Centro de Estudios para la Conservación de Ecosistemas Marinos

Chiloé Small Cetacean Project, northern Patagonia, Chile

The biodiversity in the Chiloense Ecoregion is being  threatened by increased industrial activities and overexploitation of marine resources. The Chiloé Small Cetacean Project arises from the need to monitor and address the effects of human activities on the marine ecosystem in this region. It comprises four main areas of research:

i) population status and habitat use,

ii) passive acoustic monitoring,

iii) immune response and microorganisms, and

iv) land-based observations of human-animal interactions.


Population status & habitat use


We began this study of the distribution and population ecology of small cetaceans in the Chiloé Archipelago in 2001 to help address some of the most pressing data deficiencies and conservation concerns for these species, at least on a local scale. The project focuses on Chilean dolphins (Cephalorhynchus eutropia), Peale's dolphins (Lagenorhynchus australis) and Burmeister's porpoises (Phocoena spinipinnis), but other marine mammals and sea birds are also recorded. Principal aims of our project are; i) to determine the abundance, and ranging patterns of the two dolphin species, ii) to identify important habitat for small cetaceans and provide recommendations for appropriate spatial management actions, iii) to identify threats to the local dolphin and porpoise populations, and iv) to maintain the first long-term population study of small cetaceans in southern Chile which will allow for the status of populations and their dynamics to be monitored.

Passive acoustic monitoring


The passive acoustic monitoring (PAM) project emerged out of the need to monitor the small cetacean populations year-round in a cost-effective and logistically feasible manner. We use static PAM techniques to identify temporal and spatial patterns of occurrence and habitat use of Chilean dolphins in areas with varying intensity of anthropogenic activities. C-PODs (autonomous acoustic dataloggers) have been used to monitoring continuously for the dolphins' narrow-band high frequency (NBHF) echolocation clicks allowing acoustic detection rates to be established as proxy for dolphin occurence and area use. Now that we know that static PAM techniques work at Chiloé we are in the process of expanding their application to other species (Peale's dolphins and Burmeister's porpoises) as well as geographically. We are working on acoustic discrimination of these sympatric NBHF clicking species.


Immune response & microorganisms


Several human activities overlap with important  habitat for small cetaceans in southern Chile. Aquaculture and other anthropogenic activities may increase the risk of infectious diseases in cetaceans by increasing their exposure to bioactive substances (e.g. antibiotics) or adding other stressors to the environment. This project is pioneering novel techniques to investigate the effects of human activities on cetaceans, particularly in near‐shore populations that utilise degraded coastal habitats. Using minimally invasive skin biopsies and molecular techniques, we characterise the composition and diversity of the skin microbiomes of small cetaceans, and determine the expression of key immune genes to evaluate the exposure to and influence of anthropogenic activities on the different species.

Land-based monitoring


Land-based observations of dolphins are a low cost, non-invasive technique to study fine-scale movement patterns and dolphin behaviour without disturbing the study animals. The hills surrounding some of the core habitat for Chilean dolphins offer a great vantage point to track them visually using binoculars, video recordings and a theodolite (surveyor's instrument). The observational and tracking data are used to investigate dolphin behaviour in relation to group size and group stability, spatial and environmental factors as well as the intensity of anthropogenic activities (e.g. mussel farming) in Bahiá Yaldad. Land-based studies make good dissertation projects where suitably motivated students learn different behaviour sampling  and spatial mapping techniques and can work quite independently to collect data for their theses.