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Marine turtles are a group of imperiled marine megafauna particularly vulnerable to anthropogenic stressors. Most long‐term studies of marine turtles are based on nesting surveys which focus on numbers of eggs, hatchlings, and nesting females. However, we know less about long‐term abundance trends of immature and adult turtles in the marine environment. To address this data gap, we examined records from 35,000 underwater visual census (UVC) dives (1993–2019) and short‐term in‐water turtle survey data (2009–2014) at Cocos Island, Costa Rica. During UVCs, trained divemasters from UnderSea Hunter recorded observations of two species of marine turtles—green Chelonia mydas and hawksbill Eretmochelys imbricata. Our short‐term in‐water surveys revealed that most turtles at Cocos are greens, but both immature and mature greens occur at Cocos. We analyzed long‐term UVC data using a hierarchical modeling approach and we modeled a 26% decrease in the relative abundance of turtles observed on dives each year. Our model also revealed potential interactions between tiger sharks and turtles, finding that for each additional tiger shark present during a dive, the predicted relative abundance of turtles decreased by 43%. Lastly, our model suggested the influence of environmental variation on marine turtle relative abundance; a 1°C increase in sea surface temperature (SST) decreased the predicted relative abundance of turtles by 7%. Our results suggest that marine turtles are sensitive to long‐term environmental and oceanographic changes, and potentially avoid certain areas to reduce exposure to tiger sharks. Given our study area is already protected, there needs to be more focus on protecting adult turtles during their movements across the Eastern Tropical Pacific. Our work also highlights the importance of long‐term underwater surveys to monitor adult turtles. [ABSTRACT FROM AUTHOR]

Rough‐toothed dolphins (Steno bredanensis) typically inhabit deep oceanic waters from tropical to temperate waters worldwide. However, their ecology and behavior remain poorly understood. We investigated site fidelity and social structure of rough‐toothed dolphins using photo‐identification data collected between 2014 and 2022 in the continental shelf waters of the southwestern coast of Mexico. A total of 133 groups of rough‐toothed dolphins were recorded. Mean group size was 4.9 individuals (SD = 4.5), and dolphins were encountered in waters of a mean depth of 110 m (SD = 188). Of 228 individuals identified, 55% were observed once, 39% were seen between two and four times, and 6% were seen five times or more. Site fidelity analysis suggests three levels of site fidelity: transients, occasional visitors, and regular visitors, which are likely to affect the social structure. Through network analysis, nonrandom social patterns were identified (S = 1.25 ± 0.26) and dolphins exhibited both preferences and avoidances of social partners. Cluster analysis suggested significant divisions within the population (Q = 0.43 ± 0.05). Despite limitations related to sample size and design, this preliminary study suggests that rough‐toothed dolphins are best characterized by a fission‐fusion society, which is similar to most coastal delphinid populations. [ABSTRACT FROM AUTHOR]

The decline of coral reefs has increased interest in ecological restoration. Due to the scarcity of coral gardening projects in the Eastern Tropical Pacific, improving our understanding of such techniques is key. We report the results of coral gardening using the branching Pocillopora spp. and massive coral species (Pavona gigantea, Pavona clavus and Porites lobata) in an upwelling area in Costa Rica. We examined whether nursery type influenced Pocillopora spp. survival and growth, and how environmental conditions shaped restoration. We monitored the survival and growth of Pocillopora spp. fragments (n = 334) and microfragments of massive species (P. gigantea [n = 148], P. clavus [n = 37], P. lobata [n = 66]) over 11 months. Survival at the end of the gardening period was 51% for Pocillopora spp., 59% for P. clavus, 55% for P. gigantea, and 17% for P. lobata, with a decline after a cease in maintenance caused by the COVID-19 lockdown. Pocillopora spp. fragments in the floating nurseries exhibited higher growth (7.52 ± 1.98 and 6.64 ± 2.91 cm yr-1) than in the A-frame (4.16 ± 2.35 cm yr-1), which suggests the benefits of suspending fragments. For massive microfragments coral growth was 1.92-4.66 cm² yr-1 and were affected by pigmentation loss, causing partial tissue loss and mortality. Our results point towards acclimation to local conditions, and show the need to develop site-specific cost-efficient gardening techniques for massive species, allowing for a multi-species approach to ensure long-term ecosystem recovery. [ABSTRACT FROM AUTHOR]

Purse‐seine tropical tuna fishing in the eastern tropical Pacific Ocean (EPO) results in the bycatch of several sensitive species groups, including elasmobranchs. Effective ecosystem management balances conservation and resource use and requires considering trade‐offs and synergies. Seasonal and adaptive spatial measures can reduce fisheries impacts on nontarget species while maintaining or increasing target catches. Identifying persistently high‐risk areas in the open ocean, where dynamic environmental conditions drive changes in species' distributions, is essential for exploring the impact of fisheries closures. We used fisheries observer data collected from 1995 to 2021 to explore the spatiotemporal persistence of areas of high bycatch risk for 2 species of oceanic sharks, silky shark (Carcharhinus falciformis) and oceanic whitetip shark (Carcharhinus longimanus), and of low tuna catch rates. We analyzed data collected by fisheries scientific observers onboard approximately 200 large purse‐seine vessels operating in the EPO under 10 different flags. Fishing effort, catch, and bycatch data were aggregated spatially and temporally at 1° × 1° cells and monthly, respectively. When areas of high fishing inefficiency were closed the entire study period and effort was reallocated proportionally to reflect historical effort patterns, yearly tuna catch appeared to increase by 1–11%, whereas bycatch of silky and oceanic whitetip sharks decreased by 10–19% and 9%, respectively. Prior to fishing effort redistribution, bycatch reductions accrued to 21–41% and 14% for silky and oceanic whitetip sharks, respectively. Our results are consistent with previous findings and demonstrate the high potential for reducing elasmobranch bycatch in the EPO without compromising catch rates of target tuna species. They also highlight the need to consider new dynamic and adaptive management measures to more efficiently fulfill conservation and sustainability objectives for exploited resources in the EPO. [ABSTRACT FROM AUTHOR]

Coral reef degradation is a worldwide and growing phenomenon triggering habitat transformation from live to dead coral fragments. Macroinvertebrates play key functions in coral reefs, yet research on the size distribution of their community attributes is limited, particularly in the Eastern Tropical Pacific (ETP). We assessed the size distribution of the macroinvertebrate communities in live and dead corals in an ETP coral reef off Colombia. Live coral supported greater macroinvertebrate biomass than dead corals. In live coral, > 90% of total biomass was allocated in the > 8 mm class, which was mostly represented by trapeziid crabs and alpheid shrimps, both obligate symbionts of Pocillopora colonies. No differences were found in macroinvertebrate densities between substrates. Macroinvertebrate communities were dominated by crustaceans, though not in every size class. In live coral, Decapoda dominated in all size classes except 0.5–1 mm, which was the only class where dominance of a single taxon was not observed. In dead corals, the dominance of crustaceans was only observed in the 0.5–1 mm class due to high abundances of tanaidaceans. The remaining size classes were dominated by Polychaeta (1–2 mm, 2–4 mm) and Ophiuroidea (4–8 mm, > 8 mm). Our findings highlight that coral degradation events could lead to macroinvertebrate assemblages with lower biomass contributions, higher proportions of small crustaceans (< 1 mm), and taxonomic shifts. Such transitions from live to dead corals could likely impact food-web interactions between macroinvertebrates and higher trophic levels, potentially altering the ecosystem services offered by coral reefs. [ABSTRACT FROM AUTHOR]

