Last updated on 27 March 2018
A benchmark stock assessment for red grouper in the US South Atlantic region was peer reviewed through the Southeast Data, Assessment, and Review (SEDAR) process with data through 2008 (SEDAR 2010). Members of the data and assessment teams included state and federal agency personnel and representatives from the South Atlantic Fishery Management Council (SAFMC) and Gulf of Mexico Fishery Management Council (GMFMC) Science and Statistical Committees (SSC). The peer review panel consisted of members from the Center for Independent Experts (CIE), plus federal agency and Council representatives. The preferred model was the Beaufort Assessment model, a statistical catch at age model used commonly on the US Atlantic and Gulf coasts for a wide range of species, such as menhaden, black sea bass, and several grouper species. Input data included annual removals (harvest and discards) from four fishery sectors (2 commercial, 2 recreational), sector specific length at age data, and three fishery dependent and two fishery independent indices of abundance. Uncertainty in model results was investigated using a range of sensitivity runs to evaluate assumptions regarding data inputs and model configuration, as well as a retrospective analysis. Projections across a range of fishing mortality rates investigated harvest and stock status using both SSB methods. In 2017 the model was updated with data through 2016 using a “standard” assessment, which is based on the benchmark accepted base run, but allows minor modifications to the data and model configuration (SEDAR 2017).
Last updated on 23 January 2018
Biological reference points were originally defined for species managed under the SAFMC snapper-grouper fishery management plan through the Comprehensive Sustainable Fisheries Management Act Amendment (SAFMC 1998), but were more recently updated for red grouper under Amendment 24 (SAFMC 2011). The 2010 stock assessment and SSC recommended managing the fishery based on MSY-based reference points (SEDAR 2010). The 2010 stock assessment determined that the stock was overfished and overfishing was occuring (SAFMC 2011) so Amendment 24 (SAFMC 2011)
established a 10-year rebuilding period for the stock, and defined annual catch limits (ACL) and accountability measures to minimize the potential for overfishing in the future. A recent stock assessment update concluded the stock is still overfished, and stock projections conducted during the assessment indicate the stock will not recover during the originally established rebuilding deadline of 2020 (SEDAR 2017). The ACL for the stock is set equal to the harvest when fishing at 75% of FMSY, and is allocated among sectors as 44% commercial and 56% recreational (SAFMC 2011).
Last updated on 23 Jan 2018
SEDAR 2010 and the SAFMC SSC recommend using MSY-based reference points. Amendment 24 (SAFMC 2011) established a fishing mortality threshold as the fishing mortality rate that achieves maximum sustainable yield (FMSY). The biomass target is the spawning biomass that achieves maximum sustainable yield (SSBMSY), and the associated MSST is 0.75*SSBMSY. Spawning Stock Biomass (SSB) is estimated as the combined male and female mature biomass (SEDAR 2017). The 2017 stock assessment reports these values as FMSY = 0.12, SSBMSY = 3183.4 t , and MSST = 2387.6 t.
Last updated on 27 March 2018
The 2017 stock assessment indicated that the stock remained overfished with overfishing still occurring. Current fishing mortality, calculated as the geometric mean of the most recent three years, was estimated at F2013-2015 = 0.187, which exceeds the overfishing limit (FMSY = 0.12) by 54%. Spawning biomass in the terminal year of the assessment was estimated at 911 t, which represents 38.1% and 28.6% of the MSST and SSB target, respectively. Commercial landings of red grouper in the SAFMC management area in 2015 were reported as 58.4 ton (SEDAR 2017). In 2016, commmercial harvesters reported only 23.7 ton of red grouper through the quota monitoring program (NMFS 2017).
Last updated on 27 Mar 2018
Spawning biomass of red grouper in the US South Atlantic exceeded 2,500 ton in the mid 1970s, but declined rapidly to a time series low of just 509 ton by 1988. Subsequently, spawning biomass rebounded gradually to over 1,400 ton by 2003, and then more quickly to a time series high of nearly 3,000 ton by 2007. Following this peak, spawning biomass fell sharply by more than 50% in just three years. From 2010 to 2015, biomass has continued to decline, but at a slower rate. Spawning biomass in 2015 was estimated at 911 ton (SEDAR 2017).
Fishing mortality rates were modest during the early years of the stock assessment, remaining below F = 0.35 from 1976 to 1982. By 1984, harvest rates had increased to a time series high of F = 0.80. Since that time, mortality has followed a generally declining trend over time, although with substantial interannual variability. Years of below average harvest mortality in 1991 and 2005 (F = 0.22 and 0.17, respectively) were followed shortly after by high mortality years in 1993 and 2009 (F = 0.59 in both years). Fishing mortality in the terminal year of the assessment was estimated at F = 0.181, with a three year geometric mean value of F2013-2015 = 0.187 (SEDAR 2017).
Commercial landings were reported at over 400 ton in the first year of the stock assessment (1976), but remained generally stable between 300 mt and 400 ton per year through the 1980s. Landings dropped sharply in the early 1990s, falling below 200 ton for the years 1992 to 1994, before returning to previous levels during 1995-2004. A sharp dip in landings to 215 ton in 2005 was followed by a spike to nearly 600 ton in 2007-2008. Landings have fallen considerably since this peak, dropping by more than 50% by 2010 and continuing to drop by approximately 25-33% per year since then.