Pregnancy patterns of pantropical spotted dolphins (Stenella attenuata) in the eastern tropical Pacific determined from hormonal analysis of blubber biopsies and correlations with the purse-seine tuna fishery
| Autor: | Fredrick I. Archer, Nicholas M. Kellar, Marisa L. Trego, Susan J. Chivers |
|---|---|
| Rok vydání: | 2013 |
| Předmět: |
education.field_of_study
Pregnancy Ecology media_common.quotation_subject Population Pantropical Aquatic Science Biology biology.organism_classification medicine.disease Fishery Abundance (ecology) Blubber Stenella attenuata medicine Reproduction education Tuna Ecology Evolution Behavior and Systematics media_common |
| Zdroj: | Marine Biology. 160:3113-3124 |
| ISSN: | 1432-1793 0025-3162 |
| DOI: | 10.1007/s00227-013-2299-0 |
| Popis: | The northeastern offshore population of the pantropical spotted dolphin (Stenella attenuata) in the east- ern tropical Pacific remains listed as depleted under the Marine Mammal Protection act, and recent estimates of abundance show that recovery has been slow. One hypoth- esis for the slow recovery is that continued chase and encir - clement by the tuna fishery negatively affects reproduction. Insufficient life-history sampling in this region over the last two decades makes traditional estimates of reproductive rates impossible. Here, we examine the current reproduc- tive patterns of these dolphins by measuring blubber pro- gesterone (BP) concentrations in biopsy samples to assess pregnancy state. BP was quantified in 212 biopsies from female offshore spotted dolphins sampled between 1998 and 2003 in the northeastern tropical Pacific, and we found that 11.5 % of the biopsied females (mature and immature) were pregnant. The relationship between pregnancy and fishery exposure was analyzed, and we found that pregnant females were exposed to significantly less fishery activ- ity than non-pregnant ones (p = 0.022), suggesting that the fishery may have an inhibitive effect on pregnancy. Spatial analysis indicated that pregnancy was more aggre- gated than random (p < 0.05) at a scale up to 180-nmi, with |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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