First field-based estimate of Antillean manatee abundance in the San Pedro River system suggests large errors in current estimates for Mexico

Fluvial-lagoon systems like the San Pedro River, a tributary of the Usumacinta River, are important habitats for Antillean manatees. These systems are characterized by complex watercourses that contain water with high turbidity levels, which have historically limited manatee studies in hydrological...

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Päätekijät: Puc-Carrasco, Gissel, Morales-Vela, Benjamín, Olivera-Gomez, León David, González-Solís, David
Aineistotyyppi: Online
Kieli:eng
Julkaistu: Iniversidad Autónoma de Baja California 2017
Linkit:https://www.cienciasmarinas.com.mx/index.php/cmarinas/article/view/2704
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id oai:cienciasmarinas.com.mx:article-2704
record_format ojs
institution Ciencias Marinas
collection OJS
language eng
format Online
author Puc-Carrasco, Gissel
Morales-Vela, Benjamín
Olivera-Gomez, León David
González-Solís, David
spellingShingle Puc-Carrasco, Gissel
Morales-Vela, Benjamín
Olivera-Gomez, León David
González-Solís, David
First field-based estimate of Antillean manatee abundance in the San Pedro River system suggests large errors in current estimates for Mexico
author_facet Puc-Carrasco, Gissel
Morales-Vela, Benjamín
Olivera-Gomez, León David
González-Solís, David
author_sort Puc-Carrasco, Gissel
title First field-based estimate of Antillean manatee abundance in the San Pedro River system suggests large errors in current estimates for Mexico
title_short First field-based estimate of Antillean manatee abundance in the San Pedro River system suggests large errors in current estimates for Mexico
title_full First field-based estimate of Antillean manatee abundance in the San Pedro River system suggests large errors in current estimates for Mexico
title_fullStr First field-based estimate of Antillean manatee abundance in the San Pedro River system suggests large errors in current estimates for Mexico
title_full_unstemmed First field-based estimate of Antillean manatee abundance in the San Pedro River system suggests large errors in current estimates for Mexico
title_sort first field-based estimate of antillean manatee abundance in the san pedro river system suggests large errors in current estimates for mexico
description Fluvial-lagoon systems like the San Pedro River, a tributary of the Usumacinta River, are important habitats for Antillean manatees. These systems are characterized by complex watercourses that contain water with high turbidity levels, which have historically limited manatee studies in hydrological basins on the eastern coast of Mexico. This study aimed to estimate manatee density in the San Pedro River system and to determine how this density varies with changes in water level. Density was estimated using counts detected by side-scan sonar (SSS). Two monthly navigation sessions were conducted from January to June 2016. Each session consisted of running 3 consecutive boat surveys along a 23-km-long transect at a speed of 10 km/h. Manatees were detected with a Humminbird SSS unit. A total of 471 manatees were detected, of which 46 (10%) were calves and 425 (90%) adults. Four different calves were identified. Mean density was 21.7 manatees per square kilometer, fluctuating between 3.7 and 43.3 manatees per square kilometer. Changes in manatee density were attributable to variations in water level, which allow or restrict manatee access to the different water bodies that make up the San Pedro River system. We estimated that 28 manatees were present in the study area. Manatee densities were surprisingly low. It is thus urgent to continue monitoring studies using SSS and obtain an updated estimation of manatee population size in the hydrological basins on the eastern coast of Mexico, which is considered to be the most important population in the country. 
