Data on how abundance of resource inflows and punishment types affect resource extraction behavior

The data is collected through laboratory experiments on a dynamic common pool resource game, where, in an infinitely repeated number of rounds (i.e., game ended randomly), individuals made decisions about whether to exert a high or a low effort level to extract resources. Experiments were conducted using the student sample (consent provided and ethics approved) at the University of Hawai'i at Mānoa. A total of 8 sessions, 2 for each of the 4 treatments, were run with exactly 20 participants within a session. Individuals made decisions in groups of 10. Communication between any participant was not allowed. A session is randomly assigned (1) to vary whether the inflow of resources at the beginning of each round is high or low, and (2) to allow participants to either financially punish or socially punish defectors. A financial punishment resulted to a loss in profit for the punished while a social punishment displayed the words "You have extracted too much! You're being greedy!" on the computer screen of the punished. Individuals were assigned subject ID numbers and interacted using their subject IDs. The data is useful in understanding how resource inflow and type of punishment affects individual resource extraction behavior. The data could also be combined with other publicly available common pool resource datasets for a meta-analysis on individual behavior in the commons.

Spillover benefits from the world's largest fully protected MPA

Previous research has cast doubt on the potential for marine protected areas (MPAs) to provide refuge and fishery spillover benefits for migratory species as most MPAs are small relative to the geographic range of these species. We test for evidence of spillover benefits accruing from the world's largest fully protected MPA, Papahānaumokuākea Marine National Monument. Using species-specific data collected by independent fishery observers, we examine changes in catch rates for individual vessels near to and far from the MPA before and after its expansion in 2016. We find evidence of spillover benefits for yellowfin (Thunnus albacares) and bigeye tuna (Thunnus obesus).

Impact of two of the world's largest protected areas on longline fishery catch rates

Two of the largest protected areas on earth are U.S. National Monuments in the Pacific Ocean. Numerous claims have been made about the impacts of these protected areas on the fishing industry, but there has been no ex post empirical evaluation of their effects. We use administrative data documenting individual fishing events to evaluate the economic impact of the expansion of these two monuments on the Hawaii longline fishing fleet. Surprisingly, catch and catch-per-unit-effort are higher since the expansions began. To disentangle the causal effect of the expansions from confounding factors, we use unaffected control fisheries to perform a difference-in-differences analysis. We find that the monument expansions had little, if any, negative impacts on the fishing industry, corroborating ecological models that have predicted minimal impacts from closing large parts of the Pacific Ocean to fishing.

Social networks and environmental outcomes

Social networks can profoundly affect human behavior, which is the primary force driving environmental change. However, empirical evidence linking microlevel social interactions to large-scale environmental outcomes has remained scarce. Here, we leverage comprehensive data on information-sharing networks among large-scale commercial tuna fishers to examine how social networks relate to shark bycatch, a global environmental issue. We demonstrate that the tendency for fishers to primarily share information within their ethnic group creates segregated networks that are strongly correlated with shark bycatch. However, some fishers share information across ethnic lines, and examinations of their bycatch rates show that network contacts are more strongly related to fishing behaviors than ethnicity. Our findings indicate that social networks are tied to actions that can directly impact marine ecosystems, and that biases toward within-group ties may impede the diffusion of sustainable behaviors. Importantly, our analysis suggests that enhanced communication channels across segregated fisher groups could have prevented the incidental catch of over 46,000 sharks between 2008 and 2012 in a single commercial fishery.

What determines social capital in a social-ecological system? Insights from a network perspective

Social capital is an important resource that can be mobilized for purposive action or competitive gain. The distribution of social capital in social-ecological systems can determine who is more productive at extracting ecological resources and who emerges as influential in guiding their management, thereby empowering some while disempowering others. Despite its importance, the factors that contribute to variation in social capital among individuals have not been widely studied. We adopt a network perspective to examine what determines social capital among individuals in social-ecological systems. We begin by identifying network measures of social capital relevant for individuals in this context, and review existing evidence concerning their determinants. Using a complete social network dataset from Hawaii's longline fishery, we employ social network analysis and other statistical methods to empirically estimate these measures and determine the extent to which individual stakeholder attributes explain variation within them. We find that ethnicity is the strongest predictor of social capital. Measures of human capital (i.e., education, experience), years living in the community, and information-sharing attitudes are also important. Surprisingly, we find that when controlling for other factors, industry leaders and formal fishery representatives are generally not well connected. Our results offer new quantitative insights on the relationship between stakeholder diversity, social networks, and social capital in a coupled social-ecological system, which can aid in identifying barriers and opportunities for action to overcome resource management problems. Our results also have implications for achieving resource governance that is not only ecologically and economically sustainable, but also equitable.

Leucocyte entry and endothelial E-selectin expression following intradermal Propionibacterium acnes administration

Immune responses in porcine skin to intradermal inoculation of heat-killed Propionibacterium acnes (HKPA), the major bacterial agent associated with human inflammatory acne, were studied. Pigs were chosen as experimental animals because their skin is similar in structure and composition to that of man and because the use of genetically inbred pigs enables leucocytes to be transferred between animals without eliciting rejection responses. Two pigs were sensitized intradermally with 10 mg of HKPA and were challenged 2 weeks later with doses ranging from 1-100 microg of HKPA in various intradermal sites on the ventral aspect of the abdomen. Four further pigs, previously sensitized with Bacillus Calmette-Guérin (BCG) but not HKPA, were challenged with purified protein derivative (PPD) of bovine tuberculin and HKPA. Entry of(51)Cr-labelled peripheral blood lymphocytes (PBLs) over 48 h was studied in all the challenge sites. Peak PBL entry occurred at 4 h, remaining sustained up to 24 h. There was a dose-dependent effect of HKPA on the level of PBL entry, which was antigen-specific, as few leucocytes were seen in PPD-challenge sites in HKPA-sensitized pigs or in HKPA-challenged sites in BCG-sensitized pigs. There was also a substantial influx of(111)Indium-labelled neutrophils into the lesions. Lymphocytes present were predominantly of the CD3(+)CD2(+)T-cell subset, although gammadelta TCR(+)cells were present also, particularly after 24 h. E-selectin was markedly upregulated on dermal endothelium in the P. acnes sites. The histological infiltration and kinetics were similar to those reported in human inflammatory acne.