Distribution and habitat use by manatees (Trichechus manatus manatus) in Belize and Chetumal Bay, Mexico

Morales‐Vela, Benjamín; Olivera-Gomez, David; Reynolds, John E.; Rathbun, Galen B.

doi:10.1016/s0006-3207(00)00009-4

Cited by 62 publications

(69 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Flyovers standardized occurred at an altitude of 150 m and a velocity of 140 km.h -1 (coast and estuaries), which is within the minimum range recorded in previous studies (MORALES-VELA et al, 2000;WRIGHT et al, 2002;COSTA, 2006) and corresponds to the minimum safety conditions of the crew during the study. The flyover crew was composed of a pilot, positioned on the left of the plane, two independent observers laterally covering each sampling strip (detection bias) in the rear portion of the plane and an annotator alongside the pilot.…”

Section: Aerial Surveysupporting

confidence: 72%

See 1 more Smart Citation

Pilot aerial study of the marine megafauna in northern coast Alagoas, Brazil

Alves¹,

Borges²,

Araújo³

2013

TropOcean

View full text Add to dashboard Cite

This study aimed to investigate the feasibility of strip-transect aerial survey for the study of the marine megafauna in northern coast of Alagoas, chosen as the pilot area due to the better water clarity and the occurrence of the Antillean manatee. It was sighted 15 dolphins, 13 sea turtles and 10 manatees. From five aspects tested on the experimental flight, three adjustments were necessary on the methodology as following: 1) reduction of the transect angle to 40º to increase the sampling area; 2) constant transects of 1.5 nautical miles from shore to standardize the area of coverage; and 3) transects restricted to the mouths of estuaries due to low visibility in turbid waters. This study demonstrated the effectiveness of aerial surveys for the detection of marine megafauna. However, the adjustments proposed are necessary to minimize the characteristic limitations of each species and/or habitat.

show abstract

Section: Aerial Surveysupporting

confidence: 72%

“…In cases of dubious sightings or imprecise counts of individuals, recounts were performed (LANGTIMM et al, 2011) through circular flights over the location of the sight and imprecise records were discarded. A group was defined as two or more animals (MORALES-VELA et al, 2000).…”

Section: Identification Of Animalsmentioning

confidence: 99%

Pilot aerial study of the marine megafauna in northern coast Alagoas, Brazil

Alves¹,

Borges²,

Araújo³

2013

TropOcean

View full text Add to dashboard Cite

show abstract

“…Because of the previously mentioned habitat and climate differences between the 2 subspecies, seagrasses tend to make up a much larger portion of the manatee diet in Puerto Rico than freshwater and/or estuarine vegetation (Mignucci-Giannoni & Beck 1998). Very little is known of the feeding habits of manatees in Belize, but seasonal differences in lagoon water levels may lead to changes in habitat use (Morales-Vela et al 2000, Auil et al 2007) and consequently diet composition. Little research has been done on the Antillean subspecies, and expanded effort is crucial to provide measures on which to base conservation plans.…”

Section: Resale or Republication Not Permitted Without Written Consenmentioning

confidence: 99%

Feeding preferences of West Indian manatees in Florida, Belize, and Puerto Rico as indicated by stable isotope analysis

Alves-Stanley¹,

Worthy²,

Bonde³

2010

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

The endangered West Indian manatee Trichechus manatus has 2 recognized subspecies: the Florida T. m. latirostris and Antillean T. m. manatus manatee, both of which are found in freshwater, estuarine, and marine habitats. A better understanding of manatee feeding preferences and habitat use is essential to establish criteria on which conservation plans can be based. Skin from manatees in Florida, Belize, and Puerto Rico, as well as aquatic vegetation from their presumed diet, were analyzed for stable carbon and nitrogen isotope ratios. This is the first application of stable isotope analysis to Antillean manatees. Stable isotope ratios for aquatic vegetation differed by plant type (freshwater, estuarine, and marine), collection location, and in one instance, season. Carbon and nitrogen isotope ratios for manatee skin differed between collection location and in one instance, season, but did not differ between sex or age class. Signatures in the skin of manatees sampled in Belize and Puerto Rico indicated a diet composed primarily of seagrasses, whereas those of Florida manatees exhibited greater regional variation. Mixing model results indicated that manatees sampled from Crystal River and Homosassa Springs (Florida, USA) ate primarily freshwater vegetation, whereas manatees sampled from Big Bend Power Plant, Ten Thousand Islands, and Warm Mineral Springs (Florida) fed primarily on seagrasses. Possible diet -tissue discrimination values for 15 N were estimated to range from 1.0 to 1.5 ‰. Stable isotope analysis can be used to interpret manatee feeding behavior over a long period of time, specifically the use of freshwater vegetation versus seagrasses, and can aid in identifying critical habitats and improving conservation efforts.KEY WORDS: Stable isotope · West Indian manatee · Seagrass · Aquatic plants · 13 C · 15 N · Feeding ecology · Mixing model Resale or republication not permitted without written consent of the publisherMar Ecol Prog Ser 402: [255][256][257][258][259][260][261][262][263][264][265][266][267] 2010 many other differences in habitat, climate, and population size that have unique effects on the success of each subspecies. Both subspecies appear to require regular year-round access to a freshwater source (Lefebvre et al. 1989, Olivera-Gomez & Mellink 2005, a requirement that is likely a result of osmoregulatory constraints (Ortiz et al. 1998(Ortiz et al. , 1999. Winter habitat use by Florida manatees is primarily influenced by water temperature, whereby physiological constraints require that they aggregate at natural (springs) and/or artificial (power plant outflows) warm water sources when water temperatures drop below 20°C (Irvine 1983, Worthy et al. 2000, Bossart et al. 2003. This pattern is unnecessary for Antillean manatees since their range lies in the tropics where water temperatures are more constant. Population estimates for the Florida manatee suggest counts as high as 3807 individuals (FWC 2009), whereas Antillean manatees are thought to number fewer than 100 individuals ...

