Resolving the measurement uncertainty paradox in ecological management

TL;DR

This paper investigates the paradox of how different decision-making paradigms handle present measurement uncertainty in ecological management, revealing flaws in traditional methods and proposing POMDP-based solutions that improve sustainability and economic outcomes.

Contribution

The study demonstrates that POMDP methods effectively resolve the measurement uncertainty paradox, outperforming traditional approaches in ecological management scenarios.

Findings

Traditional methods often lead to over-exploitation under uncertainty.

POMDP-based management reduces risk of stock collapse.

POMDP approaches generate higher economic value.

Abstract

Ecological management and decision-making typically focus on uncertainty about the future, but surprisingly little is known about how to account for uncertainty of the present: that is, the realities of having only partial or imperfect measurements. Our primary paradigms for handling decisions under uncertainty -- the precautionary principle and optimal control -- have so far given contradictory results. This paradox is best illustrated in the example of fisheries management, where many ideas that guide thinking about ecological decision making were first developed. We find that simplistic optimal control approaches have repeatedly concluded that a manager should increase catch quotas when faced with greater uncertainty about the fish biomass. Current best practices take a more precautionary approach, decreasing catch quotas by a fixed amount to account for uncertainty. Using comparisons to both simulated and historical catch data, we find that neither approach is sufficient to avoid stock collapses under moderate observational uncertainty. Using partially observed Markov decision process (POMDP) methods, we demonstrate how this paradox arises from flaws in the standard theory, which contributes to over-exploitation of fisheries and increased probability of economic and ecological collapse. In contrast, we find POMDP-based management avoids such over-exploitation while also generating higher economic value. These results have significant implications for how we handle uncertainty in both fisheries and ecological management more generally.