Assessment of Skill and Portability in Regional Marine Biogeochemical Models: Role of Multiple Planktonic Groups

Application of biogeochemical models to the study of marine ecosystems is pervasive, yet objective quantification of these models' performance is rare. Here, 12 lower trophic level models of varying complexity are objectively assessed in two distinct regions (equatorial Pacific and Arabian Sea). Each model was run within an identical one-dimensional physical framework. A consistent variational adjoint implementation assimilating chlorophyll-a, nitrate, export, and primary productivity was applied and the same metrics were used to assess model skill. Experiments were performed in which data were assimilated from each site individually and from both sites simultaneously. A cross-validation experiment was also conducted whereby data were assimilated from one site and the resulting optimal parameters were used to generate a simulation for the second site. When a single pelagic regime is considered, the simplest models fit the data as well as those with multiple phytoplankton functional groups. However, those with multiple phytoplankton functional groups produced lower misfits when the models are required to simulate both regimes using identical parameter values. The cross-validation experiments revealed that as long as only a few key biogeochemical parameters were optimized, the models with greater phytoplankton complexity were generally more portable. Furthermore, models with multiple zooplankton compartments did not necessarily outperform models with single zooplankton compartments, even when zooplankton biomass data are assimilated. Finally, even when different models produced similar least squares model-data misfits, they often did so via very different element flow pathways, highlighting the need for more comprehensive data sets that uniquely constrain these pathways.

Voluntary Participation in Regional Fisheries Management Council Meetings

Insufficient and unrepresentative participation in voluntary public hearings and policy discussions has been problematic since Aristotle's time. In fisheries, research has shown that involvement is dominated by financially resourceful and extreme-opinion stakeholders and tends to advantage groups that have a lower cost of attendance. Stakeholders may exhibit only one or all of these traits but can be still similarly advantaged. The opposites of these traits tend to characterize the disadvantaged, such as the middle-ground opinions, the less wealthy or organized, and the more remote stakeholders. Remoteness or distance is the most straightforward and objective of these characteristics to measure. We analyzed the New England Fishery Management Council's sign-in sheets for 2003-2006, estimating participants' travel distance and associations with the groundfish, scallop, and herring industries. We also evaluated the representativeness of participation by comparing attendance to landings and permit distributions. The distance analysis showed a significant correlation between attendance levels and costs via travel distance. These results suggest a potential bias toward those stakeholders residing closer to meeting locations, possibly disadvantaging parties who are further and must incur higher costs. However, few significant differences were found between the actual fishing industry and attendee distributions, suggesting that the geographical distribution of the meeting attendees is statistically similar to that of the larger fishery. The interpretation of these results must take into consideration the limited time span of the analysis, as policy changes may have altered the industry make-up and location prior to our study. Furthermore, the limited geographical input of stakeholders may lend bias to the Council's perception of ecological and social conditions throughout the spatial range of the fishery. These factors should be further considered in the policy-formation process in order to incorporate a broader range of stakeholder input.