Working Paper: NBER ID: w29014
Authors: M. Scott Taylor
Abstract: Orcinus Orca is the world's largest predator, and simultaneously a significant tourist asset and cultural icon for much of the Pacific Northwest. In the past two decades, the Southern Resident Killer whales (SRKW) have declined by more than 25 percent, and this population appears on a slow-motion path towards extinction. This paper combines elements from biology and economics to put forward a new methodology for investigating their collapse and presents empirical work supporting its novel explanation - the Orca Conjecture. The key mechanism is ecological - Gause's law of competitive exclusion - combined with a shock coming from booming trade with Asia. Using three different empirical methods drawn from economics, I find the attendant noise disturbance from increased ship traffic post-1998 has lowered births and raised deaths significantly, placing the SRKW on a slow-motion path towards extinction.
Keywords: No keywords provided
JEL Codes: F18; F64; Q37; Q5; Q57
Edges that are evidenced by causal inference methods are in orange, and the rest are in light blue.
| Cause | Effect |
|---|---|
| increased ship traffic since 1998 (L91) | lower birth rates of Southern Resident Killer Whales (SRKW) (J19) |
| increased ship traffic since 1998 (L91) | increased death rates of Southern Resident Killer Whales (SRKW) (I12) |
| increased ship traffic (R41) | lower hunting productivity for Southern Resident Killer Whales (SRKW) (Q22) |
| lower hunting productivity for Southern Resident Killer Whales (SRKW) (Q22) | competitive disadvantage against Northern Resident Killer Whales (NRKW) (Q26) |
| competition for shared prey resources between SRKW and NRKW (Q27) | exacerbates decline of Southern Resident Killer Whales (SRKW) population (Q22) |
| increased vessel traffic (R41) | negative effects on SRKW reproductive success (I12) |
| only a significant increase in salmon availability (Q22) | offset negative impacts of vessel disturbance (Q22) |