Multiple stressors and data deficient populations; a comparative life-history approach sheds new light on the extinction risk of the highly vulnerable Baltic harbour porpoises (Phocoena phocoena).

摘要: Many endangered marine mammal populations are difficult to study, spread out over large areas, and capturing them for branding research purposes would be unethical. Yet, they in urgent need assessment conservation actions. We suggest collecting data from other more abundant of the same species, with careful consideration body size, age at sexual maturity, ecological conditions produce scientifically sound best approximations vital rates deficient populations. The genetically distinct Baltic Sea harbour porpoise population amounts about 500 animals is classified as 'Critically Endangered' according IUCN red list. Data deficiency on nearly all demographic parameters have precluded systematic investigations relative importance stressors affecting viability. took a comparative life history approach investigated phenotypic plasticity somatic seven larger, well studied North Atlantic populations, enabling us approximate missing pieces population. parameterized stochastic, individual-based model, performed viability analysis range biologically realistic parameter values scenarios environmental stressors. baseline scenario was based most representative samples healthy challenged three different levels bycatches. Due high endocrine disruptive contaminants observed porpoises, we also effect possible reduction fecundity. Subsequently, combined effects bycatches reduced fecundity were terms growth rate quasi-extinction risk. viable without anthropogenic However, even lowest estimated bycatch level 7 individuals per year will lead collapse ≤50 probability (0.4-1.0) next century, assuming an intermediate or low (<73%) Adult survival critical mitigation fishery impacts disturbances identified main breeding areas recommended.