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Item No place to hide: Marine habitat does not determine per- and polyfluoroalkyl substances (PFAS) in odontocetes(Elsevier B.V., 2025-12-10) Stockin KA; Peters KJ; Saltré F; Machovsky-Capuska GE; Betty EL; Tremblay LA; Yi SAs meso- and apex predators in food webs, marine mammals can bioconcentrate persistent environmental contaminants like per- and polyfluoroalkyl substances (PFAS). Although the presence of PFAS is widely reported in the marine environment, there is a lack of data for cetaceans in Oceania. We investigated whether ecological habitat influences bioconcentration patterns across a range of odontocete (toothed whale, dolphin and porpoise) species. We measured PFAS in liver samples (n = 127) from 16 cetacean species representing four families inhabiting four marine habitats along the Aotearoa New Zealand coastline. We analysed six perfluoroalkyl carboxylic acids, ten perfluoroalkyl sulphonic acids and four precursor compounds in the context of sex, body index, habitat and species/family using generalized linear mixed models. Results showed that marine habitat remained a weak predictor of PFAS burden. Instead, biological factors including sex and age class best explained the levels of PFAS detected across all species and habitats. We offer first important insights on PFAS levels across several new taxa globally, including endemic endangered species and poorly described polar vagrants. Our findings further highlight how the ubiquitous nature of PFAS pose a higher risk to odontocetes across different seascapes than previously anticipated.Item Reproductive biology of male common dolphins (Delphinus delphis) in New Zealand waters.(Springer Nature, 2023-10-06) Palmer EI; Betty EL; Murphy S; Perrott MR; Smith ANH; Stockin KA; Siebert UReproductive parameters were assessed in 64 male common dolphins (Delphinus delphis) examined post-mortem from strandings and bycatch in New Zealand between 1999 and 2020. The stages of male sexual maturation were assessed using morphological measurements and histological examination of testicular tissue. Age was determined via growth layer groups (GLGs) in teeth. The average age (ASM) and length (LSM) at attainment of sexual maturity were estimated to be 8.8 years and 198.3 cm, respectively. Individual variation in ASM (7.5–10 years) and LSM (190–220 cm) was observed in New Zealand common dolphins. However, on average, sexual maturity was attained at a similar length but at a marginally younger age (< 1 year) in New Zealand compared to populations in the Northern Hemisphere. All testicular variables proved better predictors of sexual maturity compared to demographic variables (age and total body length), with combined testes weight the best outright predictor of sexual maturity. Reproductive seasonality was observed in male common dolphins, with a significant increase in combined testes weight in austral summer. This aligns with most other studied populations, where seasonality in reproduction is typically observed. Given the known anthropogenic impacts on New Zealand common dolphins, we recommend that these findings be used as a baseline from which to monitor population-level changes as part of conservation management efforts.Item Reproductive biology of female common dolphins (Delphinus delphis) in New Zealand waters(Springer-Verlag GmbH, 2022-11-20) Palmer EI; Betty EL; Murphy S; Perrott MR; Smith ANH; Stockin KA; Crocker DReproductive biology was assessed in 106 female common dolphins (Delphinus delphis) examined post-mortem from stranding and bycatch events along the New Zealand coastline between 1997 and 2019. The average age (ASM) and length (LSM) at sexual maturity was estimated at 7.5 years and 183.5 cm, respectively. The total number of corpora in mature individuals increased with age and appeared to persist throughout life. Ovarian asymmetry was apparent, with the left ovary displaying higher rates of ovulation, and a maximum of 19 corpora recorded for a 24-year-old female. The estimated ovulation and annual pregnancy rates for mature females were 0.39 year-1 and 30%, respectively. Conception and calving occurred year-round, with a weak seasonal increase observed in late austral spring and early austral summer. As these data did not clearly show whether seasonality was present, the gestation, lactation, and resting periods were calculated as either 12.6 or 12.8 months based on the presence/absence of seasonality, respectively. Similarly, calving interval ranged from 3.15 to 3.2 years, depending upon whether seasonality was considered. The estimated LSM of the New Zealand population aligns with other populations globally, although the estimated ASM is younger by approximately 6 months. Other reproductive parameters align with Northern Hemisphere populations, although demonstrate variation, which may reflect adaptations to local conditions such as water temperature and prey availability. As the species is subject to anthropogenic impacts including pollution and bycatch, we suggest our findings be used as a baseline with which to monitor trends in population parameters.