Sightings of pinnipeds in Colombian waters of the Pacific Ocean have sporadically been reported since 1970. Despite the Colombian Pacific region (CPR) not being within their typical distribution range, six pinniped species—the Galápagos fur seal (Arctocephalus galapagoensis), the Galápagos sea lion (Zalophus wollebaeki), the South American fur seal (Arctocephalus australis), the South American sea lion (Otaria byronia), the Juan Fernández fur seal (Arctocephalus philippii), and the southern elephant seal (Mirounga leonina)—have been recorded in recent times. This study presents an overall systematic review of pinniped sightings and strandings from 1970 to 2023 along the Pacific coast of Colombia, with a total of 68 sightings of 80 individuals. Pinnipeds were recorded most often in 1998 (13 individuals), followed by 2014 (nine individuals); 1997 (eight individuals); 1983 (seven individuals); and 1993, 1996, 2015, and 2020 (with three individuals each year). Most pinniped observations correspond to vagrants—solitary, young individuals sighted on the southern coast of the Colombian Pacific, specifically in Tumaco. Some records of these species appear to be influenced by upwelling events and changes in climatic-oceanographic phenomena (ENSO episodes) in the region. Further monitoring is necessary to determine whether species presence and abundance in the CPR is a response to (1) vagrant behavior of the species, (2) altered habitat use associated with bioecological changes in the species populations, and/or (3) shifts in distribution ranges related to potential new habitat suitability. [ABSTRACT FROM AUTHOR]

Antipathes galapagensis is a prevalent habitat-forming black coral in subtidal ecosystems of the Galápagos Marine Reserve (GMR). Despite their ecological importance and status as a CITES-regulated order, little is known about their depth distribution, population structure and ecology in the GMR. Surveys were conducted in 2021 and 2022 at 9 sites in the central Galápagos Archipelago to investigate how black coral densities, occupancy, size, habitat utilization, and epizoan overgrowth varied between 2.0 and 20.0 m depth. The shallowest black corals occurred at 3.4 m depth, one of the shallowest occurrences of an Antipathes spp. in the world. Coral density increased with depth, with a maximum density of 5.2 colonies per m2 observed across the depth range surveyed. Occupancy modeling also yielded curves with increasing probabilities of black coral presence with depth at all sites. Colony height increased with depth at 8 out of 9 sites and was positively correlated with coral density at 6 of 9 sites. Overall, 47% of colonies surveyed occupied cryptic habitats and 53% were attached to exposed substrate, but black coral habitat usage patterns varied with depth at 5 of 9 sites. At these sites, colonies on shallower transects (5.0, 10.0 m depth) more frequently displayed cryptic habitat usage while colonies along the deeper transects (15.0, 20.0 m) were more often exposed. In general, coral density, probability of occupancy, height, and exposed habitat utilization increased with depth, while the average degree of overgrowth and number of epibiont taxa were unrelated to depth. Five hypotheses regarding factors potentially limiting the shallow (upper) depth distribution of A. galapagensis—ranging from negative impacts of the physical environment to high predation on exposed substrates—are presented for future testing. These results provide a comprehensive ecological characterization of Galápagos black coral populations that can be used to assess the impact of future environmental change and applied to management decisions for this key marine foundation species in the GMR. [ABSTRACT FROM AUTHOR]

El Niño–Southern Oscillation (ENSO) phases and flavors, as well as off-equatorial climate modes, strongly influence sea surface temperature (SST) patterns in the eastern tropical Pacific and downstream climate. Prior studies rely on EOFs (which characterize fractional SST variance) to diagnose climate-scale SST structures, limiting the ability to link individual ENSO flavors with downstream phenomena. Hierarchical and k-means clustering methods are used to construct Eastern Pacific patterns from the ERSST dataset spanning 1950 to 2021. Cluster analysis allows for the direct linkage of individual SST years/seasons to ENSO phase, providing insight into ENSO flavors and associated downstream impacts. In this study, four clusters are revealed, each depicting unique SST patterns influenced by ENSO and Pacific Meridional Mode (PMM) phases. A case study demonstrating the utility of the clusters was also carried out using accumulated cyclone energy (ACE) in the Atlantic and Eastern Pacific basins. Results showed that Eastern Pacific (EP) El Niño suppresses Atlantic tropical cyclone (TC) activity, while Central Pacific (CP) La Niña enhances it. Further, EP El Niño, coupled with positive PMM, amplifies ACE. Ultimately, the methods used herein offer a cleaner analysis tool for identifying dominant SSTA patterns and employing those patterns to diagnose downstream climatic effects. [ABSTRACT FROM AUTHOR]

The decline of coral reefs has increased interest in ecological restoration. Due to the scarcity of coral gardening projects in the Eastern Tropical Pacific, improving our understanding of such techniques is key. We report the results of coral gardening using the branching Pocillopora spp. and massive coral species (Pavona gigantea, Pavona clavus and Porites lobata) in an upwelling area in Costa Rica. We examined whether nursery type influenced Pocillopora spp. survival and growth, and how environmental conditions shaped restoration. We monitored the survival and growth of Pocillopora spp. fragments (n = 334) and microfragments of massive species (P. gigantea [n = 148], P. clavus [n = 37], P. lobata [n = 66]) over 11 months. Survival at the end of the gardening period was 51% for Pocillopora spp., 59% for P. clavus, 55% for P. gigantea, and 17% for P. lobata, with a decline after a cease in maintenance caused by the COVID-19 lockdown. Pocillopora spp. fragments in the floating nurseries exhibited higher growth (7.52 ± 1.98 and 6.64 ± 2.91 cm yr-1) than in the A-frame (4.16 ± 2.35 cm yr-1), which suggests the benefits of suspending fragments. For massive microfragments coral growth was 1.92-4.66 cm2 yr-1 and were affected by pigmentation loss, causing partial tissue loss and mortality. Our results point towards acclimation to local conditions, and show the need to develop site-specific cost-efficient gardening techniques for massive species, allowing for a multi-species approach to ensure long-term ecosystem recovery.

The scalloped hammerhead shark (Sphyrna lewini) is one of the most iconic marine species across the Eastern Tropical Pacific (ETP), yet little is still known about its reproductive biology and the origin of their nursery areas, despite a continuous global decline in their populations. Understanding the origin of shark nurseries is a complex task; however, it is known that the obtention of resources in the first stages of life of placental sharks occurs through maternal reminiscence, thus it is possible to infer the origin of the energy that neonates accumulate during their gestation. In this study we assessed the ecological connectivity and nursery ground use by undertaking a stable isotope analysis of carbon (δ13C) and nitrogen (δ15N) in skin samples of neonates S. lewini across much of their distribution in the ETP, including the Galapagos Marine Reserve (GMR). Our isotopic mixing models revealed that the S. lewini neonates found in the GMR, have isotopic information similar to adult females inhabit in the Galapagos archipelago, suggesting that they are direct descendants of the females that inhabit the GMR. While neonates found off the continental coasts of Ecuador and Panama have isotopic signatures like those of adult females inhabiting several locations across the ETP. This work provides insight into the origin of nursery areas used by adult S. lewini that aggregate in large numbers across oceanic islands of the ETP, highlighting the value of isotopic models to generate useful information for the conservation of sharks. [ABSTRACT FROM AUTHOR]

Tropical pelagic predators are exploited by fisheries and their movements are influenced by factors including prey availability, temperature, and dissolved oxygen levels. As the biophysical parameters vary greatly within the range of circumtropical species, local studies are needed to define those species' habitat preference and model possible behavioral responses under different climate change scenarios. Here, we tagged yellowfin tuna Thunnus albacares in the Galápagos Marine Reserve and tracked the horizontal and vertical movements of eight individuals for 4–97 days. The tuna traveled a mean of 13.6 km day−1 horizontally and dispersed throughout the archipelago and in offshore waters inside the Galápagos Marine Reserve and in the surrounding Ecuadorian exclusive economic zone. Vertically, they traveled a mean of 2 km day−1, although high‐resolution data from a recovered tag suggested that transmitted data underestimated their vertical movement by a factor of 5.5. The tracked yellowfin tuna spent most of their time near the surface, with an overall mean swimming depth of 24.3 ± 46.6 m, and stayed shallower at night (11.1 ± 16.3 m) than during the day (37.7 ± 60.9 m), but on occasion dived to cold, oxygen‐poor waters below 200 m. Deep dives were commonly made during the day with a mean recovery period of 51 min between exposures to modeled oxygen‐limiting conditions <1.5 mL L−1, presumably to re‐oxygenate. The depth and frequency of dives were likely limited by dissolved oxygen levels, as oxygen‐depleted conditions reach shallow depths in this region. The main habitat of tracked yellowfin tunas was in the shallow mixed layer, which may leave them vulnerable to fishing. Vertical expansion of low‐oxygen waters under future climate change scenarios may further compress their habitat, increasing their vulnerability to surface fishing gear. [ABSTRACT FROM AUTHOR]

