Assessing the ecological quality status of macrobenthic communities in a marine terminal of liquefied natural gas in Peru.

Macrobenthic organisms are useful bioindicators to assess ecological quality status. On the south-central coast of Peru (13°15.15'S, 76°18.5'W), a Liquefied Natural Gas (LNG) marine terminal has been operating since 2010. We investigated the macrobenthic communities and sediment parameters from 2011 to 2020 to evaluate the ecological quality status in the surrounding area of the marine terminal, using the AZTI Marine Biotic Index (AMBI) and its multivariate version (M-AMBI). We analyzed the diversity and community composition of macrobenthic invertebrates and the physico-chemical parameters of the sediment from 29 sampling sites, ranging from 0 to 15m depth. The sampling design considered: the direct influence zone ("DIZ", surroundings of the marine terminal), and northern (NCZ) and southern (SCZ) control zones. Our results indicated that abundance was high at SCZ and decreased with depth. Species richness and diversity were high at DIZ and NCZ, respectively, and increased up to 10m but dropped at 15m. High sand content was recorded in shallow depths, while in deeper areas and DIZ, mud and organic matter increased and redox potential was negative. AMBI indicated a "slightly disturbed" status in general, while M-AMBI indicated "good" or "moderate" status at depths ≤ 12m, and "poor" status at 15m. Overall, the season/year factor was not important, and variables were mostly significantly different across depths. Redox potential and organic matter were correlated with M-AMBI at 15m. In general, our results indicate an acceptable ecological quality surrounding the marine terminal, likely because the study area is not influenced by an important input of an anthropogenic stressor. This study highlights the importance of monitoring benthic communities in the surroundings of human-made structures and the use of ecological quality indices for understanding potential impacts.

DNA barcoding in the Southeast Pacific marine realm: Low coverage and geographic representation despite high diversity.

The Southeast Pacific comprises two Large Marine Ecosystems, the Pacific Central-American Coastal and the Humboldt Current System; and is one of the less well known in the tropical subregions in terms of biodiversity. To address this, we compared DNA barcoding repositories with the marine biodiversity species for the Southeast Pacific. We obtained a checklist of marine species in the Southeast Pacific (i.e. Colombia, Ecuador, Chile, and Peru) from the Ocean Biodiversity Information System (OBIS) database and compared it with species available at the Barcoding of Life Data System (BOLD) repository. Of the 5504 species records retrieved from OBIS, 42% of them had at least one registered specimen in BOLD (including specimens around the world); however, only 4.5% of records corresponded to publicly available DNA barcodes including specimens collected from a Southeast Pacific country. The low representation of barcoded species does not vary much across the different taxonomic groups or within countries, but we observed an asymmetric distribution of DNA barcoding records for taxonomic groups along the coast, being more abundant for the Humboldt Current System than the Pacific Central-American Coastal. We observed high-level of barcode records with Barcode Index Number (BIN) incongruences, particularly for fishes (Actinopterygii = 30.27% and Elasmobranchii = 24.71%), reflecting taxonomic uncertainties for fishes, whereas for Invertebrates and Mammalia more than 85% of records were classified as data deficient or inadequate procedure for DNA barcoding. DNA barcoding is a powerful tool to study biodiversity, with a great potential to increase the knowledge of the Southeast Pacific marine biodiversity. Our results highlight the critical need for increasing taxonomic sampling effort, the number of trained taxonomic specialists, laboratory facilities, scientific collections, and genetic reference libraries.

Population recovery changes population composition at a major southern Caribbean juvenile developmental habitat for the green turtle, Chelonia mydas.

