiversity patterns, caprellids showed the canonical pattern of high diversity towards the equator and resembled the biogeographic zonation proposed for the Peruvian coast.

Controlled cultivation of different stages of Pyropia orbicularis (Rhodophyta; Bangiales) from the South Pacific coast

The species of the genus Pyropia have a diplohaplontic life cycle, in which there is a gametophytic phase (n) or blade, and a microscopic sporophytic phase (2n), known as conchocelis, as well as intermediate stages of development. Pyropia species, together with Porphyra species, belong to the group of the most commercialized and produced macroalgae worldwide, mainly due to their high nutritional value and high content of bioactive compounds with antioxidant and anti-inflammatory activity. The interest in cultivating and exploiting this marine resource has increased in recent years; nevertheless, despite the development of cultivation techniques and technologies for these species, there are still difficulties involved in their successful cultivation, mainly related to the great interspecific and intraspecific variability in the required culture conditions. In this work, we study the life cycle development of Pyropia orbicularis, a species endemic to the South Pacific, to determine the effect of abiotic culture parameters, such as the temperature and photoperiod, on the formation and development of early and late life cycle stages, such as conchocelis formation, cochoesporangial filaments, conchospore release and blade growth. Our results demonstrate that the conchocelis phase grew rapidly under 8:16 h (L:D) photoperiod conditions at both 15 °C and 20 °C. The lower temperatures favored the formation of conchosporangia and conchospores; the rate of their development was increased at 15 °C. The development of the blades in the suspended culture system was constant during the experimental period, generating blades of the same color and shape as those from natural populations. Our results reflect the adaptation of P. orbicularis to the seasonal environmental conditions it is exposed to and the importance of maintaining optimal abiotic parameters for the success of its culture. This work is the first to describe the full life cycle development of P. orbicularis under controlled conditions, which has important implications for commercial production.

Coleoptera associated with intermittent streams and their riparian zones in south coastal British Columbia

AbstractIntermittent streams that periodically cease surface flow have long been understudied in ecology and underrepresented in conservation policy. However, they currently account for 30–50% of the global river network, and that number is rising due to anthropogenic water extraction, land-use change, and climate change. We explored the Coleoptera biodiversity of the south Pacific coast region of British Columbia, Canada, using pitfall traps at perennial and naturally intermittent stream reaches, in shoreline, dry streambed, and riparian habitats, in both flowing (spring and early summer) and nonflowing (late summer) phases. We found that habitats around perennial reaches had significantly greater abundance of Coleoptera individuals than did those around intermittent reaches. However, neither habitat type nor flow regime was a significant predictor of taxon richness, and intermittent stream sites featured unique taxa that were not found near perennial streams. This aligns with recent results from other taxonomic groups; that is, finding that intermittent ecosystems can host high taxonomic diversity of Coleoptera, on par with or even greater than that of perennial streams. Because intermittent streams will likely become more prevalent within the global river network, a better understanding of how different species use these habitats is needed to inform appropriate biodiversity conservation efforts and flow management.

Using Bayesian networks to map winter habitat for mountain goats in coastal British Columbia, Canada

The mountain goat (Oreamnos americanus) is an iconic wildlife species of western North America that inhabits steep and largely inaccessible terrain in remote areas. They are at risk from human disturbance, genetic isolation, climate change, and a variety of other stressors. Managing populations is challenging and mountain goats are particularly difficult and expensive to inventory. As a result, biologists often rely on models to estimate the species’ abundance and distribution in remote areas. We used landscape characteristics evident at point locations of mountain goat visual observations, tracks, and telemetry locations, along with random locations, to learn the structure and parameters of a Bayesian network that predicted the suitability of habitats for mountain goats. We then used the model to map habitat suitability across 285,000 km2 of potential habitat in mountain ranges of the south and central Canadian Pacific coast. Steep slopes, forest cover characteristics, and snow depth were the important drivers. Modeling the system as a Bayesian network provided several advantages over more common regression methods because input variables were heterogenous (i.e., a mix of discrete and continuous), autocorrelated, and animals exhibited non-linear responses to landscape conditions. These common characteristics of ecological data routinely violate the assumptions of parametric linear models, which are commonly used to map habitat suitability from animal observations.

Chemical Diversity and Bioactivity of Marine Sponges of the Genus Oceanapia: A Review

: The marine sponges of the genus Oceanapia sp. is comprised of more than 50 species and are distributed in the seas around the tropical and subtropical regions. They are mainly found in the northern Indian oceans, Japan, and the south pacific coast. They are highly colored and known to be a rich source of various secondary metabolites, particularly, alkaloids. Several other secondary metabolites were also reported from this genus which include terpenes, sphingolipids, ceramides, cerebrosides, acetylenic acids, and thiocyanatins, etc. Many of these compounds isolated from this genus exhibited various biological properties including anticancer, antimicrobial, anti-HIV, ichthyotoxicity and nematocidal activities. Although several secondary metabolites have been reported from this genus, a dedicated review of the chemicals and biological activities of this genus is so far lacking. Keeping this in mind this review describes the various chemical entities isolated from the sponges of the genus Oceanapia detailing their chemical structures along with their reported biological properties.