Sea turtle nesting activity on newly monitored beaches yield important data to support future regional and global conservation assessments. Here, we report on nesting activity of Olive Ridley (Lepidochelys olivacea) at Cascajilloso beach in Pacific Panama based on data from a new hatchery during seasons 2019, 2020 and 2021. Further to this, we conducted a field experiment analyzing the effects of artificial shade versus unshaded treatments on hatchlings' biometric characteristics, hatching success, incubation success and the incubation period. The analyses of three seasons showed that nesting activity, based on number of egg clutches transferred to the hatchery, reached a peak between September (33%) and October (25%). Curved carapace length (CCL) of nesting females (64.3–66.2 cm) was similar to other populations of the Eastern Tropical Pacific (ETP). The number of eggs clutches were 80 in 2019, 73 in 2020 and 108 in 2021; however, the clutch size was slightly smaller (93.92 ± 18.78 eggs) compared with other populations of the ETP. This could be a phenotypic variation of nesting females at this beach. The ability to move egg clutches to the hatchery was affected during 2020 season due to COVID19 restrictions. Heavy rainfall during the incubation period caused a reduction in ambient temperature resulting in cooler (maximum average 29.9°C) nest temperatures registered under artificial shade and unshaded treatments. This could result in males hatchlings during the 2020 season. The warmer temperatures in our experimental nests produced heavier hatchlings contrary to general assumptions, but this was also related to straight carapace length only after a threshold value of 40 mm. Hatchlings under the artificial shade were able to grow to a certain size but potentially at the costs of storing less mass (trade‐off). Ongoing beach patrolling and hatchery management techniques with long‐term baseline data collection are needed to secure the nesting population of L. olivacea in this recently surveyed beach. [ABSTRACT FROM AUTHOR]

Introduction: Killer whales (Orcinus orca) have a global distribution, but many low-latitude populations such as the Eastern Tropical Pacific are not well studied. Objective: Provide a review of killer whale sightings in the Exclusive Economic Zone of the Pacific of Guatemala, for which there has previously been little information. Methods: We reviewed national and regional publications, as well as anecdotal records of killer whale sightings in Guatemala. Results: We document five sightings spanning three decades (1990-2020). Four sightings were recorded between 2010 and 2020 and occurred within the San José Canyon or over the continental shelf. Group size varied from 1-15 individuals (: 6 ± 4.3). We report a photographic match of three killer whale individuals from a single pod previously sighted in Cabo Corrientes, México, 11 years and 1 778 km apart. We also describe an interaction between a killer whale pod and two adult Bryde's whales (Balaenoptera edeni), in which the Bryde's whales followed a female killer whale and its calf. Conclusions: This study represents a contribution to the knowledge of killer whales in the region. It highlights the importance of data collection from both scientific and anecdotal records and supports the need of establishing national and regional monitoring and conservation programs for cetaceans. [ABSTRACT FROM AUTHOR]

Introduction: Even though they occur worldwide in tropical and subtropical waters, Bryde's whales (Balaenoptera edeni) are one of the most enigmatic of all the balaenopterid species. Previous research has reported the presence of Bryde's whales off the Pacific coast of Panama, but little is known about their behaviors, abundance, and distribution in these waters. Objective: We report on an area in the Gulf of Chiriqui, Panama, where Bryde's whales have regularly been sighted. Methods: We conducted small-boat surveys for marine mammals in the Gulf of Chiriqui between 2001 and 2022, during both the austral (26 300 km) and boreal (4 700 km) winter seasons. Results: We made 25 sightings of 33 Bryde's whales. Sightings were made in nine of the years surveyed, and most were in the austral winter season (92 %). Most sightings were of one animal (80 %), and one sighting was of a mother-calf-escort trio. The aggregation area appears near the Contreras Islands, where most sightings (84 %) were made. We have photo-identified 14 individual whales using the dorsal fin. One individual has been sighted over two years (2014 and 2015), while the remaining have been documented only once. No photographic matches have been made to other areas. Conclusions: The persistent use of this aggregation area could indicate it is used for foraging, and the presence of a calf may indicate the area is also used for reproduction. The one inter-annual resight suggests this area may be used repeatedly by some of the same animals. Further research is needed off Panama to better understand this population of Bryde's whales, its conservation status, and its relationship to the broader eastern tropical Pacific populations. Expanding the marine protected areas in the Gulf of Chiriqui may be warranted in order to protect this aggregation area. [ABSTRACT FROM AUTHOR]

Herein we provide the first published records for Azurina intercrusma and a correction of previous Scuticaria tigrina records within the Galápagos Marine Reserve. The former had not previously been reported north of the southern Ecuadorian coastline and represents a significant step outside of its known distribution for this cold-water species. Scuticaria tigrina had been mentioned in previous literature as present, but its inclusion appears to have been in error; we confirm its presence as a vagrant and provide evidence of live observations in different parts of the archipelago.

El Niño–Southern Oscillation (ENSO) phases and flavors, as well as off-equatorial climate modes, strongly influence sea surface temperature (SST) patterns in the eastern tropical Pacific and downstream climate. Prior studies rely on EOFs (which characterize fractional SST variance) to diagnose climate-scale SST structures, limiting the ability to link individual ENSO flavors with downstream phenomena. Hierarchical and k-means clustering methods are used to construct Eastern Pacific patterns from the ERSST dataset spanning 1950 to 2021. Cluster analysis allows for the direct linkage of individual SST years/seasons to ENSO phase, providing insight into ENSO flavors and associated downstream impacts. In this study, four clusters are revealed, each depicting unique SST patterns influenced by ENSO and Pacific Meridional Mode (PMM) phases. A case study demonstrating the utility of the clusters was also carried out using accumulated cyclone energy (ACE) in the Atlantic and Eastern Pacific basins. Results showed that Eastern Pacific (EP) El Niño suppresses Atlantic tropical cyclone (TC) activity, while Central Pacific (CP) La Niña enhances it. Further, EP El Niño, coupled with positive PMM, amplifies ACE. Ultimately, the methods used herein offer a cleaner analysis tool for identifying dominant SSTA patterns and employing those patterns to diagnose downstream climatic effects.

The scalloped hammerhead shark (Sphyrna lewini) is one of the most iconic marine species across the Eastern Tropical Pacific (ETP), yet little is still known about its reproductive biology and the origin of their nursery areas, despite a continuous global decline in their populations. Understanding the origin of shark nurseries is a complex task; however, it is known that the obtention of resources in the first stages of life of placental sharks occurs through maternal reminiscence, thus it is possible to infer the origin of the energy that neonates accumulate during their gestation. In this study we assessed the ecological connectivity and nursery ground use by undertaking a stable isotope analysis of carbon (δ13C) and nitrogen (δ15N) in skin samples of neonates S. lewini across much of their distribution in the ETP, including the Galapagos Marine Reserve (GMR). Our isotopic mixing models revealed that the S. lewini neonates found in the GMR, have isotopic information similar to adult females inhabit in the Galapagos archipelago, suggesting that they are direct descendants of the females that inhabit the GMR. While neonates found off the continental coasts of Ecuador and Panama have isotopic signatures like those of adult females inhabiting several locations across the ETP. This work provides insight into the origin of nursery areas used by adult S. lewini that aggregate in large numbers across oceanic islands of the ETP, highlighting the value of isotopic models to generate useful information for the conservation of sharks.