publisher Iniversidad Autónoma de Baja California
publishDate 2017
url https://www.cienciasmarinas.com.mx/index.php/cmarinas/article/view/2704
_version_ 1797332411320631296
spelling oai:cienciasmarinas.com.mx:article-27042024-04-05T20:27:38Z First field-based estimate of Antillean manatee abundance in the San Pedro River system suggests large errors in current estimates for Mexico La primera estimación de la abundancia de manatí antillano en el sistema del río San Pedro, basada en datos de campo, sugiere grandes errores en las estimaciones actuales para México Puc-Carrasco, Gissel Morales-Vela, Benjamín Olivera-Gomez, León David González-Solís, David Fluvial-lagoon systems like the San Pedro River, a tributary of the Usumacinta River, are important habitats for Antillean manatees. These systems are characterized by complex watercourses that contain water with high turbidity levels, which have historically limited manatee studies in hydrological basins on the eastern coast of Mexico. This study aimed to estimate manatee density in the San Pedro River system and to determine how this density varies with changes in water level. Density was estimated using counts detected by side-scan sonar (SSS). Two monthly navigation sessions were conducted from January to June 2016. Each session consisted of running 3 consecutive boat surveys along a 23-km-long transect at a speed of 10 km/h. Manatees were detected with a Humminbird SSS unit. A total of 471 manatees were detected, of which 46 (10%) were calves and 425 (90%) adults. Four different calves were identified. Mean density was 21.7 manatees per square kilometer, fluctuating between 3.7 and 43.3 manatees per square kilometer. Changes in manatee density were attributable to variations in water level, which allow or restrict manatee access to the different water bodies that make up the San Pedro River system. We estimated that 28 manatees were present in the study area. Manatee densities were surprisingly low. It is thus urgent to continue monitoring studies using SSS and obtain an updated estimation of manatee population size in the hydrological basins on the eastern coast of Mexico, which is considered to be the most important population in the country.  Los sistemas fluviolagunares como el río San Pedro, tributario del río Usumacinta, son hábitats muy importantes para el manatí antillano. Estos sistemas se caracterizan por tener complejos cursos de agua con altos niveles de turbidez, que históricamente han dificultado el estudio de los manatíes en las cuencas hidrológicas de la costa oriental de México. Los objetivos de este estudio fueron estimar la densidad de manatíes en el sistema río San Pedro y saber cómo varía esta densidad con los cambios en el nivel del agua. El método para estimar la densidad se basó en el uso de un sonar de barrido lateral (SBL). Se realizaron 2 sesiones de navegación por mes, de enero a junio de 2016. Cada sesión consistió en 3 recorridos consecutivos sobre un transecto de 23 km de largo a una velocidad de 10 km/h. La detección de los manatíes se realizó con un SBL Humminbird. Se detectaron un total de 471 manatíes, de los cuales 46 (10%) correspondieron a crías y 425 (90%) a adultos. Cuatro crías distintas fueron identificadas. La densidad promedio fue de 21.7 manatíes por kilómetro cuadrado, con fluctuaciones de 3.7 a 43.3 manatíes por kilómetro cuadrado. Los cambios en la densidad de manatíes se atribuyen a las variaciones en el nivel del agua, que permiten o restringen el acceso de los manatíes a los distintos cuerpos de agua que componen el sistema del río San Pedro. Se estimó un total de 28 manatíes en el área de estudio. Los valores de densidad de manatíes fueron inesperadamente bajos. Por tanto, es urgente continuar con estos estudios usando el SBL para obtener una estimación actual del tamaño de la población de manatíes en las cuencas hidrológicas de la costa oriental de México, población considerada como la más importante en el país. Iniversidad Autónoma de Baja California 2017-12-22 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Peer-reviewed Article Artículo Arbitrado application/pdf text/xml text/xml https://www.cienciasmarinas.com.mx/index.php/cmarinas/article/view/2704 10.7773/cm.v43i4.2704 Ciencias Marinas; Vol. 43 No. 4 (2017); 285–299 Ciencias Marinas; Vol. 43 Núm. 4 (2017); 285–299 2395-9053 0185-3880 eng https://www.cienciasmarinas.com.mx/index.php/cmarinas/article/view/2704/1952 https://www.cienciasmarinas.com.mx/index.php/cmarinas/article/view/2704/420420610 https://www.cienciasmarinas.com.mx/index.php/cmarinas/article/view/2704/420420786 Copyright (c) 2017 Ciencias Marinas https://creativecommons.org/licenses/by/4.0