In Other Countries

Franciscana dolphin on foam mat for radio tagging

SDRP staff and volunteers, in collaboration with Disney’s Animal Programs veterinary staff, have traveled to Argentina to assist the Fundación Aquamarina conservation team for six consecutive years.

Conservation scientist Pablo Bordino leads the Aquamarina cadre of students, colleagues, and fishermen.

The goal has been to conduct satellite-linked radio tagging of the endangered franciscana dolphins. Tagging and tracking work during 2007 had suggested residency to Bahia San Blas for up to six months. Subsequent work, using time-depth recorders (TDRs), helped identify diving depth, surfacing patterns, and social patterns.

The franciscana research team in Bahia San Blas, Argentina, March 2010.

Radio tag information is of critical value to conservation scientists. Knowing the depths at which dolphins swim and comparing them to the depths that fishermen set their nets, lets us know how vulnerable these dolphins are to entangling in the nets.

Surfacing and social behavior information can also help conservation scientists develop correction factors for surface and aerial surveys to estimate dolphin abundance.

An adult female franciscana is released by Aquamarina research team members (from left: Leo Berninsone, Ariana Oberti, Natalia Asplanato, and Ignacio "Nacho" Bruno), with guidance from Jason Allen (background), following tagging. Leo, Naty, and Nacho have trained at the SDRP.

We tagged four dolphins (two male/female pairs). Three had TDR tags attached to their dorsal fins and one had a location-only tag attached. The tags continued to transmit for two to nearly six months.

Tracking results indicated that the dolphins remained in a fairly localized area. Most of the dives were shallow, although dives to the bottom did occur. These results agree with previous research we have done in the area.

Locations of satellite-linked radio tagged franciscana dolphin in Argentina

At least one dolphin may be a multi-year resident, and analysis suggested the possibility of long-term breeding associations (which would be quite different from the Sarasota dolphin community or any other dolphin of which we are aware).

Major support for this project was provided by Disney’s Animal Programs and the Chicago Zoological Society. Tags and tag data processing assistance were provided by Dolphin Quest.

Several decades ago fisheries in Argentina, Uruguay and Brazil began to use nylon gillnets. Mortalities due to gill nets now represent the greatest threat to the survival of this dolphin. Methods to reduce their impact on franciscana dolphins are urgently needed.

Franciscana dolphins killed by gill nets in Bahia Samborombon, Argentina

Since 2004, the SDRP and colleagues have been collaborating with Fundación Aquamarina to develop new pragmatic approaches for the conservation of this species in Argentina.

Satellite-linked radio tags on franciscana dolphins show how they use the water column and their habitat where fishing occurs. In collaboration with other organizations, Aquamarina is exploring the potential of modifying gillnets to reduce dolphin bycatch rates..

So-called “reflective nets” may help echolocating dolphins detect these nets at greater distances than they would a standard nylon gillnet. In addition, they are stiffer than a normal net, which may lower the potential for dolphins to become entangled.

Field trials to find safer nets are underway, supported by a host of international groups. If the results from these trials indicate that reflective nets are effective at reducing the by-catch of Francisca dolphins, the research would be expanded to other coastal fisheries where other species of dolphins and porpoises are killed by gill nets.

Information about the population structure of a cetacean species is crucial to species conservation.

Visual surveys from boats and planes can tell us how many dolphins are in the population, tracking can tell us how far individuals in the population range, but genetic information is needed to identify the populations by estimating the amount of inter-breeding, or gene flow, between dolphins from different areas.

Genetic information can tell us whether we are dealing with a single inter-breeding population or several. It can tell us whether a population is genetically isolated from neighboring populations, and for how long it has isolated. Small, genetically isolated populations are the most vulnerable to extinction.

Genetic samples are collected during the SDRP-assisted tagging studies of franciscana dolphins. Using cutting-edge genetic methods using a combination of nuclear and mitochondrial DNA, research by Martín Mendez is underway to identify populations and to estimate gene flow.

The ultimate goal of the project is to identify how oceanographic features influences population structure. This research has identified multiple franciscana populations along the Atlantic coast of South America. Two of the populations are genetically isolated. The populations are separated by ecological and oceanographic features in the environment.

This combination of genetic and environmental data should be invaluable for conservation management decisions.

This work would not be possible without the invaluable support of Fundación Aquamarina and local wildlife authorities. Funding for this project comes from Wildlife Trust, the Sackler Institute for Comparative Genomics of the American Museum of Natural History, the Ocean Giants Program of the Wildlife Conservation Society, and the Chicago Zoological Society.

The Guiana dolphin is distributed along the coastal waters of South America, from Nicaragua to southern Brazil. The species has been designated as Vulnerable under the IUCN criteria. Habitat degradation and loss are thought to be important threats here, possibly linked with recent hydro-electric development.

Guiana dolphin in estuarine waters off Colombia.

Continuing and recently intensified photo-identification research is being conducted in the southern area of the Gulf of Morrosquillo, Colombia. Graduate student Salomé Dussán-Duque, aided by training and support from the SDRP, is attempting to answer basic ecological questions about where they Guiana dolphins feed and breed, and about habitat use associated with what apparently are year-round residency patterns.

Social structure and groups size seems to be influenced by prey abundance. Mother-calf pairs feed in the same locations most of the time, while other dolphins range more widely. Preliminary studies by researchers from the Vancouver Aquarium indicate that Guiana dolphins are highly vocal while foraging and socializing.

The ultimate goal is to develop a management and monitoring plan for this species in the study area. It will be presented to the Ministry of Environment and Territorial Development of Colombia in 2011.

Support for this research was provided over the years by the Chicago Zoological Society’s Chicago Board of Trade Endangered Species Fund (USA), CVS (Colombia), SMRU University of St. Andrews (Scotland), Conservación Internacional (Colombia), Cetacean Society International (USA), Iniciativa de Especies Amenazadas “Programa de Becas Jorge Ignacio Hernández-Camacho”(Colombia) and private funds.

Recent  SDRP graduate student, Dr. Ester Quintana-Rizzo, is conducting research on cetacean species along the Pacific coast of Guatemala.

Dr. Ester Quintana-Rizzo conducting field research on cetaceans in the Pacific Coast of Guatemala.

Dr. Quintana-Rizzo’s initial research indicates that the dolphins are sometimes killed with harpoons normally used by shark fishermen. Other dolphins are killed by illegal gill nets set offshore.

In 2005, 353 fishermen along approximately 255 km of coastline were registered to have at least one “cimbra,” a multi-hook long line for shark fishing with dolphin-meat often used as bait. Gill net mortality has not been studied, but one fisherman reported about 20 dolphin entanglements per month.

Clearly, more research is needed and toward that end, Dr. Quintana-Rizzo has written the first

A group of very acrobatic spotted dolphins sighted in October 2008. Photo by Ester Quintana-Rizzo.

description of cetaceans along Guatemala’s Pacific coast. The report titled “Primer studio sobre la diversitad, distribución, y abundancia de cetaceos en la zona económica exclusiva del Océano Pacífico de Guatemala,” has been distributed to universities, environmental conservation groups, and government conservation agencies.

Dr. Quintana-Rizzo’s research has been supported by the Chicago Zoological Society’s Chicago Board of Trade Endangered Species Fund, Guatemala’s National Commission for Science and Technology, PADI Foundation, and Idea Wild.