show abstract

“…La bahía es una zona de Conservación Ecológica, Santuario del Manatí (Morales-Vela et al 2000) y ha sido reconocida como área de crianza de larvas de peces (Carrillo et al 2009). En términos ecológicos es un sistema oligotrófico con zonas y episodios de hipoxia derivados del creciente aporte de desechos agrícolas en su zona más interna (Izasa et al 2006).…”

Section: Introductionunclassified

Copépodos planctónicos de la Bahía de Chetumal, Caribe Mexicano: variaciones estacionales durante un ciclo anual

Ruíz-Pineda¹,

Suárez‐Morales

Gasca

2016

Rev. biol. mar. oceanogr.

View full text Add to dashboard Cite

Abstract.-Planktonic copepods are representative members of the coastal and estuarine biota. In Chetumal Bay, western Caribbean, the relevance of monitoring the copepod community at different scales is widely recognized. Zooplankton was sampled monthly during 3 seasons (northerlies, rainy, dry) during a year cycle (1997). The composition and distribution of planktonic copepods and their monthly and seasonal abundance was analyzed to assess the influence of environmental parameters on this community. Each seasonal period was characterized by distinct relative abundance values of the most abundant species. Acartia tonsa was dominant during the 3 seasons, with high relative abundances year-round (67-92%). The ANOSIM (Bray Curtis similarity analysis) showed significant differences of the community among seasons thus confirming a seasonal dynamics; a monthly significant variability was also observed. The PCA (Principal Components Analysis) showed that temperature and salinity explained 82% of the observed variability; additional analyses indicated that salinity best explains the distributional patterns of the species. Two distinct groups were detected, one representing the resident estuarine community with high abundances of A. tonsa, low abundances of A. lilljeborgi, low species richness, and sites of the inner areas of the bay and of nortes (January and November). The second group represents a foreigner coastal-neritic community with low abundances of A. tonsa, presence of A. lilljeborgi, high diversity of species; it includes sites of the dry and rainy seasons plus those of the external zone of the bay. The local dominance of A. tonsa in Chetumal is explained by the low concentration of predators and the low densities of A. lilljeborgi, mostly restricted to areas with higher salinity and also by its probable positive correlation with oxygen concentration which probably limits its populations in a hypoxic system like Chetumal.Key words: Estuaries, zooplankton, copepods, Acartia tonsa, western CaribbeanResumen.-Los copépodos del plancton son representativos de la biota de sistemas estuarino-costeros. En la Bahía de Chetumal, Caribe de México, se reconoce la importancia de su estudio y monitoreo en distintas escalas. Se obtuvieron muestras de zooplancton durante las épocas climáticas de nortes, lluvias y secas de un ciclo anual (1997). Se determinó la composición, distribución y abundancia mensual y estacional de los copépodos para determinar la influencia de algunas variables ambientales sobre esta comunidad. Cada época mostró distintos valores relativos de abundancia de las especies más abundantes. Acartia tonsa fue dominante en las tres épocas, con altos valores de abundancia relativa (67-92%) en todo el ciclo anual. El análisis de ANOSIM (Análisis de Similitud Bray Curtis) mostró diferencias significativas de la comunidad entre épocas confirmando una dinámica estacional; también se observó una variabilidad significativa a escala mensual. El Análisis de Componentes Principales mostró que la temperatura y la salini...

show abstract

Distribution and habitat use by manatees (Trichechus manatus manatus) in Belize and Chetumal Bay, Mexico

Cited by 62 publications

References 10 publications

Pilot aerial study of the marine megafauna in northern coast Alagoas, Brazil

Pilot aerial study of the marine megafauna in northern coast Alagoas, Brazil

Feeding preferences of West Indian manatees in Florida, Belize, and Puerto Rico as indicated by stable isotope analysis

Copépodos planctónicos de la Bahía de Chetumal, Caribe Mexicano: variaciones estacionales durante un ciclo anual

Contact Info

Product

Resources

About