Fishermen, markets, and population diversity

Abstract

a b s t r a c tFishing impacts biodiversity on multiple levels, potentially resulting in unintended feedbacks to the economic performance of the fishery over time. For example, targeting observable traits within a population can impact genetic diversity and targeting valuable species can impact biodiversity at the ecosystem level. The bioeconomic literature, however, has given little attention to the effect of fishing on population diversity, even though population diversity contributes to ecosystem services and estimates of population extinction rates are three orders of magnitude higher than species extinction rates. Here we develop a stochastic bioeconomic model that links the harvest of multiple salmon populations in a single commercial fishery to the trajectory of population diversity in a salmon stock complex. We parameterize our model with biological and economic data from the Copper River Chinook salmon fishery. We show that markets can incentivize the degradation of population diversity, reducing infra-marginal fishery rents, and increasing variability in economic returns. We also show that second-best management can conserve population diversity and improve welfare. Furthermore, depending on fishermen's time preferences, this management strategy is potentially self-financing.

Temporal stability and assignment power of adaptively divergent genomic regions between herring (Clupea harengus) seasonal spawning aggregations

“…Seasonal spawning components exhibit different growth rates, abundance trends (Harma, Brophy, Minto, & Clarke, 2012;, and morphologies (Messieh, 1975), and are managed separately in the Gulf of St. Lawrence (GSL) (DFO, 2016a). The reasons for such shifts are largely unknown but may be aggravated by changing temperatures (Arula, Raid, Simm, & Ojaveer, 2016;Melvin et al, 2009) or seasonally shifting fishing pressure (Jardine & Sanchirico, 2015). The reasons for such shifts are largely unknown but may be aggravated by changing temperatures (Arula, Raid, Simm, & Ojaveer, 2016;Melvin et al, 2009) or seasonally shifting fishing pressure (Jardine & Sanchirico, 2015).…”

“…Shifts in the relative abundance of these two components have recently occurred in Atlantic Canada: spring spawning herring have declined substantially in the GSL (DFO, 2016a) and off Newfoundland (DFO, 2016b), and almost entirely disappeared from the coast of Quebec (DFO, 2002). The reasons for such shifts are largely unknown but may be aggravated by changing temperatures (Arula, Raid, Simm, & Ojaveer, 2016;Melvin et al, 2009) or seasonally shifting fishing pressure (Jardine & Sanchirico, 2015).…”

Beyond Biomass: Valuing Genetic Diversity in Natural Resource Management

“…Protection of biodiversity is a cornerstone of conservation and renewable resource management. Although the economics literature has historically focused on the problem of maintaining a diverse set of species (e.g., Weitzman ) recent research also highlights the importance of diversity within a species population (Eikeset et al ; Jardine and Sanchirico ; Zimmermann and Jørgensen ). Genetic differences are the foundation for such diversity, combining with environmental variation to produce a portfolio of traits across individuals.…”

“…Jardine and Sanchirico () use such a continuous‐trait model to examine how markets incentivize the degradation of early‐returning runs of a fishery. Although they provide a first look at how economic factors can influence the portfolio of a stock complex, the behavior (and thus genetics) of each subpopulation is assumed to be fixed —the only diversity dimension considered is the relative biomass of each subpopulation.…”