American manatees adjust their diet composition and trophic niche breadth across different coastal regions
Abstract Marine mammals can exhibit high plasticity in foraging strategies, but how such plasticity is driven by environmental conditions is poorly understood. The American manatee ( Trichechus manatus ), a large, endangered herbivore, inhabits marine, estuarine, and freshwater environments. To better understand their resource use, we analyzed dietary differences across three large Brazilian regions—the Northern Coast (NC), Dry‐Northeastern Coast (Dry‐NEC), and Humid‐Northeastern Coast (Humid‐NEC). The δ 13 C and δ 15 N values of manatee tissues increased from the NC to the Northeastern Coast. Stable isotope mixing models revealed that manatees from the Dry‐NEC feed almost exclusively on seagrasses, while those from the NC rely predominantly on saltmarsh vegetation. In the Humid‐NEC, manatees had a notable contribution from macroalgae, and exhibited the greatest dietary and habitat use diversity among the regions. These spatial patterns advance our understanding of large‐scale habitat use, guiding the establishment of marine protected areas to safeguard manatees and their habitats.
Authors
- Leandro L. Ciotti
- Vítor Luz Carvalho (ORCID: https://orcid.org/0000-0001-6765-0559)
- Alexandra Fernandes Costa (ORCID: https://orcid.org/0000-0001-7560-0113)
- João Carlos Gomes Borges (ORCID: https://orcid.org/0000-0002-0033-6781)
- Camila Carvalho de Carvalho (ORCID: https://orcid.org/0000-0002-6765-942X)
- Silvina Botta
- Renata Emin‐Lima (ORCID: https://orcid.org/0000-0002-5593-1449)
- Fábia de Oliveira Luna (ORCID: https://orcid.org/0000-0001-8960-3462)
- Miriam Marmontel (ORCID: https://orcid.org/0000-0003-3747-9548)
- Emma Deeks (ORCID: https://orcid.org/0000-0003-2552-7848)
- Margareth Copertino
- Fernanda Niemeyer Löffer Attademo
- Eduardo Resende Secchi
- Pavel Kratina
Institutions
- Universidade Federal do Rio Grande (BR)
- Queen Mary University of London (GB)
- Universidade Federal da Paraíba (BR)
- University of Cambridge (GB)
- Bridge University (SS)
- Instituto Sócioambiental (BR)
- Instituto Chico Mendes de Conservação da Biodiversidade (BR)
- Instituto de Desenvolvimento Sustentável Mamirauá (BR)
- Fundação de Estudos e Pesquisas Aquáticas (BR)
- Universidade Federal Rural do Semi-Árido (BR)
Publication Details
- Journal
- Limnology and Oceanography Letters
- Published
- 2026-05-01
- DOI
- https://doi.org/10.1002/lol2.70127
- Primary Topic
- Marine animal studies overview
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- Conselho Nacional de Desenvolvimento Científico e Tecnológico