Understanding the population composition and dynamics of migratory megafauna at key developmental habitats is critical for conservation and management. The present study investigated whether differential recovery of Caribbean green turtle (Chelonia mydas) rookeries influenced population composition at a major juvenile feeding ground in the southern Caribbean (Lac Bay, Bonaire, Caribbean Netherlands) using genetic and demographic analyses. Genetic divergence indicated a strong temporal shift in population composition between 2006-2007 and 2015-2016 (ϕST = 0.101, P < 0.001). Juvenile recruitment (<75.0 cm straight carapace length; SCL) from the north-western Caribbean increased from 12% to 38% while recruitment from the eastern Caribbean region decreased from 46% to 20% between 2006-2007 and 2015-2016. Furthermore, the product of the population growth rate and adult female abundance was a significant predictor for population composition in 2015-2016. Our results may reflect early warning signals of declining reproductive output at eastern Caribbean rookeries, potential displacement effects of smaller rookeries by larger rookeries, and advocate for genetic monitoring as a useful method for monitoring trends in juvenile megafauna. Furthermore, these findings underline the need for adequate conservation of juvenile developmental habitats and a deeper understanding of the interactions between megafaunal population dynamics in different habitats.

Macrobenthic fauna from an upwelling coastal area of Peru (Warm Temperate South-eastern Pacific province -Humboldtian ecoregion).

BACKGROUND: A total of 162 species and subspecies of marine macroinvertebrates were recorded in the submerged soft and hard substrates around the PERU LNG marine terminal and surrounding area, in the central coast of Peru, 167 km south of Lima, Peru. The collection of specimens was carried out from June 2011 to June 2015 as part of the research studies conducted by the Biodiversity Monitoring and Assessment Program (BMAP) around the marine terminal. The area is part of the Humboldt Current Large Marine Ecosystem, one of the most important upwelling systems in the world. NEW INFORMATION: We identified specimens belonging to 83 families and seven phyla. The list was assembled from the taxonomic identifications made by the BMAP. We identified species and subspecies belonging to phyla Annelida, Arthropoda, Brachiopoda, Cnidaria, Echinodermata, Bryozoa and Mollusca. Phyla Annelida (60 spp.), Arthropoda (47 spp.)and Mollusca (45 spp.) exhibited the largest number of species.

Fish DNA barcoding around large marine infrastructure for improved biodiversity assessment and monitoring.

Accurate species-level identification is pivotal for environmental assessments and monitoring. The PERU LNG terminal is composed of large marine infrastructure located on the central coast of Peru. Since construction, taxonomically challenging species such as drum fishes (Sciaenidae) have been attracted to the new hard-bottom habitat. We conducted a DNA barcoding study to investigate fish diversity and constructed a DNA barcode reference library. We examined 56 vouchered specimens and identified 24 unique species. Intra- and interspecific divergence estimates ranged between 0 and 0.64% and 11 and 35.5%, respectively. We assessed the efficiency of the reference library to identify 29 non-vouchered specimens. We had 82.5% efficiency by using both our reference library (n = 17) and GenBank (n = 24). We highlight the importance of implementing molecular barcoding for complementing biodiversity assessments in marine environments. This study represents a first step towards generating a comprehensive DNA barcode reference library for marine fishes in Peru.

First record of hybridization between green Chelonia mydas and hawksbill Eretmochelys imbricata sea turtles in the Southeast Pacific.

Hybridization among sea turtle species has been widely reported in the Atlantic Ocean, but their detection in the Pacific Ocean is limited to just two individual hybrid turtles, in the northern hemisphere. Herein, we report, for the first time in the southeast Pacific, the presence of a sea turtle hybrid between the green turtle Chelonia mydas and the hawksbill turtle Eretmochelys imbricata. This juvenile sea turtle was captured in northern Peru (4°13'S; 81°10'W) on the 5(th) of January, 2014. The individual exhibited morphological characteristics of C. mydas such as dark green coloration, single pair of pre-frontal scales, four post-orbital scales, and mandibular median ridge, while the presence of two claws in each frontal flipper, and elongated snout resembled the features of E. imbricata. In addition to morphological evidence, we confirmed the hybrid status of this animal using genetic analysis of the mitochondrial gene cytochrome oxidase I, which revealed that the hybrid individual resulted from the cross between a female E. imbricata and a male C. mydas. Our report extends the geographical range of occurrence of hybrid sea turtles in the Pacific Ocean, and is a significant observation of interspecific breeding between one of the world's most critically endangered populations of sea turtles, the east Pacific E. imbricata, and a relatively healthy population, the east Pacific C. mydas.

