Fig 1.
Map of the Hawaiian Archipelago.
The four subregions of the main Hawaiian Islands used in the analyses are delineated by dashed lines (inset shows the two principal regions). This map was prepared in ArcGIS 10 and contains open access layers.
Table 1.
Information summary of the two principal regions of the Hawaiian Islands, including the four subregions of the main Hawaiian Islands.
Fig 2.
Example of yield-per-recruit isopleths.
Yield as a function of fishing mortality rates (F) and sizes at first capture (Lc) for the giant trevally Caranx ignobilis. Ycurr represents current yield-per-recruit (in kg) in the fishery and Yeum is the highest possible yield for the current F (0.4). The gray area represents combinations of F and Lc that result in SPRs below 30%. Lc eum is the minimum size limit that will maximize yield while Lc SPR30 is the minimum size limit that will lead to an SPR of 30% given the current F.
Fig 3.
Time-series of average lengths in the exploited phase of the population.
Average lengths displayed for 9 Hawaiian reef fish species in the MHI from 2003 to 2012. Species included in this analysis had at least 30 length observations per year. Data from commercial fishery reports. Species codes are defined in Table 2.
Table 2.
Average size ( and standard error (TL mm) for 19 exploited Hawaiian reef fishes in the 4 main Hawaiian Islands subregions and Northwestern Hawaiian Islands (NWHI) region.
Only estimates with a minimum of n = 10 observations are presented. The simulated average lengths when F = 0 from our population model are also presented (Sim. Ref.,
F = 0).
Table 3.
Life history parameters, mortality rates, and sustainability benchmarks for 19 Hawaiian reef fishes.
See text for description of life history parameters and symbols used. Only species with at least 30 length observations were analyzed. Potential yield increase is the increase in yield that would result if fishing is eumetric (Lc = Lc eumetric). Lc SPR30 is the minimum size at full selectivity for SPR to be equal to 30% under current fishing mortality rate (F). See the S1 Table for life history parameter references.
Fig 4.
(A) Comparison of average lengths in the commercial dataset versus the underwater visual survey dataset for the main Hawaiian Islands (MHI). Closed circles represent average lengths by species in different subregions of the MHI. (B) Average lengths observed in the Northwestern Hawaiian Islands versus simulated unexploited (pristine) average lengths. The red line represents perfect agreement between the two sets of average lengths. Species codes are defined in Table 2.
Fig 5.
Average lengths () and 95% CIs for the main Hawaiian Islands (MHI; open circles) and the Northwestern Hawaiian Islands (NWHI; closed circles).
Two reference points are also displayed: first red bar, (average length when SPR = 30%); second red bar,
(average length when F = 0). Species are ordered by maximum size. Only species with n>30 in the NWHI are presented. Species codes are defined in Table 2.
Fig 6.
Linear regression of total instantaneous mortality rate Z in the NWHI vs. inversed of published maximum age.
Z is derived from average length and is assumed to be equal to M. The slope of this regression is equal to–ln(S) = 3.14, where S (cohort survivorship to maximum age) is 0.043.
Fig 7.
Spawning potential ratio (SPR) for 19 Hawaiian reef fishes in the main Hawaiian Islands.
White bars, SPR < 25%; gray bars, SPR between 25% ≤ SPR ≤ 35%; black bars, SPR > 35%. Species codes are defined in Table 2. Dashed line denotes minimum SPR threshold of 30%.