Small-scale fisheries of Peru: a major sink for marine turtles in the Pacific

1. Over the last few decades, evidence of marine vertebrate bycatch has been collected for a range of industrial fisheries. It has recently been acknowledged that large impacts may also result from similar interactions with small-scale fisheries (SSF) due largely to their diffuse effort and large number of vessels in operation. Marine mammals, seabirds, turtles as well as some shark species have been reported as being impacted by SSF worldwide. 2. From 2000 to 2007, we used both shore-based and onboard observer programmes from three SSF ports in Peru to assess the impact on marine turtles of small-scale longline, bottom set nets and driftnet fisheries. 3. We reported a total of 807 sea turtles captured, 91Æ8% of which were released alive. For these three sites alone, we estimated c. 5900 turtles captured annually (3200 loggerhead turtles Caretta caretta, 2400 green turtles Chelonia mydas, 240 olive ridleys Lepidochelys olivacea and 70 leatherback turtles Dermochelys coriacea). 4. SSF in Peru are widespread and numerous (\u3e100 ports, \u3e9500 vessels, \u3e37 000 fishers), and our observed effort constituted c. 1% of longline and net deployments. We suggest that the number of turtles captured per year is likely to be in the tens of thousands. Thus, the impacts of Peruvian SSF have the potential to severely impact sea turtles in the Pacific especially green, loggerhead and leatherback turtles. 5. Implications of the human use of turtle products as ‘marine bushmeat’ are also raised as an important issue. Although such utilization is illegal, it is difficult to foresee how it can be managed without addressing the constraints to the livelihoods of those depending almost entirely on coastal resources. 6. Syntheses and applications. Our analysis demonstrates that, despite logistical challenges, it is feasible to estimate the bycatch per unit of effort in SSF by combining methods that account for fishing effort and bycatch, such as using onboard and shore-based observers. We highlight sea turtle bycatch in SSF in the southeast Pacific as a major conservation concern but also suggest possible paths for mitigation

An evaluation of information sharing schemes to identify what motivates fishers to share catch information

Funding This work has been funded by Science Foundation Ireland through a Starting Investigator Research grant number 18/SIRG/5554.Peer reviewedPublisher PD

Distribution and Habitat Use of a Cryptic Small Cetacean, the Burmeister's Porpoise, Monitored From a Small-Scale Fishery Platform

There is widespread evidence that small-scale fisheries (SSF) bycatch threatens many populations of small cetaceans, yet conservation efforts are often limited by a lack of basic knowledge regarding their abundance, distribution, and habitat use. Here, we used passive acoustic monitoring from an SSF platform-of-opportunity to better characterize the distribution and habitat use of small cetaceans in northern Peru, focussing on the little-known Burmeister's porpoise Phocoena spinipinnis. From 2009 to 2012, acoustic click detectors (C-PODs) were attached to fishing nets for the duration of 116 fishing sets (30 fishing trips). Dolphins (unspecified delphinids) and porpoises were recorded around 71 and 22% of fishing sets, respectively. The probability of occurrence and buzzing behavior (a proxy for foraging), and time spent, were linked to both static and dynamic environmental variables to examine the drivers of habitat use. Dolphin activity was spread evenly throughout the fishing area and was not linked to any habitat variables. In contrast, porpoises were detected in neritic waters, and habitat models performed well, identifying preferences for shallow (<200 m depth) and cooler (17–18°C) waters, close (<50 km) to shore. The high bycatch rate of small cetaceans in Peruvian SSF gave us the unique opportunity to investigate the link between bycatch and cetacean activity around vessels. We found a positive relationship between the likelihood of a bycatch event and acoustic presence for both dolphins and porpoises, however as we did not know the timing of entanglement, we could not link vocalization rates to mortality events. Nonetheless, as small cetaceans (particularly dolphins) frequently encounter fishing boats, the likelihood of entanglements may be reduced through effective efforts to alert animals to the presence of the net, either acoustically (using acoustic alarms) or visually. This study demonstrates that passive acoustic monitoring from a fisheries platform can provide insights into the distribution and habitat use of small cetaceans at relatively low cost, and is likely to be suitable in regions with low monitoring effort and high fishing pressure

