Varamiento de mega vertebrados marinos en la costa norte de Perú (2017-2018)

Abstract

Los eventos de varamientos de mega vertebrados se están reportando con mayor frecuencia en los últimos años. La costa peruana no es ajena a este tipo de eventos. Diversas limitantes como escaso presupuesto, inaccesibilidad a la zona de ocurrencia y monitoreos discontinuos, imposibilitan investigaciones sistemáticas. A partir del 2014, el Instituto del Mar del Perú (IMARPE) viene realizando monitoreos periódicos de mortandad de fauna marina varada en el litoral norte con el objetivo de caracterizar estos eventos. Este estudio analiza los datos obtenidos durante los monitoreos del 2017 y 2018 en las Regionesde Lambayeque (06°22’S-07°10’S), Piura (4°50’S-06°22’S) y Tumbes (3°23’S-4°50’S), contabilizando 7.014 animales varados entre aves, tortugas y mamíferos marinos, siendo las especies más afectadas: lobo marino chusco Otaria byronia (50%), piquero peruano Sula variegata (14%), pelícano peruano Pelecanus thagus (13%), tortuga verde del Pacífico este Chelonia mydas agassizii (4%), marsopa espinosa Phocoena spinipinnis (4%), piquero patas azules Sula nebouxii (3%), delfín común de hocico largo Delphinus capensis (3%) y guanay Phalacrocorax bougainvillii (2%). Las principales zonas de ocurrencia fueron el norte deLambayeque y sur de Piura. Se determinó 5% (n= 331) de causas de varamiento, mayor porcentaje fue de origen antrópico, principalmente relacionadas a interacción con pesquerías, reflejando el conflicto entre los mega vertebrados marinos y la flota pesquera. Es necesario contar con este tipo de estudios que amplíen el panorama sobre lo que sucede en el medio marino, para establecer medidas correctivas que mitiguen los varamientos por causas de origen humano, sobre todo en especies clave amenazadas de extinción y protegidas por la legislación peruana y acuerdos internacionales adoptados por el Perú.

Entomofauna cadavérica en vertebrados marinos varados en la costa central del Perú

“…The chordates with the highest number of stranded carcasses in the present study were a mammal (O. flavescens), and three species of birds (S. variegata, P. thagus and P. brasilianus). Our results are consistent with Chauca et al (2021) who recorded data on the stranding of marine mega vertebrates on the north coast of Peru (2017Peru ( -2018, the most abundant species being O. flavescens (50%), S. variegata (14%) and P. thagus (13 %). Among the causes of stranding of carcasses, these authors described a higher percentage of anthropic origin, mainly associated with interaction with fishing activities, demonstrating a conflict between marine vertebrates and fishing boats (Portflitt-thagus -O. flavescens more associated with each other, and the entomofauna of S. variegata determined with the index of presence/absence of Jaccard (Fig.…”

“…The results of this study show that based on the total number of corpses and the richness of the stranded species, ornithological fauna was more frequently found in comparison to mammals. In regard to corpse number, in their study Chauca et al (2021) reported that the total number of corpses for the northern zone of Peru, specifically for the Regions of Lambayeque (06°22'S-07°10'S), Piura (4°50'S-06°22'S) and Tumbes (3°23'S-4°50'S), was higher for mammals (60.6%) than for birds (39.4%). On the other hand, when evaluated based on species richness, a greater number of birds (n= 19; 67.85%) was observed compared to mammals (n= 9; 32.15%).…”

“…These species are more associated with fresh-swollen states and active decomposition. L. sericata is a Holarctic necrophagous Chauca et al, 2021). Portflitt-Toro et al (2018) reported that the birds most frequently stranded were S. variegata (30%), P. bougainvillii (22%), Larus dominicanus (17%), P. thagus (9%) and S. humboldti (8%), in the Coastal System of Coquimbo, Chile.…”

“…When comparing our results with previously published studies, it is evident that based on the number of species the Orders most frequently found were Cetartiodactyla (n= 7), Suliformes (n= 6) and Procellariformes (n= 6), being Carnivora, Suliformes and Pelecaniformes based on abundance. Finally, the Delphinidae (n= 6) and Laridae (n= 4) families had the highest number of species of vertebrates stranded in the northern zone of Peru, (Chauca et al, 2021).…”

“…Each of the carcasses of birds and mammals evaluated were identified at the species level using specialized scientific literature for their taxonomic identification (Bello, 2005;Barrio & Guillén, 2014;Senner & Angulo, 2014;Chauca et al, 2021), which was corroborated by experts.…”