Final answer:
Conservationists can most effectively help species with high juvenile mortality, low adult mortality, and low fecundity, such as sea turtles, by focusing on keeping adults alive, as this ensures the continuation of reproduction for the species.
Step-by-step explanation:
In a species such as sea turtles, which have high juvenile mortality, low adult mortality, and low fecundity, conservationists can most effectively help by focusing on keeping adults alive. Sea turtles exhibit a life history strategy where they invest more energy into fewer offspring, providing those with greater chances for survival. In this case, since the adults have a better survival rate and their mortality rate is already low, preserving the adults helps ensure they can continue to reproduce. While captive breeding programs can be part of the conservation strategy, they have limitations and are insufficient when considering the large number of species at risk. Moreover, initiatives like controlling the predator population or solely focusing on the juveniles could be less effective when compared to bolstering the survival of the breeding adult population, which is crucial for the continuation of the species.