Harbor seals from the air: Aerial surveys allow us to estimate their number and occurrences.
Harbor seals in a creek: Some harbor seals sometimes visit creeks during salmon runs to feed.
Harbor seal resting: Harbor seals frequently haul-out on land
for many reasons, including to rest.
Harbor seal on logs: Harbor seals haul-out on many places, including rocky beaches and floating logs.
Harbor seal molting: Harbor seals molt their fur on a seasonal basis.
Transmitter on head: Transmitters allow us to recover data; they fall off when seals molt in autumn.
Publications
Graphical abstracts of selected papers
In this page you can review graphical abstracts from selected papers authored or co-authored by members of the Marine Mammal Ecology Lab . Clicking on the figure will open a new window with the pdf file of the paper or, due to copyright, a link to it. You can read all the pee-reviewed papers by using the drop-down menu of the Publications tab in the top menu.
Papers with no student authors
Harbour seal DNA diet percent averages (RRA) for all of the Salish Sea samples combined. Please note that considerable diet variability exists between haulout sites and regions in the Salish Sea. The DNA-based dataset described herein contains records from 4,625 harbour seal scats representing 52 haulout sites, 7 years, 12 calendar months, and a total of 11,641 prey identifications. Prey morphological hard parts analyses were conducted alongside, resulting in corresponding hard parts data for 92% of the scat DNA samples. (from Thomas et al. 2022 Sci Data).
Mean acoustic detection rates of harbor porpoises in the Baltic Sea. One of the largest ever passive acoustic monitoring studies has been carried out by eight Baltic Sea nations to estimate the abundance of the critically endangered Baltic Proper harbour porpoise for the first time. By logging porpoise echolocation signals at 298 stations during May 2011–April 2013, calibrating the loggers’ spatial detection performance at sea, and measuring the click rate of tagged individuals, an abundance of 71–1105 individuals (95% CI, point estimate 491) was estimated during May–October within the population's proposed management border. (from Amundin et al. 2022 Ecol Evol).
Monthly consumption (in millions of fish) of age-0 Chinook (top) and coho salmon (bottom) eaten by harbor seals in the Puget Sound during 2016-2018. The purple series shows model simulation estimates using prey size data from nearshore areas, while the blue series shows estimates using prey size derived from otoliths extracted from seal scat samples. Solid lines show median estimates and dashed lines depict the 95% confidence intervals for each series. (from Nelson et al. 2021 Can J Fish Aquat Sci).
Papers by graduate students
Map of the study site. Stars indicate where samples of scat from North American river otters (Lontra canadensis) were collected (from Buzzell et al. 2023 Fish Bull).
Odds of individual harbor seal foraging success relative to visits to Whatcom Creek during salmon runs. There was no relationship between the odds of a successful foraging attempt for each of the 170 individual harbor seals and the number of times that they visited the creek (from Freeman et al. 2022 Sci Rep).
Harbor seal average specialization values and 95%CIs relative to sex. Relative specialization results indicated that the behavior of both sexes was similar in the spring but diverged in the summer and fall (from Voelker et al. 2020 Ecol Evol).
Papers by undergraduate students
Principal component analysis of the harbor seal diet proportions of the most common prey fish orders. (Females = black, Males = gray. Seasons: E = early, L = late. Ellipses represent 68% of the probability distribution around the mean.) Males and females showed strong and consistent differences in their diet. (from Schwarz et al. 2018 Ecol Evol).
Average distance that different boat types passed by harbor seal haul-out sites. (Error bars indicate SD. NMBs = non-motorized boats, MMBs = vessels 1 to 10 m in length, and LMBs = vessels > 10 m in length.) The distance at which vessels passed was related to the interaction of boat type and haul-out site. (from Cates & Acevedo-Gutiérrez 2017 Aquat Mamm).
Sociograms of female-female interactions during feeding and non-feeding states. During non-feeding female associations split into two main subgroups with weak connections between them, whereas during feeding the associations indicated a single, strongly connected group (from Moreno & Acevedo-Gutiérrez 2016 R Soc Open Sci)