Coiba National Park (PNC) is one of the most important marine protected areas in the Americas, as an essential part of the Eastern Tropical Pacific Marine Corridor. As a marine protected area, its main objective is biodiversity conservation, although nature-based tourism and nautical activities are allowed. This research focused on the application of the Coastal Scenery Evaluation System (CSES) method along the entire PNC coastline. Based on two field visits, covering more than 200 km of coastline, 42 beaches were identified and evaluated, the vast majority in highly natural conditions. Similarly, five beaches were analyzed for biological data associated with the diversity of coastal fauna, as a preliminary inventory. The result of the CSES fuzzy logic calculation classified 64% of the beaches in the two highest scenery grades, with only 3 beaches in class IV, and none in class V. Regarding the biological data, macroinvertebrates were mostly represented by 13 mollusks, 1 echinoderm and 1 crustacean. In addition to scientific results, the research identified those beaches with the potential to be certified as coastal scenery of heritage value. In conclusion, this evaluation will help guide nature-based tourism actions within the PNC, and will serve as a baseline for future monitoring of the impact that tourism activity may have on beach fauna and natural attributes.

Habitat heterogeneity is one of the main factors influencing the dynamics in benthic marine communities. This work assessed the influence of different degrees of coral development − i.e., coral patches and coral communities − on the spatial patterns of echinoderm assemblage in the central Mexican Pacific. The fieldwork was conducted in September 2019 at six sites with different coral reef development. The composition and abundance of echinoderm species and the coverage of corals and other benthic components (substrate characteristics) were quantified at each site. Different community attributes (species richness and Shannon diversity), species similarity patterns, and their relationships with the benthic habitat structure were also surveyed. The results suggested that the echinoderm assemblage of the southern coast of Jalisco includes species that are representative in comparable ecosystems of the eastern tropical Pacific, highlighting the sea urchin Diadema mexicanum and the sea cucumber Pseudocnus californicus as the most abundant species. The echinoderm assemblage structure evidenced dissimilarities among sampling sites and between site conditions (coral patches vs. coral communities), caused mainly by the different abundance of the sea urchin P. californicus, and the sea urchins D. mexicanum, Toxopneustes roseus, Eucidaris thouarsii, and Echinometra vanbrunti. The coral Pocillopora was associated with coral patches, while the massive coral Porites was mainly related to coral communities. These coral species and articulated calcareous algae were the most relevant environmental variables explaining the spatial variation in the echinoderm assemblage. The highest richness, abundance, and diversity of echinoderms were found in coral community habitats. This study indicates that different degrees of coral development, such as coral patches and coral communities, influence the spatial patterns of echinoderm assemblage. [ABSTRACT FROM AUTHOR]

Herein we provide the first published records for Azurina intercrusma and a correction of previous Scuticaria tigrina records within the Galápagos Marine Reserve. The former had not previously been reported north of the southern Ecuadorian coastline and represents a significant step outside of its known distribution for this cold-water species. Scuticaria tigrina had been mentioned in previous literature as present, but its inclusion appears to have been in error; we confirm its presence as a vagrant and provide evidence of live observations in different parts of the archipelago. [ABSTRACT FROM AUTHOR]

The giant mottled eel (Anguilla marmorata) is distributed mostly in the Indo‐West Pacific. However, a few records indicate the presence of this eel in the Tropical Central and East Pacific. In April 2019, an eel specimen was caught in a small stream in San Cristobal Island, Galápagos. Morphological and molecular characters (16S and Cytb mtDNA sequences) confirmed the species as A. marmorata Quoy & Gaimard, 1824. The re‐discovery of A. marmorata in Galápagos supports the hypothesis of an eastward range expansion from the west, probably through the North Equatorial Counter‐Current. [ABSTRACT FROM AUTHOR]

Feeding habits and habitat use inform ecosystem-based management strategies for commercial fish species. A consumer's diet can be assessed through stomach content analysis (SCA), bulk stable isotope analysis (BSIA) and compound-specific stable isotope analysis of amino acids (CSIA-AA). Our research establishes the first approach combining these traditional and novel techniques to provide insight on the movements and trophic ecology of dolphinfish (Coryphaena hippurus) in the Mexican Central Pacific (MCP) during 2013. Dolphinfish SCA (n = 311), muscle δ15N and δ13C BSIA (n = 148), and δ15N CSIA-AA (n = 9) were performed to assess trophic and movement patterns. Diet was composed of 59 prey items. According to the Prey-Specific Index of Relative Importance, the main prey were Argonauta spp. (24%), Portunus xantusii (11%), Dosidicus gigas (7%), and Selar crumenophthalmus (7%). Diet differed between seasons and age class but not by sex. Trophic position did not change with body size based on SCA or SIA with average estimates of 3.5, 4.1, and 4.3 based on BSIA, CSIA, and SCA, respectively. Adult dolphinfish showed a shift in their isotopic niche; bulk δ15N values varied widely in adults (⁓ 10‰) suggesting movements through different isoscapes while juveniles had more constrained values consistent with residency within the regional isoscapes. These results were supported by differences in source amino acid δ15N mean values between juveniles (4.6‰) and adults (0.8‰). Our findings suggest that the MCP is a migration corridor for dolphinfish between foraging areas across the Eastern Tropical Pacific. [ABSTRACT FROM AUTHOR]

Foraging outcomes dictate the nutritional resources available to an organism and may vary with intrinsic factors, like age. Thus, understanding how age affects foraging performance, alone or in interaction with extrinsic factors (like environmental quality), improves our understanding of aging processes in the wild. We examined how foraging traits, measured across five breeding seasons, change with age, environmental variation, and their interaction in Nazca boobies (Sula granti), a pelagic seabird in Galápagos. We evaluated the hypotheses that (1) foraging performance is better in middle‐aged birds than in young ones, and that (2) foraging performance is better in middle‐aged birds than in old ones. Furthermore, favorable environmental conditions will either (3) attenuate age differences in foraging performance (by relieving constraints on young, inexperienced and old, senescent age classes), or (4) accentuate age differences (if middle‐aged birds can exploit abundant resources better than other age classes can). Incubating birds tagged with GPS loggers (N = 815) provided data on foraging performance (e.g., total distance traveled, mass gained) to evaluate interactions between age and environmental variation (e.g., sea surface temperature). Poor environmental conditions associated with the cool phase of the El Niño‐Southern Oscillation increased foraging effort, including foraging distance and duration, for example. Across age classes, foraging boobies responded similarly to environmental variation except for female mass gain rate: age‐related declines in mass gain rate were reduced under favorable environmental conditions. Birds of different ages also searched in somewhat distinct areas in the poor conditions of 2016, but not in other years. In several foraging traits, including foraging duration and distance, female boobies showed predicted early‐life improvement and late‐life decline, following the established pattern for reproductive traits in this species. Thus, deficits in resource acquisition (this study) may contribute to the poor survival and reproductive outcomes previously observed in old Nazca boobies, particularly in females. [ABSTRACT FROM AUTHOR]

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Due to the increasing challenge of meeting human demands for metals from land-based resources, interest in extracting mineral ores from the deep sea has gained momentum in recent years. Targeted mining of deep-seabed minerals could have adverse effects on the associated ecosystems, but knowledge on the biological communities found there, their structure and functions is still limited. The focus of this study is to provide an overview on isopod crustaceans from the Clarion Clipperton Fracture Zone (CCFZ), an area well-known for its abundance of high-grade polymetallic nodules. Isopods generally comprise an important part of the macrofaunal communities of soft deep-sea sediments and indeed are one of the most dominant macrobenthic groups in the CCFZ. In this review, we have compiled all available data and information on isopod diversity and distribution in the CCFZ in a hybrid manner, which includes published data from the literature as well as the analysis of previously unpublished sources and newly collected data. Although isopods are one of the more prevalent and better-known groups of the CCFZ fauna, this study shows that it is still remarkably difficult to obtain a clear perception of isopod diversity and distribution, as well as the factors that could be responsible for the observed patterns. In many places, knowledge remains incomplete, which is largely due to the low sampling and taxonomic effort, non-standardised sample protocols and the limited taxonomic inter-calibration between studies. The latter is pivotal due to the high proportion of undescribed and presumably new species that typically occur there. An important starting point would therefore be to increase sampling effort and its spatial and temporal coverage in a standardised way, to intensify (integrative) taxonomic work as well as to facilitate sample and data exchange between scientists and contractors. These are fundamental requirements to improve our understanding of the biodiversity of isopods, but also of other faunal groups, in the CCFZ, before mining operations begin. [ABSTRACT FROM AUTHOR]

