An important part of whale conservation is monitoring population recovery. This includes investigations on habitat use and abundance of specific populations and subpopulations. Humpback whales that winter off the coast of Brazil are of key interest due to contact with fisheries, marine traffic, and ocean noise pollution. Bortollotto and colleagues investigated the distribution and density of humpback whales in this region in relation to environmental features, specifically geographical features, unique to this area.
Density surface models were used investigate habitat use and measure abundance of humpback whales. Tracklines from surveys were analyzed using QGIS software. QGIS was used to subdivide these tracklines and several geographic variables were considered: depth, distance to coastline, slope and position in addition to time. The package ETOPO1 was used to extract bathymetry data as well of the depth of the ocean at the place of humpback sightings, and distance to shore. Several habitat models were used, including a habitat use model and an abundance estimation model. Results from these models indicate differences in habitat preferences that are driven by different biological variables such as age, sex, and social group composition. It was found that geographic positioning was highly correlated with sea surface temperature which explained the presence and absence of mothers and calves in this region.
This paper is an example of using GIS to extract pertinent geographic data related to biological trends. Several of the key variables from this study were obtained through GIS packages and software.
Bortolotto G, Danilewicz D, Hammond P, et al (2017) Whale distribution in a breeding area: spatial models of habitat use and abundance of western South Atlantic humpback whales. Mar Ecol Prog Ser 585:213–227. https://doi.org/10.3354/meps12393