Fast growing, healthy and resident green turtles (Chelonia mydas) at two neritic sites in the central and northern coast of Peru: implications for conservation.

In order to enhance protection and conservation strategies for endangered green turtles (Chelonia mydas), the identification of neritic habitats where this species aggregates is mandatory. Herein, we present new information about the population parameters and residence time of two neritic aggregations from 2010 to 2013; one in an upwelling dominated site (Paracas ∼14°S) and the other in an ecotone zone from upwelling to warm equatorial conditions (El Ñuro ∼4°S) in the Southeast Pacific. We predicted proportionally more adult individuals would occur in the ecotone site; whereas in the site dominated by an upwelling juvenile individuals would predominate. At El Ñuro, the population was composed by (15.3%) of juveniles, (74.9%) sub-adults, and (9.8%) adults, with an adult sex ratio of 1.16 males per female. Times of residence in the area ranged between a minimum of 121 and a maximum of 1015 days (mean 331.1 days). At Paracas the population was composed by (72%) of juveniles and (28%) sub-adults, no adults were recorded, thus supporting the development habitat hypothesis stating that throughout the neritic distribution there are sites exclusively occupied by juveniles. Residence time ranged between a minimum of 65 days and a maximum of 680 days (mean 236.1). High growth rates and body condition index values were estimated suggesting healthy individuals at both study sites. The population traits recorded at both sites suggested that conditions found in Peruvian neritic waters may contribute to the recovery of South Pacific green turtles. However, both aggregations are still at jeopardy due to pollution, bycatch and illegal catch and thus require immediate enforcing of conservation measurements.

Shark fisheries in the Southeast Pacific: A 61-year analysis from Peru.

Peruvian waters exhibit high conservation value for sharks. This contrasts with a lag in initiatives for their management and a lack of studies about their biology, ecology and fishery. We investigated the dynamics of Peruvian shark fishery and its legal framework identifying information gaps for recommending actions to improve management. Further, we investigated the importance of the Peruvian shark fishery from a regional perspective. From 1950 to 2010, 372,015 tons of sharks were landed in Peru. From 1950 to 1969, we detected a significant increase in landings; but from 2000 to 2011 there was a significant decrease in landings, estimated at 3.5% per year. Six species represented 94% of landings: blue shark ( Prionace glauca), shortfin mako ( Isurus oxyrinchus), smooth hammerhead ( Sphyrna zygaena), common thresher ( Alopias vulpinus), smooth-hound ( Mustelus whitneyi) and angel shark ( Squatina californica). Of these, the angel shark exhibits a strong and significant decrease in landings: 18.9% per year from 2000 to 2010. Peru reports the highest accumulated historical landings in the Pacific Ocean; but its contribution to annual landings has decreased since 1968. Still, Peru is among the top 12 countries exporting shark fins to the Hong Kong market. Although the government collects total weight by species, the number of specimens landed as well as population parameters (e.g. sex, size and weight) are not reported. Further, for some genera, species-level identification is deficient and so overestimates the biomass landed by species and underestimates the species diversity. Recently, regional efforts to regulate shark fishery have been implemented to support the conservation of sharks but in Peru work remains to be done.

Shark tales: a molecular species-level phylogeny of sharks (Selachimorpha, Chondrichthyes).

