Dear MARMAMers,
We would like to share this new publication of the Ecology and Conservation of
Marine Megafauna (Ecomega) research team and colleagues.
Secchi ER, Cremer MJ, Danilewicz D and Lailson-Brito J (2021) A Synthesis of
the Ecology, Human-Related Threats and Conservation Perspectives for the
Endangered Franciscana Dolphin. Front. Mar. Sci. 8:617956. doi:
10.3389/fmars.2021.617956
Abstract:
The franciscana is endemic to subtropical coastal waters of Brazil, Uruguay,
and Argentina, and is the only living species of the family Pontoporiidae. It
is regarded as the most endangered cetacean in the western South Atlantic. Five
management units are recognized (Franciscana Management Areas, FMAs – sensu
Secchi et al., 2003a), with abundance estimates ranging from a few hundred to
around 15,000 dolphins. Low reproductive potential and short life span make
this species highly susceptible to current non-natural removal rates. Bycatch
in gillnet fisheries occurs in high levels since the 1960s in Uruguay and 1980s
in Brazil and Argentina. Although other threats exist, such as habitat
degradation that includes physical (noise) and chemical pollution, depletion of
fish stocks and climate change, incidental mortality in gillnets is currently
the greatest threat to franciscanas. Fishing-related mortality ranges from
approximately 100, in FMA I, to more than 1,000 in FMA III, and exceed from
near two (in FMA IV) to more than five times (in FMA III) the maximum allowed
sustainable mortality rate, based on potential biological removal (PBR)
approach. These numbers indicate that the species is unlikely to cope with the
current levels of bycatch and that urgent and extreme reduction on fishing
practice and effort are required to avoid collapse of the franciscana and to
lower its risk of extinction. Current mortality levels and projected declines
resulted in the listing of the franciscana as “Vulnerable” in the IUCN Red
List. Recent fisheries regulations were implemented in areas with extensive
bycatch in Brazil and were expected to improve the species’ conservation
status. There is evidence, however, that this regulation is insufficient to
reduce fishing-related mortality to sustainable levels due to either or both
lack of compliance and inadequate regulation strategies. Here we provide a
comprehensive review on the franciscana ecology and threats and discuss
perspectives for its conservation.
Kind regards,
Eduardo - on behalf of the coauthors
----
Eduardo R. Secchi
Professor Associado
Laboratório de Ecologia e Conservação da Megafauna Marinha-Ecomega
Instituto de Oceanografia
Universidade Federal do Rio Grande-FURG
(53) 3233-6749 (53) 99945-3990
www.furg.br <http://www.furg.br/>
http://lattes.cnpq.br/2134644742559817 <http://lattes.cnpq.br/2134644742559817>
orcid.org/0000-0001-9087-9909 <http://orcid.org/0000-0001-9087-9909>
ResearcherID: D-5038-2013
https://publons.com/researcher/ABF-1191-2020/
<https://publons.com/researcher/ABF-1191-2020/>
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