The olive ridley sea turtle is predominantly an epipelagic species with no apparent migration corridors. Research in feeding areas in other sea turtle species has identified aggregations of individuals from diverse backgrounds; however, no specific feeding areas have been identified for the olive ridley. We used mtDNA control region sequencing to identify the haplotype composition of 85 olive ridley turtles (adult and immature turtles from both sexes) captured and released in Central Mexican Pacific waters. Amplified fragments of the control region (751 bp) revealed the presence of 17 haplotypes (h = 0.5877 ± 0.0622 and π = 0.001698 ± 0.001185), and 16 of them were phylogenetically grouped within the lineage of the Eastern Pacific, but the haplotype Lo37 showed close evolutionary relationships with the lineage of the East Coast of India. Lagrangian drifter data showed that West–East transport from the Indo-Pacific to the tropical Eastern Pacific might be possible through passive drift. These results highlight the importance of more genetic studies offshore and the role of the ocean currents in the migratory behavior of olive ridleys, as well as the need to establish multinational strategies for the conservation and management of the species in international waters. [ABSTRACT FROM AUTHOR]

Located in the eastern tropical Pacific, the Galápagos Islands are an oceanic insular ecosystem subject to strong environmental variability driven by local and regional processes. Past research has shown that such conditions can attract and sustain at least 23 cetacean species, out of which 14 are common, including nine Delphinids, one Ziphiid, one Physeterid, and three Balaenopterids. These species occupy both coastal and oceanic habitats, most are present year-round, and a few are migratory. However, research on cetaceans in Galápagos has been sporadic and chronically underfunded and is not currently considered a priority in the research agenda for Galápagos. Based on a review of existing information and an assessment of knowledge gaps, here we identify priorities for ecological research on cetaceans in Galápagos along five topical areas: 1) spatiotemporal occurrence, 2) population assessment, 3) health assessment, 4) social ecology, and 5) trophic ecology. Addressing these knowledge gaps will also help inform actions to preserve cetacean biodiversity and to manage human activities involving or affecting cetaceans in Galápagos. Given the logistical and funding challenges of conducting cetacean research in Galápagos, we recommend optimizing data sampling and accessibility via integrated research protocols and open data repositories. We also recommend capitalizing on local citizen science activities, such as those conducted from cruise ships and whale-watching tours, which can serve as platforms of opportunity for obtaining basic data, thereby contributing to long-term data acquisition. Our proposed priorities should be assessed by Ecuadorian and Galápagos governmental institutions in broad and inclusive consultation with stakeholders and the scientific community prior to development and implementation of a research agenda. Collectively, these efforts will advance our understanding of the ecological role that marine megafauna, such as cetaceans, play in Galápagos and other oceanic islands, including maintaining large-scale connectivity and mitigating climate change.

Introduction: Environmental and intrinsic factors such as seawater temperature, salinity, nutrient concentration, upwelling, species, and life history can influence coral outplant survival and growth, and in consequence, the effectiveness of restoration. Thus, it is key to understand how these factors can shape coral outplant performance to ensure the long-term success of a restoration program. Objective: To establish the survival and growth rate of outplanted coral nursery-reared colonies of branching Pocillopora spp. and massive corals Pavona gigantea, Pavona clavus, and Porites lobata in Bahía Culebra, North Pacific of Costa Rica, and to determine whether the site of origin of the coral fragment and the presence of seasonal upwelling affected the growth of Pocillopora outplants. Methods: From September 2020 to September 2021, we monitored the survival, health, and growth of 30 Pocillopora spp. colonies from six donor sites, and 31 fragments of massive species (P. gigantea [n = 18], P. clavus [n = 8], P. lobata [n = 5]) that were outplanted to a degraded reef. We recorded in situ seawater temperature, salinity, and nutrient concentration. Results: By the end of the year, 100 % of the Pocillopora spp. outplants survived. Survival was 71.4 % for P. clavus, 47.5 % for P. gigantea, and 20 % for P. lobata. Coral tissue loss and predation marks were observed at least once in 71 % of massive outplants. Pocillopora spp. colonies increased their initial area in 333.1 %, at a rate of 9.98 ± 1.69 cm yr-1. The site of origin of the outplant influenced growth rate, but not the presence of seasonal upwelling. Massive species fragments grew at a rate of 1.35 ± 0.24 cm yr-1 for P. clavus, 1.48 ± 0.21 cm yr-1 for P. gigantea, and 0.61 cm yr-1 for P. lobata, with no differences among them. Conclusions: Environmental conditions at site level allow for high survival and growth of Pocillopora spp. outplants, previously considered as sensitive to stressors, and point towards acclimation to seasonal upwelling. Although survival of massive species was lower, developing a multi-species approach is key to enhance restoration success. [ABSTRACT FROM AUTHOR]

Introduction: Coral-reef communities are considered one of the most biodiverse, but also most threatened, marine ecosystems, and the accelerating loss of habitat over the past decades warrants active intervention. Objective: The present study demonstrates the successful implementation of a low-impact restoration technique in three Central Mexican Pacific degraded coral communities, using a protocol based on natural fragmentation ("fragments of opportunity") of the branching coral Pocillopora spp., considered the most abundant and primary carbonate-producing coral species of the Eastern Tropical Pacific. Methods: The restoration program was implemented in two offshore and one inshore coraline areas. The relationships between seawater temperature and coral survival, growth, and attachment rate were assessed over one year, with 183 fragments monitored each month. Results: The mean coral growth rate was 3.3 ± 0.1 mm mo-1, with annual growth rates in length and width of 39.9 ± 14.2 and 36.5 ± 19.5 mm yr-1, respectively. Self-attachment efficiency was 78 % and the survival rate was high (84 %). The growth rate differed significantly among reefs. Conclusions: Upon monitoring directly fragmented corals over a year, growth rates were deemed high enough to merit active restoration in the region. However, our data show that structural and abiotic differences and seasonal variability must be considered overall in successful long-term coral community restoration initiatives in the eastern Pacific region. [ABSTRACT FROM AUTHOR]

Introduction: Hermatypic corals have the capacity to construct the physical reef-framework and maintain the balance of coral reef functionality. However, in the past three decades, coral communities have been menaced by natural and anthropic pressures, resulting in an abrupt coral cover decline, and slow natural recovery. To mitigate coral reef collapse, assisted restoration techniques has been implemented and improved worldwide, However, the long-term effects of such interventions on ecological attributes have been scarcely reported. Objective: This study evaluated the effect of assisted coral intervention on calcium carbonate production (kg CaCO3 m-2 yr-1) and ecological volume (cm3) yielded by branching and massive corals from the central Mexican Pacific. Methods: We used colony size, extension rate, and skeletal density measurements of direct outplanted Pocillopora and Pavona coral species to calculate coral carbonate production, ecological volume, and model their long-term potential. Results: Coral carbonate produced after one-year of outplanting increased by 42 % (1.17 kg CaCO3 m-2 yr-1), where Pocillopora spp. and Pavona clavus corals contribute with 0.97 and 0.20 kg CaCO3 m-2 yr-1, respectively. The ecological volume also increased by 384 cm3 for Pocillopora and 56 cm3 for Pavona after one year period. Furthermore, the results suggest that long-term coral restoration actions (10 years) have the potential to significantly increase carbonate production. Conclusions: our data indicate that coral restoration initiatives have the potential to help mitigate the current low calcium carbonate production of Mexican Pacific reefs and may significantly contribute to the long-term maintenance of reef-framework based on ecological engineering tools, such initiatives represent essential functional properties related to reef ecosystem services provision. [ABSTRACT FROM AUTHOR]