Sharks are a diverse and ecologically important group, including some of the ocean's largest predatory animals. Sharks are also commercially important, with many species suffering overexploitation and facing extinction. However, despite a long evolutionary history, commercial, and conservation importance, phylogenetic relationships within the sharks are poorly understood. To date, most studies have either focused on smaller clades within sharks, or sampled taxa sparsely across the group. A more detailed species-level phylogeny will offer further insights into shark taxonomy, provide a tool for comparative analyses, as well as facilitating phylogenetic estimates of conservation priorities. We used four mitochondrial and one nuclear gene to investigate the phylogenetic relationships of 229 species (all eight Orders and 31 families) of sharks, more than quadrupling the number of taxon sampled in any prior study. The resulting Bayesian phylogenetic hypothesis agrees with prior studies on the major relationships of the sharks phylogeny; however, on those relationships that have proven more controversial, it differs in several aspects from the most recent molecular studies. The phylogeny supports the division of sharks into two major groups, the Galeomorphii and Squalimorphii, rejecting the hypnosqualean hypothesis that places batoids within sharks. Within the squalimorphs the orders Hexanchiformes, Squatiniformes, Squaliformes, and Pristiophoriformes are broadly monophyletic, with minor exceptions apparently due to missing data. Similarly, within Galeomorphs, the orders Heterodontiformes, Lamniformes, Carcharhiniformes, and Orectolobiformes are broadly monophyletic, with a couple of species 'misplaced'. In contrast, many of the currently recognized shark families are not monophyletic according to our results. Our phylogeny offers some of the first clarification of the relationships among families of the order Squaliformes, a group that has thus far received relatively little phylogenetic attention. Our results suggest that the genus Echinorhinus is not a squaliform, but rather related to the saw sharks, a hypothesis that might be supported by both groups sharing 'spiny' snouts. In sum, our results offer the most detailed species-level phylogeny of sharks to date and a tool for comparative analyses.

Dispersal, recruitment and migratory behaviour in a hawksbill sea turtle aggregation.

We investigated the dispersal, recruitment and migratory behaviour of the hawksbill sea turtle (Eretmochelys imbricata), among different life-history stages and demographic segments of the large hawksbill turtle aggregation at Mona Island, Puerto Rico. There were significant differences in both mitochondrial DNA (mtDNA) haplotype diversity and haplotype frequencies among the adult males, females and juveniles examined, but little evidence for temporal heterogeneity within these same groups sampled across years. Consistent with previous studies and the hypothesis of strong natal homing, there were striking mtDNA haplotype differences between nesting females on Mona Island and nesting females in other major Caribbean rookeries. Breeding males also showed strong, albeit weaker, genetic evidence of natal homing. Overall, Bayesian mixed-stock analysis suggests that Mona Island was the natal rookery for 79% (65-94%) of males in the aggregation. In contrast, the Mona Island rookery accounted for only a small subset of the new juvenile recruits to the foraging grounds or in the population of older juvenile hawksbills turtles on Mona. Instead, both new recruits and the older juvenile hawksbill turtles on Mona more likely recruited from other Caribbean rookeries, suggesting that a mechanism besides natal homing must be influencing recruitment to feeding habitats. The difference in the apparent degree of natal homing behaviour among the different life-history stages of hawksbill turtles at Mona Island underscores the complexity of the species' life-history dynamics and highlights the need for both local and regional conservation efforts.

Isolation and characterization of novel microsatellites from the critically endangered hawksbill sea turtle (Eretmochelys imbricata).

We isolated and characterized 12 microsatellite loci from the hawksbill sea turtle (Eretmochelys imbricata). The loci exhibited a variable number of alleles that ranged from three to 14 with an average observed heterozygosity of 0.70 (SD 0.18) across 40 hawksbill turtles from the Caribbean. The polymorphism exhibited individually and in combination makes them suitable for fine-scale genetic studies. In particular, the low probability of identity and high paternity exclusion of these markers makes them highly useful for parentage and relatedness studies. These new markers greatly increase the power of genetic studies directed towards the conservation of this endangered species.