Correction to: Efficiency drivers for the South Pacific West coast port terminals: a two-stage non-convex metafrontier dea approach

Correction to: Efficiency drivers for the South Pacific West coast port terminals: a two-stage non-convex metafrontier dea approach

Efficiency drivers for the South Pacific West coast port terminals: a two-stage non-convex metafrontier dea approach

We measure technical efficiency of Peruvian and Chilean port terminals, to evaluate the influence of certain contextual variables in the terminals’ efficiency levels. The sample includes 14 port terminals from 2004 to 2014. Due to the potential differences, we have estimated a DEA model in a non-convex metafrontier framework. Afterwards, we estimated all the regression models proposed in the literature that could be used to explain not only the technical efficiency estimated with respect to the metafrontier (TE*) but also each one of its components: the technical efficiency with respect to the group-specific frontier (TEk) and the technological gap ratio (TGR). Results are robust across models.

Non-timber forest product importance for rural household well-being in four coastal communities in Oaxaca, Mexico

Rural household livelihoods usually depend on the use of non-timber forest products (NTFPs) as a strategy for income diversification and survival. Thus, this research seeks to determine the role played by NTFPs at the household level. A survey was conducted with 212 households in four localities with a high degree of marginalization, located on the South Pacific coast of Mexico in Oaxaca State. The results show that, firstly, NTFPs are used by all households, even the wealthiest families, and that the most important products used are fuelwood and medicinal plants. Secondly, the findings indicate that the collection and self-consumption of fuelwood and medicinal plants by households with lower incomes generate savings of at least 20% of their total annual gross income. Thirdly, for the majority of the surveyed households (90%), NTFPs are perceived as important for their well-being. This could be due to traditional or cultural attachment to ancestral practices, such as the use of fuelwood for cooking traditional food and the collection of medicinal plants. Finally, NTFP use is a livelihood diversification strategy and promotes the objective and subjective well-being of rural households. Social and environmental policies need to consider the potential of NTFPs for poverty alleviation and rural development through sustainable use and coordinated actions.

A new species of Heterocotyle (Monogenea: Monocotylidae), a gill parasite of the diamond stingray Hypanus dipterurus (Myliobatiformes: Dasyatidae) from the Peruvian coastal zone

A new monogenean, Heterocotyle margaritae n. sp. (Monocotylidae: Heterocotylinae), is described based on specimens collected from the gills of the diamond stingray, Hypanus dipterurus (Jordan & Gilbert, 1880) (Myliobatiformes: Dasyatidae) captured off the South Pacific coast, Lima Region, Peru. Monogeneans were fixed in hot 4% formalin, observed and measured as permanent mounts stained with Gomori's trichrome, and mounted in Canada balsam. Drawings were made with the aid of a drawing tube. The new species is distinguished from all congeners mainly by having a funnel-shaped male copulatory organ, spatulate distally with lateral folds and by its club-shaped accessory piece. The most similar congener, H. americana Hargis, 1955, resemble H. margaritae n. sp. regarding the general structure of the male copulatory organ (funnel-shaped with an accessory piece). However, besides other features, the new species differ from H. americana by having an accessory piece without a dorsal button (vs an accessory piece with a dorsal button in H. americana). This is the first report of a member of Heterocotyle Scott, 1904 in the Southeastern Pacific Ocean. The present finding brings to 20 the number of known species of Heterocotyle, and represents the fifth described monogenean species from Hypanus dipterurus.

Spatio-temporal dynamics of Plasmodium falciparum transmission within a spatial unit on the Colombian Pacific Coast

As malaria control programmes concentrate their efforts towards malaria elimination a better understanding of malaria transmission patterns at fine spatial resolution units becomes necessary. Defining spatial units that consider transmission heterogeneity, human movement and migration will help to set up achievable malaria elimination milestones and guide the creation of efficient operational administrative control units. Using a combination of genetic and epidemiological data we defined a malaria transmission unit as the area contributing 95% of malaria cases diagnosed at the catchment facility located in the town of Guapi in the South Pacific Coast of Colombia. We provide data showing that P. falciparum malaria transmission is heterogeneous in time and space and analysed, using topological data analysis, the spatial connectivity, at the micro epidemiological level, between parasite populations circulating within the unit. To illustrate the necessity to evaluate the efficacy of malaria control measures within the transmission unit in order to increase the efficiency of the malaria control effort, we provide information on the size of the asymptomatic reservoir, the nature of parasite genotypes associated with drug resistance as well as the frequency of the Pfhrp2/3 deletion associated with false negatives when using Rapid Diagnostic Tests.

