Complementary methods to estimate population size of Antillean Manatees (Sirenia: Trichechidae) at Ciénaga de Paredes, Santander, Colombia

Arévalo-González, Gloria Katherine; Castelblanco‐Martínez, Delma Nataly; Sánchez-Palomino, Pedro; López-Arévalo, Hugo Fernando; Marmontel, Míriam

doi:10.11609/jott.o3156.5830-7

Cited by 12 publications

(12 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As none of the methods are infallible, collecting multiple types of evidence increases confidence in the presence/absence data. Although we couldn't confirm any visual detections with images from the side-scan sonar (or vice versa), previous research has validated the use of side-scan sonar to detect manatees in turbid waters (Gonzalez-Socoloske et al, 2009; Gonzalez-Socoloske & Olivera-Gomez, 2012; Arévalo-González et al, 2014; Brice, 2014).…”

Section: Discussionmentioning

confidence: 60%

How to detect an elusive aquatic mammal in complex environments? A study of the Endangered Antillean manateeTrichechus manatus manatusin French Guiana

Castelblanco‐Martínez¹,

Reis

Thoisy

2017

Oryx

Self Cite

View full text Add to dashboard Cite

The Antillean manatee Trichechus manatus manatus is a cryptic mammal that inhabits, among other areas, murky rivers and estuaries of Central and South America. The difficulty in detecting and counting manatees is an obstacle to monitoring their population status, as traditional count sampling is unsuitable. We conducted a quantitative analysis of the distribution and abundance of the manatee across its known range in the rivers and estuaries of French Guiana, based on data from a range-wide line transect visual survey combined with a side-scan sonar survey, identification of feeding sites, and silent observations at fixed points. A total effective effort of 248 hours and 1,129 km of boat survey was completed. We used two relative abundance indices: the combined encounter rate, which combines encounters per km from either visual or side-scan sonar surveys, and the global detection index, which is defined as the sum of all evidence per unit time. Manatees were detected in all nine study units. Niche modelling was used to analyse the space selection by manatees, and helped to detect differential use of habitats according to the season. The model predicted that coastal areas are used more extensively during the dry season. In the absence of better techniques to detect wild manatees in complex habitats this monitoring protocol may be relevant and replicable in hydrological systems where manatee detectability is constrained by biogeographical characteristics.

show abstract

Section: Discussionmentioning

confidence: 60%

How to detect an elusive aquatic mammal in complex environments? A study of the Endangered Antillean manateeTrichechus manatus manatusin French Guiana

Castelblanco‐Martínez¹,

Reis

Thoisy

2017

Oryx

Self Cite

View full text Add to dashboard Cite

show abstract

“…The field measurements conducted in this study contributed to the detailed description of the seasonal/spatial distributions of water surface temperature, salinity, and the maximum estuarine extent into the river (>17 km upstream). Side‐scan sonar was confirmed as a valuable tool for manatee detection and was used to complement visual sightings and enhance specific information on the species' current distribution (Arévalo‐González et al, 2014; Gonzalez‐Socoloske & Olivera‐Gómez, 2012; Puc‐Carrasco et al, 2016, 2017; Serrano et al, 2017).…”

Section: Discussionmentioning

confidence: 99%

Spatial and seasonal variations in surface water temperature and salinity in the Mexico‐Belize riverine estuary: Possible comfort conditions for manatees?

Callejas-Jiménez

Alcérreca‐Huerta

Morales‐Vela

et al. 2021

Marine Mammal Science

View full text Add to dashboard Cite

The Mexican Caribbean and Belize are home to one of the largest populations of Caribbean manatees (Trichechus manatus manatus). However, the transboundary Hondo River estuary is less examined compared to the surrounding protected areas. This paper provides a quantitative description of the spatial and temporal variability in abiotic factors and manatee distribution throughout the Hondo River estuary, with monthly field measurements during 2018–2019. Simultaneously, visual observations and side‐scan sonar detection were implemented, with 84 manatee sightings reported (calves 11.9%, noncalves 88.1%). Heatmap and frequency analyses showed that most manatee sightings occurred at the riverine estuary limit, the confluences between the river and the bay into which it flows. The surface water temperature and salinity ranged 28°C ≤ T ≤ 32°C and 0.5 PSU ≤ S ≤ 4.5 PSU for ~72% of the manatees identified, potentially describing locally preferred conditions for manatees. During the regional mid‐summer drought, higher temperature (31.5°C), salinity (18 PSU), and estuary extent (17.6 km) were recorded, including the maximum peak of manatee sightings (~31%). The roles of these abiotic factors are discussed as tentative environmental comfort conditions for manatees that could reduce their energy and maintenance costs. The identification of preferred conditions could broaden perspectives on how manatees interact with their habitats.

show abstract

“…Through the engagement of local stakeholders in population assessments, Local Ecological Knowledge (LEK) has proved a valuable resource to investigate population ecology in fellow sirenians; the Amazonian manatee Trichechus inunguis (Franzini et al, 2013;Sousa et al, 2013), Antillean manatee Trichechus manatus (Arevalo-Gonzalez et al, 2014) and West African manatee Trichechus senegalensis (Mayaka et al, 2013). LEK has also been used to examine the presence of D. dugon populations across their range in developing countries such as Malaysia (Rajamani, 2013;Rojchanaprasart et al, 2014), Myanmar (Ilangakoon and Tun, 2007) and Mayotte Island (Pusineri et al, 2013).…”

Section: Discussionmentioning

confidence: 99%

Reasons for seagrass optimism: Local ecological knowledge confirms presence of dugongs

Cullen-Unsworth

Jones

Seary

et al. 2018

Marine Pollution Bulletin

View full text Add to dashboard Cite

Dugongs (Dugong dugon) depend on seagrass meadows for food. As such seagrass and dugong conservation should go hand in hand. Assessing dugong populations is notoriously challenging. In the most resource dependent communities Local Ecological Knowledge (LEK) is generally high and can provide an alternative to the use of expensive ecological surveys to understand dugong populations and support associated resource management decisions. Residents of the Wakatobi National Park (WNP), SE Sulawesi, Indonesia are highly dependent on marine resources for livelihoods and correspondingly LEK is high. Here LEK documents the presence of D. dugon in the WNP and infers changes in population size. Interviews with local residents in 2012-2013 revealed 99 sightings of dugongs since 1942, 48 of which occurred between 2002 and 2012, with 79.82% of respondents having seen a dugong. Declines in the frequency of sightings within the lifetime of several respondents were reported, respondents speculating that populations are reduced. This information can guide further cooperative research and conservation efforts for the protection of a vulnerable species and the seagrass habitat on which it depends.

show abstract

Complementary methods to estimate population size of Antillean Manatees (Sirenia: Trichechidae) at Ciénaga de Paredes, Santander, Colombia

Cited by 12 publications

References 4 publications

How to detect an elusive aquatic mammal in complex environments? A study of the Endangered Antillean manateeTrichechus manatus manatusin French Guiana

How to detect an elusive aquatic mammal in complex environments? A study of the Endangered Antillean manateeTrichechus manatus manatusin French Guiana

Spatial and seasonal variations in surface water temperature and salinity in the Mexico‐Belize riverine estuary: Possible comfort conditions for manatees?

Reasons for seagrass optimism: Local ecological knowledge confirms presence of dugongs

Contact Info

Product

Resources

About