Killer Whales and Marine Mammal Trends in The North Pacific—A Re-Examination of Evidence for Sequential Megafauna Collapse and the Prey-Switching Hypothesis

Springer et al. (2003) contend that sequential declines occurred in North Pacific populations of harbor and fur seals, Steller sea lions, and sea otters. They hypothesize that these were due to increased predation by killer whales, when industrial whaling’s removal of large whales as a supposed primary food source precipitated a prey switch. Using a regional approach, we reexamined whale catch data, killer whale predation observations, and the current biomass and trends of potential prey, and found little support for the prey-switching hypothesis. Large whale biomass in the Bering Sea did not decline as much as suggested by Springer et al., and much of the reduction occurred 50–100 yr ago, well before the declines of pinnipeds and sea otters began; thus, the need to switch prey starting in the 1970s is doubtful. With the sole exception that the sea otter decline followed the decline of pinnipeds, the reported declines were not in fact sequential. Given this, it is unlikely that a sequential megafaunal collapse from whales to sea otters occurred. The spatial and temporal patterns of pinniped and sea otter population trends are more complex than Springer et al. suggest, and are often inconsistent with their hypothesis. Populations remained stable or increased in many areas, despite extensive historical whaling and high killer whale abundance. Furthermore, observed killer whale predation has largely involved pinnipeds and small cetaceans; there is little evidence that large whales were ever a major prey item in high latitudes. Small cetaceans (ignored by Springer et al.) were likely abundant throughout the period. Overall, we suggest that the Springer et al. hypothesis represents a misleading and simplistic view of events and trophic relationships within this complex marine ecosystem.

Perceptions of Procedural and Distributive Justice in the September 11th Victim Compensation Fund

The September l1th Victim Compensation Fund (the Fund) was created in response to the terrorist attacks of September 11, 2001. Much has been written about the Fund, both pro and con, in both popular media and scholarly literature. Perhaps the most widely used term in referring to the Fund is "unprecedented." The Fund is intriguing for many reasons, particularly for its public policy implications and its impact on the claimants themselves. The federal government has never before provided compensation to victims of terrorism through a special master who had virtually unlimited discretion in determining awards. Consequently, this formal allocation of money by a representative of the federal government to its citizens has provided an opportunity to test theories of procedural and distributive justice in a novel context. This article tests these theories by analyzing the results of a study of the Fund's claimants. Part I provides general background, summarizes existing commentary on the Fund, and discusses prior research on social justice that is relevant to the 9/11 claimants' experiences with the Fund. Part II of this article describes the methodology behind the study, in which seventy-one individuals who filed claims with the Fund completed surveys about their experiences with and perceptions of the Fund. Part III discusses the survey results. We found that participants were reasonably satisfied with the procedural aspects of the Fund, such as representatives' impartiality and respectful treatment. Participants were less satisfied, however, with the distributive aspects of the Fund, such as the unequal distribution of compensation and the reduction in compensation if claimants received compensation from other sources (e.g., life insurance). Part IV of this article addresses the implications of the study results for public policy and for theories of social justice.

Tests of the Dynamic Field Theory and the Spatial Precision Hypothesis: Capturing a Qualitative Developmental Transition in Spatial Working Memory

This study tested a dynamic field theory (DFT) of spatial working memory and an associated spatial precision hypothesis (SPH). Between 3 and 6 years of age, there is a qualitative shift in how children use reference axes to remember locations: 3-year-olds’ spatial recall responses are biased toward reference axes after short memory delays, whereas 6-year-olds’ responses are biased away from reference axes. According to the DFT and the SPH, quantitative improvements over development in the precision of excitatory and inhibitory working memory processes lead to this qualitative shift. Simulations of the DFT in Experiment 1 predict that improvements in precision should cause the spatial range of targets attracted toward a reference axis to narrow gradually over development, with repulsion emerging and gradually increasing until responses to most targets show biases away from the axis. Results from Experiment 2 with 3- to 5-year-olds support these predictions. Simulations of the DFT in Experiment 3 quantitatively fit the empirical results and offer insights into the neural processes underlying this developmental change.