Interpreting spotted dolphin age distributions
Previous work has determined the age distribution from a sample of spotted dolphins (Stenella attenuata) killed in the eastern Pacific tuna purse-seine fishery. In this paper we examine the usefulness of this age distribution for estimating natural mortality rates. The observed agedistribution has a deficiency of individuals from 5-15 years and cannot represent a stable age distribution. Sampling bias and errors in age interpretation are examined as possible causes of the "dip" in the observed age structure. Natural mortality rates are estimated for the 15+ age classes based on the assumption that these are sampled representatively. The resulting annual survival rate <D.82) is too low to allow population growth, given what is known about dolphin reproductive rates. (PDF contains 30 pages.)
| Main Authors: | , |
|---|---|
| Format: | monograph biblioteca |
| Language: | English |
| Published: |
NOAA/National Marine Fisheries Service/Southwest Fisheries Science Center
1984
|
| Subjects: | Ecology, Conservation, Fisheries, Spotted dolphins, Stenella attenuata, seining, by catch, tuna fisheries, |
| Online Access: | http://hdl.handle.net/1834/20264 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|