Stock Complexes for Fisheries Management in the Gulf of Mexico

Abstract

The Magnuson–Stevens Fishery Conservation and Management Act of 2006 required that regional fishery management councils implement annual catch limits and accountability measures for all federally managed stocks by 2011. Many managed species are data limited and no formal stock assessment has been done for them. One possible approach to managing unassessed species is to assign them to assemblages that are managed as units. The utility of this approach was evaluated using fishery‐dependent and fishery‐independent data from the Gulf of Mexico. Multivariate statistical analyses revealed several consistent assemblages among the 42 reef fish species managed by the Gulf of Mexico Fishery Management Council. Pearson correlation matrices, nodal analyses, and a weighted mean cluster association index integrated results across cluster analyses and provided additional guidance regarding the placement of rare species into groups. Productivity–susceptibility analysis and life history were also considered, as differences in productivity, vulnerability, life history, and other population‐dynamic parameters for the species within complexes might imply different population responses to a similar change in fishing mortality. Identified linkages between species also provide guidance for the impacts of regulations on multispecies fisheries.Received December 31, 2014; accepted February 18, 2015

The importance of spawning behavior in understanding the vulnerability of exploited marine fishes in the U.S. Gulf of Mexico

“…Life history parameters included maximum age (A max ), maximum weight (W max ) and maximum length (L max ), von Bertalanffy growth coefficient (k), asymptotic length (L inf ), age (A m ) and length at maturity (L m ), and rate of natural mortality (M) (Table 1). These parameters were chosen, because they have been shown to be directly associated with vulnerability to fishing pressure, and they are commonly used in productivity-susceptibility analyses, stock assessments, and in defining species stock complexes (Patrick et al, 2009;Robinson, 2015;Farmer et al, 2016). The reported values were specific to the GOM unless there were no data, in which case information from the Atlantic or Caribbean was used.…”

“…The U.S. Gulf of Mexico (GOM) presents an ideal opportunity to answer important questions about relationships between life history traits, reproductive behavior, and the vulnerability of exploited marine fishes during the spawning season. The GOM is a highly productive system that supports a diverse set of taxa (i.e., numerous families) of highly exploited fish species that exhibit a wide range of life history strategies and reproductive patterns (Farmer et al, 2016;Biggs et al, 2017). There is extensive information on life history characteristics for most managed species, and the majority of fisheries in state and federal waters rely heavily upon life history data as the basis for assessments of both data-limited and data-rich stocks (Sagarese et al, 2015;SEDAR, 2016a).…”

Protecting juveniles, spawners or both: A practical statistical modelling approach for the design of marine protected areas

“…Furthermore, when some fish populations are data-limited compared to others, it is more efficient to manage species complexes rather than individual fish populations (Kruse et al, 2005). For instance, fisheries management is greatly streamlined when harvest catch limits can be K E Y W O R D S fish habitat, geostatistical generalized linear mixed models, Gulf of Mexico, large monitoring database, marine conservation, marine protected areas, spatial generalized additive models, species complexes established for species complexes rather than individual fish populations (Farmer et al, 2016). In this context, SDMs predicting the juvenile and spawner hotspots of species complexes would be beneficial to resource managers.…”

Vessel monitoring systems (VMS) reveal an increase in fishing efficiency following regulatory changes in a demersal longline fishery

“…This fishery primarily targets gag grouper (Mycteroperca microlepis) and red grouper (Epinephelus morio) as well as tilefishes (Caulolatilus spp.) and a complex of other deep-and shallow-water groupers (Farmer et al, 2016;Supplementary material Appendix Table A.1), with 2015 ex-vessel revenue of $28 million (NMFS, 2016). In 2010, an individual fishing quota (IFQ), or catch shares, system was implemented to avoid continuation of "… higher than necessary levels of capital investment, increased operating costs, increased likelihood of shortened-seasons, reduced safety at-sea, wide fluctuations in grouper supply, and depressed ex-vessel prices; leading to deteriorating working conditions and lower profitability for participants."…”