- Quantifying 60 years of declining European eel (Anguilla anguilla L., 1758) fishery yields in Mediterranean coastal lagoons ICES JOURNAL OF MARINE SCIENCE 2016; 73 (1): 101-110
- Separating recruitment and mortality time lags for a delay-difference production model CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES 2015; 72 (2): 161-165
Quantifying the balance between bycatch and predator or competitor release for nontarget species
2013; 23 (5): 972-983
If a species is bycatch in a fishery targeted at its competitor or predator, it experiences both direct anthropogenic mortality and indirect positive effects through species interactions. If the species involved interact strongly, the release from competition or predation can counteract or exceed the negative effects of bycatch. We used a set of two- and three-species community modules to analyze the relative importance of species interactions when modeling the overall effect of harvest with bycatch on a nontarget species. To measure the trade-off between direct mortality and indirect positive effects, we developed a "bycatch transition point" metric to determine, for different scenarios, what levels of bycatch shift overall harvest impact from positive to negative. Under strong direct competition with a targeted competitor, release from competition due to harvest leads to a net increase in abundance even under moderate levels of bycatch. For a three-species model with a shared obligate predator, the release from apparent competition exceeds direct competitive release and outweighs the decrease from bycatch mortality under a wide range of parameters. Therefore, in communities where a shared predator forms a strong link between the target and nontarget species, the effects of indirect interactions on populations can be larger than those of direct interactions. The bycatch transition point metric can be used for tightly linked species to evaluate the relative strengths of positive indirect effects and negative anthropogenic impacts such as bycatch, habitat degradation, and introduction of invasive species.
View details for DOI 10.1890/12-1316.1
View details for Web of Science ID 000321489100002
View details for PubMedID 23967569