[MARMAM] New Paper: Spatial behavioural response of coastal bottlenose dolphins to habitat disturbance in southern Brazil

Macarena Agrelo maca.agrelo at gmail.com
Mon Sep 9 11:23:43 PDT 2019

Dear Colleagues,

We are pleased to announce the publication of the following paper "Spatial
behavioural response of coastal bottlenose dolphins to habitat disturbance
in southern Brazil" in Aquatic Conservation: Marine and Freshwater


1. A small population of coastal bottlenose dolphins (*Tursiops truncatus
gephyreus*) inhabits the inland waters of Laguna, southern Brazil. A subset
of this population interacts with artisanal fishermen. This specialized
foraging tactic structures dolphin society into “cooperatives”—participants
of the interaction—and “non-cooperatives”—non-participants.

2. Between 2012 and 2015, a bridge was constructed in Laguna over an
important core area for dolphins. Photo-identification and georeferenced
data collected on boat surveys, conducted both before and during bridge
construction, were used to evaluate changes in both “cooperative” and
“non-cooperative” dolphin distribution.

3. Changes in dolphin distribution were analysed with kernel densities and
hurdle models. A grid of 120 1-km² cells was used to model dolphin
distribution and the minimum distance from the grid cell centre to the
bridge and to the area of gillnet use were defined as explanatory variables
of human activities. Habitat descriptor (depth and distance) from the
lagoon margin were also considered in the model procedure.

4. Dolphin distribution patterns shifted between periods. A core area used
by “non-cooperative” dolphins near the bridge construction works
disappeared. The effects of habitat descriptor and anthropogenic activity
on dolphin distribution also differed between periods. Before bridge
construction, the abundance of “non-cooperative” dolphin was higher close
to the bridge area (p < 0.05). During bridge construction, the presence of
“cooperative” and “non-cooperative” dolphins decreased significantly with
the distance from gillnet fishing activity (p < 0.01; p < 0.001).

5. This study highlights the importance of accounting for individual
variations in response when assessing the effects of a habitat disturbance,
or when implementing conservation plans.

Keywords: anthropic impacts, bottlenose dolphin, conservation,
distribution, habitat disturbance, hurdle models

Agrelo, M., Daura‐Jorge, F. G., Bezamat, C., Silveira, T. C., Volkmer de
Castilho, P., Rodrigues Pires, J. S., & Simões‐Lopes, P. C. (2019). Spatial
behavioural response of coastal bottlenose dolphins to habitat disturbance
in southern Brazil. *Aquatic Conservation: Marine and Freshwater Ecosystems*

The article is available at the link below:

Best regards,
Macarena Agrelo

*Macarena Agrelo *[image: ]
Doutoranda em Ecologia
Laboratório de Mamíferos Aquáticos - LAMAq
Universidade Federal de Santa Catarina - UFSC - Brasil
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