Espacio público y vendedores informales afrocolombianos en Cali, Colombia

El 25.5% de todos los afrodescendientes en Colombia residen en la ciudad de Cali, lo que representa el 26% de la población total de la ciudad. De esta manera, Cali es una de las ciudades con mayor población afrocolombiana del país. La ciudad ha sido el principal centro de atracción para las poblaciones migrantes de la costa del Pacífico Sur de Colombia en la que prevalece la población afrocolombiana. La venta informal en Cali es llevada a cabo principalmente por migrantes rurales y/o desplazados internos. En este artículo, me interesa saber si los afrocolombianos sufren una mayor marginalidad y discriminación como vendedores ambulantes que los auto identificados como mestizos y blancos o si, por el contrario, ambos grupos enfrentan niveles similares de discriminación. Por lo tanto, propongo averiguar si los cuerpos negros están marcados por discursos de indeseabilidad y crimen en los espacios públicos de esta ciudad. Adicionalmente, este fenómeno es entendido por los académicos urbanos, así como por el gobierno de Cali como una lucha de clases. Esta comprensión ratifica la invisibilidad de los cuerpos racializados negros en los discursos de igualdad. Muchos autores afirman que el problema actual en Colombia de reconocer la composición racial diversa de los vendedores informales y entender estas luchas sólo a través de las clases impide un discernimiento bien pensado de las realidades sociales y económicas que enfrentan los cuerpos racializados en los espacios públicos.

A Comparative Study of Geoelectric Signals Possibly Associated with the Occurrence of Two Ms > 7 EQs in the South Pacific Coast of Mexico

During past decades, several studies have suggested the existence of possible seismic electric precursors associated with earthquakes of magnitude . However, additional analyses are needed to have more reliable evidence of pattern behavior prior to the occurrence of a big event. In this article we report analyses of self-potential records during approximately two years in three electro-seismic stations in Mexico located at Acapulco, Guerrero; Petatlán, Guerrero and Pinotepa Nacional, Oaxaca. On 18 April 2014 an earthquake occurred near our Petatlán station. Our study shows two notable anomalies observed in the behavior of the Fourier power spectrum of for ultra low frequency ULF-range, and the transition of the -exponent of the detrended fluctuation analysis of the time series from uncorrelated to correlated signals. These anomalies lasted approximately three and a half months before the main shock. We compare this electric pattern with another electric signal we reported associated with an that occurred on 14 September 1995 at Guerrero state, Mexico. Our characterization of the anomalies observed in both signals point out similar features that enrich our knowledge about precursory phenomena linked to the occurrence of earthquakes of magnitude .

Community resilience and urban planning in tsunami-prone settlements in Chile.

Urban planning can serve to minimise the effects of a tsunami and enhance community resilience. This study explores to what extent urban planning has addressed tsunami resilience in four villages on Chile's South Pacific coast, each of which was struck by tsunamis in 1960, 2010, and 2015. Through a detailed policy review and semi-structured interviews with residents, this paper analyses whether tsunami mitigation policies were incorporated into regional and local planning tools. It finds that although the government proposed relocation to tsunami-safe areas after the tsunami of 1960, urban development continued mainly in tsunami inundation zones-in the context of weak local planning frameworks and in the absence of community participation. In only one of the four case studies did participatory planning bring about the relocation of an entire village to a safe location. This paper concludes that incorporating participatory risk zone planning into urban planning enhances tsunami resilience.

Redescription of Rhadinorhynchus trachuri Harada, 1935 (Acanthocephala: Rhadinorhynchidae) from Marine Fish in Vietnam and California with a Discussion of its Zoogeography.

Rhadinorhynchus trachuri Harada, 1935 is probably one of the most widely distributed acanthocephalans in the world, but the least known taxonomically. This report fills the large gap of knowledge about its taxonomy, host relationships, and worldwide distribution in marine fishes of both sides of the Pacific Ocean and the connecting Indian Ocean. To revisit the taxonomy of this species, provide a more complete morphological description and expand our knowledge about its morphological identity and variations and elaborate on its worldwide zoogeography; accounting for its worldwide distribution based on new collections, museum specimens, and on published reports. Specimens from Vietnam were processed, identified, and documented using standard techniques. Specimens of R. trachuri were studied from three species of fish in three families, Auxis thazard (Lacépède) (Scombridae), Megalaspis cordyla (Linn.) (Carangidae), and Tylosurus sp. (Belonidae) in Nha Trang and Binh Thuan in the south Pacific coast of Vietnam and additional museum specimens mostly from salmonids from the Pacific coast of California were also studied. Extensive research was conducted on published records of R. trachuri and its marine fish hosts worldwide. Specimens of R. trachuri are characterized by cylindrical trunk with anterior rings of spines and posterior ventral and lateral spines, a proboscis usually with 12 hook rows each with 19-24 hooks, variable position of testes, and a long uterus, uterine bell attached to the dorsal trunk wall, rounded vagina, and unusually dorsal gonopore. The hosts and geographical distribution of R. trachuri suggest a northern linkage of infections between the Asian and American Pacific populations across the Bering Sea involving salmonid fishes and a southern linkage through the Indian Ocean involving Carangid fishes. Other hosts involved in the cycling and distribution of infections are also discussed with some definitive hosts also serving as paratenic hosts. This is the first complete description about R. trachuri and the first comprehensive accounting of its worldwide distribution in 19 species of marine fish in seven families. Considerable intraspecific variability related to geographical restrictions, intermediate and definitive host specificity and distribution, and host feeding behavior was documented.