Mercury levels in the Smooth Hammerhead Shark Sphyrna zygaena (Carcharhiniformes: Sphyrnidae) from Northern Peru

El tiburón martillo (Sphyrna zygaena (Linnaeus, 1758)) es una de las especies de elasmobranquios más utilizada para consumo humano en el Perú. Sin embargo, se desconoce los niveles de mercurio que contiene su carne. Este trabajo tuvo como objetivo evaluar los niveles de mercurio hallados en el músculo del tiburón martillo y su posible implicancia en la salud humana. Además, determinar si existe una correlación entre el tamaño del tiburón y los niveles de mercurio. Analizamos 27 muestras de músculo de neonatos y juveniles capturados en el norte del Perú. La concentración de mercurio varió entre 0.13 – 0.85 mg kg-1 peso húmedo. Se encontró una relación negativa y significativa entre el tamaño corporal del tiburón y los niveles de mercurio. Este trabajo representa el primer estudio que evalúa los niveles de mercurio de tiburones en el Perú. Si bien los valores hallados fueron menores a lo recomendado por la Organización Mundial de la Salud (< 1 mg kg-1), se recomienda ampliar este tipo de estudios en individuos adultos de tiburón, así como en otros recursos hidrobiológicos de consumo humano.The smooth hammerhead shark Sphyrna zygaena (Linnaeus, 1758) is one of the elasmobranch species most used for human consumption in Peru. However, the level of mercury in hammerhead muscle tissue is unknown. This study assessed the level of mercury found in the muscle of hammerhead sharks and its relation with human health. Moreover, we evaluated the relationship between shark body size and mercury levels. We analyzed 27 muscle samples of neonates and juveniles captured in northern Peru. Mercury concentrations varied between 0.13 and 0.86 mg kg-1 wet weight. Moreover, we found a negative and significant relationship between shark body size and mercury levels. This study represents the first evaluation of mercury levels of sharks in Peru. Although the values found do not exceed levels recommended by the World Health Organization (< 1 mg kg-1), we recommend expanding this study to include other size classes of sharks as well as other marine resources used for human consumption

Preliminary analysis of the feeding habits of batoids from the genera Mobula and Myliobatis in northern Peru

This study provides baseline information on the feeding habits of five batoid species from the genera Mobula and Myliobatis sampled from the small-scale driftnet fishery in northern Peru. The diets of Mobula mobular, Mobula munkiana and Mobula thurstoni consisted mainly of euphausiids. Dietary niche breadth indicated a pelagic feeding behaviour of a specialist and a trophic level of a secondary predator for both M. mobular and M. munkiana. In contrast, Myliobatis chilensis and Myliobatis peruvianus consumed mostly gastropods and crustaceans. Dietary niche breadth indicated a feeding behaviour of a benthic specialist and a trophic level of a secondary predator for Myliobatis chilensis

USO DE TRES MÉTODOS PARA EVALUAR EL MANATI AMAZÓNICO (Trichechus inunguis) EN EL ÁREA DE CONSERVACIÓN REGIONAL TAMSHIYACU TAHUAYO, LORETO, PERÚ

