Naslov
Habitat modelling using whale-watching data: a good option?

Autori
Kovacic, Iva ; Torres, Benjamin ; Cosentino, Andrea ; Majnaric, Nina ; Tassara, Luca ; Acosta, Marta

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Abstract book: 27th Annual Conference of the European Cetacean Society / - , 2013, 339-339

Skup
27th CONFERENCE OF THE EUROPEAN CETACEAN SOCIETY, INTERDISCIPLINARY APPROACHES IN THE STUDY OF MARINE MAMMALS

Mjesto i datum
Setúbal, Portugal, 08.04.2013. - 10.04.2013

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
whale watching vessels ; cetaceans ; collecting data

Sažetak
In many areas the only data collected on cetaceans is obtained opportunistically from whale-watching vessels. A number of whale-watching companies regularly collects effort and sighting data on observed species, with databases spanning over long time periods. However, collected data is biased due to the particular ways of finding and following cetaceans. Since the whale watching areas are obviously cetacean hotspots, and the obtained data is often used in habitat modelling, it is of prime interest to know if the resulting models are reliable. We simulated a distribution of a whale species in a landscape: 1. as random distribution and 2. conditional on several environmental variables. We then simulated the probability of collecting the data from the two distributions incorporating three typical walewatching detection methods: visual detection at a set range, acoustical detection at a set range, and approaching a previously known sighting location. Sampling frequency is modeled as a function of distance from the departure point. We applied several different combinations to examine all the probable scenarios, with iterative samplings simulated for the dataset to correspond to 30 days with 4 trips per day. Additionally, a transect survey was simulated. We use the obtained datasets as an input for frequently used habitat modelling approaches: GAMs, GLMs, ENFA and Maxent software. We then compare the obtained model results with the initial simulation conditions and evaluate which sampling schemes could be used for obtaining reliable habitat modeling results. Finall, we apply the results to real data, a 20- year datset of sperm whale observation in Northern Norway, and compare the habitat model for the whole datataset and for the subset fulfilling the constraints found in our simulations.

Izvorni jezik
Engleski

Znanstvena područja
Biologija, Interdisciplinarne prirodne znanosti

POVEZANOST RADA