Introduction: Black coral studies in Central America are scarce. Even though Antipathes has been reported as one of the coral genera that has succumbed to anthropic pressure, publications haven't been made on El Salvador black coral species, habitats, distribution, and importance. Objective: To identify the species of black corals in Los Cóbanos, El Salvador, and qualitatively characterize the abundance and size of the colonies; and to identify the most conspicuous epibiont species in the colonies. Methods: Visual census with SCUBA diving for qualitative characterization and underwater photographs were taken for the registration of epibiont species in six points of Los Cóbanos, between December 2021 to February 2022 and six to characterize size of the colonies and abundance. Results: The first report of black coral forests in El Salvador was made, constructed by two species: Myriopathes panamensis and Antipathes galapagensis. We also reported, for first time, the occurrence of M. panamensis, Pacifigorgia senta, Heterogorgia verrucosa, Eugorgia mutabilis, Nemathus californicus and Amphiodia sp. We found disturbances of anthropic origin, such as marine debris and damage to the colonies by anchors. Conclusions: It is necessary to establish efforts towards the knowledge of the fauna of mesophotic zones, mainly in vulnerable marine ecosystems of black coral forests and gorgonian gardens. There is an important potential, and data will help overcome information gaps in the region, allowing for better conservation measures. [ABSTRACT FROM AUTHOR]

Kelps are among the most studied groups of macroalgae globally, as they are large foundation species that form some of the world's most productive and diverse marine habitats. Yet little is known about diversity and ecology of tropical kelps, which tend to inhabit the more difficult to survey mesophotic zone. Eisenia galapagensis is the first tropical kelp species to be recorded globally, and is an endemic and endangered species to the Galapagos. Here, we reveal the presence of previously unknown off-shore mesophotic kelp populations in the Galapagos, made up by a potentially new Eisenia species for the region, and present phylogenetics and morphological analysis to support our claim. We find that these novel populations form extensive kelp forest habitats with a kelp density of 2.6 ± 1.5 m−2 at depths of 48–67 m, where mean water temperatures are 3–5 ℃ cooler than at the surface (18.1–19.9 ℃). Despite low levels of light and macronutrients (measured in August 2019), observations of juveniles and sori on blades suggests these kelp populations are successfully reproducing and recruiting. Our findings provide information about foundation species and complex marine communities previously unknown to managers of the Galápagos Marine Reserve. They also support the notion that this region is uniquely important for harboring brown macroalgal diversity. Our study highlights critical knowledge gaps on the distribution of primary foundation species in colder mesophotic zones, and how their invisibility from the surface prevents their inclusion in current conservation strategies. [ABSTRACT FROM AUTHOR]

The organisms that inhabit Oxygen Minimum Zones (OMZ) have specialized adaptations that allow them to survive within a very narrow range of environmental conditions. Consequently, even small environmental perturbations can result in local species distribution shifts that alter ecosystem trophodynamics. Here, we examined the effect of changing sea water temperatures and oxygen levels on the physiological performance and metabolic traits of the species forming marine demersal communities along the OMZ margins in the Costa Rican Pacific. The strong temperature and oxygen gradients along this OMZ margin provide a "natural experiment" to explore the effects of warming and hypoxia on marine demersal communities. We identified two distinct marine fauna communities separated by an environmental oxygen partial pressure threshold of 0.003–0.009 atm. The community inhabiting cooler waters with less oxygen was comprised of species with very low oxygen demands, while the second community inhabiting warmer waters with more oxygen was comprised by a higher diversity of species with higher oxygen demands. We also compared the community composition across different El Niño Southern Oscillation phases. During "neutral" and El Niño conditions, with relatively warmer temperatures and higher oxygen levels, species' average oxygen demand was higher, and species stayed at greater depths than during the cooler, low oxygen, La Niña phases. Our findings suggest that the effects of environmental temperature and oxygen levels on the structure of demersal communities within OMZs can be predicted by understanding species' oxygen demand. This study highlights the vulnerability of demersal ecosystem structures surrounding the Costa Rican OMZ to deoxygenation and warming under climate change. [ABSTRACT FROM AUTHOR]

A sediment trap had been deployed at 1250 m depth in the Eastern Tropical Pacific (ETP) from September 2009 to July 2010, with the aim of understanding the temporal and vertical variability of particle flux. During the monitoring period, total particle flux varied from 12.4 to 101.0 mg m-2day-1, with the higher fluxes in January-March 2010. Biogenic particle flux varied in phase with the total particle flux. The increase in total particle flux during January-March 2010 was attributed to the enhanced biological production in the surface layer caused by wind-driven mixing in response to the seasonal shifts in the location of the Intertropical convergence zone. The export ratio (e-ratio) was estimated using the particulate organic carbon flux and satellite-derived net primary production data. The estimated e-ratios changed between 0.8% and 2.8% (1.4± 0.6% on average). The ratio recorded in the negative phase of Pacific decadal oscillation (PDO) was similar to the previous results obtained from the ETP during the 1992/93 periods in the positive phase of PDO. This suggests that the regime shift of the PDO is not related to the carbon export ratio. [ABSTRACT FROM AUTHOR]

The Pacific coast of Colombia is characterized by mangrove ecosystems which play a crucial role as possible nurseries for juvenile sharks. However, trophic food webs from coastal ecosystems are heavily disturbed by increased fishing pressure, which affects numerous shark species. In this region of the Eastern Tropical Pacific (ETP), fisheries' data from coastal areas are scarce and unspecific, as most sharks from artisanal fisheries are landed decapitated and finless, making their morphological identification difficult. For the establishment and implementation of effective regional conservation and management policies, information on the diversity and population dynamics of shark species is crucial. We therefore sequenced the mitochondrial NADH2 gene of 696 samples taken from fishermen's landings of shark's bycatch along the Colombian north Pacific coast. We were able to identify 14 species of sharks, two of the most abundant species were Sphyrna lewini and Carcharhinus falciformis, both evaluated on IUCN the Red List of Threatened species (Critically Endangered and Vulnerable) and CITES regulated. We found low genetic diversity in the sampled area increasing the concern for both species in the region, even more considering that the majority of individuals were juveniles. Our results showed the importance of genetic markers for first population genetic insights as a complementary tool during the decision-making process in management plans. For this specific region, strategies such as the delimitation of conservation priority areas or the regulation of fishing gears could help improve the sustainability of shark populations in the Colombian Pacific. [ABSTRACT FROM AUTHOR]

The effective conservation of highly migratory marine species is only possible if core areas of activity and critical habitat can be identified within the vast and dynamic oceanic environment and later on used to delineate marine protected areas (MPAs). However, gathering population-level data and identifying universal patterns within a species or population can be difficult when only a small sample size exists and individuals are not ecologically interchangeable. In addition, the open ocean beyond the Exclusive Economic Zone (EEZ) of a country is considered the high-seas and is not part of any jurisdiction and therefore challenging to govern by laws. Granting protection to species using these waters is sometimes virtually impossible. Another challenge is the dynamic nature of the oceanic environment. MPAs are usually based on spatially explicit and static areas, but migratory routes can shift following available food, currents, and temperatures or else, potentially rendering designated areas useless. The red-listed olive ridley turtle is known for its nomadic migratory and feeding behavior and a divergent nesting strategy among females. Our study used two approaches to identify critical habitats for the population nesting in Costa Rica and feeding in the Eastern Tropical Pacific. One was based on a static Kernel Density Approach to identify core areas. The other was a habitat preference model that took into account changing environmental variables such as sea surface temperature and chlorophyll-a concentrations. We were able to identify core areas at the population level by pooling two datasets and increasing our sample size. Our habitat preference model showed a high correlation of olive ridley presence with all tested environmental variables, except chlorophyll-a concentration. Our results reveal that olive ridleys use mainly regions that fall within EEZs and, therefore, the jurisdiction of six countries in Central America and provide an essential conservation tool.

The Pacific coast of Colombia is characterized by mangrove ecosystems which play a crucial role as possible nurseries for juvenile sharks. However, trophic food webs from coastal ecosystems are heavily disturbed by increased fishing pressure, which affects numerous shark species. In this region of the Eastern Tropical Pacific (ETP), fisheries’ data from coastal areas are scarce and unspecific, as most sharks from artisanal fisheries are landed decapitated and finless, making their morphological identification difficult. For the establishment and implementation of effective regional conservation and management policies, information on the diversity and population dynamics of shark species is crucial. We therefore sequenced the mitochondrial NADH2 gene of 696 samples taken from fishermen’s landings of shark’s bycatch along the Colombian north Pacific coast. We were able to identify 14 species of sharks, two of the most abundant species were Sphyrna lewini and Carcharhinus falciformis, both evaluated on IUCN the Red List of Threatened species (Critically Endangered and Vulnerable) and CITES regulated. We found low genetic diversity in the sampled area increasing the concern for both species in the region, even more considering that the majority of individuals were juveniles. Our results showed the importance of genetic markers for first population genetic insights as a complementary tool during the decision-making process in management plans. For this specific region, strategies such as the delimitation of conservation priority areas or the regulation of fishing gears could help improve the sustainability of shark populations in the Colombian Pacific.

Reef development occurs commonly under oligotrophic conditions that favor corals over competitors. In the Eastern Tropical Pacific (ETP), coral communities develop under highly dynamic environmental conditions that may benefit organisms involved in reef bioerosion. To understand how coral performance and maintenance change with increasing urban pressure in the ETP, we evaluated coral reproductive activity, calcification, and bioerosion in two representative coral genera in three Central Mexican Pacific sites. We hypothesize that stressors associated to urban development will negatively affect coral performance while enhancing bioerosion. Despite moderate to high levels of nitrite, nitrate, and phosphate and highly variable sedimentation rates, coral performance was not hampered in any site. Coral growth in Pocillopora and Pavona corals exhibited typical growth rates (~ 6.6 gCaCO3 cm−2 year−1 and ~ 1.1 gCaCO3 cm−2 year−1, respectively) and colonies were reproductively active from March to November. However, 76.5% of all coral colonies were invaded by excavating sponges. In Pavona colonies, ~ 24.37% of total CaCO3 volume was removed by bioeroders. While coral performance is not hampered by the current nutrient levels and sedimentation regimes, these conditions may increase the abundance of bioeroders such as sponges, leading to higher bioerosion rates that compromise reef integrity and functionality. [ABSTRACT FROM AUTHOR]

Otolith analysis allows studying multiple aspects of fish biology, including age estimation; however, otoliths collected from avian stomach content have not been used to estimate the age of ingested fish. We evaluated the potential ability to estimate the age of Pacific sardine (Sardinops sagax) from otoliths collected from blue-footed booby (Sula nebouxii) stomach contents sampled in the Galapagos Islands. Blue-footed boobies were selected because they mostly forage close to their colony (<100 m) and were, therefore, more likely to have almost intact otoliths. To estimate age, we employed three previously developed methods for otoliths. We then related these estimates to the fish's standard length and compared these relations statistically using the Akaike Information Criterion (AIC) to determine which method was most parsimonious. We collected 32 otoliths in relatively good condition, of which we aged 31 with the surface-reading method, 26 with the otolith weight method, and 29 with the posterior otolith length method. Average ages obtained with the otolith methods were 5.6 ± 1.7 yr (± standard deviation), 5.7 ± 2.0 yr, and 3.9 ± 1.5 yr, respectively. Estimates obtained with the otolith weight method had the highest correlation with standard length and the lowest AIC values of the three suggesting it was the best method for aging. Our results indicate that aging otoliths extracted from bird stomachs are possible; however, their use depends on the availability of previously developed methods and how digested the fish are when the birds return to the colony. [ABSTRACT FROM AUTHOR]

This study establishes the dynamic biogeographic regions (DBGRs) of the Panama Bight (PB) based on remote-sensing reflectance (Rrs412 and Rrs488) of the MODIS-Aqua sensor and the sea-surface temperature (SST) and the concentration of chlorophyll a (Chl-a) derived from the same sensor. Monthly images with a spatial resolution of 4 km from the MODIS-Aqua sensor were used for July 2002–July 2020. To define the DBGR, the first standardized empirical orthogonal function (SEOF1) was calculated. Due to the low spatial variability in the PB, the number of DBGRs found with the analysis of the SST and Chl-a was lower than that found in the analysis of the Rrs. Therefore, the DBGRs of the PB were delineated based only on the study of the Rrs. The PB was divided into 11 DBGRs belonging to two provinces: oceanic and coastal. Five of the DBGRs were coastal, the others oceanic, including a transition one. The coastal regions were characterized by the highest averages of Chl-a and high SST. On the other hand, the regions located northeast of the PB (Panama Gulf, PB-transition, and Choco) were characterized by an average SST greater than 28°C and an average Chl-a between 0.8 and 1.0 mg·m−3. The DBGRs located further west (west and PB-west) showed an average SST greater than 28°C and the lowest concentrations of Chl-a. The DBGRs PB-east and PB-central, presented average SSTs of 26.7–27.1°C and average Chl-a concentrations lower than 0.5 mg·m−3. The south Ecuador DBGR presented the lowest average SST (<25 °C) and average Chl-a of 0.50 mg·m−3. Our approach allowed us to generate a dynamic regionalization of the PB, which most of the year has small SST and Chl-a gradients, making this an alternative to the homogeneous areas generated from the thermohaline structure. [ABSTRACT FROM AUTHOR]

Costa Rica hosts two renowned olive ridley (Lepidochelys olivacea) arribada beaches: Nancite and Ostional. In addition, the country hosts a third nascent arribada beach in Corozalito. We documented the frequency of arribada events in Corozalito (9°50′55.40″ N; 85°22′ 47.67″ W) from 2008 to 2021 and the abundance of egg-laying females during 12 arribadas. Moreover, we report on tag recaptures at Corozalito that were initially deployed at other nesting beaches in Costa Rica. Finally, we estimated incubation temperature, and performed quadrat and nest excavations to estimate hatching rates. We registered 29 arribadas at Corozalito since 2008, all between August and January. We estimated more than 150,000 olive ridleys nested during 12 arribadas from 2019 to 2021. Mean hatching success was 65% in quadrats and 59% for in situ marked nests. The mean incubation temperature was 32.3 °C. We found turtles tagged at other locations on the Pacific coast of Costa Rica nesting at Corozalito, providing evidence of philopatric plasticity. We suggest nascent arribada rookeries form rapidly via recruitment from regional turtle aggregations. Our findings show that hatching success is far higher at Corozalito than Ostional or Nancite. Continued monitoring of nesting dynamics at this site may shed light upon the mechanisms that rule how arribada beaches are born and evolve. Corozalito offers a unique opportunity to study and understand the arribada phenomenon and warrants official protection under official National Wildlife Refuge status. [ABSTRACT FROM AUTHOR]

Reef fish assemblages under fishing pressure generally exhibit a lower fish biomass, abundance, and size structure, which can be counteracted with the creation of marine protected areas (MPAs). The effectiveness of MPAs relies on enforcement and compliance, which is particularly challenging in developing countries with financial and socioeconomic limitations. By combining underwater visual surveys (UVS) and baited remote underwater video stations (BRUVS), we determined the abundance, size distribution, and biomass of economic (e.g., target and ornamental species) and ecological (e.g., small/large predators and herbivorous) indicator fish groups inside and outside a no-take MPA from the north Pacific coast of Costa Rica. The biomass of economic fish groups was not affected by protection, yet overall abundance and size distribution of fishes differed between no-take and open-fishing zones. These results suggest that although illegal fishing may be occurring inside the MPA, there are at least partial benefits of protection on particular groups within the fish assemblage. Herbivores and ornamental fishes, two groups that are targeted by the artisanal compressor fishery and by the aquarium trade, respectively, had higher biomass and were more abundant inside the no-take MPA. Additionally, large shark species (e.g., Galeocerdo cuvier, Carcharhinus leucas, C. limbatus) were only present inside the MPA. Habitat quality was particularly important for ornamental fishes which showed higher biomass in areas with high coral cover. Our study adds to a growing body of evidence suggesting that, even with limited enforcement, MPAs still provide ecological benefits for reef fish assemblages. [ABSTRACT FROM AUTHOR]

Echinoderms are a highly diverse group and one of the most conspicuous in the deep sea, playing ecological key roles. We present a review about the history of expeditions and studies on deep-sea echinoderms in Costa Rica, including an updated list of species. We used literature and information gathered from the databases of the California Academy of Sciences, the Benthic Invertebrate Collection of the Scripps Institution of Oceanography, the National Museum of Natural History, the Museum of Comparative Zoology and the Museo de Zoología from the Universidad de Costa Rica. A total of 124 taxa (75 confirmed species) have been collected from the Costa Rican deep sea, 112 found in the Pacific Ocean, 13 in the Caribbean Sea, and one species shared between the two basins. We report 22 new records for the Eastern Tropical Pacific, 46 for Central American waters, and 58 for Costa Rica. The most specious group was Ophiuroidea with 37 taxa, followed by Holothuroidea (34 taxa), Asteroidea (23 taxa), Echinoidea (17 taxa), and Crinoidea (11 taxa). The highest number of species (64) was found between 800 m and 1200 m depth. Only two species were found deeper than 3200 m. Further efforts on identification will be required for a better comprehension of the diversity of deep-sea echinoderms. Limited research has been done regarding the biology and ecology of deep-sea echinoderms in Costa Rica, so additional approaches will be necessary to understand their ecological functions.

Morphological plasticity in hermatypic corals is an adaptive response that helps corals withstand biotic and abiotic stressors, but also, can influence the structural complexity of coral reef habitats. The influences of biotic factors (e.g., bioerosion) on coral plasticity may threaten the skeletal structure, reducing coral's ability to compete for space and survive. The present study reports intense infestation of Chaetopterids, a tube-dwelling polychaetes in Porites lobata colonies, and evaluates their effects on coral growth and morphology by comparing skeletal features (extension rate, skeletal density, and calcification rate) before and after polychaete outbreak. The results showed significant differences in all coral skeletal features of P. lobata before and after polychaete infestation. After-infestation, coral growth decreased an average of 42% and 46% in annual extension and calcification rates, respectively. Sclerochronology analysis displayed partial mortality and stress-signature bands, which coincided with the cold 2010–2011 La Niña period, when polychaete infestation was potentially initiated. The data reveals that P. lobata coral appears capable of modifying its growth strategy (optimal plasticity), yet polychaete infestation can negatively affect coral accretion rates and weaken coral structural stability, in turn compromising their long-term contribution to coral reef habitats maintenances in the eastern tropical Pacific. [ABSTRACT FROM AUTHOR]

The Panama Low-Level Jet (PLLJ) is the inter-isthmic jet closest to the equator, whose activation modifies circulation, sea surface temperature, and climate in most Eastern Tropical Pacific off Colombia. Through analysis of 26 years (1992-2018) of sea wind data, the jet extent and its main frequencies of variability were determined, in addition to its relationship with phenomena of climatic variability. The area of direct influence of the jet was estimated to be 59,295.34 km², being located between 4°37'48" and 9°0'0"N. The PLLJ has activated annually from December to April with intense intra-seasonal variability (with frequencies between one to five months) and inter-annual perturbations associated with El Niño Southern Oscillation (ENSO) events. During warm ENSO events, the PLLJ activity lasts around two months more (from mid-November to the end of May), and its spatial extent increases southerly, reaching around 2°N. Additionally, during warm ENSO years, there is an extemporaneous activation of PLLJ in the boreal summer, possibly linked to the intensification of the North Trade Winds over the Caribbean basin in the middle of the year. The entry of Caribbean winds in unusual seasons changes the seasonal pattern of the PLLJ and increases its influence in the Eastern Tropical Pacific during the warm ENSO phases. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the growth and survival of juveniles of the winged oyster Pteria sterna, culture in two types of baskets manufactured with local materials. These were ‘one floor baskets’ (OFB) and ‘three floor baskets’ (TFB), hung from two ‘long lines’ in two study sites, Ayangue and Palmar, Province of Santa Elena, Ecuador, over a five months experimental culture period. Environmental variables monitored included total particulate matter and its organic and phytoplanktonic fraction (chlorophyll a), temperature, and dissolved oxygen. Individuals showed an initial length, height (dorso-ventral) and thickness (inter-valvar) shell axis of 18.7 ± 0.32; 18.2 ± 0.29 and 7.4 ± 0.18 mm, respectively; and the soft tissue mass, shell mass and total mass were: 1.03 ± 0.04; 0.11 ± 0.005; 1.14 ± 0.04 g, respectively. At the end of the period, biometric and survival parameters were recorded. The individuals cultured in Ayangue using TFB showed increments in shell, soft tissues and total mass that were significantly higher than those from the OFB. Similar results, but with lower increments, were obtained by the individuals cultivated at Palmar site. The ANOVA II showed that the site, type of basket and the interaction between the two had a significant effect on the growth of the oysters. Survival exceeded 80% at both sites and for both basket types, but no significant differences were observed between site and basket type. Considering the growth and survival obtained for both types of baskets, we recommend the TFB baskets for winged oyster cultivation in these regions.

Introduction: The Gulf of Nicoya is the most important estuary on the Pacific coast of Costa Rica. Information on the presence of soft corals is scattered in the literature and in museum collections. Objective: To provide a list of soft corals reported for the estuary. Methods: We compiled the literature (2002-2020) and of the specimens deposited at the Museum of Zoology, University of Costa Rica. Results: Thirty species have been reported for the estuary (Clavulariidae, Gorgoniidae and Plexauridae). Most were collected on the eastern coast of the Nicoya Peninsula, and several species were described based on estuary specimens. Conclusion: The 30 species represent 79 % of those reported for Costa Rica. Despite this relatively high percentage, the sampling effort has been modest and other sites within the estuary should be explored.

Introduction: Estimates of contemporary connectivity of the broadcast spawning coral Pocillopora verrucosa between multi-use marine protected areas (MUMPAs) are required to assess MUMPA effectiveness and their ability to enhance resilience against disturbances. Objective: To determine the genetic structure and connectivity patterns between P. verrucosa demes inside the Gulf of California and evaluate the role and effectiveness of established MUMPAS in their protection and resilience. Methods: We assessed P. verrucosa connectivity along its peninsular range (~350 km), including five locations and three MUMPAs in the Gulf of California using six microsatellite genetic markers. Results: Population structure was significant (FST = 0.108***) when demes included clonal replicates; however, when these clones were removed from the analysis, the sexual individuals comprised a metapopulation panmixia (FST = 0.0007 NS). To further understand connectivity patterns, an assignment test was carried out which identified ten recent between-deme migrants with a mean dispersal distance of 116.6 km (± 80.5 SE). No longdistance dispersal was detected. These results highlight the ecological importance of the Bahía de La Paz region, including Archipiélago de Espíritu Santo MUMPA. This region, located at the center of the species peninsular range, exports larva to downstream sink demes such as the Loreto (northwardly) and Cabo Pulmo (southwardly) MUMPAs. Of importance, inter-MUMPA spacing was larger than the mean larval dispersal by ~56 km, suggesting thar the designation of intermediate 'no-take' zones would enhance short-distance connectivity. Conclusion: This study contributes as a baseline for policymakers and authorities to provide robust strategies for coral ecosystem protection and suggest that protection efforts must be increased towards peninsular intermediate reefs to promote metapopulation resilience from natural and anthropogenic factors. [ABSTRACT FROM AUTHOR]