The Amazon manatee (Trichechus inunguis) is endemic to the Amazon Basin, with limited information on population dynamics and currently listed as Vulnerable by the Red List of the International Union for the Conservation of Nature (IUCN). The aim of this study was to compare three methodologies: visual detection (VD), side scan sonar technology (SBL), and surveys to local communities; to detect the presence of the Amazonian manatee and assess the use of these methods for future studies along the species distribution range. The study was carried out within the Tamshiyacu Tahuayo Communal Regional Conservation Areain Iquitos, Peru. The VD resulted in zero sightings at both seasons after a sampling effort of 30 and 29 hours during the rainy and dry seasons respectively. After using the SBL, two individuals were recorded in August, after a total sampling of 103.38 km in the dry season (0.02 ind/km). Surveys to artisanal fishermen in three neighboring communities indicated the presence of manatees and the perception of reduction in sightings within the protected area during 2018 (previous year of this study). We discussed the advantages and disadvantages of each methodology, the logistics associated with its use in complex habitats, and its effectiveness and potential use to detect manatees in future studies in the area.El manatı́ amazónico (Trichechus inunguis) es endémico de la cuenca amazónica, cuenta con una limitada información de dinámica poblacional y actualmente está categorizado como Vulnerable por la Lista Roja de la Unión Internacional para la Conservación de la Naturaleza (UICN). El presente estudio tiene como objetivo comparar tres metodologıá s: registro visual (RV), sonar de barrido lateral (SBL) y encuestas en comunidades locales; para detectar la presencia de la especie y evaluar su aplicación para futuros estudios en su zona de distribución. El estudio fue llevado a cabo dentro del Área de Conservación Regional Comunal Tamshiyacu Tahuayo en Iquitos, Perú. El RV resultó en cero avistamientos en ambas estaciones luego de un esfuerzo de muestreo de 30 y 29 horas en la estación creciente y vaciante respectivamente. Tras el uso del SBL, dos individuos se registraron en agosto, luego de un recorrido total de 103,38 km en la estación vaciante (0,02 ind/km). Las encuestas realizadas a los pescadores artesanales en tres comunidades aledañas indicaron lapresencia de la especie, ası́ como la percepción de una reducción en avistamientos en el área protegida durante el 2018 (año previo a las encuestas).Se discute las ven‑ tajas y desventajas de cada metodología , la logística asociada a su uso en hábitats complejos, y su efectividad y uso potencial para la detección de manatíes en futuros estudios en la zon

La pesquería con arpón de peces picudos (Xiphiidae e Istiophoridae) en El Ñuro, Perú: Bases de una pesquería olvidada: The harpoon fishery for billfishes (Xiphiidae and Istiophoridae) from El Ñuro, Perú: Basis of a forgotten fishery

La pesca con arpón es un método ancestral de alta selectividad, desplazado en los últimos años por aparejos mecanizados que han logrado maximizar las capturas. A pesar de ello, en algunas partes del mundo, se sigue empleando esta práctica para la captura de grandes pelágicos como los peces picudos. Los reportes de la pesquería con arpón son cada vez más escasos y en el Perú, el último registro de desembarques de picudos capturados con arpón se remonta al año 1999. El objetivo de este estudio fue proveer información de base sobre esta pesquería en la caleta El Ñuro, a partir de muestreos mensuales de desembarques durante el 2019. Cuatro de las cinco especies reportadas para el Perú fueron registradas: Xiphias gladius, Kajikia audax, Makaira nigricans e Istiompax indica. De estas, el pez espada (X. gladius) compuso el 95% de los desembarques en términos de abundancia. Durante la temporada fría (mayo-noviembre) se reportaron los mayores desembarques, con picos en la captura efectiva por unidad de esfuerzo entre julio y agosto (>0,15 ind.hfp-1). Al menos el 96% de los individuos de X. gladius desembarcados fueron considerados adultos. Se concluye que la pesquería con arpón en El Ñuro tuvo una marcada temporada de pesca durante el invierno 2019, estuvo compuesta sobre todo por X. gladius y presentó gran selectividad en función a las tallas capturadas. Se precisa de estudios complementarios más detallados en el Norte del Perú con la finalidad de evaluar las opciones más adecuadas que aseguren su sostenibilidad en el tiempo

One-year outcomes of the ARTISAN-SNM study with the Axonics System for the treatment of urinary urgency incontinence

Aims: Sacral neuromodulation (SNM) is a guideline-recommended treatment for voiding dysfunction including urgency, urge incontinence, and